Blood gene expression changes in response to exposure to dust containing silica

Occupational exposure to dust containing crystalline silica may result in serious adverse health effects including silicosis and cancer. Previous studies which employed animal models for inhalation exposure to crystalline silica revealed changes in blood gene expression profiles in association with the silica-induced lung toxicity. Currently, global gene expression profiles were determined in the whole blood samples obtained from control (not exposed to dust) and dust containing silica exposed individuals with or without clinically identified silicosis. Differences in the blood gene expression profiles were detected in the blood samples obtained from the control and the silica-containing dust exposed individuals. Between the two groups of the silica-containing dust exposed individuals, the number of significantly differentially expressed genes was more in the blood samples obtained from those with silicosis. Overall design: Whole blood samples collected from individuals who were exposed to dust containing silica were used in the study. Blood samples collected from an unexposed, matching cohort were used as the controls (CTl2 to CTl60) (n = 23). The lung function and silicosis status of the study participants were determined by spirometry and chest x-ray, respectively. Based on the results of chest x-ray, the silica exposed subjects were classified into two groups – dust exposed with silicosis (TESC_02 to TESC_40) (n = 30) and dust exposed without silicosis (TESC_42 to TESC_89) (n = 33). Gene expression profiles were determined by next generation sequence analysis in the blood samples collected from the subjects.