Description
Tumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here we describe a novel survival signaling pathway activated in stromal cells by contact to B-cells from chronic lymphocytic leukemia (CLL) patients. The expression of PKC-II and the subsequent activation of NF-B in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC- knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-II- NF-B signaling pathway in the tumor microenvironment. Upregulated stromal PKC-II in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies.