Hyaluronan synthases (HAS1-3) and hyaluronidases (HYAL1-2) in the accumulation of hyaluronan in endometrioid endometrial carcinoma

Abstract

BackgroundHyaluronan accumulation correlates with the degree of malignancy in many solid tumor types, including malignant endometrial carcinomas. To elucidate the mechanism of hyaluronan accumulation, we examined the expression levels of the hyaluronan synthases (HAS1, HAS2 and HAS3) and hyaluronidases (HYAL1 and HYAL2), and correlated them with hyaluronan content and HAS1-3 immunoreactivity.MethodsA total of 35 endometrial tissue biopsies from 35 patients, including proliferative and secretory endometrium (n = 10), post-menopausal proliferative endometrium (n = 5), complex atypical hyperplasia (n = 4), grade 1 (n = 8) and grade 2 + 3 (n = 8) endometrioid adenocarcinomas were divided for gene expression by real-time RT-PCR, and paraffin embedded blocks for hyaluronan and HAS1-3 cytochemistry.ResultsThe mRNA levels of HAS1-3 were not consistently changed, while the immunoreactivity of all HAS proteins was increased in the cancer epithelium. Interestingly, HAS3 mRNA, but not HAS3 immunoreactivity, was increased in post-menopausal endometrium compared to normal endometrium (p = 0.003). The median of HYAL1 mRNA was 10-fold and 15-fold lower in both grade 1 and grade 2+3 endometrioid endometrial cancers, as compared to normal endometrium (p = 0.004-0.006), and post-menopausal endometrium (p = 0.002), respectively. HYAL2 mRNA was also reduced in cancer (p = 0.02) and correlated with HYAL1 (r = 0.8, p = 0.0001). There was an inverse correlation between HYAL1 mRNA and the epithelial hyaluronan staining intensity (r = -0.6; P = 0.001).ConclusionThe results indicated that HYAL1 and HYAL2 were coexpressed and significantly downregulated in endometrioid endometrial cancer and correlated with the accumulation of hyaluronan. While immunoreactivity for HASs increased in the cancer cells, tumor mRNA levels for HASs were not changed, suggesting that reduced turnover of HAS protein may also have contributed to the accumulation of hyaluronan.

Influence of hyaluronan on endometrial receptivity and embryo attachment in sheep

“…In the control group, immunostaining of HA using HABP revealed that on Day 17 of pregnancy HA is localised only in the ST of the ovine endometrium, while the LE and GE were devoid of HA staining. A similar pattern of HA localisation was observed in the endometrium of the ewe in our previous report during different stages of the oestrous cycle (Raheem et al 2013) as well as in mouse (Teixeira Gomes et al 2009) and human (Afify et al 2006;Nykopp et al 2010) endometrium. In the present study, uterine infusion with HA resulted in a positive staining of HA on the LE, suggesting that the infused HA can bind to the LE, possibly through hyaladherins like CD44, which was also found to be expressed.…”

Regulation of the hyaluronan system in ovine endometrium by ovarian steroids

“…We also observed downregulation Steroid regulation of HA in endometrium of progesterone nuclear receptors in the OVXP and OVXEP groups compared with the OVX group in the present experiment (data not shown) and this may explain the difference in HAS3 expression pattern. However, HAS3 protein expression was increased in the endometrium under progesterone dominance in both the LUT and OVXP groups and it is known that HAS3 mRNA expression is sometimes not correlated with HAS3 immunoreactivity (Nykopp et al 2010). HA has a high rate of turnover at both the cellular and the tissue levels mainly due to enzymatic hydrolysis by HYALs that include HYAL1, HYAL2, HYAL3, HYAL4, HYALP1, and PH-20.…”

“…The HA level in the endometrium may also be used as an indicator to the physiological or pathological status of this organ (Nykopp et al 2010). High-molecular-weight (HMW) HA produced by HAS2 is so crucial for mammalian embryogenesis that HAS2-knockout embryos die in mid-gestation due to cardiac and vascular abnormalities (Camenisch et al 2000).…”

Localisation and endocrine control of hyaluronan synthase (HAS) 2, HAS3 and CD44 expression in sheep granulosa cells

“…For example, HAS was detected using immunohistochemistry in pig ovary (Miyake et al 2009), ovine cervix (Perry et al 2012) and uterus (Raheem et al 2013) and human endometrium (Nykopp et al 2010). In addition, the HA receptor (CD44) was immunolocalised in ovine cervix (Perry et al 2010) and uterus (Raheem et al 2013), pig ovary (Miyake et al 2006) and oviduct (Tienthai et al 2003), bovine oocytes, embryos and oviduct (Ulbrich et al 2004;Marei et al 2012;Marei et al 2013), cumulus and mural granulosa (Ohta et al 1999;Marei et al 2012) and cervical cells (El Maradny et al 1997).…”