GRB2 Promotes Malignant Behaviors of Breast Cancer by Modulating the Global Expression and Alternative Splicing Profiles in SK‐BR‐3 Cells Through Binding mRNA

ABSTRACT Purpose The flexible protein GRB2 interacts with HER1–4 on the cell surface and regulates the development of tumor cells; meanwhile, it is also an RBP that plays an important role in post‐transcriptional regulation in eukaryotes, which affects every stage of mRNA synthesis, modification, splicing, and stabilization. Although some studies have found a connection between GRB2 and HER2‐overexpression breast cancer, highlighting the potential of GRB2 as a novel biomarker that stimulates tumor growth, limited data were available to elaborate on their interaction mechanisms. Methods In this research, we found 396 different gene expressions between the Grb2‐knockdown group and the SK‐BR‐3 group by the RNA sequencing approach. After GRB2 was knocked down, 956 alternative splicing events occurred. Results The fRIP‐seq results showed that GRB2‐binding reads were significantly enriched in the intron region, indicating that UUAGC and UUGGUUGG might be the binding motifs. An integration analysis of DEGs with the peak genes of fRIP‐seq revealed that 63 genes possess GRB2 binding sites on their mRNAs or antisense RNAs. By integration analysis of AS events with the peak genes of fRIP‐seq, 66 genes related to AS events were found. Conclusions Above, these AS events may be regulated by GRB2 to promote the progression of HER2‐overexpression breast cancer.