Inhibiting Pyk2/Src expression by miR-23b-3p suppressed liver cancer stem cell function and hepatic carcinoma progression.

BACKGROUND: Liver cancer stem cells (LCSCs) are critical drivers of metastasis and chemoresistance in hepatocellular carcinoma (HCC). Proline-rich tyrosine kinase 2 (Pyk2) has been implicated in tumor progression, but its role in LCSC stemness and HCC malignancy remains unclear. This study explores the effects of Pyk2 and its regulation by miR-23b-3p on LCSC function and HCC progression. METHODS: LCSCs were enriched from HepG2 and HCCLM3 cell lines, and Pyk2 knockdown was induced through siRNA transfection, with or without miR-23b-3p inhibitor co-transfection. We assessed cell proliferation, sphere formation, migration, invasion, and chemosensitivity. Stemness markers (Nanog, Oct4, Sox2, KLF4, and Bmi1) and Pyk2/Src signaling were analyzed via RT-qPCR, Western blotting, and immunohistochemistry. In vivo, tumor growth and Pyk2/Src expressions were evaluated in a BALB/c mouse xenograft model. RESULTS: Pyk2 expression was significantly elevated in the identified LCSCs compared to the parental HCCs. Pyk2 knockdown significantly suppressed the LCSCs proliferation, sphere formation, migration, invasion, and enhanced chemosensitivity. The expression of stemness markers and miR-23b-3p was significantly inhibited in HCCLM3-LCSC(siPyk2) cells. miR-23b-3p inhibition restored Pyk2 level and Src phosphorylation, reversing the suppressive effects of Pyk2 knockdown. In BALB/c mice, tumor volume, weight, and Pyk2/Src expressions were significantly elevated in HCCLM3-LCSC and HCCLM3-LCSC(siPyk2)+miR-23b-3p inhibitor groups comparing to HCCLM3/HCCLM3-LCSC(siPyk2) groups, whereas were even heightened in the HCCLM3-LCSC + miR-23b-3p inhibitor group. CONCLUSIONS: Inhibiting Pyk2/Src expression by miR-23b-3p suppressed LCSCs function and aggravated HCC progression. TRIAL REGISTRATION: Not applicable.