ABSTRACT
AIM: To investigate the role of Δ133p53 isoform in nuclear factor-κB (NF-κB) inhibitor pyrrolidine dithiocarbamate (PDTC)-mediated growth inhibition of MKN45 gastric cancer cells. METHODS: The growth rate of MKN45 cells after treatment with different concentrations of only PDTC or PTDC in combination with cisplatin was detected by the CCK-8 assay. mRNA expression levels of Δ133p53, p53ß, and the NF-κB p65 subunit and p65 protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence, respectively. Growth of MKN45 cells was significantly inhibited by PDTC alone in a dose-dependent manner (P < 0.01). Moreover, the inhibitory effect of cisplatin was remarkably enhanced in a dose-dependent manner by co-treatment with PDTC (P < 0.01). RESULTS: RT-PCR analysis revealed that mRNA expression of p65 was curbed significantly in a dose-dependent manner by treatment with only PDTC (P < 0.01), and this suppressive effect was further enhanced when co-treated with cisplatin (P < 0.01). With respect to the other p53 isoforms, mRNA level of Δ133p53 was significantly reduced in a dose-dependent manner by treatment with only PDTC or PTDC in combination with cisplatin (P < 0.01), whereas p53ß mRNA expression was not altered by PDTC treatment (P > 0.05). A similar tendency of change in p65 protein expression, as observed for the corresponding mRNA, was detected by immunofluorescence analysis (P < 0.01). Pearson correlation analysis demonstrated that Δ133p53 and p65 mRNA expression levels were positively related, while no significant relationship was observed between those of p65 and p53ß (r = 0.076, P > 0.01). CONCLUSION: Δ133p53 isoform (not p53ß) is required in PDTC-induced inhibition of MKN45 gastric cancer cells, indicating that disturbance in the cross-talk between p53 and NF-κB pathways is a promising target in pharmaceutical research for the development of treatment strategies for gastric cancer.
Subject(s)
NF-kappa B/antagonists & inhibitors , Oncogene Protein p65(gag-jun)/metabolism , Pyrrolidines/pharmacology , Stomach Neoplasms/metabolism , Thiocarbamates/pharmacology , Tumor Suppressor Protein p53/metabolism , Cell Line, Tumor , Humans , NF-kappa B/metabolism , Protein Isoforms/metabolism , Pyrrolidines/therapeutic use , Stomach Neoplasms/drug therapy , Thiocarbamates/therapeutic useABSTRACT
A method was established for the determination of soil available B by inductively coupled plasma mass spectrometry (ICP-MS). Compared to the traditional method for B analysis, the recommended method does not need filtration, so it escapes the contamination. The method not only proved simple and rapid, but also showed satisfying precision and accuracy. The detection limit of this method is 0.009 ng x g(-1). The relative standard deviation is 2.66%, and the recovery is 93.0%-102.0%.
ABSTRACT
A method was studied for the analysis of 11 kinds of trace elements(Cr, Mn, Ni, Co, Cu, Zn, As, Se, Mo, Cd and Pb) in root-like and rootstalk-like dried medicinal herbs by microwave digestion-ICP-MS. A digestion method was developed for trace elements analysis for two types of herbs. The Microwave digestion condition was optimized in terms of digestion system, proportion of acids, and digestion procedure, which affords reference to the preparation of the same kinds of dried medicinal herbs. The detection limits of the method for all sample elements were in the range of 0. 001-0. 260 microg x g(-1), the RSDs were between 0. 4%-3. 1% and the recoveries were between 90% and 110%.
