Molecular Cytogenetics: Rosetta Stone for Understanding Cancerâ€”Twenty-Ninth G

(CANCER RESEARCH 50, 3816-3825, July 1, 1990] Special Lecture Molecular Cytogenetics: Rosetta Stone for Understanding Cancerâ€”Twenty-ninth G. H. A. Clowes Memorial Award Lecture1

Janet D. Rowley University of Chicago, Chicago, Illinois 60637

This article provides me with an occasion to review our of the viral oncogenes (5). In a sense, each group of investigators progress in a central area of cancer research, namely the genetic gave the other scientific validity. The fact that oncogenes were changes that occur within the cancer cell that are critically directly involved in chromosome translocations demonstrated involved in the transformation of a normal to a malignant cell. that both translocations and oncogenes were critically involved I think it is especially appropriate that three named awards in human cancer. The correlation of the chromosome location (Clowes, Rosenthal, and Rhoads) presented at the 1989 annual of human protooncogenes as well as other cancer related genes meeting of the American Association for Cancer Research went with recurring chromosome rearrangements is shown in Fig. 1. to investigators who have made contributions to our under Cytogeneticists thus progressed from being mere "stamp collec standing of the genetic changes in cancer cells. Clearly, to tors" to being major contributors in cancer research, an im concentrate on genes to the exclusion of cell biology would be provement in status that I welcome. too narrow and short-sighted an approach. Nonetheless, I am The genetic changes that occur in different types of malignant convinced that until we have isolated the genes that are centrally cells are quite varied and clearly several different changes occur involved in at least some of the malignant processes in different in the same cell as it is altered from a normal to a fully cell types, we will be unable to answer the fundamental ques malignant cell. Cytogenetic analysis has been the key to defining tions about malignant transformation. More importantly, we at least two major categories of rearrangements, namely recur will be unable to answer the questions with precision. I will ring translocations and consistent deletions. One of the first limit my consideration to those changes that have been detected translocations, identified in 1972, was the 9;22 translocation in by analyzing the karyotypic pattern of human cancer cells using chronic myeloid leukemia about which I will say more later (6). chromosome banding, and in particular to those found in leu There are now at least 70 recurring translocations that have kemia. been detected in human malignant cells. But the identification We are living in a golden age of the biomedicai sciences. of consistent chromosome deletions has been equally important Increasingly sophisticated instruments and creative scientific because it has provided the absolutely essential information strategies allow remarkably precise understanding of some as regarding the chromosome location of the genes that are in pects of cancer biology. It is clear that during the course of the volved in cancer. I submit that the retinoblastoma gene would last three decades, the scientific community's assessment of the not have been cloned, or at least not yet, if cytogeneticists had role of chromosome changes in the complex process of malig not identified deletions of the long arm of chromosome 13, and nant transformation has changed from considering them to be specifically of band 13ql4, in patients with constitutional chro merely trivial epiphenomena to recognizing their fundamental mosome abnormalities who had a high incidence of retinoblas involvement for at least some tumors. This change in attitude toma (7). This is not to detract from the careful and exciting has occurred for at least two reasons. First, the demonstration work of many scientists in actually cloning the gene, but at of specific recurring chromosome rearrangements, including least they knew where to look (8). This triumph has now been translocations and deletions, that were often uniquely associ joined by the recent cloning of the DCC (deleted in colorectal ated with a particular type of leukemia, lymphoma, or sarcoma carcinomas) gene on chromosome 18; the fact that a gene provided clear evidence that these rearrangements were criti important in the transformation of colorectal cells was located cally involved in malignant transformation (1-3). About 70 on chromosome 18 was the result of cytogenetic analysis of recurring translocations as well as many nonrandom deletions colon cancer cells that revealed that loss of chromosome 18 and other structural abnormalities are listed in the chapter on was a recurring abnormality (9, 10). structural chromosome changes in neoplasia included in Hu It has been a source of great disappointment to me that we man Gene Mapping 10 (4). The evidence for the presence of have progressed so slowly in cloning most of the genes located recurring chromosome abnormalities in a wide variety of human at the breakpoints in the recurring translocations or inversions neoplasms was the result of 30 years of painstaking chromo in human leukemia. This emphasizes the fact that knowing the some analysis by my cytogenetic colleagues around the world. location of the breakpoint is very helpful in selecting the genes The honor attached to this Clowes award should be shared with to use as probes for these rearrangements. However, a chro all of them. mosome band contains at least 5 million base pairs, and the A second, and I believe an even more powerful, force acting likelihood that the DNA probe that you "pull off the shelf is within the general scientific community to reassess the role of at the breakpoint and can detect a rearrangement on Southern karyotypic alterations was the identification of the genes in blot analysis is vanishingly small. The lymphoid leukemias and volved in some of the chromosome rearrangements and the lymphomas are the major exceptions to this slow progress, discovery that some of these genes were the human counterparts because the immunoglobulin genes in B-cell tumors and the T- cell receptor genes in T-cell tumors have provided the essential Received 3/23/90. 1The research described has been supported by Department of Energy Contract DNA probes to clone several dozen translocations (11-13). DE-FG02-86ER60408 and USPHS Grant CA 42557. Presented at the Eightieth Annual Meeting of the American Association for Cancer Research, May 26, Fortunately, the rapid progress being made in mapping the 1989, in San Francisco, CA. human genome, coupled with major advances in working effec- 3816

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Left Side Italic: protooncogene or tumor suppressor gene Plain: growth factor or receptor or cancer related gene n cloned translocation breakpoint t ambiguous location HCK( SRC *BCR ETS2 Right Side PDGFBISIS] RRAS e | region of chromosome duplication i region of chromosome deletion 2 2 1 9 2 O 21 4 recurring breakpoints DBL ^" cloned breakpoints Italic viral integration sites or breakpoint lacking a transcript

