Expression of p35 and p39 in SAOS-2 and U2OS cells. A, RT-PCR for p35 and p39 from the total RNA of SAOS-2 and U2OS cells. Lane -RT, negative control using RNA without reverse transcription. B, SAOS-2 and U2OS cells were treated with MG132 (20 μm) for 16 h before harvest, whole cell extracts (30 μg of protein per lane) were analyzed by immunoblotting with anti-p35 antibody, the ectopically expressed p35 was used as positive control.