Department of Oncology, First affiliated hospital of Xi'an Jiaotong University, Xi'an, China.
Department of Hepatobiliary Surgery, First affiliated hospital of Xi'an Jiaotong University, Xi'an, China.
J Cell Mol Med. 2020 Aug;24(16):9397-9408. doi: 10.1111/jcmm.15596. Epub 2020 Jul 7.
Caveolin-1 (Cav-1) is the principal structural component of caveolae, and its dysregulation occurs in cancer. However, the role of Cav-1 in pancreatic cancer (PDAC) tumorigenesis and metabolism is largely unknown. In this study, we aimed to investigate the effect of pancreatic stellate cell (PSC) Cav-1 on PDAC metabolism and aggression. We found that Cav-1 is expressed at low levels in PDAC stroma and that the loss of stromal Cav-1 is associated with poor survival. In PSCs, knockdown of Cav-1 promoted the production of reactive oxygen species (ROS), while ROS production further reduced the expression of Cav-1. Positive feedback occurs in Cav-1-ROS signalling in PSCs, which promotes PDAC growth and induces stroma-tumour metabolic coupling in PDAC. In PSCs, positive feedback in Cav-1-ROS signalling induced a shift in energy metabolism to glycolysis, with up-regulated expression of glycolytic enzymes (hexokinase 2 (HK-2), 6-phosphofructokinase (PFKP) and pyruvate kinase isozyme type M2 (PKM2)) and transporter (Glut1) expression and down-regulated expression of oxidative phosphorylation (OXPHOS) enzymes (translocase of outer mitochondrial membrane 20 (TOMM20) and NAD(P)H dehydrogenase [quinone] 1 (NQO1)). These events resulted in high levels of glycolysis products such as lactate, which was secreted by up-regulated monocarboxylate transporter 4 (MCT4) in PSCs. Simultaneously, PDAC cells took up these glycolysis products (lactate) through up-regulated MCT1 to undergo OXPHOS, with down-regulated expression of glycolytic enzymes (HK-2, PFKP and PKM2) and up-regulated expression of OXPHOS enzymes (TOMM20 and NQO1). Interrupting the metabolic coupling between the stroma and tumour cells may be an effective method for tumour therapy.
窖蛋白-1(Cav-1)是小窝的主要结构成分,其失调发生在癌症中。然而,Cav-1 在胰腺癌(PDAC)肿瘤发生和代谢中的作用在很大程度上是未知的。在这项研究中,我们旨在研究胰腺星状细胞(PSC)Cav-1 对 PDAC 代谢和侵袭的影响。我们发现,Cav-1 在 PDAC 基质中低表达,基质 Cav-1 的丢失与不良预后相关。在 PSCs 中,Cav-1 的敲低促进了活性氧(ROS)的产生,而 ROS 的产生进一步降低了 Cav-1 的表达。Cav-1-ROS 信号在 PSCs 中存在正反馈,促进 PDAC 生长,并诱导 PDAC 中基质-肿瘤代谢偶联。在 PSCs 中,Cav-1-ROS 信号的正反馈导致能量代谢向糖酵解转变,糖酵解酶(己糖激酶 2(HK-2)、6-磷酸果糖激酶(PFKP)和丙酮酸激酶同工酶 M2(PKM2))和转运蛋白(Glut1)表达上调,氧化磷酸化(OXPHOS)酶(外膜线粒体 20 转位酶(TOMM20)和 NAD(P)H 脱氢酶[醌]1(NQO1))表达下调。这些事件导致高水平的糖酵解产物,如乳酸,由 PSCs 中上调的单羧酸转运蛋白 4(MCT4)分泌。同时,PDAC 细胞通过上调的 MCT1 摄取这些糖酵解产物(乳酸)进行 OXPHOS,糖酵解酶(HK-2、PFKP 和 PKM2)表达下调,OXPHOS 酶(TOMM20 和 NQO1)表达上调。阻断基质和肿瘤细胞之间的代谢偶联可能是肿瘤治疗的有效方法。