Introduction: Mitochondrial DNA (mtDNA) encodes proteins involved in the regulation and homeostasis of cellular metabolism. Alterations in mtDNA regions may lead to metabolic changes and promote tumor growth in various types of malignant neoplasms, including breast cancer. In this context, variants in the ND5 region, which encodes proteins of Complex I of the respiratory chain, can impair mitochondrial function, contributing to cell proliferation and resistance to apoptosis. Objectives: To investigate single nucleotide variations (SNVs) in the ND5 region in breast tumor samples and associate them with the clinical characteristics of patients from the Pará population. Methods: A total of 33 breast tumor samples and 21 control samples were analyzed. This study was approved by the Ethics Committee of the involved institutions. DNA was extracted using a commercial kit, amplified by conventional PCR, and sequenced using the Sanger method. The sequences were aligned with the GenBank reference using BioEdit, and the identified SNVs were analyzed using the MITOMAP, mtDB, and ClinVar databases. Associations between SNVs and clinical data were assessed using statistical tests in BioEstat 5.0 software, with statistical significance set at p ? 0.05. Putative structural alterations in the protein were analyzed using NPS@ and ProtParam, and STRING software was used to predict ND5 protein interactions. Results: We identified 25 SNVs in the tumor group and 14 SNVs in the control samples. None of the variants showed a statistically significant association with molecular subtypes or clinical data. Among the identified SNVs, C12705T (I123M) was the most frequent in both tumor (36.7%) and control samples (34.8%). Although this alteration is not listed in ClinVar, previous studies have reported its presence in various pathological conditions, including neurological disorders, respiratory diseases, and cardiac conditions. Additionally, other relevant variants were observed: A12437W (H34R – 5.8%) and G12454A (V40I – 4.4%), considered likely benign and benign, respectively, but previously associated with kidney diseases, liver aging, and tumors such as breast and prostate cancer. These three SNVs result in subtle alterations to the protein structure and may also affect its function. It was also noted that the ND5 protein is part of a broad interaction network, including other proteins of the mitochondrial respiratory chain, such as CO1 and ND1. Conclusion: The results indicate that alterations in the ND5 region are frequent in breast cancer and can lead to structural modifications in the resulting protein. Although no correlations between the SNVs and clinicopathological data were observed, possibly due to the small sample size, the fact that alterations in Complex I of the respiratory chain may lead to mitochondrial dysfunction and cellular oxidative stress underscores the importance of further studies focused on mtDNA. Considering the above, further studies are essential to better understand the functional role of the observed SNVs in the deregulation of cellular energy metabolism.
It is with great enthusiasm that we present the Annals of the Oncology International Symposium 2025, an event that continues to solidify its significance in the oncology landscape of northern Brazil. Held in Belém, Pará, Oncology 2025 centered around the theme "The cancer control challenge: better knowing it to best facing it," dedicating itself to exploring the latest frontiers in cancer treatment and prevention.
This year, the symposium provided a deep dive into the essential role of knowledge in the fight against cancer, presenting new perspectives and scientific advancements across various areas of oncology. Renowned global experts gathered to share their most recent research and innovative approaches, offering participants a comprehensive view of the challenges faced by healthcare professionals and patients worldwide.
Presentations and discussions during the event focused on critical topics such as the use of new technologies, advancements in personalized therapies, and more effective prevention strategies. Additionally, particular attention was given to the unique challenges faced by the Amazon region, with efforts aimed at developing region-specific solutions to meet local needs.
Beyond being a high-caliber academic event, Oncology 2025 stood out as a moment for integration and professional networking, with the warm hospitality of the city of Belém offering participants a unique experience. This event became a platform for exchanging ideas, where science, culture, and humanity came together in pursuit of a common goal: to improve cancer control both in Brazil and globally.
This collection of abstracts and articles presented during the event reflects the ongoing dedication to research and the development of innovative solutions, highlighting the importance of collaboration and shared knowledge in the fight against cancer.
General Submission Guidelines:
The presenting author, who does not have to be the first author, must be registered for Oncology 2025.
Each abstract may have up to 10 authors, including the main author and co-authors.
Only original, unpublished work will be accepted.
Submissions must be related to oncology. However, project descriptions, work proposals, experience reports, and literature reviews will not be considered.
Clinical case reports are allowed, provided the abstract addresses scientific questions, details clinical observations, and includes primary scientific data.
The abstract must be written in English, but presentations may be given in Portuguese.
Abstracts must be between 300 and 500 words.
Comissão Organizadora
Comissão Científica
See Annals of Oncology 2023 at:
https://www.even3.com.br/anais/oncology-2023-international-symposium/
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