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1.  A common p53 mutation (R175H) activates c-Met receptor tyrosine kinase to enhance tumor cell invasion 
Cancer Biology & Therapy  2013;14(9):853-859.
Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive forms of human cancer with poor prognosis due to late diagnosis and metastasis. Common genomic alterations in ESCC include p53 mutation, p120ctn inactivation, and overexpression of oncogenes such as cyclin D1, EGFR, and c-Met. Using esophageal epithelial cells transformed by the overexpression of EGFR and p53R175H, we find novel evidence of a functional link between p53R175H and the c-Met receptor tyrosine kinase to mediate tumor cell invasion. Increased c-Met receptor activation was observed upon p53R175H expression and enhanced further upon subsequent EGFR overexpression. We inhibited c-Met phosphorylation, resulting in diminished invasion of the genetically transformed primary esophageal epithelial cells (EPC-hTERT-EGFR-p53R175H), suggesting that the mechanism of increased invasiveness upon EGFR and p53R175H expression may be the result of increased c-Met activation. These results suggest that the use of therapeutics directed at c-Met in ESCC and other squamous cell cancers.
doi:10.4161/cbt.25406
PMCID: PMC3909554  PMID: 23792586
p53 mutation; c-Met; esophageal cancer; tumor invasion
2.  Isolation and characterization of mouse and human esophageal epithelial cells in 3D organotypic culture 
Nature protocols  2012;7(2):235-246.
This protocol describes the isolation and characterization of mouse and human esophageal epithelial cells and the application of 3D organotypic culture (OTC), a form of tissue engineering. This model system permits the interrogation of mechanisms underlying epithelial-stromal interactions. We provide guidelines for isolating and cultivating several sources of epithelial cells and fibroblasts, as well as genetic manipulation of these cell types, as a prelude to their integration into OTC. The protocol includes a number of important applications, including histology, immunohistochemistry/immunofluorescence, genetic modification of epithelial cells and fibroblasts with retroviral and lentiviral vectors for overexpression of genes or RNA interference strategies, confocal imaging, laser capture microdissection, RNA microarrays of individual cellular compartments and protein-based assays. The OTC (3D) culture protocol takes 15 d to perform.
doi:10.1038/nprot.2011.437
PMCID: PMC3505594  PMID: 22240585
3.  Deletion of p120-catenin results in a tumor microenvironment with inflammation and cancer that establishes it as a tumor suppressor gene 
Cancer cell  2011;19(4):470-483.
Summary
P120ctn interacts with E-cadherin, but no formal proof that p120ctn functions as a bone fide tumor suppressor gene has emerged. We report herein that p120ctn loss leads to tumor development in mice. We have generated a conditional knockout model of p120ctn whereby mice develop pre-neoplastic and neoplastic lesions in the oral cavity, esophagus and squamous forestomach. Tumor derived cells secrete granulocyte macrophage colony stimulating factor (GM-CSF), macrophage colony stimulating factor (M-CSF), monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNFα). The tumors contain significant desmoplasia and immune cell infiltration. Immature myeloid cells comprise a significant percentage of the immune cells present, and likely participate in fostering a favorable tumor microenvironment, including the activation of fibroblasts.
doi:10.1016/j.ccr.2011.02.007
PMCID: PMC3077713  PMID: 21481789
4.  EGFR and mutant p53 expand esophageal cellular subpopulation capable of epithelial-to-mesenchymal transition through ZEB transcription factors 
Cancer research  2010;70(10):4174-4184.
Transforming growth factor (TGF)-β is a potent inducer of epithelial to mesenchymal transition (EMT). However, it remains elusive as to which molecular mechanisms determine the cellular capacity to undergo EMT in response to TGF-β. We have found that both epidermal growth factor receptor (EGFR) overexpression and mutant p53 tumor suppressor genes contribute to enrichment of an EMT-competent cellular subpopulation amongst telomerase-immortalized human esophageal epithelial cells during malignant transformation. EGFR overexpression triggers oncogene-induced senescence, accompanied by induction of cyclin dependent kinase inhibitors p15INK4B, p16INK4A and p21. Interestingly, a subpopulation of cells emerges by negating senescence without loss of EGFR overexpression. Such cell populations express increased levels of zinc finger E-box binding (ZEB) transcription factors ZEB1 and ZEB2, and undergo EMT upon TGF-β stimulation. Enrichment of EMT-competent cells was more evident in the presence of p53 mutation, which diminished EGFR-induced senescence. RNA interference directed against ZEB resulted in induction of p15INK4B and p16INK4A, reactivating the EGFR-dependent senescence program. Importantly, TGF-β-mediated EMT did not take place when cellular senescence programs were activated by either ZEB knockdown or activation of wild-type p53 function. Thus, senescence checkpoint functions activated by EGFR and p53 may be evaded through the induction of ZEB, thereby allowing expansion of an EMT-competent unique cellular subpopulation, providing novel mechanistic insights into the role of ZEB in esophageal carcinogenesis.
doi:10.1158/0008-5472.CAN-09-4614
PMCID: PMC3007622  PMID: 20424117
EGFR; EMT; senescence; ZEB1; ZEB2

Results 1-4 (4)