Department of Cell Systems & Anatomy, University of Texas Health Science Center at San Antonio, TX, United States of America; Department of Clinical Laboratory, Qilu Hospital of Shandong University, China.
Department of Cell Systems & Anatomy, University of Texas Health Science Center at San Antonio, TX, United States of America.
Life Sci. 2024 Nov 15;357:123103. doi: 10.1016/j.lfs.2024.123103. Epub 2024 Sep 30.
Ficolin 3 (FCN3) has the highest complement-activating capacity through the lectin pathway and is synthesized mainly in the liver and lung. Yet, its potential molecular mechanism in hepatocarcinogenesis is not fully understood.
The expression of FCN3 in hepatocellular carcinoma (HCC) tumor and non-tumor tissues was analyzed by RT-qPCR, Western blotting and immunofluorescence staining assays. Lentivector-mediated ectopic overexpression was performed to explore the role of FCN3 in vitro and in vivo. Whether FCN3 inhibited HCC cell growth and survival via complement pathway was determined with immunocytochemical staining for C3b, membrane attack complex (MAC) formation and complement killing assay using recombinant FCN3 (rFCN3) in combination with human serum with or without heat inactivation, and with C6 blocking antibody.
The transcript and protein of FCN3 were found to be remarkably down-regulated in HCC tumor tissues. FCN3 expression was found to be associated with better survival of HCC patients. Restoration of FCN3 expression significantly inhibited proliferation, migration and anchorage independent growth of HCC cell lines, and xenograft tumor growth. FCN3 expression induced apoptosis of HCC cells. C3 and MAC formation was stimulated by FCN3 overexpression or rFCN3 treatment. rFCN3 enhanced human serum-induced complement activation and cell death. C6 blocking antibody significantly attenuated complement-mediated cell death and restored the growth of FCN3-overexpressing HCC cells.
FCN3 has a malignant suppressor role in HCC cells. Our study provides new insights into the molecular mechanisms that drive HCC progression and potential therapeutic targets for treating HCC.
ficolin-3（FCN3）通过凝集素途径具有最高的补体激活能力，主要在肝脏和肺部合成。然而，其在肝癌发生中的潜在分子机制尚不完全清楚。
通过 RT-qPCR、Western blot 和免疫荧光染色分析肝癌（HCC）肿瘤和非肿瘤组织中 FCN3 的表达。通过慢病毒介导的异位过表达来探索 FCN3 在体外和体内的作用。通过用重组 FCN3（rFCN3）与含有或不含热失活的人血清联合进行免疫细胞化学染色以检测 C3b、膜攻击复合物（MAC）形成以及补体杀伤试验，以及用 C6 阻断抗体，来确定 FCN3 是否通过补体途径抑制 HCC 细胞的生长和存活。
FCN3 的转录本和蛋白在 HCC 肿瘤组织中明显下调。FCN3 的表达与 HCC 患者的更好生存相关。FCN3 表达的恢复显著抑制了 HCC 细胞系的增殖、迁移和锚定非依赖性生长以及异种移植肿瘤的生长。FCN3 表达诱导 HCC 细胞凋亡。FCN3 过表达或 rFCN3 处理可刺激 C3 和 MAC 形成。rFCN3 增强人血清诱导的补体激活和细胞死亡。C6 阻断抗体可显著减弱补体介导的细胞死亡并恢复 FCN3 过表达 HCC 细胞的生长。
FCN3 在 HCC 细胞中具有恶性抑制作用。我们的研究为驱动 HCC 进展的分子机制提供了新的见解，并为治疗 HCC 提供了潜在的治疗靶点。
