Comprehensive analysis of the role of ubiquitin-specific peptidases in colorectal cancer:A systematic review

BACKGROUND Colorectal cancer(CRC)is the third most frequent and the second most fatal cancer.The search for more effective drugs to treat this disease is ongoing.A better understanding of the mechanisms of CRC development and progression may reveal new therapeutic strategies.Ubiquitin-specific peptidases(USPs),the largest group of the deubiquitinase protein family,have long been implicated in various cancers.There have been numerous studies on the role of USPs in CRC;however,a comprehensive view of this role is lacking.AIM To provide a systematic review of the studies investigating the roles and functions of USPs in CRC.METHODS We systematically queried the MEDLINE(via PubMed),Scopus,and Web of Science databases.RESULTS Our study highlights the pivotal role of various USPs in several processes implicated in CRC:Regulation of the cell cycle,apoptosis,cancer stemness,epithelial–mesenchymal transition,metastasis,DNA repair,and drug resistance.The findings of this study suggest that USPs have great potential as drug targets and noninvasive biomarkers in CRC.The dysregulation of USPs in CRC contributes to drug resistance through multiple mechanisms.CONCLUSION Targeting specific USPs involved in drug resistance pathways could provide a novel therapeutic strategy for overcoming resistance to current treatment regimens in CRC.

Inhibition of Ubiquitin-specific Peptidase 8 Suppresses Adrenocorticotropic Hormone Production and Tumorous Corticotroph Cell Growth in AtT20 Cells

Background： Two recent whole-exome sequencing researches identifying somatic mutations in the ubiquitin-specific protease 8 （USP8） gene in pituitary corticotroph adenomas provide exciting advances in this field. These mutations drive increased epidermal growth factor receptor （EGFR） signaling and promote adrenocorticotropic hormone （ACTH） production. This study was to investigate whether the inhibition of USP8 activity could be a strategy/br the treatment of Cushing＇s disease （CD）. Methods： The anticancer effect of USP8 inhibitor was determined by testing cell viability, colony tbrmation, apoptosis, and ACTH secretion. The immunoblotting and quantitative reverse transcription polymerase chain reaction were conducted to explore the signaling pathway by USP8 inhibition. Results： Inhibition of USP8-induced degradation of receptor tyrosine kinases including EGFR, EGFR-2 （ERBB2）, and Met leading to a suppression of ArT20 cell growth and ACTH secretion. Moreover, treatment with USP8 inhibitor markedly induced AtT20 cells apoptosis. Conclusions： Inhibition of USP8 activity could be an effective strategy for CD. It might provide a novel pharmacological approach for the treatment of CD.

Ubiquitin-specific protease 21 promotes tumorigenicity and stemness of colorectal cancer by deubiquitinating and stabilizing ZEB1

BACKGROUND Colorectal cancer(CRC)is one very usual tumor together with higher death rate.Ubiquitin-specific protease 21(USP21)has been confirmed to take part into the regulation of CRC progression through serving as a facilitator.Interestingly,the promotive function of USP21 has also discovered in the progression of CRC.ZEB1 has illustrated to be modulated by USP7,USP22 and USP51 in cancers.However,the regulatory functions of USP21 on ZEB1 in CRC progression need more invest-igations.AIM To investigate the relationship between USP21 and ZEB1 in CRC progression.METHODS The mRNA and protein expressions were assessed through RT-qPCR,western blot and IHC assay.The interaction between USP21 and ZEB1 was evaluated through Co-IP and GST pull down assays.The cell proliferation was detected through colony formation assay.The cell migration and invasion abilities were determined through Transwell assay.The stemness was tested through sphere formation assay.The tumor growth was evaluated through in vivo mice assay.RESULTS In this work,USP21 and ZEB1 exhibited higher expression in CRC,and resulted into poor prognosis.Moreover,the interaction between USP21 and ZEB1 was further investigated.It was demonstrated that USP21 contributed to the stability of ZEB1 through modulating ubiquitination level.In addition,USP21 streng-thened cell proliferation,migration and stemness through regulating ZEB1.At last,through in vivo assays,it was illustrated that USP21/ZEB1 axis aggravated tumor growth.CONCLUSION For the first time,these above findings manifested that USP21 promoted tumorigenicity and stemness of CRC by deubiquitinating and stabilizing ZEB1.This discovery suggested that USP21/ZEB1 axis may provide novel sights for the treatment of CRC.

