Transforming growth factor-beta and nitrates in epithelial ovarian cancer.

Abstract

The role of transforming growth factor-β (TGF-β) and nitric oxide (NO) in ovarian neoplasia is still not clear. We studied the expression of TGF-β by enzyme immunoassay, and nitrates (as a stable end product of NO) in 127 ovarian tissues (36 normal, 37 benign, and 54 malignant). Ploidy status and synthetic phase fraction (SPF) were also assessed by flow cytometry. Mean ranks of TGF-β, nitrate, and SPF were significant among different groups (X2 = 12.01, P = 0.0025, X2 = 67.42, P = 0.000, X2 = 9.06, P = 0.011 respectively). Nitrate mean ranks were significant among different FIGO stages of the disease (X2 = 17.6, P = 0.000). A significant correlation was shown between TGF-â, and nitrate levels in all tissues (r = 0.24, P = 0.01), as well as in malignant tissues (r = 0.3, P = 0.026). Cutoff values were determined for both TGF-β (290 pg/mg protein), and nitrates (310 nmole/mg non protein nitrogenous substances). At these cut-offs, nitrates showed a sensitivity of 93% and 84% specificity for malignant versus normal cases, while TGF-β had 76% sensitivity, and 82.4% specificity for poor versus good outcome. Patients with epithelial ovarian cancer were followed up for a total of 40 months. Survival analysis showed that patients with TGF-β above the cut-off had worse prognosis (X2 = 12.69, P = 0.004). The present results suggest that malignant transformation of ovarian tissues is associated with increased TGF-β and NO production. NO level is related to the development and progression of epithelial ovarian cancer, while high levels of TGF-β could be of prognostic significance.