CD44 is a major cell surface adhesion molecule for hyaluronan, a component of the extracellular matrix, and is implicated in tumor metastasis and invasion.
In contrast, the semiquantitatively scored membrane-bound staining of CD 44-S was stronger in tumors without metastases (mean 2.1 vs mean: 0.25) during the follow-up period (P<0.01).
During 3 years of follow-up, 2 patients whose peripheral blood had carcinoembryonic antigen and CD44 variant mRNA also had distant metastases (lung or spleen).
In two of 10 hormone-refractory cases, a comparison of the methylation status of the CD44 gene in metastases to that in primary tumors revealed interfocal heterogeneity of CD44 methylation status.
CD44 is a transmembrane glycoprotein involved in various cell adhesion events, including lymphocyte migration, early hemopoiesis, and tumor metastasis.
However, CD44(+) cancer cells are also present in some primary tumors; and in some metastases, they, and not CD57(+) cells, constitute a predominant population.
CD44 expression was characterised in a closely matched series of oral carcinomas with and without metastases in both frozen and formalin-fixed tissue and correlated with behaviour and histological grading parameters.
Many studies have investigated the pattern of CD44 distribution in tumours and some observations suggest that certain cells do not use CD44 in tumorigenesis or in the production of metastases.
Since the CD44 variant 6(v6) molecule has been noted as a marker for tumor metastasis and prognosis in several tumors, we examined whether or not v6 is a useful marker for evaluating the prognosis of pancreatic cancer patients.
Metastases were not detected in nude mice inoculated with antisense CD44 exon 10 (v6)-expressing cell lines after 4 months, against a background of a 30% metastasis rate in the control HT29 parental and vector alone transfected lines.
Recent studies have shown that some variant forms of CD44, a transmembrane glycoprotein expressed on various cell surfaces, might be involved in tumor progression or tumor metastasis.