Ruffilli Camilla, Röth Sascha, Zelcer Noam, Moreau Kevin
Safety Innovation and PROTAC Safety, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, CB2 0SL, UK.
Department of Medical Biochemistry, Amsterdam UMC, University of Amsterdam, 1000 GG, Amsterdam, The Netherlands.
Sci Rep. 2025 Jan 2;15(1):504. doi: 10.1038/s41598-024-84217-2.
Dysregulation of integral membrane proteins (IMPs) has been linked to a myriad of diseases, making these proteins an attractive target in drug research. Whilst PROTAC technology has had a significant impact in scientific research, its application to IMPs is still limited. Limitations of the traditional approach of immunoblotting in PROTAC research include the low throughput compared to other methods, as well as a lack of spatial information for the target. Here we compare orthogonal antibody based approaches, i.e. immunoblotting, flow cytometry and immunofluorescence, to measure PROTAC mediated degradation of two established, endogenous targets, epidermal growth factor receptor (EGFR) and hepatocyte growth-factor receptor (c-MET). We discuss advantages and limitations of each methodology for the assessment of PROTAC efficacy on IMPs. Overall, we recommend the use of immunofluorescence and flow cytometry, for an increased accuracy with both a qualitative and quantitative insight into degradation efficacy and a critical distinction between cell membrane-localized and intracellular IMP protein pools.
整合膜蛋白（IMPs）的失调与多种疾病相关，这使得这些蛋白成为药物研究中一个有吸引力的靶点。虽然PROTAC技术在科学研究中产生了重大影响，但其在IMPs方面的应用仍然有限。PROTAC研究中传统免疫印迹方法的局限性包括与其他方法相比通量较低，以及缺乏靶点的空间信息。在这里，我们比较基于正交抗体的方法，即免疫印迹、流式细胞术和免疫荧光，以测量PROTAC介导的两种已确立的内源性靶点——表皮生长因子受体（EGFR）和肝细胞生长因子受体（c-MET）的降解。我们讨论了每种方法在评估PROTAC对IMPs疗效方面的优缺点。总体而言，我们建议使用免疫荧光和流式细胞术，以提高准确性，对降解疗效进行定性和定量洞察，并明确区分细胞膜定位的和细胞内的IMPs蛋白池。
