Abstract |
The effect of a methyl substituent at the non-benzo ring bay-region position of benzo[e]pyrene (B[e]P), cholanthrene (CA) and dibenz[a,j] anthracene (DB[a,j]A) on skin tumor-initiating activity was examined. A methyl substituent at the 1-carbon of B[e]P enhanced tumor-initiating activity of the parent compound (0.18 vs. 2.4 papillomas/mouse for B[a]P vs. 1-methyl-B[e]P, respectively, with an 800 nmol initiating dose). A methyl substituent at the 7- and 14-carbons of DB[a,j]A increased the activity of this weak initiator more than 13 times. The introduction of a methyl substituent at the non-benzo ring bay-region position of CA (i.e. carbon atom 6) dramatically increased tumor-initiating activity in SENCAR mice. 6-Methyl-CA was found to be a more potent skin tumor-initiator than 3-methyl-CA, and nearly as potent as 7,12-dimethylbenz[a] anthracene, one of the most potent initiators yet tested in the 2-stage initiation-promotion mouse skin model. When taken together with previous results from our laboratories, the data further support the generality of the enhancing effect of a non-benzo ring bay-region methyl substituent on polycyclic hydrocarbon tumor-initiation.
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Authors | T W Sawyer, K Chang, R G Harvey, J DiGiovanni |
Journal | Cancer letters
(Cancer Lett)
Vol. 36
Issue 3
Pg. 317-24
(Sep 1987)
ISSN: 0304-3835 [Print] Ireland |
PMID | 3115560
(Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Benz(a)Anthracenes
- Benzopyrenes
- Carcinogens
- 6-methylcholanthrene
- Benzo(a)pyrene
- cholanthrene
- Methylcholanthrene
- 9,10-Dimethyl-1,2-benzanthracene
- 7,14-dimethyldibenz(a,j)anthracene
- 1-methylbenzo(e)pyrene
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Topics |
- 9,10-Dimethyl-1,2-benzanthracene
(toxicity)
- Animals
- Benz(a)Anthracenes
(toxicity)
- Benzo(a)pyrene
(toxicity)
- Benzopyrenes
(toxicity)
- Carcinogens
- Female
- Methylcholanthrene
(analogs & derivatives, toxicity)
- Mice
- Papilloma
(chemically induced)
- Skin Neoplasms
(chemically induced)
- Structure-Activity Relationship
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