SUPPLEMENTAL INFORMATION

SLC45A3-ELK4 is a Novel and Frequent ETS Fusion Transcript in Prostate Cancer

David S. Rickman1, Dorothee Pflueger1, Benjamin Moss1, Vanessa E. VanDoren1, Chen X. Chen1, Alexandre de la Taille2,3, Rainer Kuefer4, Ashutosh K. Tewari5, Sunita R. Setlur6 Francesca Demichelis1,7 and Mark A. Rubin1

1Department of Pathology & Laboratory Medicine, Weill Cornell Medical Center, New York, NY 10065, USA. 2Department of Urology, CHU Mondor, Créteil, France 3INSERM, Unité 841, Créteil, France 4Department of Urology, University Hospital Ulm, Ulm, Germany 5Department of Urology, Weill Cornell Medical College, New York, NY 10065, USA 6Department of Pathology Brigham and Women’s Hospital, Boston, MA; Harvard Medical School, Boston, MA 02115, USA 7Institute for Computational Biomedicine, Weill Cornell Medical Center, New York, NY 10065, USA.

Supplemental Materials and Methods

Sample processing and RNA extraction. Hematoxylin and eosin (H&E) slides were

evaluated for cancer extent and tumor grade (Gleason Score). Areas with high-density

cancer foci (< 10% stromal and other non-tumor tissue contamination) were cored using a

1.5 mm dermatome from the corresponding frozen tissue block. RNA was isolated using

TRIzol® Reagent (Invitrogen, Carlsbad, CA) according to the manufacturer’s

instructions. After purification, we measured the quality of RNA using the Bioanalyzer

2100 (Agilent Technologies Inc., Santa Clara, CA). RNA was then subjected to DNase

treatment (Invitrogen) and quantified using a NanoDrop 8000 spectrophotometer

(Thermo Scientific, Wilmington, DE). Cell lines were obtained from American Type

Culture Collection (ATCC®, Manassas, VA). Cells were maintained according to the

supplier’s instructions.

Quantitative RT-PCR using Taqman technology. To quantify SLC45A3-ELK4 and

endogenous ELK4 transcripts we employed custom designed (SLC45A3-ELK4: primers

in SLC45A3 exon 1 and ELK4 exon 2, probe in ELK4 exon2) and inventoried (ELK4,

Hs00360812_m1) TaqMan Expression Assays using the ABI 7500 Fast Real-Time

PCR System (Applied Biosystems, Foster City, CA) following the manufacturer’s RNA-

to-CT™ 1-step protocol. Each target was run in triplicate and expression levels were

normalized using TCFL1 as and calibrated to the median expression levels of benign

samples. For the analyses on RNA extracted from urine raw values for SLC45A3-ELK

were normalized to the control gene TCFL1 and then calibrated to 1 of the cases yielding

negative cancer results on biopsy material.

Conventional RT-PCR Sequencing. The qualitative detection of SLC45A3-ELK4

transcripts was performed using Platinum Taq DNA Polymerase kit (Invitrogen) and 50 ng of cDNA as template in a final volume of 25 ml. The PCR was run using a forward

primer in SLC45A3 exon 1 (5-CCGCGGAGTAACCTGGAGATTT-3) and reverse

primer in ELK4 exon 2 (5-TGCCCATCATTAGAGGTCCAACAG-3). DNA fragments

corresponding to the expected sizes of fusion transcripts were sequenced at the Life

Sciences Core Laboratories Center's DNA sequencing facility of Cornell University

(Ithaca, NY).

Chromosome 1q32, SLC45A3 to ELK4 region assessment. To assess the DNA copy

number status of the of 1 region separating SLC45A3 and ELK4, we designed primers targeted against repeat-masked genomic DNA to be used in a quantitative PCR (Q-PCR) assay that target 13 100-200 bp segments between the last exon of SLC45A3 and the first exon of ELK4, see below for primer information).

