Sampling, composition, and biological effects of Mexico City airborne particulate matter from multiple periods.

Air pollution is a worldwide environmental problem with an impact on human health. Particulate matter of ten micrometers or less aerodynamic diameter (PM10) as well as its fine fraction (PM2.5) is related to multiple pulmonary diseases. The impact of air pollution in Mexico City, and importantly, particulate matter has been studied and considered as a risk factor for two decades ago. Previous studies have reported the composition of Mexico City particulate matter, as well as the biological effects induced by this material. However, material collected and used in previous studies is a limited resource, and sampling and particle recovery techniques have been improved. In this study, we describe the methods used in our laboratory for Mexico City airborne particulate matter PM10 and PM2.5 sampling, considering the years 2017, 2018 and 2019. We also analyzed the PM10 and PM2.5 samples obtained to determine their composition. Finally, we exposed lung cell line cultures to PM10 and PM2.5 to evaluate the biological effect of the material in terms of cell viability, cell death, inflammatory response, and cytogenetic alterations. Our results showed that PM10 composition includes inorganic, organic and biological compounds, while PM2.5 is a mixture of more enriched organic compounds. PM10 and PM2.5 treatment in lung cells does not significantly impact cell viability/cell death. However, PM10 and PM2.5 increase the secretion levels of IL-6. Moreover, PM10 as well as PM2.5 induce cytogenetic alterations, such as micronuclei, anaphase bridges, trinucleated cells and apoptotic cells in lung cells. Our results update the evidence of the composition and biological effects of Mexico City particulate matter and provide us a reliable basis for future approaches.

Multivariate Prognostic Models for Patients with Stages I and Ii Colon Carcinoma: a Strobe-Compliant Retrospective Cohort Study.

Background: Colorectal cancer is the most frequent gastrointestinal malignancy worldwide. The value of adjuvant treatment is controversial in Stages I and II. Objective: The aim of this study was to construct post-operative prognostic models applicable to patients with stages I-II colon carcinoma (CC). Methods: This is a retrospective cohort study of patients with Stage I-II CC treated over a 25-year period. Exposure was defined as clinical, histopathological, and immunohistochemical factors (including CDX2 and MUC2 expression). Patients were randomly allocated to either a "modeling set" or a "validation set". Factors associated with recurrence, disease-free survival (DFS), and overall survival (OS) were defined in the "modeling set". Their performances were tested in the "validation set". Results: From a total of 556 recruited patients, 339 (61%) were allocated to the "modeling set" and 217 (39%) to the "validation set". Three models explaining recurrence, DFS, and OS were described. Tumor location in the left colon (Hazards ratio [HR] = 1.57; 95% Confidence interval [CI] 0.99-2.48), lymphocyte (HR = 0.46; 96% CI 0.27-0.88) and monocyte (HR = 0.99; 95% CI 0.99-1) counts, neutrophil/platelet ratio (HR = 1.3; 95% CI 0.74-2.3, and HR = 2.3; 95% CI 1.3-4.1; for second and third category, respectively), albumin/monocyte ratio (HR = 0.43; 95% CI 0.21-0.87), and microscopic residual disease after surgery (HR = 8.7; 95% CI 3.1-24) were independently associated with OS. T classification and expression of CDX2 and/or MUC2 were not independently associated with recurrence or prognosis. Conclusion: These models are simple and readily available, and distinguish the risk and prognosis in patients with CC stages I and II; these models require cheaper processes than the use of more sophisticated molecular biology techniques. They may guide either the need for adjuvant therapy versus post-operative surveillance only, as well as aid in the design of clinical trials.

Multivariate Prognostic Models for Patients with Stages I and Ii Colon Carcinoma: a Strobe-Compliant Retrospective Cohort Study

ABSTRACT Background: Colorectal cancer is the most frequent gastrointestinal malignancy worldwide. The value of adjuvant treatment is controversial in Stages I and II. Objective: The aim of this study was to construct post-operative prognostic models applicable to patients with stages I-II colon carcinoma (CC). Methods: This is a retrospective cohort study of patients with Stage I-II CC treated over a 25-year period. Exposure was defined as clinical, histopathological, and immunohistochemical factors (including CDX2 and MUC2 expression). Patients were randomly allocated to either a "modeling set" or a "validation set". Factors associated with recurrence, disease-free survival (DFS), and overall survival (OS) were defined in the "modeling set". Their performances were tested in the "validation set". Results: From a total of 556 recruited patients, 339 (61%) were allocated to the "modeling set" and 217 (39%) to the "validation set". Three models explaining recurrence, DFS, and OS were described. Tumor location in the left colon (Hazards ratio [HR] = 1.57; 95% Confidence interval [CI] 0.99-2.48), lymphocyte (HR = 0.46; 96% CI 0.27-0.88) and monocyte (HR = 0.99; 95% CI 0.99-1) counts, neutrophil/platelet ratio (HR = 1.3; 95% CI 0.74-2.3, and HR = 2.3; 95% CI 1.3-4.1; for second and third category, respectively), albumin/monocyte ratio (HR = 0.43; 95% CI 0.21-0.87), and microscopic residual disease after surgery (HR = 8.7; 95% CI 3.1-24) were independently associated with OS. T classification and expression of CDX2 and/or MUC2 were not independently associated with recurrence or prognosis. Conclusion: These models are simple and readily available, and distinguish the risk and prognosis in patients with CC stages I and II; these models require cheaper processes than the use of more sophisticated molecular biology techniques. They may guide either the need for adjuvant therapy versus post-operative surveillance only, as well as aid in the design of clinical trials.

Ion Channels as Potential Tools for the Diagnosis, Prognosis, and Treatment of HPV-Associated Cancers.

The human papilloma virus (HPV) group comprises approximately 200 genetic types that have a special affinity for epithelial tissues and can vary from producing benign symptoms to developing into complicated pathologies, such as cancer. The HPV replicative cycle affects various cellular and molecular processes, including DNA insertions and methylation and relevant pathways related to pRb and p53, as well as ion channel expression or function. Ion channels are responsible for the flow of ions across cell membranes and play very important roles in human physiology, including the regulation of ion homeostasis, electrical excitability, and cell signaling. However, when ion channel function or expression is altered, the channels can trigger a wide range of channelopathies, including cancer. In consequence, the up- or down-regulation of ion channels in cancer makes them attractive molecular markers for the diagnosis, prognosis, and treatment of the disease. Interestingly, the activity or expression of several ion channels is dysregulated in HPV-associated cancers. Here, we review the status of ion channels and their regulation in HPV-associated cancers and discuss the potential molecular mechanisms involved. Understanding the dynamics of ion channels in these cancers should help to improve early diagnosis, prognosis, and treatment in the benefit of HPV-associated cancer patients.

Current and novel approaches in the pharmacological treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumours worldwide. The mortality-to-incidence ratio is up to 91.6% in many countries, representing the third leading cause of cancer-related deaths. Systemic drugs, including the multikinase inhibitors sorafenib and lenvatinib, are first-line drugs used in HCC treatment. Unfortunately, these therapies are ineffective in most cases due to late diagnosis and the development of tumour resistance. Thus, novel pharmacological alternatives are urgently needed. For instance, immune checkpoint inhibitors have provided new approaches targeting cells of the immune system. Furthermore, monoclonal antibodies against programmed cell death-1 have shown benefits in HCC patients. In addition, drug combinations, including first-line treatment and immunotherapy, as well as drug repurposing, are promising novel therapeutic alternatives. Here, we review the current and novel pharmacological approaches to fight HCC. Preclinical studies, as well as approved and ongoing clinical trials for liver cancer treatment, are discussed. The pharmacological opportunities analysed here should lead to significant improvement in HCC therapy.

Adherence to guidelines on the use of amoxicillin for treatment of ambulatory pneumonia in children younger than 5 years, Colombia, 2017-2019.

Objectives: To determine the level of adherence to clinical guidelines in prescribing amoxicillin to children younger than 5 years with pneumonia in outpatient settings in Colombia from 2017 to 2019, and assess the factors associated with adherence. Methods: This was a cross-sectional study of secondary data from the Colombian Integrated Social Protection Information System database. Adherence was defined as prescription of oral amoxicillin for bacterial and unspecified pneumonia and non-prescription for viral pneumonia. Variables examined included: age (< 1 year, 1-4 years) of child; sex; cause of pneumonia (bacterial, viral, unspecified); region (Andean, Amazonian, Pacific, Caribbean, Insular, Orinoquian); and payment mechanism (without prior authorization, capitation, direct payment, pay per case, pay for event). Results: Of 215 925 cases of community-acquired pneumonia reported during 2017-2019, 64.8% were from the Andean region, 73.9% were bacterial pneumonia and 1.8% were viral pneumonia. Adherence to guidelines was observed in 5.8% of cases: this was highest for children diagnosed with viral (86.0%) compared with bacterial (2.0%) pneumonia. For children diagnosed with bacterial pneumonia, 9.4% were prescribed any antibiotic. A greater proportion of children covered by capitated payments (22.3%) were given treatment consistent with the guidelines compared with payment for event (1.3%). Conclusion: In this first study from Colombia, adherence to guidelines for outpatient treatment of children with bacterial pneumonia was low and was better for viral pneumonia. Further qualitative studies are needed to explore the reasons for this lack of adherence and why bacterial pneumonia was the most commonly reported etiology.

