Differentially expressed miRNAs in lung spheroid-derived cancer stem cells

Cancer stem cells (CSCs) are believed to play an important role in cancer progression, metastasis, and the development of drug resistance. MicroRNAs (miRNAs) are involved in several processes of CSCs and are being explored as potential therapeutic targets for this population and tumor progression. Some miRNAs have been identified as dysregulated in lung cancer. However, no miRNAs have been linked to the development and maintenance of the CSC population. Therefore, to identify miRNAs associated with the CSC phenotype in lung cancer, we used the NCI-H1975 cell line, which was cultured in an ultra low attachment 24 well plate with DMEM/F12 medium, free of fetal bovine serum (FBS), supplemented with 2 mM glutamine, 20 ng per mL Epidermal Growth Factor (EGF), 10 ng per mL b Fibroblast Growth Factor (bFGF), 1X Insulin-Transferrin-Selenium (ITS), and 1X B27. These components were used to stimulate the generation of CSCs. The medium was replaced every 3 or 4 days for one month until spheroid formation occurred. Subsequently, RNA was isolated from both CSCs and adherent cells , and small RNA sequencing by Illumina was performed to identify differentially expressed miRNAs involved in CSC characteristics and maintenance. NCI-H1975 CSC = H1975 CSC NCI-H1975 adherent cells= H1975 Control