Folr2,即叶酸受体2,是一种重要的基因,编码叶酸受体β(FRβ),参与叶酸的摄取和转运。叶酸是一种重要的维生素,对于细胞的生长和分裂至关重要。FRβ主要在肿瘤相关巨噬细胞(TAMs)中表达,与肿瘤的免疫微环境和肿瘤的发生发展密切相关。
在肝细胞癌(HCC)中,肿瘤微环境发生了显著的胎儿样重编程,包括胎儿相关内皮细胞(PLVAP/VEGFR2)和胎儿样(FOLR2)肿瘤相关巨噬细胞的重新出现。VEGF和NOTCH信号通路在维持这种肿瘤微环境中起着重要作用[1]。在非小细胞肺癌(NSCLC)细胞系中,FOLR2基因的表达上调,沉默FOLR2基因的表达可以抑制细胞增殖,增加细胞凋亡,并导致细胞周期停滞在G1期。FOLR2基因沉默还抑制了AKT、mTOR和S6K1的磷酸化,表明FOLR2基因在NSCLC中可能通过AKT/mTOR/S6K1信号通路发挥作用[4]。
在组织驻留巨噬细胞中,FOLR2是TLF+(TIMD4和/或LYVE1和/或FOLR2)巨噬细胞的标志基因,这些巨噬细胞通过自我更新维持,并且与单核细胞输入最少[3]。在肺组织中,FOLR2+间质巨噬细胞(IMs)是一个稳定的驻留群体,而FOLR2- IMs代表了一个驻留和招募IMs的混合群体[5]。在结直肠癌中,FOLR2+ LYVE1+巨噬细胞的存在与不良预后相关[8]。在肺癌中,TAM-FOLR2的富集可能与肺泡驻留巨噬细胞-抵抗素(ARM-RETN)的转化和树突状细胞(DCs)以及其他TAMs的招募有关[9]。
FOLR2基因的多态性与先天性心脏病(CHD)的风险降低相关。例如,母亲FOLR1基因位点rs2071010和FOLR2基因位点rs514933的多态性都与CHD风险降低相关,并且围孕期服用叶酸可以强化这些SNP对CHD的保护作用[6,7]。此外,FOLR2基因的多态性与室间隔缺损(VSD)的风险降低也相关[2]。
综上所述,Folr2基因编码的叶酸受体β在肿瘤免疫微环境和肿瘤的发生发展中起着重要作用。FOLR2基因的表达和功能与多种肿瘤相关,包括HCC、NSCLC和结直肠癌。此外,FOLR2基因的多态性与CHD和VSD的风险降低相关。Folr2基因的研究有助于深入理解肿瘤免疫微环境的调控机制和肿瘤的发生发展过程,为肿瘤的治疗和预防提供新的思路和策略。
参考文献:
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