Title

TMPRSS2-ERG tmprss2-Erg Gene Fusion Is Rare Compared to PTEN Deletions in Stage T1a Prostate Cancer

Document Type

Article

Publication Date

3-1-2017

Publication Title

Molecular carcinogenesis

Abstract

T1a prostate cancers (cancer found incidentally in transurethral resection, <5% of the tissue) are indolent tumors of the transition zone. The overexpression of ERG and the inactivation of PTEN have been shown to be important drivers of carcinogenesis in large series of prostate cancer, but the genetics of transition zone tumors have not been well characterized. We evaluated the status of ERG and PTEN in formalin‐fixed paraffin‐embedded tissue using immunohistochemical and FISH analysis in 54 T1a transition zone tumors. The protein expression of ERG was determined using a rabbit monoclonal antibody and nuclear staining was scored as positive or negative. The genomic status of ERG was determined using three colored FISH using an ERG‐TMPRSS2 tri‐color probe set. The protein expression of PTEN was determined using a rabbit monoclonal antibody and cytoplasmic, and nuclear staining was scored as positive or negative. The genomic status of PTEN was determined using dual color FISH with a PTEN probe and a CEP10 probe. We found ERG rearrangement in 2 of 54 tumors (4%), one with protein overexpression by immunohistochemistry. PTEN inactivation was seen in 13 of 54 tumors (24%). Nine of the 13 PTEN alleles were inactivated by hemizygous deletion. No homozygous PTEN deletion was observed. PTEN deletion and ERG rearrangement were mutually exclusive. ERG rearrangement was rare compared to peripheral zone tumors and to PTEN inactivation in T1a transition zone tumors.

Medical Subject Headings

Aged; Aged, 80 and over; Gene Deletion; Gene Expression Regulation, Neoplastic; Humans; In Situ Hybridization, Fluorescence; Male; Middle Aged; Neoplasm Staging; Oncogene Proteins, Fusion; PTEN Phosphohydrolase; Prostatic Neoplasms

PubMed ID

27500376

Volume

56

Issue

3

First Page

814

Last Page

820

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