Adherence to guidelines on the use of amoxicillin for treatment of ambulatory pneumonia in children younger than 5 years, Colombia, 2017–2019

[ABSTRACT]. Objectives. To determine the level of adherence to clinical guidelines in prescribing amoxicillin to children younger than 5 years with pneumonia in outpatient settings in Colombia from 2017 to 2019, and assess the factors associated with adherence Methods. This was a cross-sectional study of secondary data from the Colombian Integrated Social Protec- tion Information System database. Adherence was defined as prescription of oral amoxicillin for bacterial and unspecified pneumonia and non-prescription for viral pneumonia. Variables examined included: age (< 1 year, 1–4 years) of child; sex; cause of pneumonia (bacterial, viral, unspecified); region (Andean, Amazonian, Pacific, Caribbean, Insular, Orinoquian); and payment mechanism (without prior authorization, capitation, dir- ect payment, pay per case, pay for event). Results. Of 215 925 cases of community-acquired pneumonia reported during 2017–2019, 64.8% were from the Andean region, 73.9% were bacterial pneumonia and 1.8% were viral pneumonia. Adherence to guide- lines was observed in 5.8% of cases: this was highest for children diagnosed with viral (86.0%) compared with bacterial (2.0%) pneumonia. For children diagnosed with bacterial pneumonia, 9.4% were prescribed any antibiotic. A greater proportion of children covered by capitated payments (22.3%) were given treatment consistent with the guidelines compared with payment for event (1.3%). Conclusion. In this first study from Colombia, adherence to guidelines for outpatient treatment of children with bacterial pneumonia was low and was better for viral pneumonia. Further qualitative studies are needed to explore the reasons for this lack of adherence and why bacterial pneumonia was the most commonly reported etiology.

[RESUMEN]. Objetivos. Determinar el nivel de adherencia a las directrices clínicas al momento de prescribir amoxicilina a menores de 5 años con neumonía en entornos de atención ambulatoria en Colombia entre el 2017 y el 2019, así como evaluar los factores asociados con la adherencia. Métodos. Este fue un estudio transversal de datos secundarios de la base de datos del Sistema Integral de Información de la Protección Social de Colombia. La adherencia se definió como la prescripción de amox- icilina por vía oral para las neumonías bacterianas y no especificadas, y la ausencia de prescripción para las neumonías virales. Las variables examinadas incluyeron: edad (< 1 año, 1 a 4 años); sexo; causa de la neumonía (bacteriana, viral, no especificada); región (andina, amazónica, Pacífico, Caribe, insular, Orinoco); y mecanismo de pago (sin autorización previa, capitación, pago directo, pago por caso, pago por evento). Resultados. De 215 925 casos de neumonía adquirida en la comunidad notificados durante el período 2017- 2019, el 64,8% correspondieron a la región andina, el 73,9% a neumonía bacteriana y el 1,8% a neumonía viral. Se observó la adherencia a las directrices en el 5,8% de los casos: esta cifra fue más alta para la población infantil diagnosticada con neumonía viral (86,0%) que para la diagnosticada con neumonía bacte- riana (2,0%). En el caso de la población infantil diagnosticada con neumonía bacteriana, al 9,4% se le recetó algún antibiótico. La proporción de población infantil cubierta por pagos capitados (22,3%) que recibió un tratamiento en consonancia con las directrices fue mayor que la de la población cubierta por pagos por evento (1,3%). Conclusión. En este primer estudio de Colombia, la adherencia a las directrices sobre el tratamiento ambula- torio de la población infantil con neumonía bacteriana fue bajo, en tanto que resultó superior en el caso de la neumonía viral. Se necesitan más estudios cualitativos para indagar sobre los motivos de esta falta de adher- encia y las razones por las cuales la neumonía bacteriana fue la etiología notificada con mayor frecuencia.

[RESUMO]. Objetivos. Determinar o nível de adesão às diretrizes clínicas para prescrição de amoxicilina em regime ambulatorial para crianças menores de 5 anos com pneumonia na Colômbia, de 2017 a 2019, e avaliar os fatores associados à adesão. Métodos. Estudo transversal de dados secundários do banco de dados do Sistema Integrado de Informação sobre Proteção Social da Colômbia. Definiu-se adesão como prescrição de amoxicilina oral para pneumonia bacteriana e não especificada, e não prescrição para pneumonia viral. As variáveis examinadas incluíram: idade da criança (< 1 ano, 1–4 anos), sexo, etiologia da pneumonia (bacteriana, viral, não especificada), região (Andina, Amazônica, Pacífica, Caribenha, Insular, Orinoco) e mecanismo de pagamento (sem autor- ização prévia, capitação, pagamento direto, pay-per-case, pay-for-event). Resultados. Dos 215.925 casos de pneumonia adquirida na comunidade notificados nos anos 2017-2019, 64,8% ocorreram na região Andina, 73,9% foram pneumonia bacteriana e 1,8% foram pneumonia viral. A adesão às diretrizes foi observada em 5,8% dos casos. Foi maior para crianças com diagnóstico de pneu- monia viral (86,0%) em comparação com pneumonia bacteriana (2,0%). Para as crianças com diagnóstico de pneumonia bacteriana, 9,4% receberam algum antibiótico. Uma proporção maior de crianças cobertas por pagamentos capitados (22,3%) recebeu tratamento compatível com as diretrizes, contra apenas 1,3% no esquema de pay-for-event. Conclusão. Neste primeiro estudo da Colômbia, a adesão às diretrizes para tratamento ambulatorial de cri- anças com pneumonia bacteriana foi baixa, sendo melhor para pneumonia viral. Mais estudos qualitativos são necessários para explorar as razões dessa falta de adesão e por qual motivo a pneumonia bacteriana foi a etiologia mais comumente notificada.

