A Zn-modified PCN-224 fluorescent nanoprobe for selective and sensitive turn-on detection of glutathione.

Monitoring endogenous glutathione (GSH) levels in living cells is essential for cancer diagnose and treatment. In this work, GSH responsive fluorescent nanoprobe with turn-on property was constructed using Zn-modified porphyrinic metal-organic frameworks (PCN-224-Zn). The introduced Zn2+ could quench the fluorescence of PCN-224 by the metallization of organic ligand (TCPP) and serves as sensing site for GSH. When exposed to GSH, the strong binding affinity of GSH generates the formation of Zn-GSH complex, eliminating the fluorescence quenching effect of Zn2+. Based on the constructed PCN-224-Zn nanoprobe, selective determination of GSH was achieved in the range of 0.01-6 µM with a detection limit of 1.5 nM. Furthermore, the constructed nanoprobe can realize the fluorescence imaging of endogenous GSH in MCF-7 and HeLa cells. Meanwhile, PCN-224-Zn could also monitor GSH in cell lysate with recovery rates from 93.8 % to 102.3 %. The performance of PCN-224-Zn demonstrates its capacities in the application of fluorescence sensing and bio-imaging fields.

Study of correlation between expression of bradykinin B2 receptor and pathological grade in human gliomas.

In clinical practice there is a difference in response of the blood-tumour barrier (BTB) permeability induced by bradykinin in brain tumours with the same pathology. The variability in response of tumours to bradykinin is likely to be related to the expression level of bradykinin B(2) receptor. This study used fresh human glioma samples to determine the expression level of bradykinin B(2) receptor on gliomas with different pathological grades. The grade of tumour was classified using the WHO classification. To determine the bradykinin B(2) receptor expression level in gliomas, Immunohistochemistry and Western blot methods were used. In 24 cases of gliomas there were eight cases of WHO I glioma, eight cases of WHO II glioma and eight cases of WHO III glioma. Both Western blot and immunohistochemistry showed bradykinin B(2) receptors localized on tumour cells, whilst brain cells at the edge of the glioma hardly expressed B(2) receptor. There were significant differences of bradykinin B(2) receptor expression level among different pathological grades of glioma. The expression of B(2) receptor in the three grades of glioma was in the order of WHO I < WHO II < WHO III. Determination of bradykinin B(2) receptor expression level in human glioma may be useful in screening glioma patients to predict whether they will be suitable for opening of the blood - tumour barrier with bradykinin or its analogue.

[Relationship between gastric cancer and gene amplification of p14 and mdm2].

BACKGROUND & OBJECTIVE: Some genes are related to the occurrence of tumor. p53 is one of these kinds of gene. Mdm2 and p14 can modulate the function of p53. However, the reports about the function of mdm2 and p14 in gastric tumor are rare. The aim of this study was to observe the change of oncogene mdm2 and suppressor cancer gene p14 in gastric cancer cell and to investigate the relationship of mdm2, p14 with gastric cancer. METHODS: A total of 55 gastric mucosal biopsy specimens were enrolled, including 10 of normal gastric mucosa and 45 gastric tumor, which were proved pathologically as adenoma, including 15 poorly, moderately, and well differentiated specimens, respectively. The mRNA expression of mdm2 and p14 in gastric cancer were identified by reverse transcription polymerase chain reaction (RT-PCR), and the relationship of mdm2, p14 with gastric cancer was analyzed. RESULTS: (1) There was significant difference of the expression positive ratio of mdm2 mRNA between gastric tumor and normal gastric tissues (73.3% vs. 40%) (P< 0.05) [93.3% for the well differentiated specimens, 80.0% for the moderately differentiated specimens, and 46.6% for the poorly differentiated specimens]. There was significant difference between any two groups of the three specimens (P< 0.05). (2) There was no significant difference of the expression positive ratio of p14 mRNA between gastric tumor and normal gastric tissues (60.0% vs. 50.0%) (P >0.05) [60.0% for the well differentiated specimens, 66.6% for the moderately differentiated specimens, and 53.5% for the poorly differentiated specimens]. There was no significant difference between any two groups of the three specimens (P >0.05). CONCLUSION: The mRNA expression of mdm2 is closely correlated with the progression of gastric cancer. The relationship between p14 and gastric tumor has not been tested in this study and further study will be needed.