Dipeptidyl peptidase Ⅲ在先天性白内障大鼠晶状体中的免疫活性变化

目的 观察 8、10、12、14周龄正常及先天性白内障大鼠晶状体中dipeptidylpep tidaseⅢ (DPPⅢ )的免疫活性变化 ,探讨其与白内障发病的关系。方法 分别于 8、10、12、14周龄鼠 ,摘取正常对照组以及先天性白内障大鼠晶状体 ,应用抗生物素蛋白 生物素 过氧化物酶复合体法 ,观察不同时期大鼠晶状体中DPPⅢ的免疫活性变化。结果 各周龄先天性白内障大鼠晶状体纤维部DPPⅢ的免疫活性明显高于正常对照组 ,特别是 12、14周白内障晶状体中DPPⅢ的免疫阳性产物扩展至晶状体核周部。结论 DPPⅢ在白内障大鼠晶状体中免疫活性增强 ,它有可能在白内障形成过程中参与晶状体蛋白的水解分化 ,从而促进白内障的形成。

Novel mutations in ubiquitin-specific protease 26 gene might cause spermatogenesis impairment and male infertility

Aim： To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 （USP26） gene and its involvement in idiopathic male infertility in China. Methods： Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls. Results： Of 41 infertile men, 9 （22.0%, P = 0.01） had changes in USP26 gene on the X chromosome. A compound mutation （364insACA; 460G→A） was detected in 8 patients （19.5%, P = 0.01） and a 1044T→A substitution was found in 1 patient （2.4%, P 〉 0.05）. All three variations led to changes in the coding amino acids. Two substitutions predict some changes： 460G→ A changes a valine into an isoleucine, and 1044T → A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls. Conclusion： The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress.

Anti-diabetic potential of Urena lobata leaf extract through inhibition of dipeptidyl peptidase IV activity

Objective: To evaluate the anti-diabetic potential of leaf extract from Urena lobata(U. lobata) through dipeptidyl peptidase IV(DPP-IV) inhibitory activity.Methods: U. lobata leaf was extracted in hot water and ethanol. The activity of DPPIV inhibitor was tested by in vitro study using gly-pro-p-nitroanilide as substrat of DPPIV and vildagliptin, as standard reference. A product of the reactions between gly-pro-pnitroanilide and DPP-IV, was observed by microplate readers with λ = 405 nm. All data were expressed as mean ± SD and the IC50 value was determined by non linear regression curve fit. Active substances in leaf extract of U. lobata was analyzed by liquid chromatography-mass spectrometry. DPP-IV inhibitory activity of active compounds was evaluated in silico using docking server. Results: The ethanolic extract of U. lobata showed stronger DPP-IV inhibitor activity than water extract with the IC50 values of 1 654.64 and 6 489.88 μg/mL, respectively. Vildagliptin, based on standard reference for DPP-IV inhibitor activity, has IC50 value of 57.44 μg/mL. Based on in silico analysis, mangiferin, stigmasterol and β-sitosterol in U. lobata extract have a strong inhibitory activity on DPP-IV. Conclusions: The results showed that DPP-IV inhibitory activity of U. lobata is related to its active compounds such as mangiferin, stigmasterol and β-sitosterol.

Dipeptidyl peptidase Ⅳ(DPP Ⅳ):a novel emerging target for thetreatment of type 2 diabetes

The enzyme, dipeptidyl peptidase IV（DPP IV）, is a novel target for the treatment of type 2 diabetes. Dipeptidyl peptidase IV inhibition improves the impaired insulin secretion and decrease postprandial concentrations of glucagon by enhancing the incretin hormone levels lucagon-like peptide-1（GLP-1） and glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide（GIP）. Recently, DPP IV inhibitors have attracted more and more attention, several of which have entered pre-clinical and clinical trials, and one has received approval for use as an anti-diabetic agent. Among the DPP IV inhibitors, two leading agents（sitagliptin and vildagliptin） have been shown to be effective in reducing glycosylated hemoglobin（HbAlc） and fasting plasma glucose（FPG） in patients with type 2 diabetes. This review summarizes the evidence supporting DPP IV inhibitors as potential antidiabetic agents.

Ubiquitin-specific protease 22 enhances intestinal cell proliferation and tissue regeneration after intestinal ischemia reperfusion injury

BACKGROUND Intestinal ischemia reperfusion(I/R) injury is a serious but common pathophysiological process of many diseases, resulting in a high mortality rate in clinical practice. Ubiquitin-specific protease 22(USP22) acts as regulator of cell cycle progression, proliferation, and tumor invasion. Depleted USP22 expression has been reported to contribute to arrested cell cycle and disrupted generation of differentiated cell types in crypts and villi. However, the role of USP22 in intestinal damage recovery has not been investigated. Therefore, elucidation of the underlying mechanism of USP22 in intestinal I/R injury may help to improve the tissue repair and patient prognosis in clinical practice.AIM To investigate the role of USP22 in intestinal cell proliferation and regeneration after intestinal I/R injury.METHODS An animal model of intestinal I/R injury was generated in male Sprague-Dawley rats by occlusion of the superior mesenteric artery followed by reperfusion.Chiu's scoring system was used to grade the damage to the intestinal mucosa. An in vitro model was developed by incubating rat intestinal epithelial IEC-6 cells in hypoxia/reoxygenation conditions in order to simulate I/R in vivo. siRNA and overexpression plasmid were used to regulate the expression of USP22. USP22,Cyclin D1, and proliferating cell nuclear antigen(PCNA) expression levels were measured by Western blot analysis and immunohistochemistry staining. Cell survival(viability) and cell cycle were evaluated using the Cell Counting Kit-8and flow cytometry, respectively.RESULTS USP22 expression was positively correlated with the expression levels of PCNA and Cyclin D1 both in vivo and in vitro, which confirmed that USP22 was involved in cell proliferation and intestinal regeneration after intestinal I/R injury. Decreased levels of Cyclin D1 and cell cycle arrest were observed in the USP22 knockdown group(P < 0.05), while opposite results were observed in the USP22 overexpression group(P < 0.05). In addition, increased expression of USP22 was related to improved intestinal pathology or IEC-6 cell viability after I/R or hypoxia/reoxygenation. These results suggested that USP22 may exert a protective effect on intestinal I/R injury by regulating cell proliferation and facilitating tissue regeneration.CONCLUSION USP22 is correlated with promoting intestinal cell proliferation and accelerating intestinal tissue regeneration after intestinal I/R injury and may serve as a potential target for therapeutic development for tissue repair during intestinal I/R injury.

Regulation of dipeptidyl peptidase 8 and 9 expression in activated lymphocytes and injured liver

AIM:To investigate the expression of dipeptidyl peptidase(DPP) 8 and DPP9 in lymphocytes and various models of liver fibrosis.METHODS:DPP8 and DPP9 expression were measured in mouse splenic CD4 + T-cells,CD8 + T-cells and B-cells(B220 +),human lymphoma cell lines and mouse splenocytes stimulated with pokeweed mitogen(PWM) or lipopolysaccharide(LPS),and in dithiothreitol(DTT) and mitomycin-C treated Raji cells.DPP8 and DPP9 expression were measured in epidermal growth factor(EGF) treated Huh7 hepatoma cells,in fibrotic liver samples from mice treated with carbon tetrachloride(CCl 4) and from multidrug resistance gene 2(Mdr2 /Abcb4) gene knockout(gko) mice with biliary fibrosis,and in human end stage primary biliary cirrhosis(PBC).RESULTS:All three lymphocyte subsets expressed DPP8 and DPP9 mRNA.DPP8 and DPP9 expression were upregulated in both PWM and LPS stimulated mouse splenocytes and in both Jurkat T-and Raji B-cell lines.DPP8 and DPP9 were downregulated in DTT treated and upregulated in mitomycin-C treated Raji cells.DPP9transfected Raji cells exhibited more annexin V + cells and associated apoptosis.DPP8 and DPP9 mRNA were upregulated in CCl 4 induced fibrotic livers but not in the lymphocytes isolated from such livers,while DPP9 was upregulated in EGF stimulated Huh7 cells.In contrast,intrahepatic DPP8 and DPP9 mRNA expression levels were low in the Mdr2 gko mouse and in human PBC compared to non-diseased livers.CONCLUSION:These expression patterns point to biological roles for DPP8 and DPP9 in lymphocyte activation and apoptosis and in hepatocytes during liver disease pathogenesis.

