Gene expression profiling of pancreatic cancer cell conditioned myoblasts.. Mus musculus

We verified whether conditioned media (CM) from pancreatic cancer cell lines (MIAPaCa2, CAPAN-1, PANC-1, BxPC3) alter glucose metabolism and gene expression profiles (microarray experiment with a platform of 5000 skeletal muscle cDNA) in mice myoblasts. Myoblasts were incubated with control or pancreatic cancer CM for 14 and 24 hours. Lactate significantly increased in CM compared with non-conditioned myoblasts. No variations in expression levels of the main genes involved in glycolysis were found in CM myoblasts. Propionyl coenzyme A carboxylase and isocitrate dehydrogenase 3 beta genes, which encode enzymes of the tricarboxylic acid cycle, were overexpressed, while IGFIIR and VAMP5 genes were underexpressed in CM myoblasts. PAFAH1B1 and BCL-2 genes (intracellular signal transduction) and the serine protease cathepsin G (proteolysis), were overexpressed in CM myoblasts. Tyrosine accumulation in CM myoblasts suggested that proteolysis overcomes protein synthesis. Sorcin, actin alpha, troponin T1, and filamin A were underexpressed in CM myoblasts. Our findings demonstrate that pancreatic cancer cell conditioned media enhanced lactate production and induced proteolysis, possibly by altering expression levels of a large number of genes, not only those involved in protein biosynthesis and degradation or glucose metabolism, but also those involved in the tricarboxylic acid cycle and in vesicle traffic. Keywords: Mice myoblasts, pancreatic cancer cell lines (MIAPaCa2, CAPAN-1, PANC-1, BxPC3), cDNA microarrays Overall design: Myoblasts were incubated with control (MBN) or CAPAN-1 pancreatic cancer conditioned media (MBC) for 0, 14 and 24 hours. RNAs purified from MBC at 14 and 24 hours were compared with RNA from MBN at 0 hour and at the corresponding stages. These samples were labeled and hybridized to muscle specific microarrays produced by our group (Human Array 2.0). Two replicates of each experiment were performed using different microarray slides, in which sample and reference RNAs, labeled either with Cy3 or Cy5 fluorochromes, were crossed in both combinations (dye-swapping procedure).