Background: Esophageal squamous cell carcinoma (ESCC) is one of the most common
cancers with high mortality rate. Cigarette smoke and chewing tobacco are well known risk factors associated
with ESCC. However, molecular mechanisms associated with development of ESCC among
smokers and chewers are poorly understood. MicroRNAs play an important role in regulating physiological
and disease processes including esophageal cancer.
Objective and Methods: In this study, we developed an in vitro model by treating non-neoplastic Het-
1A esophageal cell line with cigarette smoke and chewing tobacco. We carried out miRNA sequencing
on Illumina HiSeq 2500 platform and compared miRNA expression pattern across cigarette smoke
and chewing tobacco treated Het-1A cells with untreated cells.
Results: We identified and quantified 433 miRNAs in both smoke exposed and chewing tobacco
treated cells, of which 13 miRNAs showed significantly altered expression in cigarette smoke exposed
cells while 25 miRNAs showed significantly altered expression in chewing tobacco treated cells. In
addition, we predicted novel miRNAs from these data-sets. We evaluated miRNAs that showed selective
or context dependent expression pattern in cigarette smoke exposed or chewing tobacco treated cells.
Conclusion: In this study, we have comprehensively mapped miRNA expression pattern in response
to cigarette smoke and chewing tobacco in Het-1A cells. We identified miRNAs that show altered expression
in these cell models.