Expression of recombinant Rh and RhAG transcripts under the control of CMV promoter is enhanced by TPA treatment of transfected K562 cells.

Northern blot analyses were performed with RNA samples from K562 cells and K562/RhAG, K562/RhD, and K562/Lu cells stably expressing RhAG, RhD, and Lu proteins, respectively. Total RNAs were extracted from TPA-untreated cells (0) and from transfected cells preliminarily treated with TPA for 24 and 48 hours (24 and 48). Lu, Rh, and RhAG probes were prepared and labeled as described in “Materials and methods.” Blots were exposed to Kodak BioMax MS film for 4 hours. On longer exposure, the endogenous Rh and RhAG transcripts were detected from K562 untransfected and transfected cells (not shown).