The establishment of the two dimensional gel electrophoresis (2-DE) map of hypertrophic scar epidermal cells and the display of the differentially expressed proteins / 中华整形外科杂志

<p><b>OBJECTIVE</b>To establish and optimize the two dimensional gel electrophoresis (2-DE) map of epidermal cells separated from the hypertrophic scar tissues so as to explore the function of the non cultured epidermal cells during the course of the formation of hypertrophic scar.</p><p><b>METHODS</b>To separate the epidermal cells from the scar tissues, the scar epidermis was digested with Dispase II and trypsin. The total protein of the cells was then extracted and separated with 2-DE and visualized with silver stain. Spots detection and matching were performed with Melaine 3.0 gels analyzing software. The results were then compared with the normal epidermal cells' 2-DE map coming from the Danish Center for Human Genome Research' s 2-DE PAGE Databases.</p><p><b>RESULTS</b>Nearly more than 600 protein spots were identified in the final optimized 2-DE map. We found out 24 differentially expressed proteins by comparing the difference in composition, shape or density of all the spots. In the 24 proteins, there are 8 up-regulated ones, 9 down-regulated ones, 4 disappeared ones and 3 newly founded ones.</p><p><b>CONCLUSIONS</b>The method of digesting the epidermis with Dispase II and trypsin to separate the epidermal cells to establish the 2-DE map is feasible and it made the further study on hypertrophic scar proteomics possible. The 24 differentially expressed proteins revealed that epidermal cells might play a role in the formation of hypertrophic scar.</p>

The expression and possible function of RhoA in human gastric cancer cell lines / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the expression and possible function of RhoA in human gastric cancer cell lines.</p><p><b>METHODS</b>The expression of RhoA in human gastrointestinal cancer cell lines was detected by Western blot. Antisense plasmid of RhoA was constructed by pGEFL and transferred into gastric cancer cell line AGS by lipofectamine. Cell survival was examined by MTT assays, and cell cycle was detected by flow cytometry.</p><p><b>RESULTS</b>The expression of RhoA protein in 10 different kinds of human cancer cell lines was much higher than that in immortalized human intestinal epithelial cell line. After being transfected with antisense RhoA, with the decrease in RhoA protein expression, the growth rate of AGS was inhibited, and the number of cells in S phase was increased by 14%.</p><p><b>CONCLUSION</b>RhoA is overexpressed in many human cancer cell lines. Some of the malignant characteristics of a gastric cancer cell line can be partially reversed by inhibiting RhoA expression.</p>

Expression and significance of DARPP-32 in gastric carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the significance of DARPP-32 protein expression in gastric carcinoma tissue and cell lines.</p><p><b>METHODS</b>The expression of DARPP-32 protein in normal gastric mucosa and gastric carcinoma tissue was evaluated by immunohistochemical staining using streptavidin-biotin complex technique. The expression in gastric carcinoma tissue and cell lines was evaluated by Western blotting.</p><p><b>RESULTS</b>The expression rate of DARPP-32 protein in gastric adenocarcinoma tissue (92.7%) was significantly higher than that in normal gastric mucosa (52.6%, P < 0.05). There was no significant association between DARPP-32 protein expression and degree of tumor differentiation, local invasion and distant metastasis. As compared with adjacent non-carcinomatous gastric mucosa, both DARPP-32 and its truncated isoform t-DARPP were overexpressed in gastric adenocarcinoma tissue (t = 2.45, P = 0.015); and t-DARPP overexpression was more frequently seen. Expression of DARPP-32 and t-DARPP could also be detected in human gastric cancer cell lines. The expression of DARPP-32 protein was obviously reduced in SGC7901 drug-resistant cell strains.</p><p><b>CONCLUSIONS</b>DARPP-32 is overexpressed in gastric carcinoma. It may play an important role in gastric carcinogenesis. The underlying signal pathways in neoplastic gastric epithelium may also be related to the multi-drug resistance property of gastric cancer cells.</p>

Expressions and activities of Rho GTPases in hypoxia and its relationship with tumor angiogenesis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the expressions and activities of Rho GTPases in hypoxia and its relationship with tumor angiogenesis.</p><p><b>METHODS</b>Three tumor cell lines were used in this study: gastric cancer cell lines AGS, SGC7901 and hepatocellular carcinoma cell line HepG2. Expression level of Rac1 mRNA was detected by semi-quantitative RT-PCR. Activity of Rac1 was determined by pull-down assay and expression of HIF-1alpha, VEGF, p53 and PTEN protein was detected by Westernblot.</p><p><b>RESULTS</b>The expression level of Rac1 mRNA was significantly increased in hypoxia compared to normoxia. Pull-down assay showed that hypoxia-induced activity of Rac1 was elevated in a time-dependent manner and climaxed at 3 hours. The expressions of HIF-1alpha and VEGF protein were up-regulated, while those of PTEN and p53 protein were down-regulated.</p><p><b>CONCLUSION</b>These results indicate that hypoxia enhances Rac1 expression which might be involved in tumor angiogenesis by reacting with hypoxia-responsive genes.</p>

