FGFRL1 affects chemoresistance of small‐cell lung cancer by modulating the PI3K/Akt pathway via ENO1

Fibroblast growth factor receptor‐like 1 (FGFRL1), a member of the FGFR family, has been demonstrated to play important roles in various cancers. However, the role of FGFRL1 in small‐cell lung cancer (SCLC) remains unclear. Our study aimed to investigate the role of FGFRL1 in chemoresistance of SCLC and elucidate the possible molecular mechanism. We found that FGFRL1 levels are significantly up‐regulated in multidrug‐resistant SCLC cells (H69AR and H446DDP) compared with the sensitive parental cells (H69 and H446). In addition, clinical samples showed that FGFRL1 was overexpressed in SCLC tissues, and high FGFRL1 expression was associated with the clinical stage, chemotherapy response and survival time of SCLC patients. Knockdown of FGFRL1 in chemoresistant SCLC cells increased chemosensitivity by increasing cell apoptosis and cell cycle arrest, whereas overexpression of FGFRL1 in chemosensitive SCLC cells produced the opposite results. Mechanistic investigations showed that FGFRL1 interacts with ENO1, and FGFRL1 was found to regulate the expression of ENO1 and its downstream signalling pathway (the PI3K/Akt pathway) in SCLC cells. In brief, our study demonstrated that FGFRL1 modulates chemoresistance of SCLC by regulating the ENO1‐PI3K/Akt pathway. FGFRL1 may be a predictor and a potential therapeutic target for chemoresistance in SCLC.     

Interleukin‐38 protects against sepsis by augmenting immunosuppressive activity of CD4+CD25+ regulatory T cells

Naturally occurring CD4⁺CD25⁺ regulatory T cells (Tregs) are required to limit immune‐induced pathology and to maintain homeostasis during the early‐phase of sepsis. This study aimed to investigate the role of interleukin (IL)‐38, a newly described member of the IL‐1 cytokine family, in mediated immune response of CD4⁺CD25⁺ Tregs in sepsis. Here, we provide evidence that expressions of IL‐38 and its receptor were detected in murine CD4⁺CD25⁺ Tregs. Stimulation of CD4⁺CD25⁺ Tregs with LPS markedly up‐regulated the expression of IL‐38. Treatment with rmIL‐38 dramatically enhanced the immunosuppressive activity of CD4⁺CD25⁺ Tregs after LPS stimulation and in septic mice induced by CLP, resulting in amplification of helper T cell (Th) 2 response and reduction in the proliferation of effector T cells. These effects were robustly abrogated when anti–IL‐38 antibody was administered. Administration of rmIL‐38 improved the survival rate of CLP mice. In addition, CD4⁺CD25⁺ Tregs depletion before the onset of sepsis obviously abolished IL‐38–mediated protective response. These findings suggest that IL‐38 enhances the immunosuppressive activity of CD4⁺CD25⁺ Tregs, which might contribute to the improvement of host immune function and prognosis in the setting of sepsis.     

MT2A对脂多糖介导的人肺毛细血管内皮细胞损伤的保护作用

目的:探索不同浓度的金属硫蛋2A(Metallothionein 2A, MT2A)对脂多糖(Lipopolysaccharid, LPS)介导的人肺微血管内皮细胞损伤的保护作用。方法:培养人肺毛细血管内皮细胞株(Human lung microvascular endothelial cells, HPMVECs),经过一定浓度LPS溶液进行刺激后,利用不同浓度的MT2A与对照组共同培养,一段时间后观察炎性介质IL-6、TNF-α释放的量及荧光显微镜观察组HPMVECs骨架形态变化。结果:各组TNF-α浓度均在0 h最低,随之逐渐升高,到6 h达到高峰;从各时间点来看,除0 h各组TNF-α浓度无显著差异外(F=0.717, P=0.549),其余各时间点B1、B2、B3均显著高于A组(均P0.05)。各组中IL-6浓度均在0 h最低,A组在2 h达到高峰,随后逐渐下降;B1组在4 h达到高峰,随之下降;B2、B3组从0 h开始逐渐升高,到6 h达到峰值;从各时间点来看,除0 h各处理因素无显著差异外(F=2.341, P=0.092),其余各时间点B1、B2、B3均低于A组(均P0.05)。A组6 h小时后纤维状肌动蛋白(F-actin)明显解聚,分布明显减少,应力纤维排列紊乱或者消失;B1组、B2组、B3组6 h小时后,与A组相比,F-actin的分布明显较多,应力纤维排列较为整齐。结论:LPS刺激人肺毛细血管内皮细胞有明显损伤效应,加入MT2A后细胞相关炎性因子释放量、细胞骨架损伤情况明显减轻,表明一定浓度的MT2A对LPS介导的肺毛细血管损伤有明显保护作用。     

