| Gastric cancer is one of the higher morbidity and mortality in ourcountry's malignancies tumor. Current chemotherapy is the main treatment ofadvanced gastric cancer, metastatic gastric cancer recurrence after surgery.Previous studies have shown that cyclooxygenase-2(CyclooXygenase-2,COX-2) and digestive tract tumors, including gastric cancer proliferation,apoptosis, specific COX-2inhibitors such as celecoxib can reduce theexpression of COX-2playing the anti-tumor activity. The Fas system is one ofthe main apoptosis induced by Cell expression of Fas and Fas antibody (Fasantibody, Fas, Ab) or FasL interaction of Fas where the target cell apoptosis,activation of Fas high expression pathway can induce gastric cancer increasedapoptosis. There are few studies on the selective COX-2in gastric cancer cellsat home and abroad.Objective: This study explore the impact of COX-2inhibitors combinedwith fluorouracil for gastric cancer through the determination of COX-2, Fasexpression in the orthotopic transplantation tumors of mouse forestomachcarcinoma cell (MFC) with intervention of celecoxib and fluorouracil in615mice.Methods:1Establishment of615mice MFC orthotopic transplantation model. AnabiosisMFC cell and serial subcultivation, choose the fine growth state cell wereinoculated subcutaneously in615mice back. Take passaged six times theMFC solid tumor blocks were inoculated in the615mice of the stomach,thereby establishing the30gastric carcinoma615mice orthotopicimplantation model.2Celecoxib and fluorouracil interfere with in the the MFC615mouse orthotopic implantation of gastric cancer model.7-9days after orthotopicimplantation in mice MFC615, the upper abdomen can reach3~4mmdiameter of induration expressed the MFC615mice orthotopic implantationmodel was successful, celecoxib (25mg/kg) was given orally and fluorouracil(50mg/kg) by intraperitoneal injection. Observed Mice in each group mentalstate, eating and drinking, activity, weight, etc.615mice were sacrificed afterthe interfere with three weeks, then weighted the tumor nodules, restraintumor rate according to the following formula: restrain tumorrate(%)=(average weigh of contrast group tumour-average weigh ofexperimental group tumour)/average weigh of contrast group tumour x100%.3COX-2protein and Fas protein expression in the orthotopic transplantationtumor cells of the MFC in615mouse intervention with Celecoxib andfluorouracil. Detect the gastric cancer tissues (Celecoxib group, celecoxibcombined with fluorouracil group, orthotopic transplantation in the controlgroup) of COX-2, Fas expression by SP immunohistochemical method.4Statistical analysis. All the data was statistical analysed with SPSS13.0statistical package. Measurement data was represented with the(士s), first forhomogeneity of variance between groups, then used Single factor analysis ofvariance. performed pairwise comparison with SNK method.Immunohistochemistry positive rate applications c2test to inspect level α=0.05.Results:1Establishment of subcutaneously transplanted tumor and the orthotopictransplantation model in the615mice with MFCTransplanted subcutaneously in the first generation of two inoculated MFCcell suspension in the615mice back, after inoculation of tumor cells5to6days,2-3mm diameter of induration at the site of mice inoculated withsubcutaneous palpable.8~10days of tumor increases to a diameter10mm.Subcutaneously transplanted tumor with the increase in the number ofpassages in rodents growth rate has been slowing, subcutaneously transplantedtumor grew to10mm in diameter need8to18days. The sixth generation of subcutaneously transplanted tumor length to diameter10mm takes16to18days. One of the second generation of subcutaneously transplanted tumorfailed. The tissue block passage between transplanted subcutaneously in miceevery two, and12615mouse tissue transplanted subcutaneously into thetumor rate of91.67%. Passaged six times between the mouse subcutaneoustransplanted tumor is stable, with no natural healing, well adapted to the615mice in vivo environment. Passaged six times after subcutaneoustransplantation tumorConduct Orthotopic transplantation.Animal model of orthotopictransplantation in the7to9days on the left side of the abdomen can hit a3~4mm diameter induration, indicating that the in situ modeling.30615mice byorthotopic transplantation was successful in all. Randomly divided into thecelecoxib group, celecoxib combined with fluorouracil group, orthotopictransplantation in the control group (n=10).2Observed behavioral changes in the615mice with MFC orthotopictransplantation by celecoxib, and fluorouracil intervention Agile in theprocess of the drug, celecoxib combined with Fluorouracil group mice hadmild vomiting, mental state, the reaction is more sensitive, normalconsumption of water. The consumption of water is slightly reduced in thecelecoxib group found no vomiting, and activities over the