Introduction: Gastric Cancer (GC) is among the leading causes of cancer-related death worldwide. This scenario is driven not only by late diagnosis, but also by the limitations of existing therapies. Conventional chemotherapy is associated with high systemic toxicity, compromising patients’ quality of life and, in some cases, limiting treatment continuity. Doxorubicin, for example, is a topoisomerase II inhibitor widely applied for various tumors, but its usage is often restricted due to severe side effects. Given these limitations, the development of safer, more selective and more effective therapies is urgently needed. In this context, natural products have emerged as promising sources of new antineoplastic molecules. Among them, geopropolis —a compound produced by stingless bees from plant resins, enzymatic secretions and soil or clay particles— is notable for its antioxidant, anti-inflammatory and antiproliferative effects, making it a promising alternative for new therapeutic approaches. Objectives: This study sought to assess the individual and combined effects of a geopropolis extract and doxorubicin in a GC cell model. Methods: For that, AGP01 cells (Metastatic Gastric Adenocarcinoma) and HEK-293 cells (Non-neoplastic Human Embryonic Kidney) were subjected to the MTT cell viability assay for 72 hours, with concentrations ranging from 100 to 1.56 ?g/mL of the ethanolic geopropolis extract from the species Melipona seminigra pernigra (UBR) and ranging from 8 to 0.125 ?M of doxorubicin, applied independently. Subsequently, the mean inhibitory concentration (IC50) of the extract was combined with the dosage curve of doxorubicin to investigate potential combination effects. Complementary analyses were also performed to evaluate the cell death pattern (Annexin V/PI), reactive oxygen species (ROS) production (DCFH-DA), and DNA damage (?H2AX), using both isolated and combined IC50 values. Results: We observed that the geopropolis extract reduced AGP01 cell viability with an IC50 of 8.3?g/mL, while doxorubicin showed an IC50 of 9?M. In HEK-293 cells, the geopropolis extract demonstrated lower toxicity (IC50 = 22.2 ?g/mL), whereas doxorubicin was notably toxic (IC50 = 0.6 ?M), indicating high selectivity for the extract and low selectivity for the chemotherapy. The combination of both compounds led to a more pronounced reduction in cell viability, even at lower doxorubicin concentrations, suggesting a synergistic or additive effect. Both compounds individually induced apoptosis, and this effect persisted with the combination. When isolated, neither treatment influenced ROS levels, but their combination resulted in a significant decrease in ROS production, indicating potential antioxidant activity. DNA damage was accentuated with isolated doxorubicin treatment, while combination with the geopropolis extract mitigated this effect. Conclusion: In summary, the geopropolis extract demonstrated selective cytotoxic activity. When combined with doxorubicin, it enhanced treatment effectiveness, maintained apoptosis induction, reduced ROS levels and mitigated the genotoxicity caused by doxorubicin therapy. These results suggest that geopropolis may act as a possible adjunct agent, raising the efficacy and reducing the side effects of doxorubicin. However, further studies are needed to clarify its mechanisms of action and validate its applicability.
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/
Complete tool for submission, evaluation and publication of proceedings for scientific events.
