Changes of Three kinds of miRNAs, MALAT1 and PI3K/AKT/mTOR signaling pathway Protein Levels in Her-2 Positive Breast Cancer in neoadjuvant chemotherapy and their relationship with prognosis- -A small sample study report

Abstract

Objective To investigate the roles of three kinds of miRNAs , Lnc MALAT1 and related proteins of PI3K/AKT/mTOR signaling pathway in neoadjuvant chemotherapy of patients with Her-2 positive breast cancer (BC) and analysed their related mechanisms. Method The frozen tumor tissue and serum samples before and after neoadjuvant chemotherapy of 14 cases patients with Her-2 positive BC who received neoadjuvant chemotherapy were collected. The relative expressions level of MiR-99a, MiR-455, MiR-143, MALAT1 and related proteins of PI3K/AKT/mTOR signaling pathway in tumor tissue and a part of serum samples were detected by qRT-PCR or western blot. Results MiR-99a level was negatively correlated with RFS and OS before and after chemotherapy. MiR-99a and MiR-455 levels after chemotherapy was negatively correlated with OS. The serum MALAT1 level was negatively correlated with RFS and OS in chemosensitivity group before and after chemotherapy. In chemotherapy resistance group, p-AKT level before chemotherapy was negatively correlated with T stage, p-mTOR level after chemotherapy was positively correlated with lymph node stage and negatively correlated with RFS and OS, PTEN level was negatively correlated with clinical TNM stage. Conclusion Serum MALAT1 and MiR-99a, MiR-455, MiR-143, p-AKT, p-mTOR and PTEN of tumor tissues in Her-2 positive BC patients can be used as markers to judge neoadjuvant chemotherapy sensitivity in Her-2 positive BC. Chemotherapy resistance is may be related to PI3K/AKT/mTOR signaling pathway.