medical sciences. For the article “IL-3 receptor signaling is dispensable for BCR-ABL-induced myeloproliferative disease,” by Stephane Wong, Jami McLaughlin, Donghui Cheng, Kevin Shannon, Lorraine Robb, and Owen N. Witte, which appeared in issue 20, September 30, 2003, of Proc. Natl. Acad. Sci. USA (100, 11630-11635; first published September 19, 2003; 10.1073/pnas.2035020100), Figs. 1B and 2A were printed incorrectly due to a printer's error. Also, Fig. 2B middle plot, upper box, should have been labeled “myeloid progenitor,” and the middle plot, lower box, should have been labeled “multipotent progenitor.” The corrected figures and their legends appear below.
Fig. 1.
BCR-ABL expression up-regulates IL-3Rβc/β mRNA levels in ES-derived multipotent and myeloid progenitors. (A) BCR-ABL expression was turned on at day 5 of ES in vitro cell differentiation, and its effects were analyzed on day 7 in nonadherant hematopoietic progenitors by gating and/or sorting for EGFP-positive cells from cultures without tetracycline (TET). Control cells were obtained from +TET cultures. (B) Of a set of 17 different transcription factors, cytokines and their receptors shown to play critical roles in HSC/progenitor, myeloid, and erythroid cell development, the IL-3Rβc/β chains were the only mRNAs up-regulated on BCR-ABL induction in ES-derived hematopoietic progenitors. Similar results were obtained in three sets of independent experiments. (C) BCR-ABL expression elevated IL-3Rβc mRNA levels in ES-derived multipotent and myeloid progenitors. EGFP-positive and -negative multipotent and myeloid progenitors were FACS sorted to >95% purity, and, in two independent experiments, similar RT-PCR results were obtained. MULTI, multipotent; PROG, progenitors.
Fig. 2.
BCR-ABL induces cell surface expression of IL-3Rβc/β in ES-derived hematopoietic cells. (A) BCR-ABL tyrosine kinase activity is required to up-regulate IL-3Rβc/β chain expression in ES-derived hematopoietic progenitors. Imatinib mesylate was added to BCR-ABL cultures at final concentrations of 1 and 10 μM with similar results in triplicate wells. (B) BCR-ABL up-regulates IL-3Rβc/β chain expression in both multipotent and myeloid ES-derived progenitors as defined by cell surface marker analysis. (C) Nine-day induction of BCR-ABL leads to 60-70% of ES-derived hematopoietic cells expressing IL-3Rβc/β chains coincident with low levels of CD11b expression. PE, phycoerythrin.