Multidrug resistance (MDR) is widely thought to be a major cause of the failure in cancer chemotherapy. The detection of MDR marker is therefore valuabe in studying the mechanisms of MDR and to predict response to chemotherapy in patient with carcinoma. Previous studies have examined MDR marker in gastric cancer, but the major part of the investigation in patients have focused on a single parameter. The purposes of this study were to detect the expression of glutathione S transferase pi(GST ?), multidrug resistance associated protein(MRP), lung resistance protein(LRP) and multidrug resistance gen 1 (MDR1) in the patients with primary gastric cancer, who had not received prior chemotherapy, and evaluate the correlation between GST ?, MRP, LRP and MDR1. The expression of GST ?, MRP, LRP and MDR1 mRNA in carcinoma tissue and the adjacent non cancerous tissue from 50 patients was examined by semiquantitative reverse transcription polymerase chain reaction (RT PCR). The positive rate of GST ? mRNA, MRP mRNA, LRP mRNA and MDR1 mRNA in gastric cancer tissue were 36.00%, 12.00%, 10.00%, and 10.00% respectively. Their expression in gastric cancer tissue was significantly higher than that in the adjacent non cancerous tissue. The overall positive rate of their expression in gastric tissue was 48.00%. The results indicated that GST ? mRNA, MRP mRNA, LRP mRNA and MDR1 mRNA are overexpressed in various degrees and no co expression exists among the studied genes in gastric cancer,and perhaps intrinsic MDR exists in 46% patients with primary gastric cancer .

Objective To investigate the retardation effect of voltage gated potassium channel Kv1 5 on growth of gastric cancer cells SGC7901. Methods By using restriction enzymes of Hind Ⅲ and Kpn I, cDNA encoding Kv1 5 was reversely constructed into eukaryotic expression vector pcDNA3 1. SGC7901 cells were transfected with the recombinants using LipofectAMINE2000. Stable clones of transfectants were obtained after selection by G418 The growth of cells was monitored by cell growth curve and cell colony formation. The effect of Kv1 5 protein on cell cycle was examined by flow cytometry. Expression of Cyclin D1 protein was detected by Western blot. Results The antisense was found to effectively inhibit the expression of Kv1 5 protein in the transfectants. The growth and colony formation of transfectants were significantly reduced as compared with controls. The cell cycle review showed retardation of transfectants with Kv1 5 antisense in the G 1 phase. Expression of Cyclin D1 protein was decreased in Kv1 5 antisense transfectants. Conclusion The antisense of Kv1 5 has effect of retardation on growth of gastric cancer cells SGC7901

Objective　To investigate the effect of a new cloned full length gene, C2 gene which encodes a translation initiation factor, on cell cycle and the relationship between C2gene and apoptosis. Methods　Construct a eukaryotic vector carrying the full length of C2 gene, then transfected it into a gastric cell line-SGC7901 cells and gained cells expressing C2 protein transiently or stably. Test the expression of C2 protein and the change of cell cycle of the transfected cells using the flurescence activatied cell sorting(FACS) and the changes of their ultra structure electromicroscopically. Results　The C2 gene eukaryotic expression vector was successfully constructed. FACS showed the C2 protein expression ratio of transfected cells was 32.3%, while the empty control group was 0.9%. The test of cell cycle showed that there was appeared apoptosis peak in transiently or stably transfected cells. The apoptosis cells can be seen electromicroscopically among the C2 transfected cells. Conclusions　C2 gene transfection can lead SGC7901 cells to apoptosis, but the mechanism has to be further study.

Objective To investigate the clinical characteristic,diagnosis and treatment of familial adenomatous polyposis (FAP).Methods According to family history of the proband,we surveyed the pedigree and retrospectively analyzed the clinical characteristics of 10 FAP patients in 3 generations of the family.Result Among all 10 cases,3 died of colorectal cancer including two of whom had history of intestinal obstruction.Seven people of the third generation were all diagnosed as FAP.Among them,only 2 patients had clinical symptoms.Colonoscopy was done in all 7 patients before 35 years old.However,none of them had polyps or evidence of cancer.Surgical operation was performed on 1 patient and high frequency electric cutting under endoscopy was performed on 6 patients.Conclusions The early clinical manifestations of FAP are nonspecific.Pedigree investigation and colonoscopy screening for high-risk population are important to find early asymptomatic FAP patients.

