PO.TB10.16 · 肿瘤生物学
靶向Claudin 18.2的促凋亡肽用于胰腺癌早期诊断和肿瘤靶向杀伤
Claudin 18.2 targeted proapoptotic peptide for early pancreatic diagnosis and tumor-target killing
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
胰腺腺癌是一种致命性疾病，发病率不断上升，预计到2030年将成为全球第二大癌症相关死亡原因。该疾病治疗的一大障碍在于患者群体以老年人为主，且疾病临床上隐匿而具侵袭性。胰腺肿瘤的早期检测以及针对高侵袭性和转移性病变的新型治疗在胰腺肿瘤治疗中需求迫切。Claudins是紧密连接的关键组成部分。它们是跨膜蛋白，是“屏障功能”的守护者。肿瘤中的Claudins犹如被托付守卫城门却倒下的士兵。Claudin 18.2是claudin家族的一员，常在多种癌症中表达，包括胃癌和胰腺癌。癌细胞上Claudin-18.2的表达增加并暴露于细胞表面。恶性肿瘤的发展导致紧密连接破坏，使Claudin 18.2表位暴露于肿瘤细胞表面，成为一个特异性靶点。此外，Claudin 18.2随着环磷酸腺苷反应元件结合蛋白与甲基化CLDN18.2启动子区域的结合而在转录水平上调。Claudin 18.2被认为是胰腺癌发生的早期标志物。Claudin 18.2被视为抗肿瘤治疗中的一匹“黑马”。因此，Claudin 18.2可能是胰腺肿瘤早期检测和靶向特异性治疗的良好“靶点”。构建噬菌体肽库并使用过表达claudin18.2的细胞进行claudin18.2结合肽的生物淘选：经过五轮筛选，与转染细胞结合的噬菌体滴度较第一轮分离的噬菌体滴度富集程度更高。选取展示可选择性结合转染细胞肽段的2个噬菌体克隆进行测序以供进一步研究。经免疫荧光分析，这两种肽显示出对表达claudin 18.2细胞的选择性结合。pull down实验进一步证实了该肽对claudin 18.2的选择性结合。体内生物累积研究显示该肽在肿瘤组织中显著蓄积。用与促凋亡肽偶联的claudin 18.2肽处理荷KPC转基因胰腺肿瘤小鼠可提高小鼠生存率。总之，Claudin 18.2肽能够特异性靶向肿瘤细胞，与促凋亡肽偶联可诱导肿瘤靶向凋亡，并提高荷胰腺肿瘤小鼠的生存率。靶向Claudin 18.2的肿瘤杀伤可能是胰腺肿瘤治疗中一种前景广阔的方法。
查看英文原文 English abstract
Pancreatic adenocarcinoma is a lethal condition with a rising incidence, predicted to become the second leading cause of cancer-related deaths worldwide by 2030. One major hurdle in the treatment of this disease is the predominantly elderly patient population and clinically silent and aggressive nature. Early detection of pancreatic neoplasms and novel treatment for highly aggressive and metastatic conditions is of great need in pancreatic tumor therapy.Claudins are crucial components of tight junctions. They are transmembrane proteins and are the keeper of the “fence function”. Claudins in tumor are like the fall of the soldiers entrusted to protect the gate. Claudin 18.2 is a member of the claudin family, commonly expressed in multiple cancers, including Gastric cancer and Pancreatic cancer. Claudin-18.2 expression on cancer cells is increased and exposed on surface of the cells. The development of malignant tumors leads to the disruption of tight junctions, exposing the Claudin 18.2 epitope on the surface of tumor cells as a specific target. Also, claudin 18.2 is transcriptionally upregulated with the binding of cyclic AMP-responsive element binding protein to the methylated CLDN18.2 promoter region. Claudin 18.2 is considered an early stage marker of pancreatic carcinogenesis. Claudin 18.2 is considered a ‘dark horse' in anti-tumor therapy. Thus, Claudin 18.2 could be a good “target” for early detection and target-specific treatment of pancreatic tumor.Construction of phage peptide library and bio panning for claudin18.2-binding peptides using claudin18.2 overexpressing cells : After five rounds of screening, phage titers that bind to transfected cells were enriched higher-fold compared to phage titers isolated in the first round. 2 phage clones displaying peptides that selectively bound to transfected cells were chosen and sequenced for further study. The two peptides showed selective binding to claudin 18.2 expressing cells as analyzed by Immunofluorescence. Pull down assay further confirmed selective binding of peptide to claudin 18.2. Bioaccumulation study in vivo showed significant accumulation of peptide in tumor tissue. Treatment of KPC transgenic pancreatic tumor bearing mice with claudin 18.2 peptide conjugated to proapoptotic peptide enhanced the survival of the mice. In summary, Claudin 18.2 peptide can specifically target the tumor cells and conjugation with proapoptotic peptide can induce tumor targeted apoptosis with increased survival in pancreatic tumor bearing mice. Claudin 18.2 targeted tumor killing can be a promising approach for pancreatic tumor treatment.
利益披露 Disclosure
P. Sri Murugan, None.