Fig. 1. Map of the chromosome location of protooncogenes or of genes that appear to be important in malignant transformation and the breakpoints observed in recurring chromosome abnormalities in human leukemia, lymphoma, and solid tumors. Known protooncogenes are indicated in bold italics and other cancer related genes are listed in standard type. The protooncogenes and their locations are placed to the left of the appropriate chromosome band or region (indicated by a bracket). The breakpoints in recurring translocations, inversions, etc., are indicated with an arrowhead to the right of the affected chromosome band. The solid vertical lines on the right indicate regions frequently present in triplicate; the dashed lines indicate recurring deletions. Recurring viral integration sites and cloned translocation breakpoints with no identified transcripts are indicated to the right of the appropriate band. Genes or recurring breakpoints that have been cloned are identified by #. The locations of the cancer specific breakpoints are based on the Report of the Committee on Structural Chromosome Changes in Neoplasia, Human Gene Mapping 10 (4). [Author's note: Any map of this sort involves selection as to the genes that should or should not be included: I have been relatively conservative. Also for recurring breakpoints and deletions, I have included only those listed as Status I or II in HGM10. This figure was prepared by Michelle S. Rebelsky.) 3817 Downloaded from cancerres.aacrjournals.org on September 27, 2021. © 1990 American Association for Cancer Research. MOLECULAR CYTOGENETICS lively with large pieces of DNA, should lead to the successful chromosome, No. 21 or 22, was involved and was the Ph' really cloning of most of the recurring translocations in the acute the result of a chromosome deletion as had been assumed in leukemias and sarcomas in the next 5 years. the 1960s? With the use of the banding, the Ph' chromosome From the beginning of the cytogenetic analysis of human was shown to involve chromosome 22, and in 1972 I could malignant disease it has been clear that virtually all solid show that it occurred as the result of a translocation rather tumors, including the non-Hodgkin's lymphomas, have an ab than a deletion. This was one of two translocations that I normal karyotype and that some of these abnormalities are discovered in 1972; the other one was actually identified about limited to a given tumor. With regard to the leukemias, it 6 months earlier than the Ph' translocation. It involved chro appeared from studies in the 1960s and early 1970s that only mosomes 8 and 21 and occurred in patients with acute myelo- about 50% had an abnormal karyotype. With improved culture blastic leukemia [t(8;21)(q22;q22)] (17). The Ph' translocation techniques and with the development of processing methods involved chromosomes 9 and 22 [t(9;22)(q34;qll)] (6). They that resulted in longer chromosomes with a larger number of were the first consistent translocations to be discovered in any more clearly defined bands, Yunis et al. (14) have provided human or animal tumor, the first of a great many (1, 2). evidence that a karyotypic abnormality can be detected in Many of the translocations we discovered in the acute mye- virtually all leukemias as well. Some malignant diseases, such loid leukemias were shown to be relatively specifically associ as Hodgkin's disease or multiple myeloma, continue to show a ated with particular morphological subtypes, and in the acute high frequency of normal karyotypes. These diseases are char lymphoid leukemias they were associated with specific immu- acterized by malignant cells with a low mitotic index; therefore nological phenotypes (Tables 1 and 2). Equally important was it is likely that the dividing cells studied do not represent the the observation in the acute myeloid leukemias that two differ malignant cells. ent chromosome bands were consistently affected in each trans- One of the major reasons to concentrate on cloning the genes location and therefore that the critical change involved the involved in rearrangements is that the consistent chromosome abnormal juxtaposition of two very specific genes. These obser changes pinpoint the location of the genes with functions that vations gave rise to the idea that the genes involved in these are critical in the growth potential of that cell type. The chro translocations had restricted functions that were actively ex mosome changes that we concentrate on are present in all of pressed only in the appropriate cell types or stage of differen the malignant cells; thus they are not random events affecting tiation (18). Cloning of a number of translocations in the one or a few cells in the involved tissue. Moreover, they are lymphoid leukemias and lymphomas has validated this concept. clonal in origin and are derived from a single cell in which the It provides the hope that sustains us in our thus far fruitless initial chromosome change occurred. These changes are so search for the genes involved in the translocation breakpoints matic mutations in individuals who otherwise virtually always in acute myeloid leukemia. When we have successfully cloned have a normal karyotype in their uninvolved cells. These obser these breakpoints we will have discovered many new genes that vations provide the evidence that cancer is a genetic disease. This notion seems self-evident today, but it was not generally Table 1 Nonrandom chromosome abnormalities in malignant myeloid diseases accepted several decades ago when many of us began working Disease"CMLCML abnormalityt(9;22)(q34;qll)t(9;22)(q34;ql ofpatients-100-70-2060-100100 in cytogenetics. Clearly, I am using genetic in a special way, referring to changes in genes within the affected cell, not in the more usual sense of a constitutional genetic disease such as blastphaseAML-M2"APL-M3, 1) with +8, +Ph', hemophilia or color blindness. + 19,ori(17q)t(8;21)(q22;q22)t(15;17)(q22;qll-12)inv(16)(pl3q22) Cytogenetic studies of CML2 are important because they provided a number of firsts. The first consistent chromosome M3VAMMoL-M4EoChromosome change in any human cancer was identified in CML by Nowell and Hungerford (15) in 1960 in Philadelphia, thus giving this or t(16;16)(pl3;q22)% morphologically distinct chromosome its special name, Phila (25% of M4) delphia or Ph1 chromosome. Investigation of many patients AMMoL-M4 or M5 t(l;ll)(q21;q23) with CML revealed that marrow cells from the vast majority of t(2;ll)(p21;q23) them had the Ph' chromosome. This cytogenetic analysis be t(6;ll)(q27;q23) t(10;ll)(pll-pl5;q23) -35 came important clinically because, paradoxically, patients ins(10;ll)(pll;q23q24) whose cells were Ph' positive appeared to have a longer survival t(ll;17)(q23;q25) than these whose cells were Ph' negative (16). The reasons for t(Il;19)(q23;P13) t(llql3orq23), del(ll)(q23) this finding will be considered later. In our naive enthusiasm then, we assumed that consistent chromosome changes would AMoL-M5 t(9;l I)(p22;q23), t(l Iql3 or q23) -30 be found in most malignant cells. This hope was quickly dis AML +8 13 pelled in the 1960s before the development of chromosome -7 or del(7q) 9 -5 or del(5q) 6 banding, because some leukemias showed a bewildering array t(6;9)(p23;q34) 2 of chromosome changes whereas others had an apparently t(3;3)(q21;q26) or inv(3)(q21q26) 2 normal karyotype. This variability led to the view I mentioned del(20q) 5 t(12p)ordel(12p) 2 earlier, that chromosome changes were merely epiphenomena. t(3;21)(q26;q22) 1 The situation changed dramatically with the development of chromosome banding in 1970. It became possible to identify Therapy-related AML -7 or del(7q) and/or -5 or del(Sq) 90 each human chromosome, and parts of chromosomes, precisely. l(9;ll)(P22;q23) <1 Thus it became possible to answer a number of questions " AML, acute myeloblastic leukemia; AML-M2, AML with maturation; regarding the Ph' chromosome, namely which small G group AMMoL, acute myelomonocytic leukemia; AMMoL-M4Eo, acute myelomonocytic leukemia with abnormal eosinophils; AMoL, acute monoblastic leukemia; 2The abbreviations used are: CML, chronic myeloid leukemia; ALL, acute APL-M3, M3V, hypergranular (M3) and microgranular (M3V) acute promyelo- lymphoblastic leukemia. cytic leukemia. 3818

Table 2 Cytogenetic-immunophenotypic-genomic correlations in malignant lymphoid diseases Phenotypc Rearrangement Involved genes AcuteleukemiaPre-BB(SIg+)Â°B lymphoblastic

or B-myeloidt(l;19)(q23;pl3)I(8;14)(q24;q32)t(2;8)(pll-12;q24)t(8;22)(q24;qll)t(5;14)(q31;q32)dic(9;!2)(pll;pl2)t(9;22)(q34;qll)I(4;ll)(q21;q23)PRLMYC1GKMYCIL3ABLE2AICHMYCICLICHBCR

Other hyperdiploidy (50-60 chromosomes) del(9p), t(9p) IFNA/B del(12p), t(12p) t(8;l7)(q24;q22) MYC BCL3"

TALI"/TTGC TCRD TCL2' TCRD t(8;14)(q24;qll) MYC TCRA inv(14)(qllq32.3) IGH TCRA inv(14)(qllq32.1)/t(14;14)(qll;q32) TCLÃŒ TCRA t(10;14)(q24;qll) TCL3"-C TCRD t(l;14)(p32;qll) TALl"/SCL TCRD t(7;9)(q35;q32) TCRB t(7;9)(q35;q34) TCRB TCL3" t(7;7)(pl5;qll) TCRG t(7;14)(pl5;qll) TCRG t(7;14)(q35;qll) t(7;19)(q35;pl3) TCRB LYL1 Non-Hodgkin's lymphoma B t(8;14)(q24;q32) MYC IGH t(2;8)(pll-12;q24) IGK MYC t(8;22)(q24;qll) MYC IGL t(14;18)(q32;q21) IGH BCL2 t(ll;14)(ql3;q32) BCLl' IGH see T-cell ALL