The Road to Malignant Cell Transformation after Particulate Matter Exposure: From Oxidative Stress to Genotoxicity.

In cells, oxidative stress is an imbalance between the production/accumulation of oxidants and the ability of the antioxidant system to detoxify these reactive products. Reactive oxygen species (ROS), cause multiple cellular damages through their interaction with biomolecules such as lipids, proteins, and DNA. Genotoxic damage caused by oxidative stress has become relevant since it can lead to mutation and play a central role in malignant transformation. The evidence describes chronic oxidative stress as an important factor implicated in all stages of the multistep carcinogenic process: initiation, promotion, and progression. In recent years, ambient air pollution by particulate matter (PM) has been cataloged as a cancer risk factor, increasing the incidence of different types of tumors. Epidemiological and toxicological evidence shows how PM-induced oxidative stress could mediate multiple events oriented to carcinogenesis, such as proliferative signaling, evasion of growth suppressors, resistance to cell death, induction of angiogenesis, and activation of invasion/metastasis pathways. In this review, we summarize the findings regarding the involvement of oxidative and genotoxic mechanisms generated by PM in malignant cell transformation. We also discuss the importance of new approaches oriented to studying the development of tumors associated with PM with more accuracy, pursuing the goal of weighing the impact of oxidative stress and genotoxicity as one of the main mechanisms associated with its carcinogenic potential.

Airborne particulate matter (PM10) induces cell invasion through Aryl Hydrocarbon Receptor and Activator Protein 1 (AP-1) pathway deregulation in A549 lung epithelial cells.

BACKGROUND: Particulate matter with an aerodynamic size ≤ 10 µm (PM10) is a risk factor for lung cancer development, mainly because some components are highly toxic. Polycyclic aromatic hydrocarbons (PAHs) are present in PM10, such as benzo[a]pyrene (BaP), which is a well-known genotoxic and carcinogenic compound to humans, capable of activating AP-1 transcription factor family genes through the Aryl Hydrocarbon Receptor (AhR). Because effects of BaP include metalloprotease 9 (MMP-9) activation, cell invasion, and other pathways related to carcinogenesis, we aimed to demonstrate that PM10 (10 µg/cm2) exposure induces the activation of AP-1 family members as well as cell invasion in lung epithelial cells, through AhR pathway. METHODS AND RESULTS: The role of the AhR gene in cells exposed to PM10 (10 µg/cm2) and BaP (1µM) for 48 h was evaluated using AhR-targeted interference siRNA. Then, the AP-1 family members (c-Jun, Jun B, Jun D, Fos B, C-Fos, and Fra-1), the levels/activity of MMP-9, and cell invasion were analyzed. We found that PM10 increased AhR levels and promoted its nuclear localization in A549 treated cells. Also, PM10 and BaP deregulated the activity of AP-1 family members. Moreover, PM10 upregulated the secretion and activity of MMP-9 through AhR, while BaP had no effect. Finally, we found that cell invasion in A549 cells exposed to PM10 and BaP is modulated by AhR. CONCLUSION: Our results demonstrated that PM10 exposure induces upregulation of the c-Jun, Jun B, and Fra-1 activity, the expression/activity of MMP-9, and the cell invasion in lung epithelial cells, effects mediated through the AhR. Also, the Fos B and C-Fos activity were downregulated. In addition, the effects induced by PM10 exposure were like those induced by BaP, which highlights the potentially toxic effects of the PM10 mixture in lung epithelial cells.

