Project description:Tumor cells that give rise to metastatic disease are a primary cause of cancer-related death and have not been fully elucidated in patients with lung cancer. Here, we addressed this question by using tissues from a mouse that develops metastatic lung adenocarcinoma owing to expression of mutant K-ras and p53. We identified a metastasis-prone population of tumor cells that differed from those with low metastatic capacity on the basis of having sphere-forming capacity in Matrigel cultures, increased expression of CD133 and Notch ligands, and relatively low tumorigenicity in syngeneic mice. Knockdown of jagged1 or pharmacologic inhibition of its downstream mediator phosphatidylinositol 3-kinase abrogated the metastatic but not the tumorigenic activity of these cells. We conclude from these studies on a mouse model of lung adenocarcinoma that CD133 and Notch ligands mark a population of metastasis-prone tumor cells and that the efficacy of Notch inhibitors in metastasis prevention should be explored. Keywords: two group comparison 344SQ subcutaneous tumors (from a lung adenocarcinoma cell line derived from a KrasLA1/+; p53R172HdelG/+ mouse that metastasizes widely following subcutaneous injection into syngeneic mice) were sorted by flow cytometry into CD133high and CD133low fractions. RNA samples from these fractions were processed and analyzed on Affymetrix Mouse Expression Array 430A 2.0 chips.
Project description:Tumor cells that give rise to metastatic disease are a primary cause of cancer-related death and have not been fully elucidated in patients with lung cancer. Here, we addressed this question by using tissues from a mouse that develops metastatic lung adenocarcinoma owing to expression of mutant K-ras and p53. We identified a metastasis-prone population of tumor cells that differed from those with low metastatic capacity on the basis of having sphere-forming capacity in Matrigel cultures, increased expression of CD133 and Notch ligands, and relatively low tumorigenicity in syngeneic mice. Knockdown of jagged1 or pharmacologic inhibition of its downstream mediator phosphatidylinositol 3-kinase abrogated the metastatic but not the tumorigenic activity of these cells. We conclude from these studies on a mouse model of lung adenocarcinoma that CD133 and Notch ligands mark a population of metastasis-prone tumor cells and that the efficacy of Notch inhibitors in metastasis prevention should be explored. Keywords: two group comparison
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:We have identified the histone methyltransferases G9a/Glp as suppressors of aggressive lung tumor-propagating cells (TPCs). Chemically inhibiting G9a/Glp promoted TPC phenotypes in lung adenocarcinoma cells, and caused chromatin changes at genes associated with the differentiation of stem cells. G9a/Glp inhibition in lung progenitor cell organoid cultures disrupted alveolar differentiation. Depleting G9a during tumorigenesis enriched for TPCs, accelerating disease progression and metastasis. Demethylase inhibition decreased lung adenocarcinoma progression in vivo.
Project description:We have identified the histone methyltransferases G9a/Glp as suppressors of aggressive lung tumor-propagating cells (TPCs). Chemically inhibiting G9a/Glp promoted TPC phenotypes in lung adenocarcinoma cells, and caused chromatin changes at genes associated with the differentiation of stem cells. G9a/Glp inhibition in lung progenitor cell organoid cultures disrupted alveolar differentiation. Depleting G9a during tumorigenesis enriched for TPCs, accelerating disease progression and metastasis. Demethylase inhibition decreased lung adenocarcinoma progression in vivo.
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.
Project description:Sustained tumor progression has been attributed to a distinct population of tumor-propagating cells (TPCs). To identify TPCs relevant to lung cancer pathogenesis, we investigated functional heterogeneity in tumor cells isolated from Kras-driven mouse models of non-small cell lung cancer (NSCLC). CD24+ITGB4+Notchhi cells are capable of propagating tumor growth in both a clonogenic and an orthotopic serial transplantation assay. While all four Notch receptors mark TPCs, Notch3 plays a non-redundant role in tumor cell propagation in two mouse model and in human NSCLC. The TPC population is enriched after chemotherapy and the gene signature of mouse TPCs correlates with poor prognosis in human NSCLC. The unique role of Notch3 in tumor propagation may provide a therapeutic target for NSCLC Primary lung adenocarcinoma tumor cells were FACS sorted based on expression of CD24, ITGB4 and Notch. TPC cells are defined by Cd24+ITGB4+ Notch(high), and the remainder tumor cells are non-TPC cells. Samples were derived from six mice.
Project description:Lung cancer is the leading cause of cancer death worldwide. Brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker in epithelial-mesenchymal transition) and ADAM9 (a member of type I transmembrane proteins) have been reported relating to lung cancer brain metastasis, however, it is still not clear whether any interaction between them to mediate lung cancer brain metastasis. Since microRNAs were discovered to regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9 regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and immunoblotting proved that CDH2 was a target gene of miR-218. The expression of miR-218 was generated from pri-mir-218-1, located in SLIT2, in low invasive lung adenocarcinoma while it was inhibited in aggressive lung adenocarcinoma. Down-regulation of ADAM9 could up-regulate SLIT2 and miR-218, thus down-regulate CDH2 expression. This study elucidated the mechanism of ADAM9 activating CDH2 may be due to release the inhibition of miR-218 on CDH2 in lung adenocarcinoma. For each of the cell lines bm#2, bm#7, and F4, one microarray was analyzed.
Project description:Lung cancer is the leading cause of cancer death worldwide. Brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker in epithelial-mesenchymal transition) and ADAM9 (a member of type I transmembrane proteins) have been reported relating to lung cancer brain metastasis, however, it is still not clear whether any interaction between them to mediate lung cancer brain metastasis. Since microRNAs were discovered to regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9 regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and immunoblotting proved that CDH2 was a target gene of miR-218. The expression of miR-218 was generated from pri-mir-218-1, located in SLIT2, in low invasive lung adenocarcinoma while it was inhibited in aggressive lung adenocarcinoma. Down-regulation of ADAM9 could up-regulate SLIT2 and miR-218, thus down-regulate CDH2 expression. This study elucidated the mechanism of ADAM9 activating CDH2 may be due to release the inhibition of miR-218 on CDH2 in lung adenocarcinoma. For each of the cell lines bm#2, bm#7, and F4, one microarray was analyzed.
Project description:Metastasis suppressor 1 (MTSS1) is a 755 amino acid protein found in the cell cytoplasm which binds to actin and promotes cytoskeleton organization and is a known suppressor of lung adenocarcinoma metastasis This study demonstrated that preservation of MTSS1 protein expression in lung adenocarcinoma was associated with a 20% 5-year survival advantage in patients. Furthermore, overexpression of MTSS1 was found to reduce metastasis and disease progression in an in-vivo orthotopic lung adenocarcinoma mouse model. Nuclear factor kappa B (NF-kB), an important nuclear transcription factor, has been shown to be constitutively active in lung adenocarcinoma and strongly associated with the development of metastasis. The NF-kB RelA/p65 subunit is involved in NF-kB heterodimer formation and subsequent nuclear translocation leading to activation of NF-kB responsive gene transcription. Phosphorylation and acetylation of p65 are critical post-translational modifications required for NF-kB activation. In this study, we demonstrate that MTSS1 expression leads to decreased NF-κB mediated gene transcription through inhibition of p65 phosphorylation. These findings uncover a novel mechanism through which MTSS1 may regulate lung adenocarcinoma metastasis by impairment of NF-κB regulated gene transcription.