title: Depletion of c-Myc inhibits human colon cancer colo 320 cells' growth.
abstract: Human colon cancer is the leading cause of cancer death in both men and women worldwide. The c-Myc gene is frequently deregulated and overexpressed in this malignancy, and strategies designed to inhibit c-Myc expression in cancer cells may have considerable therapeutic value. We design and use short hairpin RNA (shRNA) to inhibit c-Myc expression in Colo 320 cells and validat its effect on cell proliferation. In this study, four c-Myc-shRNA expression vectors were constructed and introduced into Colo 320 cells, and the cell cycle and apoptotic cells were analyzed by flow cytometry. The effects of c-Myc silencing on tumor-cell growth was assessed by the soft agar assay and by DNA synthesis experiments. Expression of c-Myc was 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 decreased in shRNA-transfected cells, and the downregulation of c-Myc inhibited cell growth and induced apoptosis in Colo 320 cells. c-Myc downregulation also increased cell population in the G0-G1 phase. In conclusion, our findings demonstrate that shRNA can inhibit the DNA replication and induce apoptosis in Colo 320 cells effectively and, therefore, could be used as a new potential anticancer tool for the therapy of human colon cancer.
authors.affiliation: Center of Experimental Medicine, Wuhan First Hospital, Wuhan City, People's Republic of China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Hongxing
authors.forename: Yu
authors.initials: Y
authors.lastname: Nancai
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: Ma
authors.initials: M
authors.lastname: Wei
authors.forename: Yi
authors.initials: Y
authors.lastname: Yandong
authors.forename: Huang
authors.initials: H
authors.lastname: Hao
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology* / Q000628:therapy; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D016271:Proto-Oncogene Proteins c-myc / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference
chemical_list: D016271:Proto-Oncogene Proteins c-myc