Identification of ABCC3 and its isoforms as potential biomarker in hepatocellular carcinoma.

Liver diseases preceding the occurrence of hepatocellular carcinoma (HCC) play a crucial role in the progression and establishment of HCC, a malignancy ranked as the third deadliest cancer worldwide. Late diagnosis, alongside ineffective treatment, leads patients to a poor survival rate. This scenario argues for seeking novel alternatives for detecting liver alterations preceding the early occurrence of HCC. Experimental studies have reported that ABCC3 protein increases within HCC tumors but not in adjacent tissue. Therefore, we analyzed ABCC3 expression in public databases and investigated the presence of ABCC3 and its isoforms in plasma, urine and its release in extracellular vesicles (EVs) cargo from patients bearing cirrhosis and HCC. The UALCAN and GEPIA databases were used to analyze the expression of ABCC3 in HCC. The results were validated in a case-control study including 41 individuals bearing cirrhosis and HCC, and the levels of ABCC3 in plasma and urine samples, as well as EVs, were analyzed by ELISA and western blot. Our data showed that ABCC3 expression was higher in HCC tissues than in normal tissues and correlated with HCC grade and stage. ABCC3 protein levels were highly increased in both plasma and urine and correlated with liver disease progression and severity. The isoforms MRP3A and MRP3B of ABCC3 were significantly increased in both EVs and plasma/urine of patients bearing HCC. ABCC3 expression gradually increases in HCC tissues, and its protein levels are increased in both plasma and urine of patients with cirrhosis and HCC. MRP3A and MRP3B isoforms have the potential to be prognostic biomarkers of HCC.

Gßγ mediates activation of Rho guanine nucleotide exchange factor ARHGEF17 that promotes metastatic lung cancer progression.

Metastatic lung cancer is a major cause of death worldwide. Dissemination of cancer cells can be facilitated by various agonists within the tumor microenvironment, including by lysophosphatidic acid (LPA). We postulate that Rho guanine nucleotide exchange factors (RhoGEFs), which integrate signaling cues driving cell migration, are critical effectors in metastatic cancer. Specifically, we addressed the hypothetical role of ARHGEF17, a RhoGEF, as a potential effector of Gßγ in metastatic lung cancer cells responding to LPA. Here, we show that ARHGEF17, originally identified as a tumor endothelial marker, is involved in tumor growth and metastatic dissemination of lung cancer cells in an immunocompetent murine model. Gene expression-based analysis of lung cancer datasets showed that increased levels of ARHGEF17 correlated with reduced survival of patients with advanced-stage tumors. Cellular assays also revealed that this RhoGEF participates in the invasive and migratory responses elicited by Gi protein-coupled LPA receptors via the Gßγ subunit complex. We demonstrate that this signaling heterodimer promoted ARHGEF17 recruitment to the cell periphery and actin fibers. Moreover, Gßγ allosterically activates ARHGEF17 by the removal of inhibitory intramolecular restrictions. Taken together, our results indicate that ARHGEF17 may be a valid potential target in the treatment of metastatic lung cancer.

Spent coffee grounds as feedstock for the production of biosurfactants and the improved recovery of melanoidins.

Spent coffee grounds (SCG) are wastes generated in high amounts worldwide. Their composition makes them a promising feedstock for biotechnological processes. Here we show that the production of the biosurfactant surfactin by submerged culture of a Bacillus subtilis strain growing on SCG is possible, reaching concentrations up to 8.8 mg/L when using SCG at 8.3 g/L in the medium. In addition, we report a synergy between the production of surfactin and the recovery of melanoidins, an added-value compound already present in SCG. More specifically, the concentration of melanoidins in the culture medium increased between 2.1 and 2.5 times thanks to the presence of the B. subtilis in the culture. Furthermore, we have observed a strong interaction between surfactin and melanoidin aggregates through dynamic light scattering measurements, and that both of them can be co-purified with an acid precipitation. We have also characterized the interfacial and antioxidant properties of the cell-free supernatant and surfactin extract, as well as the distribution of the congeners of the biosurfactant. Altogether, this work describes a promising approach to obtain biosurfactants and antioxidant molecules in a single operation, which can be used to design several new formulations of interest for bioremediation, amendment of soils, food and cosmetics.

