RESUMO
Advances made in pancreatic cancer therapy have been far from sufficient and have allowed only a slight improvement in global survival of patients with pancreatic ductal adenocarcinoma (PDA). Recent progresses in chemotherapy have offered some hope for an otherwise gloomy outlook, however, only a limited number of patients are eligible because of important cytotoxicity. In this context, enhancing our knowledge on PDA initiation and evolution is crucial to highlight certain weaknesses on which to specifically target therapy. We found that loss of transcriptionally active p73 (TAp73), a p53 family member, impacted PDA development. In two relevant and specific engineered pancreatic cancer mouse models, we observed that TAp73 deficiency reduced survival and enhanced epithelial-to-mesenchymal transition (EMT). Through proteomic analysis of conditioned media from TAp73 wild-type (WT) and deficient pancreatic tumor cells, we identified a secreted protein, biglycan (BGN), which is necessary and sufficient to mediate this pro-EMT effect. Interestingly, BGN is modulated by and modulates the transforming growth factor-ß (TGF-ß) pathway, a key regulator of the EMT process. We further examined this link and revealed that TAp73 impacts the TGF-ß pathway by direct regulation of BGN expression and Sma and Mad-related proteins (SMADs) expression/activity. Absence of TAp73 leads to activation of TGF-ß signaling through a SMAD-independent pathway, favoring oncogenic TGF-ß effects and EMT. Altogether, our data highlight the implication of TAp73 in the aggressiveness of pancreatic carcinogenesis through modulation of the TGF-ß signaling. By suggesting TAp73 as a predictive marker for response to TGF-ß inhibitors, our study could improve the classification of PDA patients with a view to offering combined therapy involving TGF-ß inhibitors.
Assuntos
Carcinoma Ductal Pancreático/patologia , Proteínas Nucleares/metabolismo , Neoplasias Pancreáticas/patologia , Transdução de Sinais , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Biglicano/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/mortalidade , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal , Humanos , Masculino , Camundongos , Camundongos Knockout , Camundongos Nus , Camundongos Transgênicos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/mortalidade , Interferência de RNA , Transdução de Sinais/fisiologia , Taxa de Sobrevida , Fator de Crescimento Transformador beta/antagonistas & inibidores , Fator de Crescimento Transformador beta/farmacologia , Células Tumorais CultivadasRESUMO
Pancreatic ductal adenocarcinoma (PDA) is a critical health issue in the field of cancer, with few therapeutic options. Evidence supports an implication of the intratumoral microenvironment (stroma) on PDA progression. However, its contribution to the role of neuroplastic changes within the pathophysiology and clinical course of PDA, through tumor recurrence and neuropathic pain, remains unknown, neglecting a putative, therapeutic window. Here, we report that the intratumoral microenvironment is a mediator of PDA-associated neural remodeling (PANR), and we highlight factors such as 'SLIT2' (an axon guidance molecule), which is expressed by cancer-associated fibroblasts (CAFs), that impact on neuroplastic changes in human PDA. We showed that 'CAF-secreted SLIT2' increases neurite outgrowth from dorsal root ganglia neurons as well as from Schwann cell migration/proliferation by modulating N-cadherin/ß-catenin signaling. Importantly, SLIT2/ROBO signaling inhibition disrupts this stromal/neural connection. Finally, we revealed that SLIT2 expression and CAFs are correlated with neural remodeling within human and mouse PDA. All together, our data demonstrate the implication of CAFs, through the secretion of axon guidance molecule, in PANR. Furthermore, it provides rationale to investigate the disruption of the stromal/neural compartment connection with SLIT2/ROBO inhibitors for the treatment of pancreatic cancer recurrence and pain.
Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Animais , Axônios/efeitos dos fármacos , Axônios/metabolismo , Caderinas/metabolismo , Comunicação Celular/efeitos dos fármacos , Compartimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Meios de Cultura/farmacologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos Nus , Modelos Biológicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neoplasias Pancreáticas/genética , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Células de Schwann/patologia , Transdução de Sinais/efeitos dos fármacos , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Células Estromais/patologia , Transcriptoma/genética , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/genética , beta Catenina/metabolismo , Neoplasias PancreáticasRESUMO
The multiple isoforms of p73, a member of the p53 family, share the ability to modulate p53 activities but also have unique properties, leading to a complex and poorly understood functional network. In vivo, p73 isoforms have been implicated in tumor suppression (TAp73(-/-) mice), DNA damage (ΔNp73(-/-) mice) and development (p73(-/-) mice). In this study, we investigated whether TAp73 contributes to innate immunity and septic shock. In response to a lethal lipopolysaccharide (LPS) challenge, TAp73(-/-) mice showed higher blood levels of proinflammatory cytokines and greater mortality than their wild-type littermates. In vitro, TAp73(-/-) macrophages exhibited elevated production of tumor necrosis factor alpha , interleukin-6 and macrophage inflammatory protein-2 as well as prolonged survival, decreased phagocytosis and increased major histocompatibility complex class II expression. Mice depleted of endogenous macrophages and reconstituted with TAp73(-/-) macrophages showed increased sensitivity to LPS challenge. These results suggest that macrophage polarization is altered in the absence of TAp73 such that maintenance of the M1 effector phenotype is prolonged at the expense of the M2 phenotype, thus impairing resolution of the inflammatory response. Our data indicate that TAp73 has a role in macrophage polarization and innate immunity, enhancing the action field of this important regulatory molecule.