Isolation and characterization of variant benzo[a]pyrene-resistant T47D human breast-cancer cells

✍ Scribed by Michael Moore; Mary Ruh; Michael Steinberg; Stephen Safe

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: French
• Weight: 946 KB
• Volume: 66
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19960328)66:1<117::aid-ijc20>3.0.co;2-9

✦ Synopsis

T47D human breast cancer cells were grown in I pM benzo[a]pyrene (BaP) for 3.5 months, and 2 BaP-resistant (BaPR) variant cell lines (C5 and CIO) were isolated. Decreased aryl hydrocarbon (Ah)-responsiveness in the C5 and C I0 BaPR cells was characterized by lower (80 to 9ovo) induction of CYP I A l -dependent activity by 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD), lower levels of the nuclear Ah receptor complex and significantly decreased Ah receptor mRNA levels. Nuclear estrogen receptor (ER) binding and ER mRNA levels were similar in wild-type and mutant cell lines, whereas epidermal growth factor receptor mRNA levels were significantly decreased in the variant BaPR T47D cells. I7P-Estradiol induced proliferation of both wild-type and BaPR T47D cells, and TCDD inhibited this response but did not down-regulate nuclear ER levels. The unique characteristics of the BaPR T47D variant cells will be used to further elucidate the mechanism of interaction between the ER and Ah receptor signalling pathways.