Ubiquitin-specific proteases: From biological functions to potential therapeutic applications in gastric cancer.

Deubiquitination, a post-translational modification regulated by deubiquitinases, is essential for cancer initiation and progression. Ubiquitin-specific proteases (USPs) are essential elements of the deubiquitinase family, and are overexpressed in gastric cancer (GC). Through the regulation of several signaling pathways, such as Wnt/ß-Catenin and nuclear factor-κB signaling, and the promotion of the expression of deubiquitination- and stabilization-associated proteins, USPs promote the proliferation, metastasis, invasion, and epithelial-mesenchymal transition of GC. In addition, the expression of USPs is closely related to clinicopathological features, patient prognosis, and chemotherapy resistance. USPs therefore could be used as prognostic biomarkers. USP targeting small molecule inhibitors have demonstrated strong anticancer activity. However, they have not yet been tested in the clinic. This article provides an overview of the latest fundamental research on USPs in GC, aiming to enhance the understanding of how USPs contribute to GC progression, and identifying possible targets for GC treatment to improve patient survival.

Crizotinib changes the metabolic pattern and inhibits ATP production in A549 non-small cell lung cancer cells.

Crizotinib, an inhibitor of the hepatocyte growth factor receptor oncogene, has been studied extensively regarding its antitumor and clinically beneficial effects in non-small cell lung cancer (NSCLC). However, crizotinib's effects on cancer cell energy metabolism, which is linked with tumor proliferation and migration, in NSCLC are unclear. Therefore, the present study focused on crizotinib's effect on NSCLC glucose metabolism. Crizotinib's effects on glucose metabolism, proliferation, migration and apoptosis in A549 cells were explored. Several other inhibitors, including 2-DG, rotenone and MG132, were used to define the mechanism of action in further detail. Data showed that crizotinib treatment reduced A549 cell viability, increased glucose consumption and lactate production, while decreased mitochondrial transmembrane potential (Δψm) and ATP production. Crizotinib treatment, combined with rotenone and MG132 treatment, further inhibited ATP production and Δψm and increased reactive oxygen species content. However, crizotinib did not suppress cell proliferation, migration, ATP production, Δψm or mitochondrial-related apoptosis signals further following 2-DG-mediated inhibition of glycolysis. These results indicated that crizotinib induced low mitochondrial function and compensatory high anaerobic metabolism, but failed to maintain sufficient ATP levels. The alternation of metabolic pattern and insufficient ATP supply may serve important roles in the metabolic antitumor mechanism of crizotinib in A549 cells.

Marsdeniae tenacissima extract-induced growth inhibition and apoptosis in hepatoma carcinoma cells is mediated through the p53/nuclear factor-κB signaling pathway.

An extract from a traditional Chinese herb, Marsdeniae tenacissima (trade name, Xiao-Ai-Ping) has been approved for use on the Chinese market as a cancer chemotherapeutic agent for decades. Previous studies have demonstrated the cytostatic and pro-apoptotic effects of M. tenacissima extract (MTE) in multiple cancer cells. However, the contributions of MTE to the proliferation and apoptosis of hepatoma carcinoma cells and the underlying mechanisms remain unclear. In the present study, Bel-7402 cells were incubated with increasing concentrations of MTE ranging from 0-320 µl/ml to explore the effects and potential mechanisms of MTE on the proliferation and apoptosis of Bel-7402 cells. 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, inner salt and propidium iodide (PI)-stained flow cytometry assays demonstrated that MTE significantly suppressed the proliferation of Bel-7402 cells in a dose-dependent manner by arresting the cell cycle at S phase (P<0.05). Annexin V-fluorescein isothiocyanate PI-stained flow cytometry confirmed the significantly pro-apoptotic effect of MTE at both 160 and 240 µl/ml (P<0.001). Reverse transcription-quantitative polymerase chain reaction and western blot analysis demonstrated that MTE (both 160 and 240 µl/ml) induced a significant downregulation of B-cell lymphoma (Bcl)-2 (P<0.01), upregulation of Bcl-2-associated X protein (P<0.01) and activation of caspase-3 (P<0.05). Furthermore, a significant downregulation of murine double minute-2 (MDM2) (P<0.001) and activation of p53 (P<0.001) in Bel-7402 cells following treatment with 160 or 240 µl/ml MTE was observed, accompanied by the inhibition of the nuclear factor (NF)-κB pathway (P<0.001). These results suggested that MTE inhibited growth and exhibited pro-apoptotic effects in Bel-7402 cells, which was mediated by downregulation of the MDM2-induced p53-dependent mitochondrial apoptosis pathway and blocking the NF-κB pathway. Overall, these data serve as preliminary identification of the significant roles of MTE in hepatic carcinoma cells, and suggest that MTE may be a promising candidate for hepatocellular carcinoma therapy.

