Transcriptome analysis of blast Side and Main populations cells in patients with acute myeloid leukemia

Acute myeloid leukemia (AML) represent a series of hemopathies characterized by the clonal expansion in bone marrow and blood of immature myeloid cells blocked in differentiation, called blasts. Despite significant supportive care progresses, few medical discoveries radically changed LAM prognosis (5 year survival rate of 30%). An aggressive conventional chemotherapy is used to kill AML cells. However, many patients relapse mainly due to the persistence of rare AML cells able to re-initiate the disease. Quiescence and protection against environmental stresses (chemoresistance) are major characteristics of these cells. Drug efflux leading to chemoresistance is observed by Side Population (SP) detection through ABC transporter activation. So, AML blasts presenting SP functionality could represent a chemoresistant population. This SP phenotype is essentially acquired by circulating AML blasts after contact with medullar mesenchymal stromal cells (MSC). A transcriptome analysis of AML blasts sorted according to their SP functionality or not (Non SP cells or Main Population, ie MP) after co-culture on MSCs was realized. Transcriptome analysis was performed on Side population (SP) AML blasts versus Non Side population (NSP) AML blasts, also named main population (MP). Cells were sorted after a 3-day co-culture of peripheral blood AML blast sample at diagnosis with human medullar mesenchymal stromal cells.