RNAi-mediated silencing of CD147 inhibits tumor cell proliferation, invasion and increases chemosensitivity to cisplatin in SGC7901 cells in vitro

<p>Abstract</p> <p>Background</p> <p>CD147 is a widely distributed cell surface glycoprotein that belongs to the Ig superfamily. CD147 has been implicated in numerous physiological and pathological activities. Enriched on the surface of many tumor cells, CD147 promotes tumor growth, invasion, metastasis and angiogenesis and confers resistance to some chemotherapeutic drugs. In this study, we investigated the possible role of CD147 in the progression of gastric cancer.</p> <p>Methods</p> <p>Short hairpin RNA (shRNA) expressing vectors targeting CD147 were constructed and transfected into human gastric cancer cells SGC7901 and CD147 expression was monitored by quantitative realtime RT-PCR and Western blot. Cell proliferation, the activities of MMP-2 and MMP-9, the invasive potential and chemosensitivity to cisplatin of SGC7901 cells were determined by MTT, gelatin zymography, Transwell invasion assay and MTT, respectively.</p> <p>Results</p> <p>Down-regulation of CD147 by RNAi approach led to decreased cell proliferation, MMP-2 and MMP-9 activities and invasive potential of SGC7901 cells as well as increased chemosensitivity to cisplatin.</p> <p>Conclusion</p> <p>CD147 involves in proliferation, invasion and chemosensitivity of human gastric cancer cell line SGC7901, indicating that CD147 may be a promising therapeutic target for gastric cancer.</p

Synthetic emmprin peptides with chitobiose substitution stimulate MMP-2 production by fibroblasts

<p>Abstract</p> <p>Background</p> <p>Emmprin, a glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells. Its first Ig domain (ECI) contains the biologically active site. The dependence of emmprin activity on N-glycosylation is controversial. We investigated whether synthetic ECI with the shortest sugar is functionally active.</p> <p>Methods</p> <p>The whole ECI peptides carrying sugar chains, a chitobiose unit or N-linked core pentasaccharide, were synthesized by the thioester method and added to fibroblasts to examine whether they stimulate MMP-2 production.</p> <p>Results</p> <p>ECI carrying a chitobiose unit, ECI-(GlcNAc) ₂, but not ECI without a chitobiose unit or the chitobiose unit alone, dose-dependently stimulated MMP-2 production by fibroblasts. ECI with longer chitobiose units, ECI-[(Man)₃(GlcNAc)₂], also stimulated MMP-2 production, but the extent of its stimulation was lower than that of ECI-(GlcNAc)₂.</p> <p>Conclusions</p> <p>Our results indicate that ECI can mimic emmprin activity when substituted with chitobiose, the disaccharide with which N-glycosylation starts.</p

Upregulated EMMPRIN/CD147 might contribute to growth and angiogenesis of gastric carcinoma: a good marker for local invasion and prognosis

Tumour growth depends on angiogenesis, which is closely associated with vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Extracellular MMP inducer (EMMPRIN) was reported to involve in the progression of malignancies by regulating expression of VEGF and MMPs in stromal cells. To clarify the role of EMMPRIN in progression and angiogenesis of gastric carcinoma, expression of EMMPRIN, ki-67, MMP-2, MMP-9 and VEGF was examined on tissue microarray containing gastric carcinomas (n=234) and non-cancerous mucosa adjacent to carcinoma (n=85) by immunohistochemistry. Additionally, microvessel density (MVD) was assessed after labelling with anti-CD34 antibody. Extracellular MMP inducer expression was compared with clinicopathological parameters of tumours, including levels of ki-67, MMP-2, MMP-9 and vascular endothelial growth factor (VEGF), MVD as well as survival time of carcinoma patients. Gastric carcinoma cell lines (HGC-27, MKN28 and MKN45) were studied for EMMPRIN expression by immunohistochemistry and Western blot. Extracellular MMP inducer expression was gradually increased from normal mucosa to carcinomas through hyperplastic or metaplastic mucosa of the stomach (P<0.05). There was strong EMMPRIN expression in all gastric carcinoma cell lines despite different levels of glycosylation. Extracellular MMP inducer expression was positively correlated with tumour size, depth of invasion, lymphatic invasion, expression of ki-67, MMP-2, MMP-9 and VEGF of tumours (P<0.05), but not with lymph node metastasis, UICC staging or differentiation (P>0.05). Interestingly, there was a significantly positive relationship between EMMPRIN expression and MVD in gastric carcinomas (P<0.05). Survival analysis indicated EMMPRIN expression to be negatively linked to favourable prognosis (P<0.05), but not be independent factor for prognosis (P>0.05). Further analysis showed three independent prognostic factors, depth of invasion, lymphatic and venous invasion, to influence the relationship between EMMPRIN expression and prognosis. Upregulated expression of EMMPRIN possibly contributes to genesis, growth and local invasion of gastric carcinomas. Altered EMMPRIN expression might enhance growth, invasion and angiogenesis of gastric carcinoma via upregulating MMP expression of both stromal fibroblasts and gastric cancer cells and could be considered as an objective and effective marker to predict invasion and prognosis

