Background

Aerobic glycolysis is a unique tumor cell phenotype considered as one of the hallmarks of cancer. Aerobic glycolysis can accelerate tumor development by increasing glucose uptake and lactate production. In the present study, lactate dehydrogenase A (LDHA) is significantly increased within glioma tissue samples and cells, further confirming the oncogenic role of LDHA within glioma.

Methods

Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were applied for histopathological examination. The protein levels of LDHA, transporter isoform 1 (GLUT1), hexokinase 2 (HK2), phosphofructokinase (PFK) in target cells were detected by Immunoblotting. The predicted miR-9 binding to lncRNA Annexin A2 Pseudogene 2 (ANXA2P2) or the 3′ untranslated region (UTR) of LDHA was verified using Luciferase reporter assay. Cell viability or apoptosis were examined by MTT assay or Flow cytometry. Intracellular glucose and Lactate levels were measured using glucose assay kit and lactate colorimetric assay kit.

Results

The expression of ANXA2P2 showed to be dramatically upregulated within glioma tissue samples and cells. Knocking down ANXA2P2 within glioma cells significantly inhibited cell proliferation and aerobic glycolysis, as manifested as decreased lactate and increased glucose in culture medium, and downregulated protein levels of glycolysis markers, GLUT1, HK2, PFK, as well as LDHA. miR-9 was predicted to target both lncRNA ANXA2P2 and LDHA. The overexpression of miR-9 suppressed the cell proliferation and aerobic glycolysis of glioma cells. Notably, miR-9 could directly bind to LDHA 3′UTR to inhibit LDHA expression and decrease the protein levels of LDHA. ANXA2P2 competitively targeted miR-9, therefore counteracting miR-9-mediated repression on LDHA. Within tissues, miR-9 exhibited a negative correlation with ANXA2P2 and LDHA, respectively, whereas ANXA2P2 and LDHA exhibited a positive correlation with each other.

Conclusions

In conclusion, ANXA2P2/miR-9/LDHA axis modulates the aerobic glycolysis progression in glioma cells, therefore affecting glioma cell proliferation.

中文翻译：

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ANXA2P2/miR-9/LDHA 轴调节 Warburg 效应并影响胶质母细胞瘤的增殖和凋亡。

背景

有氧糖酵解是一种独特的肿瘤细胞表型，被认为是癌症的标志之一。有氧糖酵解可以通过增加葡萄糖摄取和乳酸产生来加速肿瘤的发展。在本研究中，乳酸脱氢酶 A (LDHA) 在胶质瘤组织样本和细胞中显着增加，进一步证实了 LDHA 在胶质瘤中的致癌作用。

方法

苏木精和伊红 (H&E) 和免疫组织化学 (IHC) 染色用于组织病理学检查。通过免疫印迹检测靶细胞中LDHA、转运蛋白同种型1（GLUT1）、己糖激酶2（HK2）、磷酸果糖激酶（PFK）的蛋白质水平。使用荧光素酶报告基因测定验证了预测的 miR-9 与 lncRNA Annexin A2 Pseudogene 2 (ANXA2P2) 或 LDHA 的 3' 非翻译区 (UTR) 的结合。通过MTT测定或流式细胞术检查细胞活力或细胞凋亡。使用葡萄糖测定试剂盒和乳酸比色测定试剂盒测量细胞内葡萄糖和乳酸水平。

结果

ANXA2P2 的表达在神经胶质瘤组织样本和细胞中显着上调。敲低神经胶质瘤细胞内的 ANXA2P2 可显着抑制细胞增殖和有氧糖酵解，表现为培养基中乳酸减少和葡萄糖增加，以及糖酵解标志物 GLUT1、HK2、PFK 和 LDHA 的蛋白质水平下调。预测 miR-9 同时靶向 lncRNA ANXA2P2 和 LDHA。miR-9的过表达抑制了胶质瘤细胞的细胞增殖和有氧糖酵解。值得注意的是，miR-9 可以直接结合 LDHA 3'UTR 以抑制 LDHA 表达并降低 LDHA 的蛋白质水平。ANXA2P2 竞争性靶向 miR-9，因此抵消了 miR-9 介导的对 LDHA 的抑制。在组织内，miR-9 分别与 ANXA2P2 和 LDHA 呈负相关，

结论

总之，ANXA2P2/miR-9/LDHA轴调节胶质瘤细胞中的有氧糖酵解进程，从而影响胶质瘤细胞增殖。