am-356 and Endometrial-Neoplasms

The TWIK-related acid sensitive K(+) channel-3 (TASK-3) is an oncogenic potassium channel. We investigated the expression of TASK-3 in human ovaries, examined its prognostic significance, and determined effects of TASK-3 blockers on cell proliferation and apoptosis.. Immunofluorescence and western blotting were used to investigate TASK-3 expression in two ovarian cancer cell lines, normal ovarian surface epithelium and cancer. Immunohistochemistry quantified expression in an ovarian cancer tissue microarray. The effect of TASK-3 blocking agents on cell proliferation was investigated with the CellTiter 96® Aqueous Non-Radioactive Cell Proliferation assay and on apoptosis with flow cytometry.. TASK-3 expression was confirmed by immunofluorescence in the SKOV-3 and OVCAR-3 cell lines, normal ovaries (n=4) and ovarian tumours (n=4) and by western blotting in normal ovaries (n=6) and ovarian tumours (n=22). Immunohistochemistry demonstrated immunostaining in 99% of tumours (n=230). Increased immunostaining conferred a survival advantage (p=0.002; median survival of >24 months). TASK-3 blockers caused a significant reduction in cell proliferation and an increase in apoptosis in the SKOV-3 and OVCAR-3 cell lines.. TASK-3 is expressed in epithelial ovarian cancer, conferring a significant survival advantage on patients with increased expression. TASK-3-modulating agents have a significant effect on cell proliferation and apoptosis. Based on these results, we propose that TASK-3 could prove to be both a novel tumour marker and a new therapeutic target in ovarian cancer, but further investigation is required.

Topics: Adenocarcinoma, Clear Cell; Adenocarcinoma, Mucinous; Adult; Aged; Apoptosis; Arachidonic Acids; Blotting, Western; Cell Proliferation; Cystadenocarcinoma, Serous; Endometrial Neoplasms; Female; Flow Cytometry; Fluorescent Antibody Technique; Humans; Immunoenzyme Techniques; Middle Aged; Neoplasm Grading; Neoplasm Staging; Ovarian Neoplasms; Potassium Channels, Tandem Pore Domain; Tissue Array Analysis; Tumor Cells, Cultured; Young Adult

The human endometrial epithelium is pivotal to menstrual cycle progression, implantation and early pregnancy. Endometrial function is directly regulated by local factors that include pH, oxygen tension and ion concentrations to generate an environment conducive to fertilization. A superfamily of potassium channels characterized by two-pore domains (K2P) and encoded by KCNK genes is implicated in the control of the cell resting membrane potential through the generation of leak currents and modulation by various physicochemical stimuli. The aims of the study were to determine the expression and function of K2P channel subtypes in proliferative and secretory phase endometrium obtained from normo-ovulatory women and in an endometrial cancer cell line. Using immunochemical methods, real-time qRT-PCR proliferation assays and electrophysiology. Our results demonstrate mRNA for several K2P channel subtypes in human endometrium with molecular expression of TREK-1 shown to be higher in proliferative than secretory phase endometrium (P < 0.001). The K2P channel blockers methanandamide, lidocaine, zinc and curcumin had antiproliferative effects (P < 0.01) in an endometrial epithelial cancer cell line indicating a role for TASK and TREK-1 channels in proliferation. Tetraethylammonium- and 4-aminopyridine-insensitive outwards currents were inhibited at all voltages by reducing extracellular pH from 7.4 to 6.6. Higher expression of TREK-1 expression in proliferative phase endometrium may, in part, underlie linked to increased cell division. The effects of pH and a lack of effect of non-specific channel blockers of voltage-gated potassium channels imply a role for K2P channels in the regulation of human endometrial function.

Topics: Adult; Arachidonic Acids; Cell Line, Tumor; Cell Proliferation; Curcumin; Endometrial Neoplasms; Endometrium; Epithelial Cells; Female; Gene Expression Regulation; Humans; Hydrogen-Ion Concentration; Lidocaine; Membrane Potentials; Menstrual Cycle; Nerve Tissue Proteins; Ovulation; Potassium Channel Blockers; Potassium Channels, Tandem Pore Domain; Primary Cell Culture; RNA, Messenger