The emphasis of our study was to determine the physiological function of miR‐1224‐5p in rectal cancer (RC) and its in‐depth mechanism. First, the expression of miR‐1224‐5p in RC tissues was analyzed using public data from the TCGA database. Then, miR‐1224‐5p expression in RC cell lines SW480 and SW837 was measured using the qRT‐PCR assay. The subsequent CCK‐8 assay was executed to assess the function of miR‐1224‐5p in the viability of the RC cell. Bioinformatics prediction prompted that SLC29A3 may be a potential target gene for miR‐1224‐5p. Western blotting and dual‐luciferase reporter assays were performed to affirm the above forecasting. Kaplan–Meier analysis and Cox multivariate analysis were carried out to assess the relationship between SLC29A3 and prognosis. Finally, CCK‐8, colony formation assay, and transwell assay were used for functional analysis of miR‐1224‐5p/ SLC29A3 axis in vitro. MiR‐1224‐5p was expressed at low levels in RC tissues and cell lines. Up‐regulation of miR‐1224‐5p inhibited SW480 cell viability, while inhibition of miR‐1224‐5p enhanced the viability of SW837 cells. What is more, we affirmed that miR‐1224‐5p could direct target SLC29A3, which was expressed at high levels in RC tissues. In addition, SLC29A3 could be used as an independent predictive factor of prognosis in patients with RC, and the higher SLC29A3 expression, the lower survival rate. Finally, cellular functional experiments evidenced that miR‐1224‐5p mimic can reduce the cell viability, invasion, and migration, while overexpression of SLC29A3 presented an opposite effect. Importantly, co‐transfection experiments indicated that SLC29A3 can reverse miR‐1224‐5p‐mediated inhibition in the malignant progression of RC cells. Our work raised the possibility that miR‐1224‐5p functioned as a tumor suppressor in RC, which achieved its function via targeting SLC29A3.

中文翻译：

---

MiR-1224-5p 通过靶向 SLC29A3 抑制直肠癌的恶性程度作为肿瘤抑制因子

我们研究的重点是确定 miR-1224-5p 在直肠癌 (RC) 中的生理功能及其深入机制。首先，使用来自 TCGA 数据库的公共数据分析了 RC 组织中 miR-1224-5p 的表达。然后，使用 qRT-PCR 测定法测量 RC 细胞系 SW480 和 SW837 中 miR-1224-5p 的表达。随后的 CCK-8 测定用于评估 miR-1224-5p 在 RC 细胞活力中的功能。生物信息学预测提示 SLC29A3 可能是 miR-1224-5p 的潜在靶基因。进行蛋白质印迹和双荧光素酶报告基因检测以确认上述预测。进行Kaplan-Meier分析和Cox多变量分析以评估SLC29A3与预后之间的关系。最后，CCK-8，集落形成试验，和 transwell 测定用于体外 miR-1224-5p/SLC29A3 轴的功能分析。MiR-1224-5p 在 RC 组织和细胞系中低水平表达。miR-1224-5p的上调抑制了SW480细胞的活力，而miR-1224-5p的抑制增强了SW837细胞的活力。此外，我们确认 miR-1224-5p 可以直接靶向 SLC29A3，该 SLC29A3 在 RC 组织中高水平表达。此外，SLC29A3可作为RC患者预后的独立预测因素，SLC29A3表达越高，生存率越低。最后，细胞功能实验证明 miR-1224-5p 模拟物可以降低细胞活力、侵袭和迁移，而 SLC29A3 的过表达则呈现相反的效果。重要的，共转染实验表明，SLC29A3 可以逆转 miR-1224-5p 介导的 RC 细胞恶性进展抑制作用。我们的工作提出了 miR-1224-5p 在 RC 中充当肿瘤抑制因子的可能性，其通过靶向 SLC29A3 实现其功能。