Objective To evaluate the expression of KAII (CD82) gene inhibited by small interfering RNA (siRNA) in human pancreatic cancer cell line T3. Methods Four sequences of siRNA including A, B,C, D were designed, which were based on the KAI1 gene sequence using online RNA interfering designing software and lentivirus vector was built. Then they were used to transfect T3 cells by liposome 2000 and virus titer was determined. Empty vector containing siRNAd1 lentivrus particle ( MOI =5) was also used to infect T3 cells. The expression of CD82 mRNA was detected by real-time PCR. Results The expression of CD82 mRNA in normal control group, empty vector group, A group, B group, C group, D group were 1. 398 ±0.242,1. 311±0.048, 0. 664 + 0. 093, 0. 345 ± 0. 032, 0. 641 ± 0. 049 and 0. 147 ± 0. 049, respectively, the difference between the expression of CD82 mRNA in empty vector group and that of A, B, C, D groups was significant (P＜0.01 ). Conclusions RNAi was able to inhibit the expression of KAI1 gene CD82 in human pancreatic cancer cell line T3.

Objective To investigate the currents impact on delayed rectifier potassium (HERG)regulated by cyclooxygenase (COX)-2 in gastric cancer cells and its mechnism. Methods ① The HERG mRNA, protein and current in gastric cancer cells transfected with or without COX-2 antisense vector were measured by RT-PCR, Western blot and patch-clamp, respectively. ② cAMP concentration in gastric cancer cells transfected with or without COX-2 antisense vector was measured by ELISA. ③ The mutant HERG, which was absence of cAMP-binding domain, was constructed by PCR and transfected into gastric cancer cells. ④ The impact of COX-2 inhibitor and proglandin (PG) E2 on HERG current in gastric cancer cells transfected with or without mutant HERG was investigated by patch clamp. ⑤ The effects of agonist and antagonist of cAMP and inhibitor of protein kinase (PK) A on HERG current in gastric cancer cells transfected with or without HERG mutant were observed by patch clamp. Results ① The expression of HERG mRNA and protein in gastric cancer cells transfected with COX-2 antisense vector were not altered, but the amplitude of HERG current was diminished (P<0.05). ② The cAMP concentration in gastric cancer cells transfected with COX-2 antisense vector was lower than that in parental gastric cancer cells (P<0.05). ③ COX-2 inhibitor and PGE2 had influence on the HERG currents in gastric cancer cells. COX-2 inhibitor reduced and PGE2 enhanced the amplitude of HERG current in gastric cancer cells. However, neither COX-2 inhibitor nor PGE2 showed any negative or positive effects on currents of mutant HERG. ④ cAMP agonist enhanced the amplitude of HERG current and cAMP antagonist reduced the amplitude in gastric cancer cells. Neither agonist nor antagonist had effect on currents of mutant HERG. ⑤ PKA inhibitor did not influence the HERG current of parental gastric cancer cells and gastric cancer cells transfected with mutant. Conclusions COX-2 regulates HERG current through its catalytic product of PGE2, which binds with its receptor on the gastric cancer cells and alters cAMP level in gastric cancer cells, cAMP interacts with HERG protein by binding with cAMP-binding domain of HERG protein and exerts impact on HERG current. PKA does not participate in this process.

Objective To explore a highly sensitive and highly specific method to detect the serum MG7 antigen (Ag) level for early gastric cancer diagnosis.Methods The serum MG7-Ag level was detected by enzyme-linked immunosorbent assay (ELISA) method in 116 preoperative gastric cancer patients,63 postoperative gastric cancer patients,41 patients with precancerous lesion,37 patients with precancerous diseases,50 healthy individuals and 281 patients with other cancers.Meanwhile,the expression of MG7-Ag was also examined with immunohistochemistry in patients with gastric cancer or precancerous lesion.Chi-square test was used for comparing positive rates of the two detection methods.Results The positive rate of MG7-Ag determined by ELISA was 83.6％(97/116) of preoperative gastric cancer patients,45.2％(28/62) of lung cancer patients,45.5％(20/44) of rectal cancer patients,17.6％ (12/68) of colonic cancer patients,14.2％ (6/42) of breast cancer patients,47.6％ (30/63) of postoperative gastric cancer patients,19.5 ％ (8/4 1) of patients with precancerous lesions,5.4 ％ (2/37) of patients with precancerous diseases and 0 of healthy individuals.The sensitivity of ELISA (83.6 ％) was similar with that of immunohistochemistry (94.0％)(P＞0.05).However,the false positive rate of ELISA (12.8 ％) was lower than that of immunohistochemistry (51.3 ％) (x2 =26.491,P＜0.01).There was statistically significant difference in MG7 Ag expression in gastric cancer with different clinical stages (x2=15.564,P＜0.01).Conclusion This ELISA method might be a non-invasive screening method for population with high risk of gastric cancer.

