CD44 enhances tumor aggressiveness by promoting tumor cell plasticity

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Tumor cells can transdifferentiate into endothelial-like cells, forming vasculogenic networks (VM).
• Vasculogenic mimicry (VM) is linked to increased tumor malignancy and poor patient prognosis.
• Identifying key molecular drivers of VM is crucial for understanding tumor aggressiveness.

Purpose of the Study:

• To identify novel molecular players involved in the vasculogenic mimicry (VM) process.
• To investigate the role of CD44 in VM and tumor aggressiveness.
• To elucidate the CD44/c-Met signaling pathway in VM.

Main Methods:

• Microarray analysis to compare gene expression profiles of aggressive (VM+) and non-aggressive (VM-) tumor cells.
• Functional analyses in Ewing sarcoma (EW7) cells, including CD44 knockdown and overexpression studies.
• Assessment of CD44 expression in human Ewing sarcoma tissues.

Main Results:

• The CD44/c-Met signaling cascade was identified as critical for VM.
• CD44, particularly standard and CD44v6 isoforms, was highly overexpressed in aggressive (VM+) cells and tumors.
• CD44 overexpression enhanced cell adhesion to hyaluronic acid and promoted in vitro vascular network formation; CD44 knockdown inhibited migration and VM.

Conclusions:

• CD44 plays a significant role in promoting tumor aggressiveness via vasculogenic mimicry (VM).
• CD44 facilitates VM by enhancing cell adhesion and migration, leading to vascular network formation.
• CD44 is a potential therapeutic target for aggressive tumors exhibiting VM.