NOTCH3 knockdown in non-transformed human esophageal cells

ABSTRACT: To determine the role of NOTCH3 in human esophageal epitheila homeostasis/squamous cell differentiation Zinc finger E-box binding (ZEB) proteins ZEB1 and ZEB2 are transcription factors essential in transforming growth factor (TGF)-β-mediated epithelial to mesenchymal transition (EMT), senescence and cancer stem cell maintenance through mutual negative regulation of the microRNA (miR)-200 family members. However, little is known as to how ZEB expressing tumor cells may emerge during invasive growth. We find that canonical Notch signaling prevents expansion of a unique subset of cells expressing ZEBs through NOTCH3 (N3). In primary esophageal squamous cell carcinoma (ESCC), ZEB1 is induced in tumor cells displaying EMT-like dedifferentiation at the invasive front of tumor nests with reciprocal downregulation of the miR-200. ZEB expression was associated with the lack of cellular capability of undergoing squamous differentiation through dysfunction of N3, implicated at the onset of normal esophageal squamous differentiation. Dominant-negative Mastermind-like1 (DNMAML1), a genetic pan-notch inhibitor, prevented CSL-dependent transcription, resulting in suppression of N3 expression and squamous differentiation while enriching EMT competent cells with robust upregulation of ZEBs and downregulation of the miR-200. Such a cell population demonstrated enhanced anchorage independent growth as well as tumor formation in nude mice. RNA interference (RNAi) experiments documented the requirement of ZEBs in TGF-β-mediated EMT. Invasive growth and impaired squamous differentiation was recapitulated upon Notch inhibition in organotypic 3D culture, a form of human tissue engineering. Finally, RNAi experiments revealed N3 as a key factor limiting the expansion of the ZEB expressing cells, providing novel mechanistic insights into the role of Notch signaling in ESCC cell fate regulation and disease progression. NOTCH3 was knockdown stably in immortalized human esophageal keratinocytes EPC2-hTERTstably by lentivirus-mediated gene transfer with shRNA directed against NOTCH3 (Open BiosystemsV2LHS_229748). A scrambled shRNA (Open Biosystems RHS4346) served as acontrol. Cells were stimulated with 0.6 mM calcium chloride to induce squamous cell differentiation for 72 hrs (0.09 mM Calcium Chloride as a unstimulated control) as described in Gastroenterology. 2010 Dec;139(6):2113-23 by Ohashi et al.

ORGANISM(S): Homo sapiens

SUBMITTER: Hiroshi Nakagawa 

PROVIDER: E-GEOD-27424 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress