RESUMEN
Objective To study the effect of telomere seeding on the biological behaviors of gastric cancer cell line and its mechanism. Methods The plasmid pSXneo-1.6-T2AG3, containing telomere fragment, was prepared in large scale and transfected into gastric cancer cell line SGC-7901 by LipofectAMINTM 2000. G418 was used to scan the positive clones and PCR was preformed to verify the stable seeding of the exogenous telomere in cell. MTT aassay and flow cytometry were used to determine the growth and cycle distribution of cells. The expression of cell cycle-related genes was detected by RT-PCR. Results Both pSXneo-1.6-T2AG3 eukaryonic expressing vector be inserted with telomere TTAGGG fragments and control vector were transfected into gastric cancer cell line SGC-7901 with LipofectamineTM 2000 and gain clones through G418 selection respectively, which were named as SGC-7901-telo and SGC-7901-neo. The cells were examined on DNA level by PCR to determine the correction of transfection. Flow cytometric analysis displayed an accumulation in G1M and G2M phase of cell cycle and an decreased percentage in S phase and proliferative index. Expression of p21 mRNA in 7901-telo cell line was increased (P0.05). Conclusion The pSX-T2AG3-neo eukaryonic expressing vector be inserted with 1600bp telomere TTAGGG fragments was successfully transfected into gastric cancer cell line SGC-7901 with the help of LipofectamineTM 2000. The seeding decreased malignant phenotypes of gastric cancer cell line and up-regulated the expression of p21, but the seeding did not distinctly influence on caspase3 mRNA expression.