Assuntos
Síndrome Metabólica , Racismo , Adolescente , Humanos , Adulto Jovem , Adulto , Inflamação , SonoRESUMO
OBJECTIVE: Cancer-associated fibroblasts (CAFs) play an important role in the progression of pancreatic ductal adenocarcinoma (PDAC) by promoting tumor cell migration and drug resistance. We determined the impact of CAFs on PDAC cancer stem cells (CSCs). METHODS: Fibroblast cell lines from patients' tumors were cocultured with PDAC cells and examined for clonogenic growth and self-renewal using colony-forming assays and migration in vitro. Changes in the frequency of CSCs was determined by flow cytometry. The effect of integrin-focal adhesion kinase (FAK) signaling on CAF-mediated clonogenic growth was evaluated using short hairpin RNAs against ß1 integrin and FAK as well as a small-molecule FAK inhibitor. RESULTS: Cancer-associated fibroblasts enhanced PDAC clonogenic growth, self-renewal, and migration that was associated with an increase in the frequency of CSCs. These fibroblast cells were activated by PDAC cells and increased collagen synthesis resulting in FAK activation in PDAC cells. Knockdown of ß1-integrin and FAK or the inhibition of FAK kinase activity in PDAC cells abrogated the impact of CAFs on clonogenic growth. CONCLUSION: Therefore, CAFs enhance PDAC clonogenic growth, self-renewal, and the frequency of CSCs through type I collagen production that enhances integrin-FAK signaling in PDAC cells.
Assuntos
Fibroblastos Associados a Câncer/patologia , Comunicação Celular , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/patologia , Fibroblastos Associados a Câncer/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Células Cultivadas , Técnicas de Cocultura , Quinase 1 de Adesão Focal/genética , Quinase 1 de Adesão Focal/metabolismo , Humanos , Integrina beta1/genética , Integrina beta1/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/metabolismo , Interferência de RNA , Transdução de Sinais/genéticaRESUMO
Self-renewal maintains the long-term clonogenic growth that is required for cancer relapse and progression, but the cellular processes regulating this property are not fully understood. In many diseases, self-renewal is enhanced in cancer stem cells (CSC), and in pancreatic ductal adenocarcinoma (PDAC), CSCs are characterized by the surface expression of CD44. In addition to cell adhesion, CD44 impacts cell shape and morphology by modulating the actin cytoskeleton via Ezrin, a member of the Ezrin/Radixin/Moesin (ERM) family of linker proteins. We examined the expression of Ezrin in PDAC cells and found higher levels of both total and activated Ezrin in CSCs compared with bulk tumor cells. We also found that the knockdown of Ezrin in PDAC cells decreased clonogenic growth, self-renewal, cell migration, and CSC frequency in vitro as well as tumor initiation in vivo. These effects were associated with cytoskeletal changes that are similar to those occurring during the differentiation of normal stem cells, and the inhibition of actin remodeling reversed the impact of Ezrin loss. Finally, targeting Ezrin using a small-molecule inhibitor limited the self-renewal of clinically derived low-passage PDAC xenografts. Our findings demonstrate that Ezrin modulates CSCs properties and may represent a novel target for the treatment of PDAC. IMPLICATIONS: Our findings demonstrate that Ezrin modulates CSCs' properties and may represent a novel target for the treatment of PDAC.
Assuntos
Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Proteínas do Citoesqueleto/biossíntese , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Actinas/metabolismo , Adamantano/análogos & derivados , Adamantano/farmacologia , Animais , Linhagem Celular Tumoral , Proteínas do Citoesqueleto/antagonistas & inibidores , Proteínas do Citoesqueleto/metabolismo , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Quinolinas/farmacologiaRESUMO
OBJECTIVES: IQ motif containing GTPase-activating protein 1 (IQGAP1) acts as a scaffold for aberrant mitogen-activated protein kinase (MAPK) signaling driven by KRAS mutations in pancreatic ductal adenocarcinoma (PDAC). We determined the role of IQGAP1 in clonogenic growth and metastasis in PDAC. METHODS: We inhibited IQGAP1 expression using shRNA and assessed clonogenic growth, cell migration, and MAPK signaling in vitro and tumor initiation and metastasis in vivo. The efficacy of a peptide mimicking the IQGAP1 WW domain that binds and inhibits ERK1/2 was determined in vitro and in vivo. RESULTS: IQGAP1 loss inhibited clonogenic growth and migration of KRAS-dependent PDAC cells by disrupting MAPK signaling. In mice, IQGAP1 knockdown decreased tumor-initiating cell frequency and metastasis. WW peptide treatment inhibited clonogenic growth and in vivo tumor growth. CONCLUSIONS: Pancreatic ductal adenocarcinoma clonogenic growth, metastasis, and tumor initiation are dependent on MAPK signaling via IQGAP1. Treatment with a WW peptide disrupts IQGAP1 function and represents a novel targeting strategy for PDAC.
