Introduction: Gastric cancer (GC) is still one of the main causes of mortality in the world and represents a major challenge for public health. Given its heterogeneity, it is necessary to identify therapeutic and diagnostic biomarkers. The CDH17 protein is frequently co-expressed with CDX2, a transcription factor that is essential for the development and maintenance of the intestinal epithelium. In normal tissues, CDH17 and CDX2 are restricted to the intestine and are absent in healthy gastric epithelium. However, in the GC, CDX2 acts by regulating the transcription of intestinal genes, including CDH17, and contributes to the phenotypic reprogramming of gastric cells. Given the importance of cadherins in cell morphogenesis and differentiation, it is believed that CDH17 may mediate the effects of CDX2 in inducing an intestinal phenotype, contributing to carcinogenesis. In this context, CDX2 and CDH17 are potential diagnostic and therapeutic targets in gastric cancer. Objectives: To evaluate the expression of the CDH17 and CDX2 genes in patients with gastric adenocarcinoma in the state of Pará. Methods: This study was approved by the Research Ethics Committee (CAAE nº 47580121.9.0000.5634). 79 samples of GC tissue and adjacent tissue (ADJ) were collected for total RNA sequencing. The readings were processed with FastQC and Trimmomatic, aligned with Salmon and normalized in TPM. Comparative analyses of gene expression were carried out using the Wilcoxon test, considering p < 0.05 to be significant. Statistical analyses and the generation of expression graphs were carried out using R software. Gene-gene interaction was investigated using the STRING platform. Results: Differential expression (DE) analyses considering the intestinal and diffuse subtypes of GC, as well as H. pylori infection status (negative or positive), revealed a statistically significant DE for the CDH17 (p = 0.00414) and CDX2 (p = 0.02167) genes between GC and ADJ tissues, with higher expression in tumors. In relation to H. pylori status, there was a significant difference in CDH17 expression (p = 0.01755), which was higher in negative individuals. CDX2 had a tendency towards increased expression in negative individuals, but it was not statistically significant (p = 0.05766). Network analysis using the STRING platform showed a functional association between CDH17 and CDX2 through co-expression. Conclusion: The CDH17 and CDX2 genes are more expressed in tumor tissue when compared to adjacent tissue, indicating their potential as a biomarker in GC. Although the inflammation caused by H. pylori favors intestinal metaplasia, an important factor for the activation of these genes, the expression of CDH17 shows significant variation according to H. pylori infection status, being higher in negative individuals. On the other hand, CDX2 showed no statistically significant difference, only a trend. This apparent contradiction may be explained by the reduction in H. pylori colonization in advanced stages of gastric cancer, when intestinal reprogramming mediated by CDX2 and CDH17 is already established. Finally, the functional analysis reinforces the interaction between the two genes, suggesting the co-expression and a collaborative role in gastric tumorigenesis.
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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