Nestin small interfering RNA (siRNA) reduces cell growth in cultured astrocytoma cells

Nestin is an embryonic intermediate filament that transiently expressed in the neural stem/progenitor cells in the developing central nervous system (CNS). Growing evidence has shown that abundant expression of nestin also occurs in both pathological glial-derived tumor cells and reactive astrocytes in various CNS injuries, implying that nestin may play a crucial role in cell growth or proliferation of astrocyte-derived tumor cells. In the present study, we have investigated the possible role of nestin expression in cell growth or survival of CNS tumor cells by using novel small interfering RNA (siRNA) method in cell culture of rat astrocytoma C6 cell line. The nestin expression and cell growth of the cultured astrocytoma cells were examined after nestin siRNA duplex was delivered by cell transfection for 6 h and cell culture was maintained for 48 h. It revealed an effective suppression influence of nestin siRNA on cell growth of cultured astrocytoma cells in a dose-dependent manner. Quantitative data analysis showed that the doses of nestin siRNA at 30–120 nM significantly decreased both cell numbers and expression levels of nestin mRNA and protein. The nestin siRNA also suppressed expression of cellular glial fibrillary acid protein but showed no obvious influence on expression level of Ki-67 protein (a cell proliferation marker). This study has provided in vitro evidence that nestin siRNA can effectively block nestin expression and reduce cell growth of the cultured C6 astrocytoma cells, strongly suggesting that nestin siRNA-induced suppression of tumor cell growth may provide a potential novel clinical therapy against CNS astroglioma events.