Characteristics of the expression of KAI1/CD82 and PDGFRβ and their impact on glioma progression

The biological features of glioma cells may define their clinical outcome. Little is known about the interactions between KAI1/CD82 metastatic suppressor protein and PDGFR in gliomas. The aim of the study was to examine KAI1/CD82 and PDGFR expression in gliomas in order to find the impact of these proteins on progression of the tumors. PDGFR, KAI1/CD82 protein expression and mRNA of genes were evaluated on eighty four paraffin-embedded tissue of gliomas using immunohistochemical staining and RT-PCR analysis. The PDGFR expression was higher in IV/III than in I/II glioma grades (p = 0.0004). The level of mRNA PDGFR was associated with the degree of PDGFR immunoreactivity. Downregulation of KAI1/CD82 was associated with tumor malignancy (p = 0.007). The increased level of KAI1/CD82 gene expression (3-4-fold) was found in gliomas with strong KAI1/CD82 immunoreactivity. The parallel KAI1/CD82 and PDGFR expression was more significantly associated with cases in a group graded as III and IV than in a group graded as I/II (p = 0.002).

We found that a loss of KAI1/CD82 and an increase in PDGFR expression in gliomas relate to a progressive tumor growth. The correlation between PDGFR and KAI1 expression in high grade gliomas suggests that a direct or indirect interaction between these proteins might have an impact on cell motility and invasive behavior of the tumor.