1. Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
2. Department of Internal Medicine, Feng Yuan Hospital, Ministry of Health and Welfare, Taiwan.
3. Institute of Biochemistry, Microbiology and Immunology, Chung Shan Medical University, Taichung, Taiwan
4. Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
5. Division of Nephrology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan
6. School of Medicine, Chung Shan Medical University, Taichung, Taiwan
* Yih-Shou Hsieh contributed equally as first author.
Phytochemicals represent an important source of novel anticancer and chemotherapeutic agents. Thymoquinone (TQ) is the major bioactive phytochemical derived from the seeds of Nigella sativa and has shown potent anticancer activities. In this study, we aimed to investigate the anticancer activity of Thymoquinone on the human renal carcinoma cell 786-O-SI3 and the underlying mechanism. By using cell proliferation assay, wound healing, and invasion assay, we found that Thymoquinone did not affect the viability of 786-O-SI3 and human kidney-2, but clearly inhibited the migration and invasion of 786-O-SI3. Further zymography and immunoblotting analysis showed that Thymoquinone downregulated the activity and expression of matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (u-PA) and attenuated the adhesion of 786-O-SI3 to type I and type IV collagen. Kinase cascade assay indicated that Thymoquinone inhibited the phosphorylation of phosphatidylinositol 3-kinase, Akt, Src, and Paxillin. In addition, Thymoquinone also decreased the level of fibronectin, N-cadherin, and Rho A. In parallel, Thymoquinone dose-dependently suppressed the transforming growth factor (TGF)-β-promoted u-PA activity and expression, as well as the cell motility and invasion of 786-O-SI3. Furthermore, tumor xenograft model revealed that Thymoquinone in vivo inhibited the 786-O-SI3 metastasizing to the lung. Collectively, these findings indicate that Thymoquinone inhibits the metastatic ability of 786-O-SI3, suggesting that Thymoquinone might be beneficial to promote the chemotherapy for renal cell carcinoma.
Keywords: thymoquinone, renal carcinoma, invasion, matrix metalloproteinase, urokinase-type plasminogen activator