尽管第2型糖尿病（T2D）与结直肠癌发生风险的关系在临床研究中被广泛定义，但T2D诱导结直肠癌的治疗方法和分子机制以及高血糖如何影响其进展仍然未知。在这里，我们研究了乳铁蛋白（LF）在抑制T2D小鼠结肠癌进展中的作用，并揭示了相关的分子机制，包括DNA 5mC和RNA m6A水平。我们检查了LF（50％铁饱和度）对高浓度葡萄糖下结肠肿瘤细胞的迁移和侵袭的影响。然后，共同分析结肠肿瘤细胞的转录组和DNA甲基化谱图，筛选出特定基因（NT5DC3），并通过q-PCR和Western blot检测了NT5DC3在75个临床血液样品中的表达水平，以研究NT5DC3是否是区分T2D患者和T2D诱导结肠癌患者与健康志愿者的生物标志物。此外，在T2D小鼠移植结肠肿瘤模型中，研究了LF和NT5DC3蛋白对结肠肿瘤的抑制作用。此外，测量了由LF调节的NT5DC3的5mC / m6A修饰位点的表观遗传学改变。利用八种m6A相关基因的siRNA片段，证明了调节NT5DC m6A的特定基因（WTAP），最后评估了LF对WTAP / NT5DC3 / HKDC1轴的影响。共同分析转录组和DNA甲基化谱图筛选出了特定基因NT5DC3，而HKDC1可能是NT5DC3的下游传感器。从机理上讲，LF依赖的细胞DNA 5mC和RNA m6A表观重构调节NT5DC3的表达水平。 WTAP在调节NT5DC3 m6A修饰方面发挥关键作用，并随后控制NT5DC3下游靶点HKDC1的表达。此外，共同治疗乳铁蛋白和NT5DC3蛋白通过改变异常的表观遗传标记抑制结肠癌的生长。令人惊讶的是，临床血液样品分析表明，NT5DC3蛋白表达是区分T2D或T2D诱导结肠癌与健康人的必要条件。综上所述，本研究揭示了乳铁蛋白在高血糖状态下抑制结肠癌进展的重要因素，从而显著扩大了自然饮食介导的肿瘤抑制范围。©2023. 作者。

Although the relationship between type 2 diabetes (T2D) and the increased risk of colorectal carcinogenesis is widely defined in clinical studies, the therapeutic methods and molecular mechanism of T2D-induced colon cancer and how does hyperglycemia affect the progression is still unknown. Here, we studied the function of lactoferrin (LF) in suppressing the progression of colon cancer in T2D mice, and uncovered the related molecular mechanisms in DNA 5mC and RNA m6A levels.We examined the effects of LF (50% iron saturation) on the migration and invasion of colon tumor cells under high concentration of glucose. Then, transcriptomics and DNA methylation profilings of colon tumor cells was co-analyzed to screen out the special gene (NT5DC3), and the expression level of NT5DC3 in 75 clinical blood samples was detected by q-PCR and western blot, to investigate whether NT5DC3 was a biomarker to distinguish T2D patients and T2D-induced colon cancer patients from healthy volunteers. Futhermore, in T2D mouse with xenografted colon tumor models, the inhibitory effects of LF and NT5DC3 protein on colon tumors were investigated. In addition, epigenetic alterations were measured to examine the 5mC/m6A modification sites of NT5DC3 regulated by LF. Utilizing siRNA fragments of eight m6A-related genes, the special gene (WTAP) regulating m6A of NT5DC was proved, and the effect of LF on WTAP/NT5DC3/HKDC1 axis was finally evaluated.A special gene NT5DC3 was screened out through co-analysis of transcriptomics and DNA methylation profiling, and HKDC1 might be a downstream sensor of NT5DC3. Mechanistically, LF-dependent cellular DNA 5mC and RNA m6A profiling remodeling transcriptionally regulate NT5DC3 expression. WTAP plays a key role in regulating NT5DC3 m6A modification and subsequently controls NT5DC3 downstream target HKDC1 expression. Moreover, co-treatment of lactoferrin and NT5DC3 protein restrains the growth of colon tumors by altering the aberrant epigenetic markers. Strikingly, clinical blood samples analysis demonstrates NT5DC3 protein expression is required to direct the distinction of T2D or T2D-induced colon cancer with healthy humans.Together, this study reveals that lactoferrin acts as a major factor to repress the progression of colon cancer under hyperglycemia, thus, significantly expanding the landscape of natural dietary mediated tumor suppression.© 2023. The Author(s).