Quantitation was performed using Q-PCR by relative standard curve method. Primers targeting a copy number stable chromosomal region in ARHGEF (chr1:155205397-

155205600) were used for normalization (FWD: 5’ TCTCTGCTCCCTCACTCTCAA 3’,

REV: 5’TGTGCCTCTTCCATCGTTCT3’). DNA from Hapmap sample NA12155 at 5 concentrations (0.5 ng – 50ng) was run for each of the 13 primer pairs to generate the standard curve per primer pair and per 384-well plate. All reactions were run in triplicates.

Hormonal treatment of LNCaP. The prostate cancer cell line LNCaP was obtained from ATCC (Manassas, VA; cat.# CRL-1740) and maintained according to the suppliers instructions. For hormonal treatment, cells were plated (500,000 cells/10 cm2) in the presence of complete growth medium supplemented with 1% Penicillin/Streptomycin.

Cells were starved for 48h in charcoal-stripped (CS) medium (RPMI-1640 1x, 5% CS-

FBS, 1% Penicillin/Streptomycin) and then treated with R1881 (1nM) or vehicle for 3h,

12h and 24h. RNA was extracted using the TRIzol Reagent (Invitrogen, Carlsbad, CA), subjected to DNase treatment (DNA-freeTM Kit, Applied Biosystems) according to the manufacturers instructions and used in quantitative RT-PCR with ETV1

(Hs00951947_m1) as an androgen read-out gene, specific to this cell line. To test for the specificity of androgen-stimulation cells were treated with 10um Flutamide for 48 hours and then treated with R1881 as described above.

Supplemental Figure Legends

Supplemental Figure 1. Conventional PCR results.

Using primers indicated in Figure 1C RT-PCR was performed on total RNA

extracted from 35 prostate cancer samples, 6 benign samples, 6 prostate cancer cell

lines (NCI-H660, VCaP, PC3, LNCaP, DU145, 22-RV1) and 1 benign cell line

(RWPE-1). This gel representative bands from 13 prostate cancer samples (PCa) and

NCI-H660, VCaP, PC3, LNCaP and RWPE-1 cells and 6 benign prostate tissue

(below). While we demonstrated SLC45A3-ELK4 mRNA signal in all of these samples by Taqman (Figure 1) detectable bands were observed in 8 PCa samples, 1 cell line (LNCaP) and 1 benign sample (1024_C).

Supplemental Figure 2. FISH SLC45A3 b/a assay.

To assess for rearrangement of SLC45A3, we employed a break-apart (b/a) FISH assay as previously described(25). The centromeric and telomeric probes for SLC45A3 were

RP11-249H15 and RP11-131E5, respectively. Correct chromosomal probe localization was confirmed on normal lymphocyte metaphase preparations. For each sample a minimum of 100 nuclei were analyzed.

Sequence Information for the different SLC45A3-ELK4 mRNA variants (GeneBank

accession numbers are pending).

Variant 1: SLC45A3 (exon 1) -ELK4 (exon 2)

AACCTGGAGATTTAAAAGCCGCCGGCTGGCGCGCGTGGGGGGCAAGGAAGGGGGGGCGGAACCAGCCTGCACGCGCT GGCTCCGGGTGACAGCCGCGCGCCTCGGCCAGCTCATTGCTATGGACAGTGCTATCACCCTGTGGCAGTTCCTTCTTCA GCTCCTGCAGAAGCCTCAGAACAAGCACATGATCTGTTGGACCTCTAATGATGGGCAGTTTAAGCTTTTGCAGGCAGAA GAGGTGGCTCGTCTCTGGGGGATTCGCAAGAACAAGCCTAACATGAATTATGACAAACTCAGCCGAGCCCTCAGATAC TATTATGTAAAG

Variant 2: SLC45A3 (exon 1)-SLC45A3 (beginning of exon 2)-ELK4 (exon 2)