previous slowweight loss is not obvious. Control group of mice with the transplanted tumornodules gradually grew up, the consumption of drinking water, reduced,reduced activities, significant weight loss, poor spirit, the reaction is slow.3The effect to orthotopic transplantation tumor of the MFC in615mice byCelecoxib and fluorouracil3.1Orthotopic implantation of tumor size is basically the same beforetreatment, at the end of the experiment take tumor,the volume of Orthotopicimplantation control group, celecoxib group, celecoxib combined withfluorouracil group were982.76±79.06mm3,325.96±67.22mm3,92.57±43.68mm3; the celecoxib group, celecoxib combined with fluorouracil ontumor volume inhibition rates were66.83%,90.58%; compared with the control group, tumor volume inhibition of celecoxib group, celecoxibcombined with fluorouracil group were significantly increased andsignificantly different (P<0.01). Compared with the celecoxib group,celecoxib combined with fluorouracil on tumor volume inhibition rateincreased significantly and there was significant difference (p <0.05).3.2The tumor weight of orthotopic implantation control group, celecoxibgroup, celecoxib combined with fluorouracil group were1.64±0.11g,0.74±0.13g,0.38±0.08g; the tumor weight inhibition rate of the celecoxib group,celecoxib combined with fluorouracil group were54.57%,76.55%, comparedwith the control group, tumor inhibition of celecoxib group, celecoxibcombined with fluorouracil group were significantly increased andsignificantly different (P <0.01). Compared with the celecoxib group,celecoxib combined with fluorouracil on tumor inhibition rate increasedsignificantly and there was significant difference.3.3Gross morphological observation, the tumor was substantive growth, thetumor capsule is incomplete, unclear boundaries with the surrounding tissue.Control group orthotopic transplantation tumor cut off-white, the central noobvious necrosis; point necrosis is only visible under an optical microscope.The celecoxib group and celecoxib combined with fluorouracil group tumorsection were gray, dull, central scattered visible residual tumor size rangingfrom necrosis, the edge of the necrosis. Optical microscope, the center can beseen large areas of cell necrosis within small amount of residual yet to necrotictumor cells. The volume had varying sizes, common nucleus profiled.4The expression of COX-2protein and Fas protein in the orthotopictransplantation tumor cells of MFC by celecoxib, and fluorouracil in615mice.4.1COX-2protein is mainly expressed in the cancer cell plasma, the positiveexpression of the celecoxib group, celecoxib combined with fluorouracilgroup, orthotopic transplantation control group, respectively,20.0%,10.0%,70.0%. By chi-square test, three sets of positive expression rate of thedifference had statistically significant (c2value was9.3, P <0.05). Comparedwith the control group, COX-2positive expression rate of the celecoxib group and celecoxib combined with fluorouracil group are significant differences.Compared with the celecoxib group, celecoxib combined with fluorouracilgroup of COX-2positive expression rate had no significant difference.4.2Fas protein is expressed in the cancer cell plasma, the positive expressionof the celecoxib group, celecoxib combined with fluorouracil group,orthotopic transplantation control group of60.0%,90.0%,10.0%. By thechi-square test, three sets of positive expression rate of the difference wasstatistically significant (chi-square value was13.1, P <0.01). Compared withthe control group, the Fas positive expression rate of the celecoxib group andcelecoxib combined with fluorouracil group are significant differences.Conclusion:1Established the orthotopic transplantation tumor model, using the MFC cellsuspension inoculated subcutaneously in615mice. Established the orthotopictransplantation tumor model, the MFC cell suspension inoculatedsubcutaneously in615mice,Inoculated in615mouse the stomach with tumor after repeating mousepassage operation with good controllability and contrast, a higher rate ofsuccessful transplantation, tumor formation time is short, closer to the truepathological state.2Application of Selebi celecoxib intervention can inhibit the growth oforthotopic transplantation tumor, tumor cell necrosis in the light microscope.The combination of fluorouracil is more effective.3Application of celecoxib intervention, the COX-2protein expression in theorthotopic implantation of tumor cells to reduce, inhibit tumor cellproliferation, expression of Fas protein expression, and promote apoptosis oftumor cells. The mechanism may be reduced expression of COX-2, Fasupregulation.4Celecoxib combined with fluorouracil can reduce the expression of COX-2protein in the orthotopic transplantation tumor, but with the single celecoxibwas no statistically significant differences. |
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