Cancer Preclinical: Cells to Animals

Thursday 15 May 2014

Balaji Krishnamachary¹, Santosh Kumar Bharti¹, Marie-France Pennet¹, Samata M Kakkad¹, Flonne Wildes¹, Keve Zoltani¹, Yelena Mironchik¹, and Zaver M Bhujwalla^1
1Radiology, Johns Hopkins University, Baltimore, MD, United States

Hypoxic tumors frequently exhibit an aggressive phenotype due to dysregulated gene expression and metabolic changes. Cancers typically exhibit elevated phosphocholine mostly due to increased choline kinase expression and activity. Here we have established a relationship between hypoxia inducible factor (HIF) and choline distribution in vivo, and have shown that silencing both HIF-1α and HIF-2α reduces total choline and metastatic burden. We have identified a role for CD44, a breast cancer stem-like cell marker, in lung colonization

Kimberly Brewer¹, Adam J Shuhendler¹, Deju Ye¹, Prachi Pandit¹, Magdalena Bazalova², Edward Graves², Jianghong Rao¹, and Brian K Rutt^1
1Radiology, Molecular Imaging Program, Stanford University, Stanford, California, United States, ²Radiation Oncology, Stanford University, Stanford, California, United States

Our group has previously reported on the development of a novel MRI caspase-3 activatable contrast agent based on intramolecular cyclization. Introduced into the system as small molecules, it cyclizes and self-assembles into Gd-nanoaggregates inside of target cells. We investigated caspase-3 activity (and thus apoptotic cells) in two different but common treatment modalities, chemotherapy and radiation therapy, that induce apoptosis in cancer cells. We found significant MRI signal enhancement for both sets of treated mice, each with distinct intratumoral localization. By studying the differences in caspase activity and localization we can explore the efficiency of these clinically relevant cancer treatments.

Yanan Zhu¹, Rajiv Ramasawmy¹, Sean Peter Johnson², Valerie Taylor¹, Barbara Pedley², Allison Berger³, Nibedita Chattopadhyay³, Daniel Bradley⁴, Mark Lythgoe¹, and Simon Walker-Samuel^1
1UCL Centre for Advanced Biomedical Imaging, University College London, London, Greater London, United Kingdom, ²UCL Cancer Institute, University College London, Greater London, United Kingdom, ³Cancer Pharmacology Takeda Pharmaceutical International Corporation, MA, United States, ⁴The Biomedical Imaging Group, Takeda Pharmaceutical International Corporation, MA, United States

In this study, amide proton transfer (APT) imaging was used to assess the acute response of a colorectal xenograft model to proteosome inhibitor therapy (ixazomib). Tumour apparent diffusion coefficient (ADC), T1, and T2 were also acquired, alongside 31P magnetic resonance spectroscopy data. Treated mice showed an inhibited tumour growth rate, decreased APT and increased ADC, compared with control mice, which could be due to changes in protein homeostasis as a result of proteasome inhibition by the drug.

Kannie WY Chan^1,2, Lu Jiang³, Jannie P Wijnen³, Guanshu Liu^1,2, Tiffany Greenwood¹, Menglin Chen¹, Peter CM van Zijl^1,2, Michael T McMahon^1,2, and Kristine Glunde^3,4
1Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Kennedy Krieger Institute, Baltimore, MD, United States,³Radiology, Division of Cancer Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴Sidney Kimmel Comprehensive Cancer Center, MD, United States

Altered metabolism is a hallmark of cancer, and in vivo assessment of metabolite levels is important for cancer diagnosis, development of anti-cancer treatments, and treatment monitoring. In the in vivo setting, MR spectroscopic imaging (MRSI) is not able to spatially resolve some of the metabolites that are important in cancer due to their relatively low concentrations. Chemical Exchange Saturation Transfer (CEST) is a molecular imaging approach that can improve detection sensitivity. Here we applied CEST to detect exchangeable protons of common cellular metabolites, showing that the metabolite CEST contrast in breast cell lines is inversely correlated with cancer cell aggressiveness.

Jae Mo Park¹, Sonal Josan¹, Taichang Jang², Milton Merchant², Ralph Hurd³, Dirk Mayer⁴, Lawrence Recht², and Daniel Spielman^1
1Radiology, Stanford University, Stanford, CA, United States, ²Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States,³GE Healthcare, CA, United States, ⁴Diagnostic Radiology and Nuclear Medicine, University of Maryland, MD, United States

We hypothesize that, in addition to changes in permeability, anti-VEGF drug also acutely and temporarily forces increased oxidative phosphorylation in glioma tissue due to nutrient depletion, increasing tumor vulnerability. Using an optimized 13C MRS imaging sequence, we were able to reproducibly image 13C-Bic in addition to 13C-Lac labeling using hyperpolarized [1-13C]Pyr in tumor-bearing rats, reflecting oxidative phosphorylation and glycolysis, respectively. After anti-VEGF treatment, Lac/Bic decreased significantly (at 3h post-treatment) and gradually increased back (24h and 48h post-treatment) in glioma while Lac/Bic did not have metabolic perturbation due to the drug. The increased Lac/Bic at 24h and 48h relatve to 3h suggests this might be a temporary phenomenon. We suggest that real time Bic measurements may provide both a useful biomarker for anti-angiogenic therapies and a potentially exploitable therapeutic strategy.

