RESUMO
Patient-derived xenograft (PDX) mouse models are useful for deepening our understanding of the biology of malignant lymphoma; however, factors associated with the success of the PDX lymphoma model are largely unknown. We retrospectively analyzed the characteristics of 66 xenotransplantations from 65 patients. In all, 43 (65%) specimens were obtained from patients aged > 60 years, and 42 (64%) specimens were obtained at diagnosis. Specimens were obtained from patients with the following diseases: diffuse large B-cell lymphoma (n = 30), intravascular large B-cell lymphoma (n = 12), follicular lymphoma (n = 8), peripheral T-cell lymphoma (n = 7), mantle cell lymphoma (n = 2), and other (n = 7). The specimens were sourced mainly from bone marrow (n = 31, 47%) and extranodal tumors (n = 13, 20%). Engraftment was successful in 33/66 (50%) xenotransplantations. The median age of patients who provided successful specimens was significantly higher than that for unsuccessful specimens (p = 0.013). Specimens with a high proportion of tumor cells in the graft and those obtained from patients with relapsed/refractory disease showed higher tendencies toward successful engraftment. Taken together, these data suggest that tumor cells with a highly malignant potential might have a high likelihood of engraftment.
Assuntos
Linfoma Folicular , Linfoma Difuso de Grandes Células B , Linfoma de Célula do Manto , Humanos , Animais , Camundongos , Adulto , Estudos Retrospectivos , Linfoma Difuso de Grandes Células B/terapia , Linfoma Difuso de Grandes Células B/patologia , Linfoma Folicular/patologia , Linfoma de Célula do Manto/patologia , Linfócitos/patologiaRESUMO
The tumor microenvironment is deeply involved in the process of tumor growth and development. In this study, we focused on cancer-associated fibroblasts (CAFs) and their derived exosomes on the lymphoma microenvironment to uncover their clinical significance. CAFs were established from primary lymphoma samples, and exosomes secreted from CAFs were obtained by standard procedures. We then investigated the roles of CAFs and their derived exosomes in the survival and drug resistance of lymphoma cells. CAFs supported the survival of lymphoma cells through increased glycolysis, and the extent differed among CAFs. Exosomes were identified as a major component of the extracellular vesicles from CAFs, and they also supported the survival of lymphoma cells. The suppression of RAB27B, which is involved in the secretion of exosomes, using a specific siRNA resulted in reduced exosome secretion and decreased survival of lymphoma cells. Moreover, anti-pyrimidine drug resistance was induced in the presence of exosomes through the suppression of the pyrimidine transporter, equilibrative nucleoside transporter 2 (ENT2), and the suppression of ENT2 was significant in in vivo experiments and clinical samples. RNA sequencing analysis of miRNAs in exosomes identified miR-4717-5p as one of the most abundant miRNAs in the exosome, which suppressed the expression of ENT2 and induced anti-pyrimidine drug resistance in vitro. Our results suggest that exosomes including miR-4717-5p secreted from CAFs play a pivotal role in the lymphoma microenvironment, indicating that they are a promising therapeutic target.
Assuntos
Fibroblastos Associados a Câncer/metabolismo , Desoxicitidina/análogos & derivados , Exossomos/metabolismo , Linfoma/tratamento farmacológico , Animais , Antimetabólitos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citarabina/farmacologia , Desoxicitidina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Transportador Equilibrativo 2 de Nucleosídeo/metabolismo , Humanos , Linfoma/genética , Linfoma/metabolismo , Linfoma/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , MicroRNAs/genética , MicroRNAs/metabolismo , Cultura Primária de Células , Microambiente Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , GencitabinaRESUMO
Cancer-associated fibroblasts (CAF) are a key component in the tumor microenvironment and play functional roles in tumor metastasis and resistance to chemotherapies. We have previously reported that CAF isolated from lymphoma samples increase anaerobic glycolysis and decrease intracellular production of reactive oxygen species, promoting the survival of tumor cells. Herein, we analyzed the mechanisms underlying this support of tumor-cell survival by CAF. As direct contact between lymphoma cells and CAF was not indispensable to survival support, we identified that the humoral factor pyruvate was significantly secreted by CAF. Moreover, survival of lymphoma cells was promoted by the presence of pyruvate, and this promotion was canceled by inhibition of monocarboxylate transporters. Metabolome analysis of lymphoma cells in coculture with CAF demonstrated that intermediates in the citric acid cycle were significantly increased, indicating that tumor cells produced energy by aerobic metabolism. These findings indicate that energy production in lymphoma cells is regulated in coordination not only with anaerobic glycolysis, but also with aerobic metabolism termed the reverse-Warburg effect, involving the secretion of pyruvate from CAF resulting in increased use of the citric acid cycle in lymphoma cells.