Over-Expressed Twist Associates with Markers of Epithelial Mesenchymal Transition and Predicts Poor Prognosis in Breast Cancers via ERK and Akt Activation.

Yong-Qu Zhang,Xiao-Long Wei,Wei-Ling Chen,Cai-Wen Du,Fan Zhang,Wen-He Huang,Guo-Jun Zhang,Si-Qi Qiu,Yuan-Ke Liang,Jing-Wen Bai,Aamir Ahmad

doi:10.1371/journal.pone.0135851

Abstract

Overexpression of Twist, a highly conserved basic helix-loop-helix transcription factor, is associated with epithelial-mesenchymal transition (EMT) and predicts poor prognosis in various kinds of cancers, including breast cancer. In order to further clarify Twist’s role in breast cancer, we detected Twist expression in breast cancer tissues by immunohistochemistry. Twist expression was observed in 54% (220/408) of breast cancer patients and was positively associated with tumor size, Ki67, VEGF-C and HER2 expression. Conversely, Twist was negatively associated with estrogen receptor (ER), progesterone receptor (PgR) and E-cadherin expression. Patients with Twist expression had a poorer prognosis for 30-month disease free survival (DFS) (82.9%) than patients with negative Twist (92.3%). Overexpression of Twist led to dramatic changes in cellular morphology, proliferation, migratory/invasive capability, and expression of EMT-related biomarkers in breast cancer cells. Moreover, we show that Twist serves as a driver of tumorigenesis, as well as an inducer of EMT, at least in part, through activation of the Akt and extracellular signal-regulated protein kinase (ERK) pathways which are critical for Twist-mediated EMT. Our results demonstrate that Twist expression is an important prognostic factor in breast cancer patients.

Highlights

Breast cancer is the most frequently diagnosed cancer and accounts for 22.9% of all cancers in women worldwide[1]
To examine the Twist and related epithelial-mesenchymal transition (EMT) marker expression levels, five human breast cancer cell lines were used for Western blot and real-time RT-PCR analysis, of which, MCF-7 and T47D are classified as luminal A, SKBR3 as HER2-overexpressed, and MDA-MB231 and BT549 as triple-negative
Quantitative real-time PCR results showed that Twist, ERα, E-cadherin and vimentin mRNA levels were consistent with the protein levels detected by Western blot analysis (Fig 1B)