Overexpression of FAM136A predicts an adverse prognosis in skin cutaneous melanoma

FAM136A, as a family with sequence similarity 136 member A, is involved in the occurrence and development of some tumors. However, the function of FAM136A in skin cutaneous melanoma(SKCM) is rarely known. We used TCGA, GTEx, and GEO databases to compare differential expression of FAM136A in SKCM and normal tissues. We performed immunohistochemistry(IHC) to study the protein expression of FAM136A in SKCM. Then we discussed the correlation of FAM136A expression with clinical features. Kaplan-Meier was drawn to study the clinical prognosis of FAM136A in SKCM. Cox regression analyses were performed to determine independent factors influencing overall survival (OS) and disease specific survival (DSS). The correlative analysis between FAM136A and immune cell infiltration was investigated by ssGSEA and ESTIMATE algorithm. The relationship of FAM136A expression with immune checkpoints was studied by Spearman analysis. GSEA was used to evaluate the function of FAM136A in SKCM. The results of TCGA and GTEx database showed that FAM136A had higher expression in SKCM than in normal tissues. GEO database had a similar result. IHC results suggested that FAM136A protein expression had higher in SKCM than normal tissues. High expression of FAM136A showed lower OS and DSS in SKCM, and FAM136A had independent influence on OS and DSS in SKCM. FAM136A expression was positively related to Th2, T helper cells, ​Tcm and Tgd. The stromalscore, immunescore, and estimatescore were higher in low FAM136A expression than in high FAM136A expression. FAM136A expression was positively related to some immune checkpoints, especially PDCD1(PD-1). GSEA results showed that FAM136A-related genes were partook the cell cycle, homologous recombination, basal transcription factors, DNA replication, mismatch repair, and the TGF-β signaling pathway. FAM136A overexpression in SKCM independently predicts poor OS and DSS and is closely associated with immune cell infiltration and PDCD1 expression, highlighting its potential as a prognostic biomarker and immunotherapeutic target.