Gene expression changes induced in the stromal cell line EL08-1D2 by co-culture with leukemic B cells (CLL)

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-βII and the subsequent activation of NF-κB in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC-β knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-βII- NF-κB signaling pathway in the tumor microenvironment. Upregulated stromal PKC-βII in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies. We used microarrays to determine gene expression changes induced by co-culturing with leukemic B-cells (CLL) in EL08-1D2 cells. We compared EL08-1D2 cells co-cultured for 5 days with leukemic B-cells to EL08-1D2 mono-cultured cells by microarray analysis on Affymetrix MG-430_2.0 arrays.