The role of peptidase neurolysin in neuroprotection and neural repair after stroke

Current experimental stroke research has evolved to focus on detailed understanding of the brain’s self-protective and restorative mechanisms,and harness this knowledge for development of new therapies.In this context,the role of peptidases and neuropeptides is of growing interest.In this focused review,peptidase neurolysin(Nln)and its extracellular peptide substrates are briefly discussed in relation to pathophysiology of ischemic stroke.Upregulation of Nln following stroke is viewed as a compensatory cerebroprotective mechanism in the acute phase of stroke,because the main neuropeptides inactivated by Nln are neuro/cerebrotoxic(bradykinin,substance P,neurotensin,angiotensin II,hemopressin),whereas the peptides generated by Nln are neuro/cerebroprotective(angiotensin-(1–7),Leu-/Met-enkephalins).This notion is confirmed by experimental studies documenting aggravation of stroke outcomes in mice after inhibition of Nln following stroke,and dramatic improvement of stroke outcomes in mice overexpressing Nln in the brain.The role of Nln in the(sub)chronic phase of stroke is less clear and it is likely,that this peptidase does not have a major role in neural repair mechanisms.This is because,the substrates of Nln are less uniform in modulating neurorestorative mechanisms in one direction,some appearing to have neural repair enhancing/stimulating potential,whereas others doing the opposite.Future studies focusing on the role of Nln in pathophysiology of stroke should determine its potential as a cerebroprotective target for stroke therapy,because its unique ability to modulate multiple neuropeptide systems critically involved in brain injury mechanisms is likely advantageous over modulation of one pathogenic pathway for stroke pharmacotherapy.

Association of 370-371insACA, 494T〉C, and 1423C〉T haplotype in ubiquitin-specific protease 26 gene and male infertility： a meta-analysis

Whether the 370-371insACA, 494T〉C, and 1423C〉T haplotype in ubiquitin-specific protease 26 （USP26） gene is associated with male infertility is controversial. To clarify this issue, we conducted a meta-analysis based on the most recent studies. Eligible studies were screened by using PubMed and Embase. Pooled odd ratio （OR） with 95% confidence interval （CI） was calculated with fixed effect models. Ten studies with 1603 patients and 2505 controls were included, Overall, the results indicated that there was an association between the haplotype and male infertile risk （OR = 1.74, 95% CI： 1.09-2.77）. The OR calculated based on the five studies in Asia and three in Europe was 1.96 （95% CI： 1,05-3.67） and 1.54 （95% Ch 0.75-3.16） respectively, however, the OR was 0.86 （95% Ch 0.05-15,29） based on the two investigations in America. In addition, the data from the patients with azoospermia （AZO） showed an increased pooled OR of 2.35 （95% Cl： 1.22-4.50）. In contrast, the studies with oligoasthenoteratozoospermia （OAT） exhibited that the pooled OR was 0,97 （95% Ch 0.43-2.16）. Our analyses indicate that there is an association of alteration in USP26 with male infertility, especially in AZO and Asian population.

