Distinct classes of chromosomal rearrangements create oncogenic ETS gene fusions in prostate cancer.
Recently, we identified recurrent gene fusions involving the 5' untranslated region of the androgen-regulated gene TMPRSS2 and the ETS (E26 transformation-specific) family genes ERG, ETV1 or ETV4 in most prostate cancers. Whereas TMPRSS2-ERG fusions are predominant, fewer TMPRSS2-ETV1 cases have been identified than expected on the basis of the frequency of high (outlier) expression of ETV1 (refs 3-13). Here we explore the mechanism of ETV1 outlier expression in human prostate tumours and prostate cancer cell lines. We identified previously unknown 5' fusion partners in prostate tumours with ETV1 outlier expression, including untranslated regions from a prostate-specific androgen-induced gene (SLC45A3) and an endogenous retroviral element (HERV-K_22q11.23), a prostate-specific androgen-repressed gene (C15orf21), and a strongly expressed housekeeping gene (HNRPA2B1). To study aberrant activation of ETV1, we identified two prostate cancer cell lines, LNCaP and MDA-PCa 2B, that had ETV1 outlier expression. Through distinct mechanisms, the entire ETV1 locus (7p21) is rearranged to a 1.5-megabase prostate-specific region at 14q13.3-14q21.1 in both LNCaP cells (cryptic insertion) and MDA-PCa 2B cells (balanced translocation). Because the common factor of these rearrangements is aberrant ETV1 overexpression, we recapitulated this event in vitro and in vivo, demonstrating that ETV1 overexpression in benign prostate cells and in the mouse prostate confers neoplastic phenotypes. Identification of distinct classes of ETS gene rearrangements demonstrates that dormant oncogenes can be activated in prostate cancer by juxtaposition to tissue-specific or ubiquitously active genomic loci. Subversion of active genomic regulatory elements may serve as a more generalized mechanism for carcinoma development. Furthermore, the identification of androgen-repressed and insensitive 5' fusion partners may have implications for the anti-androgen treatment of advanced prostate cancer.
Michigan Center for Translational Pathology, Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
Scott A
SA
Tomlins
Bharathi
B
Laxman
Saravana M
SM
Dhanasekaran
Beth E
BE
Helgeson
Xuhong
X
Cao
David S
DS
Morris
Anjana
A
Menon
Xiaojun
X
Jing
Qi
Q
Cao
Bo
B
Han
Jindan
J
Yu
Lei
L
Wang
James E
JE
Montie
Mark A
MA
Rubin
Kenneth J
KJ
Pienta
Diane
D
Roulston
Rajal B
RB
Shah
Sooryanarayana
S
Varambally
Rohit
R
Mehra
Arul M
AM
Chinnaiyan
D000818:Animals; D045744:Cell Line, Tumor; D002869:Chromosome Aberrations; D004268:DNA-Binding Proteins / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D009857:Oncogenes / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; C095239:ETV1 protein, human; D015514:Oncogene Proteins, Fusion; D050784:Proto-Oncogene Protein c-ets-1; D014157:Transcription Factors