Institute of Biomedical Research of Salamanca (IBSAL), Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain.
Department of Pathology and IBSAL, University Hospital of Salamanca, Salamanca, Spain.
J Exp Clin Cancer Res. 2023 Aug 9;42(1):200. doi: 10.1186/s13046-023-02784-0.
Advanced colorectal cancer (CRC) is difficult to treat. For that reason, the development of novel therapeutics is necessary. Here we describe a potentially actionable plasma membrane target, the amino acid transporter protein subunit CD98hc.
Western blot and immunohistochemical analyses of CD98hc protein expression were carried out on paired normal and tumoral tissues from patients with CRC. Immunofluorescence and western studies were used to characterize the action of a DM1-based CD98hc-directed antibody-drug conjugate (ADC). MTT and Annexin V studies were performed to evaluate the effect of the anti-CD98hc-ADC on cell proliferation and apoptosis. CRISPR/Cas9 and shRNA were used to explore the specificity of the ADC. In vitro analyses of the antitumoral activity of the anti-CD98hc-ADC on 3D patient-derived normal as well as tumoral organoids were also carried out. Xenografted CRC cells and a PDX were used to analyze the antitumoral properties of the anti-CD98hc-ADC.
Genomic as well proteomic analyses of paired normal and tumoral samples showed that CD98hc expression was significantly higher in tumoral tissues as compared to levels of CD98hc present in the normal colonic tissue. In human CRC cell lines, an ADC that recognized the CD98hc ectodomain, reached the lysosomes and exerted potent antitumoral activity. The specificity of the CD98hc-directed ADC was demonstrated using CRC cells in which CD98hc was decreased by shRNA or deleted using CRISPR/Cas9. Studies in patient-derived organoids verified the antitumoral action of the anti-CD98hc-ADC, which largely spared normal tissue-derived colon organoids. In vivo studies using xenografted CRC cells or patient-derived xenografts confirmed the antitumoral activity of the anti-CD98hc-ADC.
The studies herewith reported indicate that CD98hc may represent a novel ADC target that, upon well-designed clinical trials, could be used to increase the therapeutic armamentarium against CRC.
晚期结直肠癌（CRC）难以治疗。因此，有必要开发新的治疗方法。在这里，我们描述了一个潜在的可作用于细胞膜的靶点，即氨基酸转运蛋白亚基 CD98hc。
对来自 CRC 患者的配对正常和肿瘤组织进行 CD98hc 蛋白表达的 Western blot 和免疫组织化学分析。采用免疫荧光和 Western 研究来描述基于 DM1 的 CD98hc 导向抗体药物偶联物（ADC）的作用。通过 MTT 和 Annexin V 研究评估抗 CD98hc-ADC 对细胞增殖和凋亡的影响。使用 CRISPR/Cas9 和 shRNA 探索 ADC 的特异性。还对 3D 患者来源的正常和肿瘤类器官上抗 CD98hc-ADC 的抗肿瘤活性进行了体外分析。使用异种移植的 CRC 细胞和 PDX 分析抗 CD98hc-ADC 的抗肿瘤特性。
配对的正常和肿瘤样本的基因组和蛋白质组分析表明，与正常结肠组织中的 CD98hc 水平相比，肿瘤组织中 CD98hc 的表达显著更高。在人 CRC 细胞系中，一种识别 CD98hc 胞外结构域的 ADC 可到达溶酶体并发挥强大的抗肿瘤活性。使用 shRNA 降低 CRC 细胞中的 CD98hc 或使用 CRISPR/Cas9 缺失 CD98hc，证明了 CD98hc 定向 ADC 的特异性。在患者来源的类器官中进行的研究验证了抗 CD98hc-ADC 的抗肿瘤作用，该作用在很大程度上保留了源自正常组织的结肠类器官。使用异种移植的 CRC 细胞或患者来源的异种移植进行的体内研究证实了抗 CD98hc-ADC 的抗肿瘤活性。
本研究报告表明，CD98hc 可能代表一个新的 ADC 靶点，经过精心设计的临床试验后，可用于增加 CRC 的治疗手段。
