Tac2-N Promotes Glioma Proliferation and Indicates Poor Clinical Outcomes

As the most common tumor of central nervous system in adults, glioma is characterized with poor prognosis. Tac2-N (TC2N) is a newly discovered protein that play potential roles in lung cancer and breast cancer progression. Here we aimed to investigate the expression, clinical significance, and function of TC2N in glioma. The mRNA level of TC2N in glioma patients was extracted from TCGA datasets. Immunohistochemistry staining was conducted to test protein expression of TC2N in glioma tissues. Chi-square test was used to assess correlations between TC2N expression and patients' clinicopathological characteristics. Kaplan-Meier method was used to plot survival curves. The prognostic predictive role of TC2N was evaluated by univariate and multivariate analyses. Knockdown assays were performed in U87 and U251 cell lines, respectively. Cell proliferation, colony formation, and subcutaneous mice xenografts were used to reveal the tumor-related role of TC2N in glioma. Compared with normal brain tissues, the mRNA level of TC2N was significantly higher in glioma tissues, whose dysregulated higher mRNA level was correlated with poorer overall survival. Similarly, higher protein expression of TC2N was observed in cases with larger tumor size and advanced WHO grades. Univariate and multivariate analyses identified TC2N as a novel independent prognostic factor of gliomas. In vitro and in vivo data demonstrated that TC2N interference can remarkably prevent glioma cell proliferation and tumor growth. In conclusion, high TC2N expression is significantly correlated with poor overall survival of glioma patients via enhancing tumor growth.