Role of Cdc 42 gene in the suppression of filopodia formation induced by non-steroidal anti-inflammatory drugs in breast cancer cells / 肿瘤

ABSTRACT

Objective: To investigate the effect of cell division cycle 42 (Cdc 42) gene on the formation of filopodia suppressed by non-steroidal anti-inflammatory drugs (NSAIDs), and to explore the probable signal transduction pathway involving Cdc 42 in the inhibition effects on migration and invasion abilities of breast cancer cells induced by NSAIDs. Methods: MCF-7 cells were divided into four groups blank control group, NS-398 (100 μmol/L)-treated group, cyclooxygenase-2 (Cox-2) small interfering RNA (siRNA)-transfected group and the negative siRNA-transfected group. The expressions of Cox-2 and Cdc42 mRNAs were detected by real-time fluorogentic quantitative PCR(RFQ-PCR), and the expressions of Cox-2 and Cdc42 proteins were measured by Western blotting. Actin-tracker Green fluorescent probe was used to examined the morphology of filopodias in MCF-7 cells. The invasion ability of MCF-7 cells was detected by using the Martrigel-coated Transwell. Results: The filopodias in MCF-7 cells disappeared in the NS-398-treated group, and the invasion ability of MCF-7 cells was also significantly decreased in this group compared with that in the blank control group (P0.05), and the difference was also not seen in the expression of Cdc42 mRNA or protein between these two groups (P>0.05). The active-Cdc42 level was significantly decreased in the NS-398-treated group compared with that in the blank control group (P<0.05). The filopodias in the Cox-2 siRNA-transfected group disappeared, and the invasion ability of MCF-7 cells transfected with Cox-2 siRNA was significantly decreased compared with that in the negative siRNA-transfected group (P<0.05). The active-Cdc42 level was also significantly decreased in MCF-7 cells transfected with Cox-2 siRNA compared with those transfected with negative siRNA (P<0.05). Conclusion: NSAIDs can suppress the invasion ability of breast cancer cells. This effect may be achieved by inhibiting the activity of Cox-2, decreasing the expression level of active-Cdc42, and suppressing the formation of filopodias.