| Abstract: |
DNA copy number analysis was performed, using single-nucleotide polymorphism mapping arrays, to fine map genomic imbalances in human malignant mesothelioma (MM) cell lines derived from primary tumors. Chromosomal losses accounted for the majority of genomic imbalances. All 22 cell lines examined showed homozygous deletions of 9p21.3, centering at the CDKN2A/ARF and CDKN2B loci. Other commonly underrepresented segments included 1p36, 1p22, 3p21-22, 4q13, 4q34, 11q23, 13q12-13, 14q32, 15q15, 18q12, and 22q12, each observed in 55-90% of cell lines. Focal deletions of 11q23 encompassed the transcriptional repressor gene promyelocytic leukemia zinc finger (PLZF), which was validated by analysis of genomic DNA using real-time polymerase chain reaction (PCR). Semi-quantitative RT-PCR and immunoblot analysis revealed that PLZF is greatly downregulated in MM cell lines compared with non-malignant mesothelial cells. Ectopic expression of PLZF in PLZF-deficient MM cells resulted in decreased cell viability, reduced colony formation, as well as increased apoptosis, the latter based on results of various cell death assays and the observation of increased cleavage of caspase 3, PARP, and Mcl-1. These data indicate that deletions of PLZF are a common occurrence in MM and that downregulation of PLZF may contribute to MM pathogenesis by promoting cell survival. © 2010 Macmillan Publishers Limited All rights reserved. |
| Keywords: |
controlled study; unclassified drug; human cell; gene deletion; protein function; cell death; cell viability; cell survival; cell cycle; apoptosis; down-regulation; chromosome 9p; gene locus; chromosomes, human, pair 9; transcription factor; caspase 3; cancer cell culture; tumor cells, cultured; carcinogenesis; gene expression regulation; blotting, western; gene expression regulation, neoplastic; reverse transcriptase polymerase chain reaction; protein mcl 1; kruppel-like transcription factors; malignant mesothelioma; mesothelioma; genomics; down regulation; cyclin-dependent kinase inhibitor p16; tumor suppressor protein p14arf; gene dosage; chromosome deletion; zinc finger protein; chromosome loss; nicotinamide adenine dinucleotide adenosine diphosphate ribosyltransferase; proto-oncogene proteins c-bcl-2; chromosome 3p; chromosome 11q; chromosome 4q; chromosome 14q; chromosome 1p; tumor suppressors; chromosome 15q; chromosome 22q; poly(adp-ribose) polymerases; genomic imbalances; plzf; promyelocytic leukemia zinc finger protein; arf gene; cdkn 2a gene; cdkn 2b gene; chromosome 13q; chromosome 18q; colony formation; plzf gene; repressor gene; cyclin-dependent kinase inhibitor p15
|
