Immune Nutrients Dha Collaborative 5-fu Inhibition Of Gastric Cancer In Basic Research And Enteral Nutrition Therapy To Improve The Prognosis Of Postoperative Gastric Cancer Clinical Research

[Background]DHA belongs to family ofω-3 polyunsaturated fatty acids(ω-3 Pufas). Studys documented that it can improve nutrition status as energic substrate,moreover it can prohibit the growth of variety of tumor cells in vitro.However,there are arguments as to whether it would inhibit all kinds of tumor or not,and some researchers proposed that its anticancer effect has cell-specific.Besides,we found EPA,another kind ofω-3 Pufas could enhance the sensitive of gastric cancer cell to epirubicin.But we stil uncertained the relative mechanism of synergism.Therefore,we attempted to investigate the effects of DHA in combination with fluorouracil(FU) on gastric cancer.[Purpose]To investigate the effects of DHA plus FU on gastric cancer and human gastric cancer xenograft in vitro and in vivo.We also wanted to demonstrate the relative mechanism of anticancer effects of DHA in combination with FU on gastric cancer.[Methods]1.In vitro:MTT assessment was used to evaluate the effects of two anticancer agents on gastric cancer and human embryonic fibroblast.According to principle of Chou-Talaly,median of dose of two agents was calculated,furthermore, combination index was evaluated the relationship of two agents combination.In the fowllowing,DHA,FU and its combianton was used to intervene the gastric cell respectively for 24h,then①Transwell was used to assay change of gastric cancer invasive capability;②FCM determined cell cycle;③TBARS was determined the MDA level,lipid peroxidation index;④flurescent probe DCF was used to assay the reactive oxygen species(ROS) standard;⑤AnnexinV-FITC/PI double stained was used to assay apoptotic cells;⑥Western Blot was used to determine target protein effected by agents.2.In vivo:Omegaven,which is DHA-rich lipid emulsion,was used to combine with FU to intervene human gastric cancer xenograft rat model for 21 days.Growth of rat and change of weight of rat,as well as xenograft weight and volume change,were recorded during course of experiment.Western Blot was used to determine the bcl-2 protein expression in xenograft.[Results]In vitro:1.Low dose of DHA had little effect on proliferation of human embryonic lung fibroblast.2.Low dose of DHA had effects on proliferation of SGC7901 and MGC803.The prohibition exhibited dose- and time- dependent manner.3.Low dose of DHA plus FU exhibited strong prohibiton effect,and both of their Dm were decreased when used in combination manner,and when the prohibition ratio reached above 30%,two agents showed synergistic effect(CI＜1)4.DHA and FU could inhibit invasive ability of SGC7901 in Transwell insert.5.DHA plus FU could arrest cell cycle in phase of G0/G1.6.DHA could induce LPO in SGC7901,but FU did not have such effect.Combinations did not induce MDA level increasing comparing to DHA alone,P＞0.05.40μg/ml VitC did not prohibit growth of SGC7901,and when cells were pretreated with VitC at this concentration,LPO was attenuated,at the same time synergism of DHA and FU was abrogated.7.DHA(30,60μg/ml) could induce higher intracellular Ros than FU(12.5,25μg/ml) did, and combination would produce the highest intracellular Ros than any agents alone,P＜0.05.8.Combination of two agents could induce more apoptotic cells than did any agents alone,P＜0.05.9.Western Blot showed FU upregulated bcl-2 and did not nearly affect the expression of cox2,while DHA could reverse FU's effects and promote caspase-3 expression.Total effect of the combinations downregulated bcl2,cox2,Mn SOD and upregulated caspase-3.In vivo:1.Comparing to control group,Omegaven did not promote growth of xenograft.FU in combination with Omegaven could prohibit growth of xenograft.2.Loss of rat weight in FU group was more serious than any group.Omegaven additive to FU could help to protect weight loss.3.Western Blot showed FU in combination with DHA downregulated bcl-2 more significantly than any agents used alone.