Bhat Anjali, Yadav Joni, Thakur Kulbhushan, Aggarwal Nikita, Chhokar Arun, Tripathi Tanya, Singh Tejveer, Jadli Mohit, Veerapandian Veeramohan, Bharti Alok Chandra
Molecular Oncology Laboratory, Department of Zoology, University of Delhi (North Campus), Delhi, 110007, India.
Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
BMC Cancer. 2022 Feb 11;22(1):164. doi: 10.1186/s12885-022-09262-4.
Exosomes play a key role in cell-to-cell communication and are integral component of the tumor microenvironment. Recent observations suggest transfer of RNA through tumor-derived exosomes that can potentially translate into regulatory proteins in the recipient cells. Role of cervical cancer-derived exosomes and their transcript cargo is poorly understood.
The total RNA of exosomes from HPV-positive (SiHa and HeLa) and HPV-negative (C33a) cervical cancer cell lines were extracted and the transcripts were estimated using Illumina HiSeq X. Further, validation of HPV transcripts were performed using RT-PCR.
3099 transcripts were found to be differentially-exported in HPV-positive vs. HPV-negative exosomes (p value <0.05). Analysis of top 10 GO terms and KEGG pathways showed enrichment of transcripts belonging to axon guidance and tumor innervation in HPV-positive exosomes. Among top 20 overexpressed transcripts, EVC2, LUZP1 and ANKS1B were the most notable due to their involvement in Hh signaling, cellular migration and invasion, respectively. Further, low levels of HPV-specific reads were detected. RT-PCR validation revealed presence of E6I splice variant of HPV18 in exosomal RNA of HeLa cells. The E6I transcripts were consistently retained in exosomes obtained from HeLa cells undergoing 5-FU and cisplatin-induced oxidative stress.
Our data suggests the enrichment of poly-A RNA transcripts in the exosomal cargo of cervical cancer cells, which includes pro-tumorigenic cellular RNA and viral transcripts such as HPV E6, which may have clinical utility as potential exosomal biomarkers of cervical cancer.
外泌体在细胞间通讯中起关键作用，是肿瘤微环境的重要组成部分。最近的观察结果表明，RNA可通过肿瘤来源的外泌体进行转移，这些RNA有可能在受体细胞中翻译为调节蛋白。人们对宫颈癌来源的外泌体及其转录物的作用了解甚少。
提取HPV阳性（SiHa和HeLa）和HPV阴性（C33a）宫颈癌细胞系外泌体的总RNA，并使用Illumina HiSeq X对转录物进行评估。此外，使用RT-PCR对HPV转录物进行验证。
发现3099个转录物在HPV阳性与HPV阴性外泌体中差异输出（p值<0.05）。对前10个GO术语和KEGG通路的分析表明，HPV阳性外泌体中属于轴突导向和肿瘤神经支配的转录物富集。在20个过表达转录物中，EVC2、LUZP1和ANKS1B最为显著，因为它们分别参与Hh信号传导、细胞迁移和侵袭。此外，检测到低水平的HPV特异性读数。RT-PCR验证显示HeLa细胞外泌体RNA中存在HPV18的E6I剪接变体。E6I转录物始终保留在经历5-氟尿嘧啶和顺铂诱导的氧化应激的HeLa细胞获得的外泌体中。
我们的数据表明，宫颈癌细胞外泌体货物中富含多聚腺苷酸RNA转录物，其中包括促肿瘤细胞RNA和病毒转录物，如HPV E6，它们可能作为宫颈癌潜在的外泌体生物标志物具有临床应用价值。
