Arsenic-exposed Keratinocytes Exhibit Differential microRNAs Expression Profile; Potential Implication of miR-21, miR-200a and miR-141 in Melanoma Pathway

Background: Long-term exposure to arsenic has been linked to cancer in different organs and tissues, including skin. Methods: Here, non-malignant human keratinocytes (HaCaT) were exposed to arsenic and its effects on microRNAs (miRNAs; miR) expression were analyzed via miRCURY LNA array analyses. Results: A total of 30 miRNAs were found differentially expressed in arsenic-treated cells, as compared to untreated controls. Among the up-regulated miRNAs, miR- 21, miR-200a and miR-141, are well known to be involved in carcinogenesis. Additional findings confirmed that those three miRNAs were indeed upregulated in arsenic-stimulated keratinocytes as demonstrated by quantitative PCR assay. Furthermore, bioinformatics analysis of both potential cancer-related pathways and targeted genes affected by miR-21, miR-200a and/or miR-141was performed. Results revealed that miR-21, miR-200a and miR-141 are implicated in skin carcinogenesis related with melanoma development. Conclusion: Conclusively, our results indicate that arsenic-treated keratinocytes exhibited alteration in the miRNAs expression profile and that miR-21, miR-200a and miR-141 could be promising early biomarkers of the epithelial phenotype of cancer cells and they could be potential novel targets for melanoma therapeutic interventions.