Higashi Yuya, Ikeda Shuji, Matsumoto Kotaro, Satoh Shinsuke, Komatsu Aoi, Sugiyama Hiroshi, Tamanoi Fuyuhiko
Institute for Integrated Cell-Material Sciences, Institute for Advanced Study, Kyoto University, Kyoto 606-8501, Japan.
Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Cancers (Basel). 2022 Feb 14;14(4):951. doi: 10.3390/cancers14040951.
The KRAS inhibitor KR12, based on pyrrole-imidazole polyamide (PIP), has been developed and shown to exhibit efficacy in mouse experiments. Because some PIP species exhibit tumor accumulation capability, we decided to evaluate whether the PIP portion of KR12 exhibits tumor accumulation. We employed the CAM assay that provides a simple method for tumor accumulation evaluation.
KR12 PIP was synthesized and conjugated to TAMRA to produce a fluorescently labeled reagent (KR12-TAMRA). This reagent was injected into a fertilized chicken egg that has been transplanted with human cancer cells. Distribution of the red fluorescence was examined by cutting out tumor as well as various organs from the embryo.
The red fluorescence of KR12-TAMRA was found to overlap with the green fluorescence of the tumor formed with GFP-expressing cancer cells. We also observed nuclear localization of KR12-TAMRA. Treatment of KR12 that contained the alkylating agent CBI in the tumor-bearing chicken egg resulted in tumor growth inhibition.
KR12 contains a PIP that has two key features: tumor accumulation and nuclear localization. KR12 conjugated with CBI exhibits inhibition of tumor growth in the CAM model.
基于吡咯-咪唑聚酰胺（PIP）的KRAS抑制剂KR12已被研发出来，并在小鼠实验中显示出疗效。由于某些PIP种类具有肿瘤蓄积能力，我们决定评估KR12的PIP部分是否具有肿瘤蓄积性。我们采用了鸡胚绒毛尿囊膜（CAM）实验，该实验为肿瘤蓄积评估提供了一种简单的方法。
合成KR12 PIP并与四甲基罗丹明（TAMRA）偶联，制备出一种荧光标记试剂（KR12-TAMRA）。将该试剂注射到已移植人癌细胞的受精鸡蛋中。通过从胚胎中切下肿瘤以及各种器官，检查红色荧光的分布情况。
发现KR12-TAMRA的红色荧光与表达绿色荧光蛋白（GFP）的癌细胞形成的肿瘤的绿色荧光重叠。我们还观察到KR12-TAMRA的核定位。在荷瘤鸡蛋中用含有烷基化剂CBI的KR12进行处理，导致肿瘤生长受到抑制。
KR12含有一种具有两个关键特性的PIP：肿瘤蓄积和核定位。与CBI偶联的KR12在CAM模型中表现出对肿瘤生长的抑制作用。
