Project description:Gene function in cancer is often cell type-specific. The epithelial cell-specific transcription factor ELF3 is a documented tumour suppressor in many epithelial tumours yet displays oncogenic properties in others. Here, we show that ELF3 is an oncogene in the adenocarcinoma subtype of lung cancer (LUAD), providing genetic, functional, and clinical evidence of subtype specificity. We discover a region of focal amplification at chromosome 1q32.1 encompassing the ELF3 locus in LUAD which is absent in the squamous subtype. Gene dosage and promoter hypomethylation affect the locus in up to 80% of LUAD analysed. ELF3 expression was required for tumour growth and a pan-cancer expression network analysis supports its subtype and tissue specificity. We further show that ELF3 displays strong prognostic value in LUAD but not LUSC. We conclude that, contrary to many other tumours of epithelial origin, ELF3 is an oncogene and putative therapeutic target in LUAD.
Project description:Gene function in cancer is often cell type-specific. The epithelial cell-specific transcription factor ELF3 is a documented tumour suppressor in many epithelial tumours yet displays oncogenic properties in others. Here, we show that ELF3 is an oncogene in the adenocarcinoma subtype of lung cancer (LUAD), providing genetic, functional, and clinical evidence of subtype specificity. We discover a region of focal amplification at chromosome 1q32.1 encompassing the ELF3 locus in LUAD which is absent in the squamous subtype. Gene dosage and promoter hypomethylation affect the locus in up to 80% of LUAD analysed. ELF3 expression was required for tumour growth and a pan-cancer expression network analysis supports its subtype and tissue specificity. We further show that ELF3 displays strong prognostic value in LUAD but not LUSC. We conclude that, contrary to many other tumours of epithelial origin, ELF3 is an oncogene and putative therapeutic target in LUAD.
Project description:Gene function in cancer is often cell type-specific. The epithelial cell-specific transcription factor ELF3 is a documented tumour suppressor in many epithelial tumours yet displays oncogenic properties in others. Here, we show that ELF3 is an oncogene in the adenocarcinoma subtype of lung cancer (LUAD), providing genetic, functional, and clinical evidence of subtype specificity. We discover a region of focal amplification at chromosome 1q32.1 encompassing the ELF3 locus in LUAD which is absent in the squamous subtype. Gene dosage and promoter hypomethylation affect the locus in up to 80% of LUAD analysed. ELF3 expression was required for tumour growth and a pan-cancer expression network analysis supports its subtype and tissue specificity. We further show that ELF3 displays strong prognostic value in LUAD but not LUSC. We conclude that, contrary to many other tumours of epithelial origin, ELF3 is an oncogene and putative therapeutic target in LUAD. A subset of this data has been previously published (https://edrn.jpl.nasa.gov/ecas/data/dataset/urn:edrn:COPY_NUMBER_LEV1) PMID: 22412972
Project description:Lung cancer is a leading cause of cancer death, where the amplification of oncogenes contributes to tumorigenesis. Genomic profiling of 128 lung cancer cell lines and tumors revealed frequent focal DNA amplification at cytoband 14q13.3, a locus not amplified in other tumor types. The smallest region of recurrent amplification spanned the homeobox transcription factor TITF1 (also known as NKX2-1), previously linked to normal lung development and function. When amplified, TITF1 exhibited increased expression at both the RNA and protein level. siRNA-mediated knockdown of TITF1 in lung cancer cell lines with amplification led to reduced cell proliferation, manifested by both decreased cell-cycle progression and increased apoptosis. Our findings indicate that TITF1 amplification and overexpression contribute to lung cancer cell proliferation rates and survival, and implicate TITF1 as a lineage-specific oncogene in lung cancer. This SuperSeries is composed of the following subset Series: GSE9994: Genomic profiling identifies TITF1 as a lineage-specific oncogene amplified in lung cancer: Expression Arrays GSE10025: Genomic profiling identifies TITF1 as a lineage-specific oncogene amplified in lung cancer: aCGH Arrays Keywords: SuperSeries Refer to individual Series
Project description:Cell migration driven by actomyosin filament assembly is a critical step in tumour invasion and metastasis. Herein, we report identification of myosin binding protein H (MYBPH) as a transcriptional target of NKX2-1 (also known as TTF-1 and TITF1), a lineage-survival oncogene in lung adenocarcinoma. MYBPH inhibits assembly competence-conferring phosphorylation of the myosin regulatory light chain (RLC) as well as activating phosphorylation of LIM domain kinase (LIMK). These are unexpectedly implemented through direct physical interaction of MYBPH with Rho kinase 1 (ROCK1) rather than with RLC. In addition, MYBPH is shown to directly bind with non-muscle myosin heavy chain IIA (NMHC IIA), resulting in inhibition of NMHC IIA assembly. Thus, MYBPH plays multi-facetted roles in negative regulation of actomyosin organization, which in turn reduces cell motility, invasion, and metastasis. Finally, we also show that MYBPH is epigenetically inactivated by promoter DNA methylation in a fraction of lung adenocarcinomas abundantly expressing NKX2-1, which appears to be in accordance with its deleterious function for lung adenocarcinoma invasion and metastasis, as well as with the paradoxical association of NKX2-1 expression with favourable prognosis in lung adenocarcinoma patients. Dye-swap experiment, vector control vs. transiently transfectanted with TTF-1 in HPL1D, immortalized human peripheral lung epithelial cell line.
