RESUMO
Despite the implementation of personalized medicine, patients with metastatic CRC (mCRC) still have a dismal overall survival due to the frequent occurrence of acquired resistance mechanisms thereby leading to clinical relapse. Understanding molecular mechanisms that support acquired resistance to anti-EGFR targeted therapy in mCRC is therefore clinically relevant and key to improving patient outcomes. Here, we observe distinct metabolic changes between cetuximab-resistant CRC cell populations, with in particular an increased glycolytic activity in KRAS-mutant cetuximab-resistant CRC cells (LIM1215 and OXCO2) but not in KRAS-amplified resistant DiFi cells. We show that cetuximab-resistant LIM1215 and OXCO2 cells have the capacity to recycle glycolysis-derived lactate to sustain their growth capacity. This is associated with an upregulation of the lactate importer MCT1 at both transcript and protein levels. Pharmacological inhibition of MCT1, with AR-C155858, reduces the uptake and oxidation of lactate and impairs growth capacity in cetuximab-resistant LIM1215 cells both in vitro and in vivo. This study identifies MCT1-dependent lactate utilization as a clinically actionable, metabolic vulnerability to overcome KRAS-mutant-mediated acquired resistance to anti-EGFR therapy in CRC.
Assuntos
Cetuximab , Neoplasias Colorretais , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB , Ácido Láctico , Transportadores de Ácidos Monocarboxílicos , Simportadores , Humanos , Transportadores de Ácidos Monocarboxílicos/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/antagonistas & inibidores , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/genética , Simportadores/metabolismo , Simportadores/genética , Ácido Láctico/metabolismo , Receptores ErbB/metabolismo , Receptores ErbB/antagonistas & inibidores , Cetuximab/farmacologia , Linhagem Celular Tumoral , Animais , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Glicólise/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Proliferação de Células/efeitos dos fármacosRESUMO
Colorectal cancers (CRCs) are highly heterogeneous and show a hierarchical organization, with cancer stem cells (CSCs) responsible for tumor development, maintenance, and drug resistance. Our previous studies showed the importance of thyroid hormone-dependent signaling on intestinal tumor development and progression through action on stem cells. These results have a translational value, given that the thyroid hormone nuclear receptor TRα1 is upregulated in human CRCs, including in the molecular subtypes associated with CSC features. We used an established spheroid model generated from the human colon adenocarcinoma cell line Caco2 to study the effects of T3 and TRα1 on spheroid formation, growth, and response to conventional chemotherapies. Our results show that T3 treatment and/or increased TRα1 expression in spheroids impaired the response to FOLFIRI and conferred a survival advantage. This was achieved by stimulating drug detoxification pathways and increasing ALDH1A1-expressing cells, including CSCs, within spheroids. These results suggest that clinical evaluation of the thyroid axis and assessing TRα1 levels in CRCs could help to select optimal therapeutic regimens for patients with CRC. Proposed mechanism of action of T3/TRα1 in colon cancer spheroids. In the control condition, TRα1 participates in maintaining homeostatic cell conditions. The presence of T3 in the culture medium activates TRα1 action on target genes, including the drug efflux pumps ABCG2 and ABCB1. In the case of chemotherapy FOLFIRI, the increased expression of ABC transcripts and proteins induced by T3 treatment is responsible for the augmented efflux of 5-FU and Irinotecan from the cancer cells. Taken together, these mechanisms contribute to the decreased efficacy of the chemotherapy and allow cells to escape the treatment. Created with BioRender.com .
Assuntos
Camptotecina/análogos & derivados , Neoplasias do Colo , Fluoruracila , Células-Tronco Neoplásicas , Esferoides Celulares , Receptores alfa dos Hormônios Tireóideos , Tri-Iodotironina , Humanos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Receptores alfa dos Hormônios Tireóideos/metabolismo , Receptores alfa dos Hormônios Tireóideos/genética , Células CACO-2 , Neoplasias do Colo/metabolismo , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Neoplasias do Colo/genética , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Tri-Iodotironina/farmacologia , Leucovorina/farmacologia , Leucovorina/uso terapêutico , Camptotecina/farmacologia , Camptotecina/uso terapêutico , Fenótipo , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Família Aldeído Desidrogenase 1/metabolismo , Família Aldeído Desidrogenase 1/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Retinal Desidrogenase/metabolismo , Retinal Desidrogenase/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/genéticaRESUMO
Cancer immunotherapy has become an indispensable mode of treatment for a multitude of solid tumor cancers. Colorectal cancer (CRC) has been one of the many cancer types to benefit from immunotherapy, especially in advanced disease where standard treatment fails to prevent recurrence or results in poor survival. The efficacy of immunotherapy in CRC has not been without challenge, as early clinical trials observed dismal responses in unselected CRC patients treated with checkpoint inhibitors. Many studies and clinical trials have since refined immunotherapies available for CRC, solidifying immunotherapy as a powerful asset for CRC treatment. This review article examines CRC immunotherapies, from their foundation, through emerging avenues for improvement, to future directions.
