CD44 and HCELL: preventing hematogenous metastasis at step 1.

Area of Science:

• Oncology
• Molecular Biology
• Cell Biology

Background:

• Metastasis causes over 90% of cancer deaths, yet its molecular drivers remain largely unknown.
• Understanding cancer cell metastasis is crucial for developing effective treatments.
• Circulating tumor cells (CTCs) appear to utilize normal leukocyte trafficking pathways to reach distant sites.

Purpose of the Study:

• To review the structural biology of CD44 and HCELL.
• To present current data on the function of CD44 and HCELL in CTC homing and organ-specific metastasis.
• To elucidate the molecular mechanisms underlying cancer metastasis.

Main Methods:

• Literature review focusing on structural biology and functional data of CD44 and HCELL.
• Analysis of existing evidence on selectin ligand function in cancer cell trafficking.
• Integration of knowledge on leukocyte and tumor cell homing mechanisms.

Main Results:

• CD44 is characteristically expressed on cancer cells.
• Hematopoietic cell E-/L-selectin ligand (HCELL), a CD44 variant, acts as a key selectin ligand on cancer cells.
• HCELL mediates interactions between tumor cells, endothelium, leukocytes, and platelets, facilitating organ-specific metastasis.

Conclusions:

• CD44 and HCELL play critical roles in the organ-specific homing of circulating tumor cells.
• Hijacking leukocyte trafficking mechanisms by cancer cells involves CD44 and HCELL.
• Further research into these molecules could reveal novel therapeutic targets for preventing cancer metastasis.