cyclic-gmp and Myelodysplastic-Syndromes

RNA helicases are involved in almost every aspect of RNA, from transcription to RNA decay. DExD/H-box helicases comprise the largest SF2 helicase superfamily, which are characterized by two conserved RecA-like domains. In recent years, an increasing number of unexpected functions of these proteins have been discovered. They play important roles not only in innate immune response but also in diseases like cancers and chronic hepatitis C. In this review, we summarize the recent literatures on one member of the SF2 superfamily, the DEAD-box protein DDX41. After bacterial or viral infection, DNA or cyclic-di-GMP is released to cells. After phosphorylation of Tyr414 by BTK kinase, DDX41 will act as a sensor to recognize the invaders, followed by induction of type I interferons (IFN). After the immune response, DDX41 is degraded by the E3 ligase TRIM21, using Lys9 and Lys115 of DDX41 as the ubiquitination sites. Besides the roles in innate immunity, DDX41 is also related to diseases. An increasing number of both inherited and acquired mutations in DDX41 gene are identified from myelodysplastic syndrome and/or acute myeloid leukemia (MDS/AML) patients. The review focuses on DDX41, as well as its homolog Abstrakt in Drosophila, which is important for survival at all stages throughout the life cycle of the fly.

Topics: Agammaglobulinaemia Tyrosine Kinase; Animals; Bacterial Infections; Cyclic GMP; DEAD-box RNA Helicases; Drosophila melanogaster; Drosophila Proteins; Humans; Leukemia, Myeloid, Acute; Mutation; Myelodysplastic Syndromes; Nuclear Proteins; Protein-Tyrosine Kinases; Virus Diseases

This study was performed to investigate whether measurement of cyclic GMP (cGMP), a marker for nitric oxide production, before and after allogeneic bone marrow transplantation (BMT) with total body irradiation (TBI) conditioning was of prognostic value. cGMP levels were monitored in 23 consecutive patients who received TBI as conditioning for BMT, and were compared with the outcome. cGMP became positive during the aplastic phase after BMT in 12 patients. In nine of these 12 patients, cGMP level decreased during the recovery phase. Eight of the nine patients survived, one dying after relapse. In three other patients, the cGMP level continued to increase even during the recovery phase and they died of severe complications. cGMP became positive on day 0 of BMT and during the leukocyte recovery phase after BMT in two and seven of the 23 patients, respectively. Subsequently, all patients died of severe complications. The two patients who were negative for cGMP both before and after BMT survived without complications. These results suggest that monitoring cGMP from early after BMT may be useful for predicting outcome and that it may be a useful prognostic marker.

Topics: Adolescent; Adult; Biomarkers; Blast Crisis; Bone Marrow Transplantation; Cyclic GMP; Cyclosporine; Drug Therapy, Combination; Female; Graft vs Host Disease; Humans; Immunosuppressive Agents; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid, Acute; Male; Methotrexate; Methylprednisolone; Monitoring, Physiologic; Myelodysplastic Syndromes; Neoplasm Staging; Nitric Oxide; Prognosis; Transplantation Conditioning; Transplantation, Homologous; Treatment Outcome; Whole-Body Irradiation