Association of CXCL14 in the Human Airway Epithelium with Chronic Obstructive Lung Disease and Lung Cancer

CXCL14, a recently described chemokine constitutively expressed in various epithelia, has multiple putative roles in inflammation and carcinogenesis. Based on the knowledge that cigarette smoking and the smoking-induced disorders, such as chronic obstructive pulmonary disease (COPD) and lung cancer, are associated with inflammation, we hypothesized that the airway epithelium, the primary site of smoking-induced pathologic changes in COPD and adenocarcinoma, responds to cigarette smoking with an altered CXCL14 gene expression as a part of disease-relevant molecular phenotype. Microarray analysis with subsequent TaqMan PCR validation revealed very low constitutive CXCL14 gene expression in the airway epithelium of healthy nonsmokers (n=53) which was strongly up-regulated in healthy smokers ( n=59; p<0.001) and further increased in COPD smokers (n=23; p<10-7 vs nonsmokers; p<0.005 vs healthy smokers). In smokers, CXCL14 expression inversely correlated with lung function parameters FEV1 and FEV1/FVC. Genome-wide analysis also showed that up-regulated correlation of CXCL14 expression with genes related to cell growth and proliferation, squamous differentiation and cancer. The analysis of 193 lung adenocarcinoma samples demonstrated a dramatic up-regulation of CXCL14 in a smoking-dependent manner. [need to include survival data once we get it]. Together, these data suggest that smoking-induced expression of CXCL14 in association with genome-wide reprogramming of processes related to tissue homeostasis, differentiation and tumorigenesis, represents a novel molecular link between cigarette smoking, COPD and lung cancer. Affymetrix arrays were used to assess the expression of CXCL14 gene expression data in small airway epithelium obtained by fiberoptic bronchoscopy of 53 healthy non-smokers and 59 healthy smokers and 23 smokers with COPD.