Leukemia and cell adhesion mediated-drug resistance (CAM-DR)
Leukemia is a cancer originated in the bone marrow characterized by an abnormal proliferation of cells derived from the hematopoietic system. The disease is characterized by the presence of genetically altered progenitor cells and is primary classified according to their myeloid or lymphoid origin. Moreover, the potential to undergo differentiation is critical for the definition of leukemias as acute or chronic. In all cases, the development of hematological malignancies depends on both intrinsic and extrinsic properties. In the last decade, the interaction of leukemic cells with their microenvironment in the bone marrow has gained increasing attention. The so called niche mentioned above, which has been well described to regulate the fate of normal hematopoietic stem cells (HSC) may also confer resistance to leukemic cells against chemotherapeutic agents and radiation. All three niche components; cell-cell contact, soluble factors and CM, have been described as anti-apoptotic factors for leukemic cells. However, most in vivo findings highlight the role of direct cell-cell or cell-ECM contact between BMSC and leukemic cells, a phenomenon commonly referred as cell adhesion mediated drug resistance (CAM-DR).