生物活性肽通过HMGA2调节Wnt通路抑制结直肠癌细胞增殖

Colorectal cancer is a common malignant tumor in the gastrointestinal tract. Surgery combined with radiotherapy and chemotherapy can improve the 5-year survival rate of patients, but affect the overall quality of life. Here, a low molecular active peptide was isolated and extracted from organs of sheep by immune induction. In the previous study, it has been found that this active peptide can inhibit the proliferation of tumor cells, induce apoptosis, reduce the toxicity and increase the sensitivity of chemotherapeutic drugs, and improve the quality of life of tumor-bearing mice, So, we named it anticancer active peptide (ACBP). In order to further reveal the molecular mechanism of the anticancer effect of ACBP, HCT116 was treated with ACBP, which found that there were significant differences in gene expression between HMGA2 and Wnt-signaling pathway after transcriptome sequencing analysis. On this basis, we hypothesized that HMGA2 regulated Wnt-signaling pathway to inhibit colon cancer. We intend to explore the role of HMGA2 in colon cancer at the tissue, cell and animal levels, and then reveal whether it plays a role by regulating the Wnt-signaling pathway. We will also provide whether ACBP plays an anti-tumor role by targeting HMGA2. The purpose of this study is to elucidate the function and molecular mechanism of ACBP regulating colorectal cancer cells, which is of great significance to explores the pathogenesis of colorectal cancer and its prevention and treatment.

结直肠癌是胃肠道常见的恶性肿瘤，手术联合放化疗可改善患者的五年存活率，却影响患者整体的生存质量。本课题组通过对羊免疫诱导后从脏器中分离提取得到一种低分子活性多肽，既往发现其具有抑制肿瘤细胞增殖、诱导细胞凋亡，并具有化疗药物减毒增敏作用，能提高荷瘤小鼠的生存质量，我们将其命名为抗癌活性肽(ACBP)。为进一步揭示ACBP抗癌作用的分子机制，在HCT116经ACBP处理后，我们进行了转录组测序分析，发现HMGA2及Wnt通路的基因表达有显著差异。据此提出假设：ACBP通过HMGA2调控Wnt通路抑制结直肠癌。我们拟在组织、细胞和动物水平探讨HMGA2在结直肠癌中的作用，进而揭示其是否通过调控Wnt通路发挥作用。我们还将揭示ACBP是否通过靶向作用HMGA2发挥抗肿瘤作用。通过本研究将阐明ACBP调控结直肠癌细胞的功能和分子机制，对于探讨结直肠癌的发生机制及防治均具有重要意义。

抗癌生物活性肽(ACBP)是本实验室从肿瘤提取物免疫山羊脾脏中分离到的一种新的生物活性肽，在体外和体内均能抑制结直肠癌的增殖。然而，ACBP在分子水平上是如何抑制结直肠癌增殖尚不清楚。因此，我们进行了本项目的研究：通过药物转录组学和qRT-PCR分析，ACBP在结直肠癌细胞中显著抑制Wnt/β-catenin相关基因(cyclin D1, met和c-myc)的表达。Wnt通路中的关键蛋白活性β-catenin在HCT116、RKO和HT29三个结直肠癌细胞系中被ACBP显著降低。因此，活性β-catenin的核积累被阻滞，最终导致癌基因cyclin D1、met和cmyc的表达降低。此外，我们还证实了β-catenin活性降低是由于ACBP抑制磷酸化LRP6和促进磷酸化β-catenin的表达。在结肠癌类器官组织上的研究结果表明，ACBP能够抑制结直肠癌类器官的生长。免疫组化结果表明ACBP处理后，结直肠癌类器官中Ki-67、Cyclin-D1、active-β-catenin、Met、N-P-β-catenin表达均减弱。因此，我们的研究结果表明，ACBP可以靶向Wnt/β-catenin通路，特别是活性β-catenin，并呈剂量依赖性抑制结直肠癌细胞的增殖、迁移以及侵袭，是一种很有前景的结直肠癌抗癌药物。