Ubiquitin-specific protease 15 contributes to gastric cancer progression by regulating the Wnt/β-catenin signaling pathway

BACKGROUND Ubiquitin-specific protease 15(USP15)is an important member of the ubiquitinspecific protease family,the largest deubiquitinase subfamily,whose expression is dysregulated in many types of cancer.However,the biological function and the underlying mechanisms of USP15 in gastric cancer(GC)progression have not been elucidated.AIM To explore the biological role and underlying mechanisms of USP15 in GC progression.METHODS Bioinformatics databases and western blot analysis were utilized to determine the expression of USP15 in GC.Immunohistochemistry was performed to evaluate the correlation between USP15 expression and clinicopathological characteristics of patients with GC.A loss-and gain-of-function experiment was used to investigate the biological effects of USP15 on GC carcinogenesis.RNA sequencing,immunofluorescence,and western blotting were performed to explore the potential mechanism by which USP15 exerts its oncogenic functions.RESULTS USP15 was up-regulated in GC tissue and cell lines.The expression level of USP15 was positively correlated with clinical characteristics(tumor size,depth of invasion,lymph node involvement,tumor-node-metastasis stage,perineural invasion,and vascular invasion),and was related to poor prognosis.USP15 knockdown significantly inhibited cell proliferation,invasion and epithelialmesenchymal transition(EMT)of GC in vitro,while overexpression of USP15 promoted these processes.Knockdown of USP15 inhibited tumor growth in vivo.Mechanistically,RNA sequencing analysis showed that USP15 regulated the Wnt signaling pathway in GC.Western blotting confirmed that USP15 silencing led to significant down-regulation ofβ-catenin and Wnt/β-catenin downstream genes(c-myc and cyclin D1),while overexpression of USP15 yielded an opposite result and USP15 mutation had no change.Immunofluorescence indicated that USP15 promoted nuclear translocation ofβ-catenin,suggesting activation of the Wnt/β-catenin signaling pathway,which may be the critical mechanism promoting GC progression.Finally,rescue experiments showed that the effect of USP15 on gastric cancer progression was dependent on Wnt/β-catenin pathway.CONCLUSION USP15 promotes cell proliferation,invasion and EMT progression of GC via regulating the Wnt/β-catenin pathway,which suggests that USP15 is a novel potential therapeutic target for GC.

Development and evaluation of an ELISA method for the measurement of kallikrein-related peptidase 5 (KLK5) in human serum

Kallikrein-related peptidases (KLKs) have been proposed as potential cancer biomarkers. Kallikrein-related peptidase 5 (KLK5) is a secreted trypsin-like protease of the KLKs. Until now, detection of KLK5 in both biological fluids and tissues has been described frequently due to the potential of being a new cancer biomarker. Our objective was to prepare KLK5 antibodies and establish an ELISA method for KLK5 to study the possible clinical application of KLK5 as a biomarker for malignancies. In this study, recombinant KLK5 protein was produced and purified using a prokaryotic expression system, and then used as immunogen to generate antibodies. High titers of specific antibodies were measured in serum of rabbits after the forth booster injection. And the titer of the antiserum reached 1:106. We have also generated monoclonal antibodies using hybridoma technology and the titer reached 1:105. The activity of KLK5 antibodies was characterized by Western blot and immunohistochemistry. To quantitatively examine KLK5 in serum samples, we established double antibody sandwich ELISA method using mouse mAb as capture and rabbit pAb as tracer antibody. We have detected KLK5 levels in ovarian cancer serum to ensure that our sandwich ELISA measurement to have high sensitivity and specificity. The ranges of linearity reached by the standard curves of the newly developed ELISA were 0.45 ng/mL to 125 ng/mL. The detection limit of the method, defined as the concentration of KLK5 can be distinguished, was 0.20 ng/mL. Median serum KLK5 levels were 3.77 ng/mL and 0.86 ng/mL in ovarian cancer patients and normal female, respectively (P ELISA assay for KLK5. Our preliminary findings prompt that KLK5 may be a new potential biomarker for the diagnosis and prognosis in patients with ovarian.

