siRNA directed against c-Myc inhibits proliferation and downregulates human telomerase reverse transcriptase in human colon cancer Colo 320 cells.
The c-Myc and human telomerase reverse transcriptase gene (hTERT) gene are frequently deregulated and overexpressed in malignancy. hTERT activity is induced by c-Myc and strategies designed to inhibit c-Myc expression in cancer cells may have considerable therapeutic value. We designed and used a short hairpin RNA to inhibit c-Myc expression in Colo 320 cells and validated its effect on cell proliferation. In this study, four c-Myc-shRNA expression vectors were constructed and introduced into Colo 320 cells. The effects of c-Myc silencing on tumor cell growth was assessed by soft agar assay and DNA synthesis experiments. The expressions of c-Myc and hTERT were also assessed by real-time reverse transcription-polymerase chain reaction and Western blot analysis. Upon transient transfection with plasmid encoding shRNA, it was found that expression of c-Myc and hTERT decreased in shRNA-transfected cells. The downregulation of c-Myc and hTERT inhibited cell growth, shortened telomere lengths, and suppressed telomerase activity. In conclusion, our findings demonstrate that shRNA of c-Myc can inhibit the DNA replication in Colo 320 cells effectively and reduce telomere length and telomerase activity, therefore, it could be used as a new potential anticancer tool for therapy of human colon cancer.
Hao
Huang
H
Center of Experimental Medicine, Wuhan No,1 Hospital, Wuhan, 430022, PR China. hao4@163.com
Nancai
Yu
Y
Lei
Fu
F
Xiong
Wei
W
Wen
Su
S
Guofu
Huang
H
Yanxia
Wu
W
Hanju
Huang
H
Qian
Liu
L
Hong
Xiao
X
D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015536:Down-Regulation; D006801:Humans; D016271:Proto-Oncogene Proteins c-myc / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism; D016615:Telomere / Q000378:metabolism; D014162:Transfection
D016271:Proto-Oncogene Proteins c-myc; D034741:RNA, Small Interfering; D019098:Telomerase