A single topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA) was found to induce mRNA of a metallothionein (MT) gene or genes in the skin of Sencar mice, and papillomas produced by repeated applications of TPA were shown to have elevated levels of MT mRNA. Induction of MT mRNA was maxi
The development of contact hypersensitivity in mouse skin is suppressed by tumor promoters
β Scribed by Brian Czerniecki; Gisela Witz; Christopher Reilly; Shayne C. Gad
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 847 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0260-437X
No coin nor oath required. For personal study only.
β¦ Synopsis
The ability of tumor promoters to suppress the development of contact hypersensitivity (CHS) was assessed by the mouse ear swelling assay. Application of the complete or second stage tumor promoters phorbol-12myristate-13-acetate (PMA, 2 pg), croton oil (1%). benzoyl peroxide (20 mg), mezerein ( 2 pg), or phorbol-12-retinoate-13-acetate (PRA, 2 kg) to the abdominal surface of CF-I female mice for 1 week (three treatments) prior to the sensitization of the same location with 0 . 5 8 I-chloro-2,4-dinitrobenzene (DNCB) resulted in a SO% suppression ( p cO.O.5) of the CHS response to DNCB. The first stage tumor promoters 4-0-Me-PMA (80 kg), calcium ionophore A23187 (80 kg), hydrogen peroxide ( 1.5% and the non-promoting analogs phorbol-12,13-diacetate (PDA, 20 Fg), phorbol (80 pg) or acetone did not suppress the response. The suppression of the development of CHS caused by PMA was dependent on the promoter being applied at the site of induction and was inhibited by application of the phospholipase A2 inhibitor dibromoacetophenone ( 100 pg), the Lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA, 100 pg), or the antiinflammatory steroid fluwinolone acetonide (2 pg). Application of PMA or mezerein 24 h prior to challenge with DNCB. to the ears of mice previously sensitized with DNCB resulted in a significant enhancement of the ear swelling response by 60% and 110%. respectively, compared with controls. The results demonstrate that tumor promoters suppress the development of CHS, and suggest the possibility that second stage promotion may involve suppression of the development of a tumor specific immune response.
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