A microarray-based, integrated approach to identify novel regulators of cancer drug response and apoptosis.
DNA microarrays are powerful tools for the analysis of gene expression on a genomic scale. The importance of individual regulatory events for the process under study can however not be deduced unequivocally without additional experiments. We devised a strategy to identify central regulators of cancer drug responses by combining the results of microarray experiments with efficient methods for phenotypic testing of candidate genes. We exposed murine FL5.12 pro-B cells to cisplatin, camptothecin, methotrexate or paclitaxel, respectively and analysed the patterns of gene expression with cDNA microarrays. Drug-specific regulatory events as well as intersections between different apoptotic pathways, including previously studied responses to staurosporine and interleukin-3 (IL-3) deprivation, were identified. Genes shared by at least three pathways were chosen for further analysis. Ectopic expression of three such genes, TEAP, GP49B, and Lipin1 was found to have an anti-proliferative effect on pro-B cells. Interestingly, we identified hemoglobin alpha as a strong pro-apoptotic regulator. While hemoglobin-expressing cells were growing normally in the presence of IL-3, they displayed accelerated apoptosis with similar kinetics as Bax overexpressing cells upon IL-3 removal. The pro-apoptotic effect of hemoglobin was suppressed by Bcl-2 and was characterized by enhanced stimulation of caspase activity.
Brachat
Arndt
A
Oncology Research, Novartis Pharma AG, CH-4002 Basel, Switzerland.
Pierrat
Benoit
B
Xynos
Alexandros
A
Brecht
Karin
K
Simonen
Marjo
M
Brüngger
Adrian
A
Heim
Jutta
J
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D020224:Expressed Sequence Tags; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D007377:Interleukin-3 / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D019311:Staurosporine / Q000494:pharmacology
D000970:Antineoplastic Agents; D018076:DNA, Complementary; D007377:Interleukin-3; D019311:Staurosporine