In conclusion, our results demonstrate that the low-passage UT-SCC cell lines evaluated in this study differ in their glycolytic and hypoxic phenotypes. Importantly, these in vitro phenotypic differences can be imaged in vivo and may thus be clinically evaluable using PET. Overall, our results suggest that [18F]EF5 accumulation

in HNSCC not only reflects hypoxia but also is related to an adverse phenotype. [18F]FDG uptake, in turn, may be sensitive to acute changes in oxygenation as suggested by rapid response of expression of HIF-1α to hypoxia in vitro. The hypoxia tracer [18F]EF5 might be useful for the detection of hypoxic and more aggressive mTOR inhibitor HNSCC tumors, and thus, it could assist in planning of hypoxia-directed therapies. The biologic genotype behind the phenotypes reported in this study will need to be evaluated in greater detail. “
“Osteosarcoma is an aggressive AZD2281 malignancy of bone, mainly affecting adolescents and young adults. Interactions between osteosarcoma and bone microenvironment (BME) promote tumor growth and osteoclastic bone destruction. The main goal of this study is to understand the role of extracellular membrane vesicles (EMVs) as potential modulators of osteosarcoma BME and to identify

the key biochemical components of EMVs mediating cellular dynamics and dysregulated pathologic remodeling of the matrix and bone. EMVs are membrane-invested structures that are derived from a number of cells including osteosarcoma

cells [1] and [2]. In recent years, EMVs have received much attention for their role in various diseases and as biomarkers of therapy and disease burden [3]. Recent studies report that tumor cell–derived EMVs support cancer cell growth, survival, metastasis, and angiogenesis, evade host immune surveillance, modulate tumor microenvironment (TMN), and initiate the formation of premetastatic sites [4], [5], [6], [7], [8], [9], [10], [11] and [12]. Tumor-derived EMVs, in general, originate through the fusion Fossariinae of multivesicular bodies (MVBs) with the plasma membrane (exosomes) or by budding (shed vesicles or microvesicles), followed by exocytotic release [13], [14], [15] and [16]. Detection of EMVs and osteoblastic and osteoclastic lesions in the bioluminescent osteosarcoma orthotopic mouse (BOOM) model provides a strong rationale to investigate the role of EMVs in modulating osteosarcoma BME [2]. Biochemical analyses of EMV cargo will be informative as it will identify the key EMV mediators underlying osteosarcoma pathobiology. Biomechanical stress in the bone TMN leads to increased intracellular calcium levels that, in turn, may promote EMV biogenesis, increase the expression of extracellular remodeling enzymes such as matrix metalloproteinases (MMPs), and stimulate exocytotic delivery of bioactive cargo. These biochemical events may result through the activation of G protein–coupled receptors (GPCRs) or calcium-dependent signaling pathways. A study by Ancha et al.