RESUMO
Objective: To investigate the effects of early exposure of new born rats to octylphenol (OP) on breast cancer incidence and breast cancer susceptibility gene 1 (BRCA1) expression. Methods: Female Sprague-Dawley rats were randomly divided into control (Con) group, model (Mod) group, OP 20, OP 40, OP 80 groups. OP was subcutaneously injected into rats from d 21 to d 27. The rats were given dimethylbenz[a]anthracene (DMBA) intragastrically on d 42 and were sacrificed on 180 d. The incidence of breast cancer, the changes in serum levels of estradiol and progesterone, the alteration of estrogen receptor (ER) expression and BRCA1 mRNA and protein expression in breast cancer tissues were observed. Results: No breast cancer occurred in Con group. The incidence rate of breast cancer in the Mod group, OP 20 group, OP 40 group, and OP 80 group were 70% (14/20), 60% (12/20), 25% (5/20), and 50% (10/20), respectively. The fluorescence intensities of BRCA1 expression were 31.54 ± 6.15, 36.27 ± 7.57, 61.69 ± 9.96 and 47.38 ± 10.45, respectively; the logarithm value of BRCA1 mRNA expressions were 3.46 ± 6.52, 4.12 ± 0.86, 5.53 ± 0.75, and 4.35 ± 0.58, respectively. The ER expression in breast cancer tissues decreased after the rats were exposed to OP. Conclusion: OP decreased the occurrence of DMBA-induced breast cancers, which may be related with up-regulation of BRCA1 expression and down-regulation of ER expression in breast cancers.
RESUMO
<p><b>OBJECTIVE</b>To study the difference in the expressions of C-erbB-2 gene between the coal miners with pneumoconiosis complicated by pulmonary cancer and the controls with single pulmonary cancer, and its relation to clinical pathology.</p><p><b>METHOD</b>Measuring the expressions of C-erbB-2 in 32 cases of pneumoconiosis complicated by pulmonary cancer and those in 30 cases of pulmonary cancer by means of immunohistochemistry.</p><p><b>RESULTS</b>The positive expression rate in 32 cases of pneumoconiosis complicated by pulmonary cancer was 53.13% whereas that in 30 cases of single pulmonary cancer was 26.67% (P < 0.05); the positive expressions of C-erbB-2 in patients with lymph node metastasis (70.59% in pneumoconiosis group, 50.00% in controls) were significantly different from those without lymph node metastasis (33.33% in pneumoconiosis group, 11.11% in controls) (P < 0.05). The prognosis on patients with positive expressions of C-erbB-2 was poor, and was not related to pathologic category.</p><p><b>CONCLUSION</b>C-erbB-2 gene may be an important regulating gene in the coal miners with pneumoconiosis complicated by pulmonary cancer, and as a reference index to determine lymph node metastasis and prognosis.</p>