Role of dipeptidyl peptidase 4 inhibitors in the new era of antidiabetic treatment

The last few years important changes have occurred in the field of diabetes treatment.The priority in the therapy of patients with diabetes is not glycemic control per se rather an overall management of risk factors,while individualization of glycemic target is suggested.Furthermore,regulatory authorities now require evidence of cardiovascular(CV)safety in order to approve new antidiabetic agents.The most novel drug classes,i.e.,sodium-glucose transporter 2 inhibitors(SGLT2-i)and some glucagon-like peptide-1 receptor agonists(GLP-1 RA),have been demonstrated to reduce major adverse CV events and,thus,have a prominent position in the therapeutic algorithm of hyperglycemia.In this context,the role of previously used hypoglycemic agents,including dipeptidyl peptidase 4(DPP-4)inhibitors,has been modified.DPP-4 inhibitors have a favorable safety profile,do not cause hypoglycemia or weight gain and do not require dose uptitration.Furthermore,they can be administered in patients with chronic kidney disease after dose modification and elderly patients with diabetes.Still,though,they have been undermined to a third line therapeutic choice as they have not been shown to reduce CV events as is the case with SGLT2-i and GLP-1 RA.Overall,DPP-4 inhibitors appear to have a place in the management of patients with diabetes as a safe class of oral glucose lowering agents with great experience in their use.

Neonatal Exposure to the Dipeptidyl Peptidase-IV Inhibitors Diprotin A and Sitagliptin Induces Depression-Like Behavior, Anxiety, and Latent Aggression in Adolescent and Adult Rats

Emotional and motivational disorders in adults are often considered to be the result of altered neurodevelopment. Clinical and experimental data provide evidence that serine protease dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) is involved in the pathophysiology of psycho-emotional disorders. Recently, we have shown that adolescent and adult rats exhibit an increase in anxiety and depression-related behaviors after neonatal administration of a synthetic non-competitive inhibitor of DPP-IV, methionyl-2(S)-cyano-pyrrolidine. In the present study, we tested the effects of two competitive, selective DPP-IV inhibitors, sitagliptin (4 mg/kg) and diprotin A (2 mg/kg), administered at postnatal days 5 - 18 on the emotional and motivational behavior of adolescent and adult rats. We observed increased anxiety in one-month-old diprotin A- or sitagliptin-treated rats in the elevated plus maze;diprotin A also enhanced the animals’ anxiety score using a ranked scale for evaluating anxiety and phobias. In the sucrose consumption and preference test, depressive-like behavior was pronounced in both the diprotin A- and sitagliptin-treated one-month-old animals, while only the diprotin A-treated rats exhibited a decrease in sucrose consumption at the age of 2 months. The diprotin A-treated rats also demonstrated behavioral despair and decreased activity in the forced swimming test within 1 - 3 months of age. Increased aggression was observed in 1 - 3-month-old diprotin A-treated rats and in two-month-old sitagliptin-treated rats. These findings support the hypothesis that DPP-IV is involved in the genesis of emotional and motivational disorders. Additionally, the results show that diprotin А impairs the adolescent and adult rats’ behavior more significantly than sitagliptin when the animals were treated with the DPP-IV inhibitors in the early postnatal period.

Identification and dipeptidyl peptidase Ⅳ(DPP-Ⅳ) inhibitory activity verification of peptides from mouse lymphocytes

The objective of this study was to isolate and identify the intracellular bioactive peptides from mouse lymphocytes before and after lipopolysaccharide(LPS)stimulation,to explore novel peptides and to research the bioactive function.Mouse spleen lymphocytes were isolated and cultured with LPS stimulation(experimental group)or not(control group)to collect intracellular peptides.Totally 385 peptides were analyzed by nanoliter liquid phase-Q Exactive quadrupole ultra-high resolution orbitrap mass spectrometer(Nano LC-Q Exactive Plus)and identifi ed by PEAKS X software.After compared with peptides reported,131 novel peptides were discovered,which then were predicted bioactivity by Peptide Ranker and 6 peptides with high bioactivity were predicted function by BIOPEP-UMW database.Prediction data showed that they may have dipeptidyl peptidase IV(DPP-IV)inhibitory activity.Finally,two peptides showed better potent inhibition were verifi ed with competitive and noncompetitive modes.

