RGCC is a Prognostic Biomarker and Correlates with Immune Infiltrates in Breast Cancer

Background: RGCC (regulator of cell cycle) is a protein-coding gene, also known as RGC-32(response gene to complement 32 protein), which is an important regulatory gene of cell cycle progression. However, the relationship between RGCC and breast cancer prognosis and tumor immune cells remains unclear. Methods and results RGCC differential expression analysis was performed based on TCGA, GEO, UALCAN and HPA databases, respectively. Then, KM curve and ROC curve were constructed to evaluate the prognosis and diagnostic value of RGCC. In addition, Immune Infiltration Analysis was performed by ssGSEA. scTIME and cancerSEA databases were used to illustrate the relationship between RGCC and tumor immune cells at the single-cell level. Subsequently, the clinical relevance of RGCC was discussed and Nomogram and calibration curves were constructed. Finally, R package clusterProfiler was used for enrichment of the GO (Gene Oncology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways to explore the biological function of RGCC. Results Low expression of RGCC in breast cancer was associated with better overall survival (OS) and Disease Specific Survival (DSS), and ROC curve suggested that RGCC had a good diagnostic value. The expression of RGCC was positively correlated with the invasion levels of iDC, Macrophages, Neutrophils, CD8 T cells, and Th1 cells. RGCC was positively correlated with immunoinhibitors TGFB1 and immunostimulators C10orf54, CD40, CXCL12, CXCR4, IL6, NT5E, TNFRSF4, TNFRSF8 and TNFSF9 in BRCA. Single cell data showed that RGCC was highly expressed in Macrophages. RGCC mRNA expression was significantly correlated with Age, Histological type, T stage, HER2 status and PAM50. Mechanistically, we found that RGCC is closely related to cell adhesion and MHC Class II protein complexes. RGCC was associated with angiogenesis in two single-cell datasets. Conclusions RGCC may play an important role in cell proliferation and metastasis, and can be used as a prognostic biomarker to determine the prognosis of BRCA and immune invasion.