Overexpression of Hepatoma-Derived Growth Factor in Melanocytes Does Not Lead to Oncogenic Transformation

The study investigated whether overexpression of hepatoma-derived growth factor (HDGF) in melanocytes could lead to oncogenic transformation. Transgenic mice overexpressing HDGF were bred with mice carrying a defective Ink4a tumor suppressor gene and exposed to UV light. Despite overexpression of HDGF in hair follicle melanocytes, no melanomas or premelanocytic alterations were observed. Primary melanocytes from transgenic animals failed to differentiate in vitro, unlike those from wild type and HDGF-deficient animals. The findings indicated that HDGF did not have a transforming capacity in tumor development but might play a role in cell differentiation and tumor progression after secondary upregulation, fitting into the concept of non-oncogene addiction of tumor tissue.