Interleukin-6 regulates expression of estrogen receptors in human colorectal cancer and acute T-cell leukemia cells

Interleukin-6 (IL-6) is a pleiotropic cytokine involved in inflammation, immune regulation, and tumor progression. Estrogen receptors (ERs), particularly ERα and ER, play distinct roles in modulating immune responses and cancer development, yet their regulation by IL-6 in different cancer types remains incompletely understood. In this study, we investigated the effects of IL-6 on expression of ERα and ERβ in human colorectal cancer cells (HCT116) and acute T-cell leukemia cells (Jurkat). The cells were treated with recombinant human IL-6 (at a dosage of 100 ng/ml) for up to 24 hours, and changes in ER expression were assessed using Western blot analysis. We found that IL-6 treatment did not significantly alter ERα or ERβ levels in HCT116 cells, though a non-significant upward trend in ERβ expression was observed. In contrast, Jurkat cells exhibited a statistically significant increase in ERβ expression at 8 and 24 hours after IL-6 stimulation, while ERα expression remained unchanged. These findings suggest a cell-type-specific regulatory role of IL-6 in modulating estrogen receptor expression. The selective upregulation of ERβ in Jurkat cells implies a potential IL-6-ERβ signaling axis in T-cell leukemia, which may contribute to inflammation-driven leukemogenesis and warrants further mechanistic investigation.