Inhibition on Hepatitis B virus in vitro of recombinant MAP30 from bitter melon.

The gene encoding MAP30 protein was cloned from bitter melon and recombinant MAP30 was expressed and purified. The human hepatoma G2.2.15 cells were exposed to different concentrations of MAP30. MTT assay was used to evaluate the cytotoxicity of the drugs and real-time PCR and Southern hybridization were applied to quantify extracellular HBV DNA and replicative intermediates intracellular and cccDNA in nucleus. HBsAg and HBeAg were assessed by enzyme-linked immunosorbent assay (ELISA). The results showed that exposure of HepG2.2.15 cells to MAP30 resulted in inhibition of HBV DNA replication and HBsAg secretion. After exposed to three different concentrations of MAP30 for 2, 4, 6, and 8 days respectively, the inhibition rates of extracellular HBV DNA, HBsAg, and HBeAg of each concentration decreased significantly (P < 0.05). After 9 days of treatment, the inhibition rates of extracellular HBV DNA of the different concentrations differed greatly (P < 0.001). The MAP30 could inhibit the production of HBV (P < 0.01) dose-dependently. The expression of HBsAg was significantly decreased by MAP30 dose-dependently (P < 0.001) and time-dependently (P < 0.001). Lower dose of MAP30 (8.0 microg/ml) could inhibit the expression of HBsAg and HBeAg.

Effects of recombinant MAP30 on cell proliferation and apoptosis of human colorectal carcinoma LoVo cells.

MAP30, an attractive protein isolated from bitter melon, has been previously found to have the anti-tumor and anti-HIV activities. In this study, MAP30 was cloned and expressed and the effects of the recombinant protein on cell proliferation and apoptosis of human colorectal carcinoma LoVo cells were investigated. The results showed that the proliferation of LoVo cells were significantly suppressed by MAP30 in time- and dose-dependent manners at the concentration ranging from 0.67 to 4.67 muM. The apoptotic nuclei of LoVo cells induced by MAP30 were obviously observed, and the genomic degradation was detected by single-cell gel electrophoresis (comet assay). Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy. The proportion of the periodic tumor cells was altered by MAP30. Sub-G1 curves were displayed by a flow cytometry analysis. Results of northern and western blots showed that the transcription and expression of Bax, a member of pro-apoptotic proteins, were gradually up-regulated as treated time increased. On the contrary, the transcription and expression of Bcl-2, an anti-apoptotic member, were down-regulated. These data provided powerful evidences for the first time that recombinant MAP30 can induce the apoptosis of the human colorectal carcinoma LoVo cells.

[Effect of coking oven emissions on level of serum oxidation-reduction and peripheral white blood cellular ras P21 and P53 in coke oven workers].

OBJECTIVE: To explore the adverse effects of coking oven emissions (COE) on the serum oxidation-reduction and relevant genes in the exposed workers. METHODS: Fifty-six coke oven workers and forty controls were investigated. Serum Malondialdehyde (MDA) levels and the activities of total superoxide dismutases (T-SOD) were measured by spectrophotometrical method. Immunohistochemical method was used to assess the P21 and P53 levels in peripheral white blood cells. RESULTS: Compared with controls, the individuals exposed to COE had significantly increased levels of serum MDA [(5.30 +/- 2.29) nmol/mL, P < 0.01] and markedly decreased levels of T-SOD [(100.04 +/- 10.75) NU/mL]. Additionally, the median levels of P53 and P21 were markedly increased in the exposed individuals compared with the controls (21.4% and 23.2%, respectively, all P < 0.05). CONCLUSION: The findings indicate that occupational exposure to COE causes the rise of serum oxidation-reduction MDA and the fall of T-SOD, and increasing expression levels of P21 and P53 proteins before the occurrence of apparent clinical symptoms.

[Study of IL-8 overexpression in A549 cells induced by crocidolite fibers].

OBJECTIVE: This study was to investigate the effect of crocidolite fibers on IL-8 protein and mRNA levels in A549 cells cultured supernatant and the role of tyrosine kinase inhibitor PD98059 on IL-8 expression. METHODS: Real Time PCR and ELISA were employed to detect A549 cellular IL-8 mRNA and supernatant IL-8 protein, respectively. RESULTS: After incubating cells with 100 microg/ml of crocidolite, IL-8 protein releasing in supernatant was significantly increased and IL-8 mRNA was also higher than that of control, the differences were statistically significant (P < 0.05), however both IL-8 protein and mRNA was abrogated by pretreating cells with tyrosine kinase inhibitor PD98059. CONCLUSION: IL-8 was shown as overexpression and could be decreased by PD98059. This indicated that MAPK signal pathway is involved in the process IL-8 expression.