BRCA Mutations Shape Immune Landscapes in Ovarian Cancer, Spatial Study Finds

High-grade serous ovarian cancer (HGSOC) is marked by extensive heterogeneity both within tumors and between patients, which helps explain why treatments work differently in different women. A new multi-omics study has now mapped how BRCA mutation status appears to influence the immune landscape of these tumors, revealing distinct spatial immune transcriptional patterns rather than a wholesale restructuring of tumor architecture.

The research team integrated whole exome sequencing, total RNA sequencing, and spatial transcriptomics to profile tumors from patients with BRCA-mutated (BRCA-MT) and non-BRCA-mutated (BRCA-WT) HGSOC. While mutations in BRCA1/2 are already known to correlate with improved responses to DNA-damaging agents, how this genotype shapes the tumor immune microenvironment has remained poorly understood. Bulk transcriptomic analysis pointed to a broadly more pro-inflammatory milieu in BRCA-MT tumors, but the spatially resolved methods showed how these differences manifest within specific tissue architectures.

Integrated clustering revealed recurrent spatial transcriptional states shared across genotypes. Among them, the researchers identified a transcriptionally distinct immune-enriched region, labeled IC7, characterized by low tumor purity, active interferon signaling, and antigen-presentation programs. Reference-based RCTD deconvolution provided independent computational support that IC7 was enriched for T and natural killer cells as well as dendritic cells compared with other regions.

The functional state of IC7 proved highly dependent on BRCA status. Tumors carrying BRCA mutations showed stronger enrichment of interferon-alpha and interferon-gamma responses and inflammatory signaling within these immune-rich regions than tumors without such mutations. Exploratory CellChat analysis further suggested genotype-associated differences in predicted immune-related signaling between cell populations.

Beyond the immune compartment, the study identified a conserved structural interface between a cancer-associated fibroblast-like region (IC3) and a macrophage-rich region (IC4), accompanied by a predicted CXCL12–CXCR4 chemokine recruitment axis, hinting at a mechanism by which these spatially adjacent compartments may communicate.

Taken together, the findings support a model in which BRCA mutation status is associated with functional differences operating within broadly conserved spatial regions, rather than extensive reorganization of the tumor’s overall spatial architecture. The authors emphasize that this spatially resolved framework identifies BRCA-associated immune transcriptional patterns in HGSOC and provides a foundation for future mechanistic validation, rather than establishing clinical utility on its own.

Subject of Research: Spatial multi-omics analysis of BRCA-associated immune patterns in high-grade serous ovarian cancer

Article Title: Multi-omics analysis of high-grade serous ovarian cancers reveals heterogeneity and distinct immunological patterns based upon clinico-genomic status

Article References: Qian, J., Bassiouni, R., Jin, Y., Rajpara, S., Neuman, M., Khetan, V. U., Salhia, B., Craig, D. W., Carlson, J. W., Roman, L. D., & Carpten, J. D. (2026). Multi-omics analysis of high-grade serous ovarian cancers reveals heterogeneity and distinct immunological patterns based upon clinico-genomic status. PLOS Genetics, 22(10), e1012355. https://doi.org/10.1371/journal.pgen.1012355

Image Credits: AI Generated

DOI: 10.1371/journal.pgen.1012355

Keywords: high-grade serous ovarian cancer, BRCA mutations, tumor immune microenvironment, spatial transcriptomics, whole exome sequencing, RNA sequencing, interferon signaling, tumor heterogeneity, cancer-associated fibroblasts, macrophages, immunogenomics, multi-omics