Cancer Genetics and Signaling Program, Fox Chase Cancer Center, Philadelphia, PA 19111-2497, USA.
Oncogene. 2010 Mar 18;29(11):1633-40. doi: 10.1038/onc.2009.455. Epub 2009 Dec 14.
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.
采用单核苷酸多态性图谱分析，对源自原发性肿瘤的人类恶性间皮瘤（MM）细胞系的基因组失衡进行精细作图。染色体缺失占基因组失衡的大多数。所有 22 个检测的细胞系均显示 9p21.3 的纯合性缺失，定位于 CDKN2A/ARF 和 CDKN2B 基因座。其他常见的代表性缺失区域包括 1p36、1p22、3p21-22、4q13、4q34、11q23、13q12-13、14q32、15q15、18q12 和 22q12，每个区域在 55%-90%的细胞系中均有观察到。11q23 的局灶性缺失包括转录抑制因子基因早幼粒细胞白血病锌指（PLZF），通过使用实时聚合酶链反应（PCR）对基因组 DNA 进行分析验证了这一点。半定量 RT-PCR 和免疫印迹分析显示，PLZF 在 MM 细胞系中的表达水平明显低于非恶性间皮细胞。在 PLZF 缺陷的 MM 细胞中异位表达 PLZF 导致细胞活力降低、集落形成减少以及凋亡增加，后者基于各种细胞死亡测定的结果以及观察到 caspase 3、PARP 和 Mcl-1 的切割增加。这些数据表明 PLZF 的缺失在 MM 中很常见，PLZF 的下调可能通过促进细胞存活而促进 MM 的发病机制。