Chronic lymphocytic leukemia B t(ll;14)(ql3;q32) BCLl' IGH t(14;19)(q32;ql3) IGH BCL3" t(2;14)(pl3;q32) IGH t(18;22)(q21;qll) BCL2 IGL t(14q32) + 12

t(8;14)(q24;qll) MYC TCRA inv(14)(qll;q32) TCRA TCLl

Multiple myeloma B t(ll;14)(ql3;q32) BCLl IGH t(14q32) IGH

Adult T-cell leukemia t(14;14)(qll;q32) inv(14)(qllq32) +3 Â°SIg, surface immunoglobulin. * Same name used for different translocation breakpoints. c No expressed gene identified at present. d Breakpoint not named; source of translocation for cloning listed. are of critical importance to these cells in their particular stage 1036 (92%) (1). Variant translocations have been discovered, of differentiation. however, in addition to the typical t(9;22). Until recently these Having emphasized the challenge for the future, let me return were thought to be of two kinds: one appeared to be a simple to the success of the present. As noted earlier, the Ph' translo translocation involving No. 22 and some chromosome other cation involved chromosome 9 with a break in the last band in than No. 9 (about 4%); and the other was a complex translo the long arm (9q34) and chromosome 22 with a break in the cation involving three or more different chromosomes, two of long arm, band 22qll. It was clear with banding that a large which were No. 9 and No. 22 (about 4%). Recent data clearly portion of No. 22 was on No. 9 (Fig. 2). Although we assumed demonstrate that No. 9 is affected in the simple as well as the that this was a reciprocal translocation, it was not until 1982 complex translocations and that its involvement had been over that we had proof that this notion was correct (19). Other looked (20). Virtually all chromosomes have been involved in studies with fluorescent markers or chromosome polymor these variant translocation, but No. 17 is affected more often phisms showed that, in a particular patient, the same No. 9 and than are other chromosomes (21). No. 22 were involved in each cell. The karyotypes of many Ph1 In 1972, we lacked the insights and the tools to discern the positive patients with CML have been examined with banding meaning of these translocations. However, the fact that virtually techniques by a number of investigators; in a review of 1129 all of the translocation regularly involved the same two chro Ph' positive patients, the 9;22 translocation was identified in mosomes indicated that two essential genes were involved in 3819

Fig. 2. Karyotype of a CML cell, with chro mosomes stained to show the Giemsa banding If 11 H If fr K I pattern. The material missing from the Ph' chro mosome has been translocated to the end of the second chromosome No. 9, which has additional 9 \ 10 11 12 pale material at the end of the long arm. The two abnormal chromosomes are marked by arrows. tt II H " iÂ» u 13 14 15 16 17 18

â€¢I M Ã¨Ã© * 19 20 2l 22 \ Y the transforming event. The discovery that the Ph1 chromosome man ABL gene was first identified because of its homology to was a translocation led to two questions: (a) was it reciprocal the viral oncogene (\-abl) isolated from a mouse pre-B-cell and (b) what were the genes at the breakpoints? The evidence leukemia. It was shown in 1982 that ABL was located at the that it was a reciprocal translocation was obtained only in 1982 end of chromosome 9 (26). The rapid discovery that ABL was and was directly related to the subsequent cloning of the break translocated to the Ph1 chromosome was the result of the point (19). Our efforts to clone chromosome translocation foresight of Professor Bootsma in Rotterdam and his colleague breakpoints received remarkable assistance from the tumor Geurts van Kessel, who constructed somatic cell hybrids from virologists. These scientists, beginning with Peyton Rous in CML cells and isolated some hybrid cells that contained only 1911, had isolated a number of viruses from spontaneous the Ph' chromosome. Using these hybrids and the probe for cancers and leukemia/lymphomas in various animal species. ABL, it was shown that ABL was translocated to the Ph1 The particular segment of the RNA genome of these viruses chromosome (19). In fact, it was the first gene on chromosome that was associated with its ability to induce transformation 9 that could be shown to be translocated to the Ph' chromo could be isolated with molecular techniques. These segments some, thus providing clear evidence that this was a reciprocal were called oncogenes. It was natural to ask where these onco- translocation. Using the v-abl probe to obtain human ABL genes had come from, but the answer was something of a sequences in 1983, Heisterkamp et al. (27) walked across the surprise. It turned out that they were homologous to highly translocation junction and identified DNA sequences that were conserved genes in normal cells. These cellular counterparts derived from chromosome 22. Using this probe from chromo were referred to as protooncogenes. These conclusions were some 22, they examined DNA from 17 CML patients and based on the research of many scientists who carried out these found that the breakpoints on No. 22 all occurred in a 5.8- studies in the early 1970s. The critical paper that reported these kilobase segment which they called the breakpoint cluster re results has been recognized recently by the selection of J. gion, or ber (28). The gene in which this cluster is located has Michael Bishop and Harold E. Varmus as 1989 recipients of also been cloned and, at least temporarily until its function is the Nobel Prize in Physiology or Medicine (22). The analysis defined, it too is called BCR. As you can imagine, at least in of these viral oncogenes and the protooncogenes has led to an verbal communication, it may be confusing as to whether one increasingly rich understanding regarding the aberrant function is referring to the region ber, written in lower case, or to the of these genes in malignant cells, and in some ways more gene BCR written in capitals and italics. It is a large gene of importantly, their usual function in normal cells as essential 130 kilobases that contains many exons (29). The great majority mediators of cell growth and differentiation (5). of the breakpoints in CML are located in the middle of the Many of us were struck in the early 1980s by the remarkable gene. The breaks usually occur within either of two introns, coincidence of the chromosome location of these protoonco between exons 2 and 3 or between exons 3 and 4 (using the genes and the cancer/leukemia specific breakpoints (23). In original nomenclature of Heisterkamp et al. (29). The exact fact, molecular analysis of the first translocation junction in location can be determined with the use of the polymerase chain 1982 was based, in part, on the use of one of these oncogenes, reaction. There are conflicting data regarding whether the pre namely the MYC protooncogene, the normal human homo cise location of the breakpoint has prognostic significance. logue of the \-myc oncogene from the avian myelocytomatosis Several recent papers suggest that a break between exons 3 and virus, which is located at the breakpoint in Burkitt's lymphoma 4 may be associated with a shorter time before blast transfor (24, 25). The breakpoint junction in CML was the next one to mation (30-32). be cloned and the gene that was the key to cloning the 9;22 In contrast to the breaks in ber, the breaks in ABL on No. 9 translocation was the Abelson (ABL) protooncogene. The hu occur over an incredible distance of more than 200 kilobases, 3820

