Munagala Radha, Aqil Farrukh, Gupta Ramesh C
Department of Medicine, University of Louisville, 580 S. Preston Street, Louisville, KY, 40202, USA.
James Graham Brown Cancer Center, University of Louisville, 580 S. Preston Street, Louisville, KY, 40202, USA.
Tumour Biol. 2016 Aug;37(8):10703-14. doi: 10.1007/s13277-016-4939-8. Epub 2016 Feb 11.
Prognosis of lung cancer still remains grim largely due to recurrence and aggressive metastasis of the disease. In this study, we examined the potential of exosomal miRNAs as biomarkers of recurrent lung cancer. Initially, in vitro miRNA profiles of normal lung (Beas-2b) and lung cancer (H1299) cells and of exosomes isolated from conditioned media were determined. In vivo study involved establishing subcutaneous primary and recurrent lung cancer xenografts in nude mouse model and examining tumor and serum exosomal miRNA alteration in secondary/recurrent lung tumors. A total of 77 miRNAs were observed to be significantly modulated in the H1299 cells (47 miRNA upregulated and 30 downregulated) compared to the Beas-2b cells. The exosomes isolated from conditioned media indicated several miRNAs which were in agreement with cells of origin. A similarity was also observed between miRNAs from serum exosomes and tumors, indicating their origin from the lung tumors. Two miRNAs, miR-21 and miR-155, were found to be significantly upregulated in recurrent tumors compared to primary tumors. These miRNAs were also upregulated in serum exosomes of recurrent tumor-bearing animals versus non-tumor- or primary tumor-bearing animals. Increased expression of the recurrent disease markers were also observed in recurrent tumors compared with primary tumors. Serum exosomes from recurrent tumor mice mirrored its tumor profile in expressing higher levels of these proteins compared with exosomes from primary tumor mice. Our data suggest that exosomal miRNA signatures may be a true representation of a pathological profile of lung cancer; thus, miRNAs could serve as promising biomarkers for non-invasive diagnosis of the disease.
肺癌的预后仍然很严峻，这主要是由于该疾病的复发和侵袭性转移。在本研究中，我们检测了外泌体miRNA作为复发性肺癌生物标志物的潜力。首先，测定了正常肺（Beas-2b）和肺癌（H1299）细胞以及从条件培养基中分离的外泌体的体外miRNA谱。体内研究包括在裸鼠模型中建立皮下原发性和复发性肺癌异种移植瘤，并检测继发性/复发性肺肿瘤中肿瘤和血清外泌体miRNA的变化。与Beas-2b细胞相比，共观察到77种miRNA在H1299细胞中受到显著调节（47种miRNA上调，30种下调）。从条件培养基中分离的外泌体显示出几种与来源细胞一致的miRNA。血清外泌体和肿瘤中的miRNA之间也观察到相似性，表明它们来源于肺肿瘤。与原发性肿瘤相比，发现两种miRNA，即miR-21和miR-155，在复发性肿瘤中显著上调。与未患肿瘤或原发性肿瘤的动物相比，这些miRNA在携带复发性肿瘤的动物的血清外泌体中也上调。与原发性肿瘤相比，复发性肿瘤中还观察到复发性疾病标志物的表达增加。与原发性肿瘤小鼠的外泌体相比，复发性肿瘤小鼠的血清外泌体在表达这些蛋白质的水平上反映了其肿瘤特征。我们的数据表明，外泌体miRNA特征可能是肺癌病理特征的真实体现；因此，miRNA可作为该疾病非侵入性诊断的有前景的生物标志物。
