Department of General Surgery, Qilu Hospital of Shandong University, Jinan 250012, China.
Aging (Albany NY). 2020 Jun 21;12(12):11685-11697. doi: 10.18632/aging.103334.
In this study, we investigated the mechanistic role and prognostic significance of the long coding RNA (lncRNA) KCNQ1OT1 in colorectal cancer (CRC). KCNQ1OT1 levels were significantly higher in CRC tissues than adjacent normal colorectal tissues (n=79). High KCNQ1OT1 expression correlated with poorer prognosis in CRC patients. KCNQ1OT1-silenced CRC cells showed reduced proliferation, colony formation, extracellular acidification, and lactate and glucose secretion. This suggests KCNQ1OT1 promotes CRC cell proliferation by increasing aerobic glycolysis. RNA pull-down assays with biotinylated KCNQ1OT1 followed by mass spectrometry analysis showed that KCNQ1OT1 directly binds to hexokinase 2 (HK2). This was confirmed by RNA immunoprecipitation assays using anti-hexokinase 2 antibody. HK2 protein levels were reduced in KCNQ1OT1 knockdown CRC cells, but were restored by treatment with the proteasomal inhibitor MG132. KCNQ1OT1 knockdown CRC cells also showed higher ubiquitinated-HK2 levels, suggesting KCNQ1OT1 enhances aerobic glycolysis by stabilizing HK2. HK2 overexpression in KCNQ1OT1 knockdown CRC cells restored proliferation and aerobic glycolysis. KCNQ1OT1 levels correlated positively with HK2 expression and prognosis in CRC patients. These findings show that KCNQ1OT1 promotes colorectal carcinogenesis by increasing aerobic glycolysis through HK2.
在这项研究中，我们研究了长编码 RNA (lncRNA) KCNQ1OT1 在结直肠癌 (CRC) 中的机制作用和预后意义。KCNQ1OT1 在 CRC 组织中的水平明显高于相邻的正常结直肠组织 (n=79)。KCNQ1OT1 高表达与 CRC 患者预后不良相关。沉默 KCNQ1OT1 的 CRC 细胞增殖、集落形成、细胞外酸化以及乳酸和葡萄糖分泌减少。这表明 KCNQ1OT1 通过增加有氧糖酵解促进 CRC 细胞增殖。用生物素标记的 KCNQ1OT1 进行 RNA 下拉测定，然后进行质谱分析，显示 KCNQ1OT1 直接与己糖激酶 2 (HK2) 结合。使用抗己糖激酶 2 抗体的 RNA 免疫沉淀测定证实了这一点。在 KCNQ1OT1 敲低的 CRC 细胞中，HK2 蛋白水平降低，但用蛋白酶体抑制剂 MG132 处理后恢复。KCNQ1OT1 敲低的 CRC 细胞中也显示出更高的泛素化-HK2 水平，表明 KCNQ1OT1 通过稳定 HK2 增强有氧糖酵解。在 KCNQ1OT1 敲低的 CRC 细胞中过表达 HK2 恢复了增殖和有氧糖酵解。KCNQ1OT1 水平与 HK2 表达和 CRC 患者的预后呈正相关。这些发现表明，KCNQ1OT1 通过增加 HK2 促进有氧糖酵解从而促进结直肠发生癌变。
