Research has shown that deletions of PTEN occur at a very high frequency in prostate cancer.1 Other studies have demonstrated an association between decreased PTEN protein expression and a higher Gleason grade and advanced tumor stage.2 In a study by Yoshimoto it was demonstrated that the presence of PTEN genomic losses are frequent at diagnosis and are a significant prognostic marker for the subsequent development of clinically advanced disease.3 The TMPRSS2: ERG fusion gene, is a transcription promoter that contributes to the proliferation and invasive capacity of cancer cells.4 The combination of PTEN loss and ERG overexpression has been associated with aggressive disease.5
1. Interphase FISH analysis of PTEN in histologic sections shows genomic deletions in 68% of primary prostate cancer and 23% of high-grade prostatic intra-epithelial neoplasias. Yoshimoto M, Cutz JC, Nuin PA, Joshua AM, Bayani J, Evans AJ, Zielenska M, Squire JA. Cancer Genet Cytogenet 2006. 169: 128–137.
2. Loss of PTEN expression in paraffin-embedded primary prostate cancer correlates with high Gleason score and advanced stage. McMenamin ME, Soung P, Perera S, Kaplan I, Loda M, Sellers WR. Cancer Res 1999. 59: 4291–4296
3. FISH analysis of 107 prostate cancers shows that PTEN genomic deletion is associated with poor clinical outcome. Yoshimoto M, Cunha IW, Coudry RA, et al. British J of Cancer. 2007;97:678-685.
4. ETS factors reprogram the androgen receptor cistrome and prime prostate tumorigenesis in response to PTEN loss. Yu Chen, Ping Chi, Shira Rockowitz, Phillip J Iaquinta, Tambudzai Shamu. Nature Medicine 19, 1023–1029 (2013).
5. TMPRSS2-ERG and PTEN loss in prostate cancer. Jeremy A Squire. Nature Genetics 41, 509 – 510 (2009)
6. Clinical and Laboratory Standards Institute (CLSI). Protection of Laboratory workers from occupationally Acquired Infections; Approved Guideline-Fourth Edition CLSI document M29-A4 Wayne, PA 2014.