Liu Wenting, Jiang Kaiting, Wang Jingya, Mei Ting, Zhao Min, Huang Dingzhi
Department of Thoracic Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, China.
Front Mol Biosci. 2021 Mar 25;8:605754. doi: 10.3389/fmolb.2021.605754. eCollection 2021.
Glucosamine 6-phosphate -acetyltransferase (GNPNAT1) is a key enzyme in the hexosamine biosynthetic pathway (HBP), which functions as promoting proliferation in some tumors, yet its potential biological function and mechanism in lung adenocarcinoma (LUAD) have not been explored.
The mRNA differential expression of GNPNAT1 in LUAD and normal tissues was analyzed using the Cancer Genome Atlas (TCGA) database and validated by real-time PCR. The clinical value of GNPNAT1 in LUAD was investigated based on the data from the TCGA database. Then, immunohistochemistry (IHC) of GNPNAT1 was applied to verify the expression and clinical significance in LUAD from the protein level. The relationship between GNPNAT1 and epigenetics was explored using the cBioPortal database, and the miRNAs regulating GNPNAT1 were found using the miRNA database. The association between GNPNAT1 expression and tumor-infiltrating immune cells in LUAD was observed through the Tumor IMmune Estimation Resource (TIMER). Finally, Gene set enrichment analysis (GSEA) was used to explore the biological signaling pathways involved in GNPNAT1 in LUAD.
GNPNAT1 was upregulated in LUAD compared with normal tissues, which was verified through qRT-PCR in different cell lines ( < 0.05), and associated with patients' clinical stage, tumor size, and lymphatic metastasis status (all < 0.01). Kaplan-Meier (KM) analysis suggested that patients with upregulated GNPNAT1 had a relatively poor prognosis ( < 0.0001). Furthermore, multivariate Cox regression analysis indicated that GNPNAT1 was an independent prognostic factor for LUAD (OS, TCGA dataset: HR = 1.028, 95% : 1.013-1.044, < 0.001; OS, validation set: HR = 1.313, 95% : 1.130-1.526, < 0.001). GNPNAT1 overexpression was correlated with DNA copy amplification ( < 0.0001), low DNA methylation ( = -0.52, < 0.0001), and downregulation of hsa-miR-30d-3p ( = -0.17, < 0.001). GNPNAT1 expression was linked to B cells ( = -0.304, < 0.0001), CD4T cells ( = -0.218, < 0.0001), and dendritic cells ( = -0.137, = 0.002). Eventually, GSEA showed that the signaling pathways of the cell cycle, ubiquitin-mediated proteolysis, mismatch repair and p53 were enriched in the GNPNAT1 overexpression group.
GNPNAT1 may be a potential prognostic biomarker and novel target for intervention in LUAD.
6-磷酸葡萄糖胺-N-乙酰转移酶（GNPNAT1）是己糖胺生物合成途径（HBP）中的关键酶，在某些肿瘤中具有促进增殖的作用，但其在肺腺癌（LUAD）中的潜在生物学功能及机制尚未得到探索。
利用癌症基因组图谱（TCGA）数据库分析LUAD组织和正常组织中GNPNAT1的mRNA差异表达，并通过实时PCR进行验证。基于TCGA数据库的数据研究GNPNAT1在LUAD中的临床价值。然后，应用GNPNAT1的免疫组织化学（IHC）从蛋白质水平验证其在LUAD中的表达及临床意义。利用cBioPortal数据库探索GNPNAT1与表观遗传学的关系，并通过miRNA数据库寻找调控GNPNAT1的miRNA。通过肿瘤免疫估计资源（TIMER）观察GNPNAT1表达与LUAD中肿瘤浸润免疫细胞的关联。最后，采用基因集富集分析（GSEA）探索LUAD中与GNPNAT1相关的生物信号通路。
与正常组织相比，GNPNAT1在LUAD中上调，这在不同细胞系中通过qRT-PCR得到验证（<0.05），且与患者的临床分期、肿瘤大小和淋巴转移状态相关（均<0.01）。Kaplan-Meier（KM）分析表明，GNPNAT1上调的患者预后相对较差（<0.0001）。此外，多因素Cox回归分析表明，GNPNAT1是LUAD的独立预后因素（总生存期，TCGA数据集：HR = 1.028，95%：1.013 - 1.044，<0.001；总生存期，验证集：HR = 1.313，95%：1.130 - 1.526，<0.001）。GNPNAT1过表达与DNA拷贝数扩增相关（<0.0001）、低DNA甲基化（=-0.52，<0.0001）以及hsa-miR-30d-3p下调（=-0.17，<0.001）。GNPNAT1表达与B细胞（=-0.304，<0.0001）、CD4 T细胞（=-0.218，<0.0001）和树突状细胞（=-0.137，=0.002）有关。最终，GSEA显示细胞周期、泛素介导的蛋白水解、错配修复和p53信号通路在GNPNAT1过表达组中富集。
GNPNAT1可能是LUAD潜在的预后生物标志物和新的干预靶点。
