APOBEC3A suppresses cervical cancer via apoptosis

Background: Family members of Apolipoprotein B mRNA-editing enzyme catalytic 3 (APOBEC3) play critical roles in cancer evolution and development. However, the role of APOBEC3A in cervical cancer remains to be clarified. Methods: We used bioinformatics to investigate APOBEC3A expression and outcomes using The Cancer Genome Atlas (TCGA)-cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) dataset, GTEx, and GSE7803. Immunohistochemistry was then used to identify APOBEC3A's expression pattern. We performed Cell Counting Kit-8, wound-healing, Transwell, and flow cytometry assays to measure proliferation, migration, invasion, and apoptosis, respectively, using the SiHa and HeLa cell lines transfected with APOBEC3A. BALB/c nude mice were used to investigate the effects of APOBEC3A in vivo. The phosphorylated gamma-H2AX staining assay was applied to measure DNA damage. RNA sequencing (RNA-Seq) was applied to explore APOBEC3A-related signaling pathways. Results: APOBEC3A was more significantly expressed in cancer tissues than in adjacent normal tissues. Higher expression of APOBEC3A was associated with better outcomes in TCGA-CESC and GTEx. Immunohistochemistry showed that the expression of APOBEC3A was significantly higher in cancer tissues than in normal tissues. Transfection experiments showed that APOBEC3A inhibited proliferation, upregulated S-phase cells, inhibited migration and invasion, induced DNA damage, and promoted apoptosis. Overexpression of APOBEC3A inhibited tumor formation in the mouse model. RNA-seq analysis showed that ectopic expression of APOBEC3A inhibited several cancer-associated signaling pathways. Conclusions: APOBEC3A is significantly upregulated in cervical cancer, and higher expression of APOBEC3A is associated with better outcomes. APOBEC3A is a tumor suppressor whose overexpression induces apoptosis in cervical cancer.