RESUMO
The THRA gene, encoding the thyroid hormone nuclear receptor TRα1, is expressed in an increasing gradient at the bottom of intestinal crypts, overlapping with high Wnt and Notch activities. Importantly, THRA is upregulated in colorectal cancers, particularly in the high-Wnt molecular subtype. The basis of this specific and/or altered expression pattern has remained unknown. To define the mechanisms controlling THRA transcription and TRα1 expression, we used multiple in vitro and ex vivo approaches. Promoter analysis demonstrated that transcription factors important for crypt homeostasis and altered in colorectal cancers, such as transcription factor 7-like 2 (TCF7L2; Wnt pathway), recombining binding protein suppressor of hairless (RBPJ; Notch pathway), and homeobox protein CDX2 (epithelial cell identity), modulate THRA activity. Specifically, although TCF7L2 and CDX2 stimulated THRA, RBPJ induced its repression. In-depth analysis of the Wnt-dependent increase showed direct regulation of the THRA promoter in cells and of TRα1 expression in murine enteroids. Given our previous results on the control of the Wnt pathway by TRα1, our new results unveil a complex regulatory loop and synergy between these endocrine and epithelial-cell-intrinsic signals. Our work describes, for the first time, the regulation of the THRA gene in specific cell and tumor contexts.
Assuntos
Neoplasias Colorretais , Genes erbA , Humanos , Camundongos , Animais , Receptores dos Hormônios Tireóideos/genética , Receptores alfa dos Hormônios Tireóideos/genética , Receptores alfa dos Hormônios Tireóideos/metabolismo , Hormônios Tireóideos/metabolismo , Neoplasias Colorretais/genéticaRESUMO
Several studies emphasized the function of the thyroid hormones in stem cell biology. These hormones act through the nuclear hormone receptor TRs, which are T3-modulated transcription factors. Pioneer work on T3-dependent amphibian metamorphosis showed that the crosstalk between the epithelium and the underlying mesenchyme is absolutely required for intestinal maturation and stem cell emergence. With the recent advances of powerful animal models and 3D-organoid cultures, similar findings have now begun to be described in mammals, where the action of T3 and TRα1 control physiological and cancer-related stem cell biology. In this review, we have summarized recent findings on the multiple functions of T3 and TRα1 in intestinal epithelium stem cells, cancer stem cells and their niche. In particular, we have highlighted the regulation of metabolic functions directly linked to normal and/or cancer stem cell biology. These findings help explain other possible mechanisms by which TRα1 controls stem cell biology, beyond the more classical Wnt and Notch signaling pathways.
Assuntos
Intestinos , Hormônios Tireóideos , Animais , Mucosa Intestinal/metabolismo , Mamíferos/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Transdução de Sinais , Células-Tronco , Hormônios Tireóideos/metabolismoRESUMO
This publication represents the first to report global information on characteristics and requirements of doctoral programs in the pharmaceutical sciences in schools/colleges of Pharmacy. Survey responses (140 responses) were received from doctoral programs in 23 countries, with the greatest number of responses obtained from Japan, followed by India and the United States. Program characteristics and requirements, and student and faculty information, including graduate placement, in programs in Asia, North America, Europe, Africa and Australia were compared. Survey responses indicated differences in entrance requirements for doctoral programs with minimum requirements being a bachelor's degree, pharmacy degree or master's degree, including a M.Phil. degree. Programs differed widely in size in all geographical areas, but there was a similar emphasis on core educational learning outcomes (core competencies) and Ph.D. graduation requirements including qualifying examinations, thesis defense with internal and external reviewers and requirements for peer-reviewed publications. Additionally, three-quarters of programs indicated that there was external review of their programs every 2-4 or 5-7 years. Female students and female faculty mentors represented about 50% of students/faculty in programs in most geographical areas. Placement of students after graduation indicated that the highest percentage went into the pharmaceutical industry in Asia (predominantly India) and North America, with a lower percentage in Europe, Africa and Australia.
