Yang Xiaohui, Wang Shuai, Yu Weihua, Zheng Yixiong, Wu Yulian
Department of General Surgery, The Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, China.
Medicine (Baltimore). 2020 Jul 2;99(27):e20944. doi: 10.1097/MD.0000000000020944.
Colorectal cancer is the second commonly seen cancer around the world and accounts for 13% of all human cancers. Among them, 25% of all case were diagnosed with metastasis and 50% occurs metastasis during the development of disease. Cetuximab is a chimeric monoclonal antibody against epidermal growth factor receptor, and is used for treatment of metastatic colorectal cancer alone or combined with chemotherapy or radiation therapy. Integrin-beta 1 (ITGB1), which is also known as CD29, and plays an important role in development of malignant cancers. However, the effect of ITGB1 in promoting the anti-tumor effect of cetuximab is not fully understand.
The model of ITGB1 inhibition and overexpression was firstly constructed in LS174T cells, and the viability of cells in each group was detected using CCK-8 assay. The expression of key factors in tumor formation process at transcription level was detected using real-time quantitative polymerase chain reaction method. The expression of key proteins in metastasis process, cell apoptosis and activation of Ras/Raf/MEK signaling pathway was detected using western blotting analysis. And the concentration of key factors of in tumor formation process in cultured medium of LS174T cells were detected using enzyme-linked immunosorbent assay method.
We found that cetuximab could inhibit the proliferation of LS174T cells, and inhibition of ITGB1 enhanced this effect while overexpression of ITGB1 reduced this effect. We further found that cetuximab could inhibit the expression and secretion of extracellular matrix degradation related molecules in cultured medium and transcription level. Besides, we also found that the expression of key factors in angiogenesis and extracellular matrix degradation related proteins were also reduced after cetuximab treatment. These effects might be mediated by Ras/Raf/MAPK signaling pathway and enhanced after inhibition of ITGB1 expression.
Inhibition of ITGB1 might be a new therapeutic method in colorectal cancer.
结直肠癌是全球第二常见的癌症，占所有人类癌症的13%。其中，25%的病例在确诊时已发生转移，50%在疾病发展过程中发生转移。西妥昔单抗是一种抗表皮生长因子受体的嵌合单克隆抗体，可单独或与化疗或放疗联合用于治疗转移性结直肠癌。整合素β1（ITGB1），也称为CD29，在恶性肿瘤的发展中起重要作用。然而，ITGB1在增强西妥昔单抗抗肿瘤作用方面的效果尚未完全明确。
首先在LS174T细胞中构建ITGB1抑制和过表达模型，使用CCK-8法检测各组细胞的活力。采用实时定量聚合酶链反应法检测肿瘤形成过程中关键因子在转录水平的表达。采用蛋白质免疫印迹分析检测转移过程、细胞凋亡及Ras/Raf/MEK信号通路激活过程中关键蛋白的表达。采用酶联免疫吸附测定法检测LS174T细胞培养基中肿瘤形成过程关键因子的浓度。
我们发现西妥昔单抗可抑制LS174T细胞的增殖，抑制ITGB1可增强此作用，而ITGB1过表达则降低此作用。我们进一步发现，西妥昔单抗可抑制培养基中细胞外基质降解相关分子在转录水平的表达和分泌。此外，我们还发现西妥昔单抗治疗后，血管生成和细胞外基质降解相关蛋白中关键因子的表达也降低。这些作用可能由Ras/Raf/MAPK信号通路介导，抑制ITGB1表达后增强。
抑制ITGB1可能是结直肠癌的一种新治疗方法。
