钙通道 α2δ1 通过 PKM2 的顺序磷酸化对胰腺肿瘤起始细胞是必需的。

Calcium Channel α2δ1 is Essential for Pancreatic Tumor-Initiating Cells through Sequential Phosphorylation of PKM2.

机构信息

Key Laboratory of Carcinogenesis and Translational Research, (Ministry of Education/Beijing), Department of Cell Biology, Peking University Cancer Hospital and Institute, Beijing, P.R. China; Department of Pharmacology, Peking University Cancer Hospital and Institute, Beijing, P.R. China.

Department of General Surgery, Peking University Third Hospital, Beijing, P.R. China.

出版信息

Cell Mol Gastroenterol Hepatol. 2023;15(2):373-392. doi: 10.1016/j.jcmgh.2022.10.006. Epub 2022 Oct 14.

DOI:10.1016/j.jcmgh.2022.10.006

PMID:36244646

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9791133/

Abstract

BACKGROUND & AIMS: Tumor-initiating cells (TICs) drive pancreatic cancer tumorigenesis, therapeutic resistance, and metastasis. However, TICs are highly plastic and heterogenous, which impede the robust identification and targeted therapy of such a population. The aim of this study is to identify the surface marker and therapeutic target for pancreatic TICs.

METHODS

We isolated voltage-gated calcium channel α2δ1 subunit (isoform 5)-positive subpopulation from pancreatic cancer cell lines and freshly resected primary tissues by fluorescence-activated cell sorting and evaluated their TIC properties by spheroid formation and tumorigenic assays. Coimmunoprecipitation was used to identify the direct substrate of CaMKⅡδ.

RESULTS

We demonstrate that the voltage-gated calcium channel α2δ1 subunit (isoform 5) marks a subpopulation of pancreatic TICs with the highest TIC frequency among the known pancreatic TIC markers tested. Furthermore, α2δ1 is functionally sufficient and indispensable to promote TIC properties by mediating Ca influx, which activates CaMKⅡδ to directly phosphorylate PKM2 at T454 that results in subsequent phosphorylation at Y105 to translocate into nucleus, enhancing the stem-like properties. Interestingly, blocking α2δ1 with its specific antibody has remarkably therapeutic effects on pancreatic cancer xenografts by reducing TICs.

CONCLUSIONS

α2δ1 promotes pancreatic TIC properties through sequential phosphorylation of PKM2 mediated by CaMKⅡδ, and targeting α2δ1 provides a therapeutic strategy against TICs for pancreatic cancer.

摘要

背景与目的

肿瘤起始细胞（TICs）驱动胰腺癌的肿瘤发生、治疗耐药和转移。然而，TICs 具有高度可塑性和异质性，这阻碍了对该群体的稳健鉴定和靶向治疗。本研究旨在鉴定胰腺 TIC 的表面标志物和治疗靶点。

方法

我们通过荧光激活细胞分选从胰腺癌细胞系和新鲜切除的原发性组织中分离电压门控钙通道α2δ1 亚基（同种型 5）阳性亚群，并通过球体形成和致瘤性测定评估其 TIC 特性。共免疫沉淀用于鉴定 CaMKⅡδ 的直接底物。

结果

我们证明电压门控钙通道α2δ1 亚基（同种型 5）标记了具有最高 TIC 频率的胰腺 TIC 亚群，在测试的已知胰腺 TIC 标志物中。此外，α2δ1 具有功能上的充分性和不可或缺性，通过介导 Ca 内流来促进 TIC 特性，从而激活 CaMKⅡδ 直接将 PKM2 磷酸化在 T454 上，导致随后在 Y105 上磷酸化以转位到核内，增强干性特性。有趣的是，用其特异性抗体阻断 α2δ1 可显著减少胰腺癌细胞异种移植中的 TIC，从而产生治疗效果。