Physico-chemical characterization of the tumour microenvironment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy that accounts for more than 90% of pancreatic cancer diagnoses. Our research is focused on the physico-chemical properties of the tumour microenvironment (TME), including its tumoural extracellular matrix (tECM), as they may have an important impact on the success of cancer therapies. PDAC xenografts and their decellularized tECM offer a great material source for research in terms of biomimicry with the original human tumour. Our aim was to evaluate and quantify the physico-chemical properties of the PDAC TME. Both cellularized (native TME) and decellularized (tECM) patient-derived PDAC xenografts were analyzed. A factorial design of experiments identified an optimal combination of factors for effective xenograft decellularization. Our results provide a complete advance in our understanding of the PDAC TME and its corresponding stroma, showing that it presents an interconnected porous architecture with very low permeability and small pores due to the contractility of the cellular components. This fact provides a potential therapeutic strategy based on the therapeutic agent size.

Structural Validity and Internal Consistency of the Adolescents and Children Risk of Abuse and Maltreatment Parental Scale (ACRAM-PS)

There is a clear need for developing a comprehensive, unbiased, and psychometrically sound tool to assess child maltreatment. The aim of this study is to examine the structural validity, internal consistency, and convergent validity of a newly developed child maltreatment assessment instrument. A total of 286 professionals of the child protection system participated in the study, completing a total of 645 cases of children and adolescents. The Adolescents and Children Risk of Abuse and Maltreatment Parental Scale (ACRAM-PS), the Childhood Trauma Questionnaire Short Form (CTQ-SF) and other demographic variables were measured. Structural validity, internal consistency, and convergent validity of the ACRAM-PS were tested. This scale obtained good structural validity, internal consistency, and convergent validity as hypothesized patterns of correlations occurred as expected. This instrument implies a considerable improvement as it is comprehensive, psychometrically sound and, it has been articulated by its own users. It can significantly contribute to establish a common language among professionals, improve multidisciplinary communication, and optimize prevention, detection, and early intervention in child maltreatment.

Inhibiting NR5A2 targets stemness in pancreatic cancer by disrupting SOX2/MYC signaling and restoring chemosensitivity

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a profoundly aggressive and fatal cancer. One of the key factors defining its aggressiveness and resilience against chemotherapy is the existence of cancer stem cells (CSCs). The important task of discovering upstream regulators of stemness that are amenable for targeting in PDAC is essential for the advancement of more potent therapeutic approaches. In this study, we sought to elucidate the function of the nuclear receptor subfamily 5, group A, member 2 (NR5A2) in the context of pancreatic CSCs.

METHODS

We modeled human PDAC using primary PDAC cells and CSC-enriched sphere cultures. NR5A2 was genetically silenced or inhibited with Cpd3. Assays included RNA-seq, sphere/colony formation, cell viability/toxicity, real-time PCR, western blot, immunofluorescence, ChIP, CUT&Tag, XF Analysis, lactate production, and in vivo tumorigenicity assays. PDAC models from 18 patients were treated with Cpd3-loaded nanocarriers.

RESULTS

Our findings demonstrate that NR5A2 plays a dual role in PDAC. In differentiated cancer cells, NR5A2 promotes cell proliferation by inhibiting CDKN1A. On the other hand, in the CSC population, NR5A2 enhances stemness by upregulating SOX2 through direct binding to its promotor/enhancer region. Additionally, NR5A2 suppresses MYC, leading to the activation of the mitochondrial biogenesis factor PPARGC1A and a shift in metabolism towards oxidative phosphorylation, which is a crucial feature of stemness in PDAC. Importantly, our study shows that the specific NR5A2 inhibitor, Cpd3, sensitizes a significant fraction of PDAC models derived from 18 patients to standard chemotherapy. This treatment approach results in durable remissions and long-term survival. Furthermore, we demonstrate that the expression levels of NR5A2/SOX2 can predict the response to treatment.

CONCLUSIONS

The findings of our study highlight the cell context-dependent effects of NR5A2 in PDAC. We have identified a novel pharmacological strategy to modulate SOX2 and MYC levels, which disrupts stemness and prevents relapse in this deadly disease. These insights provide valuable information for the development of targeted therapies for PDAC, offering new hope for improved patient outcomes. A Schematic illustration of the role of NR5A2 in cancer stem cells versus differentiated cancer cells, along with the action of the NR5A2 inhibitor Cpd3. B Overall survival of tumor-bearing mice following allocated treatment. A total of 18 PDX models were treated using a 2 x 1 x 1 approach (two animals per model per treatment); n=36 per group (illustration created with biorender.com ).

Macrophages direct cancer cells through a LOXL2-mediated metastatic cascade in pancreatic ductal adenocarcinoma

OBJECTIVE

The lysyl oxidase-like protein 2 (LOXL2) contributes to tumour progression and metastasis in different tumour entities, but its role in pancreatic ductal adenocarcinoma (PDAC) has not been evaluated in immunocompetent in vivo PDAC models.

DESIGN

Towards this end, we used PDAC patient data sets, patient-derived xenograft in vivo and in vitro models, and four conditional genetically-engineered mouse models (GEMMS) to dissect the role of LOXL2 in PDAC. For GEMM-based studies, K-Ras +/LSL-G12D;Trp53 LSL-R172H;Pdx1-Cre mice (KPC) and the K-Ras +/LSL-G12D;Pdx1-Cre mice (KC) were crossed with Loxl2 allele floxed mice (Loxl2Exon2 fl/fl) or conditional Loxl2 overexpressing mice (R26Loxl2 KI/KI) to generate KPCL2KO or KCL2KO and KPCL2KI or KCL2KI mice, which were used to study overall survival; tumour incidence, burden and differentiation; metastases; epithelial to mesenchymal transition (EMT); stemness and extracellular collagen matrix (ECM) organisation.

RESULTS

Using these PDAC mouse models, we show that while Loxl2 ablation had little effect on primary tumour development and growth, its loss significantly decreased metastasis and increased overall survival. We attribute this effect to non-cell autonomous factors, primarily ECM remodelling. Loxl2 overexpression, on the other hand, promoted primary and metastatic tumour growth and decreased overall survival, which could be linked to increased EMT and stemness. We also identified tumour-associated macrophage-secreted oncostatin M (OSM) as an inducer of LOXL2 expression, and show that targeting macrophages in vivo affects Osm and Loxl2 expression and collagen fibre alignment.

CONCLUSION

Taken together, our findings establish novel pathophysiological roles and functions for LOXL2 in PDAC, which could be potentially exploited to treat metastatic disease.

