title: siRNA directed against c-Myc inhibits proliferation and downregulates human telomerase reverse transcriptase in human colon cancer Colo 320 cells.
abstract: 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.
authors.affiliation: Center of Experimental Medicine, Wuhan No,1 Hospital, Wuhan, 430022, PR China. hao4@163.com
authors.forename: Huang
authors.initials: H
authors.lastname: Hao
authors.forename: Yu
authors.initials: Y
authors.lastname: Nancai
authors.forename: Fu
authors.initials: F
authors.lastname: Lei
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Su
authors.initials: S
authors.lastname: Wen
authors.forename: Huang
authors.initials: H
authors.lastname: Guofu
authors.forename: Wu
authors.initials: W
authors.lastname: Yanxia
authors.forename: Huang
authors.initials: H
authors.lastname: Hanju
authors.forename: Liu
authors.initials: L
authors.lastname: Qian
authors.forename: Xiao
authors.initials: X
authors.lastname: Hong
mesh_terms: 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
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D034741:RNA, Small Interfering; D019098:Telomerase