fumarates and Adenocarcinoma

Adenylosuccinate lyase (ADSL) is an enzyme that plays important roles in de novo purine synthesis. Although ADSL was reported to be upregulated in various malignancies, such as colorectal, breast, and prostate cancer, as well as gliomas, the mechanism by which elevated ADSL expression contributes to cancer has not been elucidated. We previously performed a shotgun proteomics analysis to characterize specific proteins associated with the properties of the aldehyde dehydrogenase (ALDH)-high cell population, which was reported to be involved in tumorigenic potential, and showed that ADSL expression is upregulated in the ALDH-high population of endometrial cancer. Here, we showed that ADSL is involved in endometrial cancer aggressiveness by regulating expression of killer cell lectin-like receptor C3 (KLRC3), which is a receptor expressed on natural killer cells. Immunohistochemical analysis indicated that ADSL expression increased as endometrioid carcinoma specimens became more poorly differentiated and higher degree of primary tumor progression. Knockdown of ADSL in endometrial cancer cells decreased cell proliferation, migration, and invasive capability, and caused the cells to adopt a more rounded shape. DNA microarray analysis and quantitative real-time PCR showed that KLRC3 expression was decreased in ADSL knockdown cells. Knockdown of KLRC3 in endometrial cancer cells resulted in the same phenotype as knockdown of ADSL. Moreover, fumarate, which could be produced by ADSL and was recently shown to be an oncometabolite, recovered KLRC3 expression in ADSL knockdown cells, suggesting that fumarate produced by ADSL could regulate KLRC3 expression. Our findings indicate that ADSL enhances cell proliferation, migration, and invasive capability through regulation of KLRC3 expression by fumarate.

Topics: Adenocarcinoma; Adenylosuccinate Lyase; Cell Line, Tumor; Cell Movement; Cell Proliferation; Endometrial Neoplasms; Female; Fumarates; Humans; Neoplasm Invasiveness; NK Cell Lectin-Like Receptor Subfamily C

No clinically validated biomarkers exist to image tumor responses to antiangiogenic therapy. Here, we report the utility of hyperpolarized (13)C magnetic resonance spectroscopy (MRS) to detect the early effects of anti-VEGF therapy. In two colorectal cancer xenograft models, displaying differential sensitivity to VEGF blockade, we compared hyperpolarized MRS with measurements of tumor perfusion using dynamic contrast agent-enhanced (DCE)-MRI and tumor cellularity using diffusion-weighted MRI of the apparent diffusion coefficient (ADC) of tissue water. In tumors sensitive to anti-VEGF therapy, (13)C flux between hyperpolarized [1-(13)C]pyruvate and [1-(13)C]lactate decreased after anti-VEGF therapy and correlated with reduced perfusion. Production of [1,4-(13)C(2)]malate from hyperpolarized [1,4-(13)C(2)]fumarate increased in parallel with tumor cell necrosis, preceding any change in tumor ADC. In contrast, tumors that were less sensitive to anti-VEGF therapy showed an increase in (13)C flux from hyperpolarized [1-(13)C]pyruvate and an increase in uptake of a gadolinium contrast agent, whereas tumor ADC decreased. Increased label flux could be explained by vascular normalization after VEGF blockade, increasing delivery of hyperpolarized [1-(13)C]pyruvate as observed. Despite the minimal response of these tumors to treatment, with only a minor increase in necrosis observed histologically, production of [1,4-(13)C(2)]malate from hyperpolarized [1,4-(13)C(2)]fumarate in therapy-resistant tumors also increased. Together, our findings show that hyperpolarized (13)C MRS detects early responses to anti-VEGF therapy, including vascular normalization or vascular destruction and cell death.

Topics: Adenocarcinoma; Angiogenesis Inhibitors; Animals; Antibodies, Monoclonal, Humanized; Bevacizumab; Carbon Isotopes; Cell Line, Tumor; Colorectal Neoplasms; Female; Fumarates; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Mice; Mice, SCID; Pyruvates; Vascular Endothelial Growth Factor A

The recent introduction of a dynamic nuclear polarisation technique has permitted noninvasive imaging of tumour cell metabolism in vivo following intravenous administration of (13)C-labelled cell substrates.. Changes in hyperpolarised [1-(13)C]pyruvate and [1,4-(13)C(2)]fumarate metabolism were evaluated in both MDA-MB-231 cells and in implanted MDA-MB-231 tumours following doxorubicin treatment.. Treatment of MDA-MB-231 cells resulted in the induction of apoptosis, which was accompanied by a decrease in hyperpolarised (13)C label flux between [1-(13)C]pyruvate and lactate, which was correlated with a decrease in the cellular NAD(H) coenzyme pool. There was also an increase in the rate of fumarate conversion to malate, which accompanied the onset of cellular necrosis. In vivo, the decrease in (13)C label exchange between pyruvate and lactate and the increased flux between fumarate and malate, following drug treatment, were shown to occur in the absence of any detectable change in tumour size.. We show here that the early responses of a human breast adenocarcinoma tumour model to drug treatment can be followed by administration of both hyperpolarised [1-(13)C]pyruvate and [1,4-(13)C(2)]fumarate. These techniques could be used, therefore, in the clinic to detect the early responses of breast tumours to treatment.

Topics: Adenocarcinoma; Animals; Breast Neoplasms; Calcium Dobesilate; Carbon Isotopes; Cell Death; Cell Line, Tumor; Female; Fumarates; Humans; Mice; Mice, SCID; Pyruvic Acid

The inhibitory effect of fumaric acid (FA) on carcinogenesis by potassium 1-methyl-7-[2-(5-nitro-2-furyl)vinyl]-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate (trans, NFN) was examined histologically with male ICR/JCL mice. NFN was fed to mice at a dose level of 0.012% in the diet for 14 weeks. These mice were then divided into 2 groups. One group was given a basal diet, and the other group was given a diet containing 1% FA in the subsequent 39 weeks. In the group of 30 mice fed NFN alone, squamous cell carcinomas were found in the stomachs of 7 mice, multiple papillomas in the stomachs of 13 mice, and multiple and large papillary adenocarcinomas in the lungs of 27 animals. The administration of FA suppressed the NFN-induced stomach and lung carcinogenesis. In the group of 32 mice fed NFN and FA, no stomach tumors developed except 1 early-stage of squamous cell carcinoma. In the lungs, only a small focus of mild atypical hyperplasia and a few early-stage adenocarcinomas were noted in 7 and 11 animals, respectively.

Topics: Adenocarcinoma; Animals; Carcinoma, Squamous Cell; Drug Interactions; Fumarates; Lung Neoplasms; Mice; Mice, Inbred ICR; Nalidixic Acid; Papilloma; Stomach Neoplasms

Topics: Adenocarcinoma; Animals; Citric Acid Cycle; Fumarates; In Vitro Techniques; Ketoglutaric Acids; Malates; Male; Mice; NAD; Neoplasm Transplantation; Neoplasms, Experimental; Oxygen Consumption; Pyruvates; Salivary Gland Neoplasms; Stimulation, Chemical; Submandibular Gland; Succinates

Topics: Adenocarcinoma; Animals; Carbon Dioxide; Citric Acid Cycle; Fumarates; Glucose; Glycolysis; Mice; NAD; Neoplasm Transplantation; Neoplasms, Experimental; Oxidation-Reduction; Oxygen Consumption; Pyruvates; Salivary Gland Neoplasms; Submandibular Gland