Tel/PDGFRβ inhibits self-renewal and directs myelomonocytic differentiation of ES cells

DifferentialHoxExpression in Murine Embryonic Stem Cell Models of Normal and Malignant Hematopoiesis

“…The t(5:12)(q33;p13) translocation, identified in a subset of patients with the MPN chronic myelomonocytic leukemia, fuses an Ets-related transcription factor (Tel) to the PDGFRb gene, producing the Tel=PDGFRb (TP) tyrosine kinase-active fusion protein [22]. Previous studies using tetracycline (Tet)-regulated expression of TP recapitulated observed findings for TP þ patient samples, in particular alterations in the hematopoietic transcriptional network that drives myelomonocytic differentiation [23,24]. In this study, we have employed a previously established hematopoietic differentiation model [5] to determine the Hox transcriptional profile during primitive and more definitive hematopoietic commitment.…”

“…4B and ref. [24]) and decreased ES cell self-renewal and proliferation as verified by reduced alkaline phosphatase staining (Fig. 4C).…”

“…The ES-TP clones were cultured as previously described [24]. For induction of expression of TP clones were washed Â3 with PBS and incubated in LIF-containing media in the presence of 500 ng=mL Tet to prevent expression of TP, or no Tet to induce the expression of TP.…”

“…Cells were cultured with and without Tet for 24, 48, or 72 h to induce the short-term expression of TP. After treatment, the cells were harvested and washed Â3 with ice-cold PBS before being lysed as described previously [24]. Protein concentrations were determined using a Bio-Rad protein assay kit.…”

“…Previous studies investigating the role of TP during hematopoietic differentiation of ES cells indicated that this oncogene can upregulate several transcription factors involved in regulating HSC expansion, including Hoxb4 and Cdx4 [24]. Several studies have shown that the Cdx family are global regulators of Hox gene expression.…”