AACCTGGAGATTTAAAAGCCGCCGGCTGGCGCGCGTGGGGGGCAAGGAAGGGGGGGCGGAACCAGCCTGCACGCGCT GGCTCCGGGTGACAGCCGCGCGCCTCGGCCAGGATCTGAGTGATGAGACGTGTCCCCACTGAGGTGCCCCACAGCAGC AGGTGTTGAGCATGGGCTGAGAAGCTGGACCGGCACCAAAGGGCTGGCAGAAATGGGCGCCTGGCTGATTCCTAGGCA GTTGGCGGCAGCAAGGAGGAGAGGCCGCAGCTTCTGGAGCAGAGCCGAGACGAAGCAGTTCTGGAGTGCCTGAACGG CCCCCTGAGCCCTACCCGCCTGGCCCACTATGGTCCAGAGGCTGTGGGTGAGCCGCCTGCTGCGGCACCGGAAAGCCC AGCTCTTGCTGGTCAACCTGCTAACCTTTGGCCTGGAGGTGTGTTTGGCCGCAGGCATCACCTATGTGCCGCCTCTGCTG CTGGAAGTGGGGGTAGAGGAGAAGTTCATGACCATGGTGCTGGCTCATTGCTATGGACAGTGCTATCACCCTGTGGCA GTTCCTTCTTCAGCTCCTGCAGAAGCCTCAGAACAAGCACATGATCTGTTGGACCTCTAATGATGGGCA

Variant 3: SLC45A3 (exon 1)-SLC45A3 (beginning of exon 2)-SLC45A3 (end of exon 2)- ELK4 (exon 2)

AACCTGGAGATTTAAAAGCCGCCGGCTGGCGCGCGTGGGGGGCAAGGAAGGGGGGGCGGAACCAGCCTGCACGCGCT GGCTCCGGGTGACAGCCGCGCGCCTCGGCCAGGATCTGAGTGATGAGACGTGTCCCCACTGAGGTGCCCCACAGCAGC TCTTGCTGGTCAACCTGCTAACCTTTGGCCTGGAGGTGTGTTTGGCCGCAGGCATCACCTATGTGCCGCCTCTGCTGCTG GAAGTGGGGGTAGAGGAGAAGTTCATGACCATGGTGCTGGCTCATTGCTATGGACAGTGCTATCACCCTGTGGCAGTTC CTTCTTCAGCTCCTGCAGAAGCCTCAGAACAAGCACATGATCTGTTGGACCTCTAATGATGGGCA

Variant 4: SLC45A3 (exon 1)-SLC45A3 (beginning of exon 2)-SLC45A3 (end of exon 4)- intergenic sequence between SLC45A3 and ELK4-ELK4 (exon 2)

AACCTGGAGATTTAAAAGCCGCCGGCTGGCGCGCGTGGGGGGCAAGGAAGGGGGGGCGGAACCAGCCTGCACGCGCT GGCTCCGGGTGACAGCCGCGCGCCTCGGCCAGGATCTGAGTGATGAGACGTGTCCCCACTGAGGTGCCCCTACACACT GGCCTCCCTCTACCACCGGGAGAAGCAGTGGAGGACTTTTGACCCGTCTCCTCACCTTCTGATACACACCAACCAACCAGTCAAC CAGCCATTGCTGTTTACTGGATACCTGCTCATTGCTATGGACAGTGCTATCACCCTGTGGCAGTTCCTTCTTCAGCTCCTGCA GAAGCCTCAGAACAAGCACATGATCTGTTGGACCTCTAATGATGGGCA

Variant 5: SLC45A3 (end of exon 3)-SLC45A3 (exon 4)-intergenic sequence between SLC45A3 and ELK4-ELK4 (exon 2) from 5’ RACE.

