Recombinant humanized type III collagen inhibits ovarian cancer and induces protective anti-tumor immunity by regulating autophagy through GSTP1

Ovarian cancer (OC) is one of the leading causes of death from malignancy in women and lacks safe and efficient treatment. The novel biomaterial, recombinant humanized collagen type III (rhCOLIII), has been reported to have various biological functions, but its role in OC is unclear. This study aimed to reveal the function and mechanism of action of rhCOLIII in OC. We developed an injectable recombinant human collagen (rhCOL)-derived material with a molecular weight of 45 kDa, with a stable triple helix structure, high biocompatibility, water solubility and biosafety. The anti-tumor activity of rhCOLIII was comprehensively evaluated through <i>in vitro and in vivo</i> experiments. <i>In vitro</i>, our results showed that rhCOLIII inhibited the proliferation, migration, and invasion of ovarian cancer cells (OCCs), and induced apoptosis. In addition, rhCOLIII not only inhibited autophagy of OCCs but also increased the expression of MHC-1 molecule within OCCs. To further elucidate the mechanism of rhCOLIII in OC, we conducted joint analysis of RNA-Seq and proteomics, and found that rhCOLIII exerted anti-tumor function and autophagy inhibition by downregulating Glutathione S-transferase P1 (GSTP1). Furthermore, various rescue experiments were designed to demonstrate that rhCOLIII suppressed autophagy and proliferation of OCCs by mediating GSTP1. <i>In vivo</i>, we found that rhCOLIII could inhibit tumor growth and promote CD8⁺ T cell infiltration. Our results indicate that rhCOLIII has great anti-tumor potential activity in OC, and induces protective anti-tumor immunity by regulating autophagy through GSTP1. These findings illustrate the potential therapeutic prospects of rhCOLIII for OC treatment.