Project description:YAP and TAZ play oncogenic roles in various organs, but the role of YAP/TAZ activation in gastric cancer in vivo has been understudied. We investigated whether and how YAP/TAZ initiates gastric tumorigenesis in vivo and its significance in human gastric cancer. We studied Lats1fl/fl;Lats2fl/fl;Lgr5-CreER mice, which have activated YAP/TAZ in pyloric stem cells. Gastric tissues were collected and analyzed by histopathology and immunostaining. To scrutinize the molecular mechanisms, we performed RNA sequencing in gastric tissue samples. Tissue microarray and public transcriptome data were analyzed to investigate the importance of YAP/TAZ in human gastric cancer.
Project description:The goal of the project is to analyze different layers of proteome information including protein abundance and post-translational modifications of PGRC gastric tissue samples. Three pairs of human gastric cancer and adjacent normal tissues were extensively characterized by serial enrichments of phosphorylation and N-glycosylation (SEPG) coupled to LC-MS/MS method.
Project description:Lats1 and Lats2 are the mediators of the Hippo pathway that regulates tissue growth and proliferation. Lats1 and Lats2 kinases share 85% sequence identity in the kinase domain. However, their non-kinase regions at the N-terminus are distinct except for Lats conserved domain 1 (LCD1) and LCD2, suggesting that their N-terminal regions are important for Lats1/2-specific functions. In this study, we generated Lats1 knockout mice disrupting the N-terminal region containing LCD1 (Lats1M-NM-^TN/M-NM-^TN). We show that some Lats1M-NM-^TN/M-NM-^TN mice were born safely and grew normally. However, mouse embryonic fibroblasts (MEFs) from Lats1M-NM-^TN/M-NM-^TN mice displayed drastic defects in mitosis, showing enhanced centrosome overduplication, chromosomal misalignment, multipolar spindle formation, chromosome bridging, and cytokinesis failure. Moreover, they displayed accelerated cell cycle and cell growth bypassing a cell-cell contact inhibition like tumor cells, and exhibited anchorage independent growth. Indeed, Lats1M-NM-^TN/M-NM-^TN MEFs produced tumors in nude mice after subcutaneous injection, although the tumor growth rate was much slower than ordinary cancer cells. Furthermore, Yap, the key transcriptional co-activator in the Hippo pathway, was overexpressed and retained stable in Lats1M-NM-^TN/M-NM-^TN MEFs under high cell density, and expression of Lats2 mRNA were down-regulated. Total RNAs were extracted from MEFs under high or low cell density using miRNeasy extraction kit (Qiagen). A Dye-swapped experiment was performed by hybridizing complimentary RNA (cRNA) labeled with either Cyanine (Cy) -3 or Cy-5 (Perkin-Elmer) onto Whole Mouse Genome Oligo Microarray (G4122F; Agilent Technologies). Co-hybridizations were performed and data from Cy3 or Cy5 channels were analyzed as normalized signal intensities rather than as log ratios corresponding to each array.
Project description:LATS1/2 are canonical Hippo signaling pathway components. Our genome-wide screen indicated a synthetic viable effect of Hippo pathway inhibition in ATM-depleted human embryonic and neural progenitor cells. This experiment was designed in order to get mechanistic insights regarding the molecular effect of Hippo pathway inhibition on ATM-knockout cells. Such chemical inhibition could potentially be used as a means to impede Ataxia-Telangiectasia-related neurodegeneration. Experimental procedure: 2 clones of ATM-knockout h-pES10 cells were plated on 6 well plates with MEFs feeder layer. 1 d after plating, medium was replaced with standard medium (as control) or medium containing 10 µM of LATS1/2 inhibitor, TRULI (Lats-IN-1) for 24 h. Cells were then harvested, total RNA was extracted, libraries for RNA sequencing were generated and sequenced. Total reads were mapped to human GRCh38 reference genome, and to mouse GRCm38 using STAR package. XenofilteR package in R was used to filter out mouse-originated reads. Count tables and differential analysis were performed using EdgeR package in R.
