Clinical significance of SPRY4-IT1 in efficacy and survival prediction in breast cancer patients undergoing neoadjuvant chemotherapy.

Breast cancer is the most frequent malignancy and the leading cause of cancer death among females. Long noncoding RNAs (lncRNAs) are under investigation as novel prognostic biomarkers in cancer. The aim of the study was to investigate the expression, clinical implications and prognostic significance of lncRNA SPRY4-IT1, and to identify the predictive value of SPRY4-IT1 on the outcome of chemotherapy in breast cancer patients undergoing neoadjuvant chemotherapy (NACT). Bioinformatics indicated SPRY4-IT1 was related to chemo-resistance in breast cancer. SPRY4-IT1 expression was assessed by qRT-PCR in breast cancer tissues and matched normal breast tissues (n=26 pairs). SPRY4-IT1 expression was also detected by In situ hybridization (ISH) in 60 paraffin slices with complete clinical datum. In this study, SPRY4-IT1 was significantly more expressed in cancer tissues than in normal tissues (P<0.05). Increased SPRY4-IT1 expression was significantly corre¬lated with increased rates of lymph node metastasis (P=0.002) and recurrence (P=0.017). Both were independent factors of SPRY4-IT1 expression (P<0.05). High-SPRY4-IT1 patients had significantly lower overall survival and disease-free survival. High SPRY4-IT1 expression indicated poor clinical response in the whole group, luminal A subgroup and luminal B subgroup (P<0.05) and pathological complete response in the whole group. Overexpression of SPRY4-IT1 promoted chemo-resistance of MCF-7 and MDA-MB-231 cells to epirubicin. SPRY4-IT1 has the potential to be a biomarker to predict NACT efficacy and prognosis in breast cancer patients.