In this exploratory project, we are proposing to develop a new strategy to overcome radiation resistance of leukemic stem cells in B-lineage ALL using a novel recombinant biotherapeutic agent, namely CD19-Ligand, for selectively amplifying radiation-induced pro-apoptotic signaling. The long-term goal of the proposed research is to establish """"""""personalized"""""""" radiation therapy regimens against relapsed B-lineage ALL employing a recombinant biotherapeutic agent to selectively increase the anti-leukemic potency of ionizing radiation. We hypothesize that the treatment outcome of relapsed B-lineage ALL patients can be improved by using recombinant CD19-Ligand in combination with TBI in the context of HSCT.
Under Specific Aim 1, we will examine the effects of recombinant CD19-L on in vitro radiation resistance of radiation-resistant ALL cell lines as well as primary ALL cells from relapsed B-lineage ALL patients using quantitative flow cytometric apoptosis assays and clonogenic assays (Year 1 of the Project). We hypothesize that CD19-L will amplify radiation- induced pro-apoptotic BTK signals thereby markedly and selectively enhancing radiation-induced apoptosis of CD19+ B-lineage ALL cells as well as augmenting radiation-induced death of their clonogenic fraction. The radiation resistance of leukemic cells will be measured using our standard quantitative flow cytometric (CD19/Annexin V staining) and confocal (TUNEL) apoptosis assay platforms.
Under Specific Aim 2, we will examine the effects of the CD19-L on in vivo radiation resistance of leukemic stem cells in primary bone marrow specimens from relapsed B-lineage ALL patients using SCID mouse xenograft models of relapsed B- lineage ALL and sublethal TBI (Year 2 of the Project). We anticipate that the use of CD19-L before and concomitant with radiation will markedly enhance the anti-leukemic potency of TBI in the context of HSCT. Likewise, the sequential administration of TBI and post-TBI CD19-L is expected to be more effective than TBI alone. We will first perform mouse toxicity and pharmacokinetics experiments to determine non-toxic dose levels of CD19-L and then examine the effects of CD19-L on the anti-leukemic potency of sublethal TBI (2 Gy) against leukemic stem cells in primary bone marrow specimens from relapsed patients as well as radiation- resistant B-lineage ALL cell lines in a SCID mouse xenograft model system. Our working hypothesis is that CD19-L plus TBI regimens will be more effective than TBI alone in improving the event-free survival outcome of SCID mice challenged with primary B-lineage ALL cells. We anticipate that the successful completion of this exploratory research project will provide the first preclinical proof-of-principle for a potentially paradigm-shifting therapeutic innovation against relapsed B-lineage ALL, whereby the radiation resistance of leukemic stem cells is overcome using recombinant CD19-L as a selective radiosensitizer that amplifies pro-apoptotic signaling after radiation.

Public Health Relevance

Currently, the major challenge in the treatment of childhood leukemia is to cure patients who experience a recurrence of their cancer despite intensive chemotherapy. The purpose of the proposed research is the development of an effective treatment

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21CA164098-01
Application #
8224131
Study Section
Radiation Therapeutics and Biology Study Section (RTB)
Program Officer
Bernhard, Eric J
Project Start
2012-07-06
Project End
2014-06-30
Budget Start
2012-07-06
Budget End
2013-06-30
Support Year
1
Fiscal Year
2012
Total Cost
$211,410
Indirect Cost
$80,910
Name
Children's Hospital of Los Angeles
Department
Type
DUNS #
052277936
City
Los Angeles
State
CA
Country
United States
Zip Code
90027
Uckun, Fatih M; Myers, Dorothea E; Cheng, Jianjun et al. (2015) Liposomal Nanoparticles of a Spleen Tyrosine Kinase P-Site Inhibitor Amplify the Potency of Low Dose Total Body Irradiation Against Aggressive B-Precursor Leukemia and Yield Superior Survival Outcomes in Mice. EBioMedicine 2:554-62
Uckun, Fatih M; Myers, Dorothea E; Ma, Hong et al. (2015) Low Dose Total Body Irradiation Combined With Recombinant CD19-Ligand × Soluble TRAIL Fusion Protein is Highly Effective Against Radiation-Resistant B-Precursor Acute Lymphoblastic Leukemia in Mice. EBioMedicine 2:306-316
Uckun, Fatih M; Mitchell, Lloyd G; Qazi, Sanjive et al. (2015) Development of Polypeptide-based Nanoparticles for Non-viral Delivery of CD22 RNA Trans-splicing Molecule as a New Precision Medicine Candidate Against B-lineage ALL. EBioMedicine 2:649-59
Uckun, Fatih M; Myers, Dorothea E; Qazi, Sanjive et al. (2015) Recombinant human CD19L-sTRAIL effectively targets B cell precursor acute lymphoblastic leukemia. J Clin Invest 125:1006-18
Myers, Dorothea E; Yiv, Seang; Qazi, Sanjive et al. (2014) CD19-antigen specific nanoscale liposomal formulation of a SYK P-site inhibitor causes apoptotic destruction of human B-precursor leukemia cells. Integr Biol (Camb) 6:766-80
Uckun, Fatih M; Qazi, Sanjive; Dibirdik, Ilker et al. (2013) Rational design of an immunoconjugate for selective knock-down of leukemia-specific E2A-PBX1 fusion gene expression in human Pre-B leukemia. Integr Biol (Camb) 5:122-32
Qazi, Sanjive; Ma, Hong; Uckun, Fatih M (2013) Absence of Genomic Ikaros/IKZF1 Deletions in Pediatric B-Precursor Acute Lymphoblastic Leukemia. Int J Mol Med Sci 3:72-82
Uckun, Fatih M; Qazi, Sanjive; Cely, Ingrid et al. (2013) Nanoscale liposomal formulation of a SYK P-site inhibitor against B-precursor leukemia. Blood 121:4348-54
D'Cruz, Osmond J; Uckun, Fatih M (2013) Protein kinase inhibitors against malignant lymphoma. Expert Opin Pharmacother 14:707-21
Ozer, Zahide; Qazi, Sanjive; Ishkhanian, Rita et al. (2013) KU HAPLOINSUFFIENCY CAUSES A LYMPHOPROLIFERATIVE DISORDER OF IMMATURE T-CELL PRECURSORS DUE TO IKAROS MALFUNCTION. Int J Mol Med Sci 3:50-64

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