Browsing by Author "Sánchez, Carolina"

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    Beyond tobacco: genomic disparities in lung cancer between smokers and never-smokers
    (Springer Nature, 2024) Garrido, Javiera; Bernal, Yanara; González, Evelin; Blanco, Alejandro; Sepúlveda-Hermosilla, Gonzalo; Freire, Matías; Oróstica, Karen; Rivas, Solange; Marcelain, Katherine; Owen, Gareth Ivor; Ibáñez Cáceres, Carolina; Corvalán Rodríguez, Alejandro; Garrido, Marcelo; Assar, Rodrigo; Lizana, Rodrigo; Cáceres-Molina, Javier; Ampuero, Diego; Ramos, Liliana; Pérez, Paola; Aren, Osvaldo; Chernilo, Sara; Fernández, Cristina; Spencer, María L.; Aguila, Jacqueline F.; Dossetto, Giuliano B.; Olea, Mónica A.; Rasse, Germán; Sánchez, Carolina; Amorim, Maria Galli de; Bartelli, Thais F.; Nunes, Diana N.; Dias-Neto, Emmanuel; Freitas, Helano C.; Armisén, Ricardo
    Tobacco use is one of the main risk factors for Lung Cancer (LC) development. However, about 10–20% of those diagnosed with the disease are never-smokers. For Non-Small Cell Lung Cancer (NSCLC) there are clear differences in both the clinical presentation and the tumor genomic profiles between smokers and never-smokers. For example, the Lung Adenocarcinoma (LUAD) histological subtype in never-smokers is predominately found in young women of European, North American, and Asian descent. While the clinical presentation and tumor genomic profiles of smokers have been widely examined, never-smokers are usually underrepresented, especially those of a Latin American (LA) background. In this work, we characterize, for the first time, the difference in the genomic profiles between smokers and never-smokers LC patients from Chile. Methods We conduct a comparison by smoking status in the frequencies of genomic alterations (GAs) including somatic mutations and structural variants (fusions) in a total of 10 clinically relevant genes, including the eight most common actionable genes for LC (EGFR, KRAS, ALK, MET, BRAF, RET, ERBB2, and ROS1) and two established driver genes for malignancies other than LC (PIK3CA and MAP2K1). Study participants were grouped as either smokers (current and former, n = 473) or never-smokers (n = 200) according to self-report tobacco use at enrollment. Results Our findings indicate a higher overall GA frequency for never-smokers compared to smokers (58 vs. 45.7, p-value < 0.01) with the genes EGFR, KRAS, and PIK3CA displaying the highest prevalence while ERBB2, RET, and ROS1 the lowest. Never-smokers present higher frequencies in seven out of the 10 genes; however, smokers harbor a more complex genomic profile. The clearest differences between groups are seen for EGFR (15.6 vs. 21.5, p-value: < 0.01), PIK3CA (6.8 vs 9.5) and ALK (3.2 vs 7.5) in favor of never-smokers, and KRAS (16.3 vs. 11.5) and MAP2K1 (6.6 vs. 3.5) in favor of smokers. Alterations in these genes are comprised almost exclusively by somatic mutations in EGFR and mainly by fusions in ALK, and only by mutations in PIK3CA, KRAS and MAP2K1. Conclusions We found clear differences in the genomic landscape by smoking status in LUAD patients from Chile, with potential implications for clinical management in these limited-resource settings.
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    Differentially Expressed Genes and Signaling Pathways Potentially Involved in Primary Resistance to Chemo-Immunotherapy in Advanced-Stage Gastric Cancer Patients
    (MDPI, 2023) Pinto, Mauricio P.; Bravo, María Loreto; Córdova Delgado, Miguel; Hill, Charlotte N.; Muñoz Medel, Matías; Retamal, Ignacio N.; Fernández, M. Fernanda; Sánchez, Carolina; Sáez, Mauricio A.; Morales Pison, Sebastián; García Bloj, Benjamín; Garrido, Marcelo; Latapiat, Verónica; Martín, Alberto J.M.; Fernández Ramírez, Ricardo; Owen Gareth Ivor
    Recently, the combination of chemotherapy plus nivolumab (chemo-immunotherapy) has become the standard of care for advanced-stage gastric cancer (GC) patients. However, despite its efficacy, up to 40% of patients do not respond to these treatments. Our study sought to identify variations in gene expression associated with primary resistance to chemo-immunotherapy. Diagnostic endoscopic biopsies were retrospectively obtained from advanced GC patients previously categorized as responders (R) or non-responders (NR). Thirty-four tumor biopsies (R: n = 16, NR: n = 18) were analyzed by 3? massive analysis of cDNA ends (3?MACE). We found >30 differentially expressed genes between R and NRs. Subsequent pathway enrichment analyses demonstrated that angiogenesis and the Wnt-?-catenin signaling pathway were enriched in NRs. Concomitantly, we performed next generation sequencing (NGS) analyses in a subset of four NR patients that confirmed alterations in genes that belonged to the Wnt/?-catenin and the phosphoinositide 3-kinase (PI3K) pathways. We speculate that angiogenesis, the Wnt, and the PI3K pathways might offer actionable targets. We also discuss therapeutic alternatives for chemo-immunotherapy-resistant advanced-stage GC patients.