Induction of apoptosis by arsenic trioxide and hydroxycamptothecin in gastric cancer cells in vitro

AIM To study the effects of arsenic trioxide andHCPT on different degrees of differentiated gastriccancer cells（SGC-7901,MKN-45,MKN-28）withrespect to both cytotoxicity and induction ofapoptosis in vitro.METHODS The cytotoxicity of As2O3 and HCPTon gastric cancer cells was determined by MTTassay.Morphologic changes of apoptosis ofgastric cancer cells were observed by lightmicroscopy and transmission electron microscopy.Apoptosis and cell cycle changes of gastric cancercells induced by HCPT and As2O3 were investigatedby TUNEL method and flow cytometry.RESULTS As2O3 and HCPT had remarkablecytotoxic effects on different degrees ofdifferentiated gastric cancer cells.The IC50ofAs2O3 on well differentiated gastric cancer cellMKN-28,moderately differentiated gastric cancercell SGC-7901,and poorly differentiated gastriccancer cell MKN-28 were 8.91 μmol/L,10.57μmol/L,and 11.65 μmol/L,respectively.The IC50of HCPT on MKN-28,SGC-7901,and MKN-45 were9.35 mg/L,10.21 mg/L,and 12.63 mg/Lrespectively after 48 h treatment.After 12 h ofexposure to both drugs,gastric cancer cellsexhibited morphologic features of apoptosis,including cell shrinkage,nuclear condensation, and formation of apoptotic bodies.A typicalsubdiploid peak before G0/G1 phase was observedby flow cytometry.The apoptotic rates of SGC-7901,MKN-45,and MKN-28 were 13.84%,22.52%,and 9.68%,respectively after 48 hexposure to 10 μmol/L As2O3.The apoptotic ratesof SGC-7901,MKN-45,and MKN-28 were 21.88%,12.35%,and 30.26%,respectively after 48 hexposure to 10 mg/L HCPT.The apoptotic indicewere 7%-15% as assessed by TUNEL method.The effect of As2O3 on SGC-7901 showedremarkable cell cycle specificity,which inducedcell death in G1 phase,and blocked G2/M phase.HCPT also showed a remarkable cell cyclespecificity,by inducing cell death and apoptosis inG1 phase and arrest of proliferation at S phase.CONCLUSION As2O3 and HCPT exhibitsignificant cytotoxicity on gastric cancer cells byinduction of apoptosis.As2O3 and HCPT mighthave a promising prospect in the treatment ofgastric cancer,which needs to be further studied.

A study of preoperative methionine-depleting parenteral nutrition plus chemotherapy in gastric cancer patients

AIM To investigate the interference ofmethionine.free parenteral nutrition plus 5-Fu（-MetTPN+5-Fu）in gastric cancer cell kineticsand the side effects of the regimen.METHODS Fifteen patients with advancedgastric cancer were randomly divided into twogroups,7 patients were given preoperatively aseven-day course of standard parenteralnutrition in combination with a five-day courseof chemotherapy（sTPN+5-Fu）,while the other8 patients were given methionine-deprivedparenteral nutrition and 5-Fu（-MetTPN+5-Fu）.Cell cycles of gastric cancer and normal mucosawere studied by flow cytometry（FCM）.Bloodsamples were taken to measure the serumprotein,methionine（Met）and cysteine（Cys）levels,and liver and kidney functions.RESULTS As compared with the resultsobtained before the treatment,the percentage ofG0/G1 tumor cells increased and that of S phasedecreased in the-MetTPN+5-Fu group,while thecontrary was observed in the sTPN+5-Fu group.Except that the ALT,AST and AKP levels wereslightly increased in a few cases receiving-MetTPN+5-Fu,all the other biochemicalparameters were within normal limits.Serum Cys level decreased slightly after the treatmentin both groups.Serum Met level of patientsreceiving sTPN+5-Fu was somewhat higher aftertreatment than that before treatment;however,no significant change occurred in the -MetTPN+5-Fu group,nor operative complications in bothgroups.CONCLUSION -MetTPN+5-Fu exerted asuppressive effect on cancer cell proliferation,probably through a double mechanism ofcreating a state of'Met starvation'adverse tothe tumor cell cycle,and by allowing 5-Fu to killspecifically cells in S phase.Preoperative short-term administration of -MetTPN+5-Fu had littleundesirable effect on host metabolism.

