Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Characteristic behaviors of head and neck squamous cell carcinoma (HNSCC) include a propensity to occur as multiple synchronous and metachronous tumors, frequent recurrence and metastasis. Early detection of HNSCC and monitoring its recurrence are necessary to improve prognosis. Hyaluronic acid (HA), a component of extracellular matrix, promotes metastasis. Small fragments of HA stimulate angiogenesis. HA fragments are generated when hyaluronidase (HAase), an endoglycosidase, degrades the HA polymer. Using the HA test (an ELISA-like assay) we found that saliva HA levels are 4.9-fold elevated in 11 HNSCC patients (2841 +/- 887 ng/mg protein) when compared to 6 normal controls (579.3 +/- 122.6 ng/mg protein; p = 0.00238). HNSCC patients included in our study were patients with cancers of the oral cavity (n = 4), pharynx (n = 7) and larynx (n = 1). The HA levels were also elevated in MDA-1483, FaDu and HEp-2 cell lines when compared to the transformed keratinocyte line HEK-001. Saliva HAase levels measured using the HAase test (an ELISA-like assay) were 3.7-fold elevated in HNSCC patients (10.4 +/- 1.4 mU/mg protein) when compared to normal controls (2.8 +/- 0.7 mU/mg protein; p = 0.0028). MDA-1483 and HEp-2 cells secreted 7- to 11-fold higher levels of HAase in their conditioned media (CM) when compared to FaDu cells, and the latter secreted 1.5-fold more HAase than HEK-001 cells. Reverse transcriptase (RT)-PCR analysis detected the expression of full-length HYAL1 type HAase transcript in tumor cells. None of the cells exhibited the expression of PH20 in RT-PCR analysis. Immunoblot analysis confirmed the expression of a approximately 55 kDa HYAL-related protein in tumor cell CM and in patients' saliva. The pH activity profile and optimum (pH 4.4) of the HAase activity present in HNSCC patients' or normal saliva and that secreted in the CM of tumor cells closely resembled that of the partially purified HYAL1 type HAase. The profiles of HA species in HNSCC patients' and normal saliva are different. The high-stage HNSCC patients' saliva contains a high-molecular-mass HA species and HA fragments, in addition to the HA species present in the normal individual's saliva. These results show that HYAL1 is the major tumor-derived HAase expressed in HNSCC. Furthermore, HA and HAase may be sensitive and specific markers for detecting HNSCC and monitoring its recurrence. Further studies are needed to confirm these preliminary studies.
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PMID:Expression of tumor markers hyaluronic acid and hyaluronidase (HYAL1) in head and neck tumors. 1499 92

Hyaluronic acid (HA) is a high molecular weight glycosaminoglycan involved in a wide variety of cellular functions. However, its turnover in living cells remains largely unknown. In this study, CD44, a receptor for HA, and hyaluronidase-1, -2, and -3 (Hyal-1, -2 and -3) were stably expressed in HEK 293 cells and the mechanism of HA catabolism was systematically investigated using fluorescein-labeled HA. CD44 was essential for HA degradation by both endogenous and exogenously expressed hyaluronidases. Hyal-1 was not able to cleave HA in living cells in the absence of CD44. Intracellular HA degradation was predominantly mediated by Hyal-1 after incorporation of HA by CD44. Although Hyal-1 was active only in intracellular space in vivo, a certain amount of the enzyme was secreted to extracellular space. This extracellular Hyal-1 was found to be incorporated by cells and such uptake of Hyal-1 was, in part, involved in the intracellular degradation of HA. Hyal-2 was involved in the extracellular degradation of HA. Hyal-2 activity was also dependent on the expression of CD44 in both living cells and enzyme assays. Immunofluorescent microscopy demonstrated that both Hyal-2 and CD44 are present on the cell surface. Without CD44 expression, Hyal-2 existed in a granular pattern, and did not show hyaluronidase activity, suggesting that localization change could contribute to Hyal-2 function. A convenient and quantitative enzyme assay was established for the measurement of Hyal-2 activity. Hyal-2 activity was detected in the membrane fraction of cells co-expressing Hyal-2 and CD44. The pH optimum for Hyal-2 was 6.0-7.0. The membrane fraction of cells expressing Hyal-2 alone did not show hyaluronidase activity. Hyal-3 did not show any hyaluronidase activity in our experimental conditions. Based on these findings, Hyal-1 and -2 contribute to intracellular and extracellular catabolism of HA, respectively, in a CD44-dependent manner, and their HA degradation occurs independently from one another.
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PMID:CD44-dependent intracellular and extracellular catabolism of hyaluronic acid by hyaluronidase-1 and -2. 1717 Jan 10

We present here a novel synthesis route to functionalize high molecular weight hyaluronan (HMW-HA) with a hydrazide group and a bioactive ligand, namely bisphosphonate (BP). For this purpose, a new symmetrical self-immolative biscarbazate linker has been devised. The hydrazide group was used to form hydrazone cross-linked hydrogel upon treating with previously described aldehyde modified hyaluronan. The 1:1 weight ratio of these two polymers gave hydrogel in less than 30 s. In this communication we present the first in vitro results showing that even though HA can target CD44 positive cancer cells (HCT-116), receptor mediated endocytosis could only occur by cleavage of high molecular weight HA with an ubiquitous enzyme, hyaluronidase (Hase). The cancer cells are known to overexpress CD44 receptors and also increase the hyaluronidase activity in vivo. Thus the pro-drug design, based on drug conjugation to HMW-HA, represents a new drug delivery platform where the drug potency is triggered by Hase mediated degradation of the HA-drug conjugate. We have successfully demonstrated that the cross-linkable HA-BP conjugate first undergoes Hase-mediated scission to the fragments of suitable sizes so as to be internalized by CD44 positive cells. The specificity of this targeting was proven by comparing the results with less CD44 positive HEK-293T cells. The localized delivery of such drugs at the surgical resection site opens up avenues to control tumor recurrence after removal of the tumor. In the form of hydrogel it would prevent systemic exposure of the drug and would allow its controlled release.
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PMID:In situ cross-linkable high molecular weight hyaluronan-bisphosphonate conjugate for localized delivery and cell-specific targeting: a hydrogel linked prodrug approach. 1949 15