Husain Kazim, Centeno Barbara A, Coppola Domenico, Trevino Jose, Sebti Said M, Malafa Mokenge P
Departments of Gastrointestinal Oncology, Tampa, FL, USA.
Departments of Pathology, Tampa, FL, USA.
Oncotarget. 2017 May 9;8(19):31554-31567. doi: 10.18632/oncotarget.15767.
The growth, metastasis, and chemotherapy resistance of pancreatic ductal adenocarcinoma (PDAC) is characterized by the activation and growth of tumor-initiating cells in distant organs that have stem-like properties. Thus, inhibiting growth of these cells may prevent PDAC growth and metastases. We have demonstrated that δ-tocotrienol, a natural form of vitamin E (VEDT), is bioactive against cancer, delays progression, and prevents metastases in transgenic mouse models of PDAC. In this report, we provide the first evidence that VEDT selectively inhibits PDAC stem-like cells. VEDT inhibited the viability, survival, self-renewal, and expression of Oct4 and Sox2 transcription factors in 3 models of PDAC stem-like cells. In addition, VEDT inhibited the migration, invasion, and several biomarkers of epithelial-to-mesenchymal transition and angiogenesis in PDAC cells and tumors. These processes are critical for tumor metastases. Furthermore, in the L3.6pl orthotopic model of PDAC metastases, VEDT significantly inhibited growth and metastases of these cells. Finally, in an orthotopic xenograft model of human PDAC stem-like cells, we showed that VEDT significantly retarded the growth and metastases of gemcitabine-resistant PDAC human stem-like cells. Because VEDT has been shown to be safe and to reach bioactive levels in humans, this work supports investigating VEDT for chemoprevention of PDAC metastases.
胰腺导管腺癌(PDAC)的生长、转移和化疗耐药性的特征是具有干细胞样特性的肿瘤起始细胞在远处器官中的激活和生长。因此,抑制这些细胞的生长可能会阻止PDAC的生长和转移。我们已经证明,δ-生育三烯酚,一种天然形式的维生素E(VEDT),对癌症具有生物活性,可延缓进展,并在PDAC转基因小鼠模型中预防转移。在本报告中,我们提供了首个证据,证明VEDT可选择性抑制PDAC干细胞样细胞。VEDT在3种PDAC干细胞样细胞模型中抑制了细胞活力、存活、自我更新以及Oct4和Sox2转录因子的表达。此外,VEDT抑制了PDAC细胞和肿瘤中的迁移、侵袭以及上皮-间质转化和血管生成的几种生物标志物。这些过程对肿瘤转移至关重要。此外,在PDAC转移的L3.6pl原位模型中,VEDT显著抑制了这些细胞的生长和转移。最后,在人PDAC干细胞样细胞的原位异种移植模型中,我们表明VEDT显著延缓了吉西他滨耐药的人PDAC干细胞样细胞的生长和转移。由于VEDT已被证明是安全的,并且在人体中可达到生物活性水平,这项工作支持研究VEDT用于PDAC转移的化学预防。