Expression and Functional Characterization of miR-34c in Cervical Cancer.

BACKGROUND

Cervical cancer is the fourth most common cancer in women and is usually associated with human papillomavirus infection. Viral infections are usually characterized by morphological changes of epithelial cells; however, it is difficult to determine using recently available screening methods whether the changes are caused by productive infection or by malignant disease. Thus, new efforts are required to find novel diagnostic biomarkers of cervical cancer, such as miRNAs, which are small non-coding RNAs involved in the regulation of gene expression.

MATERIALS AND METHODS

miR-34c levels in cervical cancer cell lines were determined by the droplet-digital polymerase chain reaction. Changes in miR-34c expression in vitro were achieved by transient transfection with a specific miRNA mimic and inhibitor oligonucleotides. Cell proliferation was analyzed by crystal violet staining followed by spectrophotometric measurements. The effect on migratory properties was studied using a „scratch“ assay. Western blotting analysis was used to determine the expression of selected proteins.

RESULTS

The downregulation of miR-34c expression was associated with a slight increase in cellular proliferation and a significant increase in cell migration. The analysis of miR-34c expression performed on a set of 39 dysplastic tissues and 35 samples of healthy controls subsequently revealed a significant difference (p < 0.01) in the level of this miRNA.

CONCLUSION

Comparative expression analysis revealed lower expression of miR-34c in cervical precanceroses than in normal untransformed epithelium. in vitro modulation of miR-34c expression revealed its tumor suppressor role in cervical  malignancies. Key words: cervical cancer - HPV - miRNA - HSIL - hsa-miR-34c - precancerosis This work was supported by the projects MEYS - NPS I - LO1413, P206/12/G151 and MH CZ - DRO (MMCI, 00209805). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.  The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Accepted: 16. 7. 2018.