title: Malignant transformation of a cloned, nontumorigenic mouse epidermal keratinocyte cell line, MSK-C3H-NU, by 7,12-dimethylbenz(a)anthracene.
abstract: MSK-C3H-NU, a cloned mouse epidermal keratinocyte cell line, was established from the epidermis of C3H/HeN mammary tumor virus-positive nude mice. Although it has lost its diploid chromosome number, the cell line is nontumorigenic, has been stable during serial subcultivations for over 2 years, and has retained some differentiated biological characteristics of normal keratinocytes. MSK-C3H-NU cells were cultured in growth medium containing 7,12-dimethylbenz(a)anthracene. After 2 months, colonies exhibited marked changes in cell morphology, cell arrangement, and keratinization pattern that appeared. The transformation frequency per 10(5) survivors in 7,12-dimethylbenz(a)anthracene-treated (10, 100, and 500 ng/ml) subgroups was 0, 119, and 1370 for Experiment I and 3.9, 238, and 2500 for Experiment II, respectively. Most of these transformed cells became malignant and formed tumors in nude mice. Histologically, the tumors were well-differentiated, keratinizing, squamous cell carcinomas showing papillary growths. In 7,12-dimethylbenz(a)anthracene-treated subgroups, cells from colonies that retained the original morphological characteristics did not form tumors in animals, and in control groups, no cell population showed tumorigenicity. In the MSK-C3H-NU cell system, the morphological alterations seem to be strongly associated with malignant conversion.
authors.forename: K
authors.initials: K
authors.lastname: Indo
authors.forename: H
authors.initials: H
authors.lastname: Miyaji
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002875:Chromosomes / Q000032:analysis; D002999:Clone Cells; D007633:Keratins; D051379:Mice; D008809:Mice, Inbred C3H / Q000235:genetics; D008819:Mice, Nude; D012878:Skin Neoplasms / Q000473:pathology*
chemical_list: D015127:9,10-Dimethyl-1,2-benzanthracene; D007633:Keratins