Monoclonal antibodies directed against tumor antigens have proven effective for treating some forms of cancer. Despite the increasing use of monoclonal antibody therapy, it is not clear how these antibodies drive tumor removal.
In this issue of the Journal of Clinical Investigation, Marjolein van Egmond and colleagues at the VU University Medical Center found that macrophage populations mediate tumor cell removal following monoclonal antibody treatment by actively phagocytosing tumor cells.
Macrophage-dependent tumor cell removal required both the high affinity and low affinity Fc receptors. This study suggests that monoclonal antibody therapies that are optimized to enhance macrophage recruitment and activity may enhance removal of circulating tumor cells in cancer patients.
TITLE: Macrophages eliminate circulating tumor cells after monoclonal antibody therapy
View this article at: http://www.jci.org/articles/view/66776?key=5bbe1c588bfc574caed3
Targeting a cell cycle inhibitor promotes β cell replication
One of the factors underlying the development of type 2 diabetes is loss of β cell mass, resulting in decreased insulin production. Once lost, β cell mass cannot be restored. In contrast, infants with focal hyperinsulinism of infancy exhibit rapid expansion of the β cell mass due to a silencing of a region of chromosome 11 that includes the gene encoding the cell cycle inhibitor p57Kip2.
In this issue of the Journal of Clinical Investigation, Klaus Kaestner and colleagues at the University of Pennsylvania demonstrate that silencing the gene encoding p57Kip2 in isolated adult human islets promotes β cell replication and that these new cells exhibit many properties associated with β cells.
This study provides an explanation for excessive β cell expansion in children with focal hyperinsulinism and suggests that targeting the p57Kip2 pathway in adults with type 2 diabetes may improve β cell function.
TITLE: Targeting the cell cycle inhibitor p57Kip2 promotes adult human β cell replication
View this article at: http://www.jci.org/articles/view/69519?key=5ed5fc651e71db738504