Sun Hong, Zhu Anyou, Zhang Lunjun, Zhang Jie, Zhong Zhengrong, Wang Fengchao
Department of Clinical Laboratory Science, the First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China.
Department of Pathology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai 200030, China.
Int J Mol Sci. 2015 Oct 15;16(10):24574-87. doi: 10.3390/ijms161024574.
Accumulating evidence shows that activity of the pyruvate kinase M2 (PKM2) isoform is closely related to tumorigenesis. In this study, we investigated the relationship between PKM2 expression, tumor invasion, and the prognosis of patients with lung adenocarcinoma. We retrospectively analyzed 65 cases of patients with lung adenocarcinoma who were divided into low and a high expression groups based on PKM2 immunohistochemical staining. High PKM2 expression was significantly associated with reduced patient survival. We used small interfering RNA (siRNA) technology to investigate the effect of targeted PKM2-knockout on tumor growth at the cellular level. In vitro, siRNA-mediated PKM2-knockdown significantly inhibited the proliferation, glucose uptake (25%), ATP generation (20%) and fatty acid synthesis of A549 cells, while the mitochondrial respiratory capacity of the cells increased (13%).Western blotting analysis showed that PKM2-knockout significantly inhibited the expression of the glucose transporter GLUT1 and ATP citrate lyase, which is critical for fatty acid synthesis. Further Western blotting analysis showed that PKM2-knockdown inhibited the expression of matrix metalloproteinase 2 (MMP-2) and vascular endothelial growth factor (VEGF), which are important in degradation of the extracellular matrix and angiogenesis, respectively. These observations show that PKM2 activates both glycolysis and lipid synthesis, thereby regulating cell proliferation and invasion. This information is important in elucidating the mechanisms by which PKM2 influences the growth and metastasis of lung adenocarcinoma at the cellular and molecular level, thereby providing the basic data required for the development of PKM2-targeted gene therapy.
越来越多的证据表明，丙酮酸激酶M2（PKM2）亚型的活性与肿瘤发生密切相关。在本研究中，我们调查了PKM2表达、肿瘤侵袭与肺腺癌患者预后之间的关系。我们回顾性分析了65例肺腺癌患者，根据PKM2免疫组化染色将其分为低表达组和高表达组。PKM2高表达与患者生存率降低显著相关。我们使用小干扰RNA（siRNA）技术在细胞水平上研究靶向敲除PKM2对肿瘤生长的影响。在体外，siRNA介导的PKM2敲低显著抑制了A549细胞的增殖、葡萄糖摄取（25%）、ATP生成（20%）和脂肪酸合成，而细胞的线粒体呼吸能力增加（13%）。蛋白质印迹分析表明，敲除PKM2显著抑制了对脂肪酸合成至关重要的葡萄糖转运蛋白GLUT1和ATP柠檬酸裂解酶的表达。进一步的蛋白质印迹分析表明，敲低PKM2抑制了基质金属蛋白酶2（MMP - 2）和血管内皮生长因子（VEGF）的表达，它们分别在细胞外基质降解和血管生成中起重要作用。这些观察结果表明，PKM2激活糖酵解和脂质合成，从而调节细胞增殖和侵袭。这些信息对于阐明PKM2在细胞和分子水平上影响肺腺癌生长和转移的机制非常重要，从而为开发靶向PKM2的基因治疗提供所需的基础数据。