Adherence to guidelines on the use of amoxicillin for treatment of ambulatory pneumonia in children younger than 5 years, Colombia, 2017-2019 / Adherencia a las directrices sobre el uso de amoxicilina para el tratamiento ambulatorio de la neumonía en menores de 5 años, Colombia, 2017-2019 / Adesão às diretrizes sobre uso de amoxicilina para tratamento de pneumonia ambulatorial em crianças menores de 5 anos, Colômbia, 2017-2019

ABSTRACT Objectives. To determine the level of adherence to clinical guidelines in prescribing amoxicillin to children younger than 5 years with pneumonia in outpatient settings in Colombia from 2017 to 2019, and assess the factors associated with adherence Methods. This was a cross-sectional study of secondary data from the Colombian Integrated Social Protection Information System database. Adherence was defined as prescription of oral amoxicillin for bacterial and unspecified pneumonia and non-prescription for viral pneumonia. Variables examined included: age (< 1 year, 1-4 years) of child; sex; cause of pneumonia (bacterial, viral, unspecified); region (Andean, Amazonian, Pacific, Caribbean, Insular, Orinoquian); and payment mechanism (without prior authorization, capitation, direct payment, pay per case, pay for event). Results. Of 215 925 cases of community-acquired pneumonia reported during 2017-2019, 64.8% were from the Andean region, 73.9% were bacterial pneumonia and 1.8% were viral pneumonia. Adherence to guidelines was observed in 5.8% of cases: this was highest for children diagnosed with viral (86.0%) compared with bacterial (2.0%) pneumonia. For children diagnosed with bacterial pneumonia, 9.4% were prescribed any antibiotic. A greater proportion of children covered by capitated payments (22.3%) were given treatment consistent with the guidelines compared with payment for event (1.3%). Conclusion. In this first study from Colombia, adherence to guidelines for outpatient treatment of children with bacterial pneumonia was low and was better for viral pneumonia. Further qualitative studies are needed to explore the reasons for this lack of adherence and why bacterial pneumonia was the most commonly reported etiology.

RESUMEN Objetivos. Determinar el nivel de adherencia a las directrices clínicas al momento de prescribir amoxicilina a menores de 5 años con neumonía en entornos de atención ambulatoria en Colombia entre el 2017 y el 2019, así como evaluar los factores asociados con la adherencia. Métodos. Este fue un estudio transversal de datos secundarios de la base de datos del Sistema Integral de Información de la Protección Social de Colombia. La adherencia se definió como la prescripción de amoxicilina por vía oral para las neumonías bacterianas y no especificadas, y la ausencia de prescripción para las neumonías virales. Las variables examinadas incluyeron: edad (< 1 año, 1 a 4 años); sexo; causa de la neumonía (bacteriana, viral, no especificada); región (andina, amazónica, Pacífico, Caribe, insular, Orinoco); y mecanismo de pago (sin autorización previa, capitación, pago directo, pago por caso, pago por evento). Resultados. De 215 925 casos de neumonía adquirida en la comunidad notificados durante el período 2017-2019, el 64,8% correspondieron a la región andina, el 73,9% a neumonía bacteriana y el 1,8% a neumonía viral. Se observó la adherencia a las directrices en el 5,8% de los casos: esta cifra fue más alta para la población infantil diagnosticada con neumonía viral (86,0%) que para la diagnosticada con neumonía bacteriana (2,0%). En el caso de la población infantil diagnosticada con neumonía bacteriana, al 9,4% se le recetó algún antibiótico. La proporción de población infantil cubierta por pagos capitados (22,3%) que recibió un tratamiento en consonancia con las directrices fue mayor que la de la población cubierta por pagos por evento (1,3%). Conclusión. En este primer estudio de Colombia, la adherencia a las directrices sobre el tratamiento ambulatorio de la población infantil con neumonía bacteriana fue bajo, en tanto que resultó superior en el caso de la neumonía viral. Se necesitan más estudios cualitativos para indagar sobre los motivos de esta falta de adherencia y las razones por las cuales la neumonía bacteriana fue la etiología notificada con mayor frecuencia.

RESUMO Objetivos. Determinar o nível de adesão às diretrizes clínicas para prescrição de amoxicilina em regime ambulatorial para crianças menores de 5 anos com pneumonia na Colômbia, de 2017 a 2019, e avaliar os fatores associados à adesão. Métodos. Estudo transversal de dados secundários do banco de dados do Sistema Integrado de Informação sobre Proteção Social da Colômbia. Definiu-se adesão como prescrição de amoxicilina oral para pneumonia bacteriana e não especificada, e não prescrição para pneumonia viral. As variáveis examinadas incluíram: idade da criança (< 1 ano, 1-4 anos), sexo, etiologia da pneumonia (bacteriana, viral, não especificada), região (Andina, Amazônica, Pacífica, Caribenha, Insular, Orinoco) e mecanismo de pagamento (sem autorização prévia, capitação, pagamento direto, pay-per-case, pay-for-event). Resultados. Dos 215.925 casos de pneumonia adquirida na comunidade notificados nos anos 2017-2019, 64,8% ocorreram na região Andina, 73,9% foram pneumonia bacteriana e 1,8% foram pneumonia viral. A adesão às diretrizes foi observada em 5,8% dos casos. Foi maior para crianças com diagnóstico de pneumonia viral (86,0%) em comparação com pneumonia bacteriana (2,0%). Para as crianças com diagnóstico de pneumonia bacteriana, 9,4% receberam algum antibiótico. Uma proporção maior de crianças cobertas por pagamentos capitados (22,3%) recebeu tratamento compatível com as diretrizes, contra apenas 1,3% no esquema de pay-for-event. Conclusão. Neste primeiro estudo da Colômbia, a adesão às diretrizes para tratamento ambulatorial de crianças com pneumonia bacteriana foi baixa, sendo melhor para pneumonia viral. Mais estudos qualitativos são necessários para explorar as razões dessa falta de adesão e por qual motivo a pneumonia bacteriana foi a etiologia mais comumente notificada.

