Neonatal expression of RNA-binding protein IGF2BP3 regulates the human fetal-adult megakaryocyte transition.

Hematopoietic transitions that accompany fetal development, such as erythroid globin chain switching, play important roles in normal physiology and disease development. In the megakaryocyte lineage, human fetal progenitors do not execute the adult morphogenesis program of enlargement, polyploidization, and proplatelet formation. Although these defects decline with gestational stage, they remain sufficiently severe at birth to predispose newborns to thrombocytopenia.

Developmental differences in megakaryocyte size in infants and children.

Developmental differences in megakaryocytes between neonates and adults have been described. However, the age at which megakaryocytes make a transition to an adult phenotype is unknown. Small megakaryocytes are often described as "dysplastic" in the pathology literature.

HLA-DR protein status predicts survival in patients with diffuse large B-cell lymphoma treated on the MACOP-B chemotherapy regimen.

Loss of major histocompatibility class II (MHC class II) molecules on diffuse large B-cell lymphoma (DLBCL) has been associated with poor survival; however, none of these reports analysed a uniformly treated patient cohort. This study was designed to validate one MHC class II antigen, HLA-DR, as a prognostic marker in patients uniformly treated with the MACOP-B regimen. Immunostaining results were correlated with the international prognostic index (IPI) score and overall survival (OS).

Stem cell transplantation demonstrates that Sox6 represses epsilon y globin expression in definitive erythropoiesis of adult mice.

Sox6, a member of the Sox transcription factor family, is essential for the silencing of epsilon y globin gene expression in definitive erythropoiesis of mice. Homozygous Sox6-null mice are neonatally lethal, precluding analysis at later stages. We created adult mice that are deficient in Sox6 specifically in hematopoietic tissues by transplanting embryonic liver stem cells from Sox6-deficient mice into lethally irradiated congenic wild-type adult mice.

Disseminated extramedullary myeloid tumor of the gallbladder without involvement of the bone marrow.

Extramedullary myeloid tumors (myeloid sarcomas) are rare neoplasms that are composed of myeloid precursors. They usually arise concurrently with a diagnosis of acute myeloid leukemia, chronic myeloid leukemia, or other myeloproliferative disorders. They may also indicate relapsing disease in a patient with a prior history of leukemia or myeloproliferative disorder.

Sox6 directly silences epsilon globin expression in definitive erythropoiesis.

Sox6 is a member of the Sox transcription factor family that is defined by the conserved high mobility group (HMG) DNA binding domain, first described in the testis determining gene, Sry. Previous studies have suggested that Sox6 plays a role in the development of the central nervous system, cartilage, and muscle. In the Sox6-deficient mouse, p100H, epsilony globin is persistently expressed, and increased numbers of nucleated red cells are present in the fetal circulation.

Loss of MHC class II gene and protein expression in diffuse large B-cell lymphoma is related to decreased tumor immunosurveillance and poor patient survival regardless of other prognostic factors: a follow-up study from the Leukemia and Lymphoma Molecular Profiling Project.

The Leukemia and Lymphoma Molecular Profiling Project recently published results from DNA microarray analyses of 240 diffuse large B-cell lymphomas (DLBCLs). Four gene expression "signatures" were identified as correlated with patient outcome, including the major histocompatibility complex (MHC) class II genes (eg, HLA-DRA) which correlated with better survival. We further analyzed the effects of HLA-DRA on survival and correlated gene expression with protein status and tumor-infiltrating lymphocytes.