【摘要】 目的研究腺苷及其代谢途径对人肝癌HepG2细胞凋亡的诱导作用及其机制。方法将腺苷2.0mmol.L-1作用于HepG2细胞24和48h,采用流式细胞术(FCM)测定细胞周期及凋亡率;观察腺苷膜转运体抑制剂双嘧达莫、腺苷脱氨酶抑制剂红-9-(2-羟基-3-壬烷基)腺嘌呤(EHNA)和腺苷激酶抑制剂5′-氨基5′-脱氧腺苷(AMDA)对腺苷抑制细胞存活的影响,应用MTT法测定细胞存活率;应用Western蛋白印迹法检测P53和Bcl-2蛋白的表达。结果腺苷与HepG2细胞作用24和48h,HepG2细胞出现特征性的亚二倍体凋亡峰,细胞凋亡百分率分别由对照组的(1.2±0.4)%和(4.1±1.6)%增加到(24.3±4.8)%和(38.6±7.4)%,细胞周期阻滞于G0/G1期。腺苷与HepG2细胞作用24h明显抑制细胞存活,P53表达明显增强,Bcl-2表达降低。预先分别给予双嘧达莫,AMDA和AMDA+双嘧达莫处理后,各处理组HepG2细胞存活率较腺苷组升高,细胞凋亡百分率和P53表达降低,Bcl-2表达无明显变化;EHNA预处理组细胞存活率、细胞凋亡百分率、P53和Bcl-2表达与腺苷组比较均无明显变化。结论腺苷可诱导HepG2细胞凋亡,腺苷在胞内可能通过腺苷激酶而不是通过转氨酶的代谢途径参与诱导细胞凋亡的过程。腺苷对HepG2细胞凋亡的诱导作用还可能与其增加P53蛋白表达有关。更多还原

【Abstract】 AIM To study the induction on apoptosis of adenosine in human hepatocellular carcinoma HepG2 cells and its mechanisms.METHODS HepG2 cells were incubated in vitro in the presence of adenosine 2.0 mmol·L-1 for 24 or 48 h,cell cycle and apoptosis were observed by using flow cytometry.The effects of dipyridamole(Dip,an inhibitor of adenosine transporter),erythro-9-(2-hydroxyl-3-nonyl)adenine(EHNA,an inhibitor of adenosine deaminase) and 5’-amino 5’-deoxyadenosine(AMDA,an inhibitor of adenosine kinase) on adenosine-induced apoptosis,cell survival and expressions of P53 and Bcl-2 were observed.Cell survival was evaluated with MTT assay.The protein expressions of P53 and Bcl-2 were assayed by using Western blot.RESULTS After HepG2 cells were incubated with adenosine for 24 or 48 h,the marked feature changes of cell apoptosis were observed,and cell apoptosis rates increased to(24.3±4.8)% and(38.6±7.4)% from(1.2±0.4)% and(4.1±1.6)% in control groups,respectively.Cell cycle was arrested in G0/G1 stages.In addition,the cell survival rate and Bcl-2 expression decreased and P53 expression increased 24 h after adenosine incubated with HepG2 cells.Compared with adenosine group,pretreatment with Dip,AMDA or Dip+AMDA significantly increased cell survival rate and decreased apoptosis rate and P53 expression,but not affected Bcl-2 expression.EHNA pretreatment had no effect on the above changes induced by adenosine.CONCLUSION Adenosine induces HepG2 cell apoptosis,which is relative to adenosine kinase other than adenosine deaminase pathway.The apoptosis induction of adenosine may also be related with its upregulating P53 expression.更多还原