Differences in the Expression Patterns of TGFβ Isoforms and Associated Genes in Astrocytic Brain Tumors

SIMPLE SUMMARY: Numerous molecular changes are observed during tumor progression. Genes associated with TGFβ isoforms are involved in many cancers, including brain cancer. Using molecular techniques to evaluate 43 brain tumor sections from patients at different stages of astrocytic brain tumor, we assessed differences in the expression patterns of genes associated with TGFβ isoforms and quantified the mRNA of three TGFβ isoforms. Our study confirmed significant differences in the expression of genes associated with TGFβ isoforms as well as differences in isoform expression and the identification of 16 genes that differentiate between disease grades. Database analysis revealed interactions between the products of these genes, some of which are associated with tumorigenesis. Differences in the expression patterns of transcripts associated with TGFβ isoforms confirm that they are involved in astrocytic brain tumor transformation. Quantitative assessment of TGFβ2 mRNA may be a useful method in the future to facilitate the diagnosis of disease grade. ABSTRACT: Genes associated with the TGFβ isoforms are involved in a number of different cancers, and their effect on the progression of brain tumors is also being discussed. Using an oligonucleotide microarray method, we assessed differences in expression patterns of genes in astrocytic brain tumor sections from 43 patients at different stages of disease. Quantitative mRNA assessment of the three TGFβ isoforms was also performed by real-time RT-qPCR. Oligonucleotide microarray data were analyzed using the PL-Grid Infrastructure. The microarray analysis showed a statistically significant (p < 0.05) increase in TGFβ1 and TGFβ2 expression in G3/G4 stage relative to G2, whereas real-time RT-qPCR validation confirmed this change only for the TGFβ2 isoform (p < 0.05). The oligonucleotide microarray method allowed the identification of 16 differential genes associated with TGFβ isoforms. Analysis of the STRING database showed that the proteins encoded by the analyzed genes form a strong interaction network (p < 0.001), and a significant number of proteins are involved in carcinogenesis. Differences in expression patterns of transcripts associated with TGFβ isoforms confirm that they play a role in astrocytic brain tumor transformation. Quantitative assessment of TGFβ2 mRNA may be a valuable method to complement the diagnostic process in the future.