Expression and Clinical Significance of Origin Recognition Complex Subunit 6 in Breast Cancer – A Comprehensive Bioinformatics Analysis

Clinical relevance of ORCs in predicting prognosis and immunotherapy outcomes: A pan-cancer analysis

BACKGROUND

The origin recognition complex (ORC) consists of six subunits and mediates DNA replication by binding to its origin. Recent studies show that ORCs are closely related to various biological processes in tumors. However, a comprehensive study of ORCs in pan-cancer has not been conducted.

RESULTS

A systematic evaluation of the expression, mutation, and prognostic significance of ORCs was conducted across cancer types using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. The single-sample Gene Set Enrichment Analysis (ssGSEA) was performed using R package "Gene Set Variation Analysis (GSVA)" to evaluate ORC score. ORC score was significantly elevated in most cancers and linked with an inferior prognosis. It was positively related to the G2/M checkpoint and DNA repair pathways. An elevated ORC score also correlated with tumor mutation burden (TMB)/ microsatellite instability (MSI). A prognosis analysis suggested that high ORC scores were associated with heightened immunotherapeutic sensitivity.

CONCLUSIONS

Our research elucidates the genomic changes associated with and clinical relevance of ORCs in cancer and provides unique insights for future investigation of ORCs in immunotherapy.

Multi-omics analysis reveals the involvement of origin recognition complex subunit 6 in tumor immune regulation and malignant progression

Background

Origin recognition complex 6 (ORC6) is one of the six highly conserved subunit proteins required for DNA replication and is essential for maintaining genome stability during cell division. Recent research shows that ORC6 regulates the advancement of multiple cancers; however, it remains unclear what regulatory impact it has on the tumor immune microenvironment.

Methods

Unpaired Wilcoxon rank sum and signed rank tests were used to analyze the differences in the expression of ORC6 in normal tissues and corresponding tumor tissues. Multiple online databases have evaluated the genetic alterations, protein expression and localization, and clinical relevance of ORC6. To evaluate the potential prognostic impact and diagnostic significance of ORC6 expression, we carried out log-rank, univariate Cox regression, and receiver operating characteristic curve analysis. The ICGC-LIRI-JP cohort, CGGA-301 cohort, CGGA-325 cohort, CGGA-693 cohort, and GSE13041 cohort were used for external validation of the study findings. The associations between ORC6 expression and immune cell infiltration, immune checkpoint expression, and immunotherapy cohorts was further analyzed. To explore the functional and signaling pathways related to ORC6 expression, gene set enrichment analysis was performed. To clarify the expression and function of ORC6 in hepatocellular carcinoma (LIHC) and glioma, we conducted in vitro experiments.

Results

Expression of ORC6 is upregulated in the majority of cancer types and is associated with poor patient prognosis, notably in cases of LIHC and gliomas. In addition, ORC6 may be involved in multiple signaling pathways related to cancer progression and immune regulation. High expression of ORC6 correlates with an immunosuppressive state in the tumor microenvironment. The results of further immunotherapy cohort analysis suggested that patients in the ORC6 high-expression group benefited from immunotherapy. Inhibiting ORC6 expression suppressed the proliferative and migratory abilities of LIHC and glioma cells.

Conclusion

High expression of ORC6 may be used as a biomarker to predict the poor prognosis of most tumor patients. The high expression of ORC6 may be involved in the regulation of the tumor immunosuppressive environment, and it is expected to become a molecular target for inhibiting tumor progression.