Pharmacological targeting of the receptor ALK inhibits tumorigenicity and overcomes chemoresistance in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive disease characterized by its metastatic potential and chemoresistance. These traits are partially attributable to the highly tumorigenic pancreatic cancer stem cells (PaCSCs). Interestingly, these cells show unique features in order to sustain their identity and functionality, some of them amenable for therapeutic intervention. Screening of phospho-receptor tyrosine kinases revealed that PaCSCs harbored increased activation of anaplastic lymphoma kinase (ALK). We subsequently demonstrated that oncogenic ALK signaling contributes to tumorigenicity in PDAC patient-derived xenografts (PDXs) by promoting stemness through ligand-dependent activation. Indeed, the ALK ligands midkine (MDK) or pleiotrophin (PTN) increased self-renewal, clonogenicity and CSC frequency in several in vitro local and metastatic PDX models. Conversely, treatment with the clinically-approved ALK inhibitors Crizotinib and Ensartinib decreased PaCSC content and functionality in vitro and in vivo, by inducing cell death. Strikingly, ALK inhibitors sensitized chemoresistant PaCSCs to Gemcitabine, as the most used chemotherapeutic agent for PDAC treatment. Consequently, ALK inhibition delayed tumor relapse after chemotherapy in vivo by effectively decreasing the content of PaCSCs. In summary, our results demonstrate that targeting the MDK/PTN-ALK axis with clinically-approved inhibitors impairs in vivo tumorigenicity and chemoresistance in PDAC suggesting a new treatment approach to improve the long-term survival of PDAC patients.

Effects of self-regulated learning and procrastination on academic stress, subjective well-being, and academic achievement in secondary education

The main objective of this study was to test a structural theoretical model of the effects of self-regulated learning on academic stress, subjective well-being, and academic achievement in Secondary Education, considering academic procrastination as a mediator. An additional aim was to explore whether these relationships were moderated by gender and educational level. Participants were 728 students in compulsory and post-compulsory secondary education in a large city in Eastern Spain. Path analysis results indicated that the proposed model showed satisfactory fit, with the three dimensions of self-regulated learning significantly predicting the educational outcomes considered, and that procrastination mediated these relationships. Overall, the model is able to predict 9.8% of the variance of academic stress, 23.1% of students wellbeing, and 14% of academic achievement. Moreover, the multi-group routine revealed no moderation effects due to gender, but educational level moderated two relationships, between self-efficacy and academic achievement and between metacognitive strategies and procrastination. Additionally, supplementary models were tested for three specific subjects (Spanish Language, Foreign Language and Mathematics), which showed an improvement in explained variance, being respectively: 29%, 28% and 27%. Results are discussed in light of previous research and in terms of their impact on educational practice.

Metabolic determinants of stemness in medulloblastoma

Medulloblastomas (MBs) are the most prevalent brain tumours in children. They are classified as grade IV, the highest in malignancy, with about 30% metastatic tumours at the time of diagnosis. Cancer stem cells (CSCs) are a small subset of tumour cells that can initiate and support tumour growth. In MB, CSCs contribute to tumour initiation, metastasis, and therapy resistance. Metabolic differences among the different MB groups have started to emerge. Sonic hedgehog tumours show enriched lipid and nucleic acid metabolism pathways, whereas Group 3 MBs upregulate glycolysis, gluconeogenesis, glutamine anabolism, and glutathione-mediated anti-oxidant pathways. Such differences impact the clinical behaviour of MB tumours and can be exploited therapeutically. In this review, we summarise the existing knowledge about metabolic rewiring in MB, with a particular focus on MB-CSCs. Finally, we highlight some of the emerging metabolism-based therapeutic strategies for MB.

El impacto de la soledad y la fragilidad en el bienestar de los mayores europeos

Introducción: El bienestar es un constructo importante cuyos determinantes asociados deben ser identificados para comprender con mayor profundidad los procesos para envejecer de forma saludable. El estudio del impacto de la fragilidad en el bienestar de las personas mayores requiere incorporar los dominios físico, psicológico y social. Así, el adulto mayor frágil puede definirse a partir de la fragilidad física, junto con la soledad como fragilidad social. Este estudio propone un modelo para estudiar el impacto de la fragilidad física y la soledad sobre el bienestar de las personas mayores, diferenciando entre control, autonomía, placer y autorrealización. Métodos: Se realizó un estudio de carácter transversal con una muestra de 13569 personas mayores provenientes de la encuesta SHARE, para estimar un modelo de ecuaciones estructurales en el que se contemplaban los efectos de la fragilidad y la soledad en el bienestar (cuestionario CASP), controlado por el género, la edad y la salud percibida. Resultados: El modelo final contemplaba el efecto del género sobre el indicador de fuerza de prensión de fragilidad. Los resultados mostraron un ajuste adecuado del modelo a los datos y consiguieron explicar un 80.1% de la varianza de control, un 48.6% de la de autonomía, un 43.6% de la de placer y un 61.3% de la varianza de autorrealización. Conclusiones: La soledad y la fragilidad presentaron efectos diferenciales en función del componente de bienestar. Se discuten las implicaciones de dichos efectos en el desarrollo de intervenciones.

Glucose and Amino Acid Metabolic Dependencies Linked to Stemness and Metastasis in Different Aggressive Cancer Types

Malignant cells are commonly characterised by being capable of invading tissue, growing self-sufficiently and uncontrollably, being insensitive to apoptosis induction and controlling their environment, for example inducing angiogenesis. Amongst them, a subpopulation of cancer cells, called cancer stem cells (CSCs) shows sustained replicative potential, tumor-initiating properties and chemoresistance. These characteristics make CSCs responsible for therapy resistance, tumor relapse and growth in distant organs, causing metastatic dissemination. For these reasons, eliminating CSCs is necessary in order to achieve long-term survival of cancer patients. New insights in cancer metabolism have revealed that cellular metabolism in tumors is highly heterogeneous and that CSCs show specific metabolic traits supporting their unique functionality. Indeed, CSCs adapt differently to the deprivation of specific nutrients that represent potentially targetable vulnerabilities. This review focuses on three of the most aggressive tumor types: pancreatic ductal adenocarcinoma (PDAC), hepatocellular carcinoma (HCC) and glioblastoma (GBM). The aim is to prove whether CSCs from different tumour types share common metabolic requirements and responses to nutrient starvation, by outlining the diverse roles of glucose and amino acids within tumour cells and in the tumour microenvironment, as well as the consequences of their deprivation. Beyond their role in biosynthesis, they serve as energy sources and help maintain redox balance. In addition, glucose and amino acid derivatives contribute to immune responses linked to tumourigenesis and metastasis. Furthermore, potential metabolic liabilities are identified and discussed as targets for therapeutic intervention.

Lipid droplets as metabolic determinants for stemness and chemoresistance in cancer

Previously regarded as simple fat storage particles, new evidence suggests that lipid droplets (LDs) are dynamic and functional organelles involved in key cellular processes such as membrane biosynthesis, lipid metabolism, cell signalling and inflammation. Indeed, an increased LD content is one of the most apparent features resulting from lipid metabolism reprogramming necessary to support the basic functions of cancer cells. LDs have been associated to different cellular processes involved in cancer progression and aggressiveness, such as tumorigenicity, invasion and metastasis, as well as chemoresistance. Interestingly, all of these processes are controlled by a subpopulation of highly aggressive tumoral cells named cancer stem cells (CSCs), suggesting that LDs may be fundamental elements for stemness in cancer. Considering the key role of CSCs on chemoresistance and disease relapse, main factors of therapy failure, the design of novel therapeutic approaches targeting these cells may be the only chance for long-term survival in cancer patients. In this sense, their biology and functional properties render LDs excellent candidates for target discovery and design of combined therapeutic strategies. In this review, we summarise the current knowledge identifying LDs and CSCs as main contributors to cancer aggressiveness, metastasis and chemoresistance.

Quality of Life in European Older Adults of SHARE Wave 7: Comparing the Old and the Oldest-Old

CASP-12 (Control, Autonomy, Self-realization, and Pleasure scale) is one of the most common internationally used measures for quality of life in older adults, although its structure is not clearly established. Current research aims to test the factor structure of the CASP-12, so as to provide evidence on reliability and external validity, and to test for measurement invariance across age groups. Data from 61,355 Europeans (≥60 years old) from the Survey of Health, Ageing and Retirement in Europe wave 7 were used. CASP-12, EURO-D (European depression scale), self-perceived health, and life satisfaction measurements were included. Reliability and validity coefficients, competing confirmatory factor models, and standard measurement invariance routine were estimated. A second-order factor model with the original factor structure was retained. The scale showed adequate reliability coefficients except for the autonomy dimension. The correlation coefficients for external validity were all statistically significant. Finally, CASP-12 is scalar invariant across age. We conclude that the best-fitting factor structure retained allows using CASP-12 either by factors, or as an overall score, depending on the research interests. Findings related to CASP-12 measurement invariance encourage its use in the oldest-old too. When comparing the dimensions across age groups, as people age, autonomy slightly increases and the rest of the dimensions decline.

Inhibition of Mitochondrial Dynamics Preferentially Targets Pancreatic Cancer Cells with Enhanced Tumorigenic and Invasive Potential

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest tumors, partly due to its intrinsic aggressiveness, metastatic potential, and chemoresistance of the contained cancer stem cells (CSCs). Pancreatic CSCs strongly rely on mitochondrial metabolism to maintain their stemness, therefore representing a putative target for their elimination. Since mitochondrial homeostasis depends on the tightly controlled balance between fusion and fission processes, namely mitochondrial dynamics, we aim to study this mechanism in the context of stemness. In human PDAC tissues, the mitochondrial fission gene DNM1L (DRP1) was overexpressed and positively correlated with the stemness signature. Moreover, we observe that primary human CSCs display smaller mitochondria and a higher DRP1/MFN2 expression ratio, indicating the activation of the mitochondrial fission. Interestingly, treatment with the DRP1 inhibitor mDivi-1 induced dose-dependent apoptosis, especially in CD133+ CSCs, due to the accumulation of dysfunctional mitochondria and the subsequent energy crisis in this subpopulation. Mechanistically, mDivi-1 inhibited stemness-related features, such as self-renewal, tumorigenicity, and invasiveness and chemosensitized the cells to the cytotoxic effects of Gemcitabine. In summary, mitochondrial fission is an essential process for pancreatic CSCs and represents an attractive target for designing novel multimodal treatments that will more efficiently eliminate cells with high tumorigenic potential.

Glutathione metabolism is essential for self-renewal and chemoresistance of pancreatic cancer stem cells

BACKGROUND

Cellular metabolism regulates stemness in health and disease.  A reduced redox state is essential for self-renewal of normal and cancer stem cells (CSCs). However, while stem cells rely on glycolysis, different CSCs, including pancreatic CSCs, favor mitochondrial metabolism as their dominant energy-producing pathway. This suggests that powerful antioxidant networks must be in place to detoxify mitochondrial reactive oxygen species (ROS) and maintain stemness in oxidative CSCs. Since glutathione metabolism is critical for normal stem cell function and CSCs from breast, liver and gastric cancer show increased glutathione content, we hypothesized that pancreatic CSCs also rely on this pathway for ROS detoxification.

AIM

To investigate the role of glutathione metabolism in pancreatic CSCs.

METHODS

Primary pancreatic cancer cells of patient-derived xenografts (PDXs) were cultured in adherent or CSC-enriching sphere conditions to determine the role of glutathione metabolism in stemness. Real-time polymerase chain reaction (PCR) was used to validate RNAseq results involving glutathione metabolism genes in adherent vs spheres, as well as the expression of pluripotency-related genes following treatment. Public TCGA and GTEx RNAseq data from pancreatic cancer vs normal tissue samples were analyzed using the webserver GEPIA2. The glutathione-sensitive fluorescent probe monochlorobimane was used to determine glutathione content by fluorimetry or flow cytometry. Pharmacological inhibitors of glutathione synthesis and recycling [buthionine-sulfoximine (BSO) and 6-Aminonicotinamide (6-AN), respectively] were used to investigate the impact of glutathione depletion on CSC-enriched cultures. Staining with propidium iodide (cell cycle), Annexin-V (apoptosis) and CD133 (CSC content) were determined by flow cytometry. Self-renewal was assessed by sphere formation assay and response to gemcitabine treatment was used as a readout for chemoresistance.

RESULTS

Analysis of our previously published RNAseq dataset E-MTAB-3808 revealed up-regulation of genes involved in the KEGG (Kyoto Encyclopedia of Genes and Genomes) Pathway Glutathione Metabolism in CSC-enriched cultures compared to their differentiated counterparts. Consistently, in pancreatic cancer patient samples the expression of most of these up-regulated genes positively correlated with a stemness signature defined by NANOG, KLF4, SOX2 and OCT4 expression (P < 10^-5). Moreover, 3 of the upregulated genes (MGST1, GPX8, GCCT) were associated with reduced disease-free survival in patients [Hazard ratio (HR) 2.2-2.5; P = 0.03-0.0054], suggesting a critical role for this pathway in pancreatic cancer progression. CSC-enriched sphere cultures also showed increased expression of different glutathione metabolism-related genes, as well as enhanced glutathione content in its reduced form (GSH). Glutathione depletion with BSO induced cell cycle arrest and apoptosis in spheres, and diminished the expression of stemness genes. Moreover, treatment with either BSO or the glutathione recycling inhibitor 6-AN inhibited self-renewal and the expression of the CSC marker CD133. GSH content in spheres positively correlated with intrinsic resistance to gemcitabine treatment in different PDXs r = 0.96, P = 5.8 × 10¹¹). Additionally, CD133⁺ cells accumulated GSH in response to gemcitabine, which was abrogated by BSO treatment (P < 0.05). Combined treatment with BSO and gemcitabine-induced apoptosis in CD133⁺ cells to levels comparable to CD133^- cells and significantly diminished self-renewal (P < 0.05), suggesting that chemoresistance of CSCs is partially dependent on GSH metabolism.

CONCLUSION

Our data suggest that pancreatic CSCs depend on glutathione metabolism. Pharmacological targeting of this pathway showed that high GSH content is essential to maintain CSC functionality in terms of self-renewal and chemoresistance.

Exploiting oxidative phosphorylation to promote the stem and immunoevasive properties of pancreatic cancer stem cells

Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of cancer death, has a 5-year survival rate of approximately 7-9%. The ineffectiveness of anti-PDAC therapies is believed to be due to the existence of a subpopulation of tumor cells known as cancer stem cells (CSCs), which are functionally plastic, and have exclusive tumorigenic, chemoresistant and metastatic capacities. Herein, we describe a 2D in vitro system for long-term enrichment of pancreatic CSCs that is amenable to biological and CSC-specific studies. By changing the carbon source from glucose to galactose in vitro, we force PDAC cells to utilize OXPHOS, resulting in enrichment of CSCs defined by increased CSC biomarker and pluripotency gene expression, greater tumorigenic potential, induced but reversible quiescence, increased OXPHOS activity, enhanced invasiveness, and upregulated immune evasion properties. This CSC enrichment method can facilitate the discovery of new CSC-specific hallmarks for future development into targets for PDAC-based therapies.

Measurement of the will to live in older adults: Transcultural adaptation, validity and reliability of the Will-to-Live Scale

OBJECTIVE

The Will-to-Live Scale (WTLS) is used to measure the will to live in older adults; however, there is no Spanish version. The objective of the study was to translate the WTLS into Spanish, assess its internal structure, reliability, and the correlates between WTLS and life satisfaction, resilience, and depression in older Peruvian adults.

METHOD

The participants were 235 Peruvian older adults (M=72.69, SD=6.68), evaluated between March to May 2019, selected through non-probability sampling. The WTLS, the Satisfaction with Life Scale (SWLS), the Brief Resilient Coping Scale (BRCS) and the Patient Health Questionnaire-2 (PHQ-2) were administered. Data analysis included reliability by internal consistency and structural equation models, specifically confirmatory factor analysis (AFC), to test the one-dimensional solution of the WTLS and the convergent validity of the WTLS at the latent level, by specifying a four-factor model (will to live, life satisfaction, resilience and depression).

RESULTS

Cronbach's alpha coefficient and the composite reliability index obtain values of .93 and .94, respectively. The one-dimensional structure of the WTLS was fitted to the data (χ²₍₅₎=10,067, P=.073, CFI=.999, RMSEA=.066, SRMR=.014) and showed positive associations with the SWLS (ρ=.82), and BRCS (ρ=.86), as well as negative associations with the PHQ-2 (ρ=-.66).

CONCLUSION

The WTLS in Spanish presents evidence of validity and reliability to measure the will to live in Peruvian older adults.

Erratum: Pérez-Belmonte, S., et al. Subtypes of Depression: Latent Class Analysis in Spanish Old People with Depressive Symptoms. Life 2020, 10, 70

The authors wish to make the following erratum to this paper [...].

ISG15 and ISGylation is required for pancreatic cancer stem cell mitophagy and metabolic plasticity

Pancreatic cancer stem cells (PaCSCs) drive pancreatic cancer tumorigenesis, chemoresistance and metastasis. While eliminating this subpopulation of cells would theoretically result in tumor eradication, PaCSCs are extremely plastic and can successfully adapt to targeted therapies. In this study, we demonstrate that PaCSCs increase expression of interferon-stimulated gene 15 (ISG15) and protein ISGylation, which are essential for maintaining their metabolic plasticity. CRISPR-mediated ISG15 genomic editing reduces overall ISGylation, impairing PaCSCs self-renewal and their in vivo tumorigenic capacity. At the molecular level, ISG15 loss results in decreased mitochondrial ISGylation concomitant with increased accumulation of dysfunctional mitochondria, reduced oxidative phosphorylation (OXPHOS) and impaired mitophagy. Importantly, disruption in mitochondrial metabolism affects PaCSC metabolic plasticity, making them susceptible to prolonged inhibition with metformin in vivo. Thus, ISGylation is critical for optimal and efficient OXPHOS by ensuring the recycling of dysfunctional mitochondria, and when absent, a dysregulation in mitophagy occurs that negatively impacts PaCSC stemness.

The ubiquitin-like modifier ISG15 exerts post-translational protein regulation through ISGylation. Here, the authors show that ISGylation is necessary for pancreatic cancer stem cell self-renewal and tumourigenesis by supporting the recycling of non-functional mitochondria.

Subtypes of Depression: Latent Class Analysis in Spanish Old People with Depressive Symptoms

Major depressive disorder (MDD) is one of the most disabling disorders and the one that most contributes to disability. When it occurs in older people, it is an additional burden to their potential physical and cognitive deficiencies, making MDD an important public health problem that supposes a large investment in health. There is a clear lack of consistency between the subtypes of depression found in the literature, ranging from two to seven classes, with three being the most commonly found non-melancholic, melancholic and psychotic, or putative psychotics. The aim of this research is to add knowledge to the profiles of depressive symptoms in a representative sample of older Spanish people, and to study the possible relationship of these symptom profiles with variables that have traditionally been related to depression. Spanish data from the sixth wave of SHARE were used, with 612 Spanish older adults living in Spain. A routine of several LCAs with a different number of classes was performed to answer this first aim to classify Spanish adults with depression symptoms. The results pointed out the presence of three different classes among the participants in the study: psychosomatic (11.12%), melancholic (14.21%), and anhedonic (74.67%). This work represents a step forward to understand the heterogeneity of major depressive disorder, facilitating the diagnosis, and subsequent treatment of older adults.

Cancer associated fibroblast FAK regulates malignant cell metabolism

Emerging evidence suggests that cancer cell metabolism can be regulated by cancer-associated fibroblasts (CAFs), but the mechanisms are poorly defined. Here we show that CAFs regulate malignant cell metabolism through pathways under the control of FAK. In breast and pancreatic cancer patients we find that low FAK expression, specifically in the stromal compartment, predicts reduced overall survival. In mice, depletion of FAK in a subpopulation of CAFs regulates paracrine signals that increase malignant cell glycolysis and tumour growth. Proteomic and phosphoproteomic analysis in our mouse model identifies metabolic alterations which are reflected at the transcriptomic level in patients with low stromal FAK. Mechanistically we demonstrate that FAK-depletion in CAFs increases chemokine production, which via CCR1/CCR2 on cancer cells, activate protein kinase A, leading to enhanced malignant cell glycolysis. Our data uncover mechanisms whereby stromal fibroblasts regulate cancer cell metabolism independent of genetic mutations in cancer cells.

Mitochondrial determinants of chemoresistance

Chemoresistance constitute nowadays the major contributor to therapy failure in most cancers. There are main factors that mitigate cell response to therapy, such as target organ, inherent sensitivity to the administered compound, its metabolism, drug efflux and influx or alterations on specific cellular targets, among others. We now know that intrinsic properties of cancer cells, including metabolic features, substantially contribute to chemoresistance. In fact, during the last years, numerous reports indicate that cancer cells resistant to chemotherapy demonstrate significant alterations in mitochondrial metabolism, membrane polarization and mass. Metabolic activity and expression of several mitochondrial proteins are modulated under treatment to cope with stress, making these organelles central players in the development of resistance to therapies. Here, we review the role of mitochondria in chemoresistant cells in terms of metabolic rewiring and function of key mitochondria-related proteins.

Does the Spanish version of the SWLS measure the same in Spain and Peru?

AIM

Satisfaction with life is a measure of protection in older adults. There lies the importance of providing quality instruments. The aim of the study was to evaluate the invariance of the life satisfaction scale (SWLS) in two samples of older adults in Spain and Peru.

METHOD

The participants were 857 older adults in Spain (mean age=68.23 years, SD=5.93) and 336 older adults in Peru (average age=72.42, SD=7.07). All multi-group confirmatory factor analyzes were estimated in Mplus 8.0.

RESULTS

The results indicate the presence of a strict invariance of the one-dimensional structure of the SWLS in samples of older adults in Spain and Peru, which allows for meaningful comparisons of latent means and covariances. Comparison of latent means showed small differences in the construct between the cultural groups.

CONCLUSIONS

The SWLS is a valid instrument for intercultural comparisons between Spanish and Peruvian population. The measurement invariance assessment contributes to a better understanding of life satisfaction in populations from different cultural contexts.

Metabolism-Based Therapeutic Strategies Targeting Cancer Stem Cells

Cancer heterogeneity constitutes the major source of disease progression and therapy failure. Tumors comprise functionally diverse subpopulations, with cancer stem cells (CSCs) as the source of this heterogeneity. Since these cells bear in vivo tumorigenicity and metastatic potential, survive chemotherapy and drive relapse, its elimination may be the only way to achieve long-term survival in patients. Thanks to the great advances in the field over the last few years, we know now that cellular metabolism and stemness are highly intertwined in normal development and cancer. Indeed, CSCs show distinct metabolic features as compared with their more differentiated progenies, though their dominant metabolic phenotype varies across tumor entities, patients and even subclones within a tumor. Following initial works focused on glucose metabolism, current studies have unveiled particularities of CSC metabolism in terms of redox state, lipid metabolism and use of alternative fuels, such as amino acids or ketone bodies. In this review, we describe the different metabolic phenotypes attributed to CSCs with special focus on metabolism-based therapeutic strategies tested in preclinical and clinical settings.

More on the Dimensionality of the GHQ-12: Competitive Confirmatory Models

The General Health Questionnaire (GHQ) was designed to measure minor psychiatric morbidity by assessing normal ‘healthy’ functioning and the appearance of new, distressing symptoms. Among its versions, the 12-item is one of the most used. GHQ-12’s validity and reliability have been extensively tested in samples from different populations. In the Spanish version, studies have come to different conclusions, of one, two, and three-factor structures. This research aims to present additional evidence on the factorial validity of the Spanish version of the GHQ-12, using competitive confirmatory models. Three samples of workers (N= 525, 414 and 540) were used to test a set of substantive models previously found in Spanish and international literature. Results showed that multidimensional models had moderate to substantial inter-factor correlations (ranging from 0.29 to 0.76) but not as high as to jeopardize their discriminant validity. The best-fitting models were the original solution by Graetz (1991) and the exploratory three-factor solution offered by Rocha et al. (2011), multidimensional three-factor solutions with correlated factors. The conclusion is that a multidimensional three-factor structure underlies the items in the GHQ-12.

Autonomy Support, Psychological Needs Satisfaction, School Engagement and Academic Success: A Mediation Model

School engagement is a construct of relevance in education and educational psychology, as it has been related to multiple educational constructs and outcomes: school drop-out, satisfaction with school, disruptive behavior, motivational climate, teacher-student relationships, or academic progress and achievement. The current research surveyed 2034 Angolan students and 2302 Dominican Republic students in order to predict academic achievement. The model tested was supported by the data in both samples, and the chain of explicative effects hold again in both samples. School engagement was a powerful mediator among needs satisfaction and academic success. Results are discussed in light of existing literature, and limitations and future directions of research are also highlighted.

Active surveillance as a successful management strategy for patients with clinical stage I germ cell testicular cancer

BACKGROUND

Cancer-specific survival for patients with clinical stage I (CSI) germ cell testicular cancer (GCTC) is outstanding after inguinal orchidectomy regardless the treatment utilized. This study evaluated whether active surveillance (AS) of such patients yielded similar health outcomes to other therapeutic strategies such as adjuvant chemotherapy, radiotherapy or primary retroperitoneal lymphadenectomy as described in the literature.

PATIENTS AND METHODS

Patients with CSI GCTC were screened between January 2012 and December 2016. Patients had previously undergone inguinal orchidectomy as the primary treatment and chosen AS as their preferred management strategy after receiving information about all available strategies.

RESULTS

Out of 91 patients screened, 82 patients selected AS as their preferred management strategy. Relapse rate in the overall population was 20% (95% CI 12-30) and median time to relapse was 11.5 months (range 1.0-35.0). In patients with seminomatous tumors, relapse rate decreased to 13% and median time to relapse was 13 months; whereas in patients with non-seminomatous tumors, relapse rate was 33% (IA) or 29% (IB) and median time to relapse was 12 months in stage IA and 4.5 months in stage IB patients. All relapses were rescued with three or four cycles of chemotherapy and two also required a retroperitoneal lymphadenectomy. All patients are currently alive and free of disease.

CONCLUSIONS

The clinical outcomes of patients with CSI GCTC managed by AS in this series were excellent. This strategy limited the administration of active treatments specifically to the minority of patients who relapsed without compromising performance.

Oral health in Alzheimer's disease: a multicenter case-control study

OBJECTIVES

The aim of this case-control study was to carry out an oral health assessment on a group of Alzheimer's patients and to establish a hypothesis regarding the implication of the characteristics of the disease and the treatment of oral health.

MATERIALS AND METHODS

A total of 70 Alzheimer's patients, residents at the Alzheimer Center Reina Sofia Foundation (Madrid, Spain) and at the Alzheimer State Reference Center (Salamanca, Spain), and 36 controls (companions/acquaintances), were studied by oral examination and saliva sampling. The oral health indices DMFT/DMFS, CPI, the prosthetic condition, oral hygiene, saliva volume, and pH, as well as the specific microbiological parameters governing the risk of developing caries were assessed.

RESULTS

Alzheimer's patients exhibited, as compared to the control group, (1) fewer teeth (10.9 ± 10.5 vs 23.7 ± 6.5), (2) fewer obturations (2.2 ± 3.4 vs 6.6 ± 5.6), (3) fewer periodontally healthy sextants (0.1 ± 0.4 vs 1.4 ± 2.2), (4) worse oral hygiene (43.1 vs 72.2% brushed), (5) greater use of removable prostheses (47.8 vs 8.4%), (6) higher incidence of candida infection (11.8 vs 0.0%) and cheilitis (15.9 vs 0.0%), (7) lower salivary flow (0.6 ± 0.6 vs 1.1 ± 0.6), and (8) lower buffering capacity (46 vs 80%).

CONCLUSIONS

After taking into account the influence of age, Alzheimer's patients had worse oral health (caries and periodontal disease), more mucosal lesions (cheilitis and candidiasis), and worse saliva quantity and quality.

CLINICAL RELEVANCE

Clinicians should be aware of the implications of Alzheimer's disease in oral health, in order to stablish the effective preventive measures and the optimal treatment plan.

Factorial Validity of the General Health Questionnaire 12 in an Angolan Sample

Abstract. Most evidence available has found multidimensional solutions for the General Health Questionnaire’s (GHQ12) structure, contrary to the authors’ original one-factor solution. Recently, the study of method effects associated to negatively worded items has been included in the study of GHQ12’s factor structure, and the most common conclusion has been that the best-fitting structure is a single factor confounded by response bias. Current study analyzes the factor structure of the Portuguese version of the GHQ12. The sample consisted of 1,332 young Angolan adults. Previously-reported structures, including one-factor and multidimensional substantive ones, as well as bifactor structures, and models positing method effects among negatively worded items were tested via Confirmatory Factor Analyses. Results suggested that a three substantive factor solution adequately represented the scale’s underlying structure. The emerging factors were dysphoria, social dysfunction, and loss of confidence. Method effects did not play a clear role in explaining the multidimensionality observed in the factor structures tested for the GHQ12.

Predicción del bienestar hedónico y eudaimónico en envejecimiento con éxito

El bienestar psicológico es un constructo de la máxima importancia en psicología, siendo el equivalente a la salud en términos médicos. Es un concepto multifacético. Que ha dado lugar a dos tradiciones, la hedónica y la eudaimónica. Por otro lado, un marco teórico útil en el que enmarcar un envejecimiento óptimo es el paradigma del envejecimiento con éxito. Rowe y Kahn (1998) articularon este paradigma proponiendo un modelo con tres características principales: salud física, función cognitiva y estar activo en términos de actividades productivas y relaciones sociales. El objetivo de este trabajo es ofrecer un modelo predictivo del bienestar, tanto hedónico como eudaimónico, empleando para ello el paradigma del envejecimiento con éxito y adicionalmente un componente de espiritualidad. Los resultados más relevantes de este modelo muestran que el apoyo social presentó un impacto relevante y positivo sobre la satisfacción y algo menor sobre el bienestar. La salud física también juega un papel relevante, especialmente al predecir satisfacción. La espiritualidad también tiene un papel protector sobre el bienestar. El porcentaje de varianza explicado de la satisfacción vital fue un 23.3%, y un 10.4% sobre bienestar.

[Aging and spirituality: Factorial structure and reliability of 2 scales]

INTRODUCTION

In the field of gerontology, the study of the improvement of health and quality of life, and «successfully aging», spirituality plays a key role and, is one of the current research approaches. However, its incorporation into scientific literature is arduous and slow, a fact that is in part due to the absence of developed and validated measurement tools, particularly, in the Spanish speaking area. This work aims to present evidence of the psychometric properties of two tools for the measurement of spirituality: the Functional Assessment of Chronic Illness Therapy Spiritual Well-Being (FACIT-Sp) and the GES Questionnaire.

MATERIALS AND METHODS

A sample of 224 elderly persons from Valencia (Spain) was recruited, on which two confirmatory factor analyses were estimated, with the proposed a priori structures for each tool, together with several reliability coefficients.

RESULTS

Both models presented an good fit to the data: χ(2)51=104.97 (P<.01); CFI=.973; RMSEA=.076 for the FACIT-Sp, and χ(2)17=31.76 (P>.05); CFI=.996; RMSEA=.050 for the GES Questionnaire. Reliability indices also supported the use of the scales in elderly population, with alphas of .85 and .86, respectively.

CONCLUSIONS

These results may be useful as a starting point to include spirituality in works that aim to discover the mechanisms involved in successful aging.

The ever-changing landscape of pancreatic cancer stem cells

Over the past decade, the cancer stem cell (CSC) concept in solid tumors has gained enormous momentum as an attractive model to explain tumor heterogeneity. The model proposes that tumors contain a subpopulation of rare cancer cells with stem-like properties that maintain the hierarchy of the tumor and drive tumor initiation, progression, metastasis, and chemoresistance. The identification and subsequent isolation of CSCs in pancreatic ductal adenocarcinoma (PDAC) in 2007 provided enormous insight into this extremely metastatic and chemoresistant tumor and renewed hope for developing more specific therapies against this disease. Unfortunately, we have made only marginal advances in applying the knowledge learned to the development of new and more effective treatments for pancreatic cancer. The latter has been partly due to the lack of adequate in vitro and in vivo systems compounded by the use of markers that do not reproducibly nor exclusively select for an enriched CSC population. Thus, attempts to define a pancreatic CSC-specific genetic, epigenetic or proteomic signature has been challenging. Fortunately recent advances in the CSC field have overcome many of these challenges and have opened up new opportunities for developing therapies that target the CSC population. In this review, we discuss these current advances, specifically new methods for the identification and isolation of pancreatic CSCs, new insights into the metabolic profile of CSCs at the level of mitochondrial respiration, and the utility of genetically engineered mouse models as surrogate systems to both study CSC biology and evaluate CSC-specific targeted therapies in vivo.

Socio-Demographic Variables and Successful Aging of the Angolan Elderly

The proportion of elderly people is growing faster than any other age group. Amongst them, the group of oldest old is indeed the segment of the elderly population with the fastest growth rate. The increase in the proportion of elderly in the Angolan population makes research on this area badly needed. Within the theoretical framework of successful aging, the study aims to test for sociodemographic group differences in perceived health, life satisfaction, and social relations in Angolan elderly. The dependent variables are three of the components of what has been called successful aging. Data came from a cross-sectional survey of elderly people living in Luanda. 1003 Angolan elderly were surveyed on sociodemographic information, perceived health, life satisfaction, and social support. MANOVAs were calculated to test for mean differences in the dependent variables. Results permit to conclude that the factors associated with the largest differences on the Angolan elderly's quality of life and social relations were age (becoming oldest old) and institutionalization. The interactions of several factors with age pointed out that the oldest old were clearly a group in which the decreased quality of life due to becoming oldest old could not be compensated by other factors, as it was the case in the group of young old.

More challenges ahead-metabolic heterogeneity of pancreatic cancer stem cells

Pancreatic cancer stem cells (CSCs) display a distinct metabolic phenotype based on their strong dependence on mitochondrial oxidative phosphorylation (OXPHOS) and limited metabolic plasticity. While suppression of MYC upstream of PGC-1α was the key determinant of this phenotype, we also identified a subset of CSCs with reduced mitochondrial content that showed resistance to mitochondrial targeting, but could be sensitized by inhibition of MYC.

Validación de un modelo explicativo del proceso de envejecer con éxito a partir de aspectos psicológicos, físicos, relacionales y de ocio

Cada vez más, la investigación sobre el proceso de envejecimiento tiende a adoptar una doble perspectiva emic (específico a una cultura) y etic (universal), necesitándose más estudios que atiendan un enfoque transcultural. El objetivo es obtener respuesta empírica a la pregunta de si un modelo de envejecimiento con éxito planteado desde un contexto diferente como es el taiwanés, es adecuado para representar este proceso en nuestros mayores. La muestra estuvo formada por 737 personas mayores. Se recabaron datos de variables socio-demográficas y diversas escalas para evaluar satisfacción con la vida, ocio, salud y apoyo social. Se puso a prueba un modelo de ecuaciones estructurales tomado de Lee et al. (2011), en el que ocio, salud y apoyo social predecían satisfacción con la vida. Los resultados obtenidos mostraron un ajuste adecuado. En concreto, se observó que, en el marco de otros factores que teóricamente influyentes -salud y apoyo social-, este novedoso aspecto sobre cómo las personas mayores gestionan su tiempo de ocio, aunque explicativo, no es un factor tan determinante como en el estudio de referencia.

Microenvironmental hCAP-18/LL-37 promotes pancreatic ductal adenocarcinoma by activating its cancer stem cell compartment

OBJECTIVES

The tumour stroma/microenvironment not only provides structural support for tumour development, but more importantly it provides cues to cancer stem cells (CSCs) that regulate their self-renewal and metastatic potential. This is certainly true for pancreatic ductal adenocarcinomas (PDAC), where tumour-associated fibroblasts, pancreatic stellate cells and immune cells create an abundant paracrine niche for CSCs via microenvironment-secreted factors. Thus understanding the role that tumour stroma cells play in PDAC development and CSC biology is of utmost importance.

DESIGN

Microarray analyses, tumour microarray immunohistochemical assays, in vitro co-culture experiments, recombinant protein treatment approaches and in vivo intervention studies were performed to understand the role that the immunomodulatory cationic antimicrobial peptide 18/LL-37 (hCAP-18/LL-37) plays in PDAC biology.

RESULTS

We found that hCAP-18/LL-37 was strongly expressed in the stroma of advanced primary and secondary PDAC tumours and is secreted by immune cells of the stroma (eg, tumour-associated macrophages) in response to tumour growth factor-β1 and particularly CSC-secreted Nodal/ActivinA. Treatment of pancreatic CSCs with recombinant LL-37 increased pluripotency-associated gene expression, self-renewal, invasion and tumourigenicity via formyl peptide receptor 2 (FPR2)- and P2X purinoceptor 7 receptor (P2X7R)-dependent mechanisms, which could be reversed by inhibiting these receptors. Importantly, in a genetically engineered mouse model of K-Ras-driven pancreatic tumourigenesis, we also showed that tumour formation was inhibited by either reconstituting these mice with bone marrow from cathelicidin-related antimicrobial peptide (ie, murine homologue of hCAP-18/LL-37) knockout mice or by pharmacologically inhibiting FPR2 and P2X7R.

CONCLUSIONS

Thus, hCAP-18/LL-37 represents a previously unrecognised PDAC microenvironment factor that plays a critical role in pancreatic CSC-mediated tumourigenesis.

Propiedades psicométricas de la versión española de la Escala Temporal de Satisfacción con la Vida (Temporal Satisfaction With Life Scale, TSLS): Un estudio en mayores que acuden a programas universitarios

Para la operacionalización del bienestar se han desarrollado un gran número de medidas, destacando la Escala de Satisfacción con la Vida (SWLS). Para paliar algunos de sus problemas, se desarrolló la Escala Temporal de Satisfacción con la Vida (TSLS). El objetivo de este estudio es la presentación y primera validación de la TSLS en su versión española, en una muestra de personas mayores que acuden a programas universitarios. La muestra estaba formada por 737 personas mayores. Además de la TSLS, se empleó un indicador de satisfacción general con la vida y la SF-8. Los análisis incluyeron estudio de la validez factorial, estimaciones de la fiabilidad y de validez externa. Los resultados del análisis factorial confirmatorio fueron adecuados: χ2 (87) = 454.593 (p < .001), CFI = .973; RMSEA = .085, mostrando la adecuación del modelo de tres dimensiones propuesto. La consistencia interna de las tres dimensiones fue alta: alfas de .83 para la satisfacción con la vida pasada, .81 para la presente y .86 para la futura. También los resultados de validez externa fueron los esperados. La TSLS incorpora el eje temporal en la medida de la satisfacción con la vida, con garantías psicométricas. Sus utilidades se comentan en la discusión.

Validation of an explicative model of the successful aging process with psychological, physical, relational, and leisure variables

Increasingly, research on the aging process tends to adopt a dual perspective emic (specific to a culture) and etic (universal), requiring further studies to address this cross-cultural approach. The aim is to obtain an empirical answer to the question of whether a model of successful aging raised from a different context such as the Taiwanese context, is suitable to represent this process in our elders. The sample consisted of 737 elderly. Socio-demographic-data and different scales to assess life satisfaction, leisure, health, and social support were collected. A structural equation model taken from Lee et al. (2011), in which leisure, health and social support predicted life satisfaction, was tested. Results showed a proper fit. In particular, it was observed that, in the context of other factors theoretically influential -health and social support-, this new aspect of how older people manage their leisure time, although explanatory, is not such a determining factor as in the study of reference.

MYC/PGC-1α Balance Determines the Metabolic Phenotype and Plasticity of Pancreatic Cancer Stem Cells

The anti-diabetic drug metformin targets pancreatic cancer stem cells (CSCs), but not their differentiated progenies (non-CSCs), which may be related to distinct metabolic phenotypes. Here we conclusively demonstrate that while non-CSCs were highly glycolytic, CSCs were dependent on oxidative metabolism (OXPHOS) with very limited metabolic plasticity. Thus, mitochondrial inhibition, e.g., by metformin, translated into energy crisis and apoptosis. However, resistant CSC clones eventually emerged during treatment with metformin due to their intermediate glycolytic/respiratory phenotype. Mechanistically, suppression of MYC and subsequent increase of PGC-1α were identified as key determinants for the OXPHOS dependency of CSCs, which was abolished in resistant CSC clones. Intriguingly, no resistance was observed for the mitochondrial ROS inducer menadione and resistance could also be prevented/reversed for metformin by genetic/pharmacological inhibition of MYC. Thus, the specific metabolic features of pancreatic CSCs are amendable to therapeutic intervention and could provide the basis for developing more effective therapies to combat this lethal cancer.

Psychometric properties of the Spanish version of the Temporal Satisfaction with Life Scale (TSLS): A study on elderly attending to university programs

Several measures have been developed for the operalization of well-being, standing out the Satisfaction With Life Scale (SWLS). To cope with some of its problems the Temporal Satisfaction with Life Scale (TSLS) was developed. The aim of this study is to present and validate the Spanish version of the TSLS, in a sample elderly attending to University programs. The sample was composed of 737 elderly. Together with the TSLS, an indicator of general life satisfaction and the SF-8 Health Scale were used. Analyses included the study of factorial validity, estimations of reliability and external validity. Results of the confirmatory factor analysis were adequate: χ2(87)=454.593 (p<.001), CFI=.973; RMSEA=.085, showing appropriate fit for the three-dimension model posed. Internal consistency of the three dimensions was high: alpha values of .83 for past, .81 for present, and .86 for future life satisfaction. Additionally, results of external validity were as expected. The TSLS addresses the temporal axis in the measurement of life satisfaction, with psychometric guarantees. Its utilities are explained in the discussion.

Prediction of hedonic and eudaimonic well-being in succesful aging

Psychological well-being is a construct of maximum relevance in psychology, being the equivalent to health in medical sciences. It is a multifaceted construct, with two research traditions: the hedonic and the eudaimonic ones. On the other hand, the paradign of succesful aging is a good theoretical framework to study and understand optimal aging. Rowe and Kahn (1998) articulated this paradign proposing its three main characteristics: physcal health, cognitive functioning and being productive and socially active. The aim of this research is to develop a predictive model of well-being, both hedonic and eudaimonic, using the sucessful aging parading plus a dimension of spirituality. Main results of the model showed that social support had a significant and positive on satisfaction and to a lesser extent on well-being. Pshysical health was also a significant predictor of satisfaction. An finally, spirituality may also be considered a protector of well-being. Percentage of variance explained of life satisfaction was 23.3%, while this percentage on well-being was 10.4%.

TGF-beta signaling in cancer treatment

The transforming growth factor-beta (TGF-β ) belongs to a superfamily of cytokines that act on protein kinase receptors at the plasma membrane to induce a plethora of biological signals that regulate cell growth and death, differentiation, immune response, angiogenesis and inflammation. Dysregulation of its pathway contributes to a broad variety of pathologies, including cancer. TGF-β is an important regulatory tumor suppressor factor in epithelial cells, where it early inhibits proliferation and induces apoptosis. However, tumor cells develop mechanisms to overcome the TGF-β -induced suppressor effects. Once this occurs, cells may respond to this cytokine inducing other effects that contribute to tumor progression. Indeed, TGF-β induces epithelial-mesenchymal transition (EMT), a process that is favored in tumor cells and facilitates migration and invasion. Furthermore, TGF-β mediates production of mitogenic growth factors, which stimulate tumor proliferation and survival. Finally, TGF-β is a well known immunosuppressor and pro-angiogenic factor. Many studies have identified the overexpression of TGF-β 1 in various types of human cancer, which correlates with tumor progression, metastasis, angiogenesis and poor prognostic outcome. For these reasons, different strategies to block TGF-β pathway in cancer have been developed and they can be classified in: (1) blocking antibodies and ligand traps; (2) antisense oligos; (3) TβRII and/or ALK5 inhibitors; (4) immune response-based strategies; (5) other inhibitors of the TGF-β pathway. In this review we will overview the two faces of TGF-β signaling in the regulation of tumorigenesis and we will dissect how targeting the TGF-β pathway may contribute to fight against cancer.

Espiritualidad, esperanza y dependencia como predictores de la satisfacción vital y la percepción de salud: efecto moderador de ser muy mayor

Objetivo: analizar algunos predictores de la calidad de vida en personas mayores, diferenciando entre mayores jóvenes o muy mayores. Esto es, se estudia un potencial efecto moderador debido a ser muy mayor, dado que este sector de la población está en rápido crecimiento en todo el mundo. Materiales y métodos: estudio transversal analítico de encuesta a 224 personas mayores, en dos grupos diferenciales, menores de 75 años y 75 años o más, que viven en la ciudad de Valencia (España). Resultados: se ajustó un modelo estructural multimuestra donde las dimensiones de espiritualidad y la esperanza predicen dos indicadores de calidad de vida en personas mayores: satisfacción vital y percepción de salud. Se han encontrado relaciones estadísticamente significativas (p < 0,05) entre la espiritualidad y la esperanza, y los dos indicadores; especialmente potente es la predicción de la satisfacción vital. Asimismo, los resultados multimuestra indican que la fe juega un papel diferencial relevante en los muy mayores. Discusión: se ponen en relación los hallazgos con la literatura. Conclusiones: existe un importante impacto, en algunos casos diferencial para los muy mayores, de la espiritualidad sobre indicadores de envejecimiento con éxito tales como la satisfacción vital y la salud, y la capacidad para realizar actividades, ya sea instrumentales de la vida diaria, o en general todo tipo de actividades productivas.

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Nicotine promotes initiation and progression of KRAS-induced pancreatic cancer via Gata6-dependent dedifferentiation of acinar cells in mice

BACKGROUND & AIMS

Although smoking is a leading risk factor for pancreatic ductal adenocarcinoma (PDAC), little is known about the mechanisms by which smoking promotes initiation or progression of PDAC.

METHODS

We studied the effects of nicotine administration on pancreatic cancer development in Kras(+/LSLG12Vgeo);Elas-tTA/tetO-Cre (Ela-KRAS) mice, Kras(+/LSLG12D);Trp53+/LSLR172H;Pdx-1-Cre (KPC) mice (which express constitutively active forms of KRAS), and C57/B6 mice. Mice were given nicotine for up to 86 weeks to produce blood levels comparable with those of intermediate smokers. Pancreatic tissues were collected and analyzed by immunohistochemistry and reverse transcriptase polymerase chain reaction; cells were isolated and assayed for colony and sphere formation and gene expression. The effects of nicotine were also evaluated in primary pancreatic acinar cells isolated from wild-type, nAChR7a(-/-), Trp53(-/-), and Gata6(-/-);Trp53(-/-) mice. We also analyzed primary PDAC cells that overexpressed GATA6 from lentiviral expression vectors.

RESULTS

Administration of nicotine accelerated transformation of pancreatic cells and tumor formation in Ela-KRAS and KPC mice. Nicotine induced dedifferentiation of acinar cells by activating AKT-ERK-MYC signaling; this led to inhibition of Gata6 promoter activity, loss of GATA6 protein, and subsequent loss of acinar differentiation and hyperactivation of oncogenic KRAS. Nicotine also promoted aggressiveness of established tumors as well as the epithelial-mesenchymal transition, increasing numbers of circulating cancer cells and their dissemination to the liver, compared with mice not exposed to nicotine. Nicotine induced pancreatic cells to acquire gene expression patterns and functional characteristics of cancer stem cells. These effects were markedly attenuated in K-Ras(+/LSL-G12D);Trp53(+/LSLR172H);Pdx-1-Cre mice given metformin. Metformin prevented nicotine-induced pancreatic carcinogenesis and tumor growth by up-regulating GATA6 and promoting differentiation toward an acinar cell program.

CONCLUSIONS

In mice, nicotine promotes pancreatic carcinogenesis and tumor development via down-regulation of Gata6 to induce acinar cell dedifferentiation.

Mechanisms of resistance to apoptosis in the human acute promyelocytic leukemia cell line NB4

Current frontline therapies have improved overall survival in acute promyelocytic leukemia (APL) patients to exceptional rates; however, relapse is still a problem among high-risk and old patients. Therefore, the development of better and safer therapies continues to be a goal in the treatment of this disease. In the present work, we examined three different pathways that hinder cell death in the APL cell line NB4, shedding light on the mechanisms that underlie resistance to apoptosis in these cells and that might help provide them with a proliferative advantage. We found that the proteasome inhibitor MG-132 specifically induces in NB4 cells an Nrf2-mediated antioxidant response which counteracts mitochondria-dependent apoptosis induced by the lipophilic cation dequalinium. More importantly, we also demonstrated that high basal autophagy levels and the gain-of-function of mutant p53 are intrinsic mechanisms of resistance to apoptosis in this cell line. According to our results, the pharmacological inhibition of autophagy and p53 mutants are useful tools to explore resistance to apoptosis in APL and other types of cancer and could be the bases of new therapeutic approaches that improve the efficiency and allow dose reduction of the current treatments.

[Cost-consequence analysis of respiratory preventive intervention among institutionalized older people: randomized controlled trial]

INTRODUCTION

The institutionalized elderly with functional impairment show a greater decline in respiratory muscle (RM) function. The aims of the study are to evaluate outcomes and costs of RM training using Pranayama in institutionalized elderly people with functional impairment.

MATERIAL AND METHODS

A randomized controlled trial was conducted on institutionalized elderly people with walking limitation (n=54). The intervention consisted of 6 weeks of Pranayama RM training (5 times/week). The outcomes were measured at 4 time points, and were related to RM function: the maximum respiratory pressures and the maximum voluntary ventilation. Perceived satisfaction in the experimental group (EG) was assessed by means of an ad hoc questionnaire. Direct and indirect costs were estimated from the social perspective.

RESULTS

The GE showed a significant improvement related with strength (maximum respiratory pressures) and endurance (maximum voluntary ventilation) of RM. Moreover, 92% of the EG reported a high satisfaction. The total social costs, direct and indirect, amounted to Euro 21,678.

CONCLUSIONS

This evaluation reveals that RM function improvement is significant, that intervention is well tolerated and appreciated by patients, and the intervention costs are moderate.