The transcription factor ZNF217 is often amplified in ovarian cancer, but its role in neoplastic progression is unknown. We introduced ZNF217-HA by adenoviral and retroviral infection into normal human ovarian surface epithelial cells (OSE), i.e., the source of ovarian cancer, and into SV40 Tag/tag expressing, p53/ pRB-deficient OSE with extended but finite life spans (IOSE). In OSE, ZNF217-HA reduced cell-substratum adhesion and accelerated loss of senescent cells, but caused no obvious proneoplastic changes. In contrast, ZNF217-HA transduction into IOSE yielded two permanent lines, I-80RZ and I-144RZ, which exhibited telomerase activity, stable telomere lengths, anchorage independence and reduced serum dependence, but were not tumorigenic in SCID mice. This immortalization required short-term EGF treatment near the time of crisis. The permanent lines were EGF-independent, but ZNF217-dependent since siRNA to ZNF217 inhibited anchorage independence and arrested growth. Array CGH revealed genomic changes resembling those of ovarian carcinomas, such as amplicons at 3q and 20q, and deletions at 4q and 18, associated with underexpressed annexin A10, N-cadherin, desmocollin 3 and PAI-2, which have been reported as tumor suppressors. The lines overexpressed EEF1A2, SMARA3 and STAT1 and underexpressed other oncogenes, tumor suppressors and extracellular matrix/adhesion genes. The results implicate ZNF217 as an ovarian oncogene, which is detrimental to senescing normal OSE cells but contributes to neoplastic progression in OSE with inactivated p53/RB. The resemblance of the genomic changes in the ZNF217-overexpressing lines to ovarian carcinomas provides a unique model to investigate interrelationships between these changes and ovarian neoplastic phenotypes. ' 2007 Wiley-Liss, Inc.Key words: ZNF217; oncogene; ovarian cancer; immortalization The candidate oncogene ZNF217, predicted to encode alternatively spliced Krúppel-like transcription factors, was originally identified because of its location in an amplicon on chromosome 20q13.2 in breast cancer cell lines and tumors and by its recurrent expression in other malignancies. 1 ZNF217 is expressed in normal tissues, and is overexpressed in all cell lines and tumors where the gene locus is amplified. 2 Amplification of 20q, which involves a large number of potentially relevant genes, has since been described in many types of human cancers. 3-10 The 20q region, and ZNF217 specifically, is amplified in a high proportion of ovarian carcinomas, and expression levels of ZNF217 correlate with their copy numbers in primary ovarian cancers. 11,12 However, because of the coexistence of other amplified genes in the same region, it has been difficult to define the specific influence of ZNF217 on malignant progression. An increased copy number of ZNF217 is associated with reduced survival of ovarian cancer patients. 13,14 In experimental systems, 20q13 amplification has been associated with genome instability and immortalization in cultured human uroepithelial cells. 15,16 Furthermor...

Caspase-1 plays a key role in the processing of cytokines and in the apoptosis of neurons and macrophages. Whether it also causes apoptosis of cancer cells has been unclear. In this study, we screened an array of apoptosis-related proteins in ovarian carcinoma cell lines and their tissue of origin, ovarian surface epithelium (OSE). Caspase-1A protein was abundant in OSE and in nontumorigenic OSE with extended but limited life spans (immortalized OSE), but was reduced in the cancer lines A2780 and OVCAR10. By Western blot and immunofluorescence, caspase-1A levels were greatly reduced in six of eight ovarian carcinoma lines compared with OSE. By realtime reverse transcription-PCR, steady-state transcripts of the CASP1 gene were proportional to protein levels. Caspase-1A overexpression caused significant apoptosis, but overexpression of a caspase-1A mutant without catalytic activity did not, confirming that the effect was caspase-1A-specific. Immunofluorescence of caspase-1A and terminal nucleotidyl transferase-mediated dUTP-X nick end labeling colocalization clearly established a link between apoptosis and caspase-1A expression. Caspase-9 and caspase-3 were activated in caspase-1A overexpressing A2780 cells, suggesting involvement of an intrinsic apoptotic pathway. Caspase-1A overexpression did not change the apoptotic effect of cisplatin in A2780 and OVCAR10 cells, suggesting that this agent activates a different pathway. Immunohistochemically, caspase-1 was lower in ovarian serous carcinomas than in OSE. Our study indicates, for the first time, that caspase-1A is proapoptotic in ovarian cancer cells, and raises the possibility that its downregulation is one of the mechanisms which increase resistance to apoptosis in cancer cells. (Cancer Res 2005; 65(19): 8591-6)

Modulation of Immune check point regulators, especially the PD-1/PD-L1 axis, plays a critical role in successful management of a small proportion of lung cancer patients, but not so effective in the rest of lung cancer patients. A better understanding of immunotherapy non-responsive or resistant patients therefore warranted for future development of novel therapeutics. The newly identified regulator CMTM6 (CKLF-like MARVEL transmembrane domain containing 6) has been reported to serves as the stabilizer of PD-L1 and enhances the inhibitory effect of PD-L1 on immune system in both cell line and animal models, but its clinical relevance associated with PD-L1 is unknown and the current study is designed to address this question. The study using immunohistochemistry demonstrated that CMTM6 positivity from 15 out of 19 types of cancers with our in-house tissue microarray, and PD-L1 expression is always found only in CMTM6 positive cancers. CMTM6 and PD-L1 expression were analyzed in 81 lung cancer patient sample, and we observed that CMTM6 expression correlated with cancer histotypes and inversely correlated with cancer metastases, but not with patients’ age and gender. No PD-L1 expression was observed in negative CMTM6 samples. Higher expression PD-L1 is also associated with higher CMTM6 expression. In summary, CMTM6 expression is associated with PD-L1 expression, as well as lung cancer histotypes and metastasis. The results thus for the first time confirmed earlier reports on CMTM6/PD-L1 connection, from a clinical aspect of analysis.

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