缺氧时三氧化二砷对人肝癌细胞株BEL-7402生长及凋亡的影响及机制

Effects and mechanism of arsenic trioxide on growth and apoptosis of the human liver cancer cell line BEL-7402 during hypoxia

目的:探讨不同浓度三氧化二砷(As_2O_3)对人肝癌细胞株BEL-7402生长及凋亡的影响及机制.方法:应用化学缺氧剂二氯化钴(CoCl_2)诱导人肝癌细胞BEL-7402缺氧.不同浓度As_2O_3对BEL-7402进行干预后,应用MTT法测定缺氧条件下的生长抑制作用:应用电镜,激光共聚焦显微镜及流式细胞术观察其对细胞凋亡的影响;应用逆转录聚合酶链式反应检测缺氧诱导因子HIF-1α,耐药基因mdrl的表达水平.结果:As_2O_3具有抑制人肝癌细胞株BEL-7402缺氧条件下生长的作用,并呈剂量-效应依赖性;4.0μmol/L AS_2O_3干预48h后,缺氧条件下的细胞呈现典型的凋亡形态学特征;缺氧时,0.5-4.0μmol/L As_2O_3下调HIF-1α,mdrl基因表达水平,其中4.0μmol/L AS_2O_3组作用最强,基因相对表达量分别为HIF-1α0.60±0.07,mdrl 0.59±0.09.各剂量组As_2O_3作用后与缺氧对照组比较差异有显著性(P<0.01).结论:不同浓度的As_2O_3在由CoCl_2诱导的化学缺氧奈件下能够抑制人肝癌细胞BEL-7402的生长及诱导凋亡,其机制可能与As_2O3下调HIF-1α、mdrl的基因表达水平有关.

AIM： To investigate the effects of arsenic trioxide （As203） on apoptosis and migration of the human liver cancer cell BEL-7402 under normal and hypoxic conditions. METHODS： A hypoxic environment was induced by CoCl2. The effect of As2O3 was determined by MTT assay. Electron microscopy, laser scanning confocal microscopy and flow cytometry （FCM） were used to study apoptosis of the human liver cancer cell BEL-7402. Expression of the multidrug resistance 1 （mdrl） and Hypoxia- inducible-factor-1α （HIF-1α） genes was detected by reverse transcriptase-polymerase chain reaction. RESULTS： Different concentrations of As2O3 can inhibit growth and induce apoptosis of the human liver cancer cell BEL-7402 during hypoxia. After being induced by 4.0μmol/L As203 for 48 hours in hypoxia, the BEL-7402 cell had morphological features of apoptosis as observed by electron and laser scanning confocal microscopies. Concentrations of 0.5-4.0 μmol/L As2O3 down-regulated the mRNA expression of HIF- 1α and mdrl under hypoxic conditions, with the strongest effect being from 4.0μmol/L. The mRNA contents of HIF-1α and mdrl treated with 4.0 μmol/L As203 for 48 hours under hypoxic conditions were 0.60 ± 0.07 and 0.59±0.09, respectively. This was significantly different compared with the hypoxia control group （P 〈 0.01）. CONCLUSION： As2O3 inhibited growth and induced apoptosis in the human liver cancer cell line BEL-7402 during hypoxia. The mechanism probably was related to the inhibition of the ex- pressions of HIF-1α and mdrl.