An Assessment of Old and New Characters Using Traditional and Geometric Morphometrics for the Identification of Dendroctonus approximatus and Dendroctonus parallelocollis (Curculionidae: Scolytinae).

There have been numerous changes in the nomenclature of species of Dendroctonus. The case of Dendroctonus parallelocollis Chapuis and Dendroctonus approximatus Dietz has been particularly noteworthy. These bark beetles colonize pine trees but are not aggressive species. The high morphological similarity, their overlapping geographical distribution, and the limited knowledge of these species have resulted in taxonomic confusion. The aim of the present study was to assess morphological characters reported in the literature and to scrutinize new characters that might be useful for the separation of these species. We evaluated 26 morphological attributes and performed geometric morphometrics analysis of the antenna, pronotum, spermatheca, and seminal rod to test if the variations in the shape of these structures allow the recognition of additional discrete characters to differentiate them. Our results show that five double-state characters of external morphology are useful to identify these species, and the shape of antenna, spermatheca, and seminal rod.

Aquatic toxicity and biodegradability of a surfactant produced by Bacillus subtilis ICA56.

In this work, the environmental compatibility of a biosurfactant produced by a Bacillus subtilis strain isolated from the soil of a Brazilian mangrove was investigated. The biosurfactant, identified as surfactin, is able to reduce surface tension (ST) to 31.5 ± 0.1 mN m-1 and exhibits a lowcritical micelle concentration (CMC) value (0.015 ± 0.003 g L-1). The highest crude biosurfactant concentration (224.3 ± 1.9 mg L-1) was reached at 72 h of fermentation. Acute toxicity tests, carried out with Daphnia magna, Vibrio fischeri and Selenastrum capricornutum indicated that the toxicity of the biosurfactant is lower than that of its chemically derived counterparts. The results of the biodegradability tests demonstrated that the crude surfactin extract was degraded by both Pseudomonas putida and a mixed population from a sewage-treatment plant, in both cases the biodegradation efficiency being dependent on the initial concentration of the biosurfactant. Finally, as the biodegradation percentages obtained fall within the acceptance limits established by the Organization for Economic Co-operation and Development (Guidelines for Testing of Chemicals, OECD 301E), crude surfactin can be classified as a "readily" biodegradable compound.

The transmembrane transporter ABCC3 participates in liver cancer progression and is a potential biomarker.

The poor prognosis, few available treatment options, and multidrug resistance present in hepatocellular carcinoma are major problems, and new early biomarkers are needed to reduce the liver cancer death rate. ATP-binding cassette sub-family C member 3 (Abcc3) is overexpressed in different cancers and is associated with multidrug resistance and a carcinogenic stem cell phenotype. We present evidence for the first time that ABCC3 is a potential sanguine biomarker and anticancer target in hepatocellular carcinoma. Abcc3 mRNA expression was elevated in liver nodules and tumors in rat hepatocarcinogenesis model. Accordingly, the ABCC3 protein was preferentially overexpressed within the nodules and tumors during hepatocellular carcinoma progression and was secreted into the bloodstream of rat hepatocarcinogenesis model. The ABCC3 protein was expressed in human hepatoma cells and, importantly, was also present in HepG2- and Huh7-conditioned media. Furthermore, ABCC3 was overexpressed in human hepatocellular carcinoma. This report is the first to describe liver overexpression of Abcc3 during the cancer initiation, promotion, and progression periods in rat hepatocarcinogenesis model and in human hepatocellular carcinoma.

Crystal structure of Bacillus subtilis GabR, an autorepressor and transcriptional activator of gabT.

