Mutational landscape of gastric adenocarcinoma in Latin America: A genetic approach for precision medicine

Germline Genetic Variants in Cancer Predisposition Genes in Patients From Latin America and the Caribbean

The importance of having region-specific data when planning health interventions has become evident in recent years. Nonetheless, several world regions, including Latin America and the Caribbean (LAC), still face significant challenges. These regions need to develop strategies specifically designed to consider the inherent characteristics of their population composite and sociodemographic characteristics. More than 20% of the global cancer incidence arises in LAC. Yet, treatment, prevention, and follow-up guidelines in the area are frequently based on studies that mainly include patients from North America, Europe, and Asia. As personalized approaches become ubiquitous in medical practice, the amount of information emerging from LAC has risen considerably. In this review, we seek to present a comprehensive summary of the frequency of germline genetic variants in hereditary cancer syndromes in patients from LAC. The data highlight relevant differences in variants associated with LAC patients, including founder and recurrent variants, while showcasing potential features that might be relevant in oncology practices.

MBNL3 Acts as a Target of miR-302e to Facilitate Cell Proliferation, Invasion and Angiogenesis of Gastric Adenocarcinoma via AKT/VEGFA Pathway

Gastric adenocarcinoma (GAC) is a common, malignant type of tumor in human, and is accompanied with higher mortality. Muscleblind-like 3 (MBNL3) was found to be a pivotal participator in aggravating this cancer's progression. However, the regulatory effects of MBNL3 on GAC development have not been investigated. We therefore sought to study the functions of MBNL3 in GAC progression. In this study, it was demonstrated that MBNL3 exhibited higher expression, and GAC patients with higher MBNL3 expression had poor prognosis. Overexpression of MBNL3 facilitated, and knockdown of MBNL3 suppressed cell proliferation, invasion, and angiogenesis in GAC. Further experiments showed that miR-302e targets MBNL3. Rescue assays then uncovered that the miR-302e/MBNL3 axis aggravated GAC progression. In addition, MBNL3 activated the AKT/VEGFA pathway, and the suppressive regulatory impacts of MBNL3 knockdown on GAC cell proliferation, invasion, and angiogenesis could be rescued after 740 Y-P treatment. Through in vivo assay, it was proved that MBNL3 accelerated tumor growth in vivo. In conclusion, MBNL3 acted as a target of miR-302e to facilitate cell proliferation, invasion, and angiogenesis of gastric adenocarcinoma through the AKT/VEGFA pathway. Our findings illustrate that MBNL3 may be an available bio-target for GAC treatment.

Somatic Mutational Landscape in Mexican Patients: CDH1 Mutations and chr20q13.33 Amplifications Are Associated with Diffuse-Type Gastric Adenocarcinoma

The Hispanic population, compared with other ethnic groups, presents a more aggressive gastric cancer phenotype with higher frequency of diffuse-type gastric adenocarcinoma (GA); this could be related to the mutational landscape of GA in these patients. Using whole-exome sequencing, we sought to present the mutational landscape of GA from 50 Mexican patients who were treated at The Instituto Nacional de Cancerología from 2019 to 2020. We performed a comprehensive statistical analysis to explore the relationship of the genomic variants and clinical data such as tumor histology and presence of signet-ring cell, H. pylori, and EBV. We describe a potentially different mutational landscape between diffuse and intestinal GA in Mexican patients. Patients with intestinal-type GA tended to present a higher frequency of NOTCH1 mutations, copy number gains in cytobands 13.14, 10q23.33, and 12q25.1, and copy number losses in cytobands 7p12, 14q24.2, and 11q13.1; whereas patients with diffuse-type GA tended to present a high frequency of CDH1 mutations and CNV gains in cytobands 20q13.33 and 22q11.21. This is the first description of a mutational landscape of GA in Mexican patients to better understand tumorigenesis in Hispanic patients and lay the groundwork for discovering potential biomarkers and therapeutic targets.