title: Altered pattern of growth and differentiation in human keratinocytes infected by simian virus 40.
abstract: Human epidermal keratinocytes were infected by simian virus 40 in vitro. The structure of the developing keratinocyte colony reflects the spatial separation of cell division and keratinization in intact skin; thymidine-incorporating cells were primarily localized at the colony periphery whereas nondividing, histologically differentiated cells accumulated in the interior. Viral infection produced a dramatic increase in the size of the proliferative population as, simultaneously, differentiation was reduced in the colony interior. These changes were manifest when simian virus 40 T-antigen synthesis was detectable in only a small percentage of the cells; differentiation became increasingly density dependent as the percentage of T-antigen-positive cells rose over serial passage. The disruption of the normal pattern of growth/differentiation localization coincided with a loss of dependence on serum for growth, but preceded the appearance of other virus-induced properties associated with transformation; i.e., the ability to form colonies in soft agar and independence of growth from fibroblasts.
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis; D000956:Antigens, Viral / Q000032:analysis; D002454:Cell Differentiation; D002455:Cell Division; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004817:Epidermis / Q000254:growth & development / Q000382:microbiology; D006801:Humans; D007633:Keratins / Q000378:metabolism*; D013539:Simian virus 40 / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D000956:Antigens, Viral; D007633:Keratins