Protective Effects of Relaxin 2 (RLXH2) against Hypoxia-Induced Oxidative Damage and Cell Death via Activation of The Nrf2/HO-1 Signalling Pathway in Gastric Cancer Cells

Objective: This study aims to investigate the potential role of relaxin, a peptide hormone, in preventing cellulardeterioration and death in gastric carcinoma cells under hypoxic conditions. It explores the effects of recombinantrelaxin 2 (RLXH2) on growth, cell differentiation, invasive potential, and oxidative damage in these cells.Materials and Methods: In this experimental study, the NCI-N87 cell line was cultured under normal conditions andthen subjected to hypoxia using cobalt chloride (CoCl2). The cells were treated with RLXH2, and various assayswere performed to assess cellular deterioration, death, and oxidative stress. Western blot and quantitative real timepolymerase chain reaction (qRT-PCR) were used to measure the expression levels of nuclear factor erythroid 2-relatedfactor 2 (Nrf2) and HO-1, and the translocation of Nrf2 to the nucleus was confirmed through Western blot analysis.Results: This study demonstrates, for the first time, that RLXH2 significantly reduces the formation of reactive oxygenspecies (ROS) and the release of lactate dehydrogenase (LDH) in gastric cancer cells under hypoxic conditions.RLXH2 also enhances the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase(CAT), leading to a decrease in hypoxia-induced oxidative damage. RLXH2 promotes the translocation of Nrf2 to thenucleus, resulting in HO-1 expression.Conclusion: Our findings suggest that RLXH2 plays a significant protective role against hypoxia-induced oxidativedamage in gastric carcinoma cells through the Nrf2/HO-1 signalling pathway. This research contributes to a betterunderstanding of the potential therapeutic applications of RLXH2 in gastric cancer treatment.