Exogenous wild-type p16INK4A gene induces delayed cell proliferation and promotes chemosensitivity through decreased pRB and increased E2F-1 expressions.
Human gastric cancer SNU 484 cells express mutant p16, which migrates slower than the wild-type p16. We constructed an expression vector containing human p16 cDNA to evaluate the cytotoxic effects of exogenous p16 expression on SNU 484 cell proliferation and to explore the potential use of p16 in cancer gene therapy. The stable transfectant expressing wild-type p16, showed a 2-fold slower growth rate than mock and non-infected cells through down-regulation of CDK4-dependent kinase activity. When cells were transiently transfected with mock or p16 encoded vector, the mock cells showed larger survival colonies than those of wild-type p16. Furthermore, p16-expressing stable transfectant was readily progressed into cell death by combination with treatment of chemotherapeutic drug in a dose-dependent manner. According to western blot analysis, both decreased expression of pRB and increased expression of E2F-1 may contribute to the susceptibility of cell death. Our data indicate that exogenous wild-type p16 induces delayed cell proliferation and promotes chemo-sensitivity in the gastric cancer cell line, implying the promise of p16 in cancer gene therapy.
Jeong
Yong-Wook
YW
Department of Microbiology, College of Medicine, Seonam University, Namwon, Chunpook 590-711, Republic of Korea.
Kim
Ki-Sung
KS
Oh
Jae-Young
JY
Park
Jong-Chun
JC
Baek
Won-Ki
WK
Suh
Seong-Il
SI
Suh
Min-Ho
MH
Lee
Je-Chul
JC
Cho
Jae-We
JW
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000235:genetics*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D005047:Etoposide / Q000494:pharmacology; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D016160:Retinoblastoma Protein / Q000096:biosynthesis / Q000235:genetics*; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
D000964:Antimetabolites, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; D018797:Cell Cycle Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D016160:Retinoblastoma Protein; D014157:Transcription Factors; D005047:Etoposide; D005472:Fluorouracil