Zheng Yongjia, Liang Minting, Wang Bowen, Kang Li, Yuan Yanqiu, Mao Yang, Wang Shengjun
School of Pharmaceutical Sciences, National-Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, 510006, China.
College of Life Science, Northwest University, Xi'an, 710127, China.
Biochem Biophys Res Commun. 2022 Jun 25;610:99-106. doi: 10.1016/j.bbrc.2022.04.052. Epub 2022 Apr 14.
Abnormal expression of mucin-type O-glycosylation has been reported to be associated with a variety of human cancers including gliomas. However, little is known about its contribution to the malignancy of Glioblastoma Multiforme (GBM), the deadliest form of brain tumors. Here, we conducted a detailed analysis of the expression profiles of GALNT gene family, which encode polypeptide-N-acetyl-galactosaminyltransferases (GalNAc-Ts) and are responsible for initiating O-glycans, both in the Cancer Genome Atlas (TCGA) and in the Chinese Glioma Genome Atlas (CGGA) databases. We discovered that GALNT12 is the only member within the GALNT family, whose expression demonstrated significant correlation with a worse prognosis of GBM. Genetic knockdown (KD) and knockout (KO) of GALNT12 in U87 MG, a representative GBM cell line with high GALNT12 expression, confirmed that GALNT12 deficiency leads to decreased cell proliferation, migration and invasion. Mechanism study revealed that GALNT12 KD and KO decreased the level of epidermal growth factor (EGF) and consequently attenuated Akt signaling within the cell. In summary, our results indicated that GALNT12 facilitates the malignant characteristics of GBM by influencing the PI3K/Akt/mTOR axis and may serve as a novel prognosis biomarker and a potential therapeutic target of GBM.
据报道,粘蛋白型O-糖基化的异常表达与包括神经胶质瘤在内的多种人类癌症有关。然而,对于其在多形性胶质母细胞瘤(GBM)(最致命的脑肿瘤形式)恶性肿瘤中的作用知之甚少。在此,我们对GALNT基因家族的表达谱进行了详细分析,该家族编码多肽-N-乙酰半乳糖胺基转移酶(GalNAc-Ts)并负责启动O-聚糖,分析数据来自癌症基因组图谱(TCGA)和中国胶质瘤基因组图谱(CGGA)数据库。我们发现GALNT12是GALNT家族中唯一的成员,其表达与GBM的较差预后显著相关。在具有高GALNT12表达的代表性GBM细胞系U87 MG中对GALNT12进行基因敲低(KD)和敲除(KO),证实GALNT12缺陷导致细胞增殖、迁移和侵袭减少。机制研究表明,GALNT12的KD和KO降低了表皮生长因子(EGF)水平,从而减弱了细胞内的Akt信号传导。总之,我们的结果表明,GALNT12通过影响PI3K/Akt/mTOR轴促进GBM的恶性特征,可能作为GBM的一种新的预后生物标志物和潜在的治疗靶点。