Tumors of the skin in the HRA/Skh mouse after treatment with 8-methoxypsoralen and UVA radiation.
8-Methoxypsoralen (8-MOP) with and without UVA radiation was administered to HRA/Skh mice (36 animals per treatment group) three times a week in the feed for a total dose of 9-80 mg/kg/week for 52 weeks. Most of the animals at the top dose of 8-MOP with UVA radiation had developed skin toxicity and/or skin tumors by 52 weeks. The skin lesions seen after treatment with 8-MOP and UVA radiation were characterized as squamous cell hyperplasia, squamous cell papilloma, and squamous cell carcinoma and are similar to what has been reported in humans after exposure to 8-MOP and UVA. Squamous cell hyperplasia and acute inflammation of the cornea were also seen in some of the treated female mice. Oral administration of 8-MOP and UVA did not result in a carcinogenic response to other organ systems. There were no increases in skin neoplasms after 8-MOP or UVA radiation alone. 8-MOP given in combination with UVA was carcinogenic to the skin of mice at dose levels similar to those used to treat psoriasis in humans.
Dunnick
J K
JK
National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Forbes
P D
PD
Eustis
S L
SL
Hardisty
J F
JF
Goodman
D G
DG
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000209:etiology*; D005128:Eye Diseases / Q000209:etiology / Q000473:pathology; D005260:Female; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D008815:Mice, Inbred Strains; D011701:PUVA Therapy / Q000009:adverse effects*; D012737:Sex Factors; D012867:Skin / Q000473:pathology; D012871:Skin Diseases / Q000209:etiology / Q000473:pathology; D012878:Skin Neoplasms / Q000209:etiology*