The expression of Apollon gene silenced by RNA interference combined with ligustrazine intervention may increase the sensitivity of leukemia cells to chemotherapeutic agents / 肿瘤

ABSTRACT

Objective: To investigate whether the expression of Apollon (an apoptosis inhibitory gene) silenced by using RNA interference (RNAi) technology in combination with tetramethylpyrazine (TMP) intervention can increase the sensitivity of human myeloid leukemia K562 cells to vincristine (VCR) and daunorubicin (DNR). Methods: Using the best small interference RNA (siRNA) targeting Apollon gene which was screened out in a previous experiment, the eukaryotic expression vector pGPHI-GFP-Neo-Apollon was constructed. Then, the K562 cells were transfected with pGPHI-GFP-Neo-Apollon by LipofectamineTM 2000 and screened out by G418. After Apollon siRNA was transfected stably into K562 cells, the expressions of Apollon mRNA and protein were detected by reverse transcription (RT)-PCR and immunofluorescence, respectively. The sensitivities to chemotherapeutic agents VCR and DNR after RNAi in combination with TMP intervention were detected by MTT method, and apoptosis rate was detected by flow cytometry. Results: pGPHI-GFP-Neo-Apollon vector was constructed successfully and it could express stably in K562 cells, which silenced the expressions of Apollon mRNA and protein effectively. The sensitivity to VCR or DNR increased significantly after RNAi in combination with TMP intervention. The half inhibitory concentration (IC50) values of VCR and DNR were significantly lower than those in the group of TMP intervention alone (P < 0.05). The apoptosis rate of K562 cells after transfection with Apollon siRNA in combination with TMP intervention was significantly increased comparing with that of the untreated control group and TMP intervention alone group (P < 0.05). Conclusion: RNAi targeting Apollon gene in combination with TMP intervention can obviously increase the sensitivity to VCR or DNR in K562 cells and significantly reduce the dosage of chemotherapeutic agents as well as improve apoptosis induced by chemotherapy. These results suggest that Apollon gene silenced by RNAi in combination with TMP intervention may reverse the drug resistance of leukemia cells. Copyright © 2013 by TUMOR.