Overexpression of LMOD1 induces oxidative stress and enhances cell apoptosis of melanoma through the RIG-I like receptor pathway.

Background: Oxidative stress is crucial in the development of cutaneous melanoma, but its role in melanoma is controversial. We aimed to identify melanoma-associated targets and understand the underlying mechanism.

Methods: Differential expressed genes (DEGs) were discovered between control and melanoma samples, and a protein-protein interaction (PPI) network was constructed to find key genes. The prediction accuracy of LMOD1 was assessed by receiver operating characteristic (ROC) curves, and pan-cancer analysis was also performed for LMOD1 expression and immune characteristics. The downstream pathway of LMOD1 was found via KEGG analysis. The effects of LMOD1 on oxidative stress, apoptosis, CD4 + T cells and the downstream pathway were evaluated in melanoma cells and mice.

Results: We identified ACTG2, CNN1, LMOD1, MYH11, MYL9, MYLK, TAGLN, TPM1 and TPM2 as melanoma-related DEGs, which could separate control and melanoma samples. The area under curve (AUC) of LMOD1 was > 0.89, indicating high prediction accuracy. LMOD1 expression was decreased in melanoma, and LMOD1 notably correlated with B cells, CD4 T cells, neutrophils, macrophages and dendritic cells (DCs). Overexpression of LMOD1 promoted apoptosis, enhanced migration and invasion, and activated oxidative stress in melanoma cells. LMOD1 promoted apoptosis via activating oxidative stress. The RIG-I-like receptor signaling (RLR) was a downstream pathway of LMOD1. Overexpression of LMOD1 activated oxidative stress, increased apoptosis and CD4 + T cells, and elevated RIG-I and MDA5, while Cyclo (Phe-Pro) (cFP) reversed the results.

Conclusion: LMOD1 triggers oxidative stress-mediated apoptosis in melanoma via activating the RLR pathway, which provides promising targets and regulatory pathway for melanoma.