Therese Halvorsen Røst

Publications (13) View all

• Article: Novel phospholipid analogues of pan-PPAR activator tetradecylthioacetic acid are more PPAR alpha selective.

  Yushma Bhurruth-Alcor, Therese H Rost, Michael R Jorgensen, Rajender, Melanie Müller, Jon Skorve, Rolf K Berge, Andrew D Miller
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  ABSTRACT: Tetradecylthioacetic acid (TTA) is a modified fatty acid that appears to improve insulin sensitivity, lower blood lipid levels, enhance fatty acid oxidation and promote anti-inflammatory action in vivo, through mechanisms partly dependent upon peroxisome proliferator-activated receptors (PPARs). In order to improve the biological efficacy of TTA as a PPAR agonist, two novel phospholipid analogue lyso tetradecylthioacetyl-L-alpha-phosphatidylcholine and di-tetradecylthioacetyl-L-alpha-phosphatidylglycerol have been developed. Here we report on the syntheses of these novel phospholipids and their relative potential to act as PPAR agonists in vitro, in comparison to TTA and other positive controls.
  Bioorganic & medicinal chemistry letters 02/2010; 20(3):1252-5. · 2.65 Impact Factor
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  Available from: Jennifer Gjerde

  Article: Steroid receptor coactivators, HER-2 and HER-3 expression is stimulated by tamoxifen treatment in DMBA-induced breast cancer.

  Line L Haugan Moi, Marianne Hauglid Flågeng, Jennifer Gjerde, Andre Madsen, Therese Halvorsen Røst, Oddrun Anita Gudbrandsen, Ernst A Lien, Gunnar Mellgren
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  ABSTRACT: Steroid receptor coactivators (SRCs) may modulate estrogen receptor (ER) activity and the response to endocrine treatment in breast cancer, in part through interaction with growth factor receptor signaling pathways. In the present study the effects of tamoxifen treatment on the expression of SRCs and human epidermal growth factor receptors (HERs) were examined in an animal model of ER positive breast cancer. Sprague-Dawley rats with DMBA-induced breast cancer were randomized to 14 days of oral tamoxifen 40 mg/kg bodyweight/day or vehicle only (controls). Tumors were measured throughout the study period. Blood samples and tumor tissue were collected at sacrifice and tamoxifen and its main metabolites were quantified using LC-MS/MS. The gene expression in tumor of SRC-1, SRC-2/transcription intermediary factor-2 (TIF-2), SRC-3/amplified in breast cancer 1 (AIB1), ER, HER-1, -2, -3 and HER-4, as well as the transcription factor Ets-2, was measured by real-time RT-PCR. Protein levels were further assessed by Western blotting. Tamoxifen and its main metabolites were detected at high concentrations in serum and accumulated in tumor tissue in up to tenfolds the concentration in serum. Mean tumor volume/rat decreased in the tamoxifen treated group, but continued to increase in controls. The mRNA expression levels of SRC-1 (P = 0.035), SRC-2/TIF-2 (P = 0.002), HER-2 (P = 0.035) and HER-3 (P = 0.006) were significantly higher in tamoxifen treated tumors compared to controls, and the results were confirmed at the protein level using Western blotting. SRC-3/AIB1 protein was also higher in tamoxifen treated tumors. SRC-1 and SRC-2/TIF-2 mRNA levels were positively correlated with each other and with HER-2 (P ≤ 0.001), and the HER-2 mRNA expression correlated with the levels of the other three HER family members (P < 0.05). Furthermore, SRC-3/AIB1 and HER-4 were positively correlated with each other and Ets-2 (P < 0.001). The expression of SRCs and HER-2 and -3 is stimulated by tamoxifen treatment in DMBA-induced breast cancer. Stimulation and positive correlation of coactivators and HERs may represent an early response to endocrine treatment. The role of SRCs and HER-2 and -3 should be further studied in order to evaluate their effects on response to long-term tamoxifen treatment.
  BMC Cancer 06/2012; 12:247. · 3.01 Impact Factor
• Article: Synthesis of novel PPARα/γ dual agonists as potential drugs for the treatment of the metabolic syndrome and diabetes type II designed using a new de novo design program PROTOBUILD.

