Low expression of miR125a-5p predicts sensitivity to sorafenib by upregulating STAT3 and HTATIP2 in hepatocellular carcinoma

Abstract

Abstract Background Sorafenib is a standard of care for systemic therapy of hepatocellular carcinoma (HCC). Further personalized treatment with sorafenib is warranted. The current study aims to identify predictive biomarkers for the efficacy of sorafenib and investigate the underlying mechanism. Methods MiRNA array was performed in formalin-fixed paraffin-embedded tumour from patients who received adjuvant sorafenib therapy after liver resection, including patients who had tumor recurrence within one year and patients without tumor recurrence after liver resection. In situ hybridization (ISH) was performed to evaluate the expression of miR-125a-5p, and the association of miR125a-5p with overall survival (OS) and recurrence free survival (RFS) was evaluated. LM3 with miR125a-5p overexpression and SMMC7721 with miR125a-5p knockdown were constructed using lentiviruses respectively. The sensitivity to sorafenib treatment were studied by in vitro CCK8 assay and in vivo xenograft tumor model. RNA-seq, luciferase reporter assay, real-time PCR and Western blot assays were performed to elucidate the underlying mechanism. Results MiR125a-5p was among the most significantly changed microRNAs and low expression of miR125a-5p was associated with increased sensitivity to sorafenib. In situ hybridization and survival analysis found that higher miR125a-5p was associate with improved OS and RFS for HCC patients after liver resection. We overexpressed miR125a-5p in LM3 HCC cells and knockdown miR-125a-5p in SMMC7721, respectively, and confirmed that miR125a-5p overexpression caused sorafenib resistance both in vivo and in vitro, while miR125a-5p suppression led to sensitivity to sorafenib treatment. RNAseq and pathway analysis revealed that STAT3 pathway was downregulated by miR125a-5p. STAT3 was also confirmed as a target of miR125a-5p by TargetScan prediction, and both STAT3 and HTATIP2 were downregulated by miR125a-5p in in-vitro experiment. Conclusion Low expression of miR125a-5p predicted sorafenib sensitivity by upregulating STAT3 and HTATIP2.