Effect of vitamin E and human placenta cysteine peptidase inhibitor on expression of cathepsins B and L in implanted hepatoma Morris 5123 tumor model in Wistar rats

AIM: To examine the effectiveness of human placental inhibitors, by injecting vitamin E to rats with transplanted Morris-5123 hepatoma, on the expression of cathepsins B and L in tumor, liver, lung and blood sera after transplantation of Morris 5123 hepatoma. METHODS: Animals were divided into 10 groups receiving three different concentrations of vitamin E and inhibitors along or in combination and compared with negative control (healthy rats) and positive control (tumor rats). Effectiveness of treatment was evaluated with regard to survival time, tumor response and determination of the activities of proteolytic enzymes and their inhibitors using flurogenic substrates. RESULTS: Cathepsins B and L activities were elevated by 16-fold in comparison with negative control tissues, and their endogenous inhibitor activity decreased by 1.2-fold before treatment. In several cases, tumors completely disappeared following vitamin E plus human placental cyteine protease inhibitor (CPI) compared with controls. The number of complete tumor responses was higher when 20 m/kg vitamin E plus 400 μg of CPI was used, i.e. 7/10 rats survived more than two mo. Cathepsins B and L were expressed significantly in tumor, liver, lung tissues and sera in parallel to the increasing of the endogenous inhibitor activity compared with the controls after treatment(P<0.0001) CONCLUSION: The data indicate formation of metastasis significantly reduced in treated rats, which might provide a therapeutic basis for anti-cancer therapy.

Cysteine peptidase and its inhibitor activity levels and vitamin E concentration in normal human serum and colorectal carcinomas

AIM: Cysteine peptidase (CP) and its inhibitor (CPI) are a matrix protease that may be associated with colorectal carcinoma invasion and progression, and vitamin E is also a stimulator of the immunological system. Our purpose was to determine the correlation between the expression of cysteine peptidases and their endogenous inhibitors,and the level of vitamin E in sera of patients with colorectal cancer in comparison with healthy individuals.METHODS: The levels of cysteine peptidases and their inhibitors were determined in the sera of patients with primary and metastatic colorectal carcinoma and healthy individuals using fluorogenic substrate, and the level of vitamin E was determined by HPLC.RESULTS: The levels of cysteine peptidases and their inhibitors were significantly higher in the metastatic colorectal cancer patients than that in the healthy controls (P＜0.05).The activity of CP increased 2.2-fold, CPI 2.8-fold and vitamin E decreased 3.4-fold in sera of patients with metastasis in comparison with controls. The level of vitamin E in healthy individuals was higher, whereas the activity of cysteine peptidases and their inhibitors associated with complexes was lower than that in patients with cancer of the digestive tract.CONCLUSION: These results suggest that the serum levels of CP and their inhibitors could be an indicator of the prognosis for patients with metastatic colorectal cancer. Vitamin E can be administered prophylactically to prevent digestive tract neoplasmas.

Dipeptidyl peptidase-4 inhibitor for steroid-induced diabetes

The addition of the dipeptidyl peptidase-4 (DDP-4) inhibitor has been reported to achieve greater improvements in glucose metabolism with fewer adverse events compared to increasing the metformin dose in type 2 diabetic patients. We present a patient with steroid-induced diabetes whose blood glucose levels were ameliorated by the use of the DPP-4 inhibitor, showing that the DPP-4 inhibitors may be an effective and safe oral anti-diabetic drug for steroid-induced diabetes.

Emerging potential of ubiquitin-specific proteases and ubiquitinspecific proteases inhibitors in breast cancer treatment

Breast cancer is the most frequently diagnosed cancer in women,accounting for 30%of new diagnosing female cancers.Emerging evidence suggests that ubiquitin and ubiquitination played a role in a number of breast cancer etiology and progression processes.As the primary deubiquitinases in the family,ubiquitin-specific peptidases(USPs)are thought to represent potential therapeutic targets.The role of ubiquitin and ubiquitination in breast cancer,as well as the classification and involvement of USPs are discussed in this review,such as USP1,USP4,USP7,USP9X,USP14,USP18,USP20,USP22,USP25,USP37,and USP39.The reported USPs inhibitors investigated in breast cancer were also summarized,along with the signaling pathways involved in the investigation and its study phase.Despite no USP inhibitor has yet been approved for clinical use,the biological efficacy indicated their potential in breast cancer treatment.With the improvements in phenotypic discovery,we will know more about USPs and USPs inhibitors,developing more potent and selective clinical candidates for breast cancer.