Effect of Vav3 gene inhibition on inhibitor of apoptosis proteins and multidrug resistance in gastric cancer cells / 第二军医大学学报

Objective To explore the role of Vav3 gene in multidrug resistance (MDR) of gastric cancer and the related mechanism. Methods QRT-PCR was used to examine the expressions of Vav3 gene in gastric cancer tissues, tumor-adjacent tissues, human gastric cancer cell line SGC7901, and gastric epithelial cell line GES-1. Then Vav3-siRNA was synthesized and tansfected into SGC7901 cells. MTT assay was then used to determine the inhibition rates of tumor cells exposed to chemotherapeutic agents (5-FU, L-OHP) before and after Vav 3-siRNA transfection. Realtime RT-PCR and Western blotting analysis were used to observe the expressions of inhibitor of apoptosis proteins (IAPs) : xIAP, Survivin, and Livin; meanwhile, the expression and activity of Caspase-3 and Caspase-8 were also determined. Results Vav3 was over-expressed in gastric cancer tissues and gastric cell line compared with those in tumo-adjacent tissues and gastric epithelial cell line GES-1 (P<0.05). Expression of Vav3 was significantly inhibited by Vav3-siRNA (P<0.01). Inhibition rates of tumor cells exposed to 5-FU and L-OHP were significantly increased 48 h after Vav3-siRNA tansfection (P<0.05). The expressions of xIAP and Survivin were significantly decreased in cancer cells after Vav3-siRNA tansfection (both P<0.05), and no notable change was found for Livin expression; also the expression and activity of Caspase-3 and Caspase-8 protein were significantly increased after Vav3-siRNA tansfection in SGC7901 cells (all P<0.05). Conclusion Vav3 can participate in MDR of gastric cancer by regulating apoptotic pathways, and inhibition of Vav3 can help reverse MDR of gastric cancer cells by regulating some IAPs.

Effect and mechanisms of TET on human gastric carcinoma cell line SGC7901 and SGC7901/ADR / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the effect of tetrandrine (TET) on zinc finger protein 139 (ZNF139) and multidrug resistance (MDR) of human gastric carcinoma cell lines and possible mechanisms.</p><p><b>METHODS</b>Cultured SGC7901 and SGC7901/ADR were treated with TET (0.5, 1.0, 1.5, 2.0, and 2.5 microg/mL), then inhibition rates were measured by MTT assay in vitro. The expressions of ZNF139, MRP-1, MDR1, and GST-pi were detected by RT-PCR. The correlation between ZNF139 and each multidrug resistance factor was analyzed using Spearman correlation analysis, and the coefficient correlation was calculated.</p><p><b>RESULTS</b>The inhibition rate of TET (< or = 2.0 microg/mL) for SGC7901 and SGC7901/ADR was less than 10% with MTT assay. Expressions of ZNF139, MRP-1, MDR1, and GST-pi mRNA were higher in SGC7901/ADR than in SGC7901 (all P < 0.05). The expressions of ZNF139, MRP-1, MDR1, and GST--pi were down-regulated in SGC7901/ADR cells efficiently (all P < 0.01). Positive correlation existed between ZNF139 and MRP-1, ZNF139 and MDR1 before treated by TET in SGC7901/ADR, and this relationship also existed in SGC7901/ADR cells after treated by TET (all P < 0.05).</p><p><b>CONCLUSION</b>TET could achieve MDR reversion in gastric cancer cells by down-regulating the expression of ZNF139, MRP-1, and MDR1.</p>

