Notch Mediates Inter-tissue Communication to Promote Tumorigenesis

Area of Science:

• Developmental Biology
• Cancer Biology
• Cell Signaling

Background:

• Tumor progression involves complex interactions between cancer cells and their microenvironment.
• Understanding cell-to-cell communication is crucial for deciphering tumorigenesis mechanisms.
• The Drosophila EGFR-driven tumor model offers a simplified system to study epithelial-mesenchymal cross-talk.

Purpose of the Study:

• To investigate the role of Notch signaling in EGFR-driven tumorigenesis in Drosophila.
• To identify key molecular players mediating communication between transformed epithelial and mesenchymal cells.
• To elucidate the mechanism of long-range signaling in tumor growth.

Main Methods:

• Utilized a Drosophila genetic model of EGFR-driven tumorigenesis.
• Manipulated Notch signaling and its downstream target Zfh1/ZEB in mesenchymal cells.
• Investigated the role of Delta ligand and cellular processes (cytonemes) in epithelial signaling.
• Employed live transcription assays and targeted depletion of cellular processes.

Main Results:

• Transformed epithelial cells utilize Notch signaling to influence mesenchymal cells.
• Notch signaling in mesenchyme prevents differentiation and promotes proliferation, contributing to tumor growth.
• Depletion of Notch signaling or Zfh1/ZEB in mesenchyme compromises tumor growth.
• Delta ligand on epithelial cytonemes mediates long-range signaling to mesenchymal cells.

Conclusions:

• Cancerous epithelial cells co-opt Notch signaling via Delta-expressing cytonemes to manipulate mesenchymal cells.
• This long-range signaling hijacks normal differentiation pathways to promote tumor progression.
• The study reveals a conserved mechanism of inter-tissue communication in tumorigenesis.