Aim To establish human U87-MG glioma model in nude mice brain and to observe the characteristics of the tumor growth. Methods Human U87-MG glioma cells were cultured in vitro. 5 μL of cell suspension containing 3.0 ×1010·L-1, 4.0×1010·L-1and 5.0×1010·L-1respectively was inocula-ted into the right caudate nucleus of 18 male nude mice brain un-der the guidance of stereotaxic apparatus, separately, whereas another 6 nude mice as the control group, were inoculated into the same volume of Hanks solution. The moving and survival state of rats with gliomas were observed. The examinations of the tumors formation, volumes, metastasis and histopathology were performed and the obtained brain samples were stained with HE and immunohistochemistry. Results All the tested rats of dif-ferent inoculation doses developed brain tumors without extracra-nial metastasis. The mean survival time of three groups was (46.50 ± 3.27) d,(38.50 ± 3.28) d and (30.67 ± 3.51) d,respectively. The tumors showed the similar morphological fea-tures and immunophenotype to human glioma. There was positive expression of GFAP and S-100 in the tumors. Conclusions The orthotopic implantation model of human U87-MG glioma, by in-oculating quantitative U87-MG cells stereotaxically into the brains of the nude mice, is successfully established with 100 yield of intracranial tumor and no extracranial growth extension. It resembles the histopathological and morphological features of human glioma,which can be used as a reliable animal model for the study of the tumorigenesis, pathogenesis, biological charac-teristics and therapy of glioma.

Carboxylesterase 1 (CE1) is an important serine hydrolase in mammals, which involved in the hydrolysis of a variety of compounds (endogenous substrates like cholesterol and xenobiotic compounds like ester-contain drugs and pesticides). This study aimed to design and develop the fluorescent probe substrates for human carboxylesterase 1 (hCE1), on the basis of the structural features of hCE1 preferred substrates. Four carboxylic esters deriving from BODIPY-8-carboxylic acid were designed and synthesized. After then, reaction phenotyping assays and chemical inhibition assays were used to evaluate the selectivity of these four ester derivatives towards hCE1. Our results clearly demonstrated that the substrate specificity of these ester substrates towards hCE1 would be improved with the decrease of the alcohol group on BODIPY-8-carboxylesters, while BODIPY-8-carboxylesters with small alcohol groups including methyl (BCM) and ethyl (BCE) esters could serve as the ideal probe substrates for hCE1. Given that BCM exhibit rapid hydrolytic rate in hCE1, we further investigate the enzymatic kinetics of this fluorescent probe substrate in both human liver microsomes (HLM) and recombinant hCE1, as well as to explore its potential application in high-throughput screening of hCE1 inhibitors by using HLM as enzyme source. The results showed that the kinetic behaviors and the affinity of BCM in HLM is much closed to those in recombinant hCE1, implying that hCE1 played the key roles in BCM hydrolysis in HLM. Furthermore, the inhibition study demonstrated that BCM could be used for rapid screening and characterization of hCE1 inhibitors, by using HLM to replace recombinant hCE1 as enzyme source.