在基于RM2的GRPR配体中对Gln-Trp位点的修改影响的研究
Sebastian Fischer1, Lena Koller1, Sandra Dominelli1
1TUM School of Natural Sciences, Department of Chemistry, Chair of Pharmaceutical Radiochemistry, Technical University of Munich, 85748, Garching, Germany.
EJNMMI research
|September 1, 2025
概括
使用非自然氨基酸修改胃素释放受体 (GRPR) 配体RM2会影响其稳定性和药物动力学特性. α- 甲基- L- 氨酸类似物在体内稳定性得到改善,增强了其针对GRPR成像和治疗的潜力.
科学领域:
- 放射性药物化学
- 分子成像
- 癌症学
背景情况:
- 胃释放受体 (GRPR) 配体在临床前和临床癌症研究中至关重要.
- 这种RM2抗是一种已被充分研究的GRPR配体.
- 研究RM2中的非自然氨基酸替代旨在改善其体内稳定性和药物动力学特征.
研究的目的:
- 评估非自然氨基酸 (同素,β-3-乙烯,α-甲基-L-) 在RM2的Gln-Trp位点的影响.
- 评估不同合剂 (DOTA,NOTA,NODAGA) 对RM2模拟性能的影响.
- 使用各种放射性金属 (Ga,Cu,Lu) 评估新型RM2衍生物的临床前疗效.
主要方法:
- 用非自然氨基酸和剂合成和放射性标记RM2衍生物.
- 使用68Ga,64Cu和177Lu进行临床前评估.
- 在瘤模型中评估GRPR亲和力,脂性,体内稳定性和生物分布.
主要成果:
- RM2衍生品在纳米分子范围内表现出GRPR亲缘关系.
- 与其他类型相比,α- 甲基- L- 托芬类型 ([177Lu]Lu- AMTG) 在体内稳定性显著更高.
- [68 Ga-AMTG 和 [68 Ga-RM2 的瘤吸收率较高,而 [68 Ga-[Hse7] RM2 和 [68 Ga-[Bta8] RM2 的瘤和胰腺吸收率较低.
- 在注射后24小时,Lu标记的AMTG和RM2显示出高瘤保留率.
结论:
- 用非自然氨基酸替代 Gln- Trp 位点显然会影响 RM2 的药理动力学.
- 替代α-甲基-L-氨酸增强了体内稳定性,并改善了药物动力学特性.
- 荷莫塞林和β-3-乙烯替代可能为优化成像特性提供改善的瘤与背景比率.
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