Targeting ubiquitin specific protease 7 in cancer: A deubiquitinase with great prospects.

Deubiquitinase (DUB)-mediated cleavage of ubiquitin chain balances ubiquitination and deubiquitination for determining protein fate. USP7 is one of the best characterized DUBs and functionally important. Numerous proteins have been identified as potential substrates and binding partners of USP7; those play crucial roles in diverse array of cellular and biological processes including tumour suppression, cell cycle, DNA repair, chromatin remodelling, and epigenetic regulation. This review aims at summarizing the current knowledge of this wide association of USP7 with many cellular processes that enlightens the possibility of abnormal USP7 activity in promoting oncogenesis and the importance of identification of specific inhibitors.

[Safety and effectiveness of GreenLight 120-W laser photoselective vaporization of the prostate for benign prostatic hyperplasia: A meta-analysis].

OBJECTIVE: To evaluate the safety and effectiveness of GreenLight 120-W laser photoselective vaporization of the prostate (PVP) versus transurethral resection of the prostate (TURP) for benign prostatic hyperplasia (BPH). METHODS: We searched PubMed, Medline, Embase, Cochrane Library, Wanfang, CNKI, and VIP for randomized control trials and their references addressing 120-W PVP versus TURP in the treatment of BPH. Based on the inclusion and exclusion criteria, two reviewers independently accomplished the screening, quality assessment, and data extraction of the identified studies and performed meta-analyses using RevMan 5.2. RESULTS: Totally, 6 randomized control trials were included in this analysis, involving 703 cases, 351 treated by PVP and 352 by TURP. Compared with TURP, PVP showed significantly decreased time of catheterization (by 32. 55 hours, 95% CI 15.3 -49.8, P < 0.01), hospital stay (by 1.85 days, 95% CI 1.2-2.5, P < 0.01), and intraoperative blood loss (by 15.6 g/L, 95% CI 10.0-21.2, P < 0.01), but increased time of operation (by 9.37 minutes, 95% CI 5. 1-13.6, P < 0.01). There was also a significant reduction in blood transfusion, TUR syndrome, and capsular perforation in the PVP group. At 12 months after surgery, no statistically significant differences were found between the two groups in the improvement of maximum urinary flow rate, IPSS, postvoid residual, and sexual function. CONCLUSION: GreenLight 120-W laser PVP is a safe and effective procedure for the treatment of BPH, with similar effectiveness to TURP but less blood loss, shorter time of catheterization and hospital stay, and lower incidences of blood transfusion, TUR syndrome and capsular perforation.

Ubiquitin-proteasome pathway and prostate cancer.

Prostate cancer is one of the most common cancers in men. Various signaling pathways and proteins are involved in prostate carcinogenesis. Ubiquitination and deubiquitination of the related proteins contribute to the development of prostate cancer in various ways. The ubiquitin-proteasome (UPS) system is a common cellular process for protein degradation in eukaryotes. In this article we review recent advances related to the involvement of the UPS pathway in prostate cancer. The UPS pathway plays an important role in the regulation of cellular proteins with respect to cell cycle control, transcription, apoptosis, cell adhesion, angiogenesis, and tumor growth. It is involved in prostate cancer in various ways by modulating prostate cancer-related genes/proteins such as androgen receptor, cyclin-dependent kinase inhibitor P27, cyclin D1, and PTEN. Some ubiquitin-like modifier proteins have also been found to be associated with prostate cancer. The UPS pathway represents a potential therapeutic target for prostate cancer, and proteasome inhibitors represent a class of chemotherapeutic agents that inhibit tumor growth. The UPS pathway is related to prostate cancer in different ways. More research on that link is needed, as targeting the UPS pathway has led to some success in prostate cancer treatment.

Postpolypectomy syndrome without abdominal pain led to sepsis/septic shock and gastrointestinal bleeding: A case report.

