caa a22 4500 477081665 CHVBK 20180405111451.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF02722947 doi (NATIONALLICENCE)springer-10.1007/BF02722947 Tumorigenesis of rat mammary epithelial cells by N-nitroso-N-methylurea in an in vitro system: Characterization of the microtumors [Elektronische Daten] [Jeffrey Laduca, Dilip Sinha] Summary: Chemical carcinogenesis is a lengthy process that involves the rather loosely defined stages of initiation, promotion, and progression. Several model systems of mammary carcinogenesis have been designed to elucidate the mechanisms of chemical carcinogenesis. Most of these systems have included animal models. While organ specific chemical carcinogenesis can be initiated in these systems, the subsequent stages of promotion and progression are difficult to study in detail. Investigations onin vitro carcinogenesis have shown transformation of mammalian cells in culture; the transformational event, however, is difficult to discern within the monolayer culture. We have recently reported the development of anin vitro carcinogenesis system that allows both the initiation as well as the progression of mammary cells in a collagen gel matrix culture system. The cells transformed by a chemical carcinogen develop into discernible microtumors with the three dimensions of a collagen gel culture. Isolation of these microtumors from the collagen gel an subsequent culture in monolayer has produced cells capable of colony formation in soft agar. The present study further characterizes these microtumors originatedin vitro by analysis of cell growth kinetics versus parallel control cells. In addition, flow cytometric and cytogenetic studies have been performed to investigate the chromosomal stability of these cells. It was also observed that the microtumors, producedin vitro from mammary epithelial cells of an inbred strain of rats, show the ability to form tumors upon transplantation into the fat pad of syngeneic hosts. Society for In Vitro Biology, 1996 mammary nationallicence in vitro nationallicence carcinogenesis nationallicence collagen nationallicence Laduca Jeffrey Department of Breast Surgery and Breast Cancer Research Unit, Roswell Park Cancer Institute, Elm and Carlton Streets, 14263, New York aut Sinha Dilip Department of Breast Surgery and Breast Cancer Research Unit, Roswell Park Cancer Institute, Elm and Carlton Streets, 14263, New York aut In Vitro Cellular & Developmental Biology - Animal Springer-Verlag 32/4(1996-04-01), 204-210 1071-2690 32:4<204 1996 32 11626 https://doi.org/10.1007/BF02722947 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02722947 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Laduca Jeffrey Department of Breast Surgery and Breast Cancer Research Unit, Roswell Park Cancer Institute, Elm and Carlton Streets, 14263, New York aut NATIONALLICENCE 700 1- Sinha Dilip Department of Breast Surgery and Breast Cancer Research Unit, Roswell Park Cancer Institute, Elm and Carlton Streets, 14263, New York aut NATIONALLICENCE 773 0- In Vitro Cellular & Developmental Biology - Animal Springer-Verlag 32/4(1996-04-01), 204-210 1071-2690 32:4<204 1996 32 11626 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer