[microRNA expression profiling of side population cells in human lung cancer and preliminary analysis].

BACKGROUND AND OBJECTIVE: Recent studies indicate that the side population (SP) which is an enriched source of cancer stem cells (CSCs) is the root cause of tumor growth and development. SP appears to be highly resistant to chemo- and radio-therapy which becomes an important factor in tumor recurrence and metastasis. The aim of this study is to determine the difference of microRNA expression profiles between SP cells and non-SP cells so as to lay necessary basis for research on the function of miRNA in lung cancer stem cells. METHODS: SP and non-SP cells were isolated using flow cytometry and Hoechst 33342 dye efflux assay from human lung adenocarcinoma A549 cell. The total RNA was extracted. The microarray detection system was employed to analyze whether there was difference in miRNA expression profile between SP and non-SP cells. RESULTS: A total of 85 differentially expressed miRNA were found, including 32 over-expression and 53 low-expression miRNA in SP. CONCLUSIONS: miRNA may play important roles in tumorigenesis of lung cancer stem cell. The study of miRNA contributes to elucidate the molecular mechanism of lung cancer stem cell.