热疗联合 IL-2逆转人肺腺癌细胞 A549/CDDP 的作用及其可能机制

目的：观察热疗联合白介素-2（IL-2）对人肺腺癌细胞株 A549/ CDDP 的耐药逆转作用，并探讨其可能作用机制。方法采用细胞培养技术，分别培养人肺腺癌细胞株 A549及其耐药细胞株 A549/ CDDP。42℃热疗，联合或不联合200 u·mL -1的 IL-2，同时在2μg·mL -1的 CDDP 作用下，分别干预敏感细胞株和耐药细胞株2 h 后，采用 MTT 法检测2种不同细胞对 CDDP 的敏感性，流式细胞仪间接免疫荧光法检测热疗、IL-2等不同条件作用下细胞中 P -糖蛋白（P-gp）、多药耐药蛋白（MRP）、肺耐药蛋白（LRP）的表达差异，以及细胞内荧光药物 CDDP 的聚集量的变化。结果分别联用热疗、IL-2时，较单用 CDDP，A549/ CDDP细胞的抑制率得到提高，A549/ CDDP 细胞 P-gp、MRP 表达下降，细胞内荧光强度增强，差异均有统计学意义（P 均﹤0.05）。热疗联合 IL-2合用 CDDP 时，A549/ CDDP 细胞的抑制率进一步提高，A549/ CDDP 细胞P-gp、MRP 表达明显下降，细胞内荧光强度显著增强，差异均有统计学意义（P 均﹤0.05），但 LRP 的表达差异无统计学意义（P ﹥0.05）。结论热疗、IL-2分别能部分逆转 A549/ CDDP 细胞对 CDDP 的耐药性；热疗联合 IL-2可进一步增强其耐药逆转效应。其逆转耐药机制，推测可能与抑制 P-gp、MRP 表达，增加细胞内药物 CDDP 的积聚有关。

Effect and Possible Mechanism of Thermotherapy Combined with IL-2 on Reversing the Drug Resistance of the Human Lung Adenocarcinoma Cell Line A549/CDDP

Objective To observe the reversal effect of thermotheapy combined with interleukin-2(IL-2)on the drug resistance of human lung adenocarcinoma cell line A549 / CDDP,and to explore its possible mechanism. Meth-ods Human lung adenocarcinoma cell line A549 and its drug resistant cell line A549 / CDDP were cultured by cell culture technique. After under the thermotherapy of 42 ℃,combined or not combined with 200 u·mL - 1 of IL-2, and 2μg·mL - 1 of CDDP,A549 and A549 / CDDP were intervented for 2 hours. The MTT assay was used to detect the sensitivity of cell line A549 and the cell line A549 / CDDP to CDDP,respectively. Flow cytometry detection were also employed to determine the P-glycoprotein(P-gp),multidrug resistance protein(MRP),lung resistance pro-tein(LRP)differential expression and CDDP intracellular fluorescence concentration changes in A549 cell line and A549 / CDDP cell line before and after the combined treatment,respectively. Results With thermotherapy or IL-2, the inhibition rate of CDDP to A549 / CDDP cell line was higher than with CDDP only used,the positive expression rate of p-gp and MRP of A549 / CDDP cells decreased,and the intracellular accumulation of CDDP increased,the differences were statistically significant(P ﹤ 0. 05). Thermotherapy combined with IL-2 could further reverse the drug resistance of A549 / CDDP cell line,the positive expression rate of P-gp and MRP significantly decreased,and the accumulation of intracellular CDDP increased more significantly(P ﹤ 0. 05). But there was no significant differ-ence for the expression of LRP(P ﹥ 0. 05). Conclusion Thermotherapy and IL-2 can partly reverse the drug re-sistance of human lung adenocarcinoma cell line A549 / CDDP to CDDP,and thermotherapy combined with IL-2 can further enhance its reversal effect of drug resistance. The mechanism of reversing drug resistance ,presumably,re-lated to inhibition of p-gp,MRP expression,and to increased intracellular accumulation of CDDP.