Bacillus subtilis GabR is a transcription factor that regulates gamma-aminobutyric acid (GABA) metabolism. GabR is a member of the understudied MocR/GabR subfamily of the GntR family of transcription regulators. A typical MocR/GabR-type regulator is a chimeric protein containing a short N-terminal helix-turn-helix DNA-binding domain and a long C-terminal pyridoxal 5'-phosphate (PLP)-binding putative aminotransferase domain. In the presence of PLP and GABA, GabR activates the gabTD operon, which allows the bacterium to use GABA as nitrogen and carbon sources. GabR binds to its own promoter and represses gabR transcription in the absence of GABA. Here, we report two crystal structures of full-length GabR from B. subtilis: a 2.7-Å structure of GabR with PLP bound and the 2.55-Å apo structure of GabR without PLP. The quaternary structure of GabR is a head-to-tail domain-swap homodimer. Each monomer comprises two domains: an N-terminal winged-helix DNA-binding domain and a C-terminal PLP-binding type I aminotransferase-like domain. The winged-helix domain contains putative DNA-binding residues conserved in other GntR-type regulators. Together with sedimentation velocity and fluorescence polarization assays, the crystal structure of GabR provides insights into DNA binding by GabR at the gabR and gabT promoters. The absence of GabR-mediated aminotransferase activity in the presence of GABA and PLP, and the presence of an active site configuration that is incompatible with stabilization of the GABA external aldimine suggest that a GabR aminotransferase-like activity involving GABA and PLP is not essential to its primary function as a transcription regulator.

4EBP1 Is Dephosphorylated by Respiratory Syncytial Virus Infection.

Respiratory syncytial virus (RSV) requires protein biosynthesis machinery to generate progeny. There is evidence that RSV might alter some translation components since stress granules are formed in their host cells. Consistent with these observations, we found that RSV induces dephosphorylation of 4EBP1 (eIF4E-binding protein), an important cellular translation factor. Our results show no correlation between the 4EBP1 dephosphorylation time and the decrease in the global rate of protein synthesis. Interestingly, treatment with rapamycin stimulates virus generation. The results suggest that RSV is a virus that still contains unknown mechanisms involved in the translation of their mRNAs through the alteration or modification of some translation factors, such as 4EBP1, possibly to favor its replicative cycle.

CORESIDENCE: National and subnational data on household size and composition around the world, 1964-2021.

The CORESIDENCE Database (CoDB) represents a significant advancement in the field of family studies, addressing existing data gaps and facilitating comprehensive analysis of households' composition and living arrangements at the national and subnational levels. This article introduces the CoDB, developed for the ERC project Intergenerational Coresidence in Global Perspective: Dimensions of Change. The database draws on global-scale individual microdata from four main repositories and national household surveys, encompassing over 150 million individual records representing more than 98% of the world's population. The CoDB provides datasets at the national, subnational, and subnational-harmonized levels, covering 156 countries, 3950 regions, and 1511 harmonized regions for the period 1964-2021. It includes 146 indicators on household composition and family arrangements, allowing researchers to explore intergenerational co-residence patterns, gender dynamics within households, and longitudinal trends in living arrangements. The CoDB fills an important gap in comparative household studies, enabling researchers to undertake ground breaking research at both macro and micro levels, ultimately fostering a deeper understanding of the complex dynamics of family structures and living arrangements.

Breaking paradigms: Long non-coding RNAs forming gene fusions with potential implications in cancer.

