Cancer Chemother Pharmacol #2001) 47 #Suppl): S16±S22 Ó Springer-Verlag 2001 ORIGINAL ARTICLE Martin Wald á Toma sÏ Oleja r á Veronika SÏ ebkova Marie Zadinova á Michal Boubelõ k á Pavla PoucÏ kova Mixture of trypsin, chymotrypsin and papain reduces formation of metastases and extends survival time of C57Bl6 mice with syngeneic melanoma B16 Abstract Purpose: The aim of the present study was to decreased expression of CD44 and CD54 molecules in investigate the eect of a mixture of proteolytic enzymes tumors exposed to proteolytic enzymes in vivo. #comprising trypsin, chymotrypsin and papain) on the Conclusions: Our data suggest that serine and cysteine metastatic model of syngeneic melanoma B16. Methods: proteinases suppress B16 melanoma, and restrict its 140 C57Bl6 mice were divided into two control and two metastatic dissemination in C57Bl6 mice. ``treated'' groups. Control groups received saline rectally, twice a day starting 24 h after intracutaneous Key words Trypsin á Papain á B16 melanoma á transplantation #C1) or from the time point of the Metastasis primary B16 melanoma extirpation #C2), respectively. ``Treated'' groups were rectally administered a mixture of 0.2 mg trypsin, 0.5 mg papain, and 0.2 mg chymo- Introduction trypsin twice daily starting 24 h after transplantation #E1) or after extirpation of the tumor #E2), respectively. Lack of requisite immune surveillance in tissue dier- Survival of mice and B16 melanoma generalization were entiation is an important mechanism that gives rise to a observed for a period of 100 days. Immunological clone of malignant cells, which eventuates in tumori- evaluation of B16 melanoma cells in the ascites was genesis. Thus, a hallmark of malignant tumors is accomplished. CD44, CD54 and CD106 cells were uncontrolled, invasive growth and its spread. Tumors measured by ¯ow cytometry. Results: Administration of metastasize when targeted surgical intervention or sys- proteolytic enzymes to mice inhibited the growth of temic cytostatic treatments are unsuccessful. The prev- primary tumors, and tumor recurrences were less alence of remote metastases is largely determined by the numerous. Importantly, metastasis was considerably type of primary malignancy; the tissue#s) of its origin, curtailed both in the vicinity of the primary tumor and such as lymph nodes, lung, liver, brain and bone mar- at distant locales. These ®ndings correlated with a row, etc., are central to metastatic growth. For example, CD44 plays a contributory role in the progression of tumors, being crucial in adhesion and motility; it putatively activates genes necessary for invasion and Work presented at ECCO 10, The European Cancer Conference, metastasis [15, 30±32, 35]. Vienna, 12±16 September 1999 Ideally, a biological response modi®er regimen is directed toward strengthening the defense response with M. Wald #&) Department of Surgery, 2nd Medical School, a concomitant goal of suppressing tumorigenesis. Serine Charles University, Vu valu 84, and cysteine proteases from both animal and plant 150 00 Prague 5, Czech Republic sources have been shown to modulate immune response Tel.: +420-2-2443417; Fax: +420-2-24434120 in several systems [20, 40]. Thus, enzymatic, radiochro- e-mail: [email protected] matographic and immunological techniques underscore T. Oleja r á M. Zadinova á V. SÏ ebkova á P. PoucÏ kova the fact that upon oral and rectal administration, Institute of Biophysics, enzymes are absorbed intact, and, therefore, are assim- Charles University, Prague, Czech Republic ilated in their biologically active form [2, 9, 22]. After absorption, proteases are bound to circulating M. Boubelõ k Institute of Molecular Genetics, anti-proteases, such as a2-macroglobulin and a1-prote- Czech Academy of Sciences, ase inhibitor, leading to a dynamic equilibrium between Prague, Czech Republic the free and bound molecules in the bloodstream. The S17 proteases maintain their hydrolytic activity upon In the control group #C1), 0.1 ml saline was rectally adminis- complexing with a2-macroglobulin; likewise, after tered to 20 mice twice a day starting 24 h after intracutaneous transplantation, until the termination of the study #100 days). In binding to sundry other circulating anti-proteases, they the ``treated'' group #E1), a mixture #0.1 ml) of 0.2 mg trypsin, have the ability to modulate the cytokine network [13, 0.5 mg papain and 0.2 mg chymotrypsin was rectally administered 17, 24, 25]. to 50 mice twice daily starting 24 h after transplantation, and was It is known that bromelain, papain and amylase, continued throughout the duration of the study. This regimen which are generic proteases, induce cytokine production amounted to 0.9 mg of enzyme mixture per 20 g of body weight. This dose, in turn, corresponded