Transitions in metabolic pathways coincide with many important changes in cellular functions. Fundamental throughout evolution, metabolic switches are evident in yeast growth dynamics, embryonic development, mammalian cerebral responses, and immune system responses to pathogens. In addition to normal transitions in biological processes, metabolic switches are also hallmark features of malignant transformation. These include the metabolic switch from oxidative metabolism to glycolysis by cancer cells, which yields dramatic increases in glucose metabolism to accommodate a low yield energy production and changes in a number of biochemical pathways that switch to a dependence on glucose metabolism. Such changes have a profound impact on tumor cell proliferation, survival and metastasis via cell-autonomous effects. They also alter the heterotypic tumor microenvironment by the efflux of byproducts of glycolysis, such as protons and lactate, that can produce effects favorable to malignant cells but that can alter functions of, non-malignant cell populations in the surrounding environment There is growing evidence that this metabolic switch in cancer also provides for the use of glucose metabolites for anabolic purposes, such as nucleotide and fatty acid biosynthesis, required to support cell growth. However, the molecular instruction sets responsible for the metabolic switch to glycolysis, as well as the functional consequences for cancer cells and other cells within the microenvironment, in particular tumor infiltrating lymphocytes (TILs), have not been defined. This project employs new in vitro and in vivo (in mouse models) technologies to investigate the molecular commands that rearrange biochemical pathways during malignant transformations, as well as the biochemical and biological outcomes. Our group brings expertise in non-invasive metabolic imaging and integration of such technologies and principles into a microfiuidics chips. Technologies include: 1) the BetaBox for high throughput measurements of rate constants and fiuxes for glucose, nucleotide and lipid metabolism at single and multiple cell levels using a Si chip camera, embedded within a microfluidics-based cell culture array. The camera images positron emission (or any other beta particle emission;e.g., C-14, P-32) from labeled tracers. In vitro imaging using the BetaBox N be followed by in vivo imaging using microPET. This research is facilitated by a microfluidic based radiosynthesizer designed for simplified development and producfion of PET radiolabeled molecular imaging probes. These technologies, although driven by the cancer biology of this project, generally allow for expanding in vitro and in vivo molecular imaging assays. The platforms will be exportable to the other NCI centers and have a commercialization route through Sofie Biosciences. The multidisciplinary team includes expertise in molecular and cellular biology, immunology, chemistry, radiochemistry, biomathematics, physics, and engineering. Our primary focus is to develop and use in vitro molecular assays and devices to develop novel in vivo molecular imaging diagnostic assays of the biology and biochemistry of cancer. Our oncology focus is on early malignant transformations for diagnostics and alignment of molecular imaging diagnostics with the development, selection and assessment of the molecular, nanoparticle and adoptive cell targeted therapies explored in other NSBCC projects. Our goals are: 1) Better define how metabolic switches in cancer cells drive tumor proliferation, survival and progression, and define how those switches interfere with tumor recognition by cells of the adaptive immune system. 2) Develop novel enabling technologies for high throughput in vitro and in vivo preclinical imaging measurements that enable the study of metabolic switching mechanisms employed during the malignant transformation and for discovery of new PET molecular imaging probes. 3) Develop low cost, easyto-use chips for developing and synthesizing diverse arrays of PET molecular imaging probes. These chips can give basic and clinical scientists the means to investigate the biochemistry of cancer in vivo, from mouse models to patients and provide the means to translate that knowledge into diversified in vivo diagnostics. 4) Accelerate the integration of targeted molecular imaging diagnostics with targeted molecular therapeutics to improve the care of cancer patients by aiding in selection of the right drug(s) for the right patient. By comparing gene expression data with metabolic measurements from a large set of human breast cancer cell lines, we have identified a list of candidate metabolic regulator genes that strongly correlate with the glycolytic phenotype in vitro and in vivo as determined by PET studies in patients with the glucose analog, 2-deoxy-2-[ [8] F]fluoro-D-glucose (FDG). By inducing the loss of funtion of two of these candidate metabolic regulator genes tested thus far, we were able to switch cancer cells from their malignant phenotype of glycolysis to normal oxidative metabolism in vitro. These metabolic regulators or molecular commands (and others validated to affect the switch) will be used as tools to study biological outcomes of metabolic switches in cancer, both in malignant transformations and the impact on normal cells in the tumor microenvironment.
Showing the most recent 10 out of 55 publications
