Objective To investigate the antitumor activity of the procaspase-3 activator SM-1 in BGC-823 cells in vivo and in vitro and the mechanisms.Methods The inhibitory effects of SM-1 on proliferation of BGC-823 cells were evaluated using MTT method, the cell apoptosis rate was detected by flow cytometry, and the expression of caspase-3 protein and procaspase-3 mRNA was detected by Western blotting and RT-PCR, respectively.SM-1 Antitumor activity was evaluated using the xenograft of BGC-823 cells in nude mice.Results SM-1 effectively inhibited the proliferation in vitro and in-duced apoptosis of BGC-823 cells in a dose-dependent manner.After treatment with SM-1 for 48 h, the protein expression levels of caspase-3 and mRNA expression levels of procaspase-3 were increased.SM-1 significantly inhibited growth of BGC-823 xenograft tumor at the 300 mg/kg dose and the inhibition rate was 56.3%(P<0.05).Conclusion SM-1 can significantly inhibit the tumor growth of BGC-823 cells in vivo and in vitro.The mechanism is possibly related to the activation of procaspase-3 and induced apoptosis of tumor cells.

BACKGROUND:Previous studies have shown that minichromosome maintenance 3 is related with fluorosis, but the expression of minichromosome maintenance 3 in fluorosis patients is not clear yet.
OBJECTIVE:To analyze the mRNA expression level of minichromosome maintenance 3 in peripheral blood from patients exposed to fluoride and normal controls.
METHODS:Eleven patients with mild fluorosis by drinking water (exposure group) and 11 cases of control (non-exposure group) were selected for research. SYBRGreen1 real-time quantitative PCR was used to determine the mRNA expression of minichromosome maintenance 3 in peripheral blood mononuclear cel s, and the liver and renal function indicators were detected.
RESULTS AND CONCLUSION:mRNA expressions of minichromosome maintenance 3 in the exposure group and non-exposure group were (0.573 60±0.102 59) and (0.550 0±0.171 81), respectively, and there was no significant difference between two groups (P>0.05). There were no significant differences in the liver and renal function indicators between two groups. The results indicate that mild fluorosis has no significant effect on mRNA expression of minichromosome maintenance 3 in the peripheral blood mononuclear cel s. More indicators are needed to compressively analyze the effect of fluoride on the liver and renal functions.

The corona-like spikes or peplomers on the surface of the virion under electronic microscope are the most striking features of coronaviruses. The S (spike) protein is the largest structural protein, with 1,255 amino acids, in the viral genome. Its structure can be divided into three regions: a long N-terminal region in the exterior, a characteristic transmembrane (TM) region, and a short C-terminus in the interior of a virion. We detected fifteen substitutions of nucleotides by comparisons with the seventeen published SARS-CoV genome sequences, eight (53.3%) of which are non-synonymous mutations leading to amino acid alternations with predicted physiochemical changes. The possible antigenic determinants of the S protein are predicted, and the result is confirmed by ELISA (enzyme-linked immunosorbent assay) with synthesized peptides. Another profound finding is that three disulfide bonds are defined at the C-terminus with the N-terminus of the E (envelope) protein, based on the typical sequence and positions, thus establishing the structural connection with these two important structural proteins, if confirmed. Phylogenetic analysis reveals several conserved regions that might be potent drug targets.
Amino Acid Sequence ; Antigens, Viral ; immunology ; Base Composition ; Computational Biology ; Enzyme-Linked Immunosorbent Assay ; Membrane Glycoproteins ; genetics ; Molecular Sequence Data ; Mutation ; genetics ; Phylogeny ; Protein Structure, Tertiary ; SARS Virus ; genetics ; immunology ; Sequence Analysis, DNA ; Sequence Homology ; Spike Glycoprotein, Coronavirus ; Viral Envelope Proteins ; genetics ; metabolism