Expression of CD163 prevents apoptosis through the production of granulocyte colony-stimulating factor in meningioma

摘要

Background. CD163 is a 130-kDa transmembrane protein expressed in human monocytes and macropha-ges, and the aberrant expression of CD 163 in breast and colorectal cancer associated with patients' poor prognosis was reported. Here, we analyzed the expression of CD 163 in meningioma, a common intracranial tumor, and its molecular mechanism in association with meningioma progression. Methods. First, we performed immunohistochemical analysis using 50 human meningioma specimens. Next, we established CD163-overexpressing human meningioma cell lines and investigated its roles in tumor progression in vitro and in vivo. Results. Immunohistochemically, 26 of 50 human meningioma specimens (52.0%) were positive for CD163 in tumor cells, including benign grade I (48.5%) and grade II (71.4%) cases. Furthermore, CD163 expression was correlated with histological atypical parameters that directly predict the prognosis of meningioma. CD 163-overexpressing meningioma cells showed significant suppression of apoptosis and accelerated tumor growth in nude mice. In addition, unexpected splenomegaly affiliated with the xenograft predicted tumor-derived granulocyte colony-stimulating factor (G-CSF) production, which was confirmed by reverse-transcription polymer-ase chain reaction and enzyme-linked immunosorbent assay. Conclusions. To our knowledge, this is the first report that demonstrates CD 163 expression in meningioma not only by immunohistochemistry but also by reverse- transcription polymerase chain reaction, using primary culture cells, and provides the novel molecular function of CD 163 to prevent apoptosis through the production of G-CSF in meningioma.