Galectin-3 stabilizes heterogeneous nuclear ribonucleoprotein Q to maintain proliferation of human colon cancer cells

Cell Mol Life Sci. 2009 Jan;66(2):350-64. doi: 10.1007/s00018-009-8562-3.

Abstract

Comparative analysis of proteomes using 5-fluorouracil (5-FU)-resistant human colon cancer cell line revealed that decreased galectin-3 expression was significantly associated with retarded proliferation. However, in the presence of 5-FU proliferation rate of cells with suppressed galectin-3 expression did not differ from that of cells with normal galectin-3 expression, even galectin-3 suppression augmented apoptosis. Mechanism by which galectin-3 regulates cancer cell proliferation has been identified in immunoprecipitates of the anti-galectin-3 antibody. Heterogeneous nuclear ribonucleoprotein Q (hnRNP Q) was identified as a protein interacting with galectin-3. Interestingly, while galectin-3 protein was not affected by the hnRNP Q level, its suppression was accompanied by a decrease in hnRNP Q expression. The present study demonstrates that galectin-3 stabilizes hnRNP Q via complex formation, and reduction in the hnRNP Q level leads to slow proliferation and less susceptibility to 5-FU.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Sequence
  • Antimetabolites / metabolism
  • Apoptosis / physiology
  • Cell Cycle Proteins
  • Cell Line, Tumor
  • Cell Proliferation*
  • Colonic Neoplasms / metabolism*
  • Colonic Neoplasms / pathology
  • Down-Regulation
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Fluorouracil / metabolism
  • Galectin 3 / genetics
  • Galectin 3 / metabolism*
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism*
  • Humans
  • Molecular Sequence Data
  • Phosphoproteins / metabolism
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism*
  • Protein Kinases / metabolism
  • Proteome / analysis
  • Ribosomal Protein S6 Kinases / metabolism
  • Signal Transduction / physiology
  • TOR Serine-Threonine Kinases

Substances

  • Adaptor Proteins, Signal Transducing
  • Antimetabolites
  • Cell Cycle Proteins
  • EIF4EBP1 protein, human
  • Galectin 3
  • Heterogeneous-Nuclear Ribonucleoproteins
  • Phosphoproteins
  • Protein Isoforms
  • Proteome
  • SYNCRIP protein, human
  • Protein Kinases
  • MTOR protein, human
  • Ribosomal Protein S6 Kinases
  • TOR Serine-Threonine Kinases
  • Extracellular Signal-Regulated MAP Kinases
  • Fluorouracil