Department of Endocrinology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
Cancer Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
J Cell Mol Med. 2020 Nov;24(21):12642-12655. doi: 10.1111/jcmm.15832. Epub 2020 Sep 27.
PLA2G16 is a member of the phospholipase family that catalyses the generation of lysophosphatidic acids (LPAs) and free fatty acids (FFAs) from phosphatidic acid. In the current study, we explored the functional role of PLA2G16 in pancreatic adenocarcinoma (PAAD) and the genetic/epigenetic alterations leading to its dysregulation. Bioinformatic analysis was performed using data from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) and the Human Protein Atlas (HPA). Then, PANC-1 and MIA-PaCa-2 cells harbouring TP53 mutations were used for cellular and animal studies. Results showed that PL2G16 expression was significantly up-regulated in PAAD tissue and was associated with unfavourable survival. PLA2G16 inhibition suppressed pancreatic cell growth in vitro and in vivo and also inhibited aerobic glycolysis. Bioinformatic analysis indicated that KLF5 was positively correlated with PLA2G16 expression in PAAD tumours with TP53 mutation. TP53 or KLF5 inhibition significantly reduced PLA2G16 expression at both mRNA and protein levels. Dual-luciferase and chromatin Immunoprecipitation-quantitative polymerase chain reaction assays showed that KLF5 directly bound to the PLA2G16 promoter and activated its transcription. Co-immunoprecipitation assay indicated that mutant p53 had a physical interaction with KLF5. Inhibition of mutant p53 impaired the transcriptional activating effects of KLF5. In PAAD cases in TCGA, PLA2G16 expression was positively correlated with its copy number (Pearson's r = 0.51, P < 0.001), but was strongly and negatively correlated with the methylation level of cg09518969 (Pearson's r = -0.64, P < 0.001), a 5'-cytosine-phosphodiester bond-guanine-3' site within its gene locus. In conclusion, this study revealed a novel mutant p53/KLF5-PLA2G16 regulatory axis on tumour growth and glycolysis in PAAD.
PLA2G16 是磷脂酶家族的成员，可催化磷脂酸生成溶血磷脂酸 (LPA) 和游离脂肪酸 (FFA)。在本研究中，我们探讨了 PLA2G16 在胰腺导管腺癌 (PAAD) 中的功能作用及其调控失调的遗传/表观遗传改变。使用来自癌症基因组图谱 (TCGA)、组织表达基因型 (GTEx) 和人类蛋白质图谱 (HPA) 的数据进行了生物信息学分析。然后，使用携带 TP53 突变的 PANC-1 和 MIA-PaCa-2 细胞进行细胞和动物研究。结果表明，PL2G16 表达在 PAAD 组织中显著上调，并与不良预后相关。PLA2G16 抑制可抑制体外和体内胰腺细胞的生长，并抑制有氧糖酵解。生物信息学分析表明，TP53 突变的 PAAD 肿瘤中，KLF5 与 PLA2G16 的表达呈正相关。TP53 或 KLF5 抑制可显著降低 PLA2G16 在 mRNA 和蛋白水平上的表达。双荧光素酶和染色质免疫沉淀定量聚合酶链反应试验表明，KLF5 直接与 PLA2G16 启动子结合并激活其转录。共免疫沉淀试验表明，突变型 p53 与 KLF5 具有物理相互作用。在 TCGA 的 PAAD 病例中，PLA2G16 的表达与拷贝数呈正相关 (Pearson r = 0.51, P < 0.001)，但与基因座内 cg09518969 的甲基化水平呈强烈负相关 (Pearson r = -0.64, P < 0.001)。CG09518969 是基因内 5' - 胞嘧啶-磷酸二酯键-鸟嘌呤-3' 位点。总之，本研究揭示了一个新的突变型 p53/KLF5-PLA2G16 调节轴在 PAAD 中的肿瘤生长和糖酵解中的作用。
