MCP-enhanced SOD3 activity inhibits gastric cancer and potentiate chemotherapy via modulating EGFR signaling.

[AIMS] This study aims to investigate the role of SOD3 in gastric cancer (GC) progression and its impact on chemotherapy efficacy and toxicity. It further seeks to evaluate the therapeutic potential of MCP in enhancing SOD3 activity to improve treatment outcomes and reduce chemotherapy-induced peripheral neurotoxicity (CIPN).

[MATERIALS AND METHODS] We used overexpression plasmids and small interfering RNAs (siRNAs) to modulate the expression of SOD3 and Desmocollin2 (DSC2) in gastric cancer cells. Molecular biology experiments were performed to analyze pathway-related protein expression and molecular interactions. In vitro and in vivo experiments were conducted to evaluate the effects of modified citrus pectin (MCP) and oxaliplatin (OXA), individually and in combination, on gastric cancer progression and CIPN.

[KEY FINDINGS] SOD3 inhibited the proliferation, migration, and invasion of GC cells via SOD3/EGFR/PKP3/DSC2 axis. MCP selectively increased SOD3 levels and enhanced its anti-tumor effects. Combined treatment with MCP and OXA synergistically inhibited GC progression in vitro and in vivo, while MCP alleviated CIPN, enabling OXA dose reduction without compromising efficacy.

[SIGNIFICANCE] The findings revealed that SOD3 played a critical tumor-suppressive role in gastric cancer by modulating the SOD3/EGFR/PKP3/DSC2 axis. MCP, a natural compound that selectively boosted SOD3 levels, enhanced chemotherapy efficacy while reducing peripheral neurotoxicity, providing a promising strategy to improve gastric cancer treatment and mitigate chemotherapy-related side effects.