Homing Associated Cell Adhesion Molecule (HCAM)

The CD44 protein participates in a wide variety of cellular functions including lymphocyte activation, recirculation and homing, hematopoiesis, and tumor metastasis. Transcripts for this gene undergo complex alternative splicing that results in many functionally distinct isoforms, however, the full length nature of some of these variants has not been determined. Alternative splicing is the basis for the structural and functional diversity of this protein, and may be related to tumor metastasis. Splice variants of CD44 on colon cancer cells display the HCELL glycoform, which mediates binding to vascular E-selectin under hemodynamic flow conditions, a critical step in colon cancer metastasis. CD44 gene transcription is at least in part activated by beta-catenin and Wnt signalling.