TGGGCCCCACCGAGCCAGCAGAAGGGCTGTCGGCCCCCTCCTTGTCGCCCCACTGCTGTCCATGCCGGGCCCGCTTGGC TTTCCGGAACCTGGGCGCCCTGCTTCCCCGGCTGCACCAGCTGTGCTGCCGCATGCCCCGCACCCTGCGCCGGCTCTTC GTGGCTGAGCTGTGCAGCTGGATGGCACTCATGACCTTCACGCTGTTTTACACGGATTTCGTGGGCGAGGGGCTGTACC AGGGCGTGCCCAGAGCTGAGCCGGGCACCGAGGCCCGGAGACACTATGATGAAGGCGTTCGGATGGGCAGCCTGGGG CTGTTCCTGCAGTGCGCCATCTCCCTGGTCTTCTCTCTGGTCATGGACCGGCTGGTGCAGCGATTCGGCACTCGAGCAGT CTATTTGGCCAGTGTGGCAGCTTTCCCTGTGGCTGCCGGTGCCACATGCCTGTCCCACAGTGTGGCCGTGGTGACAGCTT CAGCCGCCCTCACCGGGTTCACCTTCTCAGCCCTGCAGATCCTGCCCTACACACTGGCCTCCCTCTACCACCGGGAGAA GCAGTGGAGGACTTTTGACCCGTCTCCTCACCTTCTGATACACACCAACCAACCAGTCAACCAGCCATTGCTGTTTACT GGATACCTGCTCATTGCTATGGACAGTGCTATCACCCTGTGGCAGTTCCTTCTTCAGCTCCTGCAGAAGCCTCAGAACA AGCACATGATCTGTTGGACCTCTAATGATGGGCAGTTTAAGCTTTTGCAGGCAGAAGAGGTGG

Primer Information for the quantitative PCR assay for chr1q32.1

Amplicon Amplicon Tm # Location Length Primers Primer (5'-3) Value GC % 1 chr1:203872537 234bp Forward GTCCACGACTTCCAGCATTT 60.1 50.0 203872770 Reverse TCAAACTCCACCCTTTCCAG 60.1 50.0

5 chr1:203876382 236bp Forward CAACAAGACATTTTCAGTTAAGGGT 59.9 36.0 203876617 Reverse GGCAAAACAAACAGGTATGCTATAA 60.6 36.0

6 chr1:203876970 237bp Forward ACAGCTTTCCTTGCTCTCCA 60.1 50.0 203877206 Reverse TGGCATCTGAAGAGGTTGAA 59.4 45.0

8 chr1:203878442 217bp Forward ATTCCATCCTCAGCTAACAGGTAA 60.4 41.7 203878658 Reverse CAAGGTGACAGTGTTTTGATGG 60.4 45.5

9 chr1:203879147 193bp Forward CATACCCTTAGAGGTAGGTAACAGC 58.8 48.0 203879339 Reverse AAGATGTGAATGGCAGTGGA 59.1 45.0

10 chr1:203880053 210bp Forward CACACTGAAACAAAAGCCACA 59.8 42.9 203880262 Reverse CTTTTGGGCAAGTGGACAAC 60.5 50.0

11 chr1:203881426 226bp Forward GCCAGATAACCCAGGCTGTA 60.1 55.0 203881651 Reverse GCCTTCATGCATTAGCCATT 60.1 45.0

12 chr1:203882157 239bp Forward GTGCTGTTAGAAATAACTTTCCTGG 59.6 40.0 203882395 Reverse GAGTTCTCAGTTTTCCCTGTGG 60.2 50.0

13 chr1:203883436 206bp Forward TCCACACTCTTCACCCATCA 60.1 50.0 203883641 Reverse CCTGTATGCTGAGCCTCATG 59.4 55.0

14 chr1:203884232 211bp Forward TATTGGGTGCCAGAAAGTCC 59.9 50.0 203884442 Reverse CTCCCTGCAGAGCCAGTTAC 59.2 55.0

17 chr1:203891322 235bp Forward CCAACATGGGCAACATCTCT 60.9 50.0 203891556 Reverse TGGGTTCAGGTGATGTCAGA 60.1 50.0

18 chr1:203892750 223bp Forward CAAGCCCTTGCACAGGTTAT 60.1 50.0 203892972 Reverse CATGGGAATAGGGAATGCAC 60.2 50.0

19 chr1:203893840 216bp Forward AAACCGCACTTTGTGCTTCT 59.9 45.0 203894055 Reverse CTTCAGGTCTCAACGGCTTC 60.0 55.0 (EXON#4 of SLC45A3)

Reference chr1:155205397 204bp Forward TCTCTGCTCCCTCACTCTCAA 60.3 52.4 155205600 Reverse TGTGCCTCTTCCATCGTTCT 60.8 50.0 ARHGEF Introgenic