MiR-145 functions as a tumor suppressor via regulating angiopoietin-2 in pancreatic cancer cells.

BACKGROUND: Pancreatic cancer is currently one of the leading causes of cancer deaths without any effective therapies. Mir-145 has been found to be tumor-suppressive in various types of cancers. The aim of this study is to investigate the role of miR-145 in pancreatic cancer cells and explore its underlying mechanism. METHODS: Quantitative real time PCR was used to determine the expression level of miR-145 and angiopoietin-2 (Ang-2) mNRA, and the expression level of Ang-2 protein was measured by western blotting. The anti-cancer activities of miR-145 were tested both in in vitro by using cell invasion and colony formation assay and in vivo by using xenograft assay. The direct action of miR-145 on Ang-2 was predicted by TargetScan and confirmed by luciferase report assay. The vascularization of xenografts were performed by immunohistochemical analysis. RESULTS: The expression level of miR-145 was significantly lower and the expression levels of Ang-2 mRNA and protein was significantly higher in the more aggressive pancreatic cancer cells (MiaPaCa-2 and Panc-1) when compared to that in BxPC3 cells. Overexpression of miR-145 in the BxPC3, MiaPaCa-2 and Panc-1 cells suppressed the cell invasion and colony formation ability, and the expression level of Ang-2 protein in MiaPaCa-2 and Panc-1 cells was also suppressed after pre-miR-145 transfection. Intratumoral delivery of miR-145 inhibited the growth of pancreatic cancer xenografts and angiogenesis in vivo, and also suppressed the expression level of angiopoietin-2 protein. Luciferase report assay showed that Ang-2 is a direct target of miR-145, and down-regulation of angiopoietin-2 by treatment with Ang-2 siRNA in the BxPC3, MiaPaCa-2 and Panc-1 cells suppressed cell invasion and colony formation ability. The reverse transcription PCR results also showed that Tie1 and Tie2 were expressed in BxPC3, MiaPaCa-2 and Panc-1 cells. CONCLUSION: MiR-145 functions as a tumor suppressor in pancreatic cancer cells by targeting Ang-2 for translation repression and thus suppresses pancreatic cancer cell invasion and growth, which suggests that restoring of miR-145 may be a potential therapeutic target for pancreatic cancer.

[The expression of peripheral Th1 and Th17 cells in inflammatory bowel disease and its potential clinical value].

OBJECTIVE: To explore the probable role of Th1 and Th17 cells in the pathogenesis of inflammatory bowel disease (IBD). METHODS: The peripheral blood mononuclear cells (PBMCs) from peripheral blood specimens were collected in the study, including 40 healthy controls, 42 ulcerative colitis (UC) and 39 Crohn's disease (CD). The proportion of Th1 and Th17 cells in the PBMCs was detected with flow cytometry after stimulated by PMA and ionomycin. The result and the clinical data were analyzed. RESULT: The Th1 cell expression was increased in CD (38.32 ± 16.18)% and UC group (34.23 ± 11.60)%, compared with the controls (24.58 ± 10.02)% (P < 0.01). During the convalescence, the Th1 expression in the CD and UC groups in vivo was significantly reduced without difference between the two groups (P > 0.05) . In the IBD group , significant difference in the frequency of Th17 cells could be found between the CD group (2.51 ± 1.59)% and the UC group (4.15 ± 2.75)%, while the Th17 cells were increased in both groups, compared with the controls (1.44 ± 0.73)% (P < 0.05) . Obvious difference in the frequency of Th17 cells could be found between patients at different activity stages and remission stages. The proportion of Th17 cells were higher in the UC patients than that in the CD patients (P < 0.01) . The Th17/Th1 ratio of CD patients, UC patients were 0.08 ± 0.06, 0.14 ± 0.11, which were both higher that in the controls (0.07 ± 0.06). Significant difference could be found between the UC group and the CD group (P < 0.01). CONCLUSIONS: The higher proportion of Th1 and Th17 cells are detected in the peripheral blood of IBD patients, which is correlated closely to the activity of the disease. Th1 and Th17 cells may play an important role in the pathogenesis of IBD.

Genetic polymorphism of MCP-1-2518, IL-8-251 and susceptibility to acute pancreatitis: a pilot study in population of Suzhou, China.

AIM: To study the relationship between MCP-1-2518A/G, IL-8-251A/T polymorphism and acute pancreatitis (AP) in the Han population of Suzhou, China. METHODS: A case-control study was conducted to compare the distribution of genotype and genetic frequency of MCP-1-2518A/G, IL-8-251A/T gene polymorphism among AP (n = 101), including mild AP (n = 78) and severe AP (n = 23) and control healthy individuals (n = 120) with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, and analyze the relationship between the MCP-1-2518A/G, IL-8-251A/T gene polymorphism and the susceptibility to AP. RESULTS: Significant differences were found in the distribution of genotype of MCP-1-2518A/G between the healthy control group and mild AP group (chi2 = 32.015, P < 0.001), the same was evident between the healthy control group and severe AP group (chi2 = 12.932, P < 0.05) in Suzhou. However, no difference of genotypic distribution was noted between MAP and SAP (chi2 = 0.006, P = 0.997). The genetic frequencies of G allele in mild AP were 72.4% (113/156) and 76.1% (35/46) in severe AP, both were higher than the controls, 47.1% (113/240) (chi2 = 24.804; P < 0.001, and chi2 = 13.005; P < 0.001), but no difference was found between severe AP and mild AP (chi2 = 0.242; P = 0.623). No difference was found in the distribution of genotype of IL-8-251A/T between the healthy control group and AP group neither in the frequency of A and T allele. CONCLUSION: The MCP-1-2518 AA genotype of the population in Suzhou may be a protective genotype of AP, while one with higher frequency of G allele is more likely to suffer from pancreatitis. But the genotype of AA and the frequency of G allele could not predict the risk of severe AP. No correlation is found between the IL-8-251 polymorphism and the liability of AP.

[Relationship between genetic polymorphism of MCP-1 and acute pancreatitis in Han population of Suzhou in China].

OBJECTIVE: To study the relationship between monocyte chemoattractant protein-1 gene (MCP-1) -2518A/G polymorphism and acute pancreatitis (AP) in the Han population of Suzhou, China. METHODS: The polymorphisms were detected with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The genotypes and allele frequencies of MCP-1 -2518A/G were calculated and analyzed in 101 AP patients including 78 mild AP (MAP) patients and 23 severe AP (SAP) patients, and 120 healthy individuals as control group. RESULTS: The frequency of MCP-1 -2518 AA genotype in control group was significantly higher than that in SAP and MAP groups (P < 0.01). People with AG and GG genotypes had 5.896 times risk of developing MAP (P < 0.01, OR=5.896) compared with people with AA genotype. Subjects carrying G allele were at a 7-fold elevated risk for SAP (P < 0.05, OR=7.011) contrasted with subjects carrying AA genotype. However, no difference in AA genotypic distribution was noted between MAP and SAP groups (chi square=0.006, P=0.997). The frequency of G allele in healthy controls was obviously lower than that in MAP (P < 0.01, OR=0.318) and SAP groups (P < 0.01, OR=0.309). No difference of G allele frequency was found between SAP group and MAP group (P=0.623, OR=1.211). CONCLUSION: The MCP-1 -2518 AA genotype of the population in Suzhou may be a protective genotype of AP. People with higher frequency of G allele is more likely to suffer from AP. Nonetheless, the genotype of AA and the frequency of G allele couldn't predict the risk of SAP.