title: Testis specific Y-like 5: gene expression, methylation and implications for drug sensitivity in prostate carcinoma.
abstract: TSPYL5, a putative tumor suppressor gene, belongs to the nucleosome assembly protein family. The chromosomal location of the TSPYL5 gene is 8Q22.1, and its exact role in prostate cancer etiology remains unclear. Further TSPYL5 gene and protein expression in prostate carcinoma cells and diseased tissues including its susceptibility for epigenetic silencing is unknown. Also, not known is the variation in TSPYL5 protein expression with regards to progression of prostatic carcinoma and its possible role in drug sensitivity.
  
  
  
  TSPYL5, DNMT-1 and DNMT-B gene expression in DU145, LNCaP and RWPE-1 cells and prostate tumor tissues was analyzed by qRT-PCR and RT-PCR. Demethylation experiments were done by treating DU145 and LNCaP cells with 5-aza-2'-deoxycytidine in vitro. Methylation analysis of TSPYL5 gene was performed by methylation specific PCR and pyrosequencing. TSPYL5 protein expression in benign and diseased prostate tumor tissues was performed by immunohistochemistry and in the cells by Western blotting.
  
  
  
  TSPYL5 was differentially expressed in non-tumorigenic prostate epithelial cells (RWPE-1), androgen independent (DU145), dependent (LNCaP) prostate carcinoma cells and tissues. Methylation-specific PCR and pyrosequencing analysis identified an inverse relationship between DNA methylation and expression leading to the silencing of TSPYL5 gene. Treatment of prostate carcinoma cells in which TSPYL5 was absent or low (DU145 and LNCaP) with the demethylating agent 5-aza-2'-deoxycytidine upregulated its expression in these cells. Immunohistochemical studies clearly identified TSPYL5 protein in benign tissue and in tumors with Gleason score (GS) of 6 and 7. TSPYL5 protein levels were very low in tumors of GS ≥ 8. TSPYL5 overexpression in LNCaP cells increased the cell sensitivity to chemotherapy drugs such as docetaxel and paclitaxel, as measured by the cellular viability. Furthermore, the cells also exhibited reduced CDKN1A expression with only marginal reduction in pAKT.
  
  
  
  Decrease in TSPYL5 protein in advanced tumors might possibly function as an indicator of prostate tumor progression. Its absence due to methylation-induced silencing can lead to reduced drug sensitivity in prostate carcinoma.
authors.affiliation: Comparative Oncology Radiobiology and Epigenetics Laboratory, College of Veterinary Medicine and Surgery, University of Missouri, 1600 E Rollins, W-143 Veterinary Medicine Building, Columbia, MO, 65211, USA. kumars@missouri.edu.
authors.forename: Senthil R
authors.initials: SR
authors.lastname: Kumar
authors.affiliation: Comparative Oncology Radiobiology and Epigenetics Laboratory, College of Veterinary Medicine and Surgery, University of Missouri, 1600 E Rollins, W-143 Veterinary Medicine Building, Columbia, MO, 65211, USA.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Bryan
authors.affiliation: Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
authors.forename: Magda
authors.initials: M
authors.lastname: Esebua
authors.affiliation: Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, 65211, USA.
authors.forename: James
authors.initials: J
authors.lastname: Amos-Landgraf
authors.affiliation: Comparative Oncology Radiobiology and Epigenetics Laboratory, College of Veterinary Medicine and Surgery, University of Missouri, 1600 E Rollins, W-143 Veterinary Medicine Building, Columbia, MO, 65211, USA.
authors.forename: Tanner J
authors.initials: TJ
authors.lastname: May
mesh_terms: D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology / Q000627:therapeutic use; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D000076123:DNA (Cytosine-5-)-Methyltransferase 1 / Q000235:genetics; D019175:DNA Methylation; D000077209:Decitabine; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction
chemical_list: D000964:Antimetabolites, Antineoplastic; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D009687:Nuclear Proteins; C527859:TSPYL5 protein, human; D000077209:Decitabine; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; C000619380:DNMT1 protein, human; D001374:Azacitidine
keywords: Drug sensitivity; Methylation; Prostate carcinoma; Putative tumor suppressor gene