Signal transducer and activator of transcription (STAT) 3 is a critical transcription factor for cell proliferation and survival. It is activated within cells by many cytokines to mediate immune and inflammatory responses to injury. Inflammatory bowel disease (IBD), represented by Crohn′s disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease of the intestinal tract. STAT3 has been shown to be abnormally activated in IBD colon tissues by many pro-inflammatory cytokines, leading to disruption of the intestinal mucosal barrier and excessive innate immune and Th17 responses. The persistent chronic inflammation eventually leads to intestinal fibrosis and stenosis. In addition to immune responses, STAT3 is also involved in intestinal fibrosis in IBD by promoting the transcription of fibrosis-related genes. Colitis-associated cancer (CAC) is a particularly aggressive subtype of colorectal cancer and is associated with chronic inflammation-induced IBD. STAT3 has also been associated with CAC initiation and development. STAT3 is overactivated in tumors, which leads to suppression of the anti-tumor activity of immune cells and promotion of cancer cell proliferation, tumor angiogenesis, invasion, and migration. In the present article, we summarize the role of STAT3 in IBD and CAC and the research progress of the related drugs developed for UC and CAC treatment.

OBJECTIVETo evaluate the long-term effect of sodium glycididazole (CMNa) as a hypoxic radiosensitizer on the radiotherapy for nasopharyngeal carcinoma.

METHODSBetween May 1999 and May 2002, 211 patients with pathologically confirmed nasopharyngeal carcinoma were randomized into group-A treated by radiotherapy plus CMNa or group-B by radiotherapy alone. The staging was determined according to 92' Fuzhou staging systerm. The type, procession and dosage of radiotherapy were identical in both groups. The early adverse effect grade was assessed based on the CTC2.0 criteria and the late adverse effects were evaluated according to the RTOG/EORTC criteria. The median follow-up time was 52 months. All the data was analyzed by the SPSS 13.0 software. Characteristics and adverse events of these patients were compared between the two groups using t-test and the Wilcoxin rank sum test. Time-to-event curves were estimated using the Kaplan-Meier method. The prognostic parameters were analyzed using univariate analysis and the Cox multivariate regression analysis.

RESULTSThe clinical data of the two groups were comparable. The 3-year survival was 88.4% in group-A, while 75.2% in group-B, with a statistically significant difference between two groups (P = 0.010). Univariate analysis showed that the 3-year survival was statistically correlated with N-staging ((N0-1, 86.9%, N2-3 73.8%, P < 0.001), T-staging (T1-2 85.6%, T3-4 79.3%, P = 0.014), TNM staging (P = 0.039), and whether using CMNa or not during rediotherapy (Group-A 88.4%, Group-B 75.2%, P = 0.010). The 5-year recurrence-free survival, 5-year metastasis-free survival and 5-year overall survival were 75.8%, 74.9% and 77.7% in Group-A, while 63.0%, 63.0% and 62.4% in Group-B with a statistically significant difference between two groups (0.013, 0.022 and 0.010, respectively). If stratified in the subgroups, the overall survival of stage III - IV patients was statistically different between group A and B (P = 0.009), however, not of stage I - II patients (P = 0.502). Cox multivariate regression analysis showed that the independent prognostic parameters for survival were N-stage (RR = 3.288) , T-stage (RR = 2.147) and use of CMNa during rediotherapy (RR = 0.407). However, there was no statistically significant difference between two groups in acute or late adverse effects on nervous system or heart, which suggested that use of CMNa during radiotherapy would not aggravate the toxicity caused by radiotherapy.

CONCLUSIONSodium glycididazole is well tolerable effective as a hypoxic radiosensitizer, which can improve the efficacy of radiotherapy and the long-term result of nasopharyngeal carcinom a patients, especially for the stage III - IV patients.

Adolescent ; Adult ; Aged ; Female ; Follow-Up Studies ; Humans ; Kaplan-Meier Estimate ; Male ; Metronidazole ; adverse effects ; analogs & derivatives ; therapeutic use ; Middle Aged ; Multivariate Analysis ; Nasopharyngeal Neoplasms ; pathology ; radiotherapy ; Neoplasm Staging ; statistics & numerical data ; Prognosis ; Proportional Hazards Models ; Radiation-Sensitizing Agents ; adverse effects ; therapeutic use ; Time Factors ; Treatment Outcome ; Vomiting ; chemically induced

Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous study found that oral administration of nitazoxanide inhibited Western diet (WD)-induced hepatic steatosis in ApoE^-/- mice. However, the specific mechanism remains to be elucidated. In the present study, we performed an untargeted metabolomics approach to reveal the effect of nitazoxanide on the liver metabolic profiles in WD-fed ApoE^-/- mice, and carried out the cellular experiments to elucidate the underlying mechanisms. UPLC-MS-based untargeted metabolomics analysis was used to investigate the effect of nitazoxanide on global metabolite changes in liver tissues. The differential metabolites were screened for enrichment analysis and pathway analysis. Hepatocytes were treated with tizoxanide, the metabolite of nitazoxanide, to investigate the underlying mechanism based on the findings in metabolomics study. The improvement of liver lipid metabolism disorders by nitazoxanide treatment in WD-fed ApoE^-/- mice was mainly through regulating glycerophospholipid metabolism, D-glutamine and glutamate metabolism, glutathione metabolism, and arginine biosynthesis metabolism. Tizoxanide, the active metabolite of nitazoxanide, increased glutathione (GSH) contents and glutamate-cysteine ligase catalytic subunit (Gcl-c) and glutathione reductase (Gsr) mRNA expressions in HepG2 cells. Tizoxanide increased cystathionine β-synthase (CBS) and phosphatidylethanolamine N-methyltransferase (PEMT) protein levels, inhibited lipid accumulation in hepatocytes induced by free fatty acid (FFA). Tizoxanide increased S-adenosyl-L-homocysteine hydrolase (SAHH) protein levels in HepG2 cells and mouse primary liver cells stimulated with free fatty acid (FFA). Tizoxanide increased N-acetyl glutamate synthase (Nags) and carbamoylphosphate synthetase 1 (Cps1) mRNA expressions in HepG2 cells. In conclusion, nitazoxanide improves WD-induced hepatic steatosis in ApoE^-/- mice and the underlying mechanisms include increasing CBS expression, GSH content, PEMT protein expression, Nags and Cps1 mRNA expression in hepatocytes.