Introduction: Gastric cancer is among the malignancies with the highest mortality rates, particularly in advanced stages. Loss of epithelial polarity, often due to altered expression of tight junction proteins such as claudins, plays a key role in tumor progression. Claudin 18.2 (CLDN18.2) has gained attention for its selective expression in gastric mucosa. Its presence in tumors and absence in most normal tissues make it a promising target for diagnostic and therapeutic strategies in oncology. Objectives To obtain, characterize, and validate an IgY antibody specifically targeting claudin 18.2 (CLDN18.2) through immunization with the synthetic PCNI peptide, evaluating its affinity and expression in gastric adenocarcinoma cell lines, with a focus on diagnostic and therapeutic applications in gastric cancer. Methods: Adult White Leghorn hens were immunized with the synthetic peptide PCNI, corresponding to the extracellular loop of CLDN18.2, combined with Montanide adjuvant, in three doses administered on days 0, 14, and 21 (CEUA Ethics Protocol No. 1326191222). Eggs were collected daily before and after immunization. IgY antibodies were extracted from the yolks, purified using Amicon® filters, and quantified. SDS-PAGE assessed protein integrity, and immune response was evaluated by Dot Blot, Western Blot, and ELISA. In the ELISA assay, the affinity of the IgY anti-CLDN18.2 was compared to a commercial polyclonal anti-CLDN18 antibody used as a positive control. The specificity of the antibody was tested by immunofluorescence in three gastric cancer cell lines: MKN45, ACP03, and AGP01. Statistical analysis was performed using ANOVA followed by Tukey’s post hoc test in GraphPad Prism 5.5 and R software (version 4.4), considering p ? 0.05 as statistically significant. Results: Purification using Amicon columns resulted in a recovery rate above 60%, while maintaining the structural integrity of the antibody, as confirmed by SDS-PAGE, which revealed clear bands corresponding to the light (~27 kDa) and heavy (~67 kDa) chains. Dot Blot analysis demonstrated a progressive increase in the immune response over the immunization period. The specificity and integrity of the IgY antibody were confirmed by Western Blot. ELISA assays indicated a strong affinity of the anti-claudin 18.2 IgY antibody for the PCNI peptide, which corresponds to the extracellular domain of the protein. Notably, the concentrations of 1395 ug/mL and 2739 ?g/mL showed statistically significant differences compared to the positive control (R = 0.98; p < 0.0001). The expression and specificity of the new antibody were confirmed in vitro by immunofluorescence, showing selective staining in all three tested cell lines (MKN45, ACP03, and AGP01) and no signal in the negative controls. Compared to the commercial polyclonal anti-CLDN18 antibody, the produced anti-claudin 18.2 IgY antibody exhibited equivalent reactivity, validating its functionality in both metastatic gastric cancer cells (MKN45 and AGP01) and in primary tumor cells (ACP03). Conclusion: This study demonstrated the feasibility of producing IgY antibodies against CLDN18.2 in a scalable and cost-effective way. This is the first reported production of an IgY antibody targeting the CLDN18.2 isoform. The antibody showed high specificity, highlighting its potential for diagnostic and therapeutic applications in gastric cancer.
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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