Project description:Despite the high prevalence and poor outcome of patients with metastatic lung cancer, the mechanisms of tumour progression and metastasis remain largely uncharacterized. We modelled human lung adenocarcinoma, which frequently harbours activating point mutations in KRAS1 and inactivation of the p53-pathway2, using conditional alleles in mice3-5. Lentiviral-mediated somatic activation of oncogenic Kras and deletion of p53 in the lung epithelial cells of KrasLSL-G12D/+;p53flox/flox mice initiates lung adenocarcinoma development4. Although tumours are initiated synchronously by defined genetic alterations, only a subset become malignant, suggesting that disease progression requires additional alterations. Identification of the lentiviral integration sites allowed us to distinguish metastatic from non-metastatic tumours and determine the gene expression alterations that distinguish these tumour types. Cross-species analysis identified the NK-2 related homeobox transcription factor Nkx2-1 (Ttf-1/Titf1) as a candidate suppressor of malignant progression. In this mouse model, Nkx2-1-negativity is pathognomonic of high-grade poorly differentiated tumours. Gain- and loss-of-function experiments in cells derived from metastatic and non-metastatic tumours demonstrated that Nkx2-1 controls tumour differentiation and limits metastatic potential in vivo. Interrogation of Nkx2-1 regulated genes, analysis of tumours at defined developmental stages, and functional complementation experiments indicate that Nkx2-1 constrains tumours in part by repressing the embryonically-restricted chromatin regulator Hmga2. While focal amplification of NKX2-1 in a fraction of human lung adenocarcinomas has focused attention on its oncogenic function6-9, our data specifically link Nkx2-1 downregulation to loss of differentiation, enhanced tumour seeding ability, and increased metastatic proclivity. Thus, the oncogenic and suppressive functions of Nkx2-1 in the same tumour type substantiate its role as a dual function lineage factor. 23 cell lines derived from primary tumor or metastasis. 6 samples analyzed to determine the effect of Nkx2-1 knockdown on gene expression
Project description:Adenocarcinoma is the most common histologic subtype of lung cancer, which is the leading cause of cancer death. We and others previously identified TTF-1, a lineage-specific transcription factor required for branching morphogenesis and physiological lung functions, as a lineage-survival oncogene in lung adenocarcinoma. However, how TTF-1 mediates survival signals remains elusive. Here we show that TTF-1 induces receptor tyrosine kinase-like orphan receptor 1 (ROR1), which in turn mediates TTF-1 survival signaling in lung adenocarcinoma. Inhibition of ROR1 impaired prosurvival signaling through the PI3K-AKT pathway and induced nuclear accumulation of FOXO1. These were found to be imposed, at least in part, through PTEN inactivation via c-Src, while ROR1 was shown to physically interact with and phosphorylate c-Src. ROR1 inhibition also elicited marked p38 activation, provoking ill-balance between prosurvival and proapoptotic signaling, and consequential “oncogenic shock.” In addition, we found that ROR1 is crucially involved in EGFR- and MET-mediated prosurvival signaling. ROR1 knockdown effectively induced apoptosis in lung adenocarcinoma cell lines with acquired EGFR TKI resistance conferred by a secondary T790M EGFR mutation, or HGF-elicited MET signaling and resultant switching of the addicted receptor tyrosine kinases (RTKs). Taken together, our findings indicate that ROR1 RTK is a very promising molecular target for development of a novel therapeutic means to treat this hard-to-cure cancer. Dye-swap experiment, vector control vs. stable TTF-1 transfectant of HPL1D, immortalized human peripheral lung epithelial cell line.