Department of Medical Biology and Genetics, Faculty of Medicine, 37740Charles University, Hradec Kralove, Czech Republic.
Department of Chemistry, Faculty of Sciences, 48282University of Hradec Kralove, Hradec Kralove, Czech Republic.
Hum Exp Toxicol. 2021 Dec;40(12):2063-2073. doi: 10.1177/09603271211021479. Epub 2021 Jun 2.
Colorectal carcinoma (CRC) is a leading malignant disease in most developed countries. In advanced stages it presents with metastatic dissemination and significant chemoresistance. Despite intensive studies, no convincing evidence has been published concerning the association of cadherins and epithelial-mesenchymal transition (EMT) as a direct cause of acquired chemoresistance in CRC. The present study was designed to investigate the role of E-cadherin in EMT and its associated chemosensitivity/chemoresistance in four immortalized CRC cell lines representing various stages of CRC development (i.e. HT29 and Caco-2-early, SW480 and SW620 late). The expression of E-cadherin gene CDH1 was downregulated by the specific siRNA. Cell proliferation and chemosensitivity to irinotecan (IT) and oxaliplatin (OPT) were detected using WST-1 and x-CELLigence Real Time analysis. Expression of selected EMT markers were tested and compared using RT-PCR and western blot analysis in both variants (E-cadherin silenced and non-silenced) of each cell line. We have discovered that downregulation of E-cadherin expression has a diverse effect on both cell proliferation as well as the expression of EMT markers in individual tested CRC cell lines, with Caco-2 cells being the most responsive. On the other hand, reduced E-cadherin expression resulted in increased sensitivity of all cell lines to IT and mostly to OPT which might be related to changes in intracellular metabolism of these drugs. These results suggest dichotomy of E-cadherin involvement in the phenotypic EMT spectrum of CRC and warrants further mechanistic studies.
结直肠癌（CRC）是大多数发达国家主要的恶性疾病。在晚期，它表现出转移性扩散和明显的化疗耐药性。尽管进行了深入的研究，但关于钙黏蛋白和上皮-间充质转化（EMT）作为 CRC 获得性化疗耐药的直接原因的关联，尚未发表令人信服的证据。本研究旨在调查 E-钙黏蛋白在 EMT 中的作用及其在四个代表 CRC 发展不同阶段的永生化 CRC 细胞系中的相关化疗敏感性/化疗耐药性（即 HT29 和 Caco-2-早期、SW480 和 SW620-晚期）。通过特异性 siRNA 下调 E-钙黏蛋白基因 CDH1 的表达。使用 WST-1 和 x-CELLigence 实时分析检测细胞增殖和对伊立替康（IT）和奥沙利铂（OPT）的化疗敏感性。使用 RT-PCR 和 Western blot 分析在每个细胞系的两种变体（E-钙黏蛋白沉默和非沉默）中检测并比较选定的 EMT 标记物的表达。我们发现，下调 E-钙黏蛋白表达对个体测试的 CRC 细胞系中的细胞增殖和 EMT 标记物的表达有不同的影响，其中 Caco-2 细胞反应最为敏感。另一方面，E-钙黏蛋白表达的降低导致所有细胞系对 IT 的敏感性增加，对 OPT 的敏感性增加，这可能与这些药物的细胞内代谢变化有关。这些结果表明 E-钙黏蛋白在 CRC 的表型 EMT 谱中的参与存在二分法，需要进一步的机制研究。
