Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1, Canada.
Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
Pharmacol Rep. 2020 Jun;72(3):631-640. doi: 10.1007/s43440-019-00045-6. Epub 2020 Feb 10.
The M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2) is one of the key components in the Warburg effect, and an important regulator of cancer cell metabolism. Elevated PKM2 expression is a hallmark of numerous tumor types, making it a promising target for cancer therapy.
Migration of H1299 lung tumor cells treated with synthetic oleanane triterpenoid derivatives CDDO-Me and CDDO-Im was monitored using scratch and transwell assays. Direct binding and inhibition of PKM2 activity by CDDO-Me was demonstrated by pull-down and activity assays. PKM2 localization in the absence and presence of CDDO-Me or CDDO-Im was determined by subcellular fractionation and immunofluorescence microscopy. Involvement of PKM2 in tumor cell migration was assessed using a stable PKM2 knockdown cell line.
We demonstrate that migration of H1299 lung tumor cells is inhibited by CDDO-Me and CDDO-Im in scratch and transwell assays. CDDO-Me binds directly and specifically to recombinant PKM2, leading to a reduction of its catalytic activity. PKM2 knockdown cells exhibit significantly lower migration compared to control cells when subjected to glucose and oxygen deprivation, but not under regular conditions.
The results suggest that PKM2 expression in a tumor-like environment contributes to cell migration, and that PKM2 activity can be down regulated by synthetic triterpenoid derivatives.
糖酵解酶丙酮酸激酶（PKM2）的 M2 同工酶是瓦博格效应的关键组成部分之一，也是癌细胞代谢的重要调节剂。高水平的 PKM2 表达是许多肿瘤类型的标志，使其成为癌症治疗的有前途的靶点。
使用划痕和 Transwell 测定法监测用合成齐墩果酸三萜衍生物 CDDO-Me 和 CDDO-Im 处理的 H1299 肺肿瘤细胞的迁移。通过下拉和活性测定证明 CDDO-Me 与 PKM2 的直接结合和抑制活性。通过亚细胞分级分离和免疫荧光显微镜确定 CDDO-Me 或 CDDO-Im 存在和不存在时的 PKM2 定位。使用稳定的 PKM2 敲低细胞系评估 PKM2 在肿瘤细胞迁移中的作用。
我们证明 CDDO-Me 和 CDDO-Im 在划痕和 Transwell 测定中抑制 H1299 肺肿瘤细胞的迁移。CDDO-Me 直接且特异性地与重组 PKM2 结合，导致其催化活性降低。与对照细胞相比，在葡萄糖和氧气剥夺下，PKM2 敲低细胞的迁移明显降低，但在常规条件下则没有。
结果表明，肿瘤样环境中的 PKM2 表达有助于细胞迁移，并且 PKM2 活性可以通过合成三萜衍生物下调。