BACKGROUND: Postpolypectomy syndrome (PPS) is a rare postoperative complication of colonic polypectomy. It presents with abdominal pain and fever accompanied by coagulopathy and elevated inflammatory markers. Its prognosis is usually good, and it only requires outpatient treatment or observation in a general ward. However, it can be life-threatening. CASE SUMMARY: The patient was a 58-year-old man who underwent two colonic polypectomies, each resulting in life-threatening sepsis, septic shock, and coagulopathy. Each of the notable manifestations was a rapid drop in blood pressure, an increase in heart rate, loss of consciousness, and heavy sweating, accompanied by shortness of breath and decreased oxygen in the finger pulse. Based on the criteria of organ dysfunction due to infection, we diagnosed him with sepsis. The patient also experienced severe gastrointestinal bleeding after the second operation. Curiously, he did not complain of any abdominal pain throughout the course of the illness. He had significantly elevated concentrations of inflammatory markers and coagulopathy. Except for the absence of abdominal pain, his fever, significant coagulopathy, and elevated inflammatory marker concentrations were all consistent with PPS. Abdominal computed tomography and superior mesenteric artery computed tomography angiography showed no free air or vascular damage. Thus, the diagnosis of colon perforation was not considered. The final blood culture results indicated Moraxella osloensis. The patient was transferred to the intensive care unit and quickly improved after fluid resuscitation, antibiotic treatment, oxygen therapy, and blood transfusion. CONCLUSION: PPS may induce dysregulation of the systemic inflammatory response, which can lead to sepsis or septic shock, even in the absence of abdominal pain.

Knockdown of USP8 inhibits prostate cancer cell growth, proliferation, and metastasis and promotes docetaxel's activity by suppressing the NF-kB signaling pathway.

Ubiquitin-specific protease 8 (USP8) has been recently reported to be involved in tumorigenesis. Prostate cancer (PCa) is the most diagnosed malignancy among men, but USP8's role in PCa is not yet investigated comprehensively. Therefore, the PCa cell lines DU145 and PC3 were transfected with USP8 siRNA or overexpressing vector together with or without docetaxel. The silencing USP8 and docetaxel treatment reduced cell viability and migration and promoted apoptosis. In contrast, USP8 knockdown was found to enhance docetaxel antitumor activity. In contrast, increased cell viability and migration were noticed upon USP8 overexpression, thereby decreasing apoptosis and suppressing docetaxel antitumor activity. Notably, although EGFR, PI3K, and NF-kB were found to be increased in both USP8 overexpression and docetaxel treatment, it significantly attenuated the effects in USP8 silencing followed by with or without docetaxel. Although EGFR silencing decreased PI3K and NF-kB activation, overexpression of USP8 was shown to counteract SiEGFR's effects on NF-kB signaling by increasing PI3K expression. Our findings revealed that USP8 plays an oncogenic role in PCa and can suppress docetaxel activity. Additionally, as EGFR/PI3K/NF-kB was previously reported to develop docetaxel resistance, the combination treatment of USP8 knockdown with docetaxel might be a potential PCa therapeutic.

Genetic polymorphisms of metabolic enzymes-CYP1A1, CYP2D6, GSTM1, and GSTT1, and gastric carcinoma susceptibility.

Genetic polymorphisms in metabolic enzymes are associated with numerous cancers. In this study, the relationships between genetic polymorphisms of phase I metabolic enzymes including cytochrome P450 1A1 (CYP1A1), CYP2D6 and phase II metabolic enzymes such as glutathione S-transferase M1 (GSTM1) and GSTT1 and gastric carcinoma susceptibility were investigated. Genomic DNA was isolated from the peripheral blood of 129 healthy controls and 123 gastric carcinoma patients from Han ethnic group of Hunan Province located in Central South China. The genetic polymorphisms of the above mentioned enzymes were analyzed using PCR-RFLP techniques. There was no significant difference among the frequencies of CYP1A1 and/or CYP2D6 gene's wild type, heterozygous or homozygous mutations between the gastric carcinoma group and control group. But the differences among the frequencies of GSTM1 and GSTT1 null genotype between the gastric carcinoma and control group were significant (both P < 0.05). Also there were significant differences in the frequencies of GSTM1 null in high/high-middle differentiated, middle differentiated, middle-low differentiated and low differentiated gastric tumor separately. GSTM1 null showed an increased risk in middle-low differentiated and low differentiated gastric carcinoma type, but GSTT1 null was not a risk factor for the four pathological types of gastric carcinoma mentioned above. We report here that the genotypes of CYP1A1 and CYP2D6 are not associated with gastric carcinoma risk; GSTM1 null, but not GSTT1 null inheritably increases risk of some pathological types of gastric carcinoma in Han ethnic population of Hunan Province.

