NKX2-1 occupancy in human lung adenocarcinoma cell lines
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ABSTRACT: The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To better understand how genomic alterations of NKX2-1 drive tumorigenesis, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma, and analyzed DNA binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation from NKX2-1-amplified human lung adenocarcinoma cell lines. Combining these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1, in addition to consensus binding motifs including a nuclear hormone receptor signature and a Forkhead box motif in NKX2-1-bound sequences. RNA interference analysis of NKX2-1-amplified cells compared to non-amplified cells demonstrated that LMO3 mediates cell proliferation downstream of NKX2-1; cistromic analysis that NKX2-1 may cooperate with FOXA1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transducer of lineage specific cell survival of NKX2-1-amplified lung adenocarcinomas.
Project description:The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To better understand how genomic alterations of NKX2-1 drive tumorigenesis, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma, and analyzed DNA binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation from NKX2-1-amplified human lung adenocarcinoma cell lines. Combining these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1, in addition to consensus binding motifs including a nuclear hormone receptor signature and a Forkhead box motif in NKX2-1-bound sequences. RNA interference analysis of NKX2-1-amplified cells compared to non-amplified cells demonstrated that LMO3 mediates cell proliferation downstream of NKX2-1; cistromic analysis that NKX2-1 may cooperate with FOXA1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transducer of lineage specific cell survival of NKX2-1-amplified lung adenocarcinomas. NKX2-1 ChIP-seq from three lung adenocarcinoma cell lines with amplification of NKX2-1
Project description:The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To better understand how genomic alterations of NKX2-1 drive tumorigenesis, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma, and analyzed DNA binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation from NKX2-1-amplified human lung adenocarcinoma cell lines. Combining these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1, in addition to consensus binding motifs including a nuclear hormone receptor signature and a Forkhead box motif in NKX2-1-bound sequences. RNA interference analysis of NKX2-1-amplified cells compared to non-amplified cells demonstrated that LMO3 mediates cell proliferation downstream of NKX2-1; cistromic analysis that NKX2-1 may cooperate with FOXA1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transducer of lineage specific cell survival of NKX2-1-amplified lung adenocarcinomas.
Project description:The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To better understand how genomic alterations of NKX2-1 drive tumorigenesis, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma, and analyzed DNA binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation from NKX2-1-amplified human lung adenocarcinoma cell lines. Combining these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1, in addition to consensus binding motifs including a nuclear hormone receptor signature and a Forkhead box motif in NKX2-1-bound sequences. RNA interference analysis of NKX2-1-amplified cells compared to non-amplified cells demonstrated that LMO3 mediates cell proliferation downstream of NKX2-1; cistromic analysis that NKX2-1 may cooperate with FOXA1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transducer of lineage specific cell survival of NKX2-1-amplified lung adenocarcinomas. NCI-H2009 cells with stable expression of either pLKO-Tet-Op-shGFP (n=4) or pLKO-Tet-Op-shNKX2-1 (pooled population; n=3 and a clone; n=3) were treated with 50ng/ml of doxycyline for 48 hours. Total RNA was extracted, gene expression profiling was performed and differential gene expression between shGFP and shNKX2-1 was analyzed to determine the effects by suppression of NKX2-1 in NCI-H2009 cells.
Project description:Tissue-specific differentiation programs become dysregulated during cancer evolution. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and by inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 causes transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs are required for tumors to reach a primitive, dedifferentiated state. ChIP-seq data from murine lung adenocarcinomas on (i) transcription factors Nkx2-1 and Foxa in Nkx2-1-deleted tumors and Nkx2-1-positive control tumors, and (ii) four histone marks in Nkx2-1-deleted tumors and Nkx2-1-positive control tumors. (All samples in duplicate and with input controls, i.e. (2 x [(3+3) + (2+8)]) - 1 = 31 samples total - 1 input control used for transcription factor and histone mark, GSM1059357)
Project description:Tissue-specific differentiation programs become dysregulated during cancer evolution. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and by inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 causes transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs are required for tumors to reach a primitive, dedifferentiated state.
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: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.
Project description:During cancer evolution, cellular differentiation programs become dysregulated. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 results in transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs may be required for tumors to reach a primitive, dedifferentiated state. The study was designed to compare the expression profiles of Nkx2-1-positive lung adenocarcinomas with tumors in which Nkx2-1 was deleted at the time of initiation or 6-7 months after initiation.
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:During cancer evolution, cellular differentiation programs become dysregulated. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 results in transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs may be required for tumors to reach a primitive, dedifferentiated state.