[Conclusion]1.In vitro,DHA did not promote growth of gastric cancer and at certain concentration it could inhibit growth of cancer cells whilst killed normal cells.Based on the concentration standard,it did not equal to common chemotherapeutic agents.2.DHA in combination with FU could synergistically prohibit gastric cancer.DHA additive to FU would not attenuate cytotoxicity of FU.3.Synergism of two agents perhaps involved in arresting cells cycle,inducing LPO and producing intracellular Ros so as to induce apoptotic cells,bcl-2,cox2,Mn SOD downregulated and caspase-3 upregulated might account for the molecular mechanism of synergism.4.Omegaven,which is DHA-rich lipid emulsion,was documented that it did not induce growth of xenograft,and Omegaven plus FU would prohibit growth of tumor significantly.By comparision with FU alone,Omegagven additive to FU could protect body weight in rat model.Possible mechanism was involved in apoptosis induced by Omegaven plus FU,according to Western Blot analysis. [Background]Curative gastrectomy has been the first procedure for gastric cancer all the time.However,not all the patients have survived for long time since the operation.It is therefore no wonder there has been many factors affecting the survival rate of postgastrectomy,such as tumor features,curative operation or not,perhaps including combined therapy.As we know,gastric cancer is very popular with malnutrition.It is about 200 patients being performaced operation in Peking Union Medical College Hospital each year.In order to improve the approach for gastric cancer,we hereby retrospectively analyzed survival rate and clinic outcome of enteral nutrional intervention during a short term in postgastrectomy gastric cancer patients.[Purpose]We analyzed 120 postoperative gastric cancer patients in 1-year,3-year,5-year survival rate and disclosed independent hazard factors for survive.Simultaneously,we attempted to analyze beneficial outcome for postoperative patients with intensive enteral nutrition support within 3-6 months through jejunostomy tube feeding.[Methodology]120 patients undergoing gastrectomy from 2002 to 2003 were assigned into survival analysis.Besides,an enteral nutritional intervention comparative analysis was carried out.29 patients with jejunostomy tube and 32 patients without jejunostomy tube were compared with respect to body weight loss,chemotherapeutic tolerance and NRS 2002 improvement.Clinic data and survival data were registerd through Epidata3.0 which is epidemiologic software.[Results]1.Survival analysisKaplan-Meier analysis results showed that postgastrectomy survival rate of 1-year,3-year, 5-year was 89.7%,45.1%,28.9%,respectively.1-year,3-year,5-year survival rate of gastric sinus cancer was 94.0%,65.9%,42.0%.And the survival rate of 1-year,3-year, 5-year was 94.1%,82.0%,57.4%,respectively,inⅠ+Ⅱstage which was defined accoding to UICC,median survival time was 68.0±0.000m;89.1%,45.5%,21.6%inⅢstage,median survival time was 33±6.092m;81.4%,12.6%,8.4%inⅣstage and median survival time 21±1.906m.(P=0.000,log-rank test)②Log rank test showed there are many independent hazard factors impairing prognosis, including age(P=0.043),lymphadectomy(P=0.000),blood loss(P=0.025),blood transfusion(P=0.000),location of tumor,tumor size,tumor differential,lymphonode metastasis,tumor stage(P=0.000).③Logistic regression and cox regression showed that tumor size(Exp(β)/RR=1.598), lymphonode metastasis(Exp(β)/RR=1.599),tumor stage(Exp(β)/RR=1.487). Moreover,the higher the rank of these hazard factors were increased,the more risk patients had to face.2.Enteral nutritional intervention analysis①Comparing to preoperation,weight loss of 29 patients with jejunostomy tube feeding was approximately 7.09±3.3Kg within 3-6month after gastrectomy,while tube-free group reached 9.87±3.1Kg,the difference was significant,P=0.020.②Ratio of NRS 2002≥3 was decreased in jejunostomy tube feeding group within 3-6 month since postgastrectomy,while increased in tube-free group,and differences were statistically significant,P=0.000.③Ratio of KPS-enhancing was found increasing in jejunostomy tube feeding group more significantly than that in tube-free group,P=0.0003.[Conclusion]1.Our study showed that postoperative survival rate in our unit was basically coincidence with what the foreign or domestic literatures reported.2.There were many hazard factors affecting postoperative patients' prognosis,including age(P=0.043),lymphadectomy(P=0.000),blood loss(P=0.025),blood transfusion (P=0.000),location of tumor,tumor size,tumor differential,lymphonode metastasis, tumor stage(P=0.000)3.Perioperative nutritional intervention and short term of enteral nutrition would decrease body weight loss due to cancer,operation stress and chemotherapy,and simultaneously ameliorate risk of malnutrition and enhance chemotherapeutic tolerance.