Fascaplysin 是一种从海洋海绵 Fascaplysinopsis sp 中分离出来的具有抗癌特性的红色细胞毒性色素。最近，我们课题组报告的构效关系分析表明，fascaplysin 衍生物对肿瘤细胞的选择性细胞毒性与其插入 DNA 的能力呈负相关。为了验证这一假设，我们合成了 6- 和 7-叔丁基 fascaplysins，其揭示了减轻的 DNA 嵌入特性。这些衍生物被发现对耐药人类前列腺癌细胞具有强烈的细胞毒性，尽管与 fascaplysin 相比，它们对癌细胞的选择性没有改善。同时，激酶组分析表明，在药物暴露后不久，癌细胞中的 CHK1/ATR 轴被激活。进一步的实验揭示了复制应激的诱导，最终转化为有毒的 DNA 双链断裂，导致不依赖 caspase 的细胞凋亡样细胞死亡。我们的观察强调了一些 fascaplysin 衍生物的新 DNA 靶向作用，并表明 fascaplysin 家族内更复杂的结构-活性关系，表明这些生物碱的细胞毒性和选择性受到多种因素的影响。此外，进一步研究应考虑与临床批准的 ATR/CHK1 抑制剂组合以及对 DNA 损伤特别敏感的肿瘤进行测试。© 2024。作者。

Fascaplysin is a red cytotoxic pigment with anticancer properties isolated from the marine sponge Fascaplysinopsis sp. Recently, structure-activity relationship analysis reported by our group suggested that selective cytotoxicity of fascaplysin derivatives towards tumor cells negatively correlates with their ability to intercalate into DNA. To validate this hypothesis, we synthesized 6- and 7-tert-butylfascaplysins which reveal mitigated DNA-intercalating properties. These derivatives were found to be strongly cytotoxic to drug-resistant human prostate cancer cells, albeit did not demonstrate improved selectivity towards cancer cells when compared to fascaplysin. At the same time, kinome analysis suggested an activation of CHK1/ATR axis in cancer cells shortly after the drug exposure. Further experiments revealed induction of replication stress that is eventually converted to the toxic DNA double-strand breaks, resulting in caspase-independent apoptosis-like cell death. Our observations highlight new DNA-targeting effect of some fascaplysin derivatives and indicate more complex structure-activity relationships within the fascaplysin family, suggesting that cytotoxicity and selectivity of these alkaloids are influenced by multiple factors. Furthermore, combination with clinically-approved inhibitors of ATR/CHK1 as well as testing in tumors particularly sensitive to the DNA damage should be considered in further studies.© 2024. The Author(s).