Seroepidemiology of Helicobacter pylori infection among asymptomatic Chinese children

INTRODUCTIONIncreasing data has demonstrated that Helicobacterpylori(H.pylori),a spiral gram negativebacterium,colonized in human stomach,can causetype B gastritis,is strongly associated withgastric and duodenal ulceration,and has beenimplicated in the causation of gastric carcinomaand mucosa-associated lymphoid tissue(MALT)lymphomas.It has been reported that there

Nitric oxide synthase distribution in esophageal mucosa and hemodynamic changes in rats with cirrhosis

AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cirrhosis was assessed by using NADPHdiaphorase (NADPH-d ) histochemical method.Concentration of NO in serum were measured byfluorometric assay. Mean arterial pressure(MAP), cardiac output (CO), cardiac index (CI),splanchnic vascular resistance (SVR ), andsplanchnic blood flow (SBF ) were alsodetermined using 5’CO-labeled microspheretechnique.RESULTS Intensity of NOS staining in theesophageal epithelium of cirrhotic rats wassignificantly stronger than that in controls.There was a NOS--positive staining area in theendothelia of esophageal submucosal vessels ofcirrhotic rats, but the NOS staining was negativein normal rats. NO concentration of serum incirrhotic rats were significantly higher incomparison with that of controls. Cirrhotic ratshad significantly lower MAP, SVR and higherSBF than those of the controls.CONCLUSION SPlanchnic hyperdynamiccirculatory state was observed in rats withcirrhosis. The endogenous NO may play animportant role in development of esophagealvarices and in changes of hemodynamics incirrhosis.

Can the rat donor liver tolerate prolonged warm ischemia?

The last two decades of the twentieth century have witnessed increasingly successful rates of liver transplantation. The number of liver transplantations has increased steadily while the number of organ donors has remained relatively constant. Thus a great disparity has developed between the demand and supply of donor organs and remains a major limiting factor for further expansion of liver transplantation. Although many procedures, such as split liver[1] , living-related transplantation[2] , and xenotransplantation[3], have been attempted clinically to overcome the shortage, it is hoped that livers harvested from non-heart-beating donors (NHBDs) would alleviatethe problem of organ shortage, which again becomes the focus of attention[4-9]. However, sensitivity of the liver to warm ischemia remains a major worry for use of theNHBDs. The aim of this animal study was to assess if murine liver could tolerate prolonged period of warm ischemia and to determine the optimum timing of intervention in the cadaver donor in order to preserve liver viability.

Cyclosporin A protects Balb/c mice from liver damage induced by superantigen SEB and D-GaIN

AIM To investigate the pathogenic effect ofSEB and D-GalN on liver and the protection ofcyclosporin A, the relationship between hepaticapoptosis and necrosis and the possiblemechanism of acute hepatic necrosis.METHODS After staphylococcal enterotoxin B(SEB ) mixed with D--galactosamine (D-GaiN )were injected intraperitoneally into Balb/c miceand those previously treated with cyclosporin A,blood samples were collected and livers wereisolated at 2, 6, 12 and 24 h. Patterns othepatocellular death were studiedmorphologically and biochemically, circulatingcytokines (TNF-a, IFN--y ) and mice mortalitywithin 24h was assessed.RESU’LTS The SEB could induce the typicalapoptotic changes of hepatocytes, the D-GaiNcould induce hepatocytes apoptosis anddegeneration at the same time, and the micehaving received the SEB + D-GaiN injectionsdeveloped apoptosis at 2 and 6 h, but after 12 hhepatocytes were characterized by severein jury, whereas all the examinations in thecyclosporin A treated mice were normal.CONCLUSION Hepatic cell apoptosis might berelated to necrosis, and massive hepatocyteapoptosis is likely the initiating step of acutehepatic necrosis in mice. The effects induced bySEB and D--GaiN on hepatocytes might bemediated by T cells, and could be prevented bycyclosporin A.