Establishment of a Novel CD34+ Hematopoietic Stem Cell-derived Xenograft Model of Hyperleukocytic Acute Myeloid Leukemia

Abstract

BackgroundHyperleukocytic acute myeloid leukemia (HLL) with high early mortality is difficult to therapy. The related research on HLL is still in its infancy, and the establishment of a patient derived xenograft (PDX) model of HLL has not been fully reported, especially the CD34+ hematopoietic stem cell-derived xenograft model of HLL. MethodsUsing the routine blood examination, smear analysis and bone marrow biopsy, flow cytometry, mutation analysis to evaluate the establishment of HLL model. And the correlation between the survival time in mice and in patients was analyzed by a linear regression model with variable selection “entered” with SPSS software.ResultsOur findings demonstrated that the leukocyte counts reached up to 37.35Í109/l, and the immunophenotypes of hCD45+, hCD15+ and hCD33+ cells were detected in peripheral blood (PB) and bone marrow (BM) after inoculation with cells derived from PB for establishment of the HLL PDX model. The same results were demonstrated after inoculation with cells derived from BM of the patient. For the CD34+ hematopoietic stem cell derived xenograft model, the CD34+ hematopoietic stem cells more severely infiltrated the BM, liver and spleen. More importantly, human WT1 and NRAS mutants were detected in the liver, spleen and BM of the mouse. By performing a comparative analysis of multiple experiments, we found that mice receiving a higher irradiation dose of 2.5 Gy and higher injected cell counts derived from PB exhibited a shorter survival time. Furthermore, the constructed model mice injected with NRAS, DNMT3A, FLT3, or NMPM1 gene mutations had shorter survival times. The correlation analysis showed that the survival time in mice was significantly related with the survival status of the enrolled patients. ConclusionsWe successfully established a novel CD34+ hematopoietic stem cell-derived xenograft model of HLL, which shows great promise for mechanistic research, drug screening, individualized therapy, clinical efficacy assessment and precision medicine in HLL.