Hyperechoic demarcation line between a tumor and the muscularis propria layer as a marker for deciding the endoscopic treatment of gastric submucosal tumor.

Minimally invasive endoscopic resection has been rapidly adopted as a new technique for treating patients with gastric submucosal tumors (SMTs) originating in the muscularis propria (MP) layer. This study was conducted to evaluate the information obtained from endoscopic ultrasonography (EUS) to determine the appropriate endoscopic dissection method for treating SMTs originating in the MP layer. Between February 2014 and May 2016, a total of 50 patients with gastric SMTs originating in the MP layer were enrolled in this study. The clinical features of the patients and their endoscopic, EUS, and histopathologic findings, as well as their postoperative follow-up data, were analyzed in this retrospective study. The mean age of the patients was (55.0±10.2) years, and the male/female ratio was 17:33. Endoscopic submucosal dissection (ESD) was performed on 43 patients and an endoscopic full-thickness resection (EFR) was performed on seven patients. The most frequent location for an SMT was in the upper body region of the stomach (n=16), and the most common pathological diagnosis was a gastrointestinal stromal tumor (GIST) (n=32). The overall rates for complete resection were 95.3% (41/43) and 100.0% (7/7) when the SMTs were treated by ESD and EFR, respectively. The presence of a complete tumor capsule was significantly associated with a complete resection (P=0.001). Of the cases treated by ESD, nine patients developed perforation, one of whom required laparoscopic surgery. The remaining patients were closed with clips or purse-string sutures. The presence of an MP2-type tumor (P=0.018) and a wide connection with the MP layer (P=0.044) were significantly associated with perforation. A preoperative evaluation of the integrity and the location of a tumor capsule and the length of the tumor connection with the MP layer by EUS can improve the complete resection rate and reduce the occurrence of intraoperative complications. Tumors with a complete capsule originating from the superficial MP layer or with a narrow connection with the MP layer are appropriate candidates for treatment by ESD.

Cytotoxicity of anti-tumor herbal Marsdeniae tenacissimae extract on erythrocytes.

Marsdeniae tenacissimae extract (MTE) has been used as an adjuvant medicine for cancer therapy for a long time. Although massive studies demonstrated its considerable anti-cancer effect, there is no research on its influence on erythrocytes, which are firstly interacted with MTE in the circulation. To investigate the influence of MTE on erythrocytes, we used a flow cytometer to detect the MTE-treated alternations of morphology, calcium concentration, and reactive oxygen species (ROS) level in erythrocytes. We used hemolysis under different osmotic solutions to evaluate the fragility of erythrocytes. Data showed that MTE treatment dose-dependently increased the ratio of erythrocyte fragmentation (P<0.001) and shrinking, and elevated the forward scatter (FSC) value (P<0.001) and calcium accumulation (P<0.001). MTE induced ROS production of erythrocytes under the high glucose condition (P<0.01) and consequently caused a rise in fragility (P<0.05). These results suggest that MTE induces cytotoxicity and aging in erythrocytes in a dose-dependent manner, and presents the possibility of impairment on cancer patients' circulating erythrocytes when MTE is used as an anti-cancer adjuvant medicine.

[Protective effect of astaxanthin against epididymal oxidative damagein rats with ornidazole-induced oligoasthenozoospermia].

