Polyclonal and Monoclonal Antibodies Specific for USP17, a Proapoptotic Deubiquitinating Enzyme

Expression and functional implications of USP17 in glioma

Glioma is the most common and malignant brain tumor with extremely poor prognosis. It is crucial to understand the molecular characteristics of glioma and find out more effective therapeutic targets for the treatment of glioma. USP17 is a novel deubiquitinating enzyme that is differentially expressed in certain types of solid tumor. Our present study investigated the pathological functions and clinical significance of USP17 in glioma for the first time. We found that USP17 was down-regulated in glioma tissue compared with normal tissues. Overexpression of USP17 in glioma cells reduced their tumorigenesis and proliferation ability through reducing Ras and Myc protein levels. Subsequent in vivo experiments showed that overexpression of USP17 suppressed tumor progression in an orthotopic glioma models. Further, study of a cohort of 104 patients with stage I-IV glioma showed that USP17 expression was negatively associated with the WHO grade (p<0.001). USP17 was more highly expressed in low grade (I+II) glioma than high-grade (III+IV) glioma (p<0.001). Taken together, our results indicate that USP17 might play important functions in glioma through suppressing glioma tumorigenesis and proliferation.

Biological functions of hyaluronan and cytokine-inducible deubiquitinating enzymes

The modification of proteins through post-translation and degradation by the ubiquitin-proteasome system plays a pivotal role in a broad array of biological processes. Reversal of this process by deubiquitination is a central step in the maintenance and regulation of cellular homeostasis. It now appears that the regulation of ubiquitin pathways by deubiquitinating enzymes (DUBs) could be used as targets for anticancer therapy. Recent success in inducing apoptosis in cancerous cells by USP17, a cytokine-inducible DUB encoding two hyaluronan binding motifs (HABMs) showing direct interaction with hyaluronan (HA), could prove a promising step in the development of DUBs containing HABMs as agents in anticancer therapeutics. In this review, we summarize the importance of hyaluronan (HA) in cancer, the role played by DUBs in apoptosis, and a possible relationship between DUBs and HA in cancerous cells, suggesting new strategies for applying DUB enzymes as potential anticancer therapeutics.

Polyclonal and monoclonal antibodies specific for ubiquitin-specific protease 20

Ubiquitination and deubiquitination are important processes for numerous intracellular mechanisms, and the imbalance of these two processes can cause severe diseases including cancer. Accordingly, deubiquitinating enzymes (DUBs) responsible for deubiquitination from their protein substrates become attractive targets for many studies. USP20, also known as VDU2, belongs to ubiquitin-specific protease (USP) subfamily of DUBs and has several important roles in cells as shown with other DUBs. USP20 stabilizes HIF-1α by abolishing von Hippel-Lindau protein (pVHL)-E3 ligase complex-mediated HIF-1α degradation. USP20 is also associated with β2 adrenergic receptor recycling. In addition, a previous study demonstrated that USP20 regulates Tax-induced NF-κB activation through its deubiquitinating activity. These studies provide a line of evidence that USP20 has critical roles in cellular functions. In this study, we generated and characterized a polyclonal and two monoclonal antibodies against USP20. It is feasible that USP20 antibodies can be useful to investigate USP20-related cellular mechanisms and to find novel substrates of USP20.