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.

Food grade titanium dioxide accumulation leads to cellular alterations in colon cells after removal of a 24-hour exposure.

Titanium dioxide food grade (E171) is one of the most used food additives containing nanoparticles. Recently, the European Food Safety Authority indicated that E171 could no longer be considered safe as a food additive due to the possibility of it being genotoxic and there is evidence that E171 administration exacerbates colon tumor formation in murine models. However, less is known about the effects of E171 accumulation once the exposure stopped, then we hypothesized that toxic effects could be detected even after E171 removal. Therefore, we investigated the effects of E171 exposure after being removed from colon cell cultures. Human colon cancer cell line (HCT116) was exposed to 0, 1, 10 and 50 µg/cm2 of E171. Our results showed that in the absence of cytotoxicity, E171 was accumulated in the cells after 24 of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization. After the removal of E171, colon cells were cultured for 48 h more hours to analyze the ability to restore the previously detected alterations. As we hypothesized, the removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.

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

Latin-America (LATAM) is the second region in gastric cancer incidence; gastric adenocarcinoma (GA) represents 95% of all cases. We provide a mutational landscape of GA highlighting a) germline pathogenic variants associated with hereditary GA, b) germline risk variants associated with sporadic GA, and c) somatic variants present in sporadic GA in LATAM, and analyze how this landscape can be applied for precision medicine. We found that Brazil, Chile, Colombia, Mexico, Peru, and Venezuela are the countries with more published studies from LATAM explicitly related to GA. Our analysis displayed that different germline pathogenic variants for the CDH1 gene have been identified for hereditary GA in Brazilian, Chilean, Colombian, and Mexican populations. An increased risk of developing somatic GA is associated with the following germline risk variants: IL-4, IL-8, TNF-α, PTGS2, NFKB1, RAF1, KRAS and MAPK1 in Brazilian; IL-10 in Chilean; IL-10 in Colombian; EGFR and ERRB2 in Mexican, TCF7L2 and Chr8q24 in Venezuelan population. The path from mutational landscape to precision medicine requires four development levels: 1) Data compilation, 2) Data analysis and integration, 3) Development and approval of clinical approaches, and 4) Population benefits. Generating local genomic information is the initial padlock to overcome to generate and apply precision medicine.

Particulate matter (PM10) destabilizes mitotic spindle through downregulation of SETD2 in A549 lung cancer cells.

Air pollution represents an environmental problem, impacting negatively in human health. Particulate matter of 10 µm or less in diameter (PM10) is related to pulmonary diseases, including lung cancer. Mitotic spindle is made up by chromosome-microtubule (MT) interactions, where SETD2 plays an important role in MT stability. SETD2 binds and activates α-TUBULIN sub-unit and promotes MT polymerization. Alongside this mechanism, the spindle assembly checkpoint (SAC) senses the adequate mitotic progression through proteins such as BUBR1, AURORA B and SURVIVIN. Alterations in MT dynamics as well as in SAC cause aneuploidy and chromosomal instability, a common phenotype in cancer cells. In this study, we evaluated the effect of PM10 in the expression and protein levels of SETD2, as well as the effect in the expression and protein levels of SAC and mitotic components involved in chromosomal segregation/mitosis, using the A549 lung cancer cell line. A549 cell cultures were exposed to PM10 (10 µg/cm2) for 24 h to evaluate the expression and protein levels of SETD2 (SETD2), TUBA1A (α-TUBULIN), CCNB1 (CYCLIN B1), BUB1B (BUBR1), AURKB (AURORA B) and BIRC5 (SURVIVIN). We observed that PM10 decreases the expression and protein levels of SETD2, α-TUBULIN and BUBR1 and increases the levels of AURORA B and SURVIVIN in A549 cells, compared with non-treated cells. PM10 also caused a decrease in mitotic index and in the percentage of cells in G2/M when compared with control group. Co-localization of SETD2/α -TUB was lower in PM10-treated cells in comparison with non-treated cells. Finally, micronuclei (MN) frequency was higher in PM10-treated cells in contrast with non-treated cells, being whole chromosomes more common in PM10-treated MN than in non-treated MN. Our results suggest that PM10 causes missegregation and aneuploidy through downregulation of SETD2 and SAC components, inducing aneuploidy and predisposing to the generation of chromosomal instability in transformed cells.

