Inhibition of PIK3CA by miR-203a-3p reduces hypertrophic scar formation via PI3K/AKT/mTOR signaling pathway

Hypertrophic scar (HS) is a skin fibroproliferative disease currently having no truly effective therapy. PIK3CA is a catalytic subunit of PI3K able to promote collagen synthesis in benign fibrotic diseases and to regulate cell survival, proliferation, and adhesion in malignancies. To explore PIK3CA’s functions in HS formation, we performed transcriptome sequencing and experimental validation. PIK3CA were overexpressed in HS tissues, and positively correlated with fibrosis. We then screened out miR-203a-3p as the most suitable endogenous inhibitor of PIK3CA through bioinformatics. Intriguingly, miR-203a-3p suppressed the proliferation, migration, collagen synthesis, and contractility, as well as trans-differentiation of fibroblasts into myofibroblasts in vitro, improved the morphology and histology of HS in vivo. Mechanistically, miR-203a-3p attenuated fibrosis by inactivating PI3K/AKT/mTOR pathway via directly targeting PIK3CA. In conclusion, Our findings identified that PIK3CA and PI3K/AKT/mTOR pathway were actively involved in HS formation and demonstrated that miR-203a-3p might serve as a potential strategy for HS therapy through targeting PIK3CA and inactivating PI3K/AKT/mTOR pathway. To investigate the function of miR-203a-3p in the regulation of hypertrophic scar fibroblasts (HSFs) fibrosis, we established HSFs cell lines in which miR-203a-3p has been overexpressed by lentivirus.