Transcriptome of ovarian cancer cells overexpressing SYNCRIP or SNU13. Transcriptome of ovarian cancer cells overexpressing SYNCRIP or SNU13

We showed that in response to chemotherapy, dying cancer cells can secrete spliceosomal components into the extracellular space. These therapy-induced secretomes enriched with spliceosomal components promote the chemoresistance of recipient tumor cells. We demonstrated that spliceosomal proteins SNU13 and SYNCRIP can relocalize from dying tumor cells to recipient tumor cells via extracellular vesicles. To investigate whether the increased abundance of splicing factors could be the reason for the acquisition of a more aggressive phenotype by tumor cells, we got SKOV3 cell lines stably overexpressing SYNCRIP or SNU13. These cell lines were more resistant to cisplatin compared to control cell line expressing empty vector. Next, to investigate how the therapy response is formed in tumor cells with and without overexpression of spliceosomal proteins SNU13 or SYNCRIP, we performed RNAseq analysis of these cells before and 24 hours after cisplatin treatment. Enrichement analyses showed that in response to cisplatin, genes associated with DNA repair and cell cycle regulation were upregulated in cancer cell lines overexpressing SYNCRIP or SNU13 compared with control cells. This study revealed previously unknown signaling molecules in the microenvironment of ovarian cancer that have potential clinical significance. Overall design: SKOV3 cell lines stably overexpressing SYNCRIP or SNU13 and control SKOV3 cell line expressing empty vector pCDH were treated or untreated with cisplatin (40 uM) for 24 hours. Then, transcriptomic profiling was performed.

本研究证实，在化疗应激下，濒死癌细胞可将剪接体（spliceosome）组分分泌至细胞外间隙。这类经治疗诱导、富含剪接体组分的分泌组，可增强受体肿瘤细胞的化疗耐药性。本研究发现，剪接体蛋白SNU13与SYNCRIP可通过细胞外囊泡，从濒死肿瘤细胞转位至受体肿瘤细胞。为探究剪接因子丰度升高是否为肿瘤细胞获得更强侵袭表型的关键诱因，本研究构建了稳定过表达SYNCRIP或SNU13的SKOV3细胞系。相较于转染空载体的对照细胞系，上述细胞系对顺铂（cisplatin）的耐药性更强。后续，为明确在过表达与未过表达剪接体蛋白SNU13或SYNCRIP的肿瘤细胞中，治疗应答的形成机制，本研究对这些细胞在顺铂处理前及处理后24小时的样本开展了RNA测序（RNA-seq）分析。富集分析结果显示，相较于对照细胞，在顺铂处理后，过表达SYNCRIP或SNU13的癌细胞系中，与DNA修复及细胞周期调控相关的基因呈上调表达。本研究揭示了卵巢癌微环境中此前未被发现的、具有潜在临床价值的信号分子。实验整体设计：将稳定过表达SYNCRIP或SNU13的SKOV3细胞系，以及转染空载体pCDH的SKOV3对照细胞系，分别用40 μM顺铂处理或不予处理，持续24小时，随后进行转录组分析（transcriptomic profiling）。