Smoking and microRNA dysregulation: a cancerous combination

• The unique miRNA-based signatures distinguish healthy controls from cancer cases with high sensitivity and specificity.
• Differential expression pattern of miRNAs in various malignancies varies with smoking status of individuals.
• Smoking mediates its impact by modulating tumor-suppressive miRNAs during neoplastic transformation and oncogenic miRNAs at later stages of cancer.
• miRNAs are probably involved in smoking-induced modulation of signaling cascades in various cancers.

MicroRNAs (miRNAs) are post-transcriptional gene regulators that are differentially expressed in several pathophysiological conditions including cancer. They impact the disease course by modulating an array of putative target gene(s). Interestingly, there is a strong correlation between the various miRNAs target(s) and the smoking-regulated genes in cancer. This review article provides an insight into the current status of smoking-induced miRNAs and their genetic/epigenetic regulation in smoking-associated cancers, with a major focus on lung cancer (LC). Furthermore, it discusses the role of miRNAs in smoking-mediated oncogenic events in cancer and explores the diagnostic/prognostic potential of miRNA-based biomarkers and their efficacy as therapeutic targets.