RPN2与肝癌患者预后及对肝癌细胞生长的作用

目的:探讨核糖蛋白2(ribophorin II,RPN2)在肝细胞肝癌(HCC)组织中的表达和对HCC患者生存的影响,同时分析RPN2对肝癌HepG2细胞生长和克隆形成的作用。方法:应用免疫组化方法和HCC公共芯片数据,从蛋白和m RNA水平检测HCC组织中RPN2的表达,同时分析RPN2与HCC患者临床参数的关系及预后相关性;进一步利用MTS法和克隆形成实验在肝癌HepG2细胞中检测RPN2对细胞生长的作用。结果:98例肝癌组织中,RPN2阳性表达率88.78%,对应癌旁肝组织中,RPN2阳性表达率74.49%;癌组织中RPN2染色评分为5.80±3.15,癌旁肝组织RPN2染色评分为2.13±1.59,肝癌组织中RPN2表达显著上调(P0.001)。3个肝癌公共芯片数据(共522例肝癌)中RPN2的m RNA表达水平同样显著升高(均P0.001)。98例肝癌患者RPN2表达水平与肿瘤直径(P=0.004)、门脉侵袭(P=0.012)和TNM分期(P=0.009)相关;RPN2高表达的患者总体生存期(OS)和无复发生存期(RFS)较RPN2低表达的患者短(OS:P=0.027;RFS:P=0.036)。肝癌HepG2细胞转染RPN2小干扰RNA后,细胞生长能力显著受抑制。结论:RPN2在肝癌中表达显著升高,RPN2的表达与肝癌的恶性进展有关,RPN2显著促进肝癌细胞生长。     

A novel Axin2 knock‐in mouse model for visualization and lineage tracing of WNT/CTNNB1 responsive cells

Wnt signal transduction controls tissue morphogenesis, maintenance and regeneration in all multicellular animals. In mammals, the WNT/CTNNB1 (Wnt/β‐catenin) pathway controls cell proliferation and cell fate decisions before and after birth. It plays a critical role at multiple stages of embryonic development, but also governs stem cell maintenance and homeostasis in adult tissues. However, it remains challenging to monitor endogenous WNT/CTNNB1 signaling dynamics in vivo. Here, we report the generation and characterization of a new knock‐in mouse strain that doubles as a fluorescent reporter and lineage tracing driver for WNT/CTNNB1 responsive cells. We introduced a multi‐cistronic targeting cassette at the 3′ end of the universal WNT/CTNNB1 target gene Axin2. The resulting knock‐in allele expresses a bright fluorescent reporter (3xNLS‐SGFP2) and a doxycycline‐inducible driver for lineage tracing (rtTA3). We show that the Axin2^{P2A‐rtTA3‐T2A‐3xNLS‐SGFP2} strain labels WNT/CTNNB1 responsive cells at multiple anatomical sites during different stages of embryonic and postnatal development. It faithfully reports the subtle and dynamic changes in physiological WNT/CTNNB1 signaling activity that occur in vivo. We expect this mouse strain to be a useful resource for biologists who want to track and trace the location and developmental fate of WNT/CTNNB1 responsive stem cells in different contexts.