Genomic profiling of enzastaurin-treated B cell lymphoma RL cells

Follicular lymphoma (FL) is an indolent lymphoma associated with follicular center B cells, and typically contains the Bcl-2 chromosomal translocation t(14;18), which leads to overexpression of the anti-apoptotic intracellular protein Bcl-2. FLs are sensitive to chemotherapy; however, patient relapses occur and response duration becomes progressively shorter, with the majority of patients eventually dying from the disease. Enzastaurin (LY317615), an acyclic bisindolylmaleimide, was initially developed as an ATP-competitive selective inhibitor of PKC. We found, in agreement with recent reports, that enzastaurin inhibits cell proliferation and induces apoptosis. These results are consistent with decreased phosphorylation of the Akt pathway and its downstream targets. To provide new insights into the anti-tumor action of enzastaurin on non-Hodgkin lymphoma, we investigated its effects on gene expression profiles of the B cell lymphoma RL cell line by oligonucleotide microarray analysis. We identified a set of 41 differentially expressed genes, mainly involved in cellular adhesion, apoptosis, inflammation, and immune and defense responses. These observations provide new insights into the mechanisms involved in the induction of apoptosis by enzastaurin in B cell lymphoma cell lines, and identify possible pathways that may contribute to the induction of apoptosis. This series of microarray experiments contains the gene expression profiles of independent replicates of the B lymphoma RL cell line carrying t(14;18) before and after LY317615 treatment. 100 nanograms of total RNA were processed and fragmented. Biotin-labelled single-stranded DNA target was hybridized to the GeneChip® Gene 1.0 ST array following the Affymetrix manufacturer's instructions.