Effects of XELOX regimen as neoadjuvant chemotherapy on radical resection rate and prognosis in patients with advanced gastric cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The purpose of this study was to investigate the efficacy and mechanism of oxaliplatin in combination with capecitabine (XELOX) regimen as neoadjuvant chemotherapy in the treatment of patients with advanced gastric cancer.</p><p><b>METHODS</b>Eighty-five patients with advanced gastric cancer (stage IIB and IIIC) were randomly divided into two groups: neoadjuvant chemotherapy group (40 cases) and surgery alone group (45 cases). In the neoadjuvant chemotherapy group, patients received oral administration of Xeloda 1000 mg/m(2) twice a day on days 1-14 and intravenous infusion of oxaliplatin 130 mg/m(2) on day 1 (XELOX regimen). The regimen was repeated every 21 days. In the surgery alone group, patients directly received radical resection of gastric cancer. The R0 resection rate, overall survival and disease free survival (DFS) were observed in all cases. The cycles and apoptosis rate of the gastric cancer cells were detected by flow cytometry. The expression of proliferating cell nuclear antigen (PCNA), p21, p53 and survivin was detected by Western blot.</p><p><b>RESULTS</b>In the neoadjuvant chemotherapy group, the total effective rate was 32.5% (13/40), and the tumor control rate was 90% (36/40), with few side effects. Compared with the surgery alone group, R0 resection rate was significantly higher in the neoadjuvant chemotherapy group (P < 0.05). The survival analysis indicated that both the overall survival and DFS were longer in the neoadjuvant chemotherapy group in comparison with those in the surgery alone group, but no significant differences were found (P > 0.05). In the neoadjuvant chemotherapy group, both the apoptosis rate and the ratio of cells in stage G0 and G1 were significantly higher than those in the surgery alone group (P < 0.05). The expression of PCNA and survivin was lower in the neoadjuvant chemotherapy group, while the expression of p21 and p53 was higher.</p><p><b>CONCLUSIONS</b>XELOX regimen as neoadjuvant chemotherapy in the treatment of patients with advanced gastric cancer can effectively improve the R0 resection rate and prolong the survival time of the patients. Its mechanism is probably that the neoadjuvant chemotherapy can markedly enhance apoptosis in gastric cancer cells and inhibit their proliferation.</p>

Integrase interactor 1 regulates proliferation, apoptosis and invasion in gastric cancer cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Integrase interactor 1 (INI1), which encodes a component of the ATP-dependent chromatin remodeling hSWI-SNF complex, has been identified as a tumor suppressor in many tumors. Nonetheless, the role of INI1 in gastric tumor progression is not known exactly. The aim of this research was to investigate the effect of INI1 in the carcinogenesis and progression of gastric cancer.</p><p><b>METHODS</b>Gastric tumor tissues with different differentiation levels from clinical gastric carcinoma samples and adjacent control normal tissues were taken. Expression levels of INI1 were detected by quantitative reverse transcriptation-polymerase chain reaction (RT-PCR) and Western blotting. Gastric cancer cell line SGC7901 was transfected with INI1 eukaryotic expressing vector INI1-GFP. Cell proliferation activities were assessed by MTT; cell count and cell cycle were detected by flow cytometry (FCM); cell apoptosis were measured by TUNEL and FCM; cell migration and invasiveness were evaluated by wound healing and transwell assays. Expression levels of INI1 and proliferation-related genes including p16, p21, cyclin D1 and cyclin A, apoptosis genes p53, B-cell non-Hodgkin lymphoma-2 (Bcl-2), Bcl-2-associated x protein (Bax) and caspase-3, and invasion-related genes including intercellular adhesion molecule 1 (ICAM1), matrix metalloproteinase 2 (MMP2), MMP9 and tissue inhibitor of matrix metalloproteinase 1 (TIMP1), were detected by quantitative RT-PCR and Western blotting.</p><p><b>RESULTS</b>INI1 expression levels were lower in gastric carcinoma compared with adjacent control normal tissues. Overexpression of INI1 in SGC7901 cells inhibited its proliferation and invasiveness, but increased anoikis and G(0)/G(1) cell number. INI1-GFP transfection upregulated expression of INI1 and proliferation related genes p16 and p21, apoptosis genes p53 and Bax, and invasion-related genes TIMP1; cyclin D1, cyclin A, Bcl2, ICAM1, MMP2 and MMP9 were downregulated, and there was no significant change in caspase 3 levels.</p><p><b>CONCLUSION</b>INI1 plays a key role in gastric carcinogenesis by affecting proliferation, apoptosis and invasion.</p>

