Marquez Jorge, Dong Jianping, Yue Binbin, Hayashi Jun, Dong Chun, Oshimura Mitsuo, Serrero Ginette
Department of Pharmaceutical Sciences, University of Maryland, Baltimore School of Pharmacy, Baltimore, Maryland, USA.
Target Discovery Division, A&G Pharmaceutical, Inc., Columbia, Maryland, USA.
J Cell Mol Med. 2025 Jun;29(12):e70665. doi: 10.1111/jcmm.70665.
Antibody Drug Conjugates (ADCs) are attractive for developing cancer-targeted therapies, particularly for cancers with unmet needs. Identification of a druggable internalising cell-surface target enables the development of internalising monoclonal antibodies to deliver toxic payloads directly to the cancer cells. Using immunohistochemistry, we screened various non-cancerous and cancerous tissue sections to assess PTGFRN expression levels. We produced hybridoma lines that produce fully human antibodies against the PTGFRN extracellular domain. After screening, we conjugated the cytotoxic payload Duocarmycin to an antibody candidate and tested its efficacy in in vitro assays, as well as in vivo xenografted athymic nude mice. We showed that PTGFRN expression was undetectable in non-cancerous tissue samples and overexpressed in several patient-derived cancer tissue samples. We produced a hybridoma line that produces a fully human IgG1 (8C7) against PTGFRN. 8C7 binds to cell-surface PTGFRN, inducing endocytosis of PTGFRN. Direct conjugation of Duocarmycin to 8C7 resulted in an antibody-drug conjugate that showed high potency in in vitro and in vivo models for three PTGFRN-expressing cell lines examined, A431, DAOY, and MSTO, while it had no effect on PTGFRN-negative MDA-MB-231. 8C7-ADC administered via intraperitoneal injection to xenografted mice showed inhibition of tumour formation and growth with no effect on body weight and organ weights. These findings further validate PTGFRN as a target for antibody-drug conjugate development for cancers with unmet needs.
抗体药物偶联物（ADCs）在开发癌症靶向治疗药物方面具有吸引力，尤其是针对那些尚未满足需求的癌症。鉴定出可药物作用的内化细胞表面靶点，能够开发出内化单克隆抗体，将毒性载荷直接递送至癌细胞。我们利用免疫组织化学技术，筛选了各种非癌组织和癌组织切片，以评估PTGFRN的表达水平。我们制备了能产生针对PTGFRN胞外结构域的全人源抗体的杂交瘤细胞系。筛选后，我们将细胞毒性载荷多卡霉素偶联到一个候选抗体上，并在体外试验以及体内异种移植无胸腺裸鼠模型中测试其疗效。我们发现，在非癌组织样本中检测不到PTGFRN的表达，而在一些患者来源的癌组织样本中PTGFRN过表达。我们制备了一个能产生针对PTGFRN的全人源IgG1（8C7）的杂交瘤细胞系。8C7能结合细胞表面的PTGFRN，诱导PTGFRN的内吞作用。将多卡霉素直接偶联到8C7上，得到了一种抗体药物偶联物，在体外和体内模型中，该偶联物对所检测的三种表达PTGFRN的细胞系A431、DAOY和MSTO显示出高效力，而对PTGFRN阴性的MDA-MB-231细胞系没有影响。通过腹腔注射给予异种移植小鼠8C7-ADC，显示出对肿瘤形成和生长的抑制作用，且对体重和器官重量没有影响。这些发现进一步验证了PTGFRN作为针对未满足需求的癌症的抗体药物偶联物开发靶点的有效性。
