[The expression of bcl-2 and bax genes during microcystin induced liver tumorigenesis].
OBJECTIVE
To study the molecular mechanism of microcystin (MC) induced liver tumorigenesis in rats.


METHODS
The two-stage-medium-term tumorigenesis theory was applied to establish the animal model, and the effect of MC in liver tumor formation was evaluated by the Albert gamma-GT methods, and then, the immunohistochemical technique and image analysis were used to study the expression of the bcl-2 and bax genes during tumorigenesis.


RESULTS
(1) MC enhanced the formation of gamma-GT foci in liver (100%), which was significantly higher than the diethylnitrosamine (DEN) control group (22.22%) (P < 0.05). (2) MC decreased the expression of bax gene. The intensity and area of bax gene expression in the pure MC toxin group were 0.028 3 AODV and 0.007 3 ( micro m(2)/ micro m(2)) and in the DEN control group were 0.065 5 AODV and 0.024 4 ( micro m(2)/ micro m(2)), respectively. The intensity and areas of bax gene expression in the pure MC toxin group were significantly lower than those in the DEN control group (P < 0.05). (3) MC increased the expression of bcl-2 gene. The intensity and area of bcl-2 gene expression in the pure MC toxin group wee 0.097 7 AODV and 0.031 5 ( micro m(2)/ micro m(2)), respectively, and in the DEN control group were 0.046 0 AODV and 0.020 5 ( micro m(2)/ micro m(2)) respectively (P < 0.05).


CONCLUSIONS
(1) MC can strongly promote liver tumorigenesis. (2) The changes of bcl-2 and bax gene expression possibly play an important role in the MC induced liver tumor formation.
Hu
Zhijian
Z
School of Public Health, Fujian Medical University, Fuzhou, 350004, China.
Chen
Hua
H
Li
Yiwei
Y
Gao
Lingyun
L
Sun
Changsheng
C
D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D007150:Immunohistochemistry; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D052998:Microcystins; D010456:Peptides, Cyclic / Q000633:toxicity*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D051028:bcl-2-Associated X Protein
C494827:Bax protein, mouse; C494828:Bax protein, rat; D002273:Carcinogens; D052998:Microcystins; D010456:Peptides, Cyclic; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C078588:microcystin