Expression of pituitary tumor-transforming gene in endometrial cancer as a prognostic marker

Abstract

The pituitary tumor-transforming gene (PTTG) is a novel oncogene expressed abundantly in most tumors, regulates basic fibroblast growth factor secretion, and induces angiogenesis. The objective of this study is to compare the expression rate of PTTG in endometrial cells, to correlate the level of expression of PTTG with the clinicopathologic parameters and overall survival, and to evaluate the possible use of PTTG as a prognostic marker of endometrial cancer. Forty patients diagnosed with endometrial cancer, 20 patients with endometrial hyperplasia, and 20 patients with normal endometrial tissues were included in the study. Immunohistochemical analyses on paraffin-embedded blocks were performed using a polyclonal anti-PTTG antibody. The decrease in expression of cytoplasmic and nuclear PTTG seen for endometrial cancer cells was statistically significant (P < 0.05). Cytoplasmic PTTG expression correlated with expression of progesterone receptor (P = 0.009) and FGF-2 (P = 0.007) but not with other parameters such as the expression of estrogen receptor, tumor grade, and surgical stage. Nuclear PTTG expression did not correlate with any parameters. The mean survival of patients with positive and negative cytoplasmic PTTG expression was 40.8 and 48.6 months (P = 0.78). In nuclear PTTG expression, the survival was 20.0 and 51.8 months, respectively (P = 0.04). Cytoplasmic PTTG expression was not associated with survival. Patients with nuclear PTTG overexpression showed a significant decrease in survival. The use of PTTG as a prognostic marker for endometrial cancer needs further investigation.