Effect of antisurvivin oligodeoxynucleotides on proliferation and apoptosis in gastric cancer cell line BGC-823 and the molecular mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the effects of antisense oligodeoxynucleotides (ASODN) on proliferation and apoptosis in gastric cancer cell line BGC-823 cells and the molecular mechanisms induced by ASODN.</p><p><b>METHODS</b>survivin ASODN-1, survivin ASODN-2 and survivin ASODN-3 were transfected into BGC-823 cells by Lipofectamine(TM) 2000 transfection reagent. The growth activity of BGC-823 cells was detected by MTT assay. Apoptosis index (AI), proliferation index (PI), cell cycle and expressions of survivin, VEGF and Smac/DIABLO proteins were detected by flow cytometry (FCM). The changes of survivin mRNA, VEGF mRNA and Smac/DIABLO mRNA were detected by RT-PCR.</p><p><b>RESULTS</b>The expression of survivin was down-regulated by the three ASODN sequences, especially the ASODN-2 was best. At 48 hours after transfection with 600 nmol/L survivin ASODN-2, the cells in G(1)/G(0) phase were significantly increased [(72.25 ± 2.95)%], apoptotic index increased [(11.31 ± 0.38)%], proliferation index decreased [(27.77 ± 2.97)%], compared with those in the control group [(56.25 ± 0.75)%, (1.62 ± 0.36)%, (43.80 ± 0.80)%, all P < 0.05]. The survivin mRNA and protein levels (0.523 ± 0.091, 0.733 ± 0.009) were down-regulated compared with those in the control group (0.861 ± 0.047, 0.997 ± 0.233), VEGF (0.519 ± 0.076, 0.75 ± 0.006) were down-regulated compared with those in the control group (0.779 ± 0.059, 1.000 ± 0.01), while those of Smac/DIABLO(0.899 ± 0.113, 1.637 ± 0.023)were up-regulated compared with those in the control group (0.558 ± 0.041, 1.000 ± 0.049, all P < 0.05).</p><p><b>CONCLUSIONS</b>Survivin ASODN can induce apoptosis and inhibit the proliferation of gastric cancer cell line BGC-823 cells. Those effects are induced through up-regulation of Smac/DIABLO and down-regulation of survivin and VEGF expression simultaneously.</p>

Proteomic identification and comparison of differentiation-related proteins in gastric carcinoma cell lines / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the differentiation-related proteins in human gastric carcinoma cell lines by comparative proteomics.</p><p><b>METHODS</b>The holoproteins of human gastric carcinoma cell lines MKN28, SGC7901 and BGC823 were measured by two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Some proteins identified by proteomics were tested by Western blot in the cell strains and tissues of gastric carcinoma.</p><p><b>RESULTS</b>14 differential protein spots were found in the 3 gastric carcinoma cell lines, among them 8 spots were identified by MALDI-TOF-MS. These proteins were probably thioredoxin peroxidase, glyceraldehyde-3-phosphate dehydrogenase (GAPD), beta-tubulin polypeptide, hypothetical protein, zinc finger protein (ZNF) 139, protein-tyrosine kinase, calreticulin precursor, and tropomyosin, proteins related with biological behavior of gastric carcinoma cells such as signal transduction, cellular homeostasis, glycolysis, antioxidation action, multidrug resistance(MDR), etc. The expressions of those proteins in gastric cancer cells and tissues identified by Western blot were consistent with the results obtained by proteomics.</p><p><b>CONCLUSION</b>Differential proteins are found in 3 human gastric carcinoma cell lines, mainly, proteins related with cell signaling, maintenance of homeostasis, glycolysis, metabolism of anti-cancer drug and anti-oxidative injury, etc.</p>

Expression features of P-glycoprotein, glutathione S transferase-pi and inhibitor of apoptosis proteins in lymph node metastases of gastrointestinal carcinomas / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the expression features of P-glycoprotein (P-gp), glutathione S transferase-pi (GST-pi) and inhibitor of apoptosis proteins like p53, survivin and bcl-2 in lymph node metastases of gastrointestinal carcinomas.</p><p><b>METHODS</b>The expression of P-gp, GST-pi, p53, survivin and bcl-2 were determined by using immunohistochemistry technique in surgical specimens of primary tumor (PT) and lymph node metastases (LNMs) from 54 gastrointestinal cancer patients with metastasis of lymph nodes. The expression difference of 5 multi-drug resistance (MDR)-related factors between LNMs and PT were compared.</p><p><b>RESULTS</b>Significant difference was found in the expression of P-gp and GST-pi between the two groups (both P < 0.05), and expression of p53 and bcl-2 showed positive correlation between LNMs and PT (r = 0.7248, 0.5524; both P < 0.05), respectively. In LNMs, P-gp expression was positively correlated with GST-pi (r = 0.4062, P < 0.05) and survivin (r = 0.6169, P < 0.05), and also GST-pi expression was related positively with survivin (r = 0.4027, P < 0.05). Statistically positive correlations were noted between bcl-2 and P-gp (r = 0.3986, P < 0.05), bcl-2 and survivin (r = 0.2937, P < 0.05), as well as GST-pi and survivin (r = 0.4481, P < 0.01) in PT. Only a positive correlation between GST-pi and survivin expression was simultaneously shown in both LNMs and PT.</p><p><b>CONCLUSIONS</b>There is significant heterogeneity of MDR-related factors expression in LNMs of gastrointestinal carcinomas. Effective adjuvant chemotherapy after operation should target on the metastatic loci of the disease.</p>