Abnormal hypermethylation and clinicopathological significance of FBLN1 gene in cutaneous melanoma.

Fibulin-1 (FBLN1) is involved in the progression of some types of cancer. However, the role of FBLN1 in cutaneous melanoma (CM) has not been examined. The purpose of this study was to understand the molecular mechanisms and clinical significance of FBLN1 inactivation in CM. The expression of FBLN1 mRNA in CM tissues and adjacent normal skin tissues was analyzed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Methylation-specific polymerase chain reaction was performed to examine the methylation status of the FBLN1 gene promoter. Furthermore, the methylation status of FBLN1 was analyzed with the clinicopathological characteristics and overall survival. qRT-PCR showed FBLN1 mRNA levels in cancerous tissues to be significantly decreased compared with that in adjacent normal skin tissues. The rate of FBLN1 promoter methylation was significantly higher in CM tissues than in adjacent normal skin tissues (P < 0.001). Downregulation of FBLN1 was strongly correlated with promoter methylation (P = 0.021). Promoter hypermethylation of FBLN1 was significantly associated with tumor stage (P = 0.019). In addition, FBLN1 methylation status was associated with significantly shorter survival time and was an independent predictor of overall survival. In conclusion, our results indicated that FBLN1 is a novel candidate of tumor suppressor gene and that promoter hypermethylation of FBLN1 is associated with tumor progression in CM.