Related Experiment Video
Updated: Jun 10, 2026
Intra-Peritoneal Transplantation for Generating Acute Myeloid Leukemia in Mice
Published on: January 6, 2023
CD34+ cells from AML with mutated NPM1 harbor cytoplasmic mutated nucleophosmin and generate leukemia in
Maria Paola Martelli1, Valentina Pettirossi, Christian Thiede
1Institute of Hematology and Clinical Immunology, University of Perugia, Perugia, Italy.
Abstract:
Acute myeloid leukemia (AML) with mutated NPM1 shows distinctive biologic and clinical features, including absent/low CD34 expression, the significance of which remains unclear. Therefore, we analyzed CD34(+) cells from 41 NPM1-mutated AML. At flow cytometry, 31 of 41 samples contained less than 10% cells showing low intensity CD34 positivity and variable expression of CD38. Mutational analysis and/or Western blotting of purified CD34(+) cells from 17 patients revealed NPM1-mutated gene and/or protein in all. Immunohistochemistry of trephine bone marrow biopsies and/or flow cytometry proved CD34(+) leukemia cells from NPM1-mutated AML had aberrant nucleophosmin expression in cytoplasm. NPM1-mutated gene and/or protein was also confirmed in a CD34(+) subfraction exhibiting the phenotype (CD34(+)/CD38(-)/CD123(+)/CD33(+)/CD90(-)) of leukemic stem cells. When transplanted into immunocompromised mice, CD34(+) cells generated a leukemia recapitulating, both morphologically and immunohistochemically (aberrant cytoplasmic nucleophosmin, CD34 negativity), the original patient's disease. These results indicate that the CD34(+) fraction in NPM1-mutated AML belongs to the leukemic clone and contains NPM1-mutated cells exhibiting properties typical of leukemia-initiating cells. CD34(-) cells from few cases (2/15) also showed significant leukemia-initiating cell potential in immunocompromised mice. This study provides further evidence that NPM1 mutation is a founder genetic lesion and has potential implications for the cell-of-origin and targeted therapy of NPM1-mutated AML.
Insights
In Acute Myeloid Leukemia (AML) with NPM1 mutations, CD34-positive cells are part of the leukemia clone and act as leukemia-initiating cells. This finding impacts understanding the disease origin and developing targeted therapies.
Area of Science:
- Hematology
- Molecular Biology
- Cancer Research
Background:
- Acute Myeloid Leukemia (AML) with NPM1 mutations presents unique clinical and biological characteristics.
- The role of CD34 expression in NPM1-mutated AML is not fully understood.
- CD34 expression is typically low or absent in NPM1-mutated AML.
Purpose of the Study:
- To investigate the biological and functional significance of CD34 expression in NPM1-mutated AML.
- To determine if CD34-positive cells in NPM1-mutated AML are part of the leukemic clone.
- To identify the leukemia-initiating cell population in NPM1-mutated AML.
Main Methods:
- Flow cytometry analysis of CD34 and other cell surface markers on AML cells.
- Mutational analysis and Western blotting to detect NPM1 mutations in purified CD34+ cells.
- Immunohistochemistry of bone marrow biopsies.
- Xenotransplantation of CD34+ and CD34- cells into immunocompromised mice.
Main Results:
- 31 out of 41 NPM1-mutated AML samples showed low CD34 expression.
- NPM1 mutations were confirmed in CD34+ cells, indicating they belong to the leukemic clone.
- CD34+ cells exhibited a phenotype consistent with leukemic stem cells (CD34+/CD38-/CD123+/CD33+/CD90-).
- Transplantation of CD34+ cells into mice successfully recapitulated the original AML.
- A small fraction of CD34- cells also demonstrated leukemia-initiating potential.
Conclusions:
- The CD34+ fraction in NPM1-mutated AML contains leukemia-initiating cells and is part of the leukemic clone.
- NPM1 mutation is likely a founder genetic event in this AML subtype.
- Findings have implications for understanding the cell of origin and developing targeted therapies for NPM1-mutated AML.
More Related Videos
08:00A Detailed Protocol for Characterizing the Murine C1498 Cell Line and its Associated Leukemia Mouse Model
Published on: October 14, 2016
09:01Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up
Published on: March 26, 2018