Adiponectin Can Affect ER Signaling in Obese Breast Cancer Patients

Abstract

Background: While the various antitumororal activities of adiponectin as an adipocyte-derived hormone well studied, it is speculated that there is a crosstalk between adiponectin and esterogen receptor (ER) signaling. To test this hypothesis we evaluate the possible correlation between serum level of adiponectin with two estrogen receptors (ERα and ERβ) gene expression in breast cancer patients. Methods: In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI < 25 kg/m 2 and 34 obese, BMI ≥ 25 kg/m 2 ).The mean age of Participants was 44.53 yr ± 1.79 yr (21 yr - 70 yr) .Serum level of adiponectin determined by ELISA. Following quantitative expression of estrogen receptors mRNA in tumor tissues was evaluated by Real-time PCR. Results: We find a significant reverse correlation between serum level of Adiponectin and ERα mRNA (r = –0.229, n = 64, p = 0.035) but no correlation was between adiponectin and ERβ in samples (p = 0.228). The lower adiponectin multiplied the odds of having higher ERα mRNA level by a factor of OR = 4.33, 1.28 - 14.6, 95% confidence interval (CI) as compared with those that displayed a moderate or higher serum level of adiponectin (>7.02 ng/ml). The same odds for next estrogen receptor, ERβ, was not greater than unity (OR = 0.31, 0.06 - 1.56, 95% CI). Conclusion: According to the obtained results, it is speculated that as adiponectin can affect ERs gene expression, so affecting the steroid receptor signaling can be proposed as a new underling mechanism of action for this adipokine in breast cancer pathogenesis especially in obese ones.