Clinical & Experimental Research Of Nutritional Support In Patients With Liver Cancer

BackgroundPrimary hepatic cancer(PHC) is one of the most common malignant tumors in our country.The morbidity of PHC has increased in recent years. According to the statistic of the Ministry of Health in 1995,the mortality of PHC is the second place in all the malignant tumors,and it threatened the health of residents in our country heavily.Nowadays,partial hepatoectomy is still the first choice and the most effective treatment in the patients with PHC.While because of trauma,influence on the metabolism and the internal environment,and the stress reaction,the patients received partial hepatoectomy are always found with malnutrition, delayed recovery,immune suppression.It was agreed that the Nutritional support can relieve the negative nitrogen balance,maintain the function of important organs,and reduce the complication of partial hepatectomy.It was disagreement that enteral or parenteral nutritional support postoperative was safe for patients with primary liver cancer.Some animal experiments studies showed that parenteral nutrition support could promote malignant cell growth.It was not in favor of malignant tumors with long-term preoperative nutritional support in patients in order to prevent promoting tumor proliferation and metastasis,especially in parenteral nutritional support at present. Compared with parenteral nutrition,enteral nutrition has the following advantages:①Nutrition substrates are absorbed from the intestinal,and go into the liver by portal vein,which is consistent with the physical and in favor of visceral protein synthesis and metabolism.②Enteral nutrition provides nutrients for the mucosal cells in order to maintain intestinal mucosal barrier and prevent bacteria ectopic.③Fatty acids absorbed in the intestinal can not be used by tumor cells.④Enteral nutrition can reduce complications of liver and gallbladder,et al. Moreover,compared with gastrointestinal,enteral nutritional support is a safer way for patients with partial hepatectomy because patients have gastrointestinal integrity.With re-recognition with the intestinal function,early enteral nutrition(EN) was paid much attention on in recent years.Early postoperative nutritional support means nutritional support is given in 6-24 hours postoperative.Some studies have shown that early postoperative nutritional support could improve the patient's nutritional status.Due to the concept of "anal exhaust before eating", trouble of implementation,and patients with abdominal distension, diarrhea and other symptoms during enteral nutritional support, application of early post-operative enteral nutritional supports in clinical has been restricted.Studies showed that small bowel function was retuned to normal in 6～12 h after surgery.Although it could not be fully restored,they could absorb enough nutrients of the body needs. Meanwhile,with the concept of immune nutrition,some nutrients with the tumor-growth inhibition were found recently.ω-3 Polyunsaturated Fatty Acid(PUFA) was one of the immune nutritional substrate found in recent years.It was mainly in the Deep Sea Fish Oil food,with anti-thrombosis, reducing blood fat,blood pressure,anti-arteriosclerosis,and inhibiting excessive inflammatory response.PUFA also could change the lipid composition on malignant cell membrane,thus change its fluidity, and enhance the sensitivity of all kinds of treatments.Epidemiological survey found thatω-3PUFA could inhibit the development and the occurrence of prostate cancer,breast cancer,and colorectal cancer.The inhibited effect ofω-3 PUFA on a variety of tumors and tumor cells was confirmed by cell culture experiments in vitro and animal experiments. Mechanisms of the effect of PUFA on tumor cells are not clear.There are the following hypotheses provided by relationship articles.(1) PUFAchanges the structure and function of biofilm and increases the generation of lipid peroxide.PUFA is important structural fatty acids of biofilm.Adding PUFA can change the composition of biofilm,and lead to changing function and the normal activity of cell membrane and mitochondrial membrane.Stoll,etc. found thatω-3/ω-6 PUFA increasing in tumor cell membrane could lead to cell membrane fluidity and permeability,cytotoxic drugs go easily through the cell membrane,and enhance the sensitivity of the tumor to chemotherapy.Chapkin,etc.found thatω-3/ω-6PUFA increasing in tumor mitochondrial membrane could lead mitochondrial membrane to decline, cellular respiration and electron transport chain damage,mitochondrial membrane PT(permeability transition) hole to open,membrane permeability, cytochrome C and apoptosis-inducing factor to release,cysteine protease (caspase) enzyme cascade can be carried out,at last lead to apoptosis.(2) PUFA causes cell dysbolism and promotes cell apoptosis or death The common features of tumor cells are strong metabolism,cell cycle regulation destruction and apoptosis reduction and suspension.Apoptosis plays an important role in tumor incidence and growth.There was evidence that promotion of apoptosis was also anti-tumor mechanism of PUFA.Most literatures have been reported that the inhibition mechanism of PUFA inhibition of tumor cell lines was different,such as prostate cancer, breast cancer,colorectal cancer,est.,but the common feature was apoptosis.(3) PUFA causes Lipid peroxidation metabolites and cytotoxicity Products of lipid peroxidation and free radicals have a killing effect on cells.Normal cells have a complete response to anti-oxidation system and should be exempted from peroxidation damage.Because of low content of antioxidant enzymes and the corresponding cell antioxidant barrier defects,tumor cells have low anti-lipid peroxidation ability.As accumulating products of lipid peroxidation and free radicals,tumor cells are vulnerable to peroxidation.ω-3 fatty acids are the major lipid peroxidation substrate in cells,who contains more unsaturated double bonds more be easily oxidized,resulting in excessive free radical oxidation products.These substances can damage tumor cell membrane and change the cell composition or assembly of the cytoskeleton and regulating membrane transport systems or enzymes,or PCR inhibition and or polyamine synthesis,and lead to cell death or apoptosis, signal transudation pathway change,cell growth inhibition.(4) PUFAinhibits biosynthesis of arachidonic acid source material type peanutArachidonic acid(hA) is the major cell membrane polyunsaturated fatty acids.Therefore,most of the categories of peanut acids are the source material 2 series prostaglandins(prostaglandins and thromboxane) and interleukin 4 series of leukotrienes,these substances have a strong pro-inflammatory and promote cell proliferation.Leahy KM and Cianchi F, et al.found that PGE2 could prevent tumor cell apoptosis and stimulate tumor cell proliferation and promote the role of tumor angiogenesis. Pidgeon GP,etc.found that product of 12-Lox effect on AA 12-HETE participated in cell cycle regulation,tumor angiogenesis and anti-apoptotic and adhesion expression of metastasis-related genes. Calder PC,etc.found that leukotriene B4(LTB4) had a related with tumor adhesion and increased the generation of reactive oxygen species and attacked DNA leading to cancer.Chen JK,etc.found that 14,15-epoxyeicosatrienoic acid which was c product of ytochrome P450 single-oxygenase effect on AA could inhibit cell apoptosis. (5) Changes of cancer-related gene expressionRecent studies found thatω-3 polyunsaturated fatty acids(PUFA) could control a variety of apoptosis-related genes,exert cytotoxicity to tumor cells and induce tumor cell apoptosis.There were more and more literatures about polyunsaturated fatty acids(PUFA) effect on tumor-associated gene expression.Clarke and Deckelbaum,etc.have summed up the related literatures,including transcription-related genes, oncogenes,tumor suppressor gene,with the proliferation of split-related genes,with the invasion and metastasis-related genes,and apoptosis-related genes,as well as the increasing trend.Articles of relationship betweenω-3 polyunsaturated fatty acids(PUFA) and bcl-2 family were majority.Some studies have shown that HL-60 cells and human breast cancer cell induced by EPA could occur apoptosis,and observed that bax,bcl-xs expression with the promotion of apoptosis significantly increased,bcl-2,bcl-x1 gene expression with the role of anti-apoptotic were significantly inhibited,indicating that EPA could regulate bcl-2 family expression of activity-induced tumor cell apoptosis.In addition, Bax could translocate from the cytoplasm to the mitochondrial outer membrane,under stimulated in the apoptotic signal,into a membrane protein,the formation of transit access,and promote the release of cytochrome C to accelerate the occurrence of induced apoptosis However,there were few reports on the effect ofω-3PUFA on liver cancer cells.Therefore,we will study the role of nutritional support on patients liver cancer in two ways.With the recognition of the function of GI tract,the early enteral nutrition was emphasized.However,there were no unified views about clinical value of the effect of early enteral nutrition on postoperative recovery in patients with partial hepatectomy.Moreover,there are few reports on the effect ofω-3PUFA on liver cancer cells.Therefore,we will study the role of nutritional support on patients liver cancer in two ways.1.The effect of early enteral nutrition on postoperative recovery in patients with partial hepatectomy.2.Mechanism and inhabited effects ofω-3 polyunsaturated fatty acid on the proliferation of hepatocellular carcinoma cells.PartⅠThe effect of early enteral nutrition on postoperative recovery in patients with partial hepatectomyObjectivesTo explore the effect of early enteral nutrition on postoperative recovery in patients with liver resection.Methods(1) 44 cases of liver resection were randomly divided into two groups to receive enteral or parenteral nutrition support for a week respectively.(2) The effect of two nutrition supports on nutrition and immune function, such as the basis of nutritional status,liver function,intestinal function,post-operative complications,lymphocytes and interleukin-2 (IL-2),were observed.Results(1) There was no significant difference between preoperative liver function with Child-Pugh classification(see Table 1,x~2=0.121,P=0.50) and the nutritional status of two groups of patients(P＞0.05).There was no significant difference between the scopes of liver resection of two groups of patients(x~2=1.126,P=0.771),which was comparability.