PROPERTIES OF INCOMPLETELY IMMORTALIZED CELL-LINES GENERATED FROM LINE ESTABLISHED FROM TEMPERATURE-SENSITIVE SV40 T-ANTIGEN GENE TRANSGENIC MICE

Kidney tubule cell Line (TKC2) established from temperature-sensitive (ts) SV40 T-antigen gene transgenic mice exhibited cell death by apopt osis at nonpermissive temperature (39 degrees C). To learn how immorta lization occurs, we generated T-antigen-independent immortalized cells (resistant clones) by culturing TKC2 cells at 39 degrees C. These ind ependently isolated resistant clones exhibited ts properties in T-anti gen and contained only wild-type p53. They grew similarly at 39 degree s and at 33 degrees C, but cell death was induced soon after they reac hed confluency at 39 degrees C. However, cell death was equally preven ted by transfecting the bcl-2 gene. While TGF-beta showed no growth-su ppressive effect in the sensitive and resistant clones at 33 degrees C , it induced significantly earlier cell death in the resistant clones at 39 degrees C. Thus, the resistant clones may be incompletely immort alized cell lines which induce cell death in response to the growth-su ppressive effects of contact inhibition. (C) 1995 Academic Press, Inc.