Ning Kuan, Wang Teng, Sun Xu, Zhang Pengfei, Chen Yun, Jin Jian, Hua Dong
Department of Oncology, Affiliated Hospital of Jiangnan University and the Fourth People's Hospital of Wuxi, Wuxi, Jiangsu, China.
Wuxi Medical College, Jiangnan University, Wuxi, Jiangsu, China.
J Surg Oncol. 2017 Jun;115(8):932-940. doi: 10.1002/jso.24614. Epub 2017 Mar 23.
Chemotherapy resistance has become a serious challenge in the treatment of breast cancer. Previous studies showed cells can transfer proteins, including those responsible for drug resistance to adjacent cells via exosomes.
The switches of drug resistance via exosomes transfer were assessed by CellTiter-Blue Viability assay, flow cytometry, and immunostaining analysis. Relative protein levels of Ubiquitin carboxyl terminal hydrolase-L1 (UCH-L1), P-glycoprotein (P-gp), extracellular-signal regulated protein kinase1/2 (ERK1/2), and phospho-extracellular-signal regulated protein kinase1/2 (p-ERK1/2) were measured by Western blot. Immunohistochemistry was performed on 93 breast cancer samples to assess the associations of UCH-L1 levels with immunofluorescence value of UCH-L1 in circulating exosomes.
The Adriamycin-resistant human breast cancer cells (MCF7/ADM) secreted exosomes carrying UCH-L1 and P-gp proteins into the extracellular microenvironment then integrated into Adriamycin-sensitive human breast cancer cells (MCF7/WT) in a time-dependent manner, transferring the chemoresistance phenotype. Notably, in blood samples from patients with breast cancer, the level of exosomes carrying UCH-L1 before chemotherapy was significantly negatively correlated with prognosis.
Our study demonstrated that UCH-L1-containing exosomes can transfer chemoresistance to recipient cells and these exosomes may be useful as non-invasive diagnostic biomarkers for detection of chemoresitance in breast cancer patients, achieving more effective and individualized chemotherapy.
化疗耐药已成为乳腺癌治疗中的一项严峻挑战。既往研究表明，细胞可通过外泌体将蛋白质（包括那些与耐药性相关的蛋白质）转移至相邻细胞。
通过细胞活力检测试剂盒（CellTiter-Blue）、流式细胞术及免疫染色分析评估外泌体介导的耐药性转变。采用蛋白质免疫印迹法检测泛素羧基末端水解酶-L1（UCH-L1）、P-糖蛋白（P-gp）、细胞外信号调节激酶1/2（ERK1/2）及磷酸化细胞外信号调节激酶1/2（p-ERK1/2）的相对蛋白水平。对93例乳腺癌样本进行免疫组化，以评估UCH-L1水平与循环外泌体中UCH-L1免疫荧光值的相关性。
阿霉素耐药的人乳腺癌细胞（MCF7/ADM）分泌携带UCH-L1和P-gp蛋白的外泌体至细胞外微环境，随后以时间依赖的方式整合至阿霉素敏感的人乳腺癌细胞（MCF7/WT）中，传递化疗耐药表型。值得注意的是，在乳腺癌患者的血液样本中，化疗前携带UCH-L1的外泌体水平与预后显著负相关。
我们的研究表明，含UCH-L1的外泌体可将化疗耐药性转移至受体细胞，且这些外泌体可用作检测乳腺癌患者化疗耐药性的非侵入性诊断生物标志物，从而实现更有效且个体化的化疗。
