Pancreatic cancer is one of the most malignant tumors. However, radiotherapy can lead to tumor recurrence, which is caused by the residual surviving cells repopulation stimulated by some molecular released from dying cells. Exosomes may mediate cell-cell communication and transfer kinds of signals from the dying cells to the surviving cells for stimulating tumor repopulation. Circular RNAs (circRNAs) may be one vital kind of exosomal cargos involving in modulating cancer cell repopulation. Next generation sequencing (NGS) and bioinformatics were performed to analyze and annotate the expression and function of exosome-derived circRNAs in pancreatic cancer cells after radiation. Four circRNAs were chosen for qRT-PCR analysis to validate the sequencing results. In this study, 3580 circRNAs were annotated in literatures and circBase among 12,572 identified circRNAs. There were 196 filtered differentially expressed circRNAs (the up-regulation and down-regulation respectively is 182 and 14, fold change > 2, p-value < 0.05). Regulation of metabolic process and lysine degradation were the main enriched biological processes and pathway according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The hsa_circ_0002130-hsa_miR_4482-3p-NBN interaction network suggested potential sponging miRNA and target mRNA. Our results provided potential functions of circRNAs to explore molecular mechanisms and therapeutic targets in pancreatic cancer cell repopulation upon irradiation.

中文翻译：

---

胰腺癌细胞增殖过程中照射后外泌体 circRNA 的分析。

胰腺癌是最常见的恶性肿瘤之一。然而，放疗可能导致肿瘤复发，这是由于垂死细胞释放的一些分子刺激残留的存活细胞重新增殖而引起的。外泌体可以介导细胞间通讯，并将各种信号从死亡细胞转移到存活细胞，以刺激肿瘤重新增殖。环状RNA（circRNA）可能是参与调节癌细胞增殖的一种重要的外泌体货物。采用下一代测序（NGS）和生物信息学来分析和注释放疗后胰腺癌细胞中外泌体衍生的 circRNA 的表达和功能。选择四种 circRNA 进行 qRT-PCR 分析以验证测序结果。在这项研究中，在 12,572 个已识别的 circRNA 中，有 3580 个 circRNA 在文献和 circBase 中进行了注释。筛选出差异表达的circRNA 196个（上调和下调分别为182和14，倍数变化> 2，p值< 0.05）。根据基因本体论（GO）和京都基因与基因组百科全书（KEGG）分析，代谢过程的调节和赖氨酸降解是主要富集的生物过程和途径。hsa_circ_0002130-hsa_miR_4482-3p-NBN 相互作用网络表明潜在的海绵 miRNA 和目标 mRNA。我们的结果提供了 circRNA 的潜在功能，以探索放射后胰腺癌细胞增殖的分子机制和治疗靶点。