Osteopontin Expression Correlates with Angiogenesis and Survival in Malignant Astrocytoma

Abstract

Osteopontin (OPN) is a phosphorylated glycoprotein with diverse functions including angiogenesis, cancer development, invasion and metastasis. The aim of the study was to analyze the expression of OPN in human astrocytomas and to correlate it with angiogenesis and patients' outcome. Seventy-six human astrocytomas including eight pilocytic astrocytomas (grade I), 10 diffuse astrocytomas (grade II), 8 anaplastic astrocytomas (grade III) and 50 glioblastomas (grade IV) were immunohistochemically stained for OPN protein. The distribution of OPN staining (cytoplasmic and/or interstitial) was assessed and compared to microvessel number and patients' survival. In normal brain tissue some glial and neuronal cells showed weak cytoplasmic staining, while interstitium was negative. Astrocytomas were heterogeneous regarding the OPN expression. High cytoplasmic OPN expression in glioblastomas was associated with poor patients' survival (p = 0.012). Also, we found the association of interstitial OPN expression and angiogenesis (p = 0.033), i.e. the number of newly formed blood vessels was higher in tumors showing high interstitial OPN expression. Our results indicate the overexpression of OPN protein in astrocytoma cells and suggest the role of OPN in astrocytoma progression and angiogenesis.

Anti-inflammatory effects of thymoquinone in activated BV-2 microglial cells

“…In resting BV-2 cells, osteopontin was the highest protein expressed, which could be a function of immortality as it is consistently reported in aggressive malignant glioblastomas (Jang et al, 2006, Matusan-Ilijas et al, 2008), in cerebrospinal fluid samples from glioma cancer patients (Yamaguchi et al, 2013) and its concentration is associated with invasiveness potential (Jan et al, 2010). Although very little is known about a role of osteopontin in primary microglia cells, it has been suggested to be a contributing factor to protection of nigral dopaminergic neurons somehow involving integrin and CD44 receptor interactions that promote neuronal remodeling (Hasegawa-Ishii et al, 2011, Liao et al, 2011) and survival (Del Rio et al, 2011).…”

The association of osteopontin and LMX1A expression with World Health Organization grade in meningiomas and gliomas

“…The WHO grading system for gliomas depends on nuclear atypism, mitotic activity, and the presence of necrosis and microvascular hyperplasia 40–43 . Of all the malignant primary brain tumours, astrocytoma is the most common type, and derives from glial cells 44 . Various genetic alterations, such as TP53 and PTEN mutations, epidermal growth factor receptor gene amplification, deletion of p16 , and loss of chromosome 10, may play a role in the tumorigenesis of astrocytomas 45,46 .…”

Identification of Potential Serum Biomarkers of Glioblastoma: Serum Osteopontin Levels Correlate with Poor Prognosis

“…OPN expression has been found to correlate with tumor progression in astrocytoma with high levels in GBM (33)(34)(35). OPN levels detected by immunohistochemistry identified that high cytoplasmic OPN expression correlates with poor patient survival (36). Although serum OPN levels have been shown to correlate with patient survival in other cancers (37), there has been no such report with respect to glioma.…”