粉防己碱逆转大肠癌耐药细胞株LOVO／5-Fu多药耐药性的实验研究

Reversal of multidrug resistance in human colon carcinoma LOVO/5-Fu cells by tetrandrine

目的探讨粉防己碱（tetrandrine，Tet）逆转人大肠癌多药耐药细胞LOVO／5-Fu的多药耐药性（muhidrugresistance，MDR）及其机制。方法Tet作用于LOVO／5-Fu细胞48h后，用噻唑蓝法检测LOVO／5-Fu细胞耐药性，流式细胞术检测细胞凋亡、周期变化及其P-糖蛋白（P-glycoprotein，P-gP）的表达水平，实时荧光定量PCR检测各组细胞MDR1mRNA表达水平，Westernblot检测各组细胞P-gP蛋白的表达水平。结果经过Tet作用48h后，大肠癌LOVO／5-Fu细胞株的IC50降低为（4．15±0．31）μg／ml（P〈0．05），细胞凋亡率增加为（3．44％±0．28％）（P〈0．05），MDR1 mRNA转录水平降低为（570±85）（P〈0．05），P-gP的表达水平下降。结论Tet能逆转大肠癌多药耐药细胞LOVO／5-Fu的MDR，其机制可能是抑制MDR1基因的表达，使P-gP的表达降低，从而增强了LOVO／5-Fu细胞对5-Fu的敏感性。

Objective To explore the reversal effect on MDR1 gene-mediated multidrug resistance in human colon carcinoma LOVO/5-Fu ceils by tetrandrine（Tet） and to clarify its molecular mechanism. Methods LOVO/5-Fu cells were treated for 48 h with Tet. Drug sensitivity was measured by MTT. The cell cycle, apoptosis of cells and expression of P-glycoproteiu （P-gp） were determined by flow cytometry assay. Expression of MDR1 mRNA was detected by real-time quantitative PCR （real-time PCR）. P-gp expression was detected by Western blot. Results After LOVO/5-Fu cells were treated for 48 h with Tet, the IC50 of 5-Fu decreased to （4. 15 ±0. 31 ） μg/ml （P 〈 0. 05 ）; and the apoptotic rate increased to （3.44% ± 0. 28% ） （ P 〈 0. 05 ） ; the expression of MDR1 mRNA reduced to （ 570± 85 ） （ P 〈 0. 05 ）. Conclusions Tetrandrine reverses MDR1 gene-mediated muhidrug resistance in human colon carcinoma LOVO/5-Fu cells possibly by inhibiting the expression of MDR1, decreasing the expression of P-gp, thus enhancing the sensitivity of LOVO/5-Fu cells to 5-fluorouracil.