Xiang Yongjia, Zhou Rubing, Yang Yi, Bai Hao, Liang Fan, Wang Hongmei, Wang Xia
Department of Pharmacy, Chongqing University Cancer Hospital, Chongqing, China.
J Biochem Mol Toxicol. 2025 Jan;39(1):e70089. doi: 10.1002/jbt.70089.
Although gemcitabine (GEM) is the cornerstone of the treatment of pancreatic cancer (PC), GEM resistance frequently arises. Circular RNA (circRNA) circ_0075829 is highly expressed in PC. However, whether circ_0075829 contributes to GEM resistance of PC is largely unknown. To generate GEM-resistant PC cells (BxPC-3/GR and SW1990/GR), we exposed GEM-sensitive PC cells to GEM. Circ_0075829, microRNA (miR)-326, and glutamic-oxaloacetic transaminase 1 (GOT1) were quantified by a qRT-PCR or western blot method. Cell survival and viability were gauged by MTS assay. Cell proliferation, apoptosis, invasion, and migration were assessed by EdU, flow cytometry, transwell, and wound-healing assays, respectively. Dual-luciferase reporter assays were used to verify the relationship between miR-326 and circ_0075829 or GOT1. Mouse xenografts were performed to evaluate the role of circ_0075829 in vivo. Our data showed that circ_0075829 was upregulated in GEM-resistant PC tissues and cells. Knockdown of circ_0075829 impeded the proliferation, invasion, migration, and glutamine metabolism, and promoted cell apoptosis and GEM sensitivity of GEM-resistant PC cells. Moreover, circ_0075829 silencing suppressed the tumorigenicity of SW1990/GR cells and sensitized them to the cytotoxic effect of GME in vivo. Mechanistically, circ_0075829 bound miR-326 and exerted regulatory effects by affecting miR-326 expression. GOT1 was a direct miR-326 target and a key downstream effector of miR-326. Furthermore, circ_0075829 modulated GOT1 expression via miR-326. Our findings establish a novel regulatory network, the circ_0075829/miR-326/GOT1 competing endogenous RNA (ceRNA) crosstalk, in the regulation of GEM resistance in PC.
尽管吉西他滨（GEM）是胰腺癌（PC）治疗的基石，但吉西他滨耐药经常出现。环状RNA（circRNA）circ_0075829在PC中高表达。然而，circ_0075829是否导致PC的吉西他滨耐药在很大程度上尚不清楚。为了生成吉西他滨耐药的PC细胞（BxPC-3/GR和SW1990/GR），我们将吉西他滨敏感的PC细胞暴露于吉西他滨。通过qRT-PCR或蛋白质印迹法对circ_0075829、微小RNA（miR）-326和谷草转氨酶1（GOT1）进行定量。通过MTS测定法评估细胞存活和活力。分别通过EdU、流式细胞术、Transwell和伤口愈合测定法评估细胞增殖、凋亡、侵袭和迁移。使用双荧光素酶报告基因测定法验证miR-326与circ_0075829或GOT1之间的关系。进行小鼠异种移植以评估circ_0075829在体内的作用。我们的数据表明，circ_0075829在吉西他滨耐药的PC组织和细胞中上调。敲低circ_0075829可抑制吉西他滨耐药的PC细胞的增殖、侵袭、迁移和谷氨酰胺代谢，并促进细胞凋亡和吉西他滨敏感性。此外，circ_0075829沉默抑制了SW1990/GR细胞的致瘤性，并使其在体内对GME的细胞毒性作用敏感。机制上，circ_0075829与miR-326结合并通过影响miR-326表达发挥调节作用。GOT1是miR-326的直接靶标和miR-326的关键下游效应物。此外，circ_0075829通过miR-326调节GOT1表达。我们的研究结果在PC的吉西他滨耐药调节中建立了一个新的调控网络，即circ_0075829/miR-326/GOT1竞争性内源RNA（ceRNA）串扰。