Long non-coding RNAs (lncRNAs) are non-coding RNAs longer than 200 nucleotides with dynamic regulatory functions. They interact with a wide range of molecules such as DNA, RNA, and proteins to modulate diverse cellular functions through several mechanisms and, if deregulated, they can lead to cancer development and progression. Recently, it has been described that lncRNAs are susceptible to form gene fusions with mRNAs or other lncRNAs, breaking the paradigm of gene fusions consisting mainly of protein-coding genes. However, their biological significance in the tumor phenotype is still uncertain. Therefore, their recent identification opens a new line of research to study their biological role in tumorigenesis, and their potential as biomarkers with clinical relevance or as therapeutic targets. The present study aimed to review the lncRNA fusions identified so far and to know which of them have been associated with a potential function. We address the current challenges to deepen their study as well as the reasons why they represent a future therapeutic window in cancer.

Vaccine antibodies against a synthetic epidermal growth factor variant enhance the antitumor effects of inhibitors targeting the MAPK/ERK and PI3K/Akt pathways.

BACKGROUND: The EGFR pathway is involved in intrinsic and acquired resistance to a wide variety of targeted therapies in cancer. Vaccination represents an alternative to the administration of anti-EGFR monoclonal antibodies, such as cetuximab or panitumumab. Here, we tested if anti-EGF antibodies generated by vaccination (anti-EGF VacAbs) could potentiate the activity of drugs targeting the ERK/MAPK and PI3K/Akt pathways. METHODS: Non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and melanoma cell lines harboring KRAS, NRAS, BRAF and PIK3CA mutations were used. Anti-EGF VacAbs were obtained by immunizing rabbits with a fusion protein containing a synthetic, highly mutated variant of human EGF. Cell viability was determined by MTT, total and phosphorylated proteins by Western blotting, cell cycle distribution and cell death by flow cytometry and emergence of resistance by microscopic examination in low density cultures. RESULTS: Anti-EGF VacAbs potentiated the antiproliferative effects of MEK, KRAS G12C, BRAF, PI3K and Akt inhibitors in KRAS, NRAS, BRAF and PIK3CA mutant cells and delayed the appearance of resistant clones in vitro. The effects of anti-EGF VacAbs were comparable or superior to those of panitumumab and cetuximab. The combination of anti-EGF VacAbs with the targeted inhibitors effectively suppressed EGFR downstream pathways and sera from patients immunized with an anti-EGF vaccine also blocked activation of EGFR effectors. CONCLUSIONS: Anti-EGF VacAbs enhance the antiproliferative effects of drugs targeting the ERK/MAPK and PIK3CA/Akt pathways. Our data provide a rationale for clinical trials testing anti-EGF vaccination combined with inhibitors selected according to the patient's genetic profile.

[Risk factors for metabolic dysfunction-associated fatty liver disease in the Hispanic-Mexican population.] / Factores de riesgo de la enfermedad hepática grasa asociada a disfunción metabólica en población hispano-mexicana.

OBJECTIVE: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a poor attended disease, which has gained attention due the elevated number of cases in countries as Mexico, where the incidence is the number 4th globally. MAFLD develops in obese or overweighted individuals and is characterized by triglycerides accumulation in the liver, this condition can develop to hepatocellular carcinoma. It has been observed that MAFLD depends on the genetics and lifestyle. Due to the high prevalence of this disease among Hispanic population, we focused on this study in the characteristics and prevalence of MAFLD in Mexican patients. METHODS: In this study were included 572 overweighted and obese patients, who underwent a screening analysis using the fatty liver index (IHG), clinical parameters were analysed, demographic and comorbidities. Frequency of variables were obtained, and the data were analysed by Chi-square test or Fisher test, odd ratio (OR) and binary logistic regression. RESULTS: A MALFD prevalence of 37% were obtained, where the history of familiar obesity, paracetamol usage, carbohydrate and fat intake are shown to be risk factors. It was found that high blood pressure, central obesity and hypertriglyceridemia were also associated to the MAFLD development. On the other hand, physical exercise was a protector factor. CONCLUSIONS: Our results show the necessity to study the MAFLD causalities in Mexican patients, focused on the paracetamol intake.

