CD74 as a Potential Prognostic Marker in Glioblastoma

CD74 is a cell membrane receptor for macrophage migration inhibitory factor (MIF) that is believed to play a role in tumor progression and metastasis. Astrocytoma is the most common type of brain cancers, which are classified by the World Health Organization (WHO) into four grades according to the degree of malignancy. In this study, we investigated MIF and CD74 gene expression levels in a large cohort of publicly available RNA sequencing data and evaluated the correlation between their protein expression with clinicopathological features as well as prognosis in an independent cohort of astrocytoma samples. Seventy-three patients with different grades of astrocytoma (WHO grade II diffuse astrocytoma, grade III anaplastic astrocytoma, and grade IV glioblastoma) were used for protein expression in this study. The expression of CD74 was assayed by immunohistochemistry and was significantly higher in high-grade glioblastoma than grade II and grade III astrocytoma (P < 0.004). Upregulated CD74 expression was frequently found in older patients (≥ 62 years). The expression of CD74 is correlated with overall survival (P = 0.05). Multivariate analysis shows that the CD74 expression is associated with poor prognosis in the presence of MIF expression (P = 0.039) and that CD74 is not an independent prognostic marker in glioblastoma. However, similar studies on larger sample size are required to make a definite conclusion on the role of CD74 in prognosis in glioblastoma.