The effects of 17β-estradiol on mitochondrial biogenesis and function in breast cancer cell lines are dependent on the ERα/ERβ ratio.

BACKGROUND/AIMS: 17β-estradiol (E2) is a risk factor for the development of breast cancer, and cause tumorigenesis in epithelial breast cells. Moreover, E2 has distinct effects on different tissues that are attributed to the presence of two estrogen receptor isoforms, ERα and ERβ.

METHODS: The effect of E2 on mitochondrial biogenesis and function was investigated in two breast cancer cell lines with different estrogen receptor ratios, MCF-7 (high ERα/ERβ ratio) and T47D (low ERα/ERβ ratio) cell lines treated with physiological concentrations of E2 (1 nM).

RESULTS: Mitochondria of the MCF-7 cell line showed an increase in proliferation but a decrease in functionality, while the T47D cell line, with low ERα/ERβ ratio, maintained functionality with fewer mitochondria.

CONCLUSION: Our results suggest that ERs endowment and its subtypes relation have an effect on treatment response and could contribute new ideas about mitochondria and ERs in breast cancer, as well as new indicators to the disease progression.