to 45 mg/kg of the composite in vitro in peripheral blood mononuclear cells [4]. In- enzyme preparation Wobe-Mugos E #MUCOS Pharma, Germany). gestion of multienzyme mixtures, comprising bromelain, The enzyme mixture was prepared freshly before each adminis- trypsin, chymotrypsin and papain, induce mononuclear tration. cells to express, de novo, tumor necrosis factor alpha In the control group #C2), again, saline #0.1 ml) was adminis- tered rectally to 20 mice twice daily from the time point of extir- #TNF-a), interleukin-1b #IL-1b), and interleukin-6 pation of the primary B16 melanoma, and continued for the #IL-6) when incubated exvivo with interferon-gamma duration of the study #100 days). A total of 50 mice pooled in a #IFN-c) [5, 6]. It has also been reported that proteases ``treated'' group #E2) were rectally administered 0.2 mg trypsin, induce a respiratory burst in granulocytes with con- 0.5 mg papain and 0.2 mg chymotrypsin #in 0.1 ml) after extirpa- tion of the tumor, and the regimen continued for the duration of comitant production of reactive oxygen species. Addi- the study. tionally, proteases are known to induce cytotoxicity in peripheral neutrophils in vitro [49]. All the same, evidence suggests that proteases inhibit Eect of enzymes on adhesion molecules tumors. For instance, peripheral lymphocytes, when in- Immunological evaluation of B16 melanoma cells in the ascites was cubated with trypsin in vitro, show a selective decrease accomplished in two groups, each comprising of sixanimals as in the density of CD4, CD44 and CD80 [26, 36]. outlined above. Mice in the control group #C3) received saline Bromelain and trypsin, either alone or in combination, rectally from the time of B16 transplantation in the abdominal cavity, twice daily for a period of 7 days, whereas the ``treated'' decrease the expression of CD44 in SMMU-2 and group #E3) received enzyme mixture in exactly the same ratios as SK-MEL 28 melanoma, MOLT 4/8, leukemia cell line, described above. After 7 days, ascites cells were harvested from and those of mammary carcinomas [12, 14, 34]. each group of animals by lavage. Moreover, the density of adhesion molecules in lung metastases were determined in each group #C1, E1, C2, E2). Depending upon the time of sampling, metastasized and abdominal ascitic cells were homogenized in glutamine-sup- Materials and methods plemented RPMI medium, and the cell numbers determined ac- cording to Turk. Cells were diluted to the 2 ´ 106 cells/ml. The Animals suspension was washed twice with PBS, and 2 ll of antibodies speci®c to the adhesion molecules were added #CD44, CD54, CD106, ¯uorescein for negative control) #Pharmingen, San Diego, A total of 148 female inbred C57Bl6 mice #average body weight: 18± 20 g) were used #AnLab, Charles River, Czech Republic) in this California). The mixture was incubated on ice for 30 min, washed study. The animal colony was maintained in a barrier facility with three times with 1±2 ml PBS with a tissue medium, centrifuged at sterilized bedding #SAW1 Research Bedding), and fed radia- 1,000 rpm for 10 min at 4 °C, supernatant was removed and the tion-sterilized diet ST-1 #Bergmann) with sterile water supplied precipitate was gently agitated. Tumor cells with bound antibody ad libitum. were measured on a Becton-Dickinson FACS analyzer. Autopsy and histological observation Tumor cells The progression of tumorigenesis was monitored in each group for B16 tumor cells were grown in the abdominal cavity of inbred mice. 6 a period of 100 days, at which point all surviving animals were On day 10 after intraperitoneal transplantation of 2 ´ 10 tumor killed, and the tissue sectioned from lungs, liver and any recurring cells, ascites were harvested and adjusted to a concentration of 6 primary tumors and metastases in axillary lymph nodes was his- 4 ´ 10 cells/0.2 ml of suspension. This suspension was injected tologically examined. The tissue sections were ®xed with formalin individually into a total of 140 C57Bl6 mice intracutaneously, and and stained with hematoxilin-eosin #HE) by the usual procedure. in vivo incubation allowed to proceed for 10 days, at which time The lung tissue was embedded in toto, and transversally sectioned growing tumors were excised. up to the heart ventricles. Tumor growth Statistical analyses Ten days after transplantation, the growing tumors were extirpat- The Gehan-Wilcoxon test was used for statistical analysis of the 2 ed, and the tumor volume measured according to V 1/2 á A á B , survival data. Volumes of primary tumors were statistically where A denotes the largest dimension of the tumor mass and B evaluated by the analysis of variants. stands for the smallest dimension [16]. Malignance in the tumor mass was ascertained histologically. Results