Expression and function of zinc ribbon gene ZNRD1 in drug-resistant gastric cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the expression and function of zinc ribbon gene ZNRD1 in drug-resistant cells of gastric cancer.</p><p><b>METHODS</b>Two tumor cell lines were used in this study: gastric cancer SGC7901 and its drug-resistant counterpart SGC7901/VCR stepwise-selected by vincristine. The expression of ZNRD1 in SGC7901 and SGC7901/VCR was detected by northern blot and semiquantitative RT-PCR. ZNRD1 antisense nucleic acid was transfected into SGC7901/VCR cells by lipofectamine. The expression of protein in SGC7901/VCR cells and the transfectants was detected by immunochemical method. Fluorescence activated cell scan (FACS) was applied to observe the cell cycle alteration. Growth curve and drug sensitization of cells for vincristine (VCR) and adriamycin (ADM) were analyzed by MTT assay.</p><p><b>RESULTS</b>The expression of ZNRD1 was higher in SGC7901/VCR than in SGC7901 cells. Immunochemical results showed that the expression level of ZNRD1 protein was lower in anti ZNRD1-SGC7901/VCR cells than in non-transfectants. The anti ZNRD1-SGC7901/VCR cells were gradually accumulated in G(1) phase, with a concomitant decrease of cell population in S phase. MTT assay showed that transfectant cell proliferation was lagged and more sensitive to VCR and ADM than non-transfectants.</p><p><b>CONCLUSION</b>ZNRD1 gene displays high expression in VCR resistant gastric cancer cells. Expression of ZNRD1 protein is effectively blocked in anti ZNRD1-SGC7901/VCR cells by gene transfection. ZNRD1 antisense nucleic acid could reverse, to some degree, the MDR of human drug-resistant gastric cancer cell SGC7901/VCR.</p>

Rac subfamily expression and activity in gastrointestinal cancer cell lines / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the significance of Rac subfamily members in the gastrointestinal carcinogenesis and progression.</p><p><b>METHODS</b>The mRNA expression of Rac1, Rac2 and Rac3 in 12 kinds of gastrointestinal cancer cell lines was examined by semi-quantitative RT-PCR. The activities of Rac1 protein in 5 kinds of gastric cancer cell lines were tested by pull-down assay.</p><p><b>RESULTS</b>Compared with the normal gastric mucosa and intestinal epithelial cell line, the mRNA expression of Rac1 and Rac3 was up-regulated in most of gastrointestinal cancer cell lines. The activities of Rac1 protein increased markedly in gastric cancer cell lines.</p><p><b>CONCLUSION</b>The increased mRNA expression of Rac1 and Rac3 in gastrointestinal cancer cell lines and the abnormal activation of Rac1 protein in gastric cancer cell lines might be correlated with the carcinogenesis of gastrointestinal cancer.</p>

Protective effect of selective cyclooxygenase-2 inhibitor on alcohol-induced liver injury in rats / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To investigate the effect of selective cyclooxygenase-2 (COX-2) inhibitor on alcohol-induced liver injury in rats.</p><p><b>METHODS</b>58 male Wistar rats were randomly divided into three groups: control group treated with dextrose and corn oil, model group with ethanol and corn oil, treatment group with corn oil and ethanol plus a selective COX-2 inhibitor celecoxib. All treatments were injected into stomach through intragastric tubes. Liver samples were analyzed for histopathology with light microscope (LM) and transmission electron microscope (TEM), and the expression of COX-2 with western blotting. Levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum, levels of 6-Keto-prostaglandin F1 alpha (6-k-PGF1a) and thromboxane B2 (TXB2) in liver, and activity of glutathione s-transferase (GST) both in liver tissue and in plasma were measured.</p><p><b>RESULTS</b>LM and TEM indicated hepatocytes were injured obviously in the model group and slightly in the treatment group. The levels of AST and ALT in serum, TXB2 in liver and the activity of GST in plasma increased significantly in the model group (t> or =2.294, P<0.05), but the activity of GST in liver decreased significantly (t=8.856, P<0.01) compared with those in the control group. To compare with the model group, the levels of AST and TXB2 decreased significantly (t=4.305, P<0.01; t=2.799, P<0.01), meanwhile the activity of GST increased significantly (t=10.134, P<0.01) in the treatment group. COX-2 expression in liver by western blotting increased significantly in the model group, compared with the control group (t=4.067, P<0.01) and the treatment group (t=2.251, P<0.05). Exceptionally, the level of 6-k-PGF1a decreased significantly (t=2.284, P<0.05) in the model group.</p><p><b>CONCLUSION</b>COX-2 has involved in the alcohol-induced liver injury, and its inhibitor can diminish alcohol-induced liver injury in rats through decreasing TXB2 level</p>