Effects of CTGF/Hcs24, a product of a hypertrophic chondrocyte-specific gene, on the proliferation and differentiation of chondrocytes in culture

Endocrinology. 2000 Jan;141(1):264-73. doi: 10.1210/endo.141.1.7267.


Recently, we cloned a messenger RNA (mRNA) predominantly expressed in chondrocytes from a human chondrosarcoma-derived chondrocytic cell line, HCS-2/8, by differential display PCR and found that its gene, named hcs24, was identical with that of connective tissue growth factor (CTGF). Here we investigated CTGF/Hcs24 function in the chondrocytic cell line HCS-2/8 and rabbit growth cartilage (RGC) cells. HCS-2/8 cells transfected with recombinant adenoviruses that generate CTGF/Hcs24 sense RNA (mRNA) proliferated more rapidly than HCS-2/8 cells transfected with control adenoviruses. HCS-2/8 cells transfected with recombinant adenoviruses that generate CTGF/Hcs24 sense RNA expressed more mRNA of aggrecan and type X collagen than the control cells. To elucidate the direct action of CTGF/Hcs24 on the cells, we transfected HeLa cells with CTGF/Hcs24 expression vectors, obtained stable transfectants, and purified recombinant CTGF/Hcs24 protein from conditioned medium of the transfectants. The recombinant CTGF/Hcs24 effectively promoted the proliferation of HCS-2/8 cells and RGC cells in a dose-dependent manner and also dose dependently increased proteoglycan synthesis in these cells. In addition, these stimulatory effects of CTGF/Hcs24 were neutralized by the addition of anti-CTGF antibodies. Furthermore, the recombinant CTGF/Hcs24 effectively increased alkaline phosphatase activity in RGC cells in culture. Moreover, RT-PCR analysis revealed that the recombinant CTGF/Hcs24 stimulated gene expression of aggrecan and collagen types II and X in RGC cells in culture. These results indicate that CTGF/Hcs24 directly promotes the proliferation and differentiation of chondrocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Blotting, Western
  • Cartilage / cytology
  • Cell Differentiation / drug effects
  • Cell Division / drug effects
  • Cells, Cultured
  • Chondrocytes / cytology*
  • Chondrocytes / ultrastructure
  • Collagen / biosynthesis
  • Connective Tissue Growth Factor
  • DNA, Neoplasm / biosynthesis
  • Growth Substances / genetics*
  • Growth Substances / pharmacology*
  • Humans
  • Immediate-Early Proteins*
  • Intercellular Signaling Peptides and Proteins*
  • Proteoglycans / biosynthesis
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Rabbits
  • Recombinant Proteins / pharmacology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection


  • CCN2 protein, human
  • DNA, Neoplasm
  • Growth Substances
  • Immediate-Early Proteins
  • Intercellular Signaling Peptides and Proteins
  • Proteoglycans
  • RNA, Messenger
  • Recombinant Proteins
  • Connective Tissue Growth Factor
  • Collagen