Resveratrol induces depletion of TRAF6 and suppresses prostate cancer cell proliferation and migration.

Although the early diagnosis of prostate cancer (PCa) enhances life expectancy with a 5-year survival rate of 100 %, metastasized-PCa is the fundamental reason for death by PCa, hence requires an advanced and target-directed treatment strategy. Metastasis is considered to be initiated with the epithelial-mesenchymal transition (EMT) event in which tumor cells change their epithelial characteristics into mesenchymal form and exacerbates the cancer progression. Herein, we investigated the effect and mechanism of resveratrol function in PCa cell proliferation and migration and reported that TNF-receptor associated factor 6 (TRAF6), an unconventional E3 ligase, is a key mediator of resveratrol function to inhibit PCa cell growth and proliferation and targeted for lysosomal degradation by resveratrol. MTT and cell counting demonstrated that resveratrol inhibited the viability and proliferation in DU145 and PC3 cells. Resveratrol (50 µM) mediated the degradation of TRAF6 which in turn facilitated repression of the NF-κB pathway. Also, wound healing and transwell migration assays and level of EMT-related proteins showed that resveratrol used TRAF6, at least in part to inhibit cell migration. Overexpression of TRAF6 augmented EMT in PCa by upregulating the expression of transcription factor SLUG. Moreover, TRAF6 overexpression was closely associated with EMT process through the NF-κB pathway. Our exploration exhibited that resveratrol may inhibit EMT through the TRAF6/NF-κB/SLUG axis. Altogether, this study represents that TRAF6 acts as an intermediary of resveratrol action to suppress PCa cell proliferation and migration, and concerns future attention to obtain as a therapeutic target for the treatment of PCa.

ISG15 inhibits cancer cell growth and promotes apoptosis.

Cervical cancer is one of the most common causes of cancer-related mortality in women in developing countries. Interferon (IFN)-α has been widely used in the treatment of various types of cancer, including cervical cancer, and IFN-stimulated gene 15 (ISG15), an ubiquitin-like protein, is upregulated by IFN-α treatment. The anti-virus and antitumor effects of ISG15 have been reported; however, its mechanism of action have not yet been fully elucidated. In this study, HeLa cells were used as a model system to investigate the roles of ISG15 in IFN-α-mediated cancer cell growth inhibition and induction of apoptosis. The results revealed that both p53 and p21 were upregulated in HeLa cells treated with IFN-α or in the HeLa cells overexpressing ISG15. In addition, the expression levels of ubiquitin-like modifier-activating enzyme 7 (UBA7, also known as UBE1L; ISG15 E1-activating enzyme), UBCH8 (ISG15 E2-conjugating enzyme) and HERC5 (ISG15 E3-ligase) were elevated in the HeLa cells treated with IFN-α. The levels of p53 in the HeLa cells were attenuated by transient transfection with small interfering RNA (siRNA) targeting ISG15 (ISG15-siRNA). Cell viability was inhibited by both IFN-α treatment and ISG15 overexpression. However, these effects were significantly diminished when p53 was knocked down, suggesting that the effects of inhibitory effects of ISG15 on HeLa cell growth and the induction of apoptosis were p53-dependent. Taken together, these results suggest the existence of the IFN-α/ISG15/p53 axis in cervical cancer cells and any strategies manipulating the levels of ISG15 may thus prove to be effective in the treatment of cervical cancer.

