SRSF1 induces glioma progression and has a potential diagnostic application in grading primary glioma

Glioma is the most common intracranial tumor of the central nervous system in adults; however, the diagnosis of glioma, and its grading and histological subtyping, is challenging for pathologists. The present study assessed serine and arginine rich splicing factor 1 (SRSF1) expression in 224 glioma cases in the Chinese Glioma Genome Atlas (CGGA) database, and verified its expression by immunohistochemical analysis of specimens from 70 clinical patients. In addition, the prognostic potential of SRSF1 concerning the survival status of patients was evaluated. In vitro, the biological role of SRSF1 was assessed using MTT, colony formation, wound healing and Transwell assays. The results revealed that SRSF1 expression was significantly associated with the grading and the histopathological subtype of glioma. As determined using a receiver operating characteristic curve analysis, the specificity of SRSF1 for glioblastoma (GBM) and World Health Organization (WHO) grade 3 astrocytoma was 40 and 48%, respectively, whereas the sensitivity was 100 and 85%. By contrast, pilocytic astrocytoma tumors exhibited negative immunoexpression of SRSF1. Additionally, Kaplan-Meier survival analysis indicated that high SRSF1 expression predicted a worse prognosis for patients with glioma in both the CGGA and clinical cohorts. In vitro, the results demonstrated that SRSF1 promoted the proliferation, invasion and migration of U87MG and U251 cells. These data suggested that immunohistochemical analysis of SRSF1 expression is highly sensitive and specific in the diagnosis of GBM and WHO grade 3 astrocytoma, and may have an important role in glioma grading. Furthermore, the lack of SRSF1 is a potential diagnostic biomarker for pilocytic astrocytoma. However, neither in oligodendroglioma and astrocytoma, nor in GBM was an association detected between SRSF1 expression and IDH1 mutations or 1p/19q co-deletion. These findings indicated that SRSF1 may serve as a prognostic factor in glioma cases and could have an active role in promoting glioma progression.