  Yushma Bhurruth-Alcor, Therese Røst, Michael R Jorgensen, Christos Kontogiorgis, Jon Skorve, Robert G Cooper, Joseph M Sheridan, William D O Hamilton, Jonathan R Heal, Rolf K Berge, Andrew D Miller
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  ABSTRACT: Peroxisome proliferator activated receptors (PPARs) have been shown to have critical roles in fatty acid oxidation, triglyceride synthesis, and lipid metabolism - making them an important target in drug discovery. Here we describe the in silico design, synthesis and in vitro characterisation of a novel series of 2,5-disubstituted indoles as PPARα/γ dual agonists. PPAR activation assays are performed with known agonists diazabenzene (WY14.643), aminopyridine (BRL49653) and bisaryl (L165.041), as positive controls. All the indole compounds synthesized are found to be active PPARα and PPARγ agonists, with particular efficacy from those with 2-naphthylmethyl substitution. This is a useful demonstration of a new de novo design methodology implemented by the protobuild program and its ability to rapidly produce novel modulators for a well characterized drug target.
  Organic & Biomolecular Chemistry 02/2011; 9(4):1169-88. · 3.70 Impact Factor
• Article: Tetradecylthioacetic acid attenuates dyslipidaemia in male patients with type 2 diabetes mellitus, possibly by dual PPAR-alpha/delta activation and increased mitochondrial fatty acid oxidation.

  K Løvås, T H Røst, J Skorve, R J Ulvik, O A Gudbrandsen, P Bohov, A J Wensaas, A C Rustan, R K Berge, E S Husebye
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  ABSTRACT: We previously demonstrated that a modified fatty acid, tetradecylthioacetic acid (TTA), improves transport and utilization of lipids and increases mitochondrial fatty acid oxidation in animal and cell studies. We conducted an exploratory study of safety and effects of this novel drug in patients with type 2 diabetes mellitus and investigated the mechanism of action in human cell lines. Sixteen male patients with type 2 diabetes mellitus received 1 g TTA daily for 28 days in an open-labelled study, with measurement of parameters of lipid metabolism, glucose metabolism and safety (ClinicalTrials.gov NCT00605787). The mechanism of action was further investigated in a human liver cell line (HepG2) and in cultured human skeletal muscle cells (myotubes). Mean LDL cholesterol level declined from 4.2 to 3.7 mmol/l (p < 0.001), accompanied by increased levels of the HDL apolipoproteins A1 and A2, and a decline in LDL/HDL ratio from 4.00 to 3.66 (p = 0.008). Total fatty acid levels declined, especially the fraction of the polyunsaturated n-3 fatty acids docosahexaenoic acid (-13%, p = 0.002) and eicosapentaenoic acid (-10%, p = 0.07). Glucose metabolism was not altered and the drug was well tolerated. In cultured liver cells, TTA acted as a pan-PPAR agonist with predominant PPAR-alpha and PPAR-delta activation at low TTA concentrations. In myotubes, TTA and a PPAR-delta agonist, but not the PPAR-alpha or PPAR-gamma agonists, increased the fatty acid oxidation. We demonstrate for the first time that TTA attenuates dyslipidaemia in patients with type 2 diabetes mellitus. These effects may occur through mechanisms involving PPAR-alpha and PPAR-delta activation, resulting in increased mitochondrial fatty acid oxidation.
  Diabetes Obesity and Metabolism 04/2009; 11(4):304-14. · 3.38 Impact Factor
• Article: Synthesis and analysis of novel glycerolipids for the treatment of metabolic syndrome.

  Michael R Jorgensen, Yushma Bhurruth-Alcor, Therese Røst, Pavol Bohov, Melanie Müller, Cristina Guisado, Kostas Kostarelos, Endre Dyrøy, Rolf K Berge, Andrew D Miller, Jon Skorve
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  ABSTRACT: Tetradecylthioacetic acid (TTA) 1 is a peroxisome proliferator-activated receptor (PPAR) agonist found to improve insulin sensitivity, lower blood lipid levels, enhance fatty acid oxidation, and promote anti-inflammation in vivo. In an attempt to enhance these properties, two key thioether fatty acid (Thefa) lipids, ditetradecylthioacetyl phosphatidylcholine 2 and tritetradecylthioacetyl glycerol 3, are synthesized and administered po to male Wistar rats at two different doses to study and compare metabolic outcomes relative to the administration of 1 alone after 6 days. Liposomal formulations of 1 and 2 are also prepared to evaluate acute metabolic responses (at 3 h) post i.v. injection. Across all metrics measured, 1-induced responses post po administration are in line with previous data. Responses induced from 3 are mostly equivalent to 1-induced responses. By contrast, 2-induced responses almost always outperform those of 1 and 3. Therefore, 2 may represent a new lead for the treatment of metabolic syndrome.
  Journal of Medicinal Chemistry 02/2009; 52(4):1172-9. · 4.80 Impact Factor