Effects of a Particular Heptapeptide on the IFN-α-Sensitive CML Cells.

Using the phage display biopanning technique, we have previously identified a heptapeptide KLWVIPQ which specifically binds to the surface of the IFN-α-sensitive but not the IFN-α-resistant CML cells. The effects of this heptapeptide on the IFN-α-sensitive CML cells were investigated in the present study. IFN-α-sensitive KT-1/A3 and IFN-α-resistant KT-1/A3R CML cells were transfected by pEGFP-KLWVIPQ expression vector and/or induced by IFN-α. WST-1 cell proliferation assay, flow cytometry, and western blotting were performed to determine the effects of this heptapeptide and/or IFN-α on CML cells. The viability of the KT-1/A3 cells was inhibited and apoptosis was induced by either expression of the heptapeptide KLWVIPQ or IFN-α treatment with concurrent upregulation of P53 and downregulation of P210(bcr/abl). However, these effects were not observed in the IFN-α-resistant KT-1/A3R cells. These results suggest that the heptapeptide KLWVIPQ shares a similar mechanism with IFN-α in the regulation of CML cell growth and apoptosis, implying that the heptapeptide KLWVIPQ could be a novel target to go further into mechanisms of IFN-α sensitivity and/or resistance in CML.

Ubiquitination involved enzymes and cancer.

Ubiquitination is a post-translational modification process that regulates multiple cell functions. It also plays important roles in the development of cancer. Mechanistically, ubiquitination is a complex process that is comprised of a series of events involving ubiquitin-activating enzymes, ubiquitin-conjugating enzymes and ubiquitin ligases. In general, covalent attachment of ubiquitin to the target proteins marks them for degradation. Dysregulation of the ubiquitination process may cause carcinogenesis. In this review, we summarize recent developments in understanding the relationship between ubiquitination enzymes and carcinogenesis.

Prostate cancer: current treatment and prevention strategies.

ABSTRACT: Prostate cancer is one of the life threatening disorders of male. Although, over the last two decades, a high rate of overdiagnosis, and overtreatment has lowered the incidence rate of prostate cancer, the treatment or prevention strategies are not enough to control the high rate of disease related mortality. Current medical treatment approaches include surgery, radiation therapy, chemotherapy, hormonal therapy, cryosurgery and other methods. These approaches are more or less effective either as monotherapy or in multimodal approach. However, many adverse or side effects exist with these strategies. Researches are ongoing to find out the way or better strategies to eliminate the adverse effects. Dietary modifications may also contribute to decrease prostate cancer risk. Several nutraceuticals against prostate cancer have also been identified. This review article summarizes some of the current treatment, and prevention strategies with the protection of prostate cancer, which may be helpful to control and prevent this highly frequent life threatening disease.

Effects of rosiglitazone on the growth and lymphangiogenesis of human gastric cancer transplanted in nude mice.

Gastric cancer mainly metastasizes via lymphatic vessels. Thus, it is critical to identify efficacious chemopreventive agents for lymphangiogenesis. The present study was undertaken to explore the effects of rosiglitazone (ROSI) on the growth and lymphangiogenesis of human gastric cancer. We established a model of gastric cancer by subcutaneously inoculating the human gastric cancer cell line SGC-7901 into nude mice. Mice were randomly divided into 4 groups and each group received a different agent by oral gavage. The control group received normal saline and treatment groups received different doses of ROSI once every 2 days. The growth of the tumor in vivo was assessed by measuring tumor volume. After 42 days, the mice were sacrificed and the tumors were removed. H&E staining was used to observe the histomorphological features; immunohistochemistry staining for lymphatic vessel density (LVD) was used to evaluate tumor lymphangiogenesis, RT-PCR was performed to determine the mRNA expression of vascular endothelial growth factor C (VEGF-C) and VEGF receptor-3 (VEGFR-3), and western blotting was used to detect the protein expression of VEGF-C and VEGFR-3. Compared with the control group, all treatment groups had smaller tumor volume and higher tumor growth inhibitory rate every day. The number of typical tumor cells in the control group was higher compared to that in the treatment groups, and the highest level of LVD was found in the control group. Furthermore, both the expression of VEGF-C and VEGFR-3 mRNA and proteins in the control group were significantly higher compared to those in the treatment groups. Markedly, these changes were correlated in a dose-dependent manner with ROSI. These results demonstrated that, through simultaneously blocking the expression of VEGF-C and VEGFR-3, ROSI suppresses lymphangiogenesis. This may represent a powerful therapeutic approach for controlling gastric cancer cell growth and metastasis.

