title: The other side of the coin: the tumor-suppressive aspect of oncogenes and the oncogenic aspect of tumor-suppressive genes, such as those along the CCND-CDK4/6-RB axis.
abstract: Although cancer-regulatory genes are dichotomized to oncogenes and tumor-suppressor gene s, in reality they can be oncogenic in one situation but tumor-suppressive in another. This dual-function nature, which sometimes hampers our understanding of tumor biology, has several manifestations: (1) Most canonically defined genes have multiple mRNAs, regulatory RNAs, protein isoforms, and posttranslational modifications; (2) Genes may interact at different levels, such as by forming chimeric RNAs or by forming different protein complexes; (3) Increased levels of tumor-suppressive genes in normal cells drive proliferation of cancer progenitor cells in the same organ or tissue by imposing compensatory proliferation pressure, which presents the dual-function nature as a cell-cell interaction. All these manifestations of dual functions can find examples in the genes along the CCND-CDK4/6-RB axis. The dual-function nature also underlies the heterogeneity of cancer cells. Gene-targeting chemotherapies, including that targets CDK4, are effective to some cancer cells but in the meantime may promote growth or progression of some others in the same patient. Redefining "gene" by considering each mRNA, regulatory RNA, protein isoform, and posttranslational modification from the same genomic locus as a "gene" may help in better understanding tumor biology and better selecting targets for different sub-populations of cancer cells in individual patients for personalized therapy.
authors.affiliation: CAS Key Laboratory of Genome Sciences and Information; Beijing Institute of Genomics; Chinese Academy of Sciences; Beijing, PR China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Lou
authors.affiliation: CAS Key Laboratory of Genome Sciences and Information; Beijing Institute of Genomics; Chinese Academy of Sciences; Beijing, PR China.
authors.forename: Ju
authors.initials: J
authors.lastname: Zhang
authors.affiliation: CAS Key Laboratory of Genome Sciences and Information; Beijing Institute of Genomics; Chinese Academy of Sciences; Beijing, PR China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Liu
authors.affiliation: Laboratory of Cell and Molecular Biology; Cancer Institute; Chinese Academy of Medical Science; Beijing, PR China.
authors.forename: Ningzhi
authors.initials: N
authors.lastname: Xu
authors.affiliation: Hormel Institute; University of Minnesota; Austin, MN USA.
authors.forename: D Joshua
authors.initials: DJ
authors.lastname: Liao
mesh_terms: D049109:Cell Proliferation / Q000235:genetics* / Q000502:physiology; D019938:Cyclin D1 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods; D016147:Genes, Tumor Suppressor / Q000502:physiology*; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D009857:Oncogenes / Q000235:genetics / Q000502:physiology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D038621:Regulatory Sequences, Ribonucleic Acid / Q000235:genetics*; D016160:Retinoblastoma Protein / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D038621:Regulatory Sequences, Ribonucleic Acid; D016160:Retinoblastoma Protein; D019938:Cyclin D1; D051358:Cyclin-Dependent Kinase 4
keywords: CDK4; cyclin D1; oncogenes; radiation therapy; targeted chemotherapy; tumor-suppressor gene s