TRbeta is the critical thyroid hormone receptor isoform in T3-induced proliferation of hepatocytes and pancreatic acinar cells.

BACKGROUND & AIMS: Thyroid hormones elicit many cellular and metabolic effects in various organs. Most of these actions, including mitogenesis, are mediated by the thyroid hormone 3,5,3'-triiodo-l-thyronine (T3) nuclear receptors (TRs). They are transcription factors, expressed as different isoforms encoded by the TRalpha and TRbeta genes. Here, experiments were performed to determine whether (i) T3-induces hepatocyte proliferation in mouse liver and pancreas, and, (ii) which TR isoform, is responsible for its mitogenic effect. METHODS: Cell proliferation was measured by bromodeoxyuridine (BrdU) incorporation after T3 or the TRbeta agonist GC-1 in liver and pancreas of CD-1, C57BL, or TRalpha(0/0) mice. Cell cycle-associated proteins were measured by Western blot. RESULTS: T3 added to the diet at a concentration of 4 mg/kg caused a striking increase in BrdU incorporation in mouse hepatocytes. Increased BrdU incorporation was associated with enhanced protein levels of cyclin D1 and PCNA and decreased levels of p27. Treatment with GC-1, a selective agonist of the TRbeta isoform, also induced a strong mitogenic response of mouse hepatocytes and pancreatic acinar cells which was similar to that elicited by T3. Finally, treatment with T3 of mice TRalpha(0/0) induced a proliferative response in the liver and pancreas, similar to that of their wild type counterpart. CONCLUSIONS: These results demonstrate that T3 is a powerful inducer of cell proliferation in mouse liver and suggest that the beta-isoform is responsible for the hepatomitogenic activity of T3. The same isoform seems to also mediate the proliferation of mouse pancreatic acinar cells.

Synthesis and evaluation of anticancer activity of 2-arylamino-6-trifluoromethyl-3-(hydrazonocarbonyl)pyridines.

The synthesis and anticancer activity of 2-arylamino-6-trifluoromethyl-3-(hydrazonocarbonyl)pyridines is described. The new trifluoromethylpyridine derivatives were evaluated for their anticancer activity toward human cancer cell lines by the National Cancer Institute (NCI). Most of them had excellent growth inhibition activity, having GI(50) values in the low micromolar to nanomolar concentration range. The most potent 2,6-dichlorobenzaldehydehydrazone 29 inhibited the growth of all tested cancer cell lines with nanomolar potency, and did not show animal toxicity. Hydrazone 29 has been selected by the Biological Evaluation Committee of NCI for testing in vivo Hollow Fiber Assay.

2-Acylhydrazino-5-arylpyrrole derivatives: synthesis and antifungal activity evaluation.

The synthesis and antifungal activity of 2-acylhydrazino-5-arylpyrroles 21-62 are described. Pyrrole derivatives 21-62 were evaluated for their antifungal activity towards Candida albicans ATCC 10231 and three Candida non-albicans isolated from clinical specimens. Most of them showed very good antifungal activities against Candidae, having MIC values in the 0.39-3.12 microg/mL range and enhanced inhibition potency as compared to that of fluconazole. In addition, some of the most active compounds were tested for cytotoxic activities against breast (MCF-7), lung (H-460), and central nervous system (SF-268) human cancer cell lines with the NCI anticancer drug screen. The activity of pyrroles described in this paper, along with the low toxicity, shows promise for the future development of non-toxic new antimycotic agents. The relationship between functional group variation and biological activity of the evaluated compounds is also discussed.

Thyroid hormone (T3) and TRbeta agonist GC-1 inhibit/reverse nonalcoholic fatty liver in rats.

Nonalcoholic fatty liver disease is the most common noninfectious liver disease in clinical practice, and there is an increasing need for new therapeutic approaches for the treatment of this liver disease. Here, we examined the effect of the thyroid hormone triiodothyronine (T3) and the agonist of the thyroid hormone receptor beta isoform (TRbeta), GC-1, on fatty liver and steatohepatitis induced in rodents by a choline-methionine deficient (CMD) diet. Male Fischer 344 rats fed a CMD diet for 1 wk developed a marked fatty liver and mild hepatitis. Concurrent administration of T3 resulted in a complete prevention of the fatty change associated with increased fatty acid mitochondrial and peroxisomal beta-oxidation. To investigate whether T3 could also reverse fully established fatty liver, rats were fed a CMD diet for 10 wk and then cofed T3 for 1 wk. Coadministration of T3 resulted in a complete regression of liver steatosis associated with a decrease of lipid peroxidation, cyclooxygenase-2 expression, and activation of phospho-STAT3 and phospho-SAPK/JNK. Finally, additional experiments showed that GC-1, which has no significant side effects on heart rate, prevented and reverted CMD-induced fat accumulation, and ameliorated steatohepatitis. These results indicate that TR agonists have the potential to inhibit or reverse hepatic steatosis induced by a nutritional model.

Synthesis and evaluation of antitumoral activity of ester and amide derivatives of 2-arylamino-6-trifluoromethyl-3-pyridinecarboxylic acids.

The synthesis and antitumoral activity of ester and amide derivatives of 2-arylamino-6-trifluoromethyl-3-pyridinecarboxylic acids 8-58 is described. Trifluoromethylpyridine derivatives 8-58 were evaluated for their anticancer activity toward human tumoral cell lines by the National Cancer Institute (NCI). Most of them possess encouraging anticancer activity, having GI(50) values in the low micromolar to nanomolar concentration range. The 3,4,5-trimethoxyphenