FIG. 5.

Quiescent human cells remain viable after silencing of p60. (A) Transfections of quiescent human EJ30 cells were performed at 10 days after serum deprivation. Western blot analysis of whole-cell extracts prepared at 48 h posttransfection with nontarget (nt) and p60 siRNAs was performed. The untransfected cell extract control is also shown (−). Equal protein amounts were loaded and probed with polyclonal antibodies specific for p60 (22) and replication protein A (RPA) (38); only the RPA-32 band is shown. (B) Cell viability was determined in these quiescent cells at 48 h posttransfection, as detailed in the legend to Fig. 2A. (C) Direct visualization of these cells by phase-contrast light microscopy, as detailed in the legend to Fig. 2B.