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.