A NOTCH3-mediated squamous cell differentiation program limits expansion of EMT-competent cells that express the ZEB...

Area of Science:

• Molecular Biology
• Cancer Research
• Cell Signaling

Background:

• Zinc finger E-box-binding (ZEB) proteins (ZEB1, ZEB2) drive senescence, epithelial-to-mesenchymal transition (EMT), and cancer stem cell functions.
• ZEB protein regulation involves the miR-200 microRNA family, but their emergence during invasive growth is not fully understood.
• NOTCH3-mediated signaling's role in preventing the expansion of ZEB-expressing cells is a novel area of investigation.

Purpose of the Study:

• To investigate the mechanism by which NOTCH3 signaling controls the expansion of ZEB-expressing cells.
• To elucidate the role of Notch signaling in cell fate regulation and disease progression in esophageal squamous cancers.
• To understand how ZEB expression emerges during invasive growth.

Main Methods:

• Utilized human esophageal cells to study ZEB expression and NOTCH3-mediated squamous differentiation.
• Employed genetic inhibition of Notch signaling using dominant-negative Mastermind-like 1 (DNMAML1).
• Performed RNA interference experiments and utilized organotypic three-dimensional culture for invasive growth modeling.

Main Results:

• NOTCH3 signaling was found to prevent the expansion of a specific subset of ZEB-expressing cells.
• Inhibition of Notch signaling (via DNMAML1) led to impaired squamous differentiation, ZEB upregulation, miR-200 downregulation, and enhanced anchorage-independent growth.
• ZEBs were implicated in anchorage-independent colony formation, invasion, and TGF-β-mediated EMT.

Conclusions:

• NOTCH3 acts as a critical regulator limiting the expansion of ZEB-expressing cells in esophageal contexts.
• The study provides mechanistic insights into Notch signaling's role in cell fate and esophageal squamous cancer progression.
• Findings highlight the interplay between Notch, ZEBs, and EMT in invasive tumor growth.