Papel del tejido adiposo en las propiedades de las células madre tumorales del cáncer de páncreas

El adenocarcinoma ductal pancreático (ADP) es uno de los tumores más mortales con peor pronóstico, cuya incidencia se prevé que aumente en la próxima década. La obesidad constituye un factor de riesgo importante que puede influir promoviendo la progresión tumoral. Por otro lado, su agresividad intrínseca, potencial metastásico y quimioresistencia, se debe, en gran medida, a la subpoblación de células madre tumorales (CSCs) que contiene. Las CSCs pancreáticas son altamente dependientes del metabolismo lipídico, lo que favorece el fenotipo de CSC. En particular, los triacilglicéridos (TAGs) almacenados en gotas lipídicas constituyen una fuente principal energética para las células cancerosas. Estudios previos han asociado la captación de lípidos del microambiente tumoral con la progresión tumoral del ADP. Por ello, el objetivo de este trabajo es estudiar la comunicación entre los adipocitos y las CSCs en cáncer de páncreas.En el presente estudio se ha determinado por análisis bioinformático una sobre-expresión de genes del metabolismo lipídico en el tejido de ADP. La incubación de cultivos primarios de ADP con medio condicionado de adipocitos redujo el contenido de CD133+ e incrementó en esta subpoblación el contenido lipídico. Como consecuencia, se optó por un cocultivo indirecto entre esferas de ADP y adipocitos. Por un lado, el contenido de TAGs en el sobrenadante de cocultivos incrementó, mientras que en los adipocitos en cocultivo hubo una menor acumulación de TAGs. Además, en las esferas de ADP hubo un ligero incremento en el contenido lipídico de las CD133+. Por otro lado, no hubo diferencias en el contenido de CD133+ de las esferas provenientes de cocultivo, confirmado por la expresión de los genes de pluripotencia. Por último, los genes de EMT, SLUG y ZEB1 se sobre-expresaron. Además, se determinó que los lípidos derivados de los adipocitos podrían ser captados por el transportador CD36, sobre-expresado en esferas de ADP.En conclusión, los adipocitos desempeñan un papel importante sobre la funcionalidad de las CSCs pancreáticas, así como induciendo cambios metabólicos en las mismas. De hecho, los adipocitos actúan como donadores de lípidos en las células de ADP, pero el destino de los mismos no está claro ya que existen indicios de un comportamiento diferencial entre líneas celulares. Como resultado, esta puesta a punto ha demostrado que existe una comunicación entre los adipocitos y las CSCs de ADP, lo que incita a profundizar más en el papel del metabolismo lipídico y concretamente del tejido adiposo en el ADP.<br /

Metformin overcomes metabolic reprogramming-induced resistance of skin squamous cell carcinoma to photodynamic therapy

Cancer metabolic reprogramming promotes resistance to therapies. In this study, we addressed the role of the Warburg effect in the resistance to photodynamic therapy (PDT) in skin squamous cell carcinoma (sSCC). Furthermore, we assessed the effect of metformin treatment, an antidiabetic type II drug that modulates metabolism, as adjuvant to PDT. Methods: For that, we have used two human SCC cell lines: SCC13 and A431, called parental (P) and from these cell lines we have generated the corresponding PDT resistant cells (10GT). Results: Here, we show that 10GT cells induced metabolic reprogramming to an enhanced aerobic glycolysis and reduced activity of oxidative phosphorylation, which could influence the response to PDT. This result was also confirmed in P and 10GT SCC13 tumors developed in mice. The treatment with metformin caused a reduction in aerobic glycolysis and an increase in oxidative phosphorylation in 10GT sSCC cells. Finally, the combination of metformin with PDT improved the cytotoxic effects on P and 10GT cells. The combined treatment induced an increase in the protoporphyrin IX production, in the reactive oxygen species generation and in the AMPK expression and produced the inhibition of AKT/mTOR pathway. The greater efficacy of combined treatments was also seen in vivo, in xenografts of P and 10GT SCC13 cells. Conclusions: Altogether, our results reveal that PDT resistance implies, at least partially, a metabolic reprogramming towards aerobic glycolysis that is prevented by metformin treatment. Therefore, metformin may constitute an excellent adjuvant for PDT in sSCCThis research was supported by Spanish grants from Instituto de Salud Carlos III MINECO and Feder Funds (FIS PI15/00974; PI18/00858 and PI18/00708) and Ministerio de Ciencia, Innovación y Universidades (PID2019-108674RB-100

Characterisation of resistance mechanisms developed by basal cell carcinoma cells in response to repeated cycles of photodynamic therapy

photodynamic therapy (pDt) with methyl-aminolevulinate acid (MAL-pDt) is being used for the treatment of Basal cell carcinoma (BCC), but recurrences have been reported. In this work, we have evaluated resistance mechanisms to MAL-pDt developed by three BCC cell lines (AsZ, BsZ and CsZ), derived from mice on a ptch+/− background and with or without p53 expression, subjected to 10 cycles of PDT (10thG). the resistant populations showed mesenchymal-like structure and diminished proliferative capacity and size compared to the parental (p) cells. the resistance was dependent on the production of the endogenous photosensitiser protoporphyrin IX in the CsZ cell line and on its cellular localisation in AsZ and BsZ cells. Moreover, resistant cells expressing the p53 gene presented lower proliferation rate and increased expression levels of N-cadherin and Gsk3β (a component of the Wnt/β-catenin pathway) than P cells. In contrast, 10thG cells lacking the p53 gene showed lower levels of expression of Gsk3β in the cytoplasm and of e-cadherin and β-catenin in the membrane. In addition, resistant cells presented higher tumorigenic ability in immunosuppressed mice. Altogether, these results shed light on resistance mechanisms of BCC to pDt and may help to improve the use of this therapeutic approac

Tumor microenvironment in non-melanoma skin cancer resistance to photodynamic therapy

Non-melanoma skin cancer has recently seen an increase in prevalence, and it is estimated that this grow will continue in the coming years. In this sense, the importance of therapy effectiveness has increased, especially photodynamic therapy. Photodynamic therapy has attracted much attention as a minimally invasive, selective and repeatable approach for skin cancer treatment and prevention. Although its high efficiency, this strategy has also faced problems related to tumor resistance, where the tumor microenvironment has gained a well-deserved role in recent years. Tumor microenvironment denotes a wide variety of elements, such as cancer-associated fibroblasts, immune cells, endothelial cells or the extracellular matrix, where their interaction and the secretion of a wide diversity of cytokines. Therefore, the need of designing new strategies targeting elements of the tumor microenvironment to overcome the observed resistance has become evident. To this end, in this review we focus on the role of cancer-associated fibroblasts and tumor-associated macrophages in the resistance to photodynamic therapy. We are also exploring new approaches consisting in the combination of new and old drugs targeting these cells with photodynamic therapy to enhance treatment outcomes of non-melanoma skin cance

Potent virucidal activity in vitro of photodynamic therapy with Hpericum extract as photosensitizer and white light against human coronavirus HCoV-229E

The emergent human coronavirus SARS-CoV-2 and its high infectivity rate has highlighted the strong need for new virucidal treatments. In this sense, the use of photodynamic therapy (PDT) with white light, to take advantage of the sunlight, is a potent strategy for decreasing the virulence and pathogenicity of the virus. Here, we report the virucidal effect of PDT based on Hypericum extract (HE) in combination with white light, which exhibits an inhibitory activity of the human coronavirus HCoV-229E on hepatocarcinoma Huh-7 cells. Moreover, despite continuous exposure to white light, HE has long durability, being able to maintain the prevention of viral infection. Given its potent in vitro virucidal capacity, we propose HE in combination with white light as a promising candidate to fight against SARS-CoV-2 as a virucidal compoundThis research was funded by Fundación Universidad Autónoma de Madrid, grant number PI21/00315 and by Instituto de Salud Carlos III, grant number PI21/00953. Institutional Review Board Statement: Not applicabl

Metabolic reprogramming involved in resistance to photodynamic therapy in non-melanoma skin cancer. Metformin as adjuvant

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 24-03-2021Esta tesis tiene embargado el acceso al texto completo hasta el 24-09-2022La terapia fotodinámica (TFD) con el éster metilado del ácido aminolevulínico (MAL) es utilizada para el tratamiento del cáncer cutáneo no melanoma (CCNM), concretamente del carcinoma basocelular (CBC) y del carcinoma de células escamosas (CCE). Sin embargo, la TFD no siempre es eficaz y pueden aparecer células resistentes responsables de las recidivas. Se ha descrito que las células tumorales cambian su metabolismo promoviendo la glucolisis aeróbica para la obtención de energía en vez de obtenerla mediante la fosforilación oxidativa (OXPHOS), como ocurre en las células diferenciadas. Lo cual, podría influir en el proceso de resistencia a drogas antitumorales. En este trabajo hemos valorado la implicación de marcadores metabólicos (β-F1-ATPasa/GAPDH, PKM2, consumo de oxígeno y producción de lactato) en el proceso de resistencia a la TFD en el CCNM tanto in vitro como in vivo. También hemos evaluado el uso de la metformina, un compuesto antidiabético tipo II modulador del metabolismo glucolítico, para sensibilizar a las células resistentes a la TFD. Para ello, hemos utilizado líneas celulares de CBC de ratón (ASZ y CSZ) y de CCE humanas (A431 y SCC13). Estas células, denominadas parentales (P), se sometieron a 10 ciclos de TFD para obtener células resistentes (10G), que se inocularon en ratones inmunosuprimidos. Los tumores generados fueron recultivados obteniéndose una nueva población resistente (10GT). Los resultados indicaron que la adquisición de la resistencia implicó la reprogramación del metabolismo celular (aumento de glucolisis aeróbica y reducción de la OXPHOS). Este resultado también se confirmó en los tumores inducidos en ratones por inoculación de las poblaciones P y resistentes de ASZ y SCC13. La metformina, por ella misma, ocasionó parada del ciclo en la fase G0/G1 y reducción de la glucolisis aeróbica en todas las líneas celulares. Además, tras el tratamiento, las células resistentes de CBC redujeron los niveles de la OXPHOS, mientras que las de CCE lo aumentaron. En cualquier caso, el tratamiento con metformina mejoró el efecto citotóxico de la TFD (tratamiento combinado), tanto de las células P como resistentes. El mecanismo de acción por el que la metformina potenció la acción de la TFD fue dependiente del tipo celular. En ASZ ocasionó sobre-expresión de AMPK e inhibición de elementos de la vía de mTOR; en CSZ indujo hiperpolarización de la membrana mitocondrial; y en las células de CCE (A431 y SCC13) incrementó la producción de protoporfirina IX, de especies reactivas de oxígeno y de AMPK e inhibió la vía de mTOR. El incremento de la eficacia de la TFD en combinación con metformina también se apreció in vivo, en tumores inducidos por células P y resistentes de CBC y CCE. Además, el tratamiento combinado retrasó la aparición de lesiones en ratones expuestos crónicamente a la luz UV y redujo la expresión de marcadores que se activan en respuesta al daño por luz UV, incluyendo P53, PCNA y mTOR. En conclusión, podemos indicar que la resistencia a la TFD con MAL conlleva una reprogramación metabólica hacia un metabolismo glucolítico y el tratamiento con metformina lo revierte. Por ello, proponemos a la metformina como un excelente agente adyuvante que potencia la TFD en el tratamiento del CCNM, tanto de CBC como de CC

Tgfβ1 secreted by cancer-associated fibroblasts as an inductor of resistance to photodynamic therapy in squamous cell carcinoma cells

SIMPLE SUMMARY: Photodynamic therapy (PDT) is used for the treatment of in situ cutaneous squamous cell carcinoma (cSCC), the second most common form of skin cancer, as well as for its precancerous form, actinic keratosis. However, relapses after the treatment can occur. Transforming growth factor β1 (TGFβ1) produced by cancer-associated fibroblasts (CAFs) in the tumor microenvironment has been pointed as a key player in the development of cSCC resistance to other therapies, such as chemotherapy. Here, we demonstrate that TGFβ1 produced by CAFs isolated from patients with cSCC can drive resistance to PDT in SCC cells. This finding opens up novel possibilities for strategy optimization in the field of cSCC resistance to PDT and highlights CAF-derived TGFβ1 as a potential target to improve the efficacy of PDT. ABSTRACT: As an important component of tumor microenvironment, cancer-associated fibroblasts (CAFs) have lately gained prominence owing to their crucial role in the resistance to therapies. Photodynamic therapy (PDT) stands out as a successful therapeutic strategy to treat cutaneous squamous cell carcinoma. In this study, we demonstrate that the transforming growth factor β1 (TGFβ1) cytokine secreted by CAFs isolated from patients with SCC can drive resistance to PDT in epithelial SCC cells. To this end, CAFs obtained from patients with in situ cSCC were firstly characterized based on the expression levels of paramount markers as well as the levels of TGFβ1 secreted to the extracellular environment. On a step forward, two established human cSCC cell lines (A431 and SCC13) were pre-treated with conditioned medium obtained from the selected CAF cultures. The CAF-derived conditioned medium effectively induced resistance to PDT in A431 cells through a reduction in the cell proliferation rate. This resistance effect was recapitulated by treating with recombinant TGFβ1 and abolished by using the SB525334 TGFβ1 receptor inhibitor, providing robust evidence of the role of TGFβ1 secreted by CAFs in the development of resistance to PDT in this cell line. Conversely, higher levels of recombinant TGFβ1 were needed to reduce cell proliferation in SCC13 cells, and no induction of resistance to PDT was observed in this cell line in response to CAF-derived conditioned medium. Interestingly, we probed that the comparatively higher intrinsic resistance to PDT of SCC13 cells was mediated by the elevated levels of TGFβ1 secreted by this cell line. Our results point at this feature as a promising biomarker to predict both the suitability of PDT and the chances to optimize the treatment by targeting CAF-derived TGFβ1 in the road to a more personalized treatment of particular cSCC tumors