Although gemcitabine has been considered as the first-line drug for advanced pancreatic cancer (PC), development of resistance to gemcitabine severely limits the effectiveness of this chemotherapy, and the underlying mechanism of gemcitabine resistance remains unclear. Various factors, such as ATP binding cassette (ABC) transporters, microRNAs and their downstream signaling pathways are included in chemoresistance to gemcitabine. This study investigated the potential mechanisms of microRNAs and ABC transporters related signaling pathways for PC resistance to gemcitabine both in vivo and in vitro. Immunohistochemistry and Western blotting were applied to detect the expression of ABC transporters. Molecular docking analysis was performed to explore whether gemcitabine interacted with ABC transporters. Gain-of-function and loss-of-function analyses were performed to investigate the functions of hsa-miR-3178 in vitro and in vivo. Bioinformatics analysis, Western blotting and dual-luciferase reporter assay were used to confirm the downstream regulatory mechanisms of hsa-miR-3178. We found that P-gp, BCRP and MRP1 were highly expressed in gemcitabine-resistant PC tissues and cells. Molecular docking analysis revealed that gemcitabine can bind to the ABC transporters. Hsa-miR-3178 was upregulated in gemcitabine resistance PANC-1 cells as compared to its parental PANC-1 cells. Moreover, we found that hsa-miR-3178 promoted gemcitabine resistance in PC cells. These results were also verified by animal experiments. RhoB was down-regulated in gemcitabine-resistant PC cells and it was a downstream target of hsa-miR-3178. Kaplan–Meier survival curve showed that lower RhoB expression was significantly associated with poor overall survival in PC patients. Rescue assays demonstrated that RhoB could reverse hsa-miR-3178-mediated gemcitabine resistance. Interestingly, hsa-miR-3178 promoted gemcitabine resistance in PC by activating the PI3K/Akt pathway-mediated upregulation of ABC transporters. Our results indicate that hsa-miR-3178 promotes gemcitabine resistance via RhoB/PI3K/Akt signaling pathway-mediated upregulation of ABC transporters. These findings suggest that hsa-miR-3178 could be a novel therapeutic target for overcoming gemcitabine resistance in PC.

中文翻译：

---

Hsa-miR-3178/RhoB/PI3K/Akt，一种新的信号通路调节 ABC 转运蛋白以逆转胰腺癌的吉西他滨耐药性

尽管吉西他滨被认为是晚期胰腺癌（PC）的一线药物，但对吉西他滨的耐药性严重限制了这种化疗的有效性，吉西他滨耐药的潜在机制仍不清楚。各种因素，如 ATP 结合盒 (ABC) 转运蛋白、microRNA 及其下游信号通路都包括在对吉西他滨的化学抗性中。本研究调查了体内和体外 PC 对吉西他滨耐药的 microRNA 和 ABC 转运蛋白相关信号通路的潜在机制。应用免疫组织化学和蛋白质印迹法检测ABC转运蛋白的表达。进行分子对接分析以探索吉西他滨是否与 ABC 转运蛋白相互作用。进行功能获得和功能丧失分析以研究 hsa-miR-3178 在体外和体内的功能。生物信息学分析、蛋白质印迹和双荧光素酶报告基因分析用于确认 hsa-miR-3178 的下游调控机制。我们发现 P-gp、BCRP 和 MRP1 在吉西他滨耐药的 PC 组织和细胞中高度表达。分子对接分析表明，吉西他滨可以与 ABC 转运蛋白结合。与其亲本PANC-1细胞相比，Hsa-miR-3178在吉西他滨耐药PANC-1细胞中上调。此外，我们发现 hsa-miR-3178 促进了 PC 细胞对吉西他滨的耐药性。这些结果也得到了动物实验的验证。RhoB 在吉西他滨耐药的 PC 细胞中被下调，它是 hsa-miR-3178 的下游靶标。Kaplan-Meier 生存曲线显示，较低的 RhoB 表达与 PC 患者较差的总体生存率显着相关。救援分析表明，RhoB 可以逆转 hsa-miR-3178 介导的吉西他滨耐药性。有趣的是，hsa-miR-3178 通过激活 PI3K/Akt 通路介导的 ABC 转运蛋白上调来促进 PC 中的吉西他滨耐药性。我们的结果表明，hsa-miR-3178 通过 RhoB/PI3K/Akt 信号通路介导的 ABC 转运蛋白上调促进吉西他滨耐药。这些发现表明，hsa-miR-3178 可能是克服 PC 中吉西他滨耐药性的新治疗靶点。hsa-miR-3178 通过激活 PI3K/Akt 通路介导的 ABC 转运蛋白上调来促进 PC 中的吉西他滨耐药性。我们的结果表明，hsa-miR-3178 通过 RhoB/PI3K/Akt 信号通路介导的 ABC 转运蛋白上调促进吉西他滨耐药。这些发现表明，hsa-miR-3178 可能是克服 PC 中吉西他滨耐药性的新治疗靶点。hsa-miR-3178 通过激活 PI3K/Akt 通路介导的 ABC 转运蛋白上调来促进 PC 中的吉西他滨耐药性。我们的结果表明，hsa-miR-3178 通过 RhoB/PI3K/Akt 信号通路介导的 ABC 转运蛋白上调促进吉西他滨耐药。这些发现表明，hsa-miR-3178 可能是克服 PC 中吉西他滨耐药性的新治疗靶点。