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Reprogrammed glucose metabolism as a result of increased glycolysis and glucose uptake is a hallmark of cancer. Here we show that cancer cells can suppress glucose uptake by non-tumour cells in the pre-metastatic niche, by secreting vesicles that carry high levels of the miR-122 microRNA. High miR-122 levels in the circulation have been associated with metastasis in breast cancer patients and we show that cancer-cell-secreted miR-122 facilitates metastasis by increasing nutrient availability in the pre-metastatic niche. Mechanistically cancer-cell-derived miR-122 suppresses glucose uptake by niche cells in vitro and in vivo by downregulating the glycolytic enzyme pyruvate kinase (PKM). In vivo inhibition of miR-122 restores glucose uptake in distant organs, including brain and lungs, and decreases the incidence of metastasis. These results demonstrate that by modifying glucose utilization by recipient pre-metastatic niche cells, cancer-derived extracellular miR-122 is able to reprogram systemic energy metabolism to facilitate disease progression.

Background aimsAlthough recombinant adeno-associated virus serotype 2 (AAV2) vectors have gained attention because of their safety and efficacy in numerous phase I/II clinical trials, their transduction efficiency in hematopoietic stem cells (HSCs) has been reported to be low. Only a few additional AAV serotype vectors have been evaluated, and comparative analyses of their transduction efficiency in HSCs from different species have not been performed.MethodsWe evaluated the transduction efficiency of all available AAV serotype vectors (AAV1 through AAV10) in primary mouse, cynomolgus monkey and human HSCs. The transduction efficiency of the optimized AAV vectors was also evaluated in human HSCs in a murine xenograft model in vivo.ResultsWe observed that although there are only six amino acid differences between AAV1 and AAV6, AAV1, but not AAV6, transduced mouse HSCs well, whereas AAV6, but not AAV1, transduced human HSCs well. None of the 10 serotypes transduced cynomolgus monkey HSCs in vitro. We also evaluated the transduction efficiency of AAV6 vectors containing mutations in surface-exposed tyrosine residues. We observed that tyrosine (Y) to phenylalanine (F) point mutations in residues 445, 705 and 731 led to a significant increase in transgene expression in human HSCs in vitro and in a mouse xenograft model in vivo.ConclusionsThese studies suggest that the tyrosine-mutant AAV6 serotype vectors are the most promising vectors for transducing human HSCs and that it is possible to increase further the transduction efficiency of these vectors for their potential use in HSC-based gene therapy in humans.

Background aims. Although recombinant adeno-associated virus serotype 2 (AAV2) vectors have gained attention because of their safety and efficacy in numerous phase I/II clinical trials, their transduction efficiency in hematopoietic stem cells (HSCs) has been reported to be low. Only a few additional AAV serotype vectors have been evaluated, and comparative analyses of their transduction efficiency in HSCs from different species have not been performed. Methods. We evaluated the transduction efficiency of all available AAV serotype vectors (AAV1 through AAV10) in primary mouse, cynomolgus monkey and human HSCs. The transduction efficiency of the optimized AAV vectors was also evaluated in human HSCs in a murine xenograft model in vivo. Results. We observed that although there are only six amino acid differences between AAV1 and AAV6, AAV1, but not AAV6, transduced mouse HSCs well, whereas AAV6, but not AAV1, transduced human HSCs well. None of the 10 serotypes transduced cynomolgus monkey HSCs in vitro. We also evaluated the transduction efficiency of AAV6 vectors containing mutations in surface-exposed tyrosine residues. We observed that tyrosine (Y) to phenylalanine (F) point mutations in residues 445, 705 and 731 led to a significant increase in transgene expression in human HSCs in vitro and in a mouse xenograft model in vivo. Conclusions. These studies suggest that the tyrosine-mutant AAV6 serotype vectors are the most promising vectors for transducing human HSCs and that it is possible to increase further the transduction efficiency of these vectors for their potential use in HSC-based gene therapy in humans. [ABSTRACT FROM AUTHOR]

Angiotensin II (Ang II)-mediated vascular smooth muscle cell dysfunction plays a critical role in cardiovascular diseases. However, the role of microRNAs (miRNAs) in this process is unclear. We used small RNA deep sequencing to profile Ang II-regulated miRNAs in rat vascular smooth muscle cells (VSMC) and evaluated their role in VSMC dysfunction. Sequencing results revealed several Ang II-responsive miRNAs, and bioinformatics analysis showed that their predicted targets can modulate biological processes relevant to cardiovascular diseases. Further studies with the most highly induced miR-132 and miR-212 cluster (miR-132/212) showed time- and dose-dependent upregulation of miR-132/212 by Ang II through the Ang II Type 1 receptor. We identified phosphatase and tensin homolog (PTEN) as a novel target of miR-132 and demonstrated that miR-132 induces monocyte chemoattractant protein-1 at least in part via PTEN repression in rat VSMC. Moreover, miR-132 overexpression enhanced cyclic AMP-response element- binding protein (CREB) phosphorylation via RASA1 (p120 Ras GTPase-activating protein 1) down-regulation, whereas miR-132 inhibition attenuated Ang II-induced CREB activation. Furthermore, miR-132 up-regulation by Ang II required CREB activation, demonstrating a positive feedback loop. Notably, aortas from Ang II-infused mice displayed similar up-regulation of miR-132/212 and monocyte chemoattractant protein-1, supporting in vivo relevance. In addition, microarray analysis and reverse transcriptasequantitative PCR validation revealed additional novel miR- 132 targets among Ang II-down-regulated genes implicated in cell cycle, motility, and cardiovascular functions. These results suggest that miR132/212 can serve as a novel cellular node to fine-tune and amplify Ang II actions in VSMC. [ABSTRACT FROM AUTHOR]