Nano-TiO_2 Drives Epithelial-Mesenchymal Transition in Intestinal Epithelial Cancer Cells

摘要

The majority of cancer mortality is associated with cancer metastasis. Epithelial-to-mesenchymal transition (EMT) is a process by which cells attain migratory and invasive properties, eventually leading to cancer metastasis. Here, it is shown that titanium dioxide nanoparticles (nano-TiO_2), a common food additive, can induce the EMT process in colorectal cancer cells. Nano- TiO_2 exposure is observed to activate transforming growth factor-β (TGF-β)/ mitogen-activated protein kinase (MAPK) and wingless (Wnt) pathways, and drive the EMT process. Similarly, silica nanoparticles (nano-SiO_2) and hydroxyapatite nanoparticles (nano-HA), as food-based additives, can be ingested and accumulated in the stomach, and are found to be able to induce the EMT progression. The implication of this work can be profound for colorectal cancer patients where these food additives may unknowingly and unnecessarily hasten the progression of their cancers.