Abstract
BACKGROUND: Transmembrane p24 trafficking protein 9 (TMED9) belongs to the TMED family, and its overexpression frequently induces cancer. Studies have demonstrated the association between the overexpression of TMED9 and cancer development and proliferative migration in cancers such as ovarian cancer, hepatocellular carcinoma, and breast cancer. However, there has been no study investigating the clinical value, biological function, and anti-tumor immune effects of TMED9 from a pan-cancer perspective. The aim of this study is to evaluate the prognostic value and anti-tumor immunity role of TMED9 across pan-cancers. METHODS: We utilized R language along with The Cancer Genome Atlas (TCGA), UCSC Xena (University of California, Santa Cruz Xena Browser), Human Protein Atlas (HPA), and other datasets to investigate TMED9 expression in various tumors. The association between high TMED9 expression and clinical prognosis and patient survival was examined using the Kaplan-Meier method, log-rank test, as well as univariate and multivariate Cox regression analyses. Tumor Immune Estimation Resource 2.0 (TIMER2.0) and various algorithms were employed to explore the relationship between TMED9 and the tumor microenvironment (TME). Additionally, the biological function of TMED9 in cancer was investigated through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) analyses. RESULTS: TMED9 was over-expressed in the majority of cancers. Patients exhibiting elevated TMED9 expression typically experienced diminished survival rates and unfavorable clinical outcomes. TMED9 played a role as a mediator in the aggressive phenotype of numerous tumors, actively engaging in various biological and signaling pathways linked to cancer development. TMED9 demonstrated the capacity to modulate the anti-tumor immune response in pan-cancer patients, exerting its influence on the infiltration levels of immune cells and cancer-associated fibroblasts (CAFs). CONCLUSIONS: TMED9 serves as a novel "cancer indicator" and "clinical prognostic marker", capable of reshaping the TME, impacting the immunotherapeutic response, and guiding precise treatments for cancers to a certain extent.