Increasing evidence demonstrates that miRNAs are in-volved in the dysregulation of tumor initiating cells (TICs) in various tumors. Due to a lack of definitive markers, cell sorting is not an ideal separation method for lung adeno-carcinoma initiating cells. In this study, we combined pa-clitaxel with serum-free medium cultivation (inverse-induc-tion) to enrich TICs from A549 cells, marked by CD133/ CD326, defined features of stemness. We next investigated aberrant microRNAs in this subpopulation compared to normal cells with miRNA microarray and found that 50 miRNAs exhibited a greater than 2-fold change in expres-sion. As further validation, 10 miRNAs were chosen to perform quantitative RT-PCR on the A549 cell line and primary samples. The results suggest that aberrant ex-pression of miRNAs such as miR-29ab, miR-183, miR-17-5p and miR-127-3P may play an important role in regulat-ing the bio-behavior of TICs.

Keywords: A549, microarray, microRNA, paclitaxel, tumor initiating cells