Su Yi, Yu Qiu-Hong, Wang Xiang-Yun, Yu Li-Ping, Wang Zong-Feng, Cao Ying-Chun, Li Jian-Dong
Department of E.N.T., Dongying People's Hospital, Shandong, 257091, China.
Department of E.N.T., Kenli People's Hospital, Shandong, China.
BMC Cancer. 2017 Jul 11;17(1):477. doi: 10.1186/s12885-017-3473-4.
Jumonji C domain 2A (JMJD2A), as a histone demethylases, plays a vital role in tumorigenesis and progression. But, its functions and underlying mechanisms of JMJD2A in nasopharyngeal carcinoma (NPC) metabolism are remained to be clarified. In this study, we investigated glycolysis regulation by JMJD2A in NPC and the possible mechanism.
JMJD2A expression was detected by Western blotting and Reverse transcription quantitative real-time PCR analysis. Then, we knocked down and ectopically expressed JMJD2A to detect changes in glycolytic enzymes. We also evaluated the impacts of JMJD2A-lactate dehydrogenase A (LDHA) signaling on NPC cell proliferation, migration and invasion. ChIP assays were used to test whether JMJD2A bound to the LDHA promoter. Finally, IHC was used to verify JMJD2A and LDHA expression in NPC tissue samples and analyze their correlation between expression and clinical features.
JMJD2A was expressed at high levels in NPC tumor tissues and cell lines. Both JMJD2A and LDHA expression were positively correlated with the tumor stage, metastasis and clinical stage. Additionally, the level of JMJD2A was positively correlated with LDHA expression in NPC patients, and higher JMJD2A and LDHA expression predicted a worse prognosis. JMJD2A alteration did not influence most of glycolytic enzymes expression, with the exception of PFK-L, PGAM-1, LDHB and LDHA, and LDHA exhibited the greatest decrease in expression. JMJD2A silencing decreased LDHA expression and the intracellular ATP level and increased LDH activity, lactate production and glucose utilization, while JMJD2A overexpression produced the opposite results. Furthermore, JMJD2A could combine to LDHA promoter region and regulate LDHA expression at the level of transcription. Activated JMJD2A-LDHA signaling pathway promoted NPC cell proliferation, migration and invasion.
JMJD2A regulated aerobic glycolysis by regulating LDHA expression. Therefore, the novel JMJD2A-LDHA signaling pathway could contribute to the Warburg effects in NPC progression.
Jumonji C结构域2A(JMJD2A)作为一种组蛋白去甲基化酶,在肿瘤发生和进展中起着至关重要的作用。但是,JMJD2A在鼻咽癌(NPC)代谢中的功能及其潜在机制仍有待阐明。在本研究中,我们研究了JMJD2A对NPC糖酵解的调控及其可能的机制。
通过蛋白质免疫印迹法和逆转录定量实时PCR分析检测JMJD2A的表达。然后,我们敲低并异位表达JMJD2A以检测糖酵解酶的变化。我们还评估了JMJD2A-乳酸脱氢酶A(LDHA)信号对NPC细胞增殖、迁移和侵袭的影响。染色质免疫沉淀试验用于检测JMJD2A是否与LDHA启动子结合。最后,免疫组化用于验证NPC组织样本中JMJD2A和LDHA的表达,并分析它们的表达与临床特征之间的相关性。
JMJD2A在NPC肿瘤组织和细胞系中高表达。JMJD2A和LDHA的表达均与肿瘤分期、转移和临床分期呈正相关。此外,NPC患者中JMJD2A的水平与LDHA的表达呈正相关,较高的JMJD2A和LDHA表达预示着预后较差。除了磷酸果糖激酶-L(PFK-L)、磷酸甘油酸变位酶-1(PGAM-1)、乳酸脱氢酶B(LDHB)和LDHA外,JMJD2A的改变对大多数糖酵解酶的表达没有影响,并且LDHA的表达下降最为明显。JMJD2A沉默降低了LDHA表达和细胞内ATP水平,并增加了LDH活性、乳酸产生和葡萄糖利用,而JMJD2A过表达则产生相反的结果。此外,JMJD2A可以结合到LDHA启动子区域并在转录水平上调节LDHA表达。激活的JMJD2A-LDHA信号通路促进了NPC细胞的增殖、迁移和侵袭。
JMJD2A通过调节LDHA表达来调控有氧糖酵解。因此,新的JMJD2A-LDHA信号通路可能在NPC进展中促成瓦伯格效应。