Effects of HIF-1α expression regulated by Tet-on gone expression system on hepatoma cell proliferation and cell cycle in vitro / 中华普通外科杂志

Objective To investigate the effects of HIF-1α expression regulated by Tet-on gene expression system on cell proliferation and cell cycle of hepatoma cells in vitro. Methods The change of human hepatocellular carcinoma cell lines HepG2 cell cycle and cell proliferation was measured after HIF-1 α expression of HepG2 in vitro was regulated by Tet-on expression system. Results Amplified products were confirmed as the cDNA of HIF-1α by DNA sequencing, and pTRE-HIF-1α obtained by edonuclease digestion,capable of expression in HepG2 Tet-on cells. After being incubated under different concentrations of doxycycline for 48 h, MTT assays showed that up-regulation of HIF-1α expression increased HepG2 cell proliferation activities. The cell index of S and G2/M phase was significantly higher and that of G0/G1 phase reduced with the increasing concentrations of doxycycline. The mRNA expression of Cyclin A increased with the increasing concentrations of doxycycline ( P ＜ 0. 001 ), CyclinD1 and CyclinE did not change ( P ＞0. 05). Conclusion HIF-1 α gene promotes cell proliferation and cell cycle of hcpatoma cells in vitro, and this effects increased with the increasing of HIF-1α expression possibly through influencing the expression of CyclinA.

Tet Regulating Expression System Establishment and Functional Analysis ofNovel Gene STGC3 in Nasopharyngeal Carcionma Cell Line CNE2 / 生物化学与生物物理进展

In an attampt to establish the functional expression of STGC3 with doxycycline (Dox) induced Tet-onregulating system in human nasopharyngeal carcinoma cell line CNE2, an ideal experimental platform wasprovided for further studies of STGC3. pTet-on regulating plasmid was transfected into CNE2, and stableexpression of Tet-on was established in CNE2 through G418 select. Then the response plasmid of recombinantpTRE-STGC3 was steadily transfected into positive CNE2/Tet-on cells with hygromycin screen. Dox was used toinduce the expression of STGC3 and a cell clone sensitive to Dox was selected. The best-induced concentrationwas determined with different concentration of Dox induction. Growth curves, clone formation rate and cell cycledistribution were detected after STGC3 gene up-regulated expression with Dox induction. The growth capacity andclone formation potential of CNE2/Tet /pTRE-STGC3 was significantly suppressed, compared with the controls(P

The effect of Tet-on gene regulated HIF-1?expression on hepatoma cell apoptosis in vitro / 中国普通外科杂志

Objective To investigate the effects of Tet-on gene regulated HIF-1?expression on cell apoptosis of hepatoma cells in vitro. Methods The apoptosis of hepatocellular carcinoma cell lines HePG2 was measured after HIF-1?expression was activated in HePG2 in vitro by Tet-on expression system. Results The amplified products were confirmed as the cDNA of HIF-1?by DNA sequencing, and obtained pTHE-HIF-1?was verified by endonuclease digestion. The HePG2Tet-on cells express HIF-1?constantly. After being incubated under different concentrations of doxycycline for 48 h, HIF-1?gene could inhibit HePG2 cell apoptosis. The apoptosis rates were 59. 6%、50. 9%、38. 1%、30. 5%、23. 9%、18. 3% respectively when the concentrations of doxycycline were 0?g/ml,0. 02?g/ml,0. 2?g/ml、1?g/ml、2?g/ml,5?g/ml (P