Detailed molecular analysis revealed that known tumor promoters such as pituitary tumor-transforming gene were activated and tumor suppressors such as peroxisome proliferator-activated receptor gamma and p53 were suppressed during carcinogenesis.
The product of the pituitary tumor-transforming gene (PTTG) inhibits chromatid separation, which is considered to promote chromosome instability, especially in the absence of the p53 gene product, and also induces basic fibroblast growth factor (bFGF) production.