Project description:Human primary gastric cancer tissue SAGE libraries. Profile of the genes expressed in well and poorly differentiated gastric cancer, early and advanced gastric cancer, scirrhous type gastric cancer, and lymph node metastasis determined through SAGE. Keywords = gastric cancer, histology, early gastric cancer, advanced gastric cancer, lymph node metastasis, scirrhous type gastric cancer Keywords: other
Project description:Chronic infection with the bacterial pathogen Helicobacter pylori is a risk factor for the development of gastric cancer, yet remains asymptomatic in a majority of individuals. We report here that the C57Bl6 mouse model of experimental infection with the closely related H. felis recapitulates this wide range in host susceptibility. A majority of infected mice develop premalignant lesions such as gastric atrophy, compensatory epithelial hyperplasia and intestinal metaplasia, whereas a minority is completely protected from preneoplasia. Protection is associated with the failure to mount an IFN-gamma response to the infection and an associated high Helicobacter burden. We demonstrate that IFN-gamma is essential for clearance of Helicobacter, but also mediates the formation of preneoplastic lesions. We further provide evidence that IFN-gamma triggers a specific transcriptional program in murine gastric epithelial cells in vitro and in vivo, and induces their preferential transformation to the hyperplastic phenotype. In summary, our data suggest a dual role for IFN-gamma in Helicobacter pathogenesis that could provide an explanation for the differential susceptibility to H. pylori-induced gastric pathology in the human population. Keywords: response to in vitro stimulus / comparison of histopathological states We chose mice for gene expression profiling that following Helicobacter infection had (a) symptoms of gastritis, but no epithelial changes, (b) atrophic gastritis accompanied by corpus gland hyperplasia or (c) atrophic gastritis accompanied by intestinal metaplasia. An uninfected control group was also included in the analysis, as were two groups of mice that lacked mature T- and B-cells due to a deletion mutation in the rag1 gene (Rag-1-/-) and that were either experimentally infected or served as Rag-1-/- uninfected controls. To see the effects of IFNg on murine gastric epithelial cells we analysed an immortalized murine primary gastric epithelial cell line treated with three different concentrations of IFNg in comparison to an untreated control.
Project description:LATS1/2 is frequently mutated and down-regulated in endometrial cancer (EC), but the contribution of LATS1/2 to endometrial tumor progression remains unclear. Here, we discovered an unexpected role of LATS1/2 in regulating MHC class I expression in EC. We demonstrate that the knockout of LATS1/2 in EC cells resulted in significant down-regulation of multiple genes of MHC/HLA Class I family and leaded to insensitivity to tumor immunotherapy. Furthermore, we found that the regulation of LATS1/2 on MHC/HLA expression does not depend on the classical Hippo pathway but on their direct interaction with STAT1 to phosphorylate STAT1 to promote STAT1 accumulating and moving into the nucleus to enhance the transcriptional activation of IRF1/NLRC5 on MHC-I. The kinase-dead mutant LATS1/2 attenuates STAT1 phosphorylation at Ser727. The expressions of LATS1/2, MHC-I, CD8A and p-STAT1(S727)are positive correlation in tissues of EC confirming our findings furtherly. Furthermore, LATS1/2 expression was negatively correlated with tumor stage in EC tissues. These findings reveal novel molecular mechanisms underlying tumor immunogenicity deficiency and elucidate the potential immunotherapy biomarker targeting LATS1/2 in EC.
Project description:Lats1 and Lats2 are the mediators of the Hippo pathway that regulates tissue growth and proliferation. Lats1 and Lats2 kinases share 85% sequence identity in the kinase domain. However, their non-kinase regions at the N-terminus are distinct except for Lats conserved domain 1 (LCD1) and LCD2, suggesting that their N-terminal regions are important for Lats1/2-specific functions. In this study, we generated Lats1 knockout mice disrupting the N-terminal region containing LCD1 (Lats1ΔN/ΔN). We show that some Lats1ΔN/ΔN mice were born safely and grew normally. However, mouse embryonic fibroblasts (MEFs) from Lats1ΔN/ΔN mice displayed drastic defects in mitosis, showing enhanced centrosome overduplication, chromosomal misalignment, multipolar spindle formation, chromosome bridging, and cytokinesis failure. Moreover, they displayed accelerated cell cycle and cell growth bypassing a cell-cell contact inhibition like tumor cells, and exhibited anchorage independent growth. Indeed, Lats1ΔN/ΔN MEFs produced tumors in nude mice after subcutaneous injection, although the tumor growth rate was much slower than ordinary cancer cells. Furthermore, Yap, the key transcriptional co-activator in the Hippo pathway, was overexpressed and retained stable in Lats1ΔN/ΔN MEFs under high cell density, and expression of Lats2 mRNA were down-regulated.