论文部分内容阅读
目的探讨甲基转移酶抑制剂5-氮杂-2’-脱氧胞苷(5-aza-dC)对结肠癌奥沙利铂(L-OHP)耐药细胞株sw620/L-OHP耐药性的逆转作用及其作用机制。方法应用5-aza-dC作用于结肠癌细胞sw620与其L-OHP耐药细胞sw620/L-OHP,CCK-8法检测其逆转耐药作用;应用Westernblot检测5-aza-dC使用前后sw620/L-OHP细胞中BNIP3基因及耐药基因编码的P糖蛋白(P-GP)、多药耐药相关蛋白(MRP)表达水平的变化;应用同位素微量示踪法检测5-aza-dC使用前后sw620/L-OHP细胞中甲基转移酶(DNMT)的活性。结果 1.4μmol/L5-aza-dC能使L-OHP对sw620/L-OHP细胞IC50由(0.335±0.043)μg/mL降到(0.069±0.023)μg/mL,逆转耐药倍数为8.26倍(P<0.001);5-aza-dC能使sw620/L-OHP细胞中P-GP、MRP蛋白表达增加(P<0.05),但增加程度与5-aza-dC剂量变化无关(P>0.05);另外5-aza-dC还能使表达低下的BNIP3蛋白重新表达,且其表达水平随5-aza-dC浓度的增加而增加(P<0.001);5-aza-dC能够降低sw620/L-OHP细胞中DNMT的活性(P<0.001)。结论 5-aza-dC通过降低DNMT活性来上调BNIP3的表达,并协同某种机制抑制P-GP、MRP的进一步表达,从而逆转sw620/L-OHP细胞耐药性。
Objective To investigate the drug resistance of 5-aza-2’-deoxycytidine (5-aza-dC), a methyltransferase inhibitor, to sw620 / L-OHP resistant human colon cancer oxaliplatin- The reversal effect and its mechanism of action. Methods The effects of 5-aza-dC on sw620 / L-OHP and L-OHP-resistant cells in SW620 / L-OHP cells were detected by CCK-8 assay. Western blot was used to detect the expression of sw620 / (P-GP) and multidrug resistance-associated protein (MRP) expression of BNIP3 gene and drug resistance gene in the -OHP cells. The levels of sw620 / L-OHP cells in methyltransferase (DNMT) activity. Results IC50 of L-OHP decreased from (0.335 ± 0.043) μg / mL to (0.069 ± 0.023) μg / mL for SW620 / L-OHP cells and the reversal of drug resistance was 8.26-fold (P <0.001). The expression of P-GP and MRP in sw620 / L-OHP cells was increased by 5-aza-dC, but the increase was not related to the dose of 5-aza- In addition, 5-aza-dC can also re-express low expression of BNIP3 protein, and its expression level increased with the increase of 5-aza-dC concentration (P <0.001); 5-aza-dC can reduce sw620 / L- DNMT activity in OHP cells (P <0.001). Conclusions 5-aza-dC can up-regulate the expression of BNIP3 by decreasing the activity of DNMT and cooperate with some mechanism to inhibit the further expression of P-GP and MRP, thereby reversing the drug resistance of sw620 / L-OHP cells.