Hyeon-Man Baek^1,2, Yun-Ju Lee¹, Gregory Hyung Jin Park¹, Eun-Hee Kim¹, and Chaejoon Cheong^1,2
1Division of MR Research, Korea Basic Science Institute, Ochang, Chungbuk, Korea, ²Department of Bio-Analytical Science, University of Science & Technology, Yuseong-gu, Daejeon, Korea

We present here that the data analysis of 1H- and 13C-NMR spectra of the cell extracts showed a significant increase in the concentration of the 2HG in IDH mutated cells, but not in IDH wild type cells and mutant IDH cells with low transfection efficiency. In particular, 2HG-C5 labeling peaks from 13C-substrate were well separated from other metabolites (e.g., glutamate C-5 at 182.04, lactate C-1 at 183.23 ppm, etc.) in the 900MHz 1H-NMR spectra. This result demonstrates that 2HG can be actively being produced during the 24h period of [U-13C]glucose substrate feeding.

Jose Luis Izquierdo Garcia¹, Pia Eriksson¹, Cai Larry¹, Myriam Chaumeil¹, Russell O Pieper², Joanna J Phillips², and Sabrina M Ronen^1
1Radiology, UCSF, San Francisco, CA, United States, ²Neurological Surgery, Helen Diller Research Center, UCSF, San Francisco, CA, United States

Mutations in Isocitrate dehydrogenase (IDH1) have been reported in over 70% of low-grade gliomas and secondary glioblastomas. In this study, the metabolism of live U87IDHmut and U87IDHwt cells was probed by thermally and Hyper-polarized (HP) 13C-MRS. HP-1,2-13C Piruvic Acid MRS showed a drop in 5-13C glutamate production and an increase in lactate and alanine production. 1-13C glucose infusion resulted in a drop of glutamate in U87IDHmut cells whereas glucose uptake was not significant difference. The increase in lactate and alanine and the decrease of glutamate production in U87IDHmut cells indicate that TCA down-regulation is a major effect of IDH mutation.

Leslie R. Euceda^1,2, Tonje H. Haukaas^1,2, Guro F. Giskeødegård¹, Marit Krohn^2,3, Ellen Schlichting⁴, Rolf Kåresen^2,4, Sandra Nyberg^2,3, Kristine Kleivi Sahlberg^2,3, Anne-Lise Børresen-Dale^2,3, and Tone F. Bathen^1,2
1Department of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Trondheim, Norway, ²K.G. Jebsen Center for Breast Cancer Research, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway, ³Department of Genetics, Institute for Cancer Research Oslo University Hospital, The Norwegian Radium Hospital, Norway, ⁴Department of Surgery, Oslo University Hospital, Ullevål, Oslo, Norway

Metabolic subgroups resulting from hierarchical clustering of MR metabolic profiles from a large cohort of breast tumor biopsies were combined with data from gene expression and reverse phased protein arrays to search for any relationship between metabolic profiles and molecular subtypes. No such relationships were established, which might make it possible for a more refined division of subtypes into subclasses based on metabolic differences. Bridging information from several molecular levels in the same tumor may improve our knowledge about various classes of breast cancer that may contribute to personalized treatment.

Guro Fanneløb Giskeødegård^1,2, Maria Dung Cao^1,2, Santosh Lamichhane³, Beathe Sitter⁴, Anna Bofin⁵, Steinar Lundgren², Hans Fjøsne², and Tone Frost Bathen^1
1Dept. of Circulation and Medical Imaging, NTNU, Trondheim, Norway, ²St. Olavs University Hospital, Trondheim, Norway, ³Department of Food Science, Aarhus University, Denmark, ⁴Sør-Trøndelag University College, Norway, ⁵NTNU, Trondheim, Norway

Triple negative breast cancer (TNBC), characterized by estrogen receptor (ER), progesterone receptor (PgR) and HER2 negativity, represents 15-20% of all breast cancer cases. TNBC is associated with more aggressive and higher grade tumors and poor prognosis. Current treatment options for TNCB are few and the responses are often insufficient. Novel molecular targets for the treatment of TNBC are needed to improve treatment care and survival of this breast cancer subgroup. The purpose of this study was to characterize metabolic differences between TNBC as compared to triple positive breast cancer and to identify potential molecular markers of TNBC tumors for targeted treatment.

Yan Lin¹, ChengKang Liu¹, Zhiwei Shen¹, and Renhua Wu^1
1Radiology Department, Second Affiliated Hospital, Shantou University Medical College, Shantou City, Guangdong Province, China

This present study is a NMR-based metabolomics approaches coupled with pattern recognition methods to evaluate the ability to characterize the metabolic ¡°fingerprint¡± of fecal extracts from patients with ulcerative colitis (UC) and colorectal cancer (CRC). The most significant metabolites for classification include short-chain fatty acids, alanine, isoleucine, leucine, valine, glutamate, glycerol and the spectra in the aromatic region (6.6¨C8.2ppm), suggesting changes in the gut microbial community or malabsorption. This work shows the potential of MR-based metabolomics of fecal extracts in providing useful non-invasive diagnostic information for UC and CRC diseases and may further our understanding of colonic cancer mechanisms.