[A study on selective killing effect of Hsv-tk/GCV driven by human telomerase catalytic subunit promoter on human lung cancer cell A549].
OBJECTIVE
To study selective killing effect of herpes simplex virus-thymidine kinase/ganciclovir (Hsv-tk/GCV) driven by human telomerase catalytic subunit (hTERT) promoter on lung cancer cell line A549 in vitro.


METHODS
(1) Expression plasmids of Hsv-tk gene driven by hTERT promoter and sv40 promoter respectively (pGL3-hTp-tk and pGL3-sv40-tk) were transfected into telomerase-positive human lung adenocarcinoma cell line A549 and telomerase-negative fetal lung fibroblast cell line MRC-5. Reverse transcription-PCR was performed to detect expression of tk gene in above transfected cell lines; (2) Inhibition effect on proliferation of above transfected cell lines treated with GCV was investigated with MTT method; (3) Influence of GCV on apoptosis and cell cycle of above transfected cell lines was investigated with flow cytometry.


RESULTS
(1) tk mRNA expression was detected in both A549 and MRC-5 transfected with pGL3-sv40-tk, also in A549 transfected with pGL3-hTp-tk, but not in pGL3-hTp-tk transfected MRC-5; (2) GCV showed significant inhibition effects on proliferation of pGL3-sv40-tk transfected A549 and MRC-5 in vitro, also on that of pGL3-hTp-tk transfected A549, but not on that of pGL3-hTp-tk transfected MRC-5; (3) Treated with GCV, apoptosis index (AI) of pGL3-sv40-tk transfected A549 and MRC-5 as well as pGL3-hTp-tk transfected A549 (21.58%, 9.35% and 23.19% respectively) increased significantly, compared with A549, MRC-5 transfected with pGL3-hTp (0.78% and 0.55% respectively) and A549, MRC-5 without plasmid transfection as blank control (2.17% and 0.60% respectively); GCV had no influence on AI of pGL3-hTp-tk transfected MRC-5 (0.88%).


CONCLUSIONS
tk gene driven by hTERT promoter could express selectively in lung cancer cell A549. Hsv-tk/GCV driven by hTERT promoter could selectively inhibit proliferation of lung cancer cell.
Tang
Xiao-jun
XJ
Department of Thoracocardiosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041 PR China.
Wang
Yan-ping
YP
Zhou
Qing-hua
QH
Che
Guo-wei
GW
Chen
Xiao-he
XH
Zhu
Da-xing
DX
D000998:Antiviral Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005434:Flow Cytometry; D015774:Ganciclovir / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy; D011401:Promoter Regions, Genetic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics; D019098:Telomerase / Q000235:genetics*; D013937:Thymidine Kinase / Q000235:genetics*; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics
D000998:Antiviral Agents; D014764:Viral Proteins; D013937:Thymidine Kinase; D019098:Telomerase; D015774:Ganciclovir