Human sperm-associated antigen 4 as a potential biomarker of glioblastoma progression and prognosis.

Glioblastoma (GBM) is a highly lethal brain tumor, refractory to current therapies. Sperm-associated antigen 4 (SPAG4) is a novel cancer marker with unclear roles in GBM progression. This study aimed to explore the specific effects of SPAG4 on the pathogenesis of GBM. We first investigated the expression level and prognostic power of SPAG4 in patients with GBM using The Cancer Genome Atlas cohort, and then SPAG4 knockdown by RNA interference was performed to reveal the effects of SPAG4 on GBM cells. mRNA and protein expression levels were determined by real-time PCR and western blot. MTT assay was used to examine cell proliferation, and a wound healing assay was performed to detect cell migration. SPAG4 was significantly overexpressed in patients with GBM, and high expression of SPAG4 was associated with a poor prognosis. Silencing of SPAG4 significantly suppressed the proliferation and migration of GBM cells. Meanwhile, decreased expression and phosphorylation of MEK and ERK were identified after SPAG4 knockdown, suggesting that SPAG4 might regulate GBM progression by activating MEK/ERK signaling pathway. Our study revealed that SPAG4 was identified as a cancer biomarker for GBM and might be a promising target for clinical diagnosis and intervention of GBM.