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Observation of targeting lymphocytes to therapy nude mice bearing KATOⅢ gastric cancer cell

Objective To study effect of carcinoembryonic antigen (CEA) positive targeted lymphocytes on gastric cancer cells in vitro and in vivo. Methods The peripheral blood mononuclear cells (PBMCs) were isolated from the peripheral blood of healthy volunteers. The recombinant vector anti-CEA-scFv-CD3ζ-pcDNA3.0 was transfected into the PBMCs by lipofectamine 2000, by this means, the CEA special lymphocytes were obtained. Meanwhile, the PBMCs transfected with empty plasmid pcDNA3.0 were used as control (empty vector lymphocytes). The different lymphocytes and gastric cancer cells (CEA positive KATOⅢ gastric cancer cells and CEA negative BGC-823 gastric cancer cells) were co-cultured, then the ability to identify the gastric cancer cells and it’s effect on apoptosis of gastric cancer cells were observed at 24 h or 36 h later respectively. The CEA special lymphocytes and empty vector lymphocytes were injected by the tail vein of nude mice bearing gastric cancer cells, then it’s effect on the tumor was observed. Results ① The CEA special lymphocytes could strongly identify the KATOⅢ gastric cancer cells (identification rate was 72.3%), which could weakly identify the BGC-823 gastric cancer cells (identification rate was 7.8%). ② The apoptosis rate of the co-culture of CEA special lymphocytes and KATOⅢ gastric cancer cells was significantly higher than that of the co-culture of empty vector lymphocytes and KATOⅢ gastric cancer cells (P=0.032), which had no significant difference between the co-culture of CEA special lymphocytes and BGC-823 gastric cancer cells and the co-culture of empty vector lymphocytes and BGC-823 gastric cancer cells (P=0.118). ③ The tumor volume of the co-culture of CEA special lymphocytes and KATOⅢ gastric cancer cells was significantly smaller than that of the co-culture of empty vector lymphocytes and KATOⅢ gastric cancer cells (F=5.010, P<0.01) or the co-culture of CEA special lymphocytes and BGC-823 gastric cancer cells (F=4.982, P<0.01), which had no significant difference between the co-culture of CEA special lymphocytes and BGC-823 gastric cancer cells and the co-culture of empty vector lymphocytes and BGC-823 gastric cancer cells (F=1.210, P>0.05). Conclusion CEA special lymphocytes can promote cell apoptosis and inhabit tumor reproduction of CEA positive gastric cancer cells in vitro and in vivo.

Construction and Identification of Fluorescent Protein Expression Vector with Chimeric Molecule in T Lymphocytes

Objective　To construct a green fluorescent protein expression plasmid pEGFP-C3-anti-TAG72 scFv-CD28, containing anti-TAG72 single chain variable fragment (scFv) fused into the transmembrane and intracellular domain of the signal-transducing chain of CD28 gene, and to transfect it into peripheral blood mononuclear cells． Methods　Recombinant transmembrane and intracellular domain of CD28 cDNA and anti-TAG72 scFv cDNA fragment was subcloned into pEGFP-C3 vector. Recombinant clones were selected by Kanamyein， and then identified by PCR， enzyme digestion analysis and DNA sequencing. The recombinant plasmid was transfected into peripheral blood mononuclear cells by means of lipofection. The recombinant protein expression was confirmed by immunocytochemistry, laser scanning confocal microscope, PCR and Western blot analysis. Results　The fused gene fragment of anti-TAG72 scFv-CD28 was successfully inserted into pEGFP-C3 plasmid, and it was confirmed by enzyme digestion and DNA sequencing. The fused anti-TAG72 scFv-CD28 gene and its protein was identified in peripheral blood mononuclear cells． Conclusion　The eukaryotic expression plasmid pEGFP-C3-anti-TAG72 scFv-CD28 was successfully constructed and transiently expressed in peripheral blood mononuclear cells， which would lay a foundation for further studies on the role of it to activate tumor-associated antigen-specific T lymphocyte, for generating of modified T lymphocytes targeting gastrointestinal tumors.

前部增殖性玻璃体视网膜病变

Antitumor Responses of TAG-72 Redirected T Lymphocytes to Breast Cancer

Objective　To investigate the effect of tumor associated glycoprotein-72 （TAG-72） redirected T lymphocytes on breast cancer cells. Methods　Peripheral blood mononuclear cells （PBMCs）were isolated from healthy volunteers. The recombinant vector anti-TAG-72-scFv-CD3ζ-pcDNA 3.0 were transfected into PBMCs by lipofectamineTM2000 （transfection group）， PBMCs transfected with plasmid pcDNA 3.0 as control group. MCF-7 and Bcap37 cells were cocultivated with PBMCs of transfection group and control group， respectively， and antitumor response of G1 block was observed. Results　G1 block rate of MCF-7 cells in transfection group was （82.3±6.9）%， which was significantly higher than that in control group 〔（43.4±3.9）%， P＜0.05〕. G1 block rate of Bcap37 cells in transfection group was （51.3±4.7）%， and not differed from that in control group 〔（45.6±2.5）%， P＞0.05〕. Conclusion　TAG-72 redirected T lymphocytes can inhibit the cell proliferation of TAG-72 positive breast cancer cells， and it may provide valuable tools for the cellular immunotherapy.

Repression Effects of Anchor Chemric T Lymphocytes on Proliferation of Tumor Associated Glycoprotein 72 Positive Hepatocarcinoma Cells

ObjectiveTo investigate the method for generating anchor chemric T lymphocytes that can target tumor associated glycoprotein-72 (TAG72) antigen and analyze their repressive effects on proliferation of TAG72 positive hepatocarcinoma cells. MethodsFirstly, peripheral blood mononuclear cells (PBMCs) from healthy volunteers were isolated. And then, CD8+ T cells were isolated from PBMCs via magnetic activated cell sorting (MACS). These lymphocytes were transfected with recombinant vector, anti-TAG72-scFv-CD28-pcDNA3, through Lipofectamine2000 to gernerate anchor chimeric TAG72-specific CD8+ T cells. SMMC7721 (TAG72 positive) hepatocarcinoma cells were co-cultured with chimeric T lymphocytes and their cell cycles were analyzed by flow cytometry (FCM). ResultsAnchor chmeric T lymphcytes targetting TAG72 recognized TAG72 positive SMM7721 cells and repressive effects on their proliferation were observed by flow cytometry. ConclusionAnchor chmeric T lymphcytes targetting TAG72 on tumor surface can specifically recognize TAG72 positive hepatocarcinoma cells and may exert repressive effect on their proliferation.

