下调βⅢ-tubulin逆转肺腺癌A549/Taxol细胞株紫杉醇耐药

BACKGROUND AND OBJECTIVE: Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis.β-tubulin is the main cell targets of anti-microtubule drug.Increased expression of βⅢ-tubulin has been implicated in non-small cell lung cancer (NSCLC) cell lines.To explore the relationship among the expression level of βⅢ-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition of βⅢ-tubulin in A549/Taxol cells. METHODS: Three pairs of siRNA targetd βⅢ-tubulin were designed and prepared, which were transfected into A549/Taxol cells using Lipofectamine(TM) 2000.We detected the expression of βⅢ-tubulin mRNA using Real-time fluorescence qRT-PCR.Tedhen we selected the most efficient siRNA by the expression of βⅢ-tubulin mRNA in transfected group.βⅢ-tubulin protein level were mesured by Western blot.The taxol sensitivity in transfected group were evaluated by MTT assay.And the cell apoptosis and cell cycles were determined by flow cytometry. RESULTS: βⅢ-tubulin mRNA levels in A549/Taxol cells were significantly decreased in transfected grop by Real-time qRT-PCR than control groups.And βⅢ-tubulin siRNA-1 sequence showed the highest transfection efficiency, which was (87.73±4.87)% (P < 0.01);Western blot results showed that the expressional level of BⅢ tublin protein was significantly down-reulated in the transfectant cells than thant in the control cells.By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60)% (P < 0.01).The early apoptosis rate of A549/Taxol cells in transfected group were significantly higher than that of control group (P < 0.01);G(2)/M content in taxol group obviously increased than untreated samples by the cell cycle (P < 0.05). CONCLUSION: βⅢ-tubulin down-regulated significantly sensitized NSCLC A549/Taxol cells to Paclitaxel.