De Florian Fania Rossella, Maiocchi Serena, Klima Raffaella, Rossin Monica, Pellegrini Valeria, Ghetti Sabrina, Selvestrel Davide, Mattevi Maria Chiara, Fava Luca L, Braga Luca, Collavin Licio
Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy.
International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano 99, 34149 Trieste, Italy.
Biomolecules. 2025 Aug 8;15(8):1147. doi: 10.3390/biom15081147.
The tumor suppressor DAB2IP, a RasGAP and cytoplasmic adaptor protein, modulates signal transduction in response to several extracellular stimuli, negatively regulating multiple oncogenic pathways. Accordingly, the loss of DAB2IP in tumor cells fosters metastasis and enhances chemo- and radioresistance. DAB2IP is rarely mutated in cancer but is frequently downregulated or inactivated by multiple mechanisms. Solid experimental evidence shows that DAB2IP reactivation reduces cancer aggressiveness in tumors driven by multiple different oncogenic mutations, making this protein an interesting target for cancer therapy. Considering this evidence, we screened a drug library to identify molecules that increase DAB2IP protein levels. We employed CRISPR/Cas9 gene editing to generate two prostate cancer cell models in which endogenous DAB2IP is fused to HiBiT, a peptide tag that enables luminescence-based detection of protein levels in a sensitive and quantitative manner. Using this approach, we identified drugs able to increase DAB2IP levels. We focused our attention on thiostrepton, a natural cyclic oligopeptide antibiotic that has been reported to inhibit the survival of various cancer cell lines. Functional experiments revealed that the cancer-inhibitory effect of thiostrepton is reduced in the absence of DAB2IP, suggesting that upregulation of this protein contributes to its action. These findings encourage further development of thiostrepton for the treatment of solid cancers and unveil a novel molecular target underlying its anti-tumoral activity.
肿瘤抑制因子DAB2IP是一种RasGAP和细胞质衔接蛋白，可响应多种细胞外刺激调节信号转导，对多种致癌途径起负调控作用。因此，肿瘤细胞中DAB2IP的缺失会促进转移并增强化疗和放疗抗性。DAB2IP在癌症中很少发生突变，但经常通过多种机制下调或失活。确凿的实验证据表明，DAB2IP的重新激活可降低由多种不同致癌突变驱动的肿瘤的癌症侵袭性，使该蛋白成为癌症治疗的一个有吸引力的靶点。基于这一证据，我们筛选了一个药物库，以鉴定能提高DAB2IP蛋白水平的分子。我们采用CRISPR/Cas9基因编辑技术构建了两种前列腺癌细胞模型，其中内源性DAB2IP与HiBiT融合，HiBiT是一种肽标签，能够以灵敏且定量的方式基于发光检测蛋白水平。利用这种方法，我们鉴定出了能够提高DAB2IP水平的药物。我们将注意力集中在硫链丝菌素上，它是一种天然的环状寡肽抗生素，据报道可抑制多种癌细胞系的存活。功能实验表明，在缺乏DAB2IP的情况下，硫链丝菌素的癌症抑制作用会降低，这表明该蛋白的上调有助于其发挥作用。这些发现鼓励进一步开发硫链丝菌素用于实体癌的治疗，并揭示了其抗肿瘤活性背后的一个新的分子靶点。
