Seed integration - a novel mechanism triggering cancer.

Bladder cancer in young women is rare and typically aggressive, with advanced cases linked to significant genomic instability. A recent case report by Catanzaro et al. 2025 described a 31-year-old woman developing stage IV bladder cancer within 12 months of receiving three doses of the Moderna modRNA COVID-19 vaccine. This study investigated potential molecular links between modRNA vaccination and oncogenesis, focusing on a 20 bp fragment from the Pfizer BNT162b2 plasmid Spike protein ORF (bases 5905–5924) integrated into chromosome 19 (chr19:55,482,637–55,482,674) of the patient’s genome. Since multi-omic profiling revealed dysregulated oncogenic drivers (e.g., KRAS, PIK3CA) and impaired DNA repair mechanisms (e.g., ATM, MSH2) associated with the integrated fragment, we asked, if it is possible that such integrated fragment could carry sequence motif, enabling epigenetic mechanism of pro-oncogenic dysregulation. Using RNA22 v2 in this preliminary in silico analysis, we identified interactions between integrated 20 bp long fragment and tumor-suppressive hsa-let-7a-5p, hsa-miR-15a-5 microRNAs, indicating a possible “sponging” effect that could disrupt miRNA-mediated oncogene suppression. These findings further underscore the urgent need for rigorous “seed-proofreading” in all mRNA-based therapeutics to minimize unintended epigenetic effects, including microRNA dysregulation, inflammation, and cancer.