Vaeteewoottacharn Kulthida, Waraasawapati Sakda, Pothipan Phattarin, Kariya Ryusho, Saisomboon Saowaluk, Bunthot Supawadee, Pairojkul Chawalit, Sawanyawisuth Kanlayanee, Kuwahara Kazuhiko, Wongkham Sopit, Okada Seiji
Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand; Division of Hematopoiesis, Joint Research Center for Human Retrovirus Infection and Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-0811, Japan.
Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Exp Mol Pathol. 2024 Dec;140:104935. doi: 10.1016/j.yexmp.2024.104935. Epub 2024 Sep 27.
Immune evasion is one of the mechanisms by which cancer cells acquire immunity during cancer development and progression. One of these is the increased expression of cluster of differentiation 47 (CD47), a transmembrane glycoprotein that protects cells from phagocytic elimination. The interaction between CD47 and signal regulatory protein alpha (SIRPα) on macrophages alleviates the phagocytic signal. The present group previously reported high CD47 expression in cholangiocarcinoma (CCA), a major health problem in Thailand and East Asia, and that blocking CD47 using anti-CD47 antibodies promoted the removal of CCA. However, the mechanism through which CD47 inhibition attenuates CCA growth remains unclear. This study explored the clinical significance of targeting CD47 in CCA. Expression levels of CD47 and the macrophage marker CD68 were determined in CCA tissues by immunohistochemistry and correlated with clinical parameters. The role of CD47 in CCA cells was established using CD47-deficient KKU-213A CCA clones in vitro and in vivo. The results showed that CD47 was highly expressed in CCA tissues and significantly correlated with lymph node metastasis (P = 0.038). Moderate-to-dense CD68-positive infiltrating cells in CCA tissues were significantly associated with shorter survival of patients (P = 0.019) and were an independent prognostic factor of CCA patients as determined by the Cox proportional hazard model (hazard ratio, 2.040; 95 % confidence interval, 1.109-3.752; P = 0.022). Three CD47-deficient KKU-213A clones (#19, #23, and #28) were generated. The elimination of CD47 did not affect cell proliferation but increased monocyte-derived macrophage-mediated phagocytosis in vitro. Decreased tumor weights and volumes were observed in mice injected with CD47-deficient CCA clones. This revealed a significant role for CD47 in CCA, with a focus on protecting cancer cells from macrophage phagocytosis.
免疫逃逸是癌细胞在癌症发生发展过程中获得免疫的机制之一。其中之一是分化簇47（CD47）表达增加，CD47是一种跨膜糖蛋白，可保护细胞免受吞噬清除。CD47与巨噬细胞上的信号调节蛋白α（SIRPα）之间的相互作用减轻了吞噬信号。本研究小组之前报道，在泰国和东亚地区的主要健康问题——胆管癌（CCA）中，CD47表达较高，并且使用抗CD47抗体阻断CD47可促进CCA的清除。然而，CD47抑制减弱CCA生长的机制仍不清楚。本研究探讨了靶向CD47在CCA中的临床意义。通过免疫组织化学测定CCA组织中CD47和巨噬细胞标志物CD68的表达水平，并将其与临床参数相关联。使用CD47缺陷的KKU-213A CCA克隆在体外和体内确定CD47在CCA细胞中的作用。结果显示，CD47在CCA组织中高表达，且与淋巴结转移显著相关（P = 0.038）。CCA组织中中度至密集的CD68阳性浸润细胞与患者较短的生存期显著相关（P = 0.019），并且根据Cox比例风险模型确定，是CCA患者的独立预后因素（风险比，2.040；95%置信区间，1.109 - 3.752；P = 0.022）。生成了三个CD47缺陷的KKU-213A克隆（#19、#23和#28）。CD47的消除不影响细胞增殖，但在体外增加了单核细胞衍生巨噬细胞介导的吞噬作用。在注射了CD47缺陷CCA克隆的小鼠中观察到肿瘤重量和体积减小。这揭示了CD47在CCA中的重要作用，重点是保护癌细胞免受巨噬细胞吞噬。