(2) There was no significant difference between the heat(EN:7412±368Kj; PN:7149±421Kj) and nitrogen(EN:9±7g;PN:10±13g) which was given in two groups of patients everyday.(3) Intestinal function recovery time in enteral nutrition group of patients(59±14) h was shorter than that in parenteral nutrition group of patients(73±17) h(t=-2.960,P=0.005).(4) The body weight and the upper arm circumference decreased significantly after operation.Serum total protein,albumin and prealbumin decreased significantly after operation.(5) After a week of nutritional support,prealbumin could return to preoperative levels,but the total protein,albumin could not return to pre-operative level.(6)Serum triglycerides significant decreased after operation.After a week of nutritional support,serum triglycerides could return to preoperative levels in intravenous nutrition group,but it could not return to pre-operative level in enteral nutrition group.(7) Blood lymphocytes decreased significantly after operation in two groups.After a week of nutritional support,blood lymphocytes could restore to pre-operative level in EN group,but it could not restore to pre-operative level in PN group.(8) After a week of nutritional support,the level of serum IL-2 increased significantly(P＜0.05) in EN group,however,there was not significant change in the PN group.ConclusionsEarly nutrition support could reduce protein decomposition in patients with hepatectomy,and improve their nutritional status.So,it was helpful for recovery of patients received partial hepatectomy.Early EN also could significantly promote intestinal functional recovery in patients, compared with PN.EN could significantly promote the number of lymphocyte recovery and enhance the level of serum IL-2 after hepatectomy,which indicated that EN was better than PN in improving the patient's immune function.Therefore,early EN is a reliable,useful way of nutritional support after hepatectomy. PARTⅡInhibited ofω-3 polyunsaturated fatty acid on the proliferation of hepatocellular carcinoma cellsObjectivesTo explore inhibited ofω-3 polyunsaturated fatty acid on the proliferation and apoptosis of hepatocellular carcinoma cells.Methods(1) Appropriate concentration of logarithmic phase cells was selected by using MTT method and growth curve.(2) The effect of DHA and EPA on the growth of hepatocellular carcinoma HepG2 cells proliferation was measured by using MTT method.(3) The express of PCNA in hepatocellular carcinoma HepG2 cells were observed by Immunohistochemical method after incubated with DHAand EPA, respectively.(4) Cell shape changes of hepatocellular carcinoma HepG2 cells were observed by fluorescence staining after incubated with DHA and EPA, respectively.(5) Cell ultra structure changes of hepatocellular carcinoma HepG2 cells were observed by transmission electron microscopy after incubated with DHA and EPA,respectively.(6) Cell apoptosis of hepatocellular carcinoma HepG2 cells were detected by flow cytometry after incubated with DHA and EPA,respectively.Results(1) According to the curve of cells growth,a cell in concentration of 1×105 cells/mL was in logarithmic phase,which was selected for drug intervention trials.(2) MTT colorimetric showed that DHA inhibited the growth of HepG2 cells. With the increase in dosage and time,IR of cells growth increased significantly.There was statistically significant difference between each group(P＜0.05).The proliferation of HepG2 was inhabited significantly by DHA with a dosage-dependent and time-dependent manner.(3) MTT colorimetric showed that EPA inhibited the growth of HepG2 cells. With the increase in dosage and time,IR of cells growth increased significantly.There was statistically significant difference between each group(P＜O.05).The proliferation of HepG2 was also inhabited significantly by EPA with a dosage-dependent and time-dependent manner.(4) After incubated with DHA or EPA at two concentrations(45μg/mL and 60μg/mL) for 24 h,expression of PCNA in HepG2 cells decreased with the drug concentration increasing.(5) After incubated with DHA/EPA at concentration of 45μg/mL for 48 h respectively,fluorescence staining showed that the amount of HepG2 cells apparently reduced,cells shrinked,apoptotic bodies or nuclear debris appeared.(6) Compared with the control group cells,changes of vacuolization of mitochondria increasing,rough endoplasmic reticulum expansion and concentration of chromatin marginating appeared in HepG2 cells after incubated with PUFA.A large number of intracytoplasmic size electron-dense materials and apoptotic bodies could be seen.(7) After incubated with DHA/EPA at concentrations of 45μg/mL and 60μg/mL,flow cytometry showed apoptosis appeared in HepG2 cells. Compared with the control group,DHAand EPA could significantly promote HepG2 cells apoptosis(P＜0.05).Compared with the low concentration (45μg/mL),DHA and EPA at high concentration(60μg/mL) could promote HepG2 cells apoptosis(P＜0.05) obviously.ConclusionsThe proliferation of HepG2 was inhabited significantly by DHA/EPA with a dosage-dependent and time-dependent manner.DHA/EPA could lead HepG2 cell early apoptosis and death which were detected by using flow cytometry. HepG2 cells were destructed at last.Therefore,ω-3 polyunsaturated fatty acid could suppress the proliferation of nepG2 cells and induce apoptosis.