Nilotinib Deregulates Cell Cycle Checkpoints, ABC Transporters Genes and JAK-STAT Signaling Pathway of CD34+/Lin- Cells in Chronic-Phase Chronic Myeloid Leukemia (CP-CML) Patients after 12 Months of Treatment

• Published in: Blood 2018-11, Vol.132 (Supplement 1), p.5122-5122
• Main Authors: Trojani, Alessandra, Pungolino, Ester, Rossi, Giuseppe, D'adda, Mariella, Lodola, Milena, Dal Molin, Alessandra, Baruzzo, Giacomo, Perego, Alessandra, Turrini, Mauro, Elena, Chiara, Borin, Lorenza Maria, Iurlo, Alessandra, Malato, Simona, Spina, Francesco, Latargia, Maria Luisa, Spedini, Pierangelo, Artale, Salvatore, Anghilieri, Michela, Maria Cristina, Carraro, Bucelli, Cristina, De Canal, Gabriella, Morra, Enrica, Cairoli, Roberto
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-99-112188

Introduction Chronic myeloid leukemia (CML) is a stem cell disease characterized by the constitutive activity of the oncoprotein BCR-ABL that activates multiple signal transduction pathways. Tyrosine-kinase inhibitor (TKI) nilotinib successfully inhibits the activation and the proliferative function of BCR-ABL in patients with CP-CML. Despite the success of nilotinib, some patients become refractory suggesting the presence of a population of Philadelphia positive (Ph+) quiescent stem cells escaping the drug activity. Thus, the molecular mechanisms underlying CML remain poorly understood. In this study, we enrolled 87 CP-CML patients (Pungolino et. al. Am J Hematol. 2018). Samples were collected on the behalf of the Rete Ematologica Lombarda (REL) the PhilosoPhi34 study (EudraCT: 2012-005062-34), which included 15 centers from Italy. We undertook gene expression profiling (GEP) of selected bone marrow (BM) CD34+/lin- cells of 80 patients at diagnosis vs. the same patients after 12 months of nilotinib to investigate gene expression changes induced by the treatment. Methods We isolated CD34+/lin- cells from BM samples in 87 patients at diagnosis whereas the same cells were also selected from 80/87 patients after 3, 6 and 12 months of nilotinib (Trojani et. al. Cancer Biomark. 2017). BM mononuclear cells (MNCs) as well as BM CD34+/lin- cells of all 80 CML patients were counted at diagnosis and during the treatment with nilotinib (at 3, 6, and 12 months, respectively). Standard FISH tested isolated BM CD34/lin- cells for the 87 patients at diagnosis, and for 80/87 patients after 3, 6 and 12 months of nilotinib treatment, respectively. Therefore, we performed GEP analyses of selected BM CD34+/lin- cells of 80/87 patients at diagnosis vs. the same patients after 12 months of nilotinib treatment. Then, we executed bioinformatic preprocessing and correction for batch effects on raw microarray data. Finally, we conducted differential expression analysis and significantly perturbed genes were subjected to functional clustering. Results We observed a wide variability of the number of BM MNCs as well as the number of the BM CD34+/lin- cells among the 80 CP-CML patients at diagnosis and after 3, 6 and 12 months of nilotinib for each patient (Table 1). Figure 1 showed that the number of the BM CD34+/lin- cells dramatically decreased between the diagnosis and after 3 as well as 6 months of nilotinib. We noticed that the BM CD34+/lin- cells slightly increased between 6 and