Chen Qi, Xu Rong, Zeng Chunyan, Lu Quqin, Huang Dengliang, Shi Chao, Zhang Weilong, Deng Libin, Yan Runwei, Rao Hai, Gao Guolan, Luo Shiwen
Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
Department of Biostatistics & Epidemiology, School of Public Health, Nanchang University, Nanchang, Jiangxi, China.
PLoS One. 2014 Feb 12;9(2):e88386. doi: 10.1371/journal.pone.0088386. eCollection 2014.
Recent evidence suggests that aberrant activation of Hedgehog (Hh) signaling by Gli transcription factors is characteristic of a variety of aggressive human carcinomas including ovarian cancer. Therefore, chemotherapeutic agents that inhibit activation of Gli transcription factors have emerged as promising novel therapeutic drugs for ovarian cancer.
In this study, we show that activation of Hh signaling promoted cellular migration and invasion, whereas blockade of Hh signaling with GANT61 suppressed cellular migration and invasion in ovarian cancer cells. After treatment with GANT61, cDNA microarray analyses revealed changes in many genes such as Integrin β4 subunit (ITGB4), focal adhesion kinase (FAK), etc. Furthermore, ITGB4 expression was up-regulated by Sonic Hedgehog (Shh) ligand and down-regulated by Hh signaling inhibitor. The Shh-mediated ovarian cell migration and invasion was blocked by neutralizing antibodies to ITGB4. In addition, phosphorylations of FAK were increased by Shh and decreased by Hh signaling inhibitor. Inhibition of Gli1 expression using siRNA mimicked the effects of GANT61 treatment, supporting the specificity of GANT61. Further investigations showed that activation of FAK was required for Shh-mediated cell migration and invasion. Finally, we found that down-regulation of Gli reduced the expression of ITGB4 and the phosphorylated FAK, resulting in the inhibition of tumor growth in vivo.
The Hh signaling pathway induces cell migration and invasion through ITGB4-mediated activation of FAK in ovarian cancer. Our findings suggest that the diminishment of crosstalk between phosphorylated FAK and ITGB4 due to the down-regulation of Gli family transcription factors might play a pivotal role for inhibiting ovarian cancer progression.
最近的证据表明，Gli转录因子对刺猬信号通路（Hh）的异常激活是包括卵巢癌在内的多种侵袭性人类癌症的特征。因此，抑制Gli转录因子激活的化疗药物已成为有前景的卵巢癌新型治疗药物。
在本研究中，我们发现Hh信号通路的激活促进细胞迁移和侵袭，而用GANT61阻断Hh信号通路可抑制卵巢癌细胞的迁移和侵袭。用GANT61处理后，cDNA微阵列分析揭示了许多基因的变化，如整合素β4亚基（ITGB4）、粘着斑激酶（FAK）等。此外，音猬因子（Shh）配体上调ITGB4表达，而Hh信号抑制剂下调其表达。抗ITGB4中和抗体可阻断Shh介导的卵巢细胞迁移和侵袭。此外，Shh增加FAK的磷酸化，而Hh信号抑制剂则降低其磷酸化。使用小干扰RNA（siRNA）抑制Gli1表达模拟了GANT61处理的效果，支持了GANT61的特异性。进一步研究表明，FAK的激活是Shh介导的细胞迁移和侵袭所必需的。最后，我们发现Gli的下调降低了ITGB4和磷酸化FAK的表达，从而在体内抑制肿瘤生长。
Hh信号通路通过ITGB4介导的FAK激活诱导卵巢癌细胞迁移和侵袭。我们的研究结果表明，由于Gli家族转录因子的下调，磷酸化FAK与ITGB4之间的串扰减少可能在抑制卵巢癌进展中起关键作用。
