TIMP1 induces CD44 expression and the activation and nuclear translocation of SHP1 during the late centrocyte/post-germinal center B cell differentiation

Cancer Lett. 2008 Sep 28;269(1):37-45. doi: 10.1016/j.canlet.2008.04.020. Epub 2008 May 23.

Abstract

Tissue inhibitor of metalloproteinase-1 (TIMP1) is a survival factor of germinal center (GC) B cells, and its over-expression is correlated with aggressive B cell lymphomas and classical Hodgkin lymphomas. We previously demonstrated that TIMP1 down-regulates B-cell receptor and BCL6, and activates interleukins-6,-10 (ILs)/signal transducer and activator of transcription-3 (STAT3) signaling in GC B cells. The activation of ILs/STAT3 signaling can amplify CD44 function, and vice versa, and induce protein-tyrosine phosphatase SHP1 activity by a negative feedback mechanism. Here, we show that TIMP1 up-regulates cell surface CD44 (standard and variants 3 and 7-10) and induces the activity and nuclear localization of SHP1 in an Epstein Barr virus (EBV)-negative Burkitt lymphoma cell line, the neoplastic counterpart of GC centroblasts. These results suggest that TIMP1 functions as a differentiating and survival factor of GC B cells by modulating CD44 and SHP1 in the late centrocyte/post-GC stage, regardless of EBV infection.

MeSH terms

  • Active Transport, Cell Nucleus
  • Cell Differentiation*
  • Cell Nucleus / metabolism*
  • Cells, Cultured
  • Enterocytes / cytology*
  • Germinal Center / cytology*
  • Humans
  • Hyaluronan Receptors / analysis
  • Hyaluronan Receptors / biosynthesis*
  • Interferon Regulatory Factors / analysis
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6 / analysis
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6 / metabolism*
  • Tissue Inhibitor of Metalloproteinase-1 / analysis
  • Tissue Inhibitor of Metalloproteinase-1 / physiology*

Substances

  • CD44 protein, human
  • Hyaluronan Receptors
  • Interferon Regulatory Factors
  • Tissue Inhibitor of Metalloproteinase-1
  • interferon regulatory factor-4
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6