Downloaded from cancerres.aacrjournals.org on September 27, 2021. © 1990 American Association for Cancer Research. MOLECULAR CYTOGENETICS but again, they always occur in an intron. Pulsed field gel syndrome (35, 36). It is no wonder that they do not have a Ph1 electrophoresis was used by my colleagues, Drs. Charles Rubin chromosome because they do not have CML. But a very inter and Carol Westbrook at the University of Chicago to great esting group of patients, possibly up to 5%, have clinically advantage in the study of the ABL protooncogene. Southern typical CML. Using the ber probe, many of these patients have blotting with standard gel electrophoresis leads to separation the same DNA rearrangements that are identified in the Ph1 of DNA fragments in the size range of 2 to about 25 kilobases. positive CML. Moreover, with special techniques including in Since the ABL gene is larger than 200 kilobases, mapping it in situ chromosome hybridization, the ABL gene can be identified 10- to 20-kilobase pieces is a formidable task. In contrast, by on one of the apparently normal No. 22 chromosomes (37, 38). using pulsed field gel electrophoresis one can separate frag Therefore the ABL gene has been cut out of one No. 9 and ments larger than 1000 kilobases, and this technique is also inserted into a No. 22 adjacent to the BCR gene resulting in very effective in the 100- to 600-kilobase range. As I mentioned the same fusion gene that is present in the typical Ph' chro earlier a normal chromosome band contains roughly 5,000 to mosome. Therefore it seems valid, at present, to consider this 10,000 kilobases and thus, several very large, overlapping frag BCR-ABL fusion gene as the sine qua non of CML. ments could encompass a single band. Using many probes for We faced another dilemma in the study of the Ph' chromo ABL provided by various investigators, Rubin and Westbrook some. I have emphasized the specificity of chromosome trans- in collaboration with Bernards and Baltimore constructed a locations, and yet the Ph1 chromosome appeared to be an partial map of the normal ABL gene (33). exception. As well as its association with CML, an apparently This is a very complex gene that normally uses one of two identical translocation involving chromosomes 9 and 22 was alternative beginnings, exon la or Ib. During transcription, seen in patients with ALL which is a very different disease. The either of these exons can be spliced at the same point to the cloning of the translocation breakpoints in Ph' positive ALL remainder of the gene, which is called the common splice has shed a little light on this confusing issue. acceptor site of exon II. One of their first discoveries was that Ph' positive ALL is common in adults and accounts for at the type Ib exon mapped more than 200 kilobases upstream least 20% of adult ALL patients (39). In fact, this is the single from exon II. Thus, in normal cells, a very large segment of the most frequent abnormality in adult ALL. It has been recognized RNA transcript was removed or spliced out to form the mature for some time that certain chromosome abnormalities have mRNA. This was a remarkable feat, not identified before in prognostic importance. One of the most important of these is biological systems. The sizes of exons la and Ib are different the presence of the Ph1 chromosome which is associated with and therefore the size of the mature mRNA is different. If exon a very poor prognosis in both children and adults. A recent Ib is used, the mRNA is 7.0 kilobases whereas it is 6.0 kilobases prospective study using ber probes and pulsed field gel analysis if exon la is used. In CML, breaks can occur anywhere within indicates that a rearrangement of the BCR gene can be identified the introns of the ABL gene 5' of exon II. As a result of the in 32% of adult ALL patients (40). Earlier analysis of a large translocation, the ABL gene from exon II to its 3' terminus is number of ALL patients showed that about one-half of adults moved next to the midportion of the BCR gene forming a fusion had the CML-type breakpoint in the BCR gene and one-half or chimeric gene (Fig. J>A)(34). In essence, the normal ABL did not (41). In contrast, the data from the molecular study exon la or Ib is replaced by a part of the BCR gene. Despite showed that only 2 of 11 Ph1 positive adult ALL patients had the great variability of the breakpoints in the 5' region oÃABL, a breakpoint in the CML region (40). Although Ph1 positive the same ABL fusion mRNA is formed because the 5' region ALL accounts for only about 5% of childhood ALL, the great of the BCR gene is spliced into the same ABL common splice majority appear to have a non-CML breakpoint. acceptor site of exon II. This fusion mRNA is 8.5 kilobases, A number of investigators have cloned the non-CML break which is much larger than the two normal ABL mRNAs of 6.0 point and have shown that it is 5' of ber, the CML breakpoint, and 7.0 kilobases. and that it is in the first large (70-kilobase) intron of the BCR Cloning the translocation breakpoint has helped to clarify gene (Fig. 3Ã„)(42). Moreover, the breakpoints appear to be several problems. One of these relates to patients discussed clustered in the 3' 20-kilobase segment of this intron (43). The earlier, who appear to have CML, although their leukemic cells breakpoint in ABL is similar to CML, in that it can occur lack the Ph1 chromosome. Many such patients can be shown anywhere in the two introns 5' of exon II. The translocation with careful analysis of the morphology of their bone marrow results in a chimeric BCR-ABL mRNA which is 7.0 kilobases cells not to have CML but to have some other myelodysplastic (Fig. 3B). This is smaller than that seen in CML, because a much smaller portion of the BCR gene is included. In fact, this chimeric message is the same size as one of the two normal ABL mRNAS. This fusion mRNA is translated, in turn, into a fusion or chimeric protein. The normal ABL protein is 145 kDa; its precise function in normal cells is not well understood (Fig. 4). The CML fusion protein is larger, 210 kDa, and it has somewhat increased tyrosine kinase activity (44). The fusion protein seen in some Ph' positive ALL patients is smaller, about 190 kDa (45). The tyrosine kinase activity of this protein is greater than that seen in CML and the increased kinase activity of the BCR-ABL fusion protein in ALL probably leads to a more aggressive leukemia (46). Fortunately, a mouse model Fig. 3. A, map of the BCR-ABL fusion gene in CML and in some adult ALL for CML appears to have been developed recently in which the patients. In this example, the breakpoint has occurred between the third and fourth exons included in the ber region, which are equivalent to exons 11 and 12 myeloid cells express the BCR-ABL 210-kDa fusion protein in the BCR gene. The chimeric mRNA is diagrammed below the gene. B, map of (47). In addition, a transgenic mouse model for Ph' positive the fusion gene in some ALL patients showing the breakpoint in the first intron of BCR. The breakpoint in ABL is identical with that in CML in this example. acute leukemia, either lymphoid or myeloid, has also been Only one BCR exon is included so that the mRNA is much smaller than in CML. developed (48). The BCR-ABL transgene contains only BCR 3821

