microRNAs as tumor inhibitors, oncogenes, biomarkers for drug efficacy and outcome predictors in lung cancer (Review)

Lung cancer remains the leading cause of cancer-related death worldwide for both men and women, and non-small cell lung cancer (NSCLC) accounts for approximately 80% of all cases. Despite improvements in early diagnosis and newly developed therapies, the 5-year survival rate for NSCLC patients remains low (15%). Therapy in NSCLC has reached a plateau. Understanding genomic medicine may provide insight into the oncogenesis of lung cancer and open the door to molecular diagnosis, new biomarkers and a more accurate prognosis of lung cancer. It is well known that almost half of the genes regulated by microRNAs (miRNAs) are located in cancer-associated genomic regions. In the present study, we discuss the potential of miRNAs to function as suppressors and biomarkers for chemoresistance and prognosis of lung cancer.