NEUROPROTECTIVE EFFECTS OF MANGIFERIN ON ACUTE SPINAL CORD INJURY IN RATS AND ITS MECHANISM

ObjectiveTo investigate the protective effect of mangiferin on acute spinal cord injury (SCI) in rats and its mechanism. MethodsNinety Sprague Dawley rats were randomly divided into 5 groups, 18 rats in each group. SCI was induced by using the Allen's method (60 g/cm) at T9 level in the rats of groups B, C, D, and E; laminectomy was performed at T8-10 in group A. The rats were injected intraperitoneally with saline in groups A and B, and with mangiferin in groups C (10 mg/kg), D (25 mg/kg), and E (50 mg/kg) every day for 30 days. The survival condition of rats was observed after operation; at 24, 48, and 72 hours after operation, the motor function of the hind limb was evaluated by the Basso, Beattie, Bresnahan (BBB) scores. The spinal cord edema was assessed by measuring the water content in spinal cord tissues at 72 hours. Meanwhile, malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) were detected by ELISA; nuclear factor κB (NF-κB), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 were measured via ELISA at the same time. Caspase-3 and Caspase-9 were also detected by ELISA after mangiferin treatment for 30 days. The expressions of Bax and Bcl-2 proteins were detected by Western blot. Pathological changes of the spinal cord was observed by HE staining. And Caspase-3 protein expression was detected by immunohistochemical staining. ResultsAll rats survived to the end of experiment. BBB scores of groups B, C, D, and E were significantly less than that of group A (P < 0.05), and it showed an increase trend from groups B to E (P < 0.05). The content of water of groups B, C, D, and E were significantly greater than that of group A (P < 0.05), and it showed a decrease trend from groups B to E (P < 0.05). ELISA showed that the activities of MDA, NF-κB, TNF-α, IL-1β, IL-6, Caspase-3, and Caspase-9 in groups B, C, D, and E were significantly greater than that in group A (P < 0.05), and they showed decrease trends from groups B to E (P < 0.05). Meanwhile, the activities of CAT, SOD, and GSH in groups B, C, D, and E were significantly less than that in group A (P < 0.05), and they showed increase trends from groups B to E (P < 0.05). Western blot showed that the relative expression of Bax protein in groups B, C, D, and E were significantly greater than that in group A (P < 0.05), and it showed a decrease trend from groups B to E (P < 0.05). Meanwhile, the relative expression of Bcl-2 protein in groups B, C, D, and E were significantly less than that in group A (P < 0.05), and it showed an increase trend from groups B to E (P < 0.05). Histological observation showed that the pathological changes in group B were accord with that in SCI, and the degree of necrosis in groups C, D, and E were significantly improved when compared with that in group B, and the effect was better in group E than group D, and group D than group C. Immunohistochemical staining showed that the absorbance (A) value of Caspase-3 in groups B, C, D, and E were significantly greater than that in group A (P < 0.05), and it showed a decrease trend from groups B to E (P < 0.05). ConclusionMangiferin has neuroprotective effects on acute SCI in rats by alleviating edema of spinal cord, inhibiting oxidative stress and inflammation response, and regulating the Bcl-2 and Bax pathway.

Prokaryotic Expression of Anti-TAG-72 Single-Chain Variable Fragment and Its Value in Detection of Hepatocellular Carcinoma

Objective To study the prokaryotic expression of the anti-tumor associated glycoprotein-72 (TAG-72) singlechain fragment variable (scFv) antibody and its specific affinity to hepatocellular carcinoma cell lines and tissues. Methods The cDNA of anti-TAG-72 scFv antibody was inserted into pCANTAB5E to obtain phage vector anti-TAG-72 -scFv-pCANTAB5E. Isopropyl-β-D-thiogalactoside (IPTG) was used to induce the expression of anti-TAG-72 scFv antibody. SDS-PAGE and Western blot were used to identify the anti-TAG-72 scFv antibody. Human hepatocellular carcinoma cells were cultured, and TAG-72 was determined with the obtained scFv by immunohistochemistry in the cells and paraffin-embedded hepatocellular carcinoma tissues. Results SDS-PAGE and Western blot showed that the anti-TAG-72-scFv antibody was successfully expressed. Anti-TAG-72 scFv could bind to hepatocellular carcinoma cell lines SMMC7721, HepG2, and HHCC, but not to BEL7402, suggesting that SMMC7721, HepG2, and HHCC cells expressed TAG-72. For the 40 cases of hepatocellular carcinoma tissues, the positive rate of TAG-72 in stage Ⅰ and Ⅱ-Ⅲ was 23.08% (3/13) and 62.96%(17/27), respectively. While no TAG-72 expression was found in the 10 normal cases. TAG-72 expression was significantly different between hepatocellular carcinomas and normal tissues (Plt;0.05). Conclusions The prokaryotic expression of anti-TAG-72 scFv antibody is successfully achieved, and can be used to identify TAG-72 antigen. TAG-72 is highly expressed in hepatocellular carcinoma, but not in normal liver tissue, which may be suggested as cancer marker of hepatocellular carcinoma.

