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1.  Novel mode of action of c-kit tyrosine kinase inhibitors leading to NK cell–dependent antitumor effects 
Journal of Clinical Investigation  2004;114(3):379-388.
Mutant isoforms of the KIT or PDGF receptors expressed by gastrointestinal stromal tumors (GISTs) are considered the therapeutic targets for STI571 (imatinib mesylate; Gleevec), a specific inhibitor of these tyrosine kinase receptors. Case reports of clinical efficacy of Gleevec in GISTs lacking the typical receptor mutations prompted a search for an alternate mode of action. Here we show that Gleevec can act on host DCs to promote NK cell activation. DC-mediated NK cell activation was triggered in vitro and in vivo by treatment of DCs with Gleevec as well as by a loss-of-function mutation of KIT. Therefore, tumors that are refractory to the antiproliferative effects of Gleevec in vitro responded to Gleevec in vivo in an NK cell–dependent manner. Longitudinal studies of Gleevec-treated GIST patients revealed a therapy-induced increase in IFN-γ production by NK cells, correlating with an enhanced antitumor response. These data point to a novel mode of antitumor action for Gleevec.
doi:10.1172/JCI200421102
PMCID: PMC489961  PMID: 15286804
2.  Inflammatory breast cancer: Vasculogenic mimicry and its hemodynamics of an inflammatory breast cancer xenograft model 
Breast Cancer Research  2003;5(3):136-139.
We recently established a new human inflammatory breast cancer (IBC) xenograft (WIBC-9) originating from a patient with IBC. The original tumor and WIBC-9 revealed invasive ductal carcinoma with a hypervascular structure of solid nests and marked lymphatic permeation in the overlying dermis. In the central part of the solid nests, vasculogenic mimicry, which showed an absence of endothelial cells, was observed. Comparison of WIBC-9 with an established non-IBC xenograft (MC-5), using time-course dynamic micro-magnetic resonance angiography analysis (with a newly developed intravascular macromolecular contrast agent for magnetic resonance imaging) demonstrated that the WIBC-9 tumor had blood flow and a vascular mimicry–angiogenesis junction.
PMCID: PMC165001  PMID: 12793894
hemodynamics; inflammatory breast cancer; vasculogenic mimicry; xenograft model
3.  Dendritic Cell Maturation Overrules H-2d–Mediated Natural Killer T (Nkt) Cell Inhibition 
The Journal of Experimental Medicine  2001;194(8):1179-1186.
Given the broad expression of H-2 class Ib molecules on hematopoietic cells, antigen presentation pathways among CD1d expressing cells might tightly regulate CD1d-restricted natural killer T (NKT) cells. Bone marrow–derived dendritic cells (BM-DCs) and not adherent splenocytes become capable of triggering NK1.1+/T cell receptor (TCR)int hepatic NKT cell activation when (a) immature BM-DCs lack H-2Db−/− molecules or (b) BM-DCs undergo a stress signal of activation. In such conditions, BM-DCs promote T helper type 1 predominant CD1d-restricted NKT cell stimulation. H-2 class Ia–mediated inhibition involves more the direct H-2Db presentation than the indirect Qa-1b pathway. Such inhibition can be overruled by B7/CD28 interactions and marginally by CD40/CD40L or interleukin 12. These data point to a unique regulatory role of DCs in NKT cell innate immune responses and suggest that H-2 class Ia and Ib pathways differentially control NKT cell recognition of DC antigens.
PMCID: PMC2193518  PMID: 11602646
inhibitory receptors; IFN-γ; costimulation; CD1d; NKT cells

Results 1-3 (3)