Lopes-Rodrigues Vanessa, Di Luca Alessio, Sousa Diana, Seca Hugo, Meleady Paula, Henry Michael, Lima Raquel T, O'Connor Robert, Vasconcelos M Helena
i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; Cancer Drug Resistance Group, IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465 Porto, Portugal; ICBAS-UP - Institute of Biomedical Sciences Abel Salazar, University of Porto, 4099-003 Porto, Portugal.
NICB - National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland, UK.
Biochim Biophys Acta. 2016 Mar;1860(3):618-27. doi: 10.1016/j.bbagen.2015.12.011. Epub 2015 Dec 17.
Multidrug resistance (MDR) is a serious impediment to cancer treatment, with overexpression of drug efflux pumps such as P-glycoprotein (P-gp) playing a significant role. In spite of being a major clinical challenge, to date there is no simple, minimally invasive and clinically validated method for diagnosis of the MDR phenotype using non-tumour biological samples. Recently, P-gp has been found in extracellular vesicles (EVs) shed by MDR cancer cells. This study aimed to compare the EVs shed by MDR cells and their drug-sensitive cellular counterparts, in order to identify biomarkers of MDR.
Two pairs of MDR and drug-sensitive counterpart tumour cell lines were studied as models. EVs were characterized in terms of size and molecular markers and their protein content was investigated by proteomic analysis and Western blot.
We found that MDR cells produced more microvesicle-like EVs and less exosomes than their drug-sensitive counterpart. EVs from MDR cells contained P-gp and presented a different content of proteins known to be involved in the biogenesis of EVs, particularly in the biogenesis of exosomes.
The determination of the size and of this particular protein content of EVs shed by tumour cells may allow the development of a minimally-invasive simple method of detecting and predicting MDR.
This work describes for the first time that cancer multidrug resistant cells shed more microvesicle-like EVs and less exosomes than their drug-sensitive counterpart cells, carrying a specific content of proteins involved in EV biogenesis that could be further studied as biomarkers of MDR.
多药耐药（MDR）是癌症治疗的严重障碍，药物外排泵如P-糖蛋白（P-gp）的过表达起重要作用。尽管这是一个重大临床挑战，但迄今为止，尚无使用非肿瘤生物样本诊断MDR表型的简单、微创且经过临床验证的方法。最近，在MDR癌细胞释放的细胞外囊泡（EVs）中发现了P-gp。本研究旨在比较MDR细胞与其药物敏感的对应细胞释放的EVs，以鉴定MDR的生物标志物。
以两对MDR和药物敏感的对应肿瘤细胞系为模型进行研究。对EVs的大小和分子标志物进行表征，并通过蛋白质组学分析和蛋白质印迹研究其蛋白质含量。
我们发现，与药物敏感的对应细胞相比，MDR细胞产生更多微泡样EVs，而外泌体较少。来自MDR细胞的EVs含有P-gp，并且呈现出已知参与EVs生物发生，特别是外泌体生物发生的蛋白质的不同含量。
确定肿瘤细胞释放的EVs的大小和这种特定蛋白质含量，可能有助于开发一种检测和预测MDR的微创简单方法。
这项工作首次描述了癌症多药耐药细胞比其药物敏感的对应细胞释放更多微泡样EVs，而外泌体较少，携带参与EV生物发生的特定蛋白质含量，可作为MDR的生物标志物进一步研究。
