Role and mechanism of gastric cancer stem cells in gastric cancer invasion, metastasis and angiogenesis / 中国组织工程研究

BACKGROUND:Although tumor stem cel s and their differentiated vascular cel s, which are not sensitive to chemotherapy and molecular targeted therapy, reduce overal blood supply of the tumor, these cel s facilitate the invasion and metastasis of the tumor, eventual y resulting in treatment failure. OBJECTIVE:To investigate the effect of gastric cancer stem cel s in stomach cancer invasion and metastasis as wel as its mechanism in angiogenesis. METHODS:A total of 20 gastric cancer stem cel s and 20 normal gastric cancer cel s SGC7901 were cultured in the medium with DMEM/F12 (1:1), 2%B27 and 20μg/L epidermal growth factors or cultured in 10%PBS, respectively. Invasion of gastric cancer stem cel s was detected by sphere formation assay, colony formation assay and Transwel invasion assay. Levels of mRNA and protein expression of CD44 and E-cadherin were measured to observe tumor metastasis. Besides, angiogenesis was observed by cel scratch test, Transwel migration assay and ring test. RESULTS AND CONCLUSION:Gastric cancer cel s adhered to the medium wal , and gastric cancer stem cel s suspended in the medium, which appeared to be spindle interstitial form. Number of gastric cancer tumor spheres was significantly lower than that of gastric cancer stem cel spheres in the sphere formation assay and colony formation assay (P<0.05). Number of gastric cancer stem cel s through the basement membrane was significantly higher than that of gastric cancer cel s (P<0.05). And the cel migration distance and ring number were significantly increased in the gastric cancer stem cel s as compared with the gastric cancer cel s (P<0.05). In conclusion, the invasion, migration and angiogenesis abilities of gastric cancer stem cel s are stronger than those of gastric cancer cel s, which can further promote the occurrence and progression of gastric cancer.

Establishment and comparison of stoma and stoma-free heterotopic small intestine transplantation models in mice / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To establish stoma and stoma-free murine models of heterotopic small intestine transplantation in order to choose a more effective and reliable model.</p><p><b>METHODS</b>A total of 140 male 8-10 weeks age C57BL/6(B6) mice weighted 25-30 g were enrolled in the experiment. Syngeneic heterotopic small intestine transplantation was performed between C57BL/6 mice, and recipient mice were divided into either stoma or stoma-free group. Heterotopic small intestine transplantation was performed in 70 mice, with 35 mice in each group. After closing the proximal end of the graft by ligation, the distal end of graft was exteriorized as a stoma then secured to the skin of the abdominal wall in stoma group. In stoma-free group, the distal end of graft was anastomosed end-to-side to the recipient ileum. Successful rate of operation, two-week survival rate, operation time, associated complications, postoperative care time and body weight change were recorded and compared between two groups.</p><p><b>RESULTS</b>The successful rate of stoma group was 65.7%, while it was 80.0% of stoma-free group (χ(2)=1.806, P=0.179). The operation time of donor in stoma group was (48.1±6.6) minutes, while it was (47.2±5.9) minutes in stoma-free group (t=0.598, P=0.552). The operation time of recipient in stoma group was (77.9±9.1) minutes, while it was (76.4±8.3) minutes in stoma-free group (t=0.683, P=0.497). The cold ischemic time of graft in stoma group was (34.7±4.0) minutes, while it was (33.9±4.6) minutes in stoma-free group(t=0.667, P=0.507). The two-week survival rate of stoma group was 45.7%, and it was 77.1% of stoma-free group(χ(2)=7.295, P=0.007). The stoma group had more complications[54.3%(19/35) vs. 22.9%(8/35), χ(2)=7.295, P=0.007], which needed more postoperative care time(191 min vs. 35 min). The weight loss in stoma group in the third day after operation was more significant [(81.52±5.20)% vs. (85.46±4.65)%, t=2.856, P=0.006]. By 2 weeks after operation, the weight of mice in both groups retruned to 95% of the postoperative wight.</p><p><b>CONCLUSION</b>The murine heteropotic small intestine transplantation model with stoma-free appears to be more reasonable and reliable.</p>

Effects of Local Pancreatic Renin-Angiotensin System on the Microcirculation of Rat with Severe Acute Pancreatitis

Severe acute pancreatitis (SAP) is normally related to multiorgan dysfunction and local complications. Studies have found that local pancreatic renin-angiotensin system (RAS) was significantly upregulated in drug-induced SAP. The present study aimed to investigate the effects of angiotensin II receptors inhibitor valsartan on dual role of RAS in SAP in a rat model and to elucidate the underlying mechanisms. 3.8% sodium taurocholate (1 ml/kg) was injected to the pancreatic capsule in order for pancreatitis induction. Rats in the sham group were injected with normal saline in identical locations. We also investigated the regulation of experimentally induced SAP on local RAS expression in the pancreas through determination of the activities of serum amylase, lipase and myeloperoxidase, histological and biochemical analysis, radioimmunoassay, fluorescence quantitative PCR and Western blot analysis. The results indicated that valsartan could effectively suppress the local RAS to protect against experimental acute pancreatitis through inhibition of microcirculation disturbances and inflammation. The results suggest that pancreatic RAS plays a critical role in the regulation of pancreatic functions and demonstrates application potential as AT1 receptor antagonists. Moreover, other RAS inhibitors could be a new therapeutic target in acute pancreatitis.

