Paiva P et al. (2005) Expression patterns of hyaluronan, hyaluronan synthases and hyaluronidases indicate a role for hyaluronan in the progression of endometrial cancer. Gynecol Oncol 98: 193–202

There is increasing evidence for the role of the extracellular glycosaminoglycan hyaluronan (HA) and its degradative enzymes hyaluronidases (Hyal) in tumor progression. HA is thought to facilitate tumor metastasis by promoting tumor-cell adhesion and migration. Hyal might enhance tumor invasion by facilitating extracellular matrix degradation and tumor angiogenesis. Elevated levels of HA and Hyal have been found in a range of tumors, including those of the prostate, breast and bladder.

This study analyzed the expression and cellular localization of HA and its synthase enzymes, together with the mRNA expression of Hyal, in 39 samples of endometrial cancer of varying histological grade. HA, its synthases and degradative enzymes were identified in all endometrial cancers. Histochemical analysis showed that HA was predominantly localized to tumor stroma. Levels increased with tumor grade, although this was significant only in Grade 2 carcinomas. HA staining intensity correlated with extent of myometrial invasion. HA synthase was localized mainly to tumor epithelial cells, and levels did not vary with tumor grade. Real-time reverse transcription polymerase chain reaction showed Hyal 3 to be the most abundant isozyme, followed by Hyal 2, with Hyal 1 the least abundant. There was no variation with tumor grade in the mRNA levels of any of the Hyal isozymes.

Although further studies are needed to fully understand the role of HA in tumorigenesis, these results suggest that elevated HA has a possible role in endometrial cancer progression and could offer potential as a prognostic marker.