Structure-activity relationship of pyrazol-4-yl-pyridine derivatives and identification of a radiofluorinated probe for imaging the muscarinic acetylcholine receptor M4

There is an accumulating body of evidence implicating the muscarinic acetylcholine receptor 4 (M4) in schizophrenia and dementia with Lewy bodies, however, a clinically validated M4 positron emission tomography (PET) radioligand is currently lacking. As such, the aim of this study was to develop a suitable M4 PET ligand that allows the non-invasive visualization of M4 in the brain. Structure-activity relationship studies of pyrazol-4-yl-pyridine derivates led to the discovery of target compound 12 - a subtype-selective positive allosteric modulator (PAM). The radiofluorinated analogue, [18F] 12, was synthesized in 28 ± 10% radiochemical yield, >37 GBq/μmol and an excellent radiochemical purity >99%. Initial in vitro autoradiograms on rodent brain sections were performed in the absence of carbachol and showed moderate specificity as well as a low selectivity of [18F] 12 for the M4-rich striatum. However, in the presence of carbachol, a significant increase in tracer binding was observed in the rat striatum, which was reduced by >60% under blocking conditions, thus indicating that orthosteric ligand interaction is required for efficient binding of [18F] 12 to the allosteric site. Remarkably, however, the presence of carbachol was not required for high specific binding in the non-human primate (NHP) and human striatum, and did not further improve the specificity and selectivity of [18F] 12 in higher species. These results pointed towards significant species-differences and paved the way for a preliminary PET study in NHP, where peak brain uptake of [18F] 12 was found in the putamen and temporal cortex. In conclusion, we report on the identification and preclinical development of the first radiofluorinated M4 PET radioligand with promising attributes. The availability of a clinically validated M4 PET radioligand harbors potential to facilitate drug development and provide a useful diagnostic tool for non-invasive imaging.

Celecoxib inhibits proliferation, invasion and migration of human pancreatic cancer cell line PANC-1 in vitro / 基础医学与临床

Objective To investigate the effects of cyclooxygenase-2 inhibitor celecoxib on proliferation , invasion and migration of human pancreatic cancer cell line PANC-1 and then determine the optimal concentration of cele-coxib and the most suitable application time .Methods Human pancreatic cancer cell line PANC-1 was treated with diverse concentrations of celecoxib (20,60,100 μmol/L) for different durations (24,48,72 h).Cell prolifer-ation, invasion and migration capabilities were measured by MTT colorimetry , Transwell invasion assay , and scratch assay respectively .Results The proliferation capability of PANC-1 cell was reduced by celecoxib in a con-centration-and time-dependent manner ( P <0.05 ) .In addition , the invasion and migration capabilities were decreased by celecoxib in a concentration-dependent manner(P<0.01).Conclusions Celecoxib attenuates the proliferation of human pancreatic cancer cell line PANC-1 in a concentration-and time-dependent manner .Cele-coxib attenuates the invasion and migration in a concentration-dependent manner .

Expression and role of MMP-14 protein in invasion and metastasis of stomach carcinoma / 重庆医学

Objective To explore the expression of matrix metalloproteinase-14(MMP-14)protein in the human stomach carcinoma tissues and its correlation with carcinoma invasiveness and metastasis.Methods The MMP-14 protein expression was detected by immunohistochemistry in 59 cases of stomach carcinoma tissues (observation group)and 20 cases of normal stomach tissues (control group,the adjacent normal tissues from the tumor margin of 5 cm confirmed by pathology),and its correlation with the clinically pathological parameters was analyzed.The expression characteristics of MMP-14 among various TNM stages of stom-ach carcinoma were also analyzed.Results The positive rate of MMP-14 expression was 50.85%(30/59)in the observation group and 5.00% (1/20)in the control group,the positive rate of the observation group was significantly higher than that of the control group (P <0.01);the expression level of MMP-14 was correlated with the differentiation degree,regional lymph node metastasis degree,invasion depth,lymphatic invasion and TNM stage,which showing the statistical difference(P < 0.01);the expression of MMP-14 protein was up-regulated and showed the transferring trend from cytoplasm to cellular membrane along with the progres-sion of TNM stage.Conclusion The overexpression of MMP-14 protein exists in stomach carcinoma tissues,which contributing to the invasion and metastasis of stomach carcinoma cells.

The Anti-Tumor Effect and Mechanism of Curcumin in Pancreatic Cancer / 天津医药

Objective To investigate the anti-tumor effect and mechanism of curcumin in pancreatic cancer (PC). Methods Smad4 and Jab1 expressions were detected by immunohistochemistry in tumor tissues and pericarcinomatous tis?sue from 35 PC cases, and the correlation of Smad4 and Jab1 were analyzed based on the percentage of positive staining in?tissues from 21 random selected PC cases. The effect of curcumin on expressions of tumor suppressors p53, Smad4 and cell cycle inhibitor p27 were examined by Western Blotting after human pancreatic cancer cell line PANC-1 were divided into PANC-1 control group (no treatments were given) and PANC-1 curcumin group (treated with cell culture medium containing 10μmol/L curcumin). The effect of curcumin on expressions of combination of β-TrCP1 and Smad4 was examined by Co-Immunoprecipitation after human embryonic kidney cell line 293T were divided into 293T control group (no treatments were given), 293T curcumin group (treated with cell culture medium containing 10μmol/L curcumin) and 293T Jab1 group (trans?fected by HA-Jab1 plasmid). Results Compared with expressions in pericarcinomatous tissues, Smad4 was down regulated while the expression of Jab1 was upregulated in PC tissues (P<0.01), and the expression of Smad4 was negatively correlated with the expression of Jab1 (n=21, r=-0.71, P=0.007). After treated with curcumin, the protein expression of p53, Smad4 and p27 was increased in PANC1 cell, and the protein expression of the combination ofβ-TrCP1 and Smad4 was decreased in 293T cell (P<0.05). After transfected by HA-Jab1 plasmid, the protein expression of the combination ofβ-TrCP1 and Smad4 was increased in 293T cell (P<0.05). Conclusion Curcumin may have suppression effect of PC through increasing the protein expression of p53, Smad4 and p27, and the mechanism of Smad4 upregulation may be related with the inhibition of Smad4 ubiquitination process, while Jab1 may be also involved in Smad4 degradation through ubiquitination.