Proteomic research of biomarker of colorectal cancer metastasis / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the potential markers of colorectal cancer metastasis and the influence of 5-FU on differentially expressed proteins by using proteomic technology, and to elucidate the mechanism of colorectal cancer metastasis.</p><p><b>METHODS</b>Human colorectal carcinoma cell lines of different metastatic potential, Lovo and SW480 were conventionally cultured, and the protein was extracted. 50% inhibitory concentration (IC(50)) of 5-FU to these two cell lines was measured by MTT assay. Proteins of these two cell lines after intervention by 5-FU at IC(50) were extracted, then 2-dimensional gel electrophoresis was conducted for the proteins. The differential protein spots were examined by mass spectrometry and analyzed by bioinformatics. Difference of expressed proteins in two cell lines before and after the intervention of 5-FU was validated by Western blot and immunofluorescence.</p><p><b>RESULTS</b>Eleven differentially expressed proteins were identified by 2-dimensional gel electrophoresis and mass spectrometry. The hnRNP K protein and PDI were selected to be examined by Western blot and immunofluorescence. Results revealed that the expression of hnRNP K in Lovo was higher than that in SW480, while the expression of PDI was lower in Lovo. After intervention by 5-FU at IC(50), the expression of hnRNP K in Lovo decreased more as compared to SW480, while the expression of PDI in SW480 increased more as compared to Lovo.</p><p><b>CONCLUSION</b>There are significant differences in expression of hnRNP K and PDI proteins between Lovo and SW480 cell lines, and the proteins alter regularly after 5-FU intervention.</p>

Influences of enteral nutrition combined with probiotics on the gut microecology and barrier function of the rats with abdominal infection / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the influences of enteral nutrition (EN), parenteral nutrition (PN) and probiotics supplement on the intestinal microecology, and barrier function of the rats with abdominal infection.</p><p><b>METHODS</b>Twenty-one Sprague-Dawley (SD) rats with abdominal infection were randomly divided into three groups, and received PN (PN group, n=7), PN+ EN (PN+ EN group, n=7) or PN+ EN+ probiotics (probiotics group, n=7) respectively with isonitrogen and isocaloric nutrition. The rats were sacrificed after six days. The feces in cecum were cultured for anaerobic bacterial growth and DNA fingerprint spectrum was analyzed by randomly amplified polymorphic DNA technique. The transmembrane binding protein (occludin) and IgA levels in colon and terminal ileum were detected by immunohistochemistry method. The bacterial translocation rate and endotoxin level were also measured.</p><p><b>RESULTS</b>The germ numbers of different species were both higher in PN+ EN and probiotic group than those in PN group. The bands of DNA fingerprint spectrum were significantly decreased in PN group, but the bands in both PN+ EN group and probiotic group were similar to that in the normal rats. The expression levels of occludin and IgA in the intestine and colorectum were higher in both PN+ EN group and probiotic group compared with those of PN group (P< 0.05, P< 0.01, respectively), the expression level of occludin was higher in probiotic group than that in PN+ EN group (P< 0.05). The overall bacterial translocation rates and endotoxin levels were significantly reduced in both probiotic and PN+ EN group (P< 0.05), but there was no difference between probiotic group and EN group.</p><p><b>CONCLUSION</b>EN combined with probiotics can increase occluding and IgA expressions, improve the intestinal microecology,maintain the gut barrier function, and decrease the incidence of gut bacterial translocation.</p>