Cytoplasmic Skp2 Expression Is Increased in Human Melanoma and Correlated with Patient Survival

BACKGROUND: S-phase kinase protein 2 (Skp2), an F-box protein, targets cell cycle regulators via ubiquitin-mediated degradation. Skp2 is frequently overexpressed in a variety of cancers and associated with patient survival. In melanoma, however, the prognostic significance of subcellular Skp2 expression remains controversial. METHODS: To investigate the role of Skp2 in melanoma development, we constructed tissue microarrays and examined Skp2 expression in melanocytic lesions at different stages, including 30 normal nevi, 61 dysplastic nevi, 290 primary melanomas and 146 metastatic melanomas. The TMA was assessed for cytoplasmic and nuclear Skp2 expression by immunohistochemistry. The Kaplan-Meier method was used to evaluate the patient survival. The univariate and multivariate Cox regression models were performed to estimate the hazard ratios (HR) at five-year follow-up. RESULTS: Cytoplasmic but not nuclear Skp2 expression was gradually increased from normal nevi, dysplastic nevi, primary melanomas to metastatic melanomas. Cytoplasmic Skp2 expression correlated with AJCC stages (I vs II-IV, P<0.001), tumor thickness (≤2.00 vs >2.00 mm, P<0.001) and ulceration (P = 0.005). Increased cytoplasmic Skp2 expression was associated with a poor five-year disease-specific survival of patients with primary melanoma (P = 0.018) but not metastatic melanoma (P>0.05). CONCLUSION: This study demonstrates that cytoplasmic Skp2 plays an important role in melanoma pathogenesis and its expression correlates with patient survival. Our data indicate that cytoplasmic Skp2 may serve as a potential biomarker for melanoma progression and a therapeutic target for this disease

Luminal membrane expression of mesothelin is a prominent poor prognostic factor for gastric cancer

BACKGROUND: Mesothelin is expressed in various types of malignant tumour, and we recently reported that expression of mesothelin was related to an unfavourable patient outcome in pancreatic ductal adenocarcinoma. In this study, we examined the clinicopathological significance of the mesothelin expression in gastric cancer, especially in terms of its association with the staining pattern. METHODS: Tissue specimens from 110 gastric cancer patients were immunohistochemically examined. The staining proportion and intensity of mesothelin expression in tumour cells were analysed, and the localisation of mesothelin was classified into luminal membrane and/or cytoplasmic expression. RESULTS: Mesothelin was positive in 49 cases, and the incidence of mesothelin expression was correlated with lymph-node metastasis. Furthermore, luminal membrane staining of mesothelin was identified in 16 cases, and the incidence of luminal membrane expression was also correlated with pT factor, pStage, lymphatic permeation, blood vessel permeation, recurrence, and poor patient outcome. Multivariate analysis showed that luminal membrane expression of mesothelin was an independent predictor of overall patient survival. CONCLUSION: We described that the luminal membrane expression of mesothelin was a reliable prognostic factor in gastric cancer, suggesting the functional significance of membrane-localised mesothelin in the aggressive behaviour of gastric cancer cells. British Journal of Cancer (2012) 107, 137-142. doi: 10.1038/bjc.2012.235 www.bjcancer.com Published online 29 May 2012 (C) 2012 Cancer Research U

Novel anti-inflammatory agent 3-[(dodecylthiocarbonyl)-methyl]-glutarimide ameliorates murine models of inflammatory bowel disease

Objective and design: To examine the effect of 3-[(dodecylthiocarbonyl)-methyl]-glutarimide (DTCM-G), a novel anti-inflammatory agent that inhibits lipopolysaccharide (LPS) activation of RAW264.7 macrophages, on murine models of colitis and RAW264.7 cells. Materials and methods: Colitis was induced by rectally infusing trinitrobenzenesulfonic acid (TNBS) (1.5 mg in 50 % ethanol) in BALB/c mice or orally administering 3 % dextran sulfate sodium (DSS) for 5 days in C57BL/6 mice. The severity of colitis was assessed after intraperitoneally injecting DTCM-G (40 mg/kg). The anti-inflammatory properties of DTCM-G and its mechanisms were investigated in LPS-stimulated RAW264.7 cells. Results: DTCM-G significantly ameliorated TNBS-induced colitis, according to the body weight loss, disease activity index, colonic obstruction, macroscopic colonic inflammation score, mucosal myeloperoxidase activity, and histopathology. Immunohistochemistry and isolated lamina propria mononuclear cells showed significantly reduced colonic F4/80+ and CD11b+ macrophage infiltration. DTCM-G significantly suppressed tumor necrosis factor (TNF)-α and interleukin (IL)-6 messenger RNA expression in the colon and attenuated DSS-induced colitis, according to the disease activity index and histopathology. In RAW264.7 cells, DTCM-G suppressed LPS-induced TNF-α/IL-6 production and enhanced glycogen synthase kinase-3β phosphorylation. Conclusions: DTCM-G attenuated murine experimental colitis by inhibiting macrophage infiltration and inflammatory cytokine expression. Thus, DTCM-G may be a promising treatment for inflammatory bowel disease