title: Integrative Genomics Implicates EGFR as a Downstream Mediator in NKX2-1 Amplified Non-Small Cell Lung Cancer.
abstract: NKX2-1, encoding a homeobox transcription factor, is amplified in approximately 15% of non-small cell lung cancers (NSCLC), where it is thought to drive cancer cell proliferation and survival. However, its mechanism of action remains largely unknown. To identify relevant downstream transcriptional targets, here we carried out a combined NKX2-1 transcriptome (NKX2-1 knockdown followed by RNAseq) and cistrome (NKX2-1 binding sites by ChIPseq) analysis in four NKX2-1-amplified human NSCLC cell lines. While NKX2-1 regulated genes differed among the four cell lines assayed, cell proliferation emerged as a common theme. Moreover, in 3 of the 4 cell lines, epidermal growth factor receptor (EGFR) was among the top NKX2-1 upregulated targets, which we confirmed at the protein level by western blot. Interestingly, EGFR knockdown led to upregulation of NKX2-1, suggesting a negative feedback loop. Consistent with this finding, combined knockdown of NKX2-1 and EGFR in NCI-H1819 lung cancer cells reduced cell proliferation (as well as MAP-kinase and PI3-kinase signaling) more than knockdown of either alone. Likewise, NKX2-1 knockdown enhanced the growth-inhibitory effect of the EGFR-inhibitor erlotinib. Taken together, our findings implicate EGFR as a downstream effector of NKX2-1 in NKX2-1 amplified NSCLC, with possible clinical implications, and provide a rich dataset for investigating additional mediators of NKX2-1 driven oncogenesis.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Nicole
authors.initials: N
authors.lastname: Clarke
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Jewison
authors.initials: J
authors.lastname: Biscocho
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Kwei
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Jean M
authors.initials: JM
authors.lastname: Davidson
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Sushmita
authors.initials: S
authors.lastname: Sridhar
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Xue
authors.initials: X
authors.lastname: Gong
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Pollack
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics*; D000069347:Erlotinib Hydrochloride / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D009687:Nuclear Proteins; D047428:Protein Kinase Inhibitors; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D000069347:Erlotinib Hydrochloride; C512478:EGFR protein, human; D066246:ErbB Receptors