The results suggest that expression of CD44 in these cutaneous epithelial tumors is not related to malignant transformation, but instead may be related to tumor progression and the ability to metastasize.
This article summarizes briefly the present knowledge on known functions of CD44 isoforms with particular focus on parallels between physiological programs and tumor progression.
Expression of CD44, particularly of certain splice variants, has been linked to tumor progression and metastatic potential in a number of different animal and human cancers.
The expression of some CD44 isoforms has been shown to be involved in tumor progression and metastatic spread in a rat carcinoma model and in human carcinomas.
Because human cutaneous melanoma is among the most aggressive human cancers, we explored expression of CD44 isoforms (CD44v) in lesions of melanocytic tumor progression.
Expression of none of the CD44 variant epitopes was found to be positively correlated with tumour progression or with colorectal tumour metastasis to the liver, results which are inconsistent with a role for CD44 variants as indicators of colonic cancer progression.
In cutaneous melanoma, the standard CD44 molecule is abundantly expressed, whereas the expression of certain splice variants is related to tumour progression and to the metastatic potential of the cell line.
CD44 alternative splicing patterns differ between normal and malignant tissue, and accordingly, modulation of CD44 splicing has received the most attention in studies that have examined the role of CD44 in tumor progression.
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.
Functional and correlative data implicate a role of CD44 variant isoforms in adhesion dependent processes such as lymphocyte recirculation and tumor progression and metastasis.
These findings indicate that in endometrial carcinomas, expression of individual variant CD44 exons is markedly up-regulated, but this molecule may not be useful as a consistent indicator of tumor progression.
In this study we examined the relationships of cancer progression with mRNA levels of RHAMM, CD44 (all forms), and exon 6 of CD44 using the real-time reverse transcriptase-polymerase chain reaction method in specimens of colon cancers at different diagnostic stages from 30 patients.
Down-regulation of the cell-surface adhesion molecule CD44 has been suggested to play an important role in tumor progression and metastasis of prostate cancer.
CD44 variant proteins have been implicated in tumor progression and metastasis, and a correlation with adverse prognosis has been demonstrated in a variety of human tumors.
CD44 is an adhesion molecule involved in many biological functions and has been described to play a role in tumor progression as well as in promotion of metastasis.