High glucose promotes prostate cancer cells apoptosis via Nrf2/ARE signaling pathway.

Abstract

To explore the influences of high glucose on the proliferation and apoptosis of prostate cancer cells and analyze its possible mechanism of action. Human prostate cancer cell line LNCaP was divided into control group, mannitol group, and high glucose group. Then, the proliferation in each group was detected via methyl-thiazolyl-tetrazolium (MTT) assay. Hoechst staining assay was performed to determine the apoptosis level in each group. Western blotting was employed to measure the expression levels of apoptosis-related proteins and nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and γ-glutamylcysteine synthetase (γ-GCS) proteins. The cellular reactive oxygen species (ROS) level was measured through 2,7-dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. Enzyme-linked immunosorbent assay (ELISA) was carried out to detect the content of lactate dehydrogenase (LDH) and inflammatory factors. High glucose significantly promoted the proliferation of prostate cancer cells LNCaP (p<0.01) and increased the apoptosis level of cells (p<0.01). In high glucose group, the expression level of Caspase-3 protein was overtly increased (p<0.01), while that of B-cell lymphoma-2 (Bcl-2)/Bcl-2 associated X protein (Bax) was significantly decreased (p<0.01). High glucose group had clearly increased the content of ROS (p<0.01), LDH (p<0.01), and interleukin-6 (IL-6) (p<0.01), but decreased the content of IL-10 (p<0.01). High glucose notably lowered the protein expression levels of Nrf2, HO-1, and γ-GCS in the cells (p<0.01). High glucose represses the activation of the Nrf2/anti-oxidation response element (ARE) signaling pathway in prostate cancer cells and increases the content of ROS, IL-6, and the expression of apoptotic proteins in the cells, thus promoting the apoptosis of prostate cancer cells.