腫瘤突變形成促進腫瘤進展微環境
作者:
小柯機器人發布時間:2020/7/9 9:59:43
日本國立癌症中心研究所/腫瘤探索研究與臨床試驗中心(EPOC)Hiroyoshi Nishikawa和Yosuke Togashi研究組取得最新進展。他們發現致癌性改變通過賦予調節性T(Treg)細胞代謝優勢,創造了促進腫瘤進展的微環境。這一研究成果發表在2020年7月7日出版的《免疫》上。
為了研究耐藥性的潛在機制,研究人員檢查了胃癌(GC)的免疫情況。這些腫瘤的一個亞群以高頻率的Treg細胞和少量的效應T細胞為特徵。基因組分析表明,這些腫瘤的RHOA突變,已知具有驅動腫瘤進展的作用。癌細胞中的RHOA突變激活了PI3K-AKT-mTOR信號傳導途徑,增加了游離脂肪酸的產生,與效應T細胞相比,Treg細胞更有效地消耗了游離脂肪酸。
RHOA突變型腫瘤對PD-1封閉有抵抗力,但對PD-1封閉與PI3K途徑抑制劑或靶向Treg細胞的療法的聯合治療有反應。研究人員認為,由RHOA突變賦予的代謝優勢使Treg細胞在GC腫瘤內積累,從而產生對免疫檢查點封鎖(ICB)產生抗性的免疫抑制性腫瘤微環境。
附:英文原文
Title: An Oncogenic Alteration Creates a Microenvironment that Promotes Tumor Progression by Conferring a Metabolic Advantage to Regulatory T Cells
Author: Shogo Kumagai, Yosuke Togashi, Chika Sakai, Akihito Kawazoe, Masahito Kawazu, Toshihide Ueno, Eiichi Sato, Takeshi Kuwata, Takahiro Kinoshita, Masami Yamamoto, Sachiyo Nomura, Tetsuya Tsukamoto, Hiroyuki Mano, Kohei Shitara, Hiroyoshi Nishikawa
Issue&Volume: 2020-07-07
Abstract: Only a small percentage of patients afflicted with gastric cancer (GC) respond toimmune checkpoint blockade (ICB). To study the mechanisms underlying this resistance,we examined the immune landscape of GC. A subset of these tumors was characterizedby high frequencies of regulatory T (Treg) cells and low numbers of effector T cells.Genomic analyses revealed that these tumors bore mutations in RHOA that are known to drive tumor progression. RHOA mutations in cancer cells activated the PI3K-AKT-mTOR signaling pathway, increasingproduction of free fatty acids that are more effectively consumed by Treg cells thaneffector T cells. RHOA mutant tumors were resistant to PD-1 blockade but responded to combination of PD-1blockade with inhibitors of the PI3K pathway or therapies targeting Treg cells. Wepropose that the metabolic advantage conferred by RHOA mutations enables Treg cell accumulation within GC tumors, generating an immunosuppressiveTME that underlies resistance to ICB.
DOI: 10.1016/j.immuni.2020.06.016
Source: https://www.cell.com/immunity/fulltext/S1074-7613(20)30271-5