Cigarette-Smoke-Induced Dysregulation of MicroRNA Expression and Its Role in Lung Carcinogenesis

Figure 1

Simplified overview of the mechanisms by which cigarette smoke induces dysregulation of miRNA (red arrows) and subsequent carcinogenesis. CS can lead to genetic mutations in miRNA transcriptional regulators, like P53. Dysregulation of P53, an activator of miRNA transcription, leads to downregulation of miRNA, like miR-34. CS can also lead to epigenetic or genetic mutations in the miRNA gene itself, leading to dysregulation of transcription. Both downregulation and upregulation of miRNA can allow for cell proliferation if the miRNA is a tumor suppressor or oncogene, respectively. The red arrows indicate direct action of CS on miRNA production. The red “X’s” indicate inhibition of a normal process (indicated by black arrows).