Connective tissue growth factor (CTGF) is a member of a family of immediate early gene products that may play an important role during tissue regeneration,
wound repair and skin
fibrosis. In this study, CTGF gene expression in mesenchymal
tumors was investigated by in situ hybridization and
CD34 antigen expression was studied by means of immunohistochemical staining. CTGF
mRNA was expressed in fibroblasts of all nine
dermatofibromas examined, but five of seven
dermatofibrosarcoma protuberans (DFSP) or two cases of
malignant fibrous histiocytoma were negative for its expression. In contrast,
CD34 antigen was expressed only in DFSP. In vascular
tumors, CTGF
mRNA was expressed in
pyogenic granuloma but not in
angiosarcoma. In addition, the endothelial cells in
angiolipoma and
angioleiomyoma, but not in venous lake, expressed CTGF
mRNA. These vascular lesions were all positive for CD34 expression.
Tumors of other origins were negative for CTGF
mRNA. Our findings indicated that benign fibroblasts and/or vascular endothelial cells have the capability to express CTGF
mRNA when activated, but these cells lose this ability when they achieve malignant potency. Thus, examination of CTGF gene expression may be useful for differentiating between benign and malignant mesenchymal
tumors, or to determine the origin of the
tumors in connective tissue.