Potential signaling pathways and gene signatures associated with brain metastases in NSCLC patients

RNA-Seq analyses of various cancers have identified thousands of target genes that help guide clinical treatment. By using RNA-Seq analysis, we examined primary lung tumors from NSCLC patients with and without BM to identify differentially-expressed genes and potential signaling pathways in two groups. A total of 6 patients with histopathologically confirmed NSCLC (against AJCC criteria) were enrolled in the RNA-Seq study, 3 patients with BM and other 3 without BM. All the cancer tissues used in this study were taken from surgical specimens and biopsies, and preserved immediately in liquid nitrogen after surgery. Totally, 566 differentially-expressed genes between BM+ and BM- samples were identified by DESeq2 with log2Fold Change being more than 2 and P value of statistical test less than 0.05, 326 genes were significantly down-regulated and 240 genes were up-regulated in BM+ group. RNA isolation and RNA sequencing were performed in 6 NSCLC patients, 3 patients with BM and other 3 without BM. All libraries were sequenced on the Illumina Hiseq 2500 Sequencer.