Lung Cancer in Pulmonary Fibrosis: Tales of Epithelial Cell Plasticity

Lung epithelial cells exhibit a high degree of plasticity.
Alterations to lung epithelial cell function are critically
involved in several chronic lung diseases such as pulmonary
fibrosis. Pulmonary fibrosis is characterized by repetitive injury
and subsequent impaired repair of epithelial cells, which leads to
aberrant growth factor activation and fibroblast accumulation.
Increased proliferation and hyper- and metaplasia of epithelial
cells upon injury have also been observed in pulmonary fibrosis;
this epithelial cell activation might represent the basis for lung
cancer development. Indeed, several studies have provided
histopathological evidence of an increased incidence of lung cancer
in pulmonary fibrosis. The mechanisms involved in the development
of cancer in pulmonary fibrosis, however, remain poorly understood.
This review highlights recently uncovered molecular mechanisms
shared between lung cancer and fibrosis, which extend the current
evidence of a common trait of cancer and fibrosis, as provided by
histopathological observations. Copyright (C) 2011 S. Karger AG,
Basel