More than 50% of human tumors display hyperactivation of the serine/threonine kinase AKT. Despite evidence of clinical efficacy, the therapeutic window of the current generation of AKT inhibitors could be improved. Here, we report the development of a second-generation AKT degrader, INY-05-040, which outperformed catalytic AKT inhibition with respect to cellular suppression of AKT-dependent phenotypes in breast cancer cell lines.
View Article and Find Full Text PDFBackground: Branched-chain aminotransferase 1 (BCAT1) has been proposed to drive proliferation and invasion of isocitrate dehydrogenase () wild-type glioblastoma cells. However, the Cancer Genome Atlas (TCGA) dataset shows considerable variation in the expression of this enzyme in glioblastoma. The aim of this study was to determine the role of BCAT1 in driving the proliferation and invasion of glioblastoma cells and xenografts that have widely differing levels of BCAT1 expression and the mechanism responsible.
View Article and Find Full Text PDFMutations in the TP53 gene are common in cancer with the R248Q missense mutation conferring an increased propensity to aggregate. Previous p53 aggregation studies showed that, at micromolar concentrations, protein unfolding to produce aggregation-prone species is the rate-determining step. Here we show that, at physiological concentrations, aggregation kinetics of insect cell-derived full-length wild-type p53 and p53R248Q are determined by a nucleation-growth model, rather than formation of aggregation-prone monomeric species.
View Article and Find Full Text PDFC nuclear spin hyperpolarization can increase the sensitivity of detection in an MRI experiment by more than 10,000-fold. C magnetic resonance spectroscopic imaging (MRSI) of hyperpolarized C label exchange between injected [1-C]pyruvate and the endogenous tumor lactate pool can be used clinically to assess tumor grade and response to treatment. We describe here an experimental protocol for using this technique in patient-derived and established cell line xenograft models of breast cancer in the mouse.
View Article and Find Full Text PDFIntroduction: Trialing novel cancer therapies in the clinic would benefit from imaging agents that can detect early evidence of treatment response. The timing, extent and distribution of cell death in tumors following treatment can give an indication of outcome. We describe here an F-labeled derivative of a phosphatidylserine-binding protein, the C2A domain of Synaptotagmin-I (C2Am), for imaging tumor cell death in vivo using PET.
View Article and Find Full Text PDFTumor-associated macrophages (TAMs) can exist in pro- and anti-inflammatory states. Anti-inflammatory TAMs (also referred to as M2-polarized) generally suppress antitumor immune responses and enhance the metastatic progression of cancer. To explore the mechanisms behind this phenomenon, we isolated macrophages from mice and humans, polarized them ex vivo, and examined their functional interaction with breast cancer cells in culture and in mice.
View Article and Find Full Text PDFPIK3CA, encoding the PI3Kα isoform, is the most frequently mutated oncogene in estrogen receptor (ER)-positive breast cancer. Isoform-selective PI3K inhibitors are used clinically but intrinsic and acquired resistance limits their utility. Improved selection of patients that will benefit from these drugs requires predictive biomarkers.
View Article and Find Full Text PDFMetabolic imaging has been widely used to measure the early responses of tumors to treatment. Here, we assess the abilities of PET measurement of [F]FDG uptake and MRI measurement of hyperpolarized [1-C]pyruvate metabolism to detect early changes in glycolysis following treatment-induced cell death in human colorectal (Colo205) and breast adenocarcinoma (MDA-MB-231) xenografts in mice. A TRAIL agonist that binds to human but not mouse cells induced tumor-selective cell death.
View Article and Find Full Text PDFExisting methods to improve detection of circulating tumor DNA (ctDNA) have focused on genomic alterations but have rarely considered the biological properties of plasma cell-free DNA (cfDNA). We hypothesized that differences in fragment lengths of circulating DNA could be exploited to enhance sensitivity for detecting the presence of ctDNA and for noninvasive genomic analysis of cancer. We surveyed ctDNA fragment sizes in 344 plasma samples from 200 patients with cancer using low-pass whole-genome sequencing (0.
View Article and Find Full Text PDFC MRI of hyperpolarized [1-C]pyruvate metabolism has been used in oncology to detect disease, investigate disease progression, and monitor response to treatment with a view to guiding treatment in individual patients. This technique has translated to the clinic with initial studies in prostate cancer. Here, we use the technique to investigate its potential uses in patients with glioblastoma (GB).
View Article and Find Full Text PDFThe development of new treatments and their deployment in the clinic may be assisted by imaging methods that allow an early assessment of treatment response in individual patients. The C2A domain of Synaptotagmin-I (C2Am), which binds to the phosphatidylserine (PS) exposed by apoptotic and necrotic cells, has been developed as an imaging probe for detecting cell death. Multispectral optoacoustic tomography (MSOT) is a real-time and clinically applicable imaging modality that was used here with a near infrared (NIR) fluorophore-labeled C2Am to image tumor cell death in mice treated with a TNF-related apoptosis-inducing ligand receptor 2 (TRAILR2) agonist and with 5-fluorouracil (5-FU).
View Article and Find Full Text PDFBackground And Objective: Advanced glycation end-products (AGEs) are a marker of metabolic memory. Their levels increases when oxidative stress, inflammation, or chronic hyperglycemia exists. The role of morbid obesity in AGE levels, and the impact of bariatric surgery on them are unknown.
View Article and Find Full Text PDFNon-invasive imaging of gene expression can be used to track implanted cells in vivo but often requires the addition of an exogenous contrast agent that may have limited tissue access. We show that the urea transporter (UT-B) can be used as a gene reporter, where reporter expression is detected using H MRI measurements of UT-B-mediated increases in plasma membrane water exchange. HEK cells transfected with the reporter showed an increased apparent water exchange rate (AXR), which increased in line with UT-B expression.
View Article and Find Full Text PDFTumor resection in papillary thyroid carcinoma (PTC) is often accompanied by lymph node (LN) removal of the central and lateral cervical compartments. One-step nucleic acid amplification (OSNA) is a polymerase chain reaction-based technique that quantifies cytokeratin 19 (CK19) messenger RNA copies. Our aim is to assess the value of OSNA in detection of LN metastases in PTC, in comparison with imprints and microscopic analysis of formalin-fixed, paraffin-embedded (FFPE) tissue.
View Article and Find Full Text PDFMetabolic reprogramming in cancer enhances macromolecule biosynthesis and supports cell survival. Oncogenic drivers affect metabolism by altering distinct metabolic processes and render cancer cells sensitive to perturbations of the metabolic network. This study aimed to identify selective metabolic dependencies in breast cancer by investigating 17 breast cancer cells lines representative of the genetic diversity of the disease.
View Article and Find Full Text PDFThe increased glucose metabolism in cancer cells is required to fulfill their high energetic and biosynthetic demands. Changes in the metabolic activity of cancer cells are caused by the activation of oncogenes or loss of tumor suppressors. They can also be part of the metabolic adaptations to the conditions imposed by the tumor microenvironment, such as the hypoxia response.
View Article and Find Full Text PDFBackground: Regulation of lipid metabolism via activation of sterol regulatory element binding proteins (SREBPs) has emerged as an important function of the Akt/mTORC1 signaling axis. Although the contribution of dysregulated Akt/mTORC1 signaling to cancer has been investigated extensively and altered lipid metabolism is observed in many tumors, the exact role of SREBPs in the control of biosynthetic processes required for Akt-dependent cell growth and their contribution to tumorigenesis remains unclear.
Results: We first investigated the effects of loss of SREBP function in non-transformed cells.