[Influencing of hep-2 cell function by RNAi silencing E-cadherin expression].

OBJECTIVE: To explore the function of human laryngeal carcinoma Hep-2 cell after down-regulating the expression of E-cadherin gene to provide theoretical rationales for gene therapy of laryngeal cancer. METHODS: According to the GenBank database, 3 pairs of shRNA sequences of E-cadherin gene were designed and synthesized. shRNAs were transfected into the cell line Hep-2 by liposome. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the silencing effect of E-cadherin expression. The changed capacity of cell proliferation were detected in vitro by methyl thiazolyl tetrazolium (MTT) assay in the transfected Hep-2 cells and the cell proliferation rate (survival rate) was calculated. And Transwell was used to detect the migratory capacity of Hep-2 cells after siRNA transfection. RESULTS: The E-cadherin gene expression of RNAi transfected Hep-2 cells significantly decreased in interference group. And the proliferation of interference group became markedly enhanced. In Transwell test, the migrated cell numbers in interference group were significant higher than those in negative control group (262 ± 15, 288 ± 12, 292 ± 6 vs 74 ± 8, all P < 0.01). CONCLUSIONS: RNA interference silencing of E-cadherin gene expression can significantly enhance the proliferation and migratory capacity of Hep-2 cells. And E-cadherin may be considered as one of gene therapy targets for laryngeal cancer.

Progesterone production requires activation of caspase-3 in preovulatory granulosa cells in a serum starvation model.

Granulosa cells proliferate, differentiate, and undergo apoptosis throughout follicular development. Previous studies have demonstrated that stimulation of progesterone production is accompanied by caspase-3 activation. Moreover, we previously reported that arsenic enhanced caspase-3 activity coupled with progesterone production. Inhibition of caspase-3 activity can significantly inhibit progesterone production induced by arsenic or follicle-stimulating hormone (FSH). Here, we report that serum starvation induces caspase-3 activation coupled with augmentation of progesterone production. Serum starvation also increased the levels of cytochrome P450 cholesterol side chain cleavage enzyme (P450scc) and steroidogenic acute regulatory (StAR) protein, both of which may contribute to progesterone synthesis in preovulatory granulosa cells. Inhibition of caspase-3 activity resulted in a decrease in progesterone production. Deactivation of caspase-3 activity by caspase-3 specific inhibitor also resulted in decreases in P450scc and StAR expression, which may partly contribute to the observed decrease in progesterone production. Our study demonstrates for the first time that progesterone production in preovulatory granulosa cells is required for caspase-3 activation in a serum starvation model. Inhibition of caspase-3 activity can result in decreased expression of the steroidogenic proteins P450scc and StAR. Our work provides further details on the relationship between caspase-3 activation and steroidogenesis and indicates that caspase-3 plays a critical role in progesterone production by granulosa cells.