Serum miR-27a is a biomarker for the prognosis of non-small cell lung cancer patients receiving chemotherapy

BACKGROUND: Lung cancer has a high incidence and a 5-year survival rate of less than 15%. Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases. Chemotherapy and immunotherapy are the most frequently used alternative treatments for patients with advanced-stage NSCLC in whom surgery failed. Previous studies have suggested that miR-27a is involved in cancer development and progression. The purpose of this study was to investigate the clinical value of miR-27a in the prognosis of NSCLC patients after chemotherapy. METHODS: Flow cytometry was used to detect the apoptosis rate of SPC-A1 cells treated with optical cisplatin at different times. Simultaneously, the expression of miR-27a in supernatants and cells was detected. Fifty-two newly diagnosed NSCLC patients were recruited. All patients received gemcitabine and cisplatin as first-line chemotherapy and docetaxel as second-line chemotherapy. At the end of every chemotherapy cycle, a therapeutic evaluation was performed according to the RECIST criteria. The expression of serum miR-27a was detected in each cycle. RESULTS: After treatment with 2.5 µg/mL cisplatin, the apoptosis rates of SPC-A1 cells were significantly greater than those of the paired untreated control groups at 12, 24, 48 and 72 h. The expression of miR-27a in supernatants and cells was also consistent with the apoptosis rate and changed a time-dependent manner. The chi-square test showed that an increase in miR-27a after chemotherapy was more common in patients who achieved partial response (PR) than in those who achieved no response (NR) (61.5% vs. 30.8%, P=0.026). Kaplan-Meier survival analysis indicated that patients with decreased miR-27a levels had poorer outcomes than those with increased miR-27a levels (P<0.05). Furthermore, dynamic changes in serum miR-27a with a gradual increasing trend during chemotherapy predicted a good prognosis. CONCLUSIONS: Collectively, our results suggest that miR-27a is involved in the apoptosis of lung cancer cells and that serum miR-27a levels are related to the prognosis of NSCLC patients. The expression levels of miR-27a in the serum may be an independent predictor for the prognosis of NSCLC.