OBJETIVO: La enfermedad hepática grasa asociada a disfunción metabólica (MAFLD) es una enfermedad poco considerada, que ha recibido atención debido al número de casos en países como México, donde ocupa el 4º lugar mundial de incidencia. La MAFLD se desarrolla en personas con sobrepeso u obesidad y se caracteriza por la acumulación de triglicéridos en el hígado, donde puede evolucionar hacia carcinoma hepatocelular. Se ha observado que la MAFLD depende de la genética y del estilo de vida. Tomando en cuenta la alta prevalencia de MAFLD en la población hispana, nos enfocamos en este trabajo en estudiar la prevalencia y características relacionadas con esta enfermedad en pacientes mexicanos. METODOS: En este estudio se incluyeron 572 pacientes con sobrepeso u obesidad, a los cuales se les realizó un análisis de cribado mediante el índice de hígado graso (IHG), se analizaron parámetros clínicos, demográficos y comorbilidades. Se obtuvieron frecuencias de las variables y se analizaron los datos mediante chi cuadrado o exacta de Fisher, razón de momios (OR) y regresión logística binaria. RESULTADOS: Se obtuvo una prevalencia del 37% de MAFLD, donde la historia familiar de obesidad, el uso de paracetamol, así como el consumo de carbohidratos y grasas fueron factores de riesgo para su desarrollo. Se encontró que la hipertensión arterial, la obesidad visceral y la hipertrigliceridemia también estaban asociados al desarrollo de la MAFLD. Por otro lado, el ejercicio fue un factor protector. CONCLUSIONES: Nuestros resultados ponen de manifiesto la necesidad de realizar estudios relacionados con las causalidades de la MAFLD en los pacientes mexicanos, principalmente en el uso del paracetamol.

Overcoming MET-mediated resistance in oncogene-driven NSCLC.

This study evaluates the efficacy of combining targeted therapies with MET or SHP2 inhibitors to overcome MET-mediated resistance in different NSCLC subtypes. A prevalence study was conducted for MET amplification and overexpression in samples from patients with NSCLC who relapsed on ALK, ROS1, or RET tyrosine kinase inhibitors. MET-mediated resistance was detected in 37.5% of tissue biopsies, which allow the detection of MET overexpression, compared to 7.4% of liquid biopsies. The development of drug resistance by MET overexpression was confirmed in EGFRex19del-, KRASG12C-, HER2ex20ins-, and TPM3-NTRK1-mutant cell lines. The combination of targeted therapy with MET or SHP2 inhibitors was found to overcome MET-mediated resistance in both in vitro and in vivo assays. This study highlights the importance of considering MET overexpression as a resistance driver to NSCLC targeted therapies to better identify patients who could potentially benefit from combination approaches with MET or SHP2 inhibitors.

Gender differences in time use across age groups: A study of ten industrialized countries, 2005-2015.

This study uses largescale cross-national time-diary data from the Multinational Time Use Study (MTUS) (N = 201,972) covering the period from 2005 to 2015 to examine gender differences in time use by age groups. The study compares ten industrialized countries across Asia, Europe, and North America. In all ten countries, gender differences in time use are smaller in personal care, sleeping and meals, followed by leisure time (including screen-based leisure and active leisure), and largest in housework, care work and paid work activities. Gender disparities in time use are higher in South Korea, Hungary, and Italy, followed closely by Spain, with moderate gender gaps in Western European countries like France and Netherlands, and lowest differences in Finland and Anglo-Saxon countries, including Canada, US, and the UK. Gender differences in housework and caring time increase from adolescence (10-17 years) to early adulthood (18-29 years), showing strong gender gaps in early/middle adulthood (30-44 years), but narrow again during late adulthood (65 years or older). However, the age gradient in care work and housework is most pronounced in Italy and South Korea, being less prominent in Canada and Finland. Gender gaps in paid work are larger in early/middle adulthood (30-44) and middle/late adulthood (45-64), with strongest age gradients observed in the Netherlands and weaker gradients for the US. Gender differences in active leisure increase by age, especially in Southern European countries, while screen-based leisure shows more stable gender gaps by age groups across different countries. Overall, this study shows that age and gender intersect strongly in affecting time-use patterns, but also that the national context plays an important role in shaping gender-age interactions in time use allocation.

