超表达蛋白激酶B对SMMC 7721肝癌细胞增殖和凋亡的影响

采用脂质体转染的方法 ,将含持续激活蛋白激酶B的真核表达质粒转染到SMMC 772 1肝癌细胞中 ,研究蛋白激酶B对人肝癌细胞增殖和凋亡的影响 .用RNA印迹及蛋白激酶B测活鉴定 ,并获得稳定表达持续激活蛋白激酶B的细胞株 ,用MTT法、软琼脂克隆形成率及细胞周期测定等方法检测超表达蛋白激酶B的 772 1细胞增殖情况 ,结果显示超表达蛋白激酶B的 772 1细胞生长能力增强 ,软琼脂克隆形成率增高 ,S期细胞增多 ,p2 7Kip1表达下降 .用流式细胞术检测悬浮培养诱导的细胞失巢凋亡 ,发现超表达蛋白激酶B能抑制细胞失巢凋亡 .上述结果提示蛋白激酶B能促进肝癌细胞增殖 ,抑制细胞凋亡 .

Influence of Over-expressing Protein Kinase B on Proliferation and Apoptosis of Human Hepatocellular Carcinoma SMMC 7721 Cells

The protein kinase B (PKB/Akt) is found over- expression in many kinds of cancer. Here Lipofectamin was used to transfect a consistent active form of PKB (gagPKB) into SMMC 7721 cells to study the ability of the influence of this protein on proliferation and apoptosis of human hepatocellular carcinoma SMMC 7721 cells. The stably over expressing PKB/Akt cell line was identified by Northern blot, Western blot and the assay of PKB activity. Over expressing PKB/Akt promoted cell growth in serum culture and anchorage- indpendent growth in agarose with high efficiency. Alternatively, over- expressing PKB/Akt was sufficient to promote the cells into the S phase of the cell cycle and decreased the expression of the cyclin- dependent kinase inhibitor p27 Kip1 . Furthermore, over- expression of PKB/Akt suppressed the apoptosis of cells induced by the detachment of the cells from extracelluar matrix. These results suggest the ability of PKB/Akt to promote proliferation and suppress apoptosis in cancer cells.