α-Tocopherol succinate enhances pterostilbene anti-tumor activity in human breast cancer cells in vivo and in vitro.

Abstract

Vitamin E (Vit. E) is considered an essential dietary nutrient for humans and animals. An enormous body of evidence indicates the biological and protective effects of Vit. E consumption. Tocopherol-associated protein (TAP) is a major tocopherol-binding protein affecting Vit. E stimulation and downstream signaling transduction. However, how Vit. E utilizes TAP as an anti-cancer mechanism remains unclear. Microarray analysis of signature gene profiles in breast cancer cells treated with α-tocopheryl succinate (α-TOS, a Vit. E isoform) resulted in cell cycle arrest and anti-cancer activity in breast cancer cells. Pterostilbene (PS), a natural dietary antioxidant found in blueberries, in combination with α-TOS synergistically maximized breast cancer cell growth inhibition by disrupting signal transduction, transcription factors and cell cycle proteins. In a xenograft mouse model, PS treatment with Vit. E inhibited breast tumor growth and cell invasion, which were evaluated using our recently developed circulating tumor cell (CTC) detection assay. Because dietary Vit. E and PS supplementation contributed to preventative and therapeutic effects in vitro and in vivo, this combination may benefit breast cancer therapy in the clinic.

• Authors: Ka-Wai Tam, Chi-Tang Ho, Shih-Hsin Tu, Wen-Jui Lee, Ching-Shui Huang, Ching-Shyang Chen, Chih-Hsiung Wu, Chia-Hwa Lee, Yuan-Soon Ho
• Journal: Oncotarget (Oncotarget) Vol. 9 Issue 4 Pg. 4593-4606 (Jan 12 2018) ISSN: 1949-2553 [Electronic] United States
• PMID: 29435127 (Publication Type: Journal Article)