Decreased expression of predicts a poor prognosis in melanoma using bioinformatics analysis.

BACKGROUND

It has been established that the scavenger receptor class A member 5 () functions as a tumor suppressor gene in various cancer types. To our knowledge, no comprehensive study has hitherto investigated the expression and function of in melanoma. This study aimed to determine the association between and melanoma.

METHODS

Analysis of mRNA expression was performed using The Cancer Genome Atlas (TCGA) data sets. To evaluate the clinical significance of , the clinical data of 93 patients with melanoma were collected. The role of expression in prognosis was also analyzed. In this study, survival was evaluated by Kaplan-Meier analysis and compared using the log-rank test. Univariate and multivariate Cox proportional hazard regression analyses were used to identify independent predictors. The Kyoto Encyclopedia of Genes and Genomes, Gene Ontology, and gene set enrichment analysis (GSEA) were used to perform gene set functional annotations. Protein-protein interaction (PPI) networks were constructed to illustrate gene-gene interactions. The Tumor IMmune Estimation Resource (TIMER) database was used to explore the association between and immune infiltration levels.

RESULTS

The results showed that the mRNA expression in melanoma was significantly lower than in adjacent normal skin tissue ( < 0.001). Moreover, decreased expression of in melanoma correlated with the tumor, node, and metastasis (TNM) stage and recurrence ( < 0.05). The overall survival (OS) was significantly higher in melanoma with high expression compared with low expression ( < 0.001). During univariate analysis, expression, tumor (T) stage, node (N) stage, metastasis (M) stage, and recurrence correlated with OS ( < 0.05). Further multivariate Cox regression analysis showed that expression ( = 0.012) could be an independent prognostic factor for OS in cutaneous malignant melanoma. GSEA analysis showed that was significantly enriched in various pathways, such as response to developmental biology and response to antimicrobial peptides. Correlation analysis showed a positive correlation with CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells ( < 0.05), and a negative correlation with tumor purity ( < 0.05).

CONCLUSION

has significant potential as a prognostic biomarker and as a promising therapeutic target in melanoma. Furthermore, expression in melanoma is related to the level of immune infiltration.