Studies on functional role of DNA methylation within the FXYD5-COX7A1 region of human chromosome 19.

We used the Rapid Identification of Genomic Splits technique to get a detailed methylation landscape of a 1-megabase-long human genome region (FXYD5-COX7A1, chromosome 19) in normal and tumor lung tissues and in the A549 lung cancer cell line. All three samples were characterized by an essentially uneven density of unmethylated sites along the fragment. Strikingly enough, the distribution of hypomethylated regions did not correlate with gene locations within the fragment. We also demonstrated that the methylation pattern of this long genomic DNA fragment was rather stable and practically unchanged in human lung cancer tissue as compared with its normal counterpart. On the other hand, the methylation landscape obtained for the A549 cell line (human lung carcinoma) in the USF2-MAG locus showed clear differences from that of the tissues mentioned above. A comparative analysis of transcriptional activity of the genes in this region demonstrated the general absence of direct correlation between methylation and expression, although some data suggest a possible role of methylation in the regulation of MAG expression through cis-regulatory elements. In total, our data provide new evidence for the necessity of revising currently prevailing views on the functional significance of methyl groups in genomic DNA.

Fludarabine, low-dose busulfan and antithymocyte globulin as conditioning for Fanconi anemia patients receiving bone marrow transplantation from HLA-compatible related donors.

Allogeneic hematopoietic stem cell transplantation (SCT) from unaffected donors remains the only modality for the correction of hematological abnormalities in Fanconi anemia (FA) patients. We performed four HLA-matched related donor SCT using a novel irradiation and cyclophosphamide-free conditioning regimen. The protocol included fludarabine 150 mg/m(2), busulfan 4 mg/kg, and antithymocyte globulin 90 mg/kg. Graft-versus-host disease (GVHD) prophylaxis was cyclosporin A, MTX, and daclizumab. The engraftment and occurrence of full stable donor hemopoiesis was rapid in all cases with minimal short-term toxic complications. There were no infections or febrile episodes during the inpatient phase. Three patients developed acute GVHD grade I-II involving gut and skin and one patient progressed to extensive chronic GVHD. The preparative conditioning regimen is safe and associated with low organ toxicity and effective immunosupression for the stable engraftment in FA patients undergoing SCT with matched related donors.

Successful treatment of pure red cell aplasia with a single dose of rituximab in a child after major ABO incompatible peripheral blood allogeneic stem cell transplantation for acquired aplastic anemia.

Pure red cell aplasia (PRCA) is a well-known although infrequent hematologic complication after allogeneic bone marrow transplantation. PRCA occurs in cases of major ABO-mismatch between donor and recipient and is believed to be due to inhibition of donor erythroid progenitors by residual host isohemagglutinins. We report a 10-year-old boy with post-hepatitis aplastic anemia (AA) who developed PRCA after HLA-matched familial peripheral blood stem cell transplantation (SCT) following conditioning with Cph 200 mg/kg + ATG 90 mg/kg. Granulocyte engraftment occurred on day +18, platelet engrafted on day +40, while reticulocytopenia at 0% persisted until day +118, and erythroid precursors were totally absent from bone marrow. After a single dose of rituximab 200 mg/m(2)administered on day +118 PRCA resolved and on day +132 the reticulocytes rose to 5.7%. On day +139 the Hb reached 137 g/l and the erythroid lineage in BM increased to 21%. We conclude that due to the rapid recovery from PRCA and lack of side effects, rituximab should be tried as first-line treatment of PRCA after allo-SCT.