To investigate the relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene, RASSF1A protein expression was measured by Western blotting in 10 specimens of normal bladder ti...To investigate the relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene, RASSF1A protein expression was measured by Western blotting in 10 specimens of normal bladder tissues and 23 specimens of bladder transitional cell carcinoma (BTCC). The promoter methylation in BTCC and normal bladder tissues was detected by methylation-specific PCR (MSP). The results showed that the expression level of RASSF1A protein was significantly lower in BTCC tissues than that in normal bladder tissues. However, it was not correlated with its clinical stages and pathological grades. The frequency of promoter methylation of RASSF1A gene was higher in BTCC tissues than that in normal bladder tissues. In 14 patients with the aberrant promoter methylation, 13 showed loss or low expression of RASSF 1A protein. It is concluded that RASSF1A gene promoter methylation may contribute to the low level or loss of RASSF1A protein expression, the inactivation of RASSF1A gene and the genesis of BTCC. But, it may bear no correlation with its clinical stages and pathological grades.展开更多
4,4’-Methylenebis(2-chloroaniline) (MBOCA) is a probable human carcinogen. Few studies have been performed regarding the genotoxicity of MBCOA, and the MBOCA metabolic pathway is not fully understood. We treated four...4,4’-Methylenebis(2-chloroaniline) (MBOCA) is a probable human carcinogen. Few studies have been performed regarding the genotoxicity of MBCOA, and the MBOCA metabolic pathway is not fully understood. We treated four-week-old ICR male mice weighing 25 - 30 g with MBOCA and observed the effects of MBOCA on the internal organs. It can be concluded that MBOCA is a carcinogen and also affects gene regulation. Oral or topical administration of 50 mg/kg, 100 mg/kg or 200 mg/kg MBOCA resulted in 56% - 81% of mice showing unusual inflammation, degeneration, and dysplasia in kidney, liver, stomach, intestine and urinary bladder based on histology. Furthermore, we investigated the association between oxidative DNA damage and MBOCA exposure by measuring plasma level of 8-hydroxydeoxyguanosine (8-OHdG). The results showed that the MBOCA-treated mice had significantly higher 8-OHdG levels than the control mice. This study confirms that MBOCA is potentially carcinogenic and highly toxic to both animals and humans.展开更多
基金a grant from the National Natural Sciences Foundation of China (No. 30571858)
文摘To investigate the relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene, RASSF1A protein expression was measured by Western blotting in 10 specimens of normal bladder tissues and 23 specimens of bladder transitional cell carcinoma (BTCC). The promoter methylation in BTCC and normal bladder tissues was detected by methylation-specific PCR (MSP). The results showed that the expression level of RASSF1A protein was significantly lower in BTCC tissues than that in normal bladder tissues. However, it was not correlated with its clinical stages and pathological grades. The frequency of promoter methylation of RASSF1A gene was higher in BTCC tissues than that in normal bladder tissues. In 14 patients with the aberrant promoter methylation, 13 showed loss or low expression of RASSF 1A protein. It is concluded that RASSF1A gene promoter methylation may contribute to the low level or loss of RASSF1A protein expression, the inactivation of RASSF1A gene and the genesis of BTCC. But, it may bear no correlation with its clinical stages and pathological grades.
文摘4,4’-Methylenebis(2-chloroaniline) (MBOCA) is a probable human carcinogen. Few studies have been performed regarding the genotoxicity of MBCOA, and the MBOCA metabolic pathway is not fully understood. We treated four-week-old ICR male mice weighing 25 - 30 g with MBOCA and observed the effects of MBOCA on the internal organs. It can be concluded that MBOCA is a carcinogen and also affects gene regulation. Oral or topical administration of 50 mg/kg, 100 mg/kg or 200 mg/kg MBOCA resulted in 56% - 81% of mice showing unusual inflammation, degeneration, and dysplasia in kidney, liver, stomach, intestine and urinary bladder based on histology. Furthermore, we investigated the association between oxidative DNA damage and MBOCA exposure by measuring plasma level of 8-hydroxydeoxyguanosine (8-OHdG). The results showed that the MBOCA-treated mice had significantly higher 8-OHdG levels than the control mice. This study confirms that MBOCA is potentially carcinogenic and highly toxic to both animals and humans.