title: N-nitroso-N-ethylurea-induced hamster melanoma: a new method for efficient induction and schwannian differentiation of melanoma.
abstract: Melanocytic tumors as well as multiple neurofibromas were induced in 35 of 88 Syrian golden hamsters by a single s.c. administration of 100 mg/kg of N-nitroso-N-ethylurea applied 48 h after birth. The lesions were all observed proliferating in the dermis and demonstrated melanosomes and premelanosomes. High cellularity, nuclear atypia and transplantability of the tumors in outbred hamsters suggested a malignant nature. Some of the melanomas were morphologically heterogenous and contained Schwann-like cells as minor components. In addition, transplantation of the melanomas resulted in increased schwannian differentiation even for primary tumors which did not contain any Schwann-like cell foci. One of the transplanted melanomas mimicked malignant peripheral nervous tumor. Schwannian differentiation was also proved by the fact that glial fibrillary acidic protein was positive in 22.2% of the cases. The present results suggest that the induced hamster melanomas originate from neural crest-derived cells which are able to differentiate into both melanocytes and Schwann cells.
authors.affiliation: Department of Pathology, Faculty of Medicine, Tokyo Medical and Dental University.
authors.forename: T
authors.initials: T
authors.lastname: Nemoto
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Ohashi
authors.forename: T
authors.initials: T
authors.lastname: Kasuga
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D006224:Cricetinae; D005038:Ethylnitrosourea / Q000633:toxicity*; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D007150:Immunohistochemistry; D008297:Male; D008546:Melanoma, Experimental / Q000139:chemically induced / Q000473:pathology* / Q000648:ultrastructure; D008647:Mesocricetus; D008854:Microscopy, Electron; D009368:Neoplasm Transplantation; D012583:Schwann Cells / Q000473:pathology*; D012737:Sex Factors
chemical_list: D005904:Glial Fibrillary Acidic Protein; D005038:Ethylnitrosourea