Abstract
Previous studies showed that 5,6-dimethylchrysene (5,6-diMeC) and 5,7-diMec were significantly less tumorigenic than 5-methylchrysene (5-MeC). These results were unexpected based on the known mechanism of metabolic activation of 5-MeC and indicated the presence of critical steric requirements for tumorigenicity at the 6 and 7 positions of 5-MeC. In this study, the structure activity relationships were further extended by comparing the tumor-initiating activities on mouse skin of 5-MeC, 6,7-cyclopentano-5-MeC, 5,6-diMeC, 6,7-diMeC, 5,7-diMeC, chrysene and 6,7-cyclopentanochrysene. 5-MeC was the most tumorigenic compound, with activity significantly higher than all other compounds tested. Among the other compounds, only 5,6-diMeC was significantly tumorigenic. The results demonstrate that substitution of methyl or methylene groups at the 6 or 7 positions of 5-MeC leads to a significant reduction of tumor initiating activity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 17-20 |
| Number of pages | 4 |
| Journal | Cancer Letters |
| Volume | 51 |
| Issue number | 1 |
| DOIs | |
| State | Published - May 15 1990 |
Bibliographical note
Funding Information:We thankV eronicaS aa and BijayaM israf or their technicala ssistanceT. his study was supported by Grant No. CA-44377 from the National Cancer Institutea nd Grant No. ES-04266 from the NationalI nstituteo f Environ-mentalH ealthS ciences.T his is paper no. 133 in “A Study of ChemicalC arcinogenesis”.
Keywords
- 5-methylchrysene
- cyclopentanochrysenes
- dimethylchrysenes
- tumor initiation