Chemotherapy can be an effective treatment for acute myeloid leukemia (AML) but many patients relapse to develop resistance to the treatment which can be due to leukemic stem cells – cancer stem cells that give rise to the leukemic cells that invade the bone marrow and affect the production of healthy blood cells.
Myeloid blast cells in the bone marrow normally mature and give rise to white blood cells such as neutrophils, eosinophils, basophils and monocytes, and macrophages. AML arises from the overactivity of abnormal myeloid blast cells. These abnormal blast cells build up in the bone marrow and stop the production of healthy blood cells. The rapidly growing cells slop the production of normal blood cells.
While leukemic stem cells are known to exist, it can be difficult to isolate and target the cells as there are no known markers; however, a team of researchers at the Functional Cytomics Research Group at the Josep Carreras Leukaemia Research Institute have developed a technique that allows the cells to be identified through the activity of a protein called alkaline phosphatase.
Alkaline phosphatase is present in myeloblasts. It is expressed at low levels n somatic cells but high levels in primitive stem cells. The researchers hypothesized that there may be differences in alkaline phosphatase activity in leukemic stem cells., which could correspond to a risk of recurrence and mortality in patients diagnosed with AML.
The researchers used advanced cytomical techniques that allowed them to analyze multiple characteristics of single cells quickly. The analysis of each cell takes just a few minutes. In a prospective hospital-based cohort of 43 newly diagnosed patients with AML, the activity of alkaline phosphatase was measured. The researchers found the levels of alkaline phosphatase activity in patients with AML corresponded with their response to chemotherapy. Patients with low levels of alkaline phosphatase activity responded well to chemotherapy and patients with high levels of alkaline phosphatase activity did not respond well to treatment and had poor survival rates.
“These results represent a new approach to improve the prognosis in the diagnostic evaluation of acute myeloid leukemia and to estimate the probability of relapse and persistence of the disease. This will allow us to open new lines of research aimed at applying alternative strategies in terms of treatment,” said study director, Dr. Jordi Petriz.
You can read more about the study in the paper – Flow cytometric significance of cellular alkaline phosphatase activity in acute myeloid leukemia – which was recently published in the journal Oncotarget. DOI: 10.18632/oncotarget.27356