Telomere position effect in gastric cancer cell SGC7901 / 第三军医大学学报

ABSTRACT

Objective To determine the possibility of telomere seeding in human gastric cancer cell SGC7901 and the influence of telomere on the expression of luciferase reporter gene nearby and to explore the position effect of telomere in gastric cancer cell. Methods The TET-OFF regulatory system was prepared and then transfected to gastric cancer cell SGC7901 by Lipofectamine TM 2000. With doxycycline added, the activity of the fluorescence caused by the expression of the target gene (the luciferase gene) with TET-OFF regulatory system was analyzed. The luciferase reporter plasmid in which telomere fragment pBX was inserted and the control plasmid pBX-ntf (no teloemere fragment) were co-transfected to cell 7901 with pTET-OFF regulate plasmid respectively and the luciferase activity was determined with doxycycline's induction. Results With the inducing of Dox, the activity of the fluorescence caused by the expression of the luciferase gene was inhibited. Treated with deoxycyline, there was a 4-fold decrease in the activity of the fluorescence in the cells infected with pBX and pTET-OFF as compared with that in the cells infected with pBX-ntf and pTET-OFF. Conclusion With the help of Lipofect2000, the gastric cancer cell SGC7901 can be transfected by TET-OFF regulatory system successfully. Dox could repress luciferase gene expression. Telomere seeding in gastric cancer cell SGC7901 could decrease the expression of luciferase reporter gene.