Expression and clinicopathological significance of microRNA-21 and programmed cell death 4 in malignant melanoma.

OBJECTIVE

To measure levels of microRNA (miR)-21 and its target gene, programmed cell death 4 (PDCD4), in samples of human cutaneous malignant melanoma and normal non-malignant control skin.

METHODS

Relative levels of miR-21 and PDCD4 mRNA were measured using a quantitative real-time reverse transcription-polymerase chain reaction. Correlations between the levels of the two molecules and the clinicopathological characteristics of malignant melanoma were analysed.

RESULTS

A total of 67 cases of human cutaneous malignant melanoma were analysed and compared with 67 samples of normal nonmalignant control skin. Compared with normal skin samples, the relative level of miR-21 was significantly higher and the relative level of PDCD4 mRNA was significantly lower in the melanoma specimens. A significant negative correlation between PDCD4 mRNA and miR-21 was demonstrated in malignant melanoma (r = -0.602). Elevated miR-21 and reduced PDCD4 mRNA levels were both significantly correlated with increased tumour size, a higher Clark classification level and the presence of lymph node metastases in malignant melanoma.

CONCLUSIONS

These findings suggest that miR-21 and PDCD4 might be potential biomarkers for malignant melanoma and might provide treatment targets in the future.