Abstract
It is long recognised that lung cancer has an increased frequency in idiopathic pulmonary fibrosis (IPF), raising questions regarding the similarity of IPF and lung cancer biology. Matrix metalloproteinases regulate remodelling of the extracellular matrix, an important function for pathological processes such as angiogenesis, tissue repair and tumor invasion. We aim to assess the expression of this pathway in BALF samples of lung cancer patients and compare with IPF patients to examine possible pathogenetic links between these two lethal pulmonary diseases.
We prospectively studied 23 newly diagnosed patients, with non small cell lung cancer (NSCLC), 10 IPF patients and 10 healthy controls (C). MMP2, MMP7, MMP9, TIMP1 and TIMP2 mRNA expression levels were measured in BALF by real time RT-PCR. MMP7 protein levels were measured in BALF supernatants using ELISA kit.
mRNA expression of MMPs 2,7,9 and TIMP1 was significantly increased in lung cancer compared to controls (p<0.05). The IPF population showed decreased expression of the aforementioned MMPs in comparison with lung cancer while did not show significant difference at the mRNA level in comparison to controls. MMP7 protein levels (pg/μl) were significantly higher in both NSCLC and IPF populations compared to controls (NSCLC: 24.69±4.18, IPF: 18.65±2.11, C=9.76±1.92, with p values: NSCLCvsC p=0.032, IPFvsC p=0.005).
Increased expression of MMP-7 in both m-RNA and protein level may suggest a common link between those lethal disorders. Given that our population was newly diagnosed, the over-expression of these markers could be predictive of tumor progression, migratory behaviour and metastasis potential.
- © 2011 ERS