OBJECTIVE: To investigate the improving effect of astaxanthin (AST) on the sperm quality of rats with ornidazole (ORN)-induced oligoasthenozoospermiaand its action mechanism. METHODS: Forty adult male SD rats were equally randomized into groups A (solvent control), B (low-dose ORN ï¼»400 mg/（kg·d）］), C (high-dose ORN ï¼»800 mg/（kg·d）］), D (low-dose ORN ï¼»400 mg/（kg·d）］ + AST ï¼»20 mg/（kg·d）］), and E (high-dose ORN ï¼»800 mg/（kg·d）］ + AST ï¼»20 mg/（kg·d）］), all treated intragastrically for3 weeks.After treatment, the epididymal tails ononeside was taken for determination of sperm concentration and activity, and the epididymideson the other side harvested for measurement of the activities of GSH-Px, GR, CAT and SOD and the MDA contentin the homogenate. RESULTS: Compared with group A, sperm motilityin the epididymal tail andGSH-Px and SOD activities in theepididymiswere markedly decreased while the MDAcontent significantlyincreased in group B (P<0.05), spermmotility and concentrationin the epididymal tail, testisindex, and the activities of GSH-Px, GR, CAT and SOD in the epididymis were remarkably reduced while theMDA contentsignificantly increased in group C(P<0.05). In comparison with group B, group D showed markedly increased sperm motility (ï¼»45.3±8.7ï¼½% vs ï¼»66.3±8.9ï¼½%, P<0.05) in the epididymal tail and SOD activity in the epididymis (ï¼»116.7±25.3ï¼½ U/mg prot vs ï¼»146.1±23.8ï¼½ U/mg prot, P<0.05), decreased MDA content(ï¼»1.68±0.45ï¼½ nmol/mg prot vs ï¼»1.19±0.42ï¼½ nmol/mg prot, P<0.05).Compared with group C, group Eexhibited significant increases in the weight gained (ï¼»89.0±9.5ï¼½ vs ï¼»99.9±4.1ï¼½ %, P<0.05) and sperm motility (ï¼»17.9±3.5ï¼½% vs ï¼»27.3±5.3ï¼½ %, P<0.05) but a decrease in the content of MDA (ï¼»2.03±0.30ï¼½ nmol/mg prot vs ï¼»1.52±0.41ï¼½ nmol/mg prot, P<0.05). CONCLUSIONS: AST can improve spermquality in rats with ORN-inducedoligoasthenozoospermia, which may be associated with its enhancing effect on the antioxidant capacity of the epididymis.

Marsdeniae tenacissimae extract (MTE) suppresses cell proliferation by attenuating VEGF/VEGFR2 interactions and promotes apoptosis through regulating PKC pathway in human umbilical vein endothelial cells.

Marsdeniae tenacissimae extract (MTE), commonly known as Xiao-Ai-Ping in China, is a traditional Chinese herb medicine capable of inhibiting proliferation and metastasis and boosting apoptosis in various cancer cells. However, little is known about the contribution of MTE towards tumor angiogenesis and the underlying mechanism. The present study aimed to evaluate the effects of MTE on the proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) and the molecular mechanism. 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, inner salt (MTS) and PI-stained flow cytometry assays revealed that MTE dose-dependently reduced the proliferation of HUVECs by arresting cell cycle at S phase (P < 0.05). Annexin V-FITC/PI-stained flow cytometry confirmed that MTE (160 µL·L-1) enhanced the apoptosis of HUVECs significantly (P < 0.001). Real-time quantitative RT-PCR and Western blot analyses showed an increase in Bax expression and a sharply decline in Bcl-2 expression; caspase-3 was activated simultaneously in a dose-dependent manner (P < 0.05). Further study observed the dose-dependent down-regulation of vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2), P2Y6 receptor (P2Y6R), and chemokine (C-C motif) ligand 2 (CCL-2), along with the activation of PKC Δ and up-regulation of p53 in a dose-dependent manner in MTE-treated selected cells (P < 0.05). Collectively, the results from the present study suggested that MTE suppressed the proliferation by attenuating CCL-2-mediated VEGF/VEGFR2 interactions and promoted the apoptosis through PKCΔ-induced p53-dependent mitochondrial pathway in HUVECs, supporting that MTE may be developed as a potent anti-cancer medicine.