Liu Tingting, Zhang Junzhong, Chai Zhongqiu, Wang Gang, Cui Naiqiang, Zhou Bing
Department of Integrated Chinese and Western Medicine Surgery, Tianjin University of Traditional Chinese Medicine, Tianjin, China.
Department of Anorectal Surgery, Tianjin Binhai New Area Traditional Chinese Medicine Hospital, Tianjin, China.
Oncotarget. 2017 Sep 27;8(53):91614-91627. doi: 10.18632/oncotarget.21345. eCollection 2017 Oct 31.
EGb 761, the standard ginkgo biloba extract, is frequently prescribed in traditional Chinese medicine. Currently, there is no research focusing on its role in human colorectal cancer progression. In our study, we determined the anti-metastatic effect of EGb 761 on colorectal cancer cells and further explored the potential underlying regulatory mechanism. The cell migration and invasion assay indicated that EGb 761 treatment of colorectal cancer cells induced inhibition of cell migration and invasion ability in a concentration-dependent manner. To further explore the underlying regulatory mechanisms that may account for these findings, we performed quantitative real-time PCR (RT-qPCR), western blotting and immunoprecipitation analysis. The results showed that EGb 761 induced upregulation of LincRNA-p21 expression in a dose- and time-dependent manner. Overexpression of LincRNA-p21 also suppressed colorectal cancer cell metastasis. Furthermore, EGb 761 as well as LincRNA-p21 inhibited the expression of extracellular matrix protein, fibronectin. More importantly, RNA immunoprecipitation (RIP) and Chromatin immunoprecipitation (ChIP) assays showed that LincRNA-p21 directly interacted with EZH2, and this interaction suppressed the expression of fibronectin. Finally, the gain and loss function assay revealed that EGb 761 inhibited migration, invasion and fibronctin expression by the LincRNA-p21/EZH2 pathway in colorectal cancer cells. Hence, EGb 761 may be a promising treatment regimen for colorectal cancer and restoration of LincRNA-p21 levels may be helpful for enhancing the anti-cancer effect of EGb 761.
EGb 761，即标准银杏叶提取物，常用于传统中医。目前，尚无关于其在人类结直肠癌进展中作用的研究。在我们的研究中，我们确定了EGb 761对结直肠癌细胞的抗转移作用，并进一步探索了潜在的调控机制。细胞迁移和侵袭试验表明，用EGb 761处理结直肠癌细胞可浓度依赖性地抑制细胞迁移和侵袭能力。为了进一步探索可能解释这些发现的潜在调控机制，我们进行了定量实时PCR（RT-qPCR）、蛋白质印迹和免疫沉淀分析。结果表明，EGb 761以剂量和时间依赖性方式诱导LincRNA-p21表达上调。LincRNA-p21的过表达也抑制了结直肠癌细胞转移。此外，EGb 761以及LincRNA-p21均抑制细胞外基质蛋白纤连蛋白的表达。更重要的是，RNA免疫沉淀（RIP）和染色质免疫沉淀（ChIP）试验表明，LincRNA-p21直接与EZH2相互作用，这种相互作用抑制了纤连蛋白的表达。最后，功能获得和缺失试验表明，EGb 761通过LincRNA-p21/EZH2途径抑制结直肠癌细胞的迁移、侵袭和纤连蛋白表达。因此，EGb 761可能是一种有前景的结直肠癌治疗方案，恢复LincRNA-p21水平可能有助于增强EGb 761的抗癌效果。
