RESUMO
Cross-talk among oncogenic signaling and metabolic pathways may create opportunities for new therapeutic strategies in cancer. Here we show that although acute inhibition of EGFR-driven glucose metabolism induces only minimal cell death, it lowers the apoptotic threshold in a subset of patient-derived glioblastoma (GBM) cells. Mechanistic studies revealed that after attenuated glucose consumption, Bcl-xL blocks cytoplasmic p53 from triggering intrinsic apoptosis. Consequently, targeting of EGFR-driven glucose metabolism in combination with pharmacological stabilization of p53 with the brain-penetrant small molecule idasanutlin resulted in synthetic lethality in orthotopic glioblastoma xenograft models. Notably, neither the degree of EGFR-signaling inhibition nor genetic analysis of EGFR was sufficient to predict sensitivity to this therapeutic combination. However, detection of rapid inhibitory effects on [18F]fluorodeoxyglucose uptake, assessed through noninvasive positron emission tomography, was an effective predictive biomarker of response in vivo. Together, these studies identify a crucial link among oncogene signaling, glucose metabolism, and cytoplasmic p53, which may potentially be exploited for combination therapy in GBM and possibly other malignancies.
Assuntos
Apoptose , Neoplasias Encefálicas/metabolismo , Citoplasma/metabolismo , Glioblastoma/metabolismo , Glucose/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Neoplasias Encefálicas/patologia , Receptores ErbB/metabolismo , Feminino , Glioblastoma/patologia , Humanos , Camundongos , Camundongos Endogâmicos NOD , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVES: Recently cell therapy is a promising therapeutic modality for many types of disease including acute kidney injury (AKI). Due to the unique biological properties, mesenchymal stem cells (MSCs) are attractive cells in this regard. This study aims to transplant MSCs equipped with nuclear factor E2-related factor 2 (Nrf2) in rat experimental models of acute kidney and evaluate regeneration potential of injured kidney especially expression of injury and repaired biomarkers. MATERIALS AND METHODS: Nrf2 was overexpressed in bone marrow-derived MSCs by pcDNA.3.1 plasmid. AKI was induced using glycerol in rat models. The regenerative potential of Nrf2-overexpressed MSCs was evaluated in AKI-Induced animal models using biochemical and histological methods after transplantation. Expression of repaired genes, AQP1 and CK-18, as well as injury markers, Kim-1 and Cystatin C, was also assayed in engrafted kidney sections. RESULTS: Our results revealed that transplantation of Nrf2-overexpressed MSCs into AKI-induced rats decreased blood urea nitrogen and creatinine and ameliorated kidney regeneration throughout 14 days. Upregulation of repaired markers and downregulation of injury markers were considerable 14 days after transplantation. CONCLUSIONS: Overexpression of Nrf2 in MSCs suggests a new strategy to increase efficiency of MSC-based cell therapy in AKI.
RESUMO
One of the major obstacles in cancer therapy is the lack of anticancer agent specificity to tumor tissues. The strategy of cell-based therapy is a promising therapeutic option for cancer treatment. The specific tumor-oriented migration of mesenchymal stem cells (MSCs) makes them a useful vehicle to deliver anticancer agents. In this study, we genetically manipulated bone marrow-derived mesenchymal stem cells with their lipocalin 2 (Lcn2) in order to inhibit liver metastasis of colon cancer in nude mice. Lcn2 was successfully overexpressed in transfected MSCs. The PCR results of SRY gene confirmed the presence of MSCs in cancer liver tissue. This study showed that Lcn2-engineered MSCs (MSC-Lcn2) not only inhibited liver metastasis of colon cancer but also downregulated the expression of vascular endothelial growth factor (VEGF) in the liver. Overall, MSCs by innate tropism toward cancer cells can deliver the therapeutic agent, Lcn2, and inhibit cancer metastasis. Hence, it could be a new modality for efficient targeted delivery of anticancer agent to liver metastasis.