Co-expression of CD147 (EMMPRIN), CD44v3-10, MDR1 and monocarboxylate transporters is associated with prostate cancer drug resistance and progression

Background: The aim of this study is to seek an association between markers of metastatic potential, drug resistance-related protein and monocarboxylate transporters in prostate cancer (CaP). Methods: We evaluated the expression of invasive markers (CD147, CD44v3-10), drug-resistance protein (MDR1) and monocarboxylate transporters (MCT1 and MCT4) in CaP metastatic cell lines and CaP tissue microarrays (n=140) by immunostaining. The co-expression of CD147 and CD44v3-10 with that of MDR1, MCT1 and MCT4 in CaP cell lines was evaluated using confocal microscopy. The relationship between the expression of CD147 and CD44v3-10 and the sensitivity (IC50) to docetaxel in CaP cell lines was assessed using MTT assay. The relationship between expression of CD44v3-10, MDR1 and MCT4 and various clinicopathological CaP progression parameters was examined. Results: CD147 and CD44v3-10 were co-expressed with MDR1, MCT1 and MCT4 in primary and metastatic CaP cells. Both CD147 and CD44v3-10 expression levels were inversely related to docetaxel sensitivity (IC50) in metastatic CaP cell lines. Overexpression of CD44v3-10, MDR1 and MCT4 was found in most primary CaP tissues, and was significantly associated with CaP progression. Conclusions: Our results suggest that the overexpression of CD147, CD44v3-10, MDR1 and MCT4 is associated with CaP progression. Expression of both CD147 and CD44v3-10 is correlated with drug resistance during CaP metastasis and could be a useful potential therapeutic target in advanced disease

Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis

Background: Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis. Methods: Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry. Results: All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting. Conclusion: These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC.This work was supported by the Fundação para a Ciência e a Tecnologia (FCT) grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘Programa Operacional Temático Factores de Competitividade’ (COMPETE) of ‘Quadro Comunitário de Apoio III’ and co-financed by the Fundo Europeu De Desenvolvimento Regional (FEDER). Ricardo Amorim was recipient of the fellowship SFRH/BD/98002/2013, from Fundação para a Ciência e a Tecnologia (FCT Portugal).info:eu-repo/semantics/publishedVersio

Muscle-specific loss of Bmal1 leads to disrupted tissue glucose metabolism and systemic glucose homeostasis

BACKGROUND: Diabetes is the seventh leading cause of death in the USA, and disruption of circadian rhythms is gaining recognition as a contributing factor to disease prevalence. This disease is characterized by hyperglycemia and glucose intolerance and symptoms caused by failure to produce and/or respond to insulin. The skeletal muscle is a key insulin-sensitive metabolic tissue, taking up ~80 % of postprandial glucose. To address the role of the skeletal muscle molecular clock to insulin sensitivity and glucose tolerance, we generated an inducible skeletal muscle-specific Bmal1(−/−) mouse (iMSBmal1(−/−)). RESULTS: Progressive changes in body composition (decreases in percent fat) were seen in the iMSBmal1(−/−) mice from 3 to 12 weeks post-treatment as well as glucose intolerance and non-fasting hyperglycemia. Ex vivo analysis of glucose uptake revealed that the extensor digitorum longus (EDL) muscles did not respond to either insulin or 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) stimulation. RT-PCR and Western blot analyses demonstrated a significant decrease in mRNA expression and protein content of the muscle glucose transporter (Glut4). We also found that both mRNA expression and activity of two key rate-limiting enzymes of glycolysis, hexokinase 2 (Hk2) and phosphofructokinase 1 (Pfk1), were significantly reduced in the iMSBmal1(−/−) muscle. Lastly, results from metabolomics analyses provided evidence of decreased glycolytic flux and uncovered decreases in some tricarboxylic acid (TCA) intermediates with increases in amino acid levels in the iMSBmal1(−/−) muscle. These findings suggest that the muscle is relying predominantly on fat as a fuel with increased protein breakdown to support the TCA cycle. CONCLUSIONS: These data support a fundamental role for Bmal1, the endogenous circadian clock, in glucose metabolism in the skeletal muscle. Our findings have implicated altered molecular clock dictating significant changes in altered substrate metabolism in the absence of feeding or activity changes. The changes in body composition in our model also highlight the important role that changes in skeletal muscle carbohydrate, and fat metabolism can play in systemic metabolism