Megakaryocytes, malignancy and bone marrow vascular niches


Bethan Psaila, Department of Haematology, Imperial College School of Medicine, Hammersmith Hospital, London W12 OHS, UK.
Tel.: +44 7808 295300; fax: +44 20 8383 1000.


Summary.  Dynamic interactions between hematopoietic cells and their specialized bone marrow microenvironments, namely the vascular and osteoblastic ‘niches’, regulate hematopoiesis. The vascular niche is conducive for thrombopoiesis and megakaryocytes may, in turn, regulate the vascular niche, especially in supporting vascular and hematopoietic regeneration following irradiation or chemotherapy. A role for platelets in tumor growth and metastasis is well established and, more recently, the vascular niche has also been implicated as an area for preferential homing and engraftment of malignant cells. This article aims to provide an overview of the dynamic interactions between cellular and molecular components of the bone marrow vascular niche and the potential role of megakaryocytes in bone marrow malignancy.