Decreased Expression of CPEB3 Predicts a Poor Prognosis in Patients with Melanoma: A Study Based on TCGA Data

Aim: Cytoplasmic polyadenylation element-binding protein 3 (CPEB3) has been acknowledged as a tumor-suppressive gene in several cancers; however, there are few reports on the clinical significance of CPEB3 in melanoma. The aim of this study was to investigate the role of CPEB3 in predicting the prognosis of melanoma patients.

Methods: The association of CPEB3 expression and clinical pathologic features was performed using The Cancer Genome Atlas (TCGA) data set. The role of CPEB3 expression in prognosis was also analyzed. In addition, CPEB3 expression-related pathways were enriched by gene set enrichment analysis (GSEA). Association analysis of CPEB3 gene expression and immune infiltration was performed by ssGSEA.

Results: The mRNA was significantly less in melanoma than in normal tissues (p < 0.001). The decrease in CPEB3 expression in melanoma was significantly correlated with T staging (p < 0.001), clinical staging (p = 0.029), melanoma Clark level (p = 0.014), and melanoma ulceration (p = 0.003), while it was marginally significant in N staging (p = 0.089). Melanoma with low CPEB3 expression was associated with worse OS (overall survival), progression-free survival (PFS), and disease-specific survival (DSS) than in that with high expression. In the univariate analysis, expression of CPEB3, melanoma ulceration, Clark level of melanoma, age, clinical stage, T stage, and N stage were correlated with OS (p < 0.05). Further analysis by multivariate Cox regression showed that N stage (p = 0.029), melanoma ulceration (p = 0.004), and CPEB3 expression (p < 0.001) were independent prognostic factors of OS in melanoma. Moreover, GSEA showed that several pathways were enriched in CPEB3, such as PD1 signaling, CTLA4 pathway, CTCF pathway, CHEMOKIN signaling, VEGF signaling, and JAK-STAT pathway. CPEB3 was significantly correlated with the infiltration level of B cells (p < 0.001), T cells (p < 0.001), T helper cells (p < 0.001), and central memory T (Tcm) cells (p < 0.001).

Conclusion: CPEB3 may be a potential prognostic marker in melanoma with poor survival. Moreover, PD1 signaling, CTLA4 pathway, CTCF pathway, CHEMOKIN signaling, VEGF signaling, and JAK-STAT pathway may be the key pathway regulated by CPEB3. Moreover, the expression of CPEB3 in melanoma is related to the level of immune infiltration.