Oncology Insights 2023-03-05T18:34:43+00:00 Oncology Insights Open Journal Systems <p><strong>Oncology Insights</strong> is an international open-access peer-reviewed journal, based on a continuous publication model, and aims to publish original works of high quality, covering all the fields of oncology.</p> Integrative Analysis of Genetic and Epigenetic Alterations in the CBX7 Gene Reveals Its Tumor-Suppressive Function by Regulating the Cell Cycle in Human Breast Cancer 2023-01-11T17:17:25+00:00 Yimeng Cai Hang Chang Jesus Perez-Losada Jian-Hua Mao <p><em>CBX7</em> is a member of the chromobox gene family, which plays an important role in epigenetic transcriptional regulation. In this study, we found that compared to normal mammary tissues, mRNA levels of <em>CBX7</em> are consistently significantly downregulated in breast cancers (BCs) across different datasets. Integrative multiomics analysis revealed the genetic and epigenetic mechanisms for the loss of <em>CBX7</em> expression in BCs. Lower expression levels of <em>CBX7</em> are significantly associated with shorter overall, disease-free, and distant metastasis-free survival of patients with BC. These prognostic impacts of <em>CBX7</em> are independent of estrogen receptor status and PAM50 molecular subtypes. Coexpression analysis identified 207 genes consistently coexpressed with <em>CBX7</em> (157 negatively and 50 positively). Gene Ontology, KEGG, and Reactome enrichment analysis revealed that cell cycle‑, DNA replication‑, and mitosis-related pathways are significantly overrepresented within the set of <em>CBX7</em> negatively coexpressed genes, suggesting that <em>CBX7 </em>functions as a suppressor of the cell cycle. Moreover, transcription factor enrichment analysis detected the E2F family of transcription factors significantly associated with <em>CBX7</em> negatively coexpressed genes, consistent with E2F function regulating the cell cycle. Furthermore, we found that loss of <em>CBX7</em> expression significantly increases genomic instability and tumor mutation burden. Our findings indicate that <em>CBX7</em> acts as a tumor suppressor in BC through its potential role in the negative regulation of cell proliferation and the maintenance of genome integrity.</p> 2023-03-05T00:00:00+00:00 Copyright (c) 2023 Cai Y et al.