Nucleotide Excision Repair Pathway Activity Is Inhibited by Airborne Particulate Matter (PM10) through XPA Deregulation in Lung Epithelial Cells.

Airborne particulate matter with a diameter size of ≤10 µm (PM10) is a carcinogen that contains polycyclic aromatic hydrocarbons (PAH), which form PAH-DNA adducts. However, the way in which these adducts are managed by DNA repair pathways in cells exposed to PM10 has been partially described. We evaluated the effect of PM10 on nucleotide excision repair (NER) activity and on the levels of different proteins of this pathway that eliminate bulky DNA adducts. Our results showed that human lung epithelial cells (A549) exposed to 10 µg/cm2 of PM10 exhibited PAH-DNA adducts as well as an increase in RAD23 and XPD protein levels (first responders in NER). In addition, PM10 increased the levels of H4K20me2, a recruitment signal for XPA. However, we observed a decrease in total and phosphorylated XPA (Ser196) and an increase in phosphatase WIP1, aside from the absence of XPA-RPA complex, which participates in DNA-damage removal. Additionally, an NER activity assay demonstrated inhibition of the NER functionality in cells exposed to PM10, indicating that XPA alterations led to deficiencies in DNA repair. These results demonstrate that PM10 exposure induces an accumulation of DNA damage that is associated with NER inhibition, highlighting the role of PM10 as an important contributor to lung cancer.

Particulate Matter (PM10) Promotes Cell Invasion through Epithelial-Mesenchymal Transition (EMT) by TGF-ß Activation in A549 Lung Cells.

Air pollution presents a major environmental problem, inducing harmful effects on human health. Particulate matter of 10 µm or less in diameter (PM10) is considered an important risk factor in lung carcinogenesis. Epithelial-mesenchymal transition (EMT) is a regulatory program capable of inducing invasion and metastasis in cancer. In this study, we demonstrated that PM10 treatment induced phosphorylation of SMAD2/3 and upregulation of SMAD4. We also reported that PM10 increased the expression and protein levels of TGFB1 (TGF-ß), as well as EMT markers SNAI1 (Snail), SNAI2 (Slug), ZEB1 (ZEB1), CDH2 (N-cadherin), ACTA2 (α-SMA), and VIM (vimentin) in the lung A549 cell line. Cell exposed to PM10 also showed a decrease in the expression of CDH1 (E-cadherin). We also demonstrated that expression levels of these EMT markers were reduced when cells are transfected with small interfering RNAs (siRNAs) against TGFB1. Interestingly, phosphorylation of SMAD2/3 and upregulation of SMAD induced by PM10 were not affected by transfection of TGFB1 siRNAs. Finally, cells treated with PM10 exhibited an increase in the capacity of invasiveness because of EMT induction. Our results provide new evidence regarding the effect of PM10 in EMT and the acquisition of an invasive phenotype, a hallmark necessary for lung cancer progression.

Differential response of immobile (pneumocytes) and mobile (monocytes) barriers against 2 types of metal oxide nanoparticles.

BACKGROUND: Inhaled nanoparticles (NPs) challenges mobile and immobile barriers in the respiratory tract, which can be represented by type II pneumocytes (immobile) and monocytes (mobile) but what is more important for biological effects, the cell linage, or the type of nanoparticle? Here, we addressed these questions and we demonstrated that the type of NPs exerts a higher influence on biological effects, but cell linages also respond differently against similar type of NPs. DESIGN: Type II pneumocytes and monocytes were exposed to tin dioxide (SnO2) NPs and titanium dioxide (TiO2) NPs (1, 10 and 50 µg/cm2) for 24 h and cell viability, ultrastructure, cell granularity, molecular spectra of lipids, proteins and nucleic acids and cytoskeleton architecture were evaluated. RESULTS: SnO2 NPs and TiO2 NPs are metal oxides with similar physicochemical properties. However, in the absence of cytotoxicity, SnO2 NPs uptake was low in monocytes and higher in type II pneumocytes, while TiO2 NPs were highly internalized by both types of cells. Monocytes exposed to both types of NPs displayed higher number of alterations in the molecular patterns of proteins and nuclei acids analyzed by Fourier-transform infrared spectroscopy (FTIR) than type II pneumocytes. In addition, cells exposed to TiO2 NPs showed more displacements in FTIR spectra of biomolecules than cells exposed to SnO2 NPs. Regarding cell architecture, microtubules were stable in type II pneumocytes exposed to both types of NPs but actin filaments displayed a higher number of alterations in type II pneumocytes and monocytes exposed to SnO2 NPs and TiO2 NPs. NPs exposure induced the formation of large vacuoles only in monocytes, which were not seen in type II pneumocytes. CONCLUSIONS: Most of the cellular effects are influenced by the NPs exposure rather than by the cell type. However, mobile, and immobile barriers in the respiratory tract displayed differential response against SnO2 NPs and TiO2 NPs in absence of cytotoxicity, in which monocytes were more susceptible than type II pneumocytes to NPs exposure.

