KDM1A confers invasive and metastatic attributes in lung adenocarcinoma by modulating a non-canonical Integrin ß3-KRAS signaling pathway

KRAS mutations occur in approximately 25% of non-small cell lung cancer (NSCLC). They account for the therapy resistance to EGFR inhibitors and are suggested to be difficult to target by specific drugs. Therefore, new therapies for KRAS mutant NSCLC are urgently needed. The histone H3K4 and H3K9 di/mono-demethylase KDM1A is a key epigenetic writer, aberrantly upregulated in many cancer types, including NSCLC. In order to understand the functional role of KDM1A in the progression of lung adenocarcinoma, KDM1A expression profiles were analysed in tissue microarrays (TMAs) including 182 lung adenocarcinoma. KDM1A expression correlated with high grade and metastasized tumor. To investigate the impact of KDM1A in lung adenocarcinoma development, we used the KRAS mutated A549 cell line to establish a shRNA-mediated stable KDM1A knockdown cell clone. Unexpectedly, KDM1A knockdown had only a slight effect on retardation of cell growth. However, cell invasion and self-renewal capability was significantly decreased by KDM1A inhibition. KDM1A knockdown in A549 cell resulted in a dramatic change in the transcriptome profile as determined by RNA-Seq. Interestingly, genes involved in the KRAS signature and lung epithelial marker genes were significantly affected upon KDM1A knockdown. Ingenuity pathway analysis also suggested that the alternative integrin ß3-KRAS signaling axis, which is involved in stem cell like properties, is abrogated upon KDM1A knockdown. Indeed, Integrin ß3 and its non-canonical ligand galectin-3 were strongly downregulated and their downstream NF-?B activity was decreased upon KDM1A knockdown. Finally, correlation of KDM1A to the Integrin ß3 level was validated in TMAs. Overall design: Determining the role of KDM1A in A549 cells, mRNA profiles of control and knockdown samples of A549 cells, generated by deep sequencing, in triplicate, using Illumina HiSeq 2500.

6

Lim SY, Macheleidt I, Dalvi P, Schäfer SC, Kerick M, Ozretić L, Ortiz-Cuaran S, George J, Merkelbach-Bruse S, Wolf J, Timmermann B, Thomas RK, Schweiger MR, Buettner R, Odenthal M