SLAMF6 appears bidirectional in immune regulation of different cancers

Background: Signaling lymphocyte activation molecule family 6 (SLAMF6) is widely expressed in T lymphocytes, B lymphocytes, NK cells and other immune cells. Its role in the initiation and progression of human cancer has recently attracted attention. To date, SLAMF6 has been studied only in melanoma, chronic lymphocytic leukemia, liver cancer, etc. And its role in other types of tumors still needs to be further explored. We studied the mutation, expression and immune regulation of SLAMF6 at the pan-cancer level, so as to more systematically and comprehensively understand the role of SLAMF6 in the occurrence and development of a variety of malignant tumors. Methods: We obtained the gene expression profiles of tumor and corresponding normal tissues from The Cancer Genome Atlas (TCGA) and Genotype - Tissue Expression (GTEx) database, and analyzed the data using multiple online platforms and software, including R, Cytoscape, HPA, Archs4, TISIDB, cBioPortal, STRING, GSCALite, and CancerSEA. Results: Compared to normal tissues, SLAMF6 is highly expressed in a variety of cancers, which acts as a risk factor in UVM and LGG, and acts as a protective factor in CESC, LIHC and SKCM. Also, SLAMF6 is differentially expressed in molecular and immune subtypes of a variety of cancers. Moreover, SLAMF6 can be used as a prognostic marker for many cancers. Its expression is positively correlated with Act CD8 cells, Tem CD8 cells, Act B cells and Imm B cells, and negatively correlated with CD56dim, iDC in most cancers. In addition to the infiltration levels of immune cells, SLAMF6 is positively or negatively correlated with MHCs, immunostimulators, immunoinhibitors, cytokines and cytokine receptors in various cancers. Conclusions: We explored the role SLAMF6 plays in promoting, inhibiting and treating different cancers. SLAMF6 is a potential biomarker for cancer diagnosis and prognosis. Its regulatory effect on immunity in tumor tissue may be bidirectional, and the regulatory effect may be reversed depending on the microenvironment of different tumor types. This work provides a new insight into the role of SLAMF6 in tumor immunity and also provides a reference for targeted therapies against SLAMF6.