外泌体在前列腺癌发展和转移中的作用

Role of exosomes in development and metastasis of prostate cancer

摘要:

目的 比较正常人和前列腺患者外周血外泌体的含量，并探究外泌体在前列腺癌发展和转移中的作用。方法 利用离心法收集正常人和前列腺癌患者外周血中外泌体并测定外泌体浓度。应用免疫组织化学技术检测前列腺癌组织和癌周正常组织中CD63 的表达。MTT 和Western blot 检测外泌体对前列腺癌细胞增殖活性和外泌体分泌能力的影响。复制前列腺癌肺转移小鼠模型，并检测前列腺癌患者来源的外泌体对前列腺癌细胞肺转移能力的影响。免疫荧光染色检测肺转移癌组织中CD63 和Ki-67 的表达。结果 前列腺癌患者外泌体含量（27.69±11.66）μg/ml 高于正常人（7.41±5.2）μg/ml（P <0.05）。伴远处转移的前列腺癌患者外周血中外泌体含量（33.40±10.45）μg/ml 高于无远处转移前列腺癌患者（18.17±5.96）μg/ml（P <0.05）。前列腺癌患者外周血外泌体提高前列腺癌细胞的增殖活性和外泌体产量。注射外泌体组裸鼠肺部转移灶数目（16.28±6.94）高于对照组（4.72±2.51）（t =5.265，P =0.000）。结论 外泌体提高前列腺细胞增殖活性，促进前列腺癌细胞分泌外泌体，促进前列腺癌细胞肺转移。

Abstract:

Objective To investigate the concentration of circulating exosomes in prostate cancer patients, elucidating role of exosomes in the development and metastasis of prostate cancer. Methods Circulating exosomes from human beings were isolated via centrifugation. Concentration of exosomes were determined by BCA assay. Expression of CD63 were measured by Immunohistochemistry staining. MTT assay and Western blotting were performed to identify activity of proliferation and exosomes secretion. Mouse model of lung metastasis was established to examine effect of exosomes on distant metastasis ability. Expression of CD63 and Ki-67 in pulmonary tumor tissue were determined by Immunofluorescent staining. Results The concentration of exosomes in prostate cancer patients was significantly increased compared with healthy volunteers [(27.69 ± 11.66) μg/ml vs (7.41 ± 5.2) μg/ml, P = 0.000]. Prostate cancer patients with distant metastasis experienced higher levels of exosomes when compared with patients without distant metastasis [(33.40 ± 10.45) μg/ml vs (18.17 ± 5.96) μg/ml,P < 0.05]. The Capacity of proliferation and secretion was positively associated with increase of exosomes. Number of pulmonary metastasized nodules in mice treated with exosomes were increased significantly compared with that in mice not receiving exosomes [(16.28 ± 6.94) vs (4.72 ± 2.51), P = 0.000]. Conclusion Capacity of cell proliferation,exosome secretion and tumor metastasis are positively associated with enhancement of exosomes.