Suppression of the tumorigenicity of mutant p53-transformed rat embryo fibroblasts through expression of a newly cloned rat nonmuscle myosin heavy chain-B

Oncogene. 2001 Jan 4;20(1):58-68. doi: 10.1038/sj.onc.1203982.

Abstract

In our previous study, a rat homolog of human nonmuscle myosin heavy chain-B (nmMHC-B) was identified by mRNA differential display comparing of transformed against nontransformed Rat 6 cells overexpressing mutant p53val135 gene. The nmMHC-B was found to be expressed in normal Rat 6 embryo fibroblast cell line, but markedly suppressed in the mutant p53val135-transformed Rat 6 cells. To examine the possible involvement of nmMHC-B in cell transformation, we first cloned and sequenced the full length cDNA of rat nmMHC-B, which was then cloned into an ecdysone-expression vector. The resulting construct was introduced into the T2 cell line, a mutant p53val135-transformed Rat 6 cells lacking the expression of the endogenous nmMHC-B. The clonal transfectants, expressing muristerone A-induced nmMHC-B, displayed a slightly flatter morphology and reached to a lower saturation density compared to the parental transformed cells. Reconstitution of actin filamental bundles was also clearly seen in cells overexpressing the nmMHC-B. In soft agar assays, nmMHC-B transfectants formed fewer and substantially smaller colonies than the parental cells in response to muristerone A induction. Moreover, it was strikingly effective in suppressing the tumorigenicity of the T2 cells when tested in nude mice. Thus, the nmMHC-B, known as a component of the cytoskeletal network, may act as a tumor suppressor gene. Our current finding may reveal a novel role of nmMHC-B in regulating cell growth and cell signaling in nonmuscle cells. Oncogene (2001) 20, 58 - 68.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Amino Acid Sequence
  • Animals
  • Antineoplastic Agents / metabolism
  • Antineoplastic Agents / pharmacology
  • Cell Adhesion / genetics
  • Cell Count
  • Cell Line, Transformed
  • Cell Transformation, Neoplastic / genetics*
  • Cell Transformation, Neoplastic / pathology
  • Cloning, Molecular
  • DNA, Complementary / isolation & purification
  • Embryo, Mammalian
  • Fibroblasts / metabolism*
  • Fibroblasts / pathology
  • Fluorescent Antibody Technique, Indirect
  • Gene Expression Regulation, Neoplastic*
  • Genes, p53*
  • Genetic Vectors / biosynthesis
  • Genetic Vectors / chemical synthesis
  • Growth Inhibitors / biosynthesis
  • Growth Inhibitors / genetics
  • Growth Inhibitors / physiology
  • Humans
  • Mice
  • Mice, Nude
  • Molecular Motor Proteins*
  • Molecular Sequence Data
  • Mutation*
  • Myosin Heavy Chains / antagonists & inhibitors
  • Myosin Heavy Chains / biosynthesis*
  • Myosin Heavy Chains / genetics*
  • Myosin Heavy Chains / physiology
  • Nonmuscle Myosin Type IIB
  • Protein Isoforms / antagonists & inhibitors
  • Protein Isoforms / biosynthesis
  • Protein Isoforms / genetics
  • Rats
  • Transfection

Substances

  • Actins
  • Antineoplastic Agents
  • DNA, Complementary
  • Growth Inhibitors
  • MYH9 protein, human
  • Molecular Motor Proteins
  • Myh9 protein, rat
  • Protein Isoforms
  • Nonmuscle Myosin Type IIB
  • nonmuscle myosin type IIB heavy chain
  • Myosin Heavy Chains