Xu Li, Zhou Bin, Jin Kaiqi, Ge Tao, Deng Ming, Ding Hongdou, Xu Xinnan
Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai , China.
Shanghai Pulmonary Hospital, Tongji University School of Medicine, Department of Thoracic Surgery, Shanghai, China;
Am J Respir Cell Mol Biol. 2025 May 9. doi: 10.1165/rcmb.2024-0648OC.
Gap junction protein beta 2 (GJB2) has been associated with glycolysis and immunosuppression in human tumors. This research aims to explore the roles of GJB2 in these aspects in the context of lung adenocarcinoma (LUAD). GJB2 expression in LUAD was analyzed using bioinformatics tools and verified in human LUAD cells. RNA binding proteins (RBPs) that target GJB2 were predicted using bioinformatics and verified using RNA immunoprecipitation assays. Gain- or loss-of-function assays of GJB2 and high-density lipoprotein binding protein (HDLBP) were performed in LUAD cells, investigating their roles in glycolysis. These LUAD cells underwent co-culture with activated CD8 T cells to examine the effect of gene interference on the exhaustion and activity of T cells. A mouse model of allograft tumor was established for validation. GJB2 exhibited aberrantly heightened expression in LUAD cells. Further overexpression of GJB2 in cancer cells increased glucose uptake, lactate production, and extracellular acidification rate, augmented aggressive phenotype of cancer cells, and increased exhaustion of the co-cultured CD8 T cells. HDLBP, an RBP that binds to GJB2 RNA, was found to be highly expressed in LUAD as well, which enhanced GJB2 expression by stabilizing the GJB2 mRNA. Overexpression of HDLBP similarly rendered glycolysis and T cell inactivity, with these effects negated by GJB2 knockdown. Parallelly, GJB2 silencing in mouse 3LL cells suppressed tumorigenesis, glycolysis, and T cell exhaustion in mice promoted by HDLBP. This research suggests that HDLBP-mediated GJB2 RNA stabilization augments glycolysis and CD8 T cell exhaustion in LUAD progression.
缝隙连接蛋白β2（GJB2）已被证明与人类肿瘤中的糖酵解和免疫抑制有关。本研究旨在探讨GJB2在肺腺癌（LUAD）背景下在这些方面的作用。使用生物信息学工具分析了LUAD中GJB2的表达，并在人LUAD细胞中进行了验证。使用生物信息学预测靶向GJB2的RNA结合蛋白（RBP），并通过RNA免疫沉淀试验进行验证。在LUAD细胞中进行了GJB2和高密度脂蛋白结合蛋白（HDLBP）的功能获得或缺失试验，研究它们在糖酵解中的作用。将这些LUAD细胞与活化的CD8 T细胞共培养，以检查基因干扰对T细胞耗竭和活性的影响。建立了同种异体移植肿瘤小鼠模型进行验证。GJB2在LUAD细胞中表现出异常高表达。癌细胞中GJB2的进一步过表达增加了葡萄糖摄取、乳酸产生和细胞外酸化率，增强了癌细胞的侵袭性表型，并增加了共培养的CD8 T细胞的耗竭。HDLBP是一种与GJB2 RNA结合的RBP，在LUAD中也高表达，它通过稳定GJB2 mRNA来增强GJB2表达。HDLBP的过表达同样导致糖酵解和T细胞无活性，而GJB2敲低可消除这些作用。同时，在小鼠3LL细胞中沉默GJB2可抑制HDLBP促进的小鼠肿瘤发生、糖酵解和T细胞耗竭。本研究表明，HDLBP介导的GJB2 RNA稳定增强了LUAD进展中的糖酵解和CD8 T细胞耗竭。
