The World Health Organization Classification of Lymphoid Neoplasms identifies Burkitt lymphoma/leukemia as a highly aggressive mature B-cell neoplasm consisting of endemic, sporadic, and immunodeficiency-associated variants. These subtypes share many morphologic and immunophenotypic features, but differences exist in their clinical and geographic presentations. All of these subtypes possess chromosomal rearrangements of the c-myc oncogene, the genetic hallmark of Burkitt lymphoma that contributes to lymphomagenesis through alterations in cell cycle regulation, cellular differentiation, apoptosis, cellular adhesion, and metabolism. Brief-duration, high-intensity chemotherapy regimens containing aggressive central nervous system prophylaxis have had remarkable success in the treatment of this disease, with complete remission rates of 75% to 90% and overall survivals reaching 50% to 70% in adults. Although Burkitt lymphoma cells are extremely chemosensitive, biologically targeted therapies should be developed because current treatment options are suboptimal for patients with poor prognostic features or in the setting of relapsed disease. (Blood.

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Acute graft-versus-host disease (aGVHD) remains a major complication of allogeneic hematopoietic stem cell transplant (alloHSCT), underscoring the need to further elucidate its mechanisms and develop novel treatments. Based on recent observations that microRNA-155 (miR-155) is up-regulated during T-cell activation, we hypothesized that miR-155 is involved in the modulation of aGVHD.Here we show that miR-155 expression was up-regulated in T cells from mice developing aGVHD after alloHSCT. Mice receiving miR-155-deficient donor lymphocytes had markedly reduced lethal aGVHD, whereas lethal aGVHD developed rapidly in mice recipients of miR-155 overexpressing T cells. Blocking miR-155 expression using a synthetic antimiR-155 after alloHSCT decreased aGVHD severity and prolonged survival in mice. Finally, miR-155 up-regulation was shown in specimens from patients with pathologic evidence of intestinal aGVHD. Altogether, our data indicate a role for miR-155 in the regulation of GVHD and point to miR-155 as a novel target for therapeutic intervention in this disease.

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Renal medullary carcinoma is an aggressive, chemoresistant tumor. Time from discovery of tumor to patient death is very short and has been altered by a wide variety of chemotherapies and immunotherapies. An unidentified genetic component is likely present.