Methods: Affymetrix microarrays were conducted to study differentially (P<0.05) expressed genes in carcinoma cells after 6h and 24h of EMD or TGF-B1 incubations. Gene Ontology (GO) enrichment analyses from the regulated genes were also conducted.
Results: After 6h of EMD (200 microg/ml) or TGF-B1 (10 ng/ml) treatment, 48 and 393 genes, respectively, were regulated (P<0.05). 17 up- and five down-regulated genes were the same in the two study groups. After 24h incubations, only 12 genes by EMD but 346 genes by TGF-B1 were regulated, and two up- and two down-regulated genes were the same. The most up-regulated MMP after 6h incubation by EMD was MMP-10, and by TGF-B1 MMP-1, -9 and -10. After 24h incubation, MMP-9 was the most up-regulated gene in both study groups. However, MMP-10 was now the most down-regulated gene after EMD treatment, and not regulated in TGF-B1 treated cells. The expression of MMP-10 by EMD treated carcinoma cells was also verified in protein level. GO analyses revealed five of the 15 most up-regulated terms being the same for EMD and TGF-B1 after 6h of treatment.
Conclusion: Both EMD and TGF-B1 regulate MMP-genes and also other genes related to carcinogenesis. However, TGF-B1 regulates more and mostly different genes. This suggests that TGF-B1 can not be the predominant cytokine in EMD, but may be present in low concentrations.