Regulatory effects of resveratrol on antioxidant enzymes: a mechanism of growth inhibition and apoptosis induction in cancer cells.

Resveratrol (RSV) is a natural polyphenol that is known as a powerful chemopreventive and chemotherapeutic anticancer molecule. This study focused on the effects of RSV on the activities and expression levels of antioxidant enzymes in the cancer cells. Prostate cancer PC-3 cells, hepatic cancer HepG2 cells, breast cancer MCF-7 cells and the non-cancerous HEK293T kidney epithelial cells were treated with a wide range of RSV concentrations (10-100 µM) for 24-72 h. Cell growth was estimated by trypan blue staining, activities of the antioxidant enzymes were measured spectrophotometrically, expression levels of the antioxidant enzymes were quantified by digitalizing the protein band intensities on Western blots, and the percentage of apoptotic cells was determined by flow cytometry. Treatment with a low concentration of RSV (25 µM) significantly increased superoxide dismutase (SOD) activity in PC-3, HepG2 and MCF-7 cells, but not in HEK293T cells. Catalase (CAT) activity was increased in HepG2 cells, but no effect was found on glutathione peroxidase (GPX) upon RSV treatment. RSV-induced SOD2 expression was observed in cancer cells, although the expression of SOD1, CAT and GPX1 was unaffected. Apoptosis increased upon RSV treatment of cancer cells, especially in PC-3 and HepG2 cells. Together, our data demonstrated that RSV inhibits cancer cell growth with minimal effects on non-cancerous cells. We postulate that the disproportional up-regulation of SOD, CAT and GPX expression and enzymatic activity in cancer cells results in the mitochondrial accumulation of H2O2, which in turn induces cancer cell apoptosis.

Genetic polymorphisms of metabolic enzymes CYP1A1, CYP2D6, GSTM1 and GSTT1 and leukemia susceptibility.

The genetic polymorphisms of biotransformation phase I enzymes, cytochrome P450 (CYP1A1 and CYP2D6), and phase II enzymes, glutathione S-transferase (GSTM1 and GSTT1), were analyzed in 204 healthy persons and 348 leukemia patients, who suffered from also acute lymphoblastic leukemia (ALL), acute nonlymphoblastic leukemia (ANLL) chronic myelogenous leukemia (CML), from the Han ethnic group in Changsha City of Hunan Province of China. Our results showed that the frequencies of polymorphisms of CYP1A1, CYP2D6 and GSTT1 among the groups including acute lymphoblastic leukemia, ANLL, chronic myelogenous leukemia and healthy control have no significant differences. The variation of GSTM1-null genotype alone correlated with the development of ANLL. The combined genotypes of GSTM1-null with GSTT1-null, or GSTM1-null with CYP1A1 heterozygous mutant, or GSTM1-null with CYP1A1 heterozygous mutant and CYP2D6 heterozygous mutant, or GSTM1-null with CYP1A1 heterozygous mutant, CYP2D6 heterozygous mutant and GSTT1-null were found in individuals with high risk of ANLL. All these findings suggest that GSTM1-null genotype alone or in coordination with the relevant genotypes of other metabolic enzymes might be susceptibility factors in the etiology of ANLL.