論文 - 詳細
| RRC ID | 65137 |
|---|---|
| 著者 | Trisdale SK, Schwab NM, Hou X, Davis JS, Townson DH. |
| タイトル | Molecular manipulation of keratin 8/18 intermediate filaments: modulators of FAS-mediated death signaling in human ovarian granulosa tumor cells. |
| ジャーナル | J Ovarian Res |
| Abstract |
BACKGROUND:Granulosa cell tumors (GCT) are a rare ovarian neoplasm but prognosis is poor following recurrence. Keratin intermediate filaments expressed in these tumors are a diagnostic marker, yet paradoxically, may also constitute a target for therapeutic intervention. In the current study, we evaluated keratin 8/18 (K8/18) filament expression as a mechanism of resistance to apoptosis in GCT, specifically focusing on regulation of the cell surface death receptor, Fas (FAS). METHODS:The GCT cell line, KGN, was transiently transfected with siRNA to KRT8 and KRT18 to reduce K8/18 filament expression. Expression of K8/18, FAS, and apoptotic proteins (PARP, cleaved PARP) were evaluated by fluorescence microscopy, flow cytometric analysis, and immunoblotting, respectively. The incidence of FAS-mediated apoptosis in KGN cells was measured by caspase 3/7 activity. All experiments were performed independently three to six times, using a fresh aliquot of KGN cells for each experiment. Quantitative data were analyzed by one- or two-way analysis of variance (ANOVA), followed by a Tukey's post-test for multiple comparisons; differences among means were considered statistically significant at P < 0.05. RESULTS:Control cultures of KGN cells exhibited abundant K8/18 filament expression (~90 % of cells), and minimal expression of FAS (<25 % of cells). These cells were resistant to FAS-activating antibody (FasAb)-induced apoptosis, as determined by detection of cleaved PARP and measurement of caspase 3/7 activity. Conversely, siRNA-mediated knock-down of K8/18 filament expression enhanced FAS expression (> 70 % of cells) and facilitated FasAb-induced apoptosis, evident by increased caspase 3/7 activity (P < 0.05). Additional experiments revealed that inhibition of protein synthesis, but not MEK1/2 or PI3K signaling, also prompted FasAb-induced apoptosis. CONCLUSIONS:The results demonstrated that K8/18 filaments provide resistance to apoptosis in GCT by impairing FAS expression. The abundance of keratin filaments in these cells and their role in apoptotic resistance provides a greater mechanistic understanding of ovarian tumorgenicity, specifically GCT, as well as a clinically-relevant target for potential therapeutic intervention. |
| 巻・号 | 9 |
| ページ | 8 |
| 公開日 | 2016-2-24 |
| DOI | 10.1186/s13048-016-0217-z |
| PII | 10.1186/s13048-016-0217-z |
| PMID | 26911253 |
| PMC | PMC4765146 |
| MeSH | Apoptosis Cell Line, Tumor Female Gene Expression Gene Expression Regulation, Neoplastic Gene Knockdown Techniques Granulosa Cell Tumor / genetics Granulosa Cell Tumor / metabolism* Granulosa Cell Tumor / pathology Humans Keratin-18 / genetics Keratin-18 / metabolism* Keratin-8 / genetics Keratin-8 / metabolism* Ovarian Neoplasms / genetics Ovarian Neoplasms / metabolism* Ovarian Neoplasms / pathology Signal Transduction fas Receptor / antagonists & inhibitors fas Receptor / physiology* |
| IF | 2.469 |
| リソース情報 | |
| ヒト・動物細胞 | KGN(RCB1154) |