Long non‑coding RNA CASC19 promotes glioma progression by modulating the miR‑454‑3p/RAB5A axis and is associated with unfavorable MRI features

Glioma is one of the most common malignancies of the nervous system. Long non‑coding RNAs (lncRNAs) are regulators involved in the progression of tumors. The present study aimed to determine the role of lncRNA cancer susceptibility 19 (CASC19) in glioma and its underlying molecular mechanism. Reverse transcription‑quantitative PCR was performed to detect CASC19 and microRNA (miR)‑454‑3p expression in glioma and normal brain tissues. Ras‑related protein in brain 5A (RAB5A) expression in glioma cells was also analyzed via western blotting. The relationship between CASC19 expression, clinicopathological parameters and MRI characteristics in patients with glioma was analyzed. Cell Counting Kit‑8, BrdU, wound healing and Transwell assays were adopted to detect glioma cell proliferation, migration and invasion, respectively. The dual‑luciferase reporter gene and RNA immunoprecipitation experiments were conducted to verify the targeting relationship between CASC19 and miR‑454‑3p, and between miR‑454‑3p and RAB5A. The results revealed that CASC19 expression was significantly upregulated in glioma tissues and cell lines. CASC19 expression was also positively associated with tumor diameter and pathological grade. Additionally, its high expression was closely associated with tumor MRI signal heterogeneity and peritumoral edema. CASC19 upregulation promoted glioma cell proliferation and metastasis, while CASC19‑knockdown demonstrated the opposite effect. CASC19 sponged miR‑454‑3p, which indirectly increased RAB5A expression. The results demonstrated that the CASC19/miR‑454‑3p/RAB5A axis is involved in the promotion of glioma progression.