This proposal will investigate the mechanisms by which Fanconi anemia (FA) proteins regulate cellular response to oxidative stress in the context of hematopoiesis. The process of FA disease progression is characterized by bone marrow failure (BMF), clonal proliferation of hematopoietic stem and progenitor (HSC/P) cells, and progression to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). While clinical observations have established a correlation between abnormal accumulation of ROS and FA BMF/leukemic evolution, the molecular pathways in which FA proteins function to modulate physiologic oxidative stress have not been defined. We recently found that FA BM cells accumulated high levels of ROS generated by inflammation and that FA HSC/P cells were extremely sensitive to ROS-induced hematopoietic suppression. We have also shown that abnormal accumulation of ROS played a critical role in the evolution of leukemic clones in FA mouse model. Our most recent identification of the FANCD2- FOXO3a complex and preliminary characterization of impaired anti-oxidant defense in primary BM cells from FA patients open new research opportunities to extend this project to the renewal period.
In Aim 1, we will test the hypothesis that physiologic oxidative stress contributes to BMF and progression to clonal hematopoiesis in FA through influencing HSC/P cell proliferation and apoptosis, by assessing the effect of inflammatory ROS on proliferation and apoptosis of HSC/P cells from FA children at three different stages (BMF, MDS, and AML) of disease progression and in a "humanized" NOG/SGM3 mouse xenograft model.
In Aim 2, we will test the hypothesis that functional interaction between the FA proteins and other cell signaling pathways play important roles in maintaining normal hematopoiesis under physiologic oxidative stress, with focus on major oxidative stress response pathways involving FOXO3a and cellular anti-oxidant defense systems.
In Aim 3, we will test the hypothesis that increased inflammatory ROS and vulnerability of chromosomal DNA to oxidative damage would provide a potential genetic mechanism for FA genomic instability, with focus on the roles of FA proteins in oxidative DNA-damage response and repair, and the functional relationship between inflammatory ROS and genomic instability during FA leukemogenesis using two FA preleukemic models. The knowledge gained from these studies may lead to a new avenue of research designed to further explore the pathogenic role of oxidative stress not only in FA but also in cancer- related hematological diseases in general. In addition, new insights on the potential integration of the FA proteins in other oxidative-stress signaling pathways can suggest new targets for therapeutic prevention and treatment of BMF and cancer progression of these diseases.
Oxidative stress has been implicated in the pathogenesis of many human diseases including Fanconi anemia (FA), a blood disease associated with bone marrow failure and cancer. The goal of this project is to define the function of FA proteins in the maintenance of blood cell survival under physiologic oxidative stress. The proposed study will provide valuable information for therapeutic prevention and treatment of bone marrow failure and cancer progression of not only FA but also other blood diseases.
|Guo, F; Li, J; Zhang, S et al. (2014) mTOR kinase inhibitor sensitizes T-cell lymphoblastic leukemia for chemotherapy-induced DNA damage via suppressing FANCD2 expression. Leukemia 28:203-6|
|Du, Wei; Erden, Ozlem; Wilson, Andrew et al. (2014) Deletion of Fanca or Fancd2 dysregulates Treg in mice. Blood 123:1938-47|
|Li, Jie; Pang, Qishen (2014) Oxidative stress-associated protein tyrosine kinases and phosphatases in Fanconi anemia. Antioxid Redox Signal 20:2290-301|
|Du, Wei; Erden, Ozlem; Pang, Qishen (2014) TNF-* signaling in Fanconi anemia. Blood Cells Mol Dis 52:2-11|
|Guo, F; Li, J; Du, W et al. (2013) mTOR regulates DNA damage response through NF-*B-mediated FANCD2 pathway in hematopoietic cells. Leukemia 27:2040-6|
|Du, Wei; Amarachintha, Surya; Sipple, Jared et al. (2013) Inflammation-mediated notch signaling skews fanconi anemia hematopoietic stem cell differentiation. J Immunol 191:2806-17|
|Du, Wei; Rani, Reena; Sipple, Jared et al. (2012) The FA pathway counteracts oxidative stress through selective protection of antioxidant defense gene promoters. Blood 119:4142-51|
|Ali, Abdullah Mahmood; Pradhan, Arun; Singh, Thiyam Ramsingh et al. (2012) FAAP20: a novel ubiquitin-binding FA nuclear core-complex protein required for functional integrity of the FA-BRCA DNA repair pathway. Blood 119:3285-94|
|Li, Xue; Sipple, Jared; Pang, Qishen et al. (2012) Salidroside stimulates DNA repair enzyme Parp-1 activity in mouse HSC maintenance. Blood 119:4162-73|
|Du, Wei; Li, Xu-E; Sipple, Jared et al. (2011) Overexpression of IL-3R* on CD34+CD38- stem cells defines leukemia-initiating cells in Fanconi anemia AML. Blood 117:4243-52|
Showing the most recent 10 out of 23 publications