Construction and Expression of Hepatocellular CarcinomaSpecific Expressing Eukaryotic Vector for AntiAngiogenesis Therapy

Objective　To construct a mammalian vector encoding angiostatin kringle 5 (K5) under the control of αfetoprotein （AFP） enhancer and albumin promoter, and to observe the expression of angiostatin by introducting angiostatin gene into hepatocellular carcinoma cells through gene transfection. Methods　Angiostatin cDNA was amplified from normal human eukaryotic cells by using RTPCR. Meanwhile, AFP enhancer and albumin promoter sequences were directed cloned and were inserted into vector pcDNA3.1. The recombinant vector of pcDNA3.1AFABangiostatin K5His was constructed, which contained the angiostatin K5 cDNA sequence that was under the control of the AFP enhancer and promoter. Angiostatin K5 cDNA was introduced into human AFP positive hepatocellular carcinoma cell lines with the transfected cultured cells that were mediated with Lipofectamine 2000. The expression of angiostatin K5 was analyzed by Western blot and the protein was dectected with antiHis antibody. Results　The 500base pair of angiostatin K5 was in accordance with the expected sequence and the recombinant vector of pcDNA3.1AFABangiostatin K5His was also confirmed as the anticipated sequence. The expression of angiostatin K5 in AFP positive hepatocellular carcinoma cells was detected both by SDSPAGE and Western blot. Conclusion　Efficient construction and expression of angiostatin K5 to AFP positive cells make it possible for antiangiogenesis therapy of human hepatocellular carcinomas, which may provide a promising approach.

Comparison of Seromuscular Layer Anastomosis， Extramucosal Anastomosis， Single-Layer Anastomosis and Double-Layer Anastomosis of Gastrointestinal Tract in Rabbits

Objective　The effects of seromuscular layer anastomosis， extramucosal anastomosis，single-layer anastomosis and double-layer anastomosis of gastrointestinal tract on anastomotic healing were compared. Methods　Chinese rabbits were divided into four groups: group A (double-layer anastomosis, n=10), group B (single-layer inverted anastomosis, n=10), group C (extramucosal anastomosis, n=10) and group D (seromuscular layer anastomosis, n=10). Five anastomoses were performed in each animal: one side-to-side gastroduodenal anastomosis, two end-to-end ileal and colonic anastomoses respectively. Half of each group was sacrificed on postoperative day 3 and 7 respectively to determine in situ anastomostic bursting pressures (ABP) and hydroxyproline (HP) content, and to receive histopathologic examination. Inflammatory index and mucosal healing index of anastomosis were calculated. Results　There were no significant differences in case of ABP among the groups on day 3, and with the same result among group A, B and C on day 7 in gastroduodenal, ileoileal and colocolonic anastomoses. On day 7, the ABP of gastroduodenal anastomosis was dramatically higher in group D than group A and B (P＜0.05), the ABP of ileoileal anastomosis in group D was significantly increased compared with group A (P＜0.01), and the ABP of colocolonic anastomosis in group D was also higher than group A, B and C (P＜0.05). There was no statistical difference in HP content among the 4 groups in gastroduodenal and ileal anastomoses on day 3 (Pgt;0.05), and in ileal and colonic anastomoses on day 7 (Pgt;0.05). HP content was higher in group A than group B on day 3 in colonic anastomoses (P＜0.05),　 and it was also found to be higher in group D than group A on day 7 in gastroduodenal anastomosis (P＜0.025). Inflammatory reaction was not different among the 4 groups in gastroduodenal and ileoileal anastomoses on day 3, and the inflammatory indices of gastroduodenal and colocolonic anastomoses in all groups were similar on day 7. The inflammatory index of colocolonic anastomosis was signicantly increased in group A than group C on day 3 (P＜0.05), and that of ileoileal anastomosis in group A was higher than group D on day 7 (P＜0.05).　 The mucosal healing indices of anastomoses were not significantly different among the 4 groups on day 7. Conclusion　Seromuscular layer anastomosis of gastrointestinal tract is as safe as other hand-sewn anastomoses, but it is more convenient and simpler than others.