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MicroRNA Expression Links Transportation Environmental Burden to Late-Stage Triple-Negative Breast Cancer
Nubaira Rizvi1, Amjila Bam1, Xiao-Cheng Wu2
1Department of Biostatistics and Data Science, School of Public Health, LSU Health-New Orleans, New Orleans, LA 70112-2223, USA.
Genes
|July 28, 2026
Summary
Transportation burden is linked to later-stage triple-negative breast cancer (TNBC) diagnosis. Tumor microRNAs (miRNAs) mediate this association, revealing molecular pathways connecting environmental exposures to cancer disparities.
Area of Science:
- Environmental Health
- Molecular Biology
- Oncology
Background:
- Triple-negative breast cancer (TNBC) is aggressive and shows diagnostic stage disparities.
- Transportation-related environmental exposures are potential health risks, but biological links to cancer are unclear.
- Tumor microRNAs (miRNAs) regulate gene expression and can influence cancer progression.
Purpose of the Study:
- To investigate if tumor miRNAs mediate the association between transportation burden and TNBC stage at diagnosis.
- To identify specific miRNAs and biological pathways involved in this environmental-cancer link.
Main Methods:
- Analysis of 434 TNBC cases from the Louisiana Tumor Registry (2009-2019).
- Quantification of transportation burden based on proximity to major transportation routes.
- High-throughput sequencing for miRNA expression analysis and mediation analysis.
- KEGG pathway enrichment analysis to identify downstream biological pathways.
Main Results:
- Increased transportation burden rank was significantly associated with higher odds of late-stage TNBC diagnosis, even after adjusting for covariates (OR=1.09, p=0.021).
- Five miRNAs (hsa-let-7c-5p, hsa-let-7b-5p, hsa-miR-30a-3p, hsa-miR-92a-3p, hsa-miR-151a-3p) significantly mediated the association.
- Joint mediation analysis indicated complete mediation (indirect effect=0.324, p=0.027), with hsa-let-7c-5p as the primary independent mediator.
- Enriched pathways included MAPK, PI3K-Akt, Wnt, and p53 signaling.
Conclusions:
- This study identifies specific miRNAs and molecular pathways (MAPK, PI3K-Akt, Wnt, p53) linking transportation-related environmental exposures to TNBC progression.
- Dysregulation of specific miRNAs plays a crucial role in mediating the effect of transportation burden on TNBC stage.
- Integrating environmental exposure data with tumor biology advances understanding of how the built environment contributes to cancer disparities.
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