We investigated the expression of CD44 and RHAMM in tissue samples of endometrial cancer and the relation of their expression with clinicopathologic parameters of patients.
To address this, the expression of CD44 (both standard and variants, designated CD44s and CD44v, respectively) was evaluated in human dermal fibroblasts (HDFs) and a large panel of cancer cell lines, including breast, prostate, head and neck, pancreatic, ovarian, colorectal, thyroid, and endometrial cancers.
Significantly increased concentration in EC as compared to healthy controls were found in case of CD44 (p < 0.001), EpCAM (p = 0.033) and TGM2 (p < 0.001).
Furthermore, patient samples (hormone-treated endometria, hyperplasia, and endometrial cancer) were stained for Wnt activation using nuclear beta-catenin and CD44.
Furthermore, in advanced endometrial cancer, it was shown that loss of expression of both PR and E-cadherin was associated with increased expression CD44 and CSPG/Versican.
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 immunohistochemical staining, CD44 V6 and V7 were detected in 48 and 61% of endometrial cancers and in 26 and 42% of normal endometrial samples, respectively.
Significantly elevated levels of CD44 expression in endometrial carcinomas compared with the proliferative phase and hyperplasia were also revealed by both the immunohistochemical and the RT-PCR/SBH assays, while no association was noted with any prognostic factors.
The standard form of CD44 was expressed in all specimens and 20 out of 42 endometrial cancers expressed an isoform containing exon v6 in combination with other variant exons.
Variant forms of CD44 were expressed in 9 of 11 (81.8%) normal endometria, whereas 8 of 47 (17.0%) endometrial carcinomas showed expression of the variants.