Airborne particulate matter induces oxidative damage, DNA adduct formation and alterations in DNA repair pathways.

Air pollution, which includes particulate matter (PM), is classified in group 1 as a carcinogen to humans by the International Agency for Research in Cancer. Specifically, PM exposure has been associated with lung cancer in patients living in highly polluted cities. The precise mechanism by which PM is linked to cancer has not been completely described, and the genotoxicity induced by PM exposure plays a relevant role in cell damage. In this review, we aimed to analyze the types of DNA damage and alterations in DNA repair pathways induced by PM exposure, from both epidemiological and toxicological studies, to comprehend the contribution of PM exposure to carcinogenesis. Scientific evidence supports that PM exposure mainly causes oxidative stress by reactive oxygen species (ROS) and the formation of DNA adducts, specifically by polycyclic aromatic hydrocarbons (PAH). PM exposure also induces double-strand breaks (DSBs) and deregulates the expression of some proteins in DNA repair pathways, precisely, base and nucleotide excision repairs and homologous repair. Furthermore, specific polymorphisms of DNA repair genes could lead to an adverse response in subjects exposed to PM. Nevertheless, information about the effects of PM on DNA repair pathways is still limited, and it has not been possible to conclude which pathways are the most affected by exposure to PM or if DNA damage is repaired properly. Therefore, deepening the study of genotoxic damage and alterations of DNA repair pathways is needed for a more precise understanding of the carcinogenic mechanism of PM.

Long non-coding RNA NORAD upregulation induced by airborne particulate matter (PM10) exposure leads to aneuploidy in A549 lung cells.

Air pollution is a worldwide problem that affects human health predominantly in the largest cities. Particulate matter of 10 µm or less in diameter (PM10) is considered a risk factor for multiple diseases, including lung cancer. The long non-coding RNA NORAD and the components of the spindle assembly checkpoint (SAC) ensure proper chromosomal segregation. Alterations in the SAC cause aneuploidy, a feature associated with carcinogenesis. In this study, we demonstrated that PM10 treatment increased the expression levels of NORAD as well as those of SAC components mitotic arrest deficient 1 (MAD1L1), mitotic arrest deficient 2 (MAD2L1), BubR1 (BUB1B), aurora B (AURKB), and survivin (BIRC5) in the lung A549 cell line. We also demonstrated that MAD1L1, MAD2L1, and BUB1B expression levels were reduced when cells were transfected with small interfering RNAs (siRNAs) against NORAD. Interestingly, the expression levels of AURKB and BIRC5 (survivin) were not affected by transfection with NORAD siRNAs. Cells treated with PM10 exhibited a decrease in mitotic arrest and an increase in micronuclei frequency in synchronized A549 cells. PM10 exposure induced aneuploidy events as a result of SAC deregulation. We also observed a reduction in the protein levels of Pumilio 1 after PM10 treatment. Our results provide novel clues regarding the effect of PM10 in the generation of chromosomal instability, a phenotype observed in lung cancer cells.

Toxicity of engineered nanomaterials with different physicochemical properties and the role of protein corona on cellular uptake and intrinsic ROS production.

The Organisation for Economic Co-operation and Development has listed thirteen engineered nanomaterials (ENM) in order to investigate their toxicity on human health. Silicon dioxide (SiO2) and titanium dioxide (TiO2) are included on that list and we added indium tin oxide (ITO) nanoparticles (NPs) to our study, which is not listed on OECD suggested ENM to be investigated, however ITO NPs has a high potential of industrial production. We evaluate the physicochemical properties of SiO2 NPs (10-20 nm), TiO2 nanofibers (NFs; 3 µm length) and ITO NPs (<50 nm) and the impact of protein-corona formation on cell internalization. Then, we evaluated the toxicity of uncoated ENM on human lung epithelial cells exposed to 10 and 50 µg/cm2 for 24 h. TiO2 NFs showed the highest capability to adsorb proteins onto the particle surface followed by SiO2 NPs and ITO NPs after acellular incubation with fetal bovine serum. The protein adsorption had no impact on Alizarin Red S conjugation, intrinsic properties for reactive oxygen (ROS) formation or cell uptake for all types of ENM. Moreover, TiO2 NFs induced highest cell alterations in human lung epithelial cells exposed to 10 and 50 µg/cm2 while ITO NPs induced moderated cytotoxicity and SiO2 NPs caused even lower cytotoxicity under the same conditions. DNA, proteins and lipids were mainly affected by TiO2 NFs followed by SiO2 NPs with toxic effects in protein and lipids while limited variations were detected after exposure to ITO NPs on spectra analyzed by Fourier Transform Infrared Spectroscopy.