Normal CML tumors, only the heptamer sequences that are 5' of the other gene, e.g., MYC in the t(8;14)(q24;ql 1) in the SKW3 cell line, have been identified. In other situations there is no evidence that the recombinase system is involved at all (13). However, these aberrant rearrangements would not be seen as a clonal proliferation if they did not provide the involved cells with a selective proliferative advantage vis-Ã -visunaffected cells in the same tissue. Possibly some chromosome rearrangements occur by chance in a cell that has some other genetic change leading to a malignant phenotype. It is difficult to imagine that these chance events would occur repeatedly in a number of independ Fig. 4. Diagram of the Abelson protein in normal cells (left), in cells infected with the abl virus (second), in Ph1 positive ALL (third), and in CML cells (right). ent translocations. However, the recent studies of Tycko et al. In the ALL and CML cells, the protein is larger because some of it is derived (52) show that chimeric rearrangements involving the V and J from the BCR gene and some from the ABL gene. The molecular weight of the segments of the TCRD and TCRG receptors can be detected in protein is given below each one. normal individuals using PCR. These data confirm cytogenetic observations made years before (1975) that translocations in exon 1 and the leukemic cells express the BCR-ABL 190-kDa volving 14ql 1 and either 7pl5 or 7q34-35 are a recurring albeit fusion protein. The mice die of leukemia within the first 2 rare event (10~3 to 10~4/cell) in normal individuals (53-55). months of life. These models will provide the experimental Three groups reported a total of 12 unrelated individuals who systems that are necessary to understand the pathophysiology had a 7; 14 translocation in phytohemagglutinin stimulated of Ph1 positive leukemia. Although we do not yet fully under lymphocyte cultures (53-55). All 12 had a break in 14qll; 6 stand how the different fusion proteins are related to malignant had a 7q34-35 breakpoint, and 6 had a break identified as 7pl3, transformation in either CML or ALL, we at least have the which is more likely to be 7pl5. Thus in these individuals, it tools to ask sensible questions. You can appreciate how complex would appear that there was nonhomologous recombination the study of what appeared to be a simple translocation has involving TCRA and either TCRB or TCRG. These same become. changes occur with much higher frequency in patients with As well as raising a number of questions regarding the func ataxia-telangiectasia (56, 57). tion of the BCR and ABL proteins in normal cells and of the The question related to the interaction of the two genes fusion protein in leukemic cells, cloning the translocation has involved in chromosome translocations can be answered by an provided hematologists and oncologists with an important di analysis of the two different translocations involving the MYC agnostic tool. One can use the DNA probes for the breakpoint protooncogene in B-cell and T-cell tumors. The first translo cluster region and can diagnose CML on the basis of DNA cation, cloned in 1982 independently by Leder and Croce and rearrangements detected with this probe (30-32, 40). With the their colleagues, was the 8; 14 translocation in Burkitt's lym- use of amplification of the translocation junction in both CML phoma which involved the immunoglobulin heavy chain gene and ALL with the polymerase chain reaction (PCR) technique, at 14q32 and MYC at 8q24 (24, 25). Breakpoints in the variant one can monitor the clinical status of patients and can detect Burkitt's translocations involving the immunoglobulin light the very few abnormal cells in early relapse samples (49). chain genes, K at 2pl2 and X at 22ql 1, and MYC were also Moreover, as indicated earlier, it is possible to identify the cloned (58, 59). More recently, we and others have cloned an precise region of the breakpoint in the BCR gene and to analogous translocation in T-cell leukemias (50, 60-62). This correlate this information with a variety of clinical indicators is also an 8; 14 translocation with the break in chromosome 8 to improve our ability to distinguish patients who will not near the MYC gene; the break in No. 14 is in the proximal respond or who will have only a very short response to standard region in band 14ql 1 which is the location of the gene encoding treatment. the a/5 chain of the T-cell receptor (TCRA/TCRD). In this situation, as in the variant Burkitt's translocations, MYC re mains on No. 8 and the J region of TCRA is translocated to Specificity of Translocations the 3' end of the MYC gene and is a variable distance 3' of the Let me return again to the specificity of chromosome trans- 3rd exon of MYC. With very rare exceptions, the MYC-im- locations which is, I believe, a very significant observation munoglobulin rearrangements are seen in B-cell tumors and the despite the quandry posed by the apparent identity of the 9;22 MYC-TCRA rearrangements are seen in T-cell tumors. We translocation in CML and in some Ph1 positive ALL patients. recently described an unusual patient with a B-cell lymphoma, The data obtained from the analysis of the lymphoid leukemias with an 8; 14 translocation involving 14ql 1 and 8q24 in whom and lymphomas have provided insights which I assume will be the breakpoint in chromosome 14 was in the J region of TCRA applicable to the other recurring translocations. The mechanism (63). As far as is known at present, the MYC alterations are or mechanisms by which the specific translocation occur are similar if not identical in both B- and T-cell tumors. Therefore, unknown. Evidence in some lymphoid tumors suggests that the the specificity of the rearrangements is associated with the gene recombinase involved in normal immunoglobulin and T-cell that is specifically active in the particular cell type, clearly receptor gene rearrangements may play a role (13, 50, 51). immunoglobulins in B-cells and T-cell receptor genes in T-cells. Sequencing of the normal homologues of some of the chromo A reasonable paradigm is that translocations bring together, in somes involved in the translocation in both B- and T-cell an aberrant relationship, a gene intimately involved in regulat neoplasms has revealed the presence of the heptamer-nonamer ing growth (a protooncogene in the examples defined to date) sequences that are involved in recombination. This has led to adjacent to an active cell specific gene. The active cell specific the proposal that, in at least some instances, the translocation gene in turn causes the inappropriate expression of the growth has occurred because of an error in the normal gene re regulating gene. arrangement mechanism in lymphoid cells. In some T-cell A number of laboratories are actively investigating the many 3822

Downloaded from cancerres.aacrjournals.org on September 27, 2021. © 1990 American Association for Cancer Research. MOLECULAR CYTOGENETICS factors related to gene expression that interact with each other implications. Within the next decade or two, we should be able as well as with positive and negative regulatory sequences in to define the major genetic abnormalities in many types of the 5' region of genes. Some of the factors that activate genes cancer and to identify the specific changes in the tumor cells of show relatively ubiquitous expression; others have an extremely many patients. For most leukemias, lymphomas, and sarcomas, restricted expression (64). unique chromosome changes often are associated with a partic It has been rather puzzling that some recurring transloca ular subtype of these neoplasms. tions, identified primarily in B-cells, do not appear to involve Cloning of the genes involved in these chromosome changes an expressed gene. The first example of this was the BCL1 will provide specific DNA markers that will have diagnostic putative oncogene identified on chromosome 11 in the 11;14 importance. For some solid tumors, on the other hand, current translocation [t(l I;14)(ql3;q32)] in B-cell chronic lymphatic evidence suggests that deletions of the same chromosome region leukemia (65). Extensive searches for an expressed gene on may occur in different types of tumors, such as the deletions of I Iql3 have been unsuccessful. One possible explanation is that 13q in retinoblastoma, osteosarcoma (not secondary to radia the gene has a very limited range of expression either in a tion for retinoblastoma), breast cancer, and lung cancer. (Re restricted cell type or stage in differentiation. Another expla viewed in Ref. 68.) The deletion of the same region does not nation is related to chromosome structure. Rabbitts and his necessarily imply that the same gene is involved or that the colleagues have recently analyzed a different breakpoint on change within the gene is identical; witness the fact that two I1 p 13, called TCL2 in leukemias with a t( 11;14)(p 13;q 11), and different translocations in band 22ql 1 involve different genes, found that the breaks in all 10 cases occurred within a range of namely, the X light chain gene in the 8;22 translocation in less than 25 kilobases in band Ilpl3 and that 8 of them Burkitt's lymphoma and the BCR gene in CML; furthermore, clustered within 6.7 kilobases (66). DNA sequence analysis of the breakpoints within BCR in Ph1 positive leukemia are also both 1Ipl3 and 1Iql3 breakpoints revealed alternating purine- somewhat variable. pyrimidine sequences suggestive of potential Z-DN A. In 11p 13, The multistep process of malignant transformation is com the purine-pyrimidine region consists of a run of 62 alternating plex. In the leukemias and lymphomas, we often see specific T-G residues; it is 160 base pairs from the breakpoint in one chromosome translocations combined with loss or gain of par tumor cell line and within 900 base pairs in other tumors. The ticular chromosome segments. Some combination of alterations region near the Ilql3 breakpoint seems to be larger and has in dominant!) acting protooncogenes and in recessively acting an unusual repeating series of alternating T-G residues (67). It tumor suppressor genes certainly acts synergistically to enhance is proposed that the location of potential regions of Z-DNA the malignant phenotype. near to translocation breakpoints could make the chromatin In the future, the precise definition of the genetic changes in accessible to site specific recombinases in the absence of tran the malignant cells of a patient will be used to select the most scription of nearby genes. How this rearrangement would pro appropriate treatment for cells with these genetic defects. This vide a growth potential to the affected cell is unclear. treatment will be less toxic for the normal cells in the patient. It should be emphasized that many of the protooncogenes Moreover, this genetic profile may allow monitoring of the were identified in viruses that cause tumors. However, these patient's course and early detection of relapse. These same genes have not been conserved through evolution from yeast genetic markers may be used to detect the involvement of other and Drosophila to the chicken, mouse, and humans to cause tissues such as bone marrow, spleen, or lymph nodes, for cancer. Where we have any insight into the function of these example. These changes in treatment strategies will clearly genes in normal cells, they are growth factors, growth factor benefit the patient. Of more general scientific importance, receptors, or DNA binding proteins. It is not unexpected that however, will be the identification of dozens of genes, many the genes which a virus might coopt if it developed into a tumor hitherto unknown, that can be used to study the complex producing virus would be genes that control proliferation, genes process of the regulation of cell growth and differentiation. This which under viral regulation would function abnormally with development may be the most significant result of our success regard to cell growth. It is unfortunate that these genes were in understanding the genetic changes that occur in cancer cells. first identified because their mutant forms were associated with I would like to conclude with a more personal note based on cancer. The term "oncogene" is too short and easy for it to be my continuing amazement at the interrelatedness of the discarded, but it really refers to respectable genes for regulating biomÃ©dicalsciences. This should be no surprise to me, but it is. cell growth. Many investigators have found that a successful system for Up to now, I have extolled the importance of chromosome carrying out some function in primitive organisms has evolved aberrations as powerful tools to locate genes that are central to and then this system is used repeatedly with varying modifica the process of malignant transformation. Although I have con tions as the organisms become more complex. As a cytogene- centrated on hematological malignant diseases, it is clear from ticist, I had to learn something about the cell cycle and DNA the remarkable progress that has been made in cloning genes replication, about chromosome structure, and about various in solid tumors, both the RBI gene in retinoblastoma and a agents that can alter both of these. More recently, I have had series of genes in colon cancer, that knowing the location of to become an amateur tumor virologist at least with regard to cytogenetic abnormalities has been central to this progress. the action of viral oncogenes and their cellular counterparts, I will conclude with some comments regarding the longer- the protooncogenes. With the cloning of translocations, espe term potential impact of discovering new genes via chromosome cially some of the recent ones, a knowledgeable cancer cytoge- rearrangements. Once these genes are identified, many previ neticist must understand cell cycle control genes in yeast (cdclO ously unknown, BCR, e.g., they become the focus of very active and SW14 and 6) and developmentally regulated genes in Dro investigation. Scientists try to find answers regarding the func sophila (Notch for example) and nematodes (lin 10, gip 1). My tion of these genes in normal cells; how are they altered by the colleague, Timothy McKeithan, has recently cloned the BCL3 chromosome rearrangements, and how does this relate to ma gene that is involved in the 14; 19 translocation in B-cell leu lignant transformation? The questions are endless. The answers kemias (69). If I am to understand the possible roles this gene will provide insights into cell biology that have very profound plays in B-cell transformation, I must understand how its 3823

