Tsutsumi Chikanori, Ohuchida Kenoki, Tsutsumi Hirono, Shimada Yuki, Yamada Yutaka, Son Kiwa, Hayashida Sayuri, Katayama Naoki, Mochida Yuki, Iwamoto Chika, Torata Nobuhiro, Horioka Kohei, Shindo Koji, Mizuuchi Yusuke, Ikenaga Naoki, Nakata Kohei, Ota Keiichi, Iwama Eiji, Yamamoto Masami, Tsukamoto Tetsuya, Nomura Sachiyo, Morisaki Takashi, Oda Yoshinao, Okamoto Isamu, Nakamura Masafumi
Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Department of Advanced Medical Initiatives, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Cancer Lett. 2024 Dec 24;611:217412. doi: 10.1016/j.canlet.2024.217412.
Therapies targeting HER2 are the standard treatment for HER2-positive gastric cancer (GC). Trastuzumab, a monoclonal antibody against HER2, exerts anti-tumor activity through cell growth regulation and antibody-dependent cellular cytotoxicity (ADCC). ADCC is induced by the binding of trastuzumab to Fcγ receptor III (CD16) in natural killer (NK) cells. However, the relationship between immune checkpoint (IC) molecules of NK cells and trastuzumab-induced ADCC is poorly understood. We performed single-cell RNA sequencing (scRNA-seq) and immunohistochemistry to identify IC molecules associated with CD16 expression in NK cells of GC patients. Additionally, we conducted in vitro assays with HER2-transfected GC cells and in vivo experiments using a mouse HER2-positive GC model to assess expression changes in IC molecules in NK cells and their ligands during trastuzumab treatment. In GC patients, the expression of TIM3, an IC molecule, was strongly correlated with that of CD16 in NK cells. In vitro assays showed that ADCC with trastuzumab increased TIM3 expression in NK cells. scRNA-seq analysis revealed that TIM3 expression of cytotoxic NK cells was elevated in HER2-positive GC patients treated with trastuzumab. HMGB1, a TIM3 ligand, was expressed at higher levels in HER2-transfected GC cells than in controls. Furthermore, HMGB1 expression was higher in HER2-positive GC patients treated with trastuzumab compared to untreated HER2-positive GC patients. In the mouse HER2-positive GC model, anti-TIM3 antibodies and trastuzumab demonstrated synergistic anti-tumor effects without toxicity. This study suggests the combined anti-TIM3 antibody and trastuzumab therapy may have potential as a new treatment strategy for HER2-positive GC.
针对HER2的疗法是HER2阳性胃癌（GC）的标准治疗方法。曲妥珠单抗是一种抗HER2单克隆抗体，通过细胞生长调节和抗体依赖性细胞毒性（ADCC）发挥抗肿瘤活性。ADCC是由曲妥珠单抗与自然杀伤（NK）细胞中的Fcγ受体III（CD16）结合诱导产生的。然而，NK细胞的免疫检查点（IC）分子与曲妥珠单抗诱导的ADCC之间的关系尚不清楚。我们进行了单细胞RNA测序（scRNA-seq）和免疫组织化学，以鉴定GC患者NK细胞中与CD16表达相关的IC分子。此外，我们使用HER2转染的GC细胞进行了体外试验，并使用小鼠HER2阳性GC模型进行了体内实验，以评估曲妥珠单抗治疗期间NK细胞及其配体中IC分子的表达变化。在GC患者中，IC分子TIM3的表达与NK细胞中CD16的表达密切相关。体外试验表明，曲妥珠单抗介导的ADCC可增加NK细胞中TIM3的表达。scRNA-seq分析显示，接受曲妥珠单抗治疗的HER2阳性GC患者中，细胞毒性NK细胞的TIM3表达升高。TIM3配体HMGB1在HER2转染的GC细胞中的表达水平高于对照细胞。此外，与未接受治疗的HER2阳性GC患者相比，接受曲妥珠单抗治疗的HER2阳性GC患者中HMGB1的表达更高。在小鼠HER2阳性GC模型中，抗TIM3抗体和曲妥珠单抗显示出协同抗肿瘤作用且无毒性。本研究表明，联合抗TIM3抗体和曲妥珠单抗治疗可能作为HER2阳性GC的一种新治疗策略具有潜力。
