Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
Int J Oncol. 2012 Jun;40(6):2038-48. doi: 10.3892/ijo.2012.1395. Epub 2012 Mar 7.
Krüppel-like factor 4 (KLF4) is a zinc-finger protein that plays an important role in the progression of gastric carcinoma. The abnormal activation of β-catenin frequently occurs in gastric cancer and has been associated with the promotion of tumor growth, invasion and metastasis. However, the potential interaction between KLF4 and β-catenin during gastric cancer development is unknown. In this study, a lentiviral KLF4 expression vector was constructed and utilized to transfect the human gastric cancer cell lines, SGC-7901, BGC-823, MKN-28 and MKN-45. KLF4 and β-catenin expression levels were measured by quantitative real-time RT-PCR and western blot analysis. Cell proliferation, colony formation and invasive potential were determined in the KLF4-transfected gastric cancer cells. The expression of E-cadherin and matrix metallopeptidase 2 (MMP2) was determined by western blot analysis. The overexpression of KLF4 significantly inhibited the expression of β-catenin in the MKN-45 gastric cancer cells. The restored expression of KLF4 suppressed proliferation, colony formation and inhibited the invasion and metastatic properties of MKN-45 gastric cancer cells. Furthermore, the forced expression of KLF4 in gastric tumor cell lines restored E-cadherin expression and inhibited MMP2 expression. Consistent with the in vitro findings, the enforced expression of the KLF4 gene in MKN-45 gastric carcinoma cells by lentiviral vector-mediated gene transfer effectively suppressed tumor growth in vivo. Our results show that KLF4 inhibits β-catenin expression and regulates the β-catenin-mediated biological behaviors of gastric cancer cells. The modulation of KLF4 expression may represent a novel therapeutic approach for β-catenin-driven malignancies.
Krüppel 样因子 4（KLF4）是一种锌指蛋白，在胃癌的进展中发挥着重要作用。β-连环蛋白的异常激活经常发生在胃癌中，并与促进肿瘤生长、侵袭和转移有关。然而，KLF4 和 β-连环蛋白在胃癌发展过程中的潜在相互作用尚不清楚。在这项研究中，构建了慢病毒 KLF4 表达载体，并用于转染人胃癌细胞系 SGC-7901、BGC-823、MKN-28 和 MKN-45。通过实时定量 RT-PCR 和 Western blot 分析测量 KLF4 和 β-连环蛋白的表达水平。在 KLF4 转染的胃癌细胞中测定细胞增殖、集落形成和侵袭潜能。通过 Western blot 分析测定 E-钙黏蛋白和基质金属蛋白酶 2（MMP2）的表达。KLF4 的过表达显著抑制了 MKN-45 胃癌细胞中 β-连环蛋白的表达。KLF4 的恢复表达抑制了 MKN-45 胃癌细胞的增殖、集落形成，并抑制了其侵袭和转移特性。此外，在胃癌肿瘤细胞系中强制表达 KLF4 恢复了 E-钙黏蛋白的表达并抑制了 MMP2 的表达。与体外研究结果一致，慢病毒载体介导的基因转移强制表达 KLF4 基因有效抑制了体内 MKN-45 胃癌细胞的肿瘤生长。我们的研究结果表明，KLF4 抑制 β-连环蛋白的表达并调节 β-连环蛋白介导的胃癌细胞的生物学行为。调节 KLF4 的表达可能代表了针对β-连环蛋白驱动的恶性肿瘤的一种新的治疗方法。
