Background: Colon cancer is the most commonly diagnosed cancer both in men and women and cause of cancer related deaths worldwide. Treatment for the recurrent and metastatic colon cancer remains a center of clinical attention. Cancer stem cells (CSCs) are suggested to be the only cells within tumor with tumorigenic capacity and implicated in metastasis. We have shown that vitamin E delta-tocotrienol (VEDT) is the most bioactive tocotrienols against cancers. This study aimed to evaluate the effect of VEDT on colon cancer growth, metastatic epithelial to mesenchymal transition (EMT), migration/ invasion/angiogenesis and colon CSCs growth and apoptosis.
Methods: Human colon cancer cells HCT-116 and metastatic colon cancer cells SW-620 and colon CSCs were treated with VEDT (10-100 μM) for 72 h and cell viability recorded. VEDT (50 μM) was used for malignant transformation; migration/invasion, CSCs spheroid formation, and pluripotency were determined. Azoxymethane treated Fisher 344 rats were used as colon carcinogenesis model. They were treated with 1) vehicle control and 2) VEDT (200 mg/kg, orally twice a day) for 20 weeks. After 20 weeks the polyps and tumor formation were recorded.
Results: VEDT significantly inhibited the anchorage-dependent and independent cancer cell growth, migration/invasion and induced apoptosis compared to control. VEDT inhibited the CSC spheroid formation EMT (E-cadherin to vimentin), metastasis (MMP9), angiogenesis (VEGF), CSCs transcription factors (Nanog, Oct4, Sox2 and KLF4) compared to control.
Conclusion: Vitamin E delta-tocotrienol inhibited colon cancer growth and metastasis through inhibition of cancer stem cell pluripotency, EMT, migration, invasion, angiogenesis and induction of apoptosis.
Citation Format: Kazim Husain, Domenico Coppola, Said M. Sebti, Mokenge P. Malafa. Vitamin E delta-tocotrienol targets human colon cancer stem cells and inhibits colon cancer metastasis and induces apoptosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3839.