The EPICAL trial, a phase Ib study combining first line afatinib with anti-EGF vaccination in EGFR-mutant metastatic NSCLC.

INTRODUCTION: Combination of anti-EGFR monoclonal antibodies or immune checkpoint inhibitors with TKIs has shown minimal benefit in EGFR mutant (EGFR-mut) NSCLC patients. Consequently, new combination approaches are needed. PATIENTS AND METHODS: The EPICAL was a single arm, phase 1b study to evaluate safety, tolerability and anti-tumor activity of first line afatinib combined with anti-EGF vaccination in advanced EGFR-mut patients. EGFR status and mutations in liquid biopsies were determined by reverse transcriptase-polymerase chain reaction; serum biomarkers by ELISA and Western blotting analysis. RESULTS: The assay enrolled 23 patients, 21 completed the anti-EGF immunization phase. Treatment was well tolerated and no serious adverse events (SAEs) related to the anti-EGF vaccine were reported. Objective response and disease control rates were 78.3% (95%CI = 53.6-92.5) and 95.7% (95%CI = 78.1-99.9), respectively. After a median follow-up of 24.2 months, median progression-free survival (PFS) was 14.8 months (95% CI = 9.5-20.1) and median overall survival (OS) 26.9 months (95% CI = 23.0-30.8). Among the 21 patients completing the immunization phase, PFS was 17.5 months (95% CI = 12.0-23.0) and OS 26.9 months (95% CI = 24.6-NR). At the end of the immunization phase, all 21 patients showed high serum titers of anti-EGF antibodies, while EGF levels had decreased significantly. Finally, treatment with fully immunized patient's sera inhibited the EGFR pathway in tumor cells growing in vitro. CONCLUSIONS: Combination treatment with an anti-EGF vaccine is well tolerated; induces a sustained immunogenic effect and might enhance the clinical efficacy of EGFR TKIs.

Prevalence of SARS-CoV-2 Infection in a Sample of Health Workers in Two Health Departments of the Valencian Community in Spain.

Health care personnel constitutes the most vulnerable group of professionals, as they are employed in a work context with higher exposure to SARS-CoV-2 infection. This study aims to estimate the prevalence of SARS-CoV-2 infection in health personnel (n = 2858) of two health departments in the Valencian community between March 2020 and April 2021, as well as the sociodemographic and work variables predicting higher infection prevalence in this group. A cross-sectional descriptive study was performed on health workers from the health departments of Torrevieja and Elche-Crevillente of the Valencian Community (Spain). After obtaining the samples, the cases were identified through an active infection diagnostic test (AIDT). The analyzed variables were: sex, age (18-34/35-49/>50 years), professional category, health care, risk service, and AIDT. A total of 2858 staff members were studied. Of them, 55.4% (1582) underwent an AIDT, with 9.7% (277) of positive cases. Infection predominated in the age group of 18 to 34 years, 12.6% (OR = 1.98, 95% CI [1.26, 3.11]); nurses, 12.1% (OR = 1.5, 95% CI [1.00, 2.23]); and at-risk services, 11.4% (OR = 1.3, 95% CI [1.06, 1.81]). A very low positivity rate was identified in the health personnel linked to the health departments analyzed during the 14 months of the study period. Based on our results, prevention strategies could focus more intensively on the most at-risk groups, specifically young nurses who work in at-risk services, mainly in emergency and internal medicine.

Anti-epidermal growth factor vaccine antibodies increase the antitumor activity of kinase inhibitors in ALK and RET rearranged lung cancer cells.

Advanced NSCLC patients harboring EML4-ALK and CCDC6-RET rearrangements derive benefit from treatment with ALK and RET TKIs but not immune checkpoint inhibitors. New immunotherapeutic approaches, such as immunization against growth factors, can be of particular interest for combination treatment in these patients. Here, we investigated the effects of anti-EGF antibodies generated by vaccination (anti-EGF VacAbs), TKIs and combinations in EML4-ALK and CCDC6-RET NSCLC cell lines. We found that EGF and tumor growth factor alpha (TGFα) significantly decreased the antiproliferative activity of the RET inhibitor BLU-667 in CCDC6-RET cells and brigatinib, alectinib and crizotinib in EML4-ALK translocated cells. The addition of anti-EGF VacAbs reversed the effects of EGF and TGFα, potentiated the antitumor effects of the kinase inhibitors and delayed the appearance in vitro of resistant clones. Western blotting demonstrated that the combination of anti-EGF VacAbs with ALK or RET TKIs effectively suppressed EGFR downstream pathways in EML4-ALK translocated and CCDC6-RET cells, respectively. In conclusion, anti-EGF VacAbs significantly increased the antitumor activity of TKIs in ALK and RET-positive cell lines. Clinical trials of an EGF vaccine in combination with ALK and RET TKIs are warranted.

The implications of ABCC3 in cancer drug resistance: can we use it as a therapeutic target?

Drug resistance is one of the main causes of chemotherapy failure. Although several factors are involved in cancer drug resistant, the exporter pumps overexpression that mediates the drugs flow to outside the cells and reduces both the drugs intracellular concentration and effectiveness, has been one of the most important challenges. Overexpression of ABCC3, a member of the ABCC subfamily, has been strongly associated to the resistance to multiple drugs. ABCC3 has been found highly expressed in different types of cancers and is associated with poor prognosis and resistance to treatments. In this review, we summarize the molecular mechanisms involved in cancer drug resistance and discuss the current knowledge about the structure, function and role of ABCC3 in drug resistance, as well as, the expression status of ABCC3 in different types of cancer. We also provide evidences that place ABCC3 as a potential therapeutic target for improving the cancer treatment by focusing on the need of developing more effective cancer therapies to target ABCC3 in translational researches.

VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells.

Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl2) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl2 promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl2-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl2-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl2 in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent Fyn kinase activation.

Celecoxib activates Stat5 and restores or increases the expression of growth hormone-regulated genes in hepatocarcinogenesis.

We have previously evaluated the chemopreventive effect of celecoxib on preneoplastic lesions in rat liver. However, though the effects of celecoxib have been tested in a variety of carcinomas, there has not been a study on the modulation of gene expression in response to this drug. Here, we evaluated the effect of celecoxib on the gene expression profile associated with hepatocarcinogenesis. Male Sprague-Dawley rats underwent the modified resistant hepatocyte model and were fed a diet containing 1500 ppm of celecoxib. Gene expression profiles were evaluated using DNA microarrays and further validations were performed using quantitative PCR, western blotting and immunohistochemical staining. Celecoxib modulated the expression of 46 genes, and those regulated by growth hormone were selected for further analysis. Celecoxib significantly upregulated the expression of the Cyp2b1/2, Cyp3a1, and alpha2-urinary globulin (alpha2uG) genes and restored the expression of Cyp2b3 to normal. The protein expression of Cyp2b1/2 was increased, but the expressions of Cyp3a1 and alpha2uG were only restored to normal levels. The increased Cyp2b1/2 expression in response to celecoxib was mainly confined to preneoplastic lesions. A search for the upstream mediator of these genetic alterations found that carcinogenesis inactivated by 87% the signal transducer and activator of transcription 5 (Stat5), a transcription factor that is activated by growth hormone signaling, but celecoxib treatment restored its activation. In conclusion, these results suggest that celecoxib exerts anticancer effects on altered hepatic cells by restoring mRNA and the protein expression levels of specific genes, in part through the reactivation of Stat5.