UAP1L1 plays an oncogene-like role in glioma through promoting proliferation and inhibiting apoptosis

Uridine diphosphate-N-acetylglucosamine pyrophosphorylase-1-like-1 (UAP1L1) is involved in protein glycosylation and promotes proliferation in some tumors. By analyzing the publicly available Gene Expression Omnibus (GEO) database, we found that UAP1L1 displayed a significant change between paired glioma and normal brain tissues. The purpose of this study was to investigate the expression and functional role of UAP1L1 in glioma.

To determine the expression level of UAP1L1 in glioma, immunohistochemistry (IHC) staining was performed in tissue microarrays of 160 gliomas and 24 normal brain tissues. The correlation between UAP1L1 expression and the outcomes of glioma patients was analyzed. Human glioblastoma cell lines, U251 and U87, were employed in this study. Endogenous UAP1L1 expression in U251 and U87 cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). A lentiviral short hairpin RNA (shRNA) vector (shUAP1L1) was constructed and used to infect U251 and U87 cells to knock down the expression of UAP1L1. We performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, flow cytometry, human apoptosis antibody array, and in vivo subcutaneous xenograft model to investigate the biological functions of UAP1L1.

We revealed that UAP1L1 expression was obviously upregulated in the glioma tissues. The increased UAP1L1 expression level was clinically associated with higher tumor grades and poorer patient prognoses. Moreover, we demonstrated that UAP1L1 knockdown suppressed proliferation and increased apoptosis of glioma cells in vitro. In the xenograft mouse model, we further verified that UAP1L1 knockdown could attenuate the growth of glioma cells in vivo.

These results indicated that UAP1L1 may play an oncogene-like role in glioma, especially in high grade glioma, and thus may be of clinical importance as a future therapeutic target.