Fig. 3. Down-regulation of T-STAR in SV40-transformed immortal cells and tumor cell lines. A, T-STAR expression was examined in preimmortal and immortal cells of various SV40 transformed fibroblasts (9) . B, a probe recognizing the Sam68 mRNA was hybridized to a filter containing the same samples as in A to examine Sam68 expression. C, cell lines from the four different complementation groups were examined for T-STAR expression: HeLa, a cervical carcinoma cell line (complementation group B); A1698, a bladder carcinoma cell line (complementation group D); EJ, also a bladder carcinoma cell line (complementation group A); and CMV-Mj-HEL1, a cytomegalovirus-transformed fibroblast cell line (complementation group C). These cell lines were taken as representatives of the complementation groups (20) . RNA samples of VH10/SV pre- and postcrisis cells were loaded as controls. A probe recognizing GAPDH was used as a control for equal loading.