Exosome EpCAM promotes the metastasis of glioma by targeting the CD44 signaling molecule on the surface of glioma cells.

BACKGROUND:Glioma, the most common primary tumor in the central nervous system, originates from glial cells and has a poor prognosis. OBJECTIVES:This experimental laboratory study was designed to explore the role of epithelial cell adhesion molecule (EpCAM) in the metastasis of glioma. MATERIAL AND METHODS:Serum samples were collected from patients with non-metastatic or metastatic glioma (n = 20 per group), and healthy volunteers (n = 8). Exosomes were isolated from the serum and the morphological characteristics were observed under a scanning electron microscope (SEM). The expression of CD81 and CD63 was measured to identify exosomes. Glioma tissue and the adjacent normal tissue samples were obtained from patients with non-metastatic or metastatic glioma (n = 12 per group). Meanwhile, 4 normal brain tissue samples were collected. The expression of CD44, hyaluronan-mediated motility receptor (HMMR), and matrix metalloproteinase-9 (MMP-9) was determined in each group using immunohistochemistry. The protein expression of CD44, HMMR, matrix metalloproteinase-2 (MMP-2), MMP-9, and selectin E (SELE) was measured with western blotting. RESULTS:Exosomes were present in the serum, and the proteins CD81 and CD63 were expressed in all 3 groups. CD44 was highly expressed in the non-metastasis and metastasis groups. The expression of HMMR and MMP-9 in the Adj-metastasis and Adj-non-metastasis groups was high, while in the other groups, the levels were low. The expression of CD44 in the metastasis and non-metastasis groups was significantly higher than that of the negative control (NC) group, and the expression in the metastasis group was higher than that of the non-metastasis group. The MMP-2 and MMP-9 were not found in either the metastasis or non-metastasis group. The protein expression of HMMR and SELE was high in all groups. CONCLUSIONS:Exosome EpCAM promoted the metastasis of glioma by targeting CD44.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}