HIFU逆转人肝癌细胞HepG2/Adm多药耐药的实验研究

背景与目的：超声波能够改变细胞膜通透性,增强化疗药物对肿瘤细胞的杀伤作用。本研究评价高强度聚焦超声及其联合阿霉素(Adriamycin,ADM)对人肝癌多药耐药细胞株HepG2／Adm的效应,并探讨其作用机制。方法：取对数生长期的HepG2、HepG2／Adm细胞进行实验,分为HepG2、HepG2(超声波照射5s)、HepG2／Adm、HepG2／Adm(超声波照射5s)4组。用MTT法检测处理前后耐药细胞对抗癌药物的敏感性;用流式细胞仪检测肿瘤细胞表面mdr1基因表达产物P170的表达及细胞内阿霉素浓度;利用SP免疫组化法观察细胞膜及核膜上P-糖蛋白(P-glycoprotein,P-gp)的表达。结果：频率0.8MHz、焦域声强460W／(cm^2连续照射5s,能够部分逆转HepG2／Adm细胞的耐药性,HepG2／Adm细胞P-gp的表达活性下降83．1％,耐药细胞内ADM浓度增加88％,对ADM、cDDP、MMc、5-FU和MTX相对逆转效率分别为66．4％、63．4％、89．4％、72．4％和75．0％。结论：高强度聚焦超声可提高人肝癌细胞HepG2／Adm内药物浓度,降低细胞膜及核膜表面P-gp表达,从而部分逆转肿瘤细胞多药耐药。

Reversal of multidrug resistance of human hepatocarcinoma HepG2/Adm cells by high intensity focused ultrasound

BACKGROUND &OBJECTIVE: The effects of ultrasound have been show n on increasing cell membrane permeability and thereby might promote cellular upta ke of cytotoxic drugs and enhance chemotoxicity. The aim of this study was to ex amine the reversal effects of high intensity focused ultrasound (HIFU) and co-a dministration with Adriamycin (ADM) on multidrug resistance (MDR) in HepG2/Adm c ells, and to investigate its mechanism. METHODS: HepG2 cells and HepG2/Adm cells were divided into 4 groups: HepG2 (control group),HepG2 (treated with HIFU 5s), HepG2/Adm (non HIFU), and HepG2/Adm (treated with HIFU 5s). MTT assay was used t o examine the chemosensitivity to ADM in HIFU-treated HepG2 and HepG2/Adm cell lines. Before and after the treatment with HIFU 5s, MDR1 gene expression was det ermined by immunocytochemistry assay. Flow cytometry was used to determine intra cellular ADM concentration and the expression of P-gp on cell membranes. RESULT S: HIFU (0.8MHz, 460W/cm2) partly overcame the MDR of cell line HepG2/Adm and de creased the drug resistance. The relative reverse efficiencies to ADM, cisplatin (DDP), mytomycin (MMC), 5-fluorouracil (5-FU), and methotrexate (MTX) were 66 .4%, 63.4%, 89.4%, 72.4%, and 75.0%, respectively. While, the concentration of ADM in HepG2/Adm cells was increased by 88%. The expression of P-glycoprot ein (P-gp) protein in HepG2/Adm was down-regulated by 83.1%. CONCLUSION: HIFU can not only increase the ADM concentration in HepG2/Adm cells and decrease P- gp expression on cellular and nuclear membrane, but also partly overcome MDR of tumor cells.