Background: Metastasis is the major characteristic of malignant carcinomas, which has been found to be linked with epithelial to mesenchymal transitions (EMT). Regulation of EMT process can provide a significant beneficiary effect to control metastasis, as well as to treat cancers. In this study we have investigated the effects of natural product Thymoquinone in metastatic cancer cell lines to evaluate their role in metastatic characteristics linked to EMT process.

Methods: We have treated HeLa and MDA-MB-435 human cancer cell lines with Thymoquinone, and analyzed the cell proliferation, migration and invasion, which are the major metastatic characteristics, by using the real-time cell analyzer. The real-time PCR and Western blot analysis was employed for the determination of the cellular expression of major EMT-associated proteins N-cadherin and E-cadherin; their transcription factors Twist, Snail, Slug and Zeb; and another important metastatic protein Vimentin.

Results: Thymoquinone was found to inhibit the migratory and invasive characteristics in both cancer cell lines dose dependently, and effective in a low dose eventually (1-5 μM). Its cytotoxicity has also been confirmed by MTT assay for cell viability. Genetic expression analysis showed that Thymoquinone significantly down-regulates the mRNA expression of cell adhesion protein N-cadherin in HeLa cell. Thymoquinone also down-regulates the transcription factor Twist, which is being considered as an oncoprotein. Thymoquinone has mild to moderate effect on the expression pattern of other metastatic proteins in HeLa cells. In MDA-MB-435, Thymoquinone treatment downregulates Twist, Snail, Vimentin and N-cadherin. However, N-cadherin expression was found in extremely low in both untreated and treated MDA-MB-435.

Conclusions: We report that the prospective anticancer molecule Thymoquinone down-regulates N-cadherin and its transcription factors like Twist and Snail, which might have a significant influence on the effects of Thymoquinone in controlling cell migration and invasion. Further research is necessary for the investigation of this compound in specific cancer types with mechanisms in detail.

Fund support: This work was supported in part by the National Natural Science Foundation of China (81172049, 30371493), Science and Technology Innovation Team of Colleges and Universities of Sichuan Province (13TD0032).

Citation Format: Md. Asaduzzaman Khan, Manman Yang, Chunli Wei, Lin Gan, Junjiang Fu. Thymoquinone downregulates n-cadherin, twist and snail expression and inhibits migration and invasion in cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5009. doi:10.1158/1538-7445.AM2014-5009