Presentation Type
Poster
Presentation Type
Submission
Keywords
Breast Cancer, Microbiology, Biomarkers
Department
Biology
Major
Biology
Abstract
Breast cancer (BC) affects 1 in 8 women and roughly 50% of breast cancers cannot be explained by environmental or genetic factors. There is growing evidence of the role of the human breast microbiome in breast cancer, but the mechanisms guiding this role are not well understood. The co-evolution of the human microbiome with the immune system represents an interaction between host and microbiome that is understudied with regard to breast cancer pathogenesis. We hypothesized that immune genetic variation is associated with altered abundance patterns of bacterial taxa in BC. We conducted 30X whole genome sequencing on a sample of 45 women who donated 60 tissues, grouped into four distinct tissue types: healthy (H), pre-diagnostic (PD), tumor (T), and adjacent normal (AN), to the Susan G. Komen and Indiana University Simon Comprehensive Cancer Center Tissue Banks. We filtered variants for inclusion in our analysis by quality score, variant impact, relation to immune function, and association with the PD, AN, and T tissues (precancerous and cancerous tissues). We used MaAsLin2 to associate alternate allele frequencies (AAF) and genotypes with amplicon sequence variant (ASV) abundances from breast bacteria previously identified as associated with BC (Hoskinson et al. mSystems, 2022). 13 variants were significantly associated with ASV abundances. The top 4 variants with the highest number of ASV associations with either AAF or genotype were AKR1C3 (genotype: 9 ASVs, AAF: 8 ASVs), ARG1 (genotype: 8 ASVs, AAF: 2 ASVs), CFHR3 (genotype: 13 ASVs, AAF: 4 ASVs) and PRAM1 (genotype: 27 ASVs, AAF: 16 ASVs). Pseudomonas ASVs were the top ASVs associated with these genes (24 total associations). These results suggest interaction of specific breast bacterial taxa with immune variants in BC. We aim to analyze the functional metagenome in association with immune variants to inform how these taxa may influence host immune variation.
Faculty Mentor
Dr. Leah Stiemsma
Funding Source or Research Program
Summer Undergraduate Research Program
Location
Waves Cafeteria
Start Date
10-4-2026 1:00 PM
End Date
10-4-2026 2:00 PM
Included in
Associations between the human breast microbiome and immune genes in breast cancer
Waves Cafeteria
Breast cancer (BC) affects 1 in 8 women and roughly 50% of breast cancers cannot be explained by environmental or genetic factors. There is growing evidence of the role of the human breast microbiome in breast cancer, but the mechanisms guiding this role are not well understood. The co-evolution of the human microbiome with the immune system represents an interaction between host and microbiome that is understudied with regard to breast cancer pathogenesis. We hypothesized that immune genetic variation is associated with altered abundance patterns of bacterial taxa in BC. We conducted 30X whole genome sequencing on a sample of 45 women who donated 60 tissues, grouped into four distinct tissue types: healthy (H), pre-diagnostic (PD), tumor (T), and adjacent normal (AN), to the Susan G. Komen and Indiana University Simon Comprehensive Cancer Center Tissue Banks. We filtered variants for inclusion in our analysis by quality score, variant impact, relation to immune function, and association with the PD, AN, and T tissues (precancerous and cancerous tissues). We used MaAsLin2 to associate alternate allele frequencies (AAF) and genotypes with amplicon sequence variant (ASV) abundances from breast bacteria previously identified as associated with BC (Hoskinson et al. mSystems, 2022). 13 variants were significantly associated with ASV abundances. The top 4 variants with the highest number of ASV associations with either AAF or genotype were AKR1C3 (genotype: 9 ASVs, AAF: 8 ASVs), ARG1 (genotype: 8 ASVs, AAF: 2 ASVs), CFHR3 (genotype: 13 ASVs, AAF: 4 ASVs) and PRAM1 (genotype: 27 ASVs, AAF: 16 ASVs). Pseudomonas ASVs were the top ASVs associated with these genes (24 total associations). These results suggest interaction of specific breast bacterial taxa with immune variants in BC. We aim to analyze the functional metagenome in association with immune variants to inform how these taxa may influence host immune variation.