Boudreau Matthew W, Freire Vitor F, Corbett Sophie C, Martínez-Fructuoso Lucero, Kumar Rohitesh, Thornburg Christopher C, Akee Rhone K, Peyser Brian D, Jiang Qinqin, Splaine Jennifer, Pfaff Jamie L, Chandler Benjamin C, Abeja Dinah M, Donovan Katherine A, Che Jianwei, Lampson Benjamin L, Szajner Patricia, Smith Jennifer A, Koduri Vidyasagar, Grkovic Tanja, O'Keefe Barry R, Kaelin William G
Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA.
Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA.
bioRxiv. 2025 Aug 27:2025.08.27.671140. doi: 10.1101/2025.08.27.671140.
Cell-based phenotypic screening of natural product mixtures can reveal new biological and pharmacological principles but has been largely abandoned, partly because such mixtures can be difficult to deconvolute and often contain toxins that confound "down" assays. We reasoned that these concerns could be partly mitigated by screening prefractionated natural product mixtures in cell-based "up" assays. We tested 326,304 natural product mixtures (40,744 extracts and 285,560 fractions derived from them) in a high throughput screen using mammalian cells expressing an oncogenic version of β-catenin (β-cat) fused to a suicide protein. Multiple fractions degraded the β-cat fusion protein or drove it into a compartment where both fusion partners were apparently inactive. The active compound from one of the latter specifically activates novel, but not classical, protein kinase Cs (PKCs) and thereby relocates β-cat to juxtamembrane vacuolar structures. These findings suggest a path for inactivating oncogenic β-cat and underscore the power of natural product screening.
基于细胞的天然产物混合物表型筛选可以揭示新的生物学和药理学原理，但在很大程度上已被放弃，部分原因是此类混合物可能难以解析，且通常含有会干扰“下游”检测的毒素。我们推断，通过在基于细胞的“上游”检测中筛选预分级的天然产物混合物，这些问题可以得到部分缓解。我们在高通量筛选中测试了326,304种天然产物混合物（40,744种提取物及其衍生的285,560个馏分），该筛选使用了表达与自杀蛋白融合的致癌形式β-连环蛋白（β-cat）的哺乳动物细胞。多个馏分降解了β-cat融合蛋白，或将其驱动到一个融合伴侣显然均无活性的区室中。来自后者之一的活性化合物特异性激活新型而非经典的蛋白激酶C（PKC），从而将β-cat重新定位到近膜液泡结构。这些发现提示了一条使致癌性β-cat失活的途径，并强调了天然产物筛选的作用。