Downloaded from cancerres.aacrjournals.org on September 27, 2021. © 1990 American Association for Cancer Research. MOLECULAR CYTOGENETICS homology to portions of the cdclO and Notch genes might 24. Dalla-Favera, R., Bregni, M., Erikson, J., Patterson, D., Gallo, R. C., and Croce, C. M. Human c-myc one gene is located on the region of chromosome provides clues as to its functions in both normal and malignant 8 that is translocated in Burkitt lymphoma cells. Proc. Nati. Acad. Sci. USA, cells. As more genes involved in translocations and deletions 79:7824-7827, 1982. are defined, many of us in cancer research will continue to have 25. Taub, R., Kirsch, I., Morton, C., Lenoir, G., Swam. D., Aaronson, S., and to "go back to school" to be able to incorporate the knowledge Leder, P. Translocation of the c-myc gene into the immunoglobulin heavy chain locus in human Burkitt lymphoma and murine plasmacytoma cells. provided by molecular geneticists and cell biologists into our Proc. Nati. Acad. Sci. USA, 79: 7837-7841, 1982. concepts of carcinogenesis. The golden ages in biology and in 26. Heisterkamp, N., Groffen, J., Stephenson, J. R., Spurr, N. K., Goodfellow, P. N., Solomon, E. Carril, B., and Bodmer, W. F. Chromosomal localization medicine are nourishing one another as never before in history. of human cellular homologues of two viral oncogenes. Nature (Lond.), 299: 747-749, 1982. 27. Heisterkamp, N., Stephenson, J. R.. Groffen, J., Hansen. P. F., de Klein, A., Acknowledgments Bartram, C. R., and Grosveld, G. Localization of the c-abl oncogene adjacent to a translocation breakpoint in chronic myelocytic leukemia. Nature (Lond.). My colleagues, Drs. Manual Diaz, Michelle Le Beau, and Timothy 306: 239-242. 1983. McKeithan, have been generous with their review of the manuscript 28. Groffen, J., Stevenson, J. R., Heisterkamp, N., de Klein, A., Bartram, C. R., and Grosveld, G. Philadelphia chromosomal breakpoints are clustered within and with advice on the construction of Fig. 1. I acknowledge the expert a limited region, her, on chromosome 22. Cell, 36: 93-99, 1984. secretarial assistance of Felecia Stokes. 29. Heisterkamp, N.. Stam, K., Groffen. J., de Klein, A., and Grosveld, G. Structural organization of the ber gene and its role in the Ph1 translocation. Nature (Lond.), 315: 758-761, 1985. References 30. Shtalrid, M., Talpaz, M., Kurzrock, R., Kantarjian, H., Trujillo, J., Gutter- man, J., Yoffe, G., and Blick, M. Analysis of ber gene and correlation with 1. Rowley, J. D. Principles of molecular cell biology of cancer: chromosomal clinical course in Ph-positive chronic myelogenous leukemia. Blood, 72:485- abnormalities. In: V. T. de Vita, S. Hellman, and S. A. Rosenberg (eds.), 491, 1988. Cancer: Principles and Practice of Oncology, Ed. 3, pp. 81-97. Philadelphia: 31. Mills, K. I., MacKenzie, E. D., and Bernie, G. D. The site of the breakpoint J. B. Lippincott Co. within the ber is a prognostic factor in Philadelphia-positive CML patients. 2. Heim, S., and Mitelman, F. Cancer Cytogenetics. New York: Alan R. Liss, Blood. 72: 1237-1241, 1988. Inc., 1987. 32. Grossman, A., Silver, R. T., Arlin, Z.. Coleman, M., Camposano, E., Gascon, 3. Mitelman, F. Catalog of Chromosome Aberrations in Cancer. New York: P., and Benn, P. A. Fine mapping of chromosome 22 breakpoints within the Alan R. Liss. Inc., 1988. breakpoint cluster region (ber) implies a role for her exon 3 in determining 4. Trent, J. M., Kaneko, Y., and Mitelman, F. Human Gene mapping 10: report disease duration in chronic myeloid leukemia. Am. J. Hum. Genet., 45:729- of the committee on structural chromosome changes in neoplasia. Cytogenet. 738, 1989. Cell Genet., 51: 533-562, 1989. 33. Bernards, A., Rubin, C. M., Westbrook, C. A., Paskind, M., and Baltimore, 5. Bishop, J. M. The molecular genetics of cancer. Science (Wash. DC), 235: D. The first intron in the human c-abl gene is at least 200 kilobases long and 305-311, 1987. is a target for translocations in chronic myelogenous leukemia. Mol. Cell. 6. Rowley, J. D. A new consistent chromosomal abnormality in chronic mye- Biol., 7:3231-3236, 1987. logenous leukemia identified by quinicrine fluorescence and Giemsa staining. 34. Shtivelman, E., Lifshitz, B., Gale, R. P., Roc, B. A., and Canaani, E. Nature (Lond.), 243: 290-293, 1973. Alternative splicing of RNAs transcribed from the human abl gene and from 7. Francke, U. Retinoblastoma and chromosome 13. Cytogenet. Cell Genet., the bcr-abl fused gene. Cell, 47: 277-284, 1986. 16: 131-134, 1976. 35. Pugh, W. C., Pearson, M., Vardiman, J. W., and Rowley. J. D. Philadelphia 8. Friend, S. H., Bernards, R., Rogel, S. et al. A human DNA segment with chromosome-negative chronic myelogenous leukemia: a morphologic reas properties of the gene that predisposes to retinoblastoma. Nature (Lond.), sessment. Br. J. Haematol., 60: 457-467, 1985. 323: 643-646, 1986. 36. Travis, L. B., Pierre, R. V., and DeWald, G. W. Ph1 negative chronic 9. Fearon, E. R., Cho, K. R., Nigro, J. M., Kearn, S. E., Simons, J. W., Ruppert, granulocytic leukemia: a nonentity. Am. J. Clin. Pathol., 85: 186-193, 1986. J. M.. Hamilton, S. R., Preisinger, A. L., Thomas. G., Kinzler, K. W., and 37. Morris, C. M., Reeve, A. E., Fitzgerald, P. H., Hollings. P. E., Beard, M. E. Vogelstein, B. Identification of a chromosome 18q gene that is altered in J., and Heaton, D. C. Genomic diversity correlates with clinical variation in colorectal cancers. Science (Wash. DC), 247:49-56, 1990. Ph'-negative chronic myeloid leukemia. Nature (Lond.), 320: 281-283,1986. 10. Mullens, M., Salmon, R. J., Zafrani, B., Girodet, J., and Dutrillaux, B. 38. Shtalrid. M., Talpaz, M., Blick, M.. Romero. P., Kantarjian, H., Taylor, K., Consistent deficiencies of chromosome 18 and of the short arm of chromo Trujillo, J., Schachner, J., Gutterman, J. U., and Kurzrock, R. Philadelphia- some 17 in eleven cases of human large bowel cancer: a possible recessive determinism. Ann. Genet., 28: 206-213, 1985. negative chronic myelogenous leukemia with breakpoint cluster region re arrangement: molecular analysis, clinical characteristics and response to 11. Leder, P., Battey, J., Lenoir, G., Moulding, C., Murphy, W., Potter, H., therapy. J. Clin. Oncol., 6: 1569-1575, 1988. Stewart, T., and Taub, R. Translocations among antibody genes in human cancer. Science (Wash. DC), 222: 765-771, 1983. 39. The Third International Workshop on Chromosomes in Leukemia. Cancer Genet. Cytogenet., 4: 95-142, 1981. 12. Croce, C. M., and Nowell, P. C. Molecular genetics of human B cell neoplasia. 40. Hooberman, A. L., Westbrook, C. A., Davey, F., Schiffer, C., Spino, L., and Adv. Immunol., 38: 245-274, 1986. Bloomfield, C. D. Molecular detection of the Philadelphia (Ph') chromosome 13. Rabbitts, T. H., Boehm, T., and Mengle-Gaw, L. Chromosomal abnormali in acute lymphoblastic leukemia (ALL): clinical, cytogenetic. and immunÂ» ties in lymphoid tumours; mechanisms and role in tumour pathogenesis. Trends Genet., 4: 300-304, 1988. phenotypic correlations in a CALGB study. Blood, 72: 52a, 1989. 41. Chen, S. J.. Flandrin, G., Daniel, M-T., Valensi, F.. Baranger, L., Grausz, 14. Yunis, J. J., Bloomfield, C. D., and Ensrud, K. All patients with acute D.. Bernheim, A., Chen. Z., Sigaux, F., and Berger, R. Philadelphia-positive nonlymphocytic leukemia may have a chromosomal defect. N. Engl. J. Med., 305: 135-139, 1981. acute leukemia: lineage promiscuity and inconsistently rearranged breakpoint cluster region. Leukemia (Baltimore), 2: 261-273, 1988. 15. Nowell, P. C., and Hungerford, D. A. A minute chromosome in human granulocytic leukemia. Science (Wash. DC), 132: 1497, 1960. 42. Hermans, A., Heisterkamp, N., von Lindern, M., van Baals, Meijer, D., 16. Whang-Peng, J., Canellos, G. P., Carbone, P. P., and Tjio, J. Clinical van der PÃas,D., Wiedermann, L. M., Groffen, J., Bootsma, D., and Gros veld, G. Unique fusion of the ber and c-abl genes in Philadelphia chromosome implications of cytogenetic variants in chronic myelocytic leukemia (CML). Blood, 32: 755-766, 1968. positive acute lymphoblastic leukemia. Cell. 51: 33-40, 1987. 17. Rowley, J. D. Identification of a translocation with quinacrine fluorescence 43. Denny, C. T.. Shah, N. P., Ogden, S., Willman, C., McConnell, T., Crist, in a patient with acute leukemia. Ann. Genet.. 16: 109-112, 1973. W., Carroll, A., and Witte, O. N. Localization of preferential sites of rearrangement within the BCR gene in Philadelphia chromosome-positive 18. Rowley, J. D. Mapping of human chromosomal regions related to neoplasia: acute lymphoblastic leukemia. Proc. Nati. Acad. Sci. USA, 86: 4254-4258, Evidence from chromosomes No. 1 and 17. Proc. Nati. Acad. Sci. USA, 74: 5729-5733, 1977. 1989. 19. Hagemeijer, A. Bootsma, D., Spurr, N. K., Heisterkamp, N., Groffen, J., 44. Konopka, J. B.. Watanabe, S. M., and Witte, O. N. An alteration of the and Stevenson, J. R. A cellular oncogene is translocated to the Philadelphia human c-abl protein in K562 leukemia cells unmasked associate tyrosine chromosome in chronic myelocytic leukemia. Nature (Lond.), 300:765-767, kinase activity. Cell, 37: 1035-1042. 1984. 1982. 45. Chan, L. C., Karhi, K. K., Rayter, S. I., Heisterkamp, N., Eridani, S., Powles, 20. de Klein, A. Hagemeijer, A. Cytogenetic and molecular analysis of the Ph1 R., Lawler, S. D., Groffen, J., Foulkes, J. G.. Greaves, M. F., and Wiede- translocation in chronic myeloid leukemia. Cancer Sun., 3: 515-529, 1984. mann. L. M. A novel abl protein expressed in Philadelphia chromosome 21. Rowley. J. D. The Philadelphia chromosome translocation. In: J. M. Gold positive acute lymphoblastic leukemia. Nature (Lond.), 325: 635-637. 1987. man and D. G. Harnden (eds.). Genetic Rearrangements in Leukemia and 46. Lugo, T. G., Pendergast, A-M., Muller, A. J., and Witte, O. N. Tyrosine Lymphoma, Vol. 2, pp. 82-99. Edinburgh: Churchill Livingstone, 1986. kinase activity and transformation potency of bcr-abl oncogene products. 22. Stehelin, D., Bishop, J. M., Varmus, H. E., Vogt, P. DNA related to the Science (Wash. DC), 247: 1079-1082, 1990. transforming gene(s) of avian sarcoma viruses is present in normal avian 47. Daley. G. Q.. Van Etten. R. A., and Baltimore, D. Induction of chronic DNA. Nature (Lond.). 260: 170-173, 1976. myelogenous leukemia in mice by the P210 ftcr/ae/gene of the Philadelphia 23. Rowley, J. D. Human oncogene locations and chromosome aberrations chromosome. Science (Wash. DC), 247: 824-830. 1990. (News and Views). Nature (Lond.), 301: 290-291. 1983. 48. Heisterkamp, N. N.. Jenster, G., ten Hoeve, J., Zovich. D.. Pottengale, P. 3824

