Shanghai Key Laboratory of Molecular Imaging, Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences, Shanghai, 201318, People's Republic of China.
Postgraduate Training Base of Shanghai Gongli Hospital, Ningxia Medical University, Shanghai, 200135, People's Republic of China.
Cell Mol Biol Lett. 2024 Mar 27;29(1):43. doi: 10.1186/s11658-024-00549-x.
Circular RNAs (circRNAs) are single-stranded RNAs with covalently closed structures that have been implicated in cancer progression. However, the regulatory mechanisms remain largely unclear. So, the aim of this study was to reveal the role and regulatory mechanisms of circ-SLC16A1.
In this study, next-generation sequencing was used to identify abnormally expressed circRNAs between cancerous and para-carcinoma tissues. Fluorescence in situ hybridization and quantitative reverse transcription polymerase chain reaction were performed to assess the expression patterns of circ-solute carrier family 16 member 1 (SLC16A1) in non-small cell lung cancer (NSCLC) cells and tissue specimens. The dual-luciferase reporter assay was utilized to identify downstream targets of circ-SLC16A1. Transwell migration, wound healing, 5-ethynyl-2'-deoxyuridine incorporation, cell counting, and colony formation assays were conducted to assess the proliferation and migration of NSCLC cells. A mouse tumor xenograft model was employed to determine the roles of circ-SLC16A1 in NSCLC progression and metastasis in vivo.
The results found that circ-SLC16A1 was upregulated in NSCLC cells and tissues. Downregulation of circ-SLC16A1 inhibited tumor growth by reducing proliferation, lung metastasis, and lymphatic metastasis of NSCLC cells, and arrested the cell cycle in the G1 phase. Also, silencing of circ-SLC16A1 promoted apoptosis of NSCLC cells. The results of bioinformatics analysis and the dual-luciferase reporter assay confirmed that microRNA (miR)-1287-5p and profilin 2 (PFN2) are downstream targets of circ-SLC16A1. PFN2 overexpression or circ-SLC16A1 inhibition restored proliferation and migration of NSCLC cells after silencing of circ-SLC16A1. PFN2 overexpression restored migration and proliferation of NSCLC cells post miR-1287-5p overexpression.
Collectively, these findings show that miR-1287-5p/PFN2 signaling was associated with downregulation of circ-SLC16A1 and reduced invasion and proliferation of NSCLC cells. So, circ-SLC16A1 is identified as a mediator of multiple pro-oncogenic signaling pathways in NSCLC and can be targeted to suppress tumor progression.
环状 RNA（circRNAs）是具有共价闭合结构的单链 RNA，已被认为与癌症的进展有关。然而，其调控机制在很大程度上仍不清楚。因此，本研究旨在揭示 circ-SLC16A1 的作用及其调控机制。
本研究采用下一代测序技术鉴定癌组织和癌旁组织之间异常表达的 circRNAs。荧光原位杂交和实时定量逆转录聚合酶链反应检测非小细胞肺癌（NSCLC）细胞和组织标本中 circ-溶质载体家族 16 成员 1（SLC16A1）的表达模式。双荧光素酶报告基因检测鉴定 circ-SLC16A1 的下游靶基因。Transwell 迁移、划痕愈合、5-乙炔基-2'-脱氧尿苷掺入、细胞计数和集落形成实验评估 NSCLC 细胞的增殖和迁移能力。建立小鼠肿瘤移植瘤模型，体内评估 circ-SLC16A1 在 NSCLC 进展和转移中的作用。
结果发现，circ-SLC16A1 在 NSCLC 细胞和组织中上调。circ-SLC16A1 下调抑制 NSCLC 细胞的肿瘤生长，减少 NSCLC 细胞的增殖、肺转移和淋巴转移，并将细胞周期阻滞在 G1 期。此外，circ-SLC16A1 的沉默促进 NSCLC 细胞的凋亡。生物信息学分析和双荧光素酶报告基因检测结果证实，microRNA（miR）-1287-5p 和丝切蛋白 2（PFN2）是 circ-SLC16A1 的下游靶基因。沉默 circ-SLC16A1 后，PFN2 的过表达或 circ-SLC16A1 的抑制恢复了 NSCLC 细胞的增殖和迁移。miR-1287-5p 过表达后，PFN2 的过表达恢复了 NSCLC 细胞的迁移和增殖。
综上所述，这些发现表明 miR-1287-5p/PFN2 信号通路与 circ-SLC16A1 的下调以及 NSCLC 细胞侵袭和增殖的减少有关。因此，circ-SLC16A1 被确定为 NSCLC 中多种致癌信号通路的介导物，可作为抑制肿瘤进展的靶点。
