title: ERG oncoprotein expression in prostate carcinoma patients of different ethnicities.
abstract: Overexpression of the erythroblast transformation-specific-related gene (ERG) oncoprotein due to transmembrane protease, serine 2 (TMPRSS2)-ERGfusion, the most prevalent genomic alteration in prostate cancer (CaP), is more frequently observed among Caucasian patients compared to patients of African or Asian descent. To the best of our knowledge, this is the first study to investigate the prevalence ofERGalterations in a multiethnic cohort of CaP patients. A total of 191 formalin-fixed paraffin-embedded sections of transrectal ultrasound-guided prostate biopsy specimens, collected from 120 patients treated at the Sime Darby Medical Centre, Subang Jaya, Malaysia, were analyzed for ERG protein expression by immunohistochemistry using the anti-ERG monoclonal antibody 9FY as a surrogate for the detection ofERGfusion events. The overall frequency of ERG protein expression in the population evaluated in this study was 39.2%. Although seemingly similar to rates reported in other Asian communities, the expression of ERG was distinct amongst different ethnic groups (P=0.004). Malaysian Indian (MI) patients exhibited exceedingly high expression of ERG in their tumors, almost doubling that of Malaysian Chinese (MC) patients, whereas ERG expression was very low amongst Malay patients (12.5%). When collectively analyzing data, we observed a significant correlation between younger patients and higher ERG expression (P=0.04). The prevalence of ERG expression was significantly different amongst CaP patients of different ethnicities. The higher number of ERG-expressing tumors among MI patients suggested that theTMPRSS2-ERGfusion may be particularly important in the pathogenesis of CaP amongst this group of patients. Furthermore, the more frequent expression of ERG among the younger patients analyzed suggested an involvement of ERG in the early onset of CaP. The results of this study underline the value of using ERG status to better understand the differences in the etiology of CaP initiation and progression between ethnic groups.
authors.affiliation: Oral Cancer Research Team, Cancer Research Initiatives Foundation (CARIF), 2nd Floor Outpatient Centre, Sime Darby Medical Centre, Subang Jaya, Selangor 47500, Malaysia.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Kelly
authors.affiliation: Oral Cancer Research Team, Cancer Research Initiatives Foundation (CARIF), 2nd Floor Outpatient Centre, Sime Darby Medical Centre, Subang Jaya, Selangor 47500, Malaysia.
authors.forename: Yink Heay
authors.initials: YH
authors.lastname: Kong
authors.affiliation: Department of Surgery, Center for Prostate Disease Research, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
authors.forename: Albert
authors.initials: A
authors.lastname: Dobi
authors.affiliation: Department of Surgery, Center for Prostate Disease Research, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
authors.forename: Shiv
authors.initials: S
authors.lastname: Srivastava
authors.affiliation: Joint Pathology Center, Silver Spring, MD 20910, USA.
authors.forename: Isabell A
authors.initials: IA
authors.lastname: Sesterhenn
authors.affiliation: Sime Darby Medical Centre, Subang Jaya, Selangor 47500.
authors.forename: Rajadurai
authors.initials: R
authors.lastname: Pathmanathan
authors.affiliation: Sime Darby Medical Centre, Subang Jaya, Selangor 47500 ; Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
authors.forename: Hui Meng
authors.initials: HM
authors.lastname: Tan
authors.affiliation: Department of Surgery, Center for Prostate Disease Research, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
authors.forename: Shyh-Han
authors.initials: SH
authors.lastname: Tan
authors.affiliation: Oral Cancer Research Team, Cancer Research Initiatives Foundation (CARIF), 2nd Floor Outpatient Centre, Sime Darby Medical Centre, Subang Jaya, Selangor 47500, Malaysia.
authors.forename: Sok Ching
authors.initials: SC
authors.lastname: Cheong
keywords: Malaysia; prostate cancer; serine 2-erythroblast transformation-specific-related gene fusion; transmembrane protease