Carmen W H Chan
Chinese University of Hong Kong
Title: Profiling silica-induced molecular events in human lung cells using the RNA-Seq approach
Biography
Biography: Carmen W H Chan
Abstract
Background: Silicosis is a prolonged, irreversible and incurable occupational disease. For better control of this deadly disease, effective and significant biomarkers could be crucial. This study showed the possible immediate molecular pathogenic events in lung epithelial cells underlying sub-lethal silica exposure from 30 minutes to 24 hours, using the high-throughput RNA-Seq approach.
Method: A549 cells were treated with crystalline silica at 20% cytotoxicity (max.) to allow the investigation of the inflammatory and fibrotic effects of silica particles. Then, total RNA was extracted and mRNA was enriched using the ribosomal RNA depletion kit. The enriched mRNA was reverse-transcribed to prepare transcriptome library for RNA-Seq analysis in an Illumina HiSeq2000 genetic analyzer. The filtered transcriptome sequence data generated was assembled and mapped to the human reference genome to determine the differentially expressed genes. Significant differentially expressed candidate genes will be verified by real-time PCR followed by comprehensive pathway analysis using DAVID 6.7.
Results: From the RNA seq results, it was found that several molecular pathways were significantly highlighted in silica exposed cellular changes. These include known pathways for silicosis such as inflammatory responses and oxidative stress responses. Other mechanisms on transcription factor regulation, aldehyde dehydrogenase and blood vessel development was newly reported to be associated with silicosis. The changes of expression level of genes under these pathways were confirmed by quantitative PCR (qPCR). In future, it is important to characterize the relationship of newly found pathways and silicosis in order to discover the novel biomarkers.
Conclusion: In this study, by RNA sequencing analysis, several pathways on transcription factor regulation, aldehyde dehydrogenase and blood vessel development were newly described to be involved in silica treatment on lung cells. Hopefully, novel biomarkers of silicosis could be discovered in future.