Analysis of SDF-1 mRNA and CXCR-4 expression in murine and human cell lines with and without BCR/ABL. (A) The expression of SDF-1 and CXCR-4 mRNA was evaluated by RT-PCR in the murine pre-B cell line Ba/F3, the murine myeloid cell line 32D, and in their BCR/ABL-transformed counterparts. The human erythroleukemia cell line K562 was also evaluated. Primers for β-actin were used to equalize the amount of RT-products used. (B) Immunostaining with antibodies to murine CXCR-4 was performed with the Ba/F3 and Ba/F3.p210^BCR/ABL cell lines (solid histogram). Background staining was determined using a nonspecific isotype matched IgG (clear histogram). Immunostaining with antibodies to human CXCR-4 was performed with the human Mo7e, Mo7e.p210^BCR/ABLmegakaryocytic, and K562 cell lines (solid histogram). Background staining (clear histogram) was determined using a nonspecific isotype matched IgG. (C) Expression of murine CXCR-4 by immunoblotting of protein extracts prepared from Ba/F3, 32D, Mo7e, and their BCR/ABL counterparts. The molecular weight marker of 45 kD is shown and CXCR-4 has an approximate molecular weight of 48 kD.