Objective: To construct eukaryotic expression vector of adenovirus type 5 fiber gene and investigate its expression in eukaryotic cell. Methods: By endonuclease digestion, fragment harboring the fiber gene was cloned into plasmid pBluescript M13- from the pAdEasy-1 to construct pBS/Fiber. The pBS/Fiber was then digested with XbaI and KpnI. The yielding fragment was subcloned into the pcDNA3.1, obtaining the eukaryotic expression vector pcDNA/Fiber. To test the eukaryotic expression ability of the pcDNA/Fiber, pcDNA/Fiber was transiently transduced into the COS-7 cells using lipofectamine, and the fiber protein was detected by SDS-PAGE and Western blot. Results: Both plasmid pcDNA3 1 and eukaryotic expression vector pcDNA/Fiber were successfully constructed. Anew protein band was detected by SDS-PAGE and Western blot, its molecular weight was 62 kD on denaturing SDS-PAGE gel and 186 kD on non-denaturing SDS-PAGE gel.Conclusions: The eukaryotic expression vector of the adenovirus type 5 fiber gene was expressed in the COS-7 cells. In natural state, the expressed fiber protein was a trimer. The plasmid pBS/Fiber can be used to construct target adenovirus vector.

Objective To synthesize H.pylori bacterial ghosts (BG) and loaded with adriamycin.The cytotoxic effects in gastric cancer cell line were also observed.MethodsThe lysis plasmid was introduced into H.pylori by bacterial conjugation. H.pylori BG were produced by inducing H.pylori lysis at 42 ℃.After suspension and centrifuge, H.pylori BG were loaded with adriamycin.The adriamycin loading quantity was measured with spectrophotometry.The cytotoxic effects of H.pylori BG-adriamycin in gastric cancer cell line SGC7901 were evaluated with MTT assay.ResultsH.pylori BG were successfully synthesized and loaded with adriamycin.The loading quantity of adriamycin was 70.4 μg/mg.H.pylori BG were seen to be adsorbed and internalized by gastric cancer cells under confocal microscope, which distributed on the surface or cytoplasmic of SGC7901 cell line. Carried Adriamycin was delivered into gastric cancer cell line and mainly accumulated in the nucleus.IC50 of SGC7901 to H.pylori BG-adriamycin was 0.32 ± 0.15 by MTT assay, which was significantly lower than that to free adriamycin (0.44 ±0.15, P＜0.05).Conclusions The proliferation of gastric cancer cells were effectively inhibited by H.pylori BG-adriamycin.H.pylori BG are expected to be ideal carrier for anti-gastric cancer medicine.

Objective To evaluate the therapeutic efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) for the treatment of portal hypertension of patients with hepatocellular carcinoma.Methods Ninety-five portal hypertension patients with hepatic carcinoma were enrolled.TIPS was performed in 63 patients and the other 32 patients received support medical care.The data referred to survival time of the 95 patients after treatment was collected by follow-up visit.The informations about success rate of TIPS,hepatic encephalopathy,rebleeding and causes of death were assessed.The Kaplan-Meier method was used to compare the survival time between two groups.The association of survival time with Child-Pugh classification and model for end-stage liver disease (MELD) score was analyzed.Results The success rate of TIPS was 97.8% with reduction of mean portal vein pressure of 13.6 cmH2O(1 cmH2O=0.098 kPa).The incidence of hepatic encephalopathy was 20.6% and rebleeding was 26.3% six months after TIPS treatment.Fifty-six patients treated with TIPS died at the end of follow-up.Twelve of which were died of variceal bleeding complicated with portal hypertension.The median survival time of TIPS group (3.67 months) was significantly longer than that of control group (1 month). Moreover, the median survival time in patients with low MELD score (≤13) was significantly longer than that in those with high MELD seore (＞13, x2=4.71,P=0.03). Whereas the median survival time was decreasing from Child-Pugh A to C(x2=15.6,P=0.00). Conclusions TIPS is one of effective and safe therapeutic methods to control portal hypertension. However, liver function is an important factor for selcetion of TIPS.