Immunohistochemical expression of chemokine receptor CXCR3 and its ligand CXCL10 in low-grade astrocytomas and glioblastoma multiforme: A tissue microarray-based comparison

Glioblastoma multiforme (GBM) and diffuse astrocytoma (DA) are the most frequently encountered gliomas. Due to poor prognosis and limited success of the currently available treatment modalities there is a need to identify new therapeutic targets. Chemokines (CKs) regulate cellular functions like chemotaxis, angiogenesis, apoptosis, and cell cycle progression that play role in tumor growth. Objective: To study comparative immunoexpression of CXCR3 and CXCL10 in DA and GBM using a high-throughput tissue microarray (TMA). Materials and Methods: A TMA of 1.0 mm core diameter was made from formalin-fixed, paraffin-embedded donor blocks of 25 pilocytic astrocytomas (PA), 45 DA, and 75 GBM. Immunohistochemical staining for CXCR3 and CXCL10 was performed. Results: Out of 145, 129 cores were suitable for immunohistochemical evaluation after processing and immunohistochemistry. Strong CXCR3 immunoexpression was observed in 72.7% cases of GBM as compared to 31.8% cases of DA. 50.7% of GBM and 24.5% of DA showed strong immunoexpression of CXCL10. Overall comparisons between DA and GBM for CXCR3 and CXCL10 showed statistically significant correlation between the two with P 0.001 and P = 0.02, respectively. A positive correlation was observed between CXCR3 and MIB-1. Pearson's correlation coefficient r = 0.548 and 0.330 for DA and GBM, respectively with P 0.01. Conclusion: GBM shows overexpression of CXCR3 and CXCL10 in comparison to DA, indicating that they play an important role in tumor growth and progression. Inhibition of this receptor-ligand axis may be a potential therapeutic target for arresting tumor growth and development of a glioblastoma.