Activity of CDK1 in S phase cell checkpoint / 肿瘤研究与临床

Objective To investigate the phosphorylation and dephosphorylation of CDK1 based on the specific cell cycle apoptosis in Molt-4 cells and active variety of CDK1 in cell cycle specific apoptosis.Methods The exponential phase of growth Molt-4 cells (the human acute lymphoblastic leukemia cell line) were induced with dose response and time course of Camptothecin (CPT).The specific cell cycle apoptosis was detected with API method,then cell apoptosis was verified with post sorting confocal method.Meanwhile,the phosphorylation and dephosphorylation of CDK1 were detected by the protein electrophoretic analysis (Western blot).Results The specific cell cycle apoptosis occurred on exponential phase of growth Molt-4 cells after CPT treatment.When Molt-4 cells occured S-phase apoptosis, the apoptosis cell phosphorylation of CDK1-Thr161 band was more narrow than that of control cells, the apoptosis cell phosphorylation of CDK1-Thr15 band almost had the same band with control cells.Conclusion Cell apoptosis frequently developed in different cell cycle phase. API assay is quick and efficient method to analyze specific cell cycle apoptosis. When cell apoptosis take place in S-phase,the phosphorylation activity of CDK1 is inhibited.

Investigation on correlation between serum hypersensitivity-CRP and β-cell function in patients with gestational diabetes mellitus / 中国基层医药

Objective To explore the correlation between serum hs-CRP and β-cell finction in patients with gestational diabetes mellitus(GDM).Methods The levels of hs-CRP in 60 patients with GDM(GDM group)and 30pregnant women with normal glucose tolerance(NGT group)were detected.Insulin resistance was assessed by the homeostasismodel insulin resistance index(HOMA-IR),Insulin secretion by the homeostasis β-cell funetiOn index(HOMA-β).Results The levels of hs-CRP and HOMA-IR were higher in GDM group than in NGT group.There was significant difference between two groups(P＜0.01);HOMA-β was lower in GDM group than in NGT group,there was significant difference between two groups(P＜0.05).The level of hs-CRP was correlated with age,pre-pregnant bodymass-index(BMI),screening BMI,fasting blood glucose(FBG),fasting insulin(Fins),and HOMA-IR(r=0.222,0.649、0.862、0.923、0.935、0.941,P＜0.05 or P＜0.01),but was inversely related with HOMA-β(r=-0.872,P＜0.01).Multiple stepwise regression analysis indicated that HOMA-IR and HOMA-β was the most important effect factors of hs-CRP.Conclusion The level of hs-CRP increased in women with GDM.which was related to insulin resistance(IR)and insulin secretion,and it maybe participate in the pathogenesis of GDM.

Empirical study on the apoptosis of gastric cancer cells induced by taxol / 肿瘤研究与临床

Objective To investigate apoptosis of gastric cancer cells induced by taxol,and its specific apoptotic cell cycle phase. Methods The apoptosis rate of gastric cancer cell line MKN-28 induced by taxol was detected with Sub-G1 method.The specific apoptotic cell cycle phase Was detected with API and PSC method.The sensitivity of 20 cases clinic gastric cancer specimens induced by taxol was detected with the method MTT.Results With the Sub-G1 method the MKN-28 cells were induced by 10 μg/ml taxol,after 10 h,the apoptosis rate reached its top apex;with the API method and the PSC method,the specific apoptosts took place in G_2/M phase;the chemotherapy sensitivity of 16 cases out of 20 cases clinic gastnc cancer specimens exceed 50%with the method MTT. Conclusion Taxol could induce gastric cancer cells to aimptosis and the apoptosis takes place in G_2/M phase;Taxol is sensitive to clinic gastric cancer speclmens.

Dual effect of Molt-4 cell lines onset with Roscovitine / 肿瘤研究与临床

Objective To investigate the effect of Mlot-4 cells onset with Roscovitine (ROSC)as some Cyclin-dependent kinases(CDK),inhibitor.Methods The logarithmic growth phase Molt-4 cells treated with ROSC at a final concentration ranging between 1～20 μmol/L and harvested in different time point,DNA assay of single cells by flow cytometry was used to detect the effect of cell cycle arrest and Annexin-V/FITC assay was used to detect the effect of cell apoptosis. Results It showed that ROSC exerted strong inhibitory effect on proliferation and cell cycle progression of Molt-4 Accumulation of G2/M arrested cells starting 6 h after onset of 10 μmol/L and 20 μmol/L ROSC;at the same time,the cell apoptosis of Molt-4 would be detected,According with the time and concentration changing,the cell apoptosis rate would rise.Conclusion It is concluded that Roscovitine(ROSC)as some Cyclin-dependent kinases(CDK),inhibitor,It has dual effects to Molt-4 cells,not only the effect of cell cycle arrest but also the effect of cell apoptosis.