BACKGROUND Vincristine (VCR) is a chemotherapeutic drug commonly used in the treatment of Colorectal Cancer (CRC). However, VCR drug resistance may result in reduced efficacy and even failure of chemotherapy in CRC treatment. MiRNA has been demonstrated to be associated with the sensitivity of tumor cells to chemotherapy. OBJECTIVES This study aimed to identify a novel miRNA-14669 that can reverse vincristine resistance and sensitize drug-resistant colorectal cancer cells. METHODS High-throughput sequencing was performed to screen miRNAs that are associated with VCR drug resistance, and qRT-PCR was used for further validation. The miRNA mimic and inhibitor were designed and transfected into HCT-8,HCT-116 and HCT-8/VCR cells. Wound healing test examined the effect of the miRNA on the migration of colorectal cancer cells. Flow cytometry was used to evaluate cell apoptosis of HCT-8 cells. Survivin, Bcl-2, GST3, MDR1 and MRP1 expressions were detected by Western blot. RESULTS The expression of miRNA-14669 in HCT-8/VCR cells was 1.925 times higher than that of the HCT-8 cells. After transfecting with mimic miRNA, HCT-8 and HCT-116 cells showed an increased survival rate. The survival rate of HCT-8/VCR cells decreased by transfection of inhibitor. The inhibitor also sensitized HCT-8 and HCT-116 cells to VCR or 5-Fluorouracil (5-FU). The migratory ability of HCT-8 and HCT-116 cells increased by miRNA mimic while reduced by miRNA inhibitor. Overexpression of miRNA-14669 reduced apoptosis, while downregulation of miRNA- 14669 increased cell apoptosis in HCT-8 cells. The mechanism of the miRNA involved in drug resistance may be attributed to apoptosis of tumor cells, detoxification of GST3 and drug efflux induced by MDR1 and MRP1. PI3K / AKT is the signaling pathway related to drug resistance. CONCLUSION We identified a novel miRNA-14669 that may be associated with the chemotherapeutic resistance in CRC cells.

中文翻译：

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miRNA-14669 的下调通过 PI3K/AKT 信号通路逆转结直肠癌细胞中的长春新碱耐药性。

背景技术长春新碱(VCR)是一种常用于治疗结肠直肠癌(CRC)的化疗药物。然而，VCR耐药可能导致CRC治疗疗效降低甚至化疗失败。已证明 miRNA 与肿瘤细胞对化疗的敏感性有关。目的 本研究旨在鉴定一种新的 miRNA-14669，它可以逆转长春新碱耐药性并使耐药结直肠癌细胞敏感。方法采用高通量测序筛选与VCR耐药相关的miRNA，并采用qRT-PCR进一步验证。设计了miRNA模拟物和抑制剂并将其转染到HCT-8、HCT-116和HCT-8/VCR细胞中。伤口愈合测试检查了 miRNA 对结肠直肠癌细胞迁移的影响。流式细胞仪用于评估HCT-8细胞的细胞凋亡。Western blot检测Survivin、Bcl-2、GST3、MDR1和MRP1的表达。结果 miRNA-14669在HCT-8/VCR细胞中的表达是HCT-8细胞的1.925倍。转染模拟 miRNA 后，HCT-8 和 HCT-116 细胞的存活率提高。HCT-8/VCR细胞的存活率因抑制剂的转染而降低。该抑制剂还使 HCT-8 和 HCT-116 细胞对 VCR 或 5-氟尿嘧啶 (5-FU) 敏感。HCT-8 和 HCT-116 细胞的迁移能力因 miRNA 模拟而增加，而因 miRNA 抑制剂而降低。miRNA-14669 的过表达减少了细胞凋亡，而 miRNA-14669 的下调增加了 HCT-8 细胞中的细胞凋亡。miRNA参与耐药的机制可能与肿瘤细胞的凋亡有关，GST3 的解毒和 MDR1 和 MRP1 诱导的药物流出。PI3K/AKT是与耐药相关的信号通路。结论 我们鉴定了一种新的 miRNA-14669，它可能与 CRC 细胞的化疗耐药性有关。