K, and Groffen, J. Acute leukemic in bcr/abl transgenic mice. Nature (Lond.), 60. Shima, E. A., Le Beau, M. M., McKeithan, T. W., Minowada, J., Showe, L. 3^:251-253, 1990. C., Mak, T. W., Minden. M. D., Rowley, J. D., and Diaz, M. O. Gene 49. Hooberman, A. L., Carrino, J. J., Leibowitz, D., Rowley, J. D., Le Beau, M. encoding the a chain of the T-cell receptor is moved immediately downstream M.. Arlin, Z. A., and Westbrook, C. A. Unexpected heterogeneity of BCR- of c-myc in a chromosomal 8;14 translocation in a cell line from a human T- ABL fusion mRNA detected by polymerase chain reaction in Philadelphia cell leukemia. Proc. Nati. Acad. Sci. USA, 83: 3439-3443, 1986. chromosome-positive acute lymphoblastic leukemia. Proc. Nati. Acad. Sci. 61. McKeithan, T. W., Shima, E. A., Le Beau. M. M., Minowada, J., Rowley, USA, 86: 4259-4263, 1989. J. D., and Diaz, M. O. Molecular cloning of the breakpoint junction of a 50. Finger, L. R., Harvey, R. C., Moore, R. C. A., Showe, L. C., and Croce, C. human chromosomal 8; 14 translocation involving the T-cell receptor Â«-chain M. A common mechanism of chromosomal translocation in T- and B-cell gene and sequences on the 3' side of c-myc. Proc. Nati. Acad. Sci. USA, 83: neoplasia. Science (Wash. DC), 234: 982-985, 1986. 6636-6640, 1986. 51. Tycko, B., and Sklar, J. Chromosomal translocations in lymphoid neoplasia: 62. Mathieu-Mahul, D., Caubet, J. F., and Bernheim, A. Molecular cloning of a a reappraisal of the recombinase model. Cancer Cells, 2: 1-8. 1990. DNA fragment from human chromosome 14(14qll) involved in T cell 52. Tycko, B., Palmer, J. D., and Sklar, J. T cell receptor gene trans-re malignancies. EMBO J., 4: 3427-3433, 1985. arrangements: chimeric â€”5genes normal lymphoid tissues. Science (Wash. 63. Park, J. K., McKeithan. T. W.. Le Beau, M. M., Bitter, M. A., Franklin, W. A., Rowley, J. D., and Diaz, M. O. An (8;14)(q24;ql 1) translocation involv DC), 245: 1242-1246, 1989. ing the T-cell receptor o-chain and the MYC oncogene 3' region in a B-cell 53. Welch, J. P., and Lee, C. L. Y. Nonrandom occurrence of 7-14 translocations in human lymphocyte cultures. Nature (Lond.), 255: 241-242, 1975. lymphoma. Genes Chromosomes Cancer, 1: 15-22, 1989. 54. Beatty-DeSana, J. W., Hoggard, M. J., and Colledge, J. W. Nonrandom 64. Augereau, P., and ChambÃ³n, P. The mouse immunoglobulin heavy-chain occurrence of 7-14 translocations in human lymphocyte cultures. Nature enhancer: effect on transcription in vitro and binding of proteins present in HeLa and lymphoid B cell extracts. EMBO J., 5: 1791-1797, 1986. (Lond.), 255:242-243, 1975. 55. Hecht, F., Kaiser-McCaw, B., Peakman, D., and Robinson, A. Nonrandom 65. Tsujimoto, Y. E., Jaffe, E., Cossman, J., Gorham, J., Nowell, P. C., and Croce, C. M. Clustering of breakpoints on chromosome 11 in human B-cell occurrence of 7-14 translocations in human lymphocyte cultures. Nature neoplasms with the t( 11;14) chromosome translocation. Nature (Lond.), 315: (Lond.), 255: 243-244, 1975. 340-343, 1985. 56. Kaiser-McCaw, B., Hecht, F., Harnden. D. G., and Teplitz, R. Somatic 66. Foroni, L., Boehm, T., Lampert, F., Kaneko, Y., Raimondi, S., and Rabbitts, rearrangement of chromosome 14 in human lymphocytes. Proc. Nati. Acad. T. H. Multiple methylation-free islands flank a small breakpoint cluster Sci. USA, 72:2071-2075, 1975. 57. Aurias, A. Analyse cytogenetique de 21 cas d'ataxie-telangiectase. J. Genet. region on 11p 13 in the t( 11;14)(p 13;q 11) translocation. Genes Chromosomes Cancer, /: 301-309, 1990. Hum., 29: 235-247, 1981. 67. Boehm, T., Mengle-Gaw, L., Kees, U. R., Spurr, N. Lavenir, L, Forster, A., 58. Adams, J., Gerondakis, S., Webb, E., Corcoran, L. M., and Cory, S. Cellular and Rabbitts, T. H. Alternating purine-pyrimidine tracts may promote chro myc oncogene is altered by chromosome translocation to an immunoglobulin mosomal translocations seen in a variety of human lymphoid tumors. EMBO locus in murine plasmacytomas and is rearranged similarly in human Burkitt J., Â«.-2621-2631, 1989. lymphomas. Proc. Nati. Acad. Sci. USA, 80: 1982-1986, 1983. 68. Sager, R. Tumor suppressor genes: the puzzle and the promise. Science 59. Croce, C. M., Thierfelder, W., Erikson. J., Nishikura, K., Finan, J., Lenoir, (Wash. DC), 246: 1406-1412, 1989. G. M., and Nowell, P. C. Transcriptional activation of an unrearranged and 69. Ohno, H., Takimoto, G., and McKeithan, T. W. The candidate proto untranslocated c-myc oncogene by translocation of a C locus in Burkitt oncogene bcl-3 is related to genes implicated in cell lineage determination lymphoma cells. Proc. Nati. Acad. Sci. USA, 80: 6922-6926, 1983. and cell cycle control. Cell, 60: 991-997, 1990.

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Janet D. Rowley

Cancer Res 1990;50:3816-3825.

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