The Possible Impact of Obesity on Androgen, Progesterone and Estrogen Receptors (ERα and ERβ) Gene Expression in Breast Cancer Patients

Abstract

BackgroundObesity has been associated with increased mortality from hormone dependant cancers such as breast cancer which is the most prevalent cancer in women. The link between obesity and breast cancer can be attributed to excess estrogen produced through aromatization in adipose tissue. The role of steroid hormone receptors in breast cancer development is well studied but how obesity can affect the expression pattern of steroid hormones in patients with different grades of breast cancer was the aim of this study.MethodsIn this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI < 25 kg/m2 and 34 obese, BMI ≥ 25 kg/m2). The mean age of participants was 44.53 ± 1.79 yr (21–70 yr). The serum level of estrogen, progesterone and androgen determined by ELISA. Following quantitative expression of steroid hormone receptors mRNA in tumor tissues evaluated by Real-time PCR. Patients with previous history of radiotherapy or chemotherapy were excluded. SPSS 16 was used for data analysis and P < 0.05 considered statistically significant.ResultsThe difference in ERα, ERβ and PR mRNA level between normal and obese patients was significant (P < 0.001). In addition, the expression of AR mRNA was found to be higher than other steroid receptors. There was no significant relation between ERβ gene expression in two groups (P = 0.68). We observed a significant relationship between ERα and AR mRNA with tumor stage and tumor grade, respectively (P = 0.023, P = 0.015).ConclusionAccording to the obtained results, it is speculated that obesity could paly a significant role in estrogen receptors gene expression and also could affect progression and proliferation of breast cancer cells.

Effects of Obesity on Presentation of Breast Cancer, Lymph Node Metastasis and Patient Survival: A Retrospective Review

“…Our results were in consistent with previous studies that showed expression of PR is more frequent in obese women (Esfahlan et al, 2011). Ove Maehle et al revealed that obese women have higher chance of having PR positive and ER positive tumor.…”

The expression of the estrogen receptor in obese patients with high breast density (HBD)

“…In the same sense, Wedrén et al [21], analyzed the relationship of polymorphic variants in the ERa gene, BC and risk factors, and concluded that there was positive relationship of these polymorphisms with BC only in women with a high BMI (Xbal ¼ 1.41; PvuII ¼ 1.48). Our data confirmed the data of others researches as the article published by Esfahlan et al [22], in which they concluded that the expression of ERa was significantly higher in obese patients, factor that influenced the progression and proliferation of breast cancer cells (p ¼ 0.001).The BC is a heterogeneous disease and risk factors may be differentially associated with the development of distinct subtypes of tumors. In our data, we observe that the PvuII polymorphism was associated with lower weight women.…”

Quantification of Steroid Receptors Gene Expression in Breast Cancer Patients: Possible Correlation with Serum Level of Adipocytokines

“…Approximately 100 mg of tissue for RNA extraction by means of RNAX reagents previously described [25] .The quality of RNA samples was ensured by electrophoresis in an agarose gel followed by ethidium bromide staining, where the 18 S and 28 S RNA bands could be visualized under UV light. Quantification of RNA was performed in duplicate by spectrophometry at 260 nm.…”

“…The qRT-PCR assay of steroid receptors in details have been described in our previous work [25]. Primer sequences for qRT-PCR summarized in Table 1.…”