Effect of antisense c-raf-1 on tumorigenicity and radiation sensitivity of a human squamous carcinoma.
Antisense RNA-mediated inhibition of gene expression was used to investigate the biological function of the c-raf-1 gene in a radiation-resistant human squamous carcinoma cell line, SQ-20B. S1 nuclease protection assays revealed that transfection of full-length raf complementary DNA in the antisense orientation (AS) leads to a specific reduction (greater than tenfold) of steady-state levels of the endogenous c-raf-1 sense (S) transcript in SQ-20B cells. In nude mice, the malignant potential of SQ-20B cells transfected with raf (S) was significantly increased relative to that of SQ-20B cells transfected with raf (AS). SQ-20B cells containing transfected raf (S) maintained a radiation-resistant phenotype as compared to those cells harboring the AS version, which appeared to have enhanced radiation sensitivity. These data indicate that the reduced expression of endogenous c-raf-1 is sufficient to modulate the tumorigenicity and the radiation-resistant phenotype of SQ-20B cells, thus implicating c-raf-1 in a pathway important to the genesis of this type of cancer.
Kasid
U
U
Department of Radiation Medicine, Vincent T. Lombardi Comprehensive Cancer Research Center, Georgetown University Medical Center, Washington 20007.
Pfeifer
A
A
Brennan
T
T
Beckett
M
M
Weichselbaum
R R
RR
Dritschilo
A
A
Mark
G E
GE
D000818:Animals; D015139:Blotting, Southern; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D002999:Clone Cells; D004307:Dose-Response Relationship, Radiation; D005786:Gene Expression Regulation; D006801:Humans; D007700:Kinetics; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009693:Nucleic Acid Hybridization; D011519:Proto-Oncogenes; D012313:RNA / Q000235:genetics*; D016372:RNA, Antisense; D012333:RNA, Messenger / Q000037:antagonists & inhibitors*; D014158:Transcription, Genetic; D014162:Transfection; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured / Q000528:radiation effects*
D016372:RNA, Antisense; D012333:RNA, Messenger; D012313:RNA