مقالات پذیرفته شده در هشتمین کنگره بین المللی زیست پزشکی
Advancing Breast Cancer Research: The Role of BRCA1 Mutations and Organoid Models
Advancing Breast Cancer Research: The Role of BRCA1 Mutations and Organoid Models
Ali Mahmoodi,1Faramarz Khosravi,2,*
1. Bachelor’s student, Microbiology group, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran 2. Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
Introduction: Breast cancer holds a significant status among the most widespread malignancies globally, with mutations in the BRCA1 gene representing a pivotal element in its pathogenesis and progression. The role of the BRCA1 gene is significant in addressing DNA double-strand breaks, using homologous recombination as its operational technique. Mutations that impair BRCA1 disrupt this vital repair process, resulting in genomic instability and an increased vulnerability to cancer. Conventional models utilized to investigate BRCA1 mutations possess inherent limitations, thereby necessitating the development of more precise and representative experimental frameworks. Tumor organoids obtained from patients (PDTOs) signify a creative and encouraging pathway for investigating cancer. These three-dimensional cultures preserve the histological and genetic attributes of the parent tumors, thereby furnishing a more physiologically relevant environment for exploring cancer biology and evaluating therapeutic interventions.
Methods: The establishment and maintenance of organoids involved the procurement of fresh tissue specimens from breast cancer patients harboring BRCA1 mutations. These specimens underwent enzymatic digestion and mechanical dissociation to yield cell suspensions, which were subsequently encapsulated in Matrigel and cultured under meticulously formulated media conditions. The organoids were systematically monitored and passaged to guarantee their continued growth and viability. The study also integrated a variety of assays aimed at assessing the responses of organoids to therapeutic treatments. Drug dose-response assays were performed to determine the efficacy of diverse therapeutic agents. We engaged in the examination of the expression rates of crucial proteins tied to DNA repair operations and cell cycle oversight by employing immunohistochemical evaluations along with Western blotting procedures. The implementation of EdU incorporation assays, alongside RNA extraction and subsequent RT-qPCR, was crucial for the investigation of cellular proliferation and shifts in gene expression. Live cell imaging employing specific peptides enabled the elucidation of protein interactions within the organoids.
Results: The organoid models derived from BRCA1-mutated breast cancer tissues displayed genetic and phenotypic attributes that closely resembled those of the original tumors, thereby affirming their applicability as a representative model for this cancer subtype. The use of PARP inhibitors, for instance talazoparib, in organoids that have BRCA1 mutations caused a notable rise in DNA damage and cytotoxicity when compared to the wild-type variants. Merging PARP inhibitors with substances that damage DNA, like temozolomide, has produced a significantly better interaction, illustrating their synergistic relationship. The investigation further demonstrated that elevated levels of mutant p53 (mtp53) and PARP expression were associated with heightened sensitivity to the combined treatment regimen. This dual biomarker strategy holds significant potential for predicting and optimizing treatment outcomes for patients afflicted by BRCA1 mutations.
Conclusion: The employment of organoid models derived from breast cancer tissues characterized by BRCA1 mutations signifies a significant advancement in the investigation of the underlying mechanisms that drive tumorigenesis and the evaluation of novel therapeutic interventions. These models retain the intricate architecture and genetic diversity of the original tumors, thereby providing a more accurate representation when compared to traditional cell lines. The findings of the investigation underscore the potential advantages of a synergistic methodology that incorporates PARP inhibitors alongside DNA-damaging therapies to enhance patient management for individuals with BRCA1 mutations. Future research initiatives should focus on the enhancement of organoid models to encompass a wider array of genetic backgrounds and the exploration of additional combinatorial therapies to further improve patient outcomes.