Identification of microRNAs involved in pathways characterizing the expression subtypes of NSCLC

The aim of this project was to identify microRNAs associated with the expression subtypes in patients diagnosed with non-small cell lung cancer. Based on mRNA expression data the samples were assign to a gene expression subtype based on 506 gene centroid classifier. The patients enrolled in this study underwent curatively intended surgical resection. Subtype-specific microRNA expression was correlated to gene set enrichment scores in order to identify associated pathways that the microRNAs may be regulating, characterizing the expression subtypes. In order to assess if the subtype-specific microRNA signal originate from the lung cancer cells or from infiltrating immune cells, we compared our subtype-specific microRNAs with the results from a study investigating human cell-specific microRNA expression. In this project the authors sequenced microRNAs from 46 primary cell types, 42 cancer cell lines and tissues (McCall MN, Kim MS, Adil M, Patil AH, Lu Y, Mitchell CJ, Leal-Rojas P, Xu J, Kumar M, Dawson VL et al: Toward the human cellular microRNAome. Genome Res 2017, 27(10):1769-1781). The results were further validated in independent NSCLC cohorts (LUAD and LUSC) from The Cancer Genome Atlas (TCGA). In this study we identified subtype specific microRNAs associated with essential processes characterizing the expression subtypes of ADs and SCCs.