The transformation of BHK 21 hamster cells by simian virus 40

Abstract

Abstract Although BHK 21 cells remain refractory to direct transformation by SV40 virus even at multiplicities of infection as high as 10 4 PFU per cell, transformed derivatives may be produced by cocultivation of the untransformed cells with monkey cells infected with SV40 virus. The characteristics of a cloned SV40‐transformed line (C13/SV) have been studied. The cells showed several of the properties of BHK 21 cells transformed by other oncogenic viruses. High‐passage variants of the line (C13/SV‐M) metastasized from the primary tumour that they induced in hamsters. Metastatic foci were the result of dissemination of the cells, and not due to the release of infectious SV40 virus from implanted cells. Comparisons between the in vitro and in vivo growth properties of C13/SV and C13/SV‐M cells did not reveal a correlation with metastasizing ability. The C13/SV‐M cells also retained those properties of transformed cells that are probably associated with surface alterations, although the SV40‐specific transplantation antigen may be partially absent or masked in these cells.