Assuntos
Educação em Farmácia , Feminino , Humanos , África , Europa (Continente) , Inquéritos e Questionários , Estados Unidos , América do Norte , ÁsiaRESUMO
Information on master's programs in the pharmaceutical sciences is lacking; this manuscript addresses this gap in the literature, by reporting on the results of an international survey performed in 2021 of master's programs in the pharmaceutical sciences offered at Schools/Colleges of Pharmacy. Ninety-six responses were received from universities from 23 countries, with the greatest number of responses obtained from India, followed by the United States and Japan. Master's programs in the pharmaceutical sciences are generally full time and 2 years in duration. Only 3% of programs were reported to be examination-based, while the remaining 97% had a research component with 70% of programs having a thesis defense with external and/or internal examiners. Master's programs tended to be larger in Asia and Europe than in North America; as well, programs in North America tended to have more international students. Didactic coursework was included in 96% of master's programs in North America, but only in 38% of Asian and 58% of European programs. The predominant placement of graduates from master's programs in Asia was in the pharmaceutical industry (70%); this contrasted with programs in Europe, Africa and North America where 28-36% enter careers in the pharmaceutical industry and higher percentages enter Ph.D. programs. The major challenge identified by programs was funding of faculty and of graduate students, although decreasing career opportunities was identified as a challenge in Asia and Africa.
Assuntos
Farmácia , Humanos , Estados Unidos , Inquéritos e Questionários , Preparações Farmacêuticas , Europa (Continente) , ÁfricaRESUMO
The thyroid hormone T3 and its nuclear receptor TRα1 control gut development and homeostasis through the modulation of intestinal crypt cell proliferation. Despite increasing data, in-depth analysis on their specific action on intestinal stem cells is lacking. By using ex vivo 3D organoid cultures and molecular approaches, we observed early responses to T3 involving the T3-metabolizing enzyme Dio1 and the transporter Mct10, accompanied by a complex response of stem cell- and progenitor-enriched genes. Interestingly, specific TRα1 loss-of-function (inducible or constitutive) was responsible for low ex vivo organoid development and impaired stem cell activity. T3 treatment of animals in vivo not only confirmed the positive action of this hormone on crypt cell proliferation but also demonstrated its key action in modulating the number of stem cells, the expression of their specific markers and the commitment of progenitors into lineage-specific differentiation. In conclusion, T3 treatment or TRα1 modulation has a rapid and strong effect on intestinal stem cells, broadening our perspectives in the study of T3/TRα1-dependent signaling in these cells.
Assuntos
Proliferação de Células , Intestinos , Transdução de Sinais , Células-Tronco/metabolismo , Receptores alfa dos Hormônios Tireóideos/metabolismo , Tri-Iodotironina/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Animais , Feminino , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Células-Tronco/citologia , Receptores alfa dos Hormônios Tireóideos/genética , Tri-Iodotironina/genéticaRESUMO
Colorectal cancers are characterized by heterogeneity and a hierarchical organization comprising a population of cancer stem cells (CSCs) responsible for tumor development, maintenance, and resistance to drugs. A better understanding of CSC properties for their specific targeting is, therefore, a pre-requisite for effective therapy. However, there is a paucity of suitable preclinical models for in-depth investigations. Although in vitro two-dimensional (2D) cancer cell lines provide valuable insights into tumor biology, they do not replicate the phenotypic and genetic tumor heterogeneity. In contrast, three-dimensional (3D) models address and reproduce near-physiological cancer complexity and cell heterogeneity. The aim of this work was to design a robust and reproducible 3D culture system to study CSC biology. The present methodology describes the development and optimization of conditions to generate 3D spheroids, which are homogenous in size, from Caco2 colon adenocarcinoma cells, a model that can be used for long-term culture. Importantly, within the spheroids, the cells which were organized around lumen-like structures, were characterized by differential cell proliferation patterns and by the presence of CSCs expressing a panel of markers. These results provide the first proof-of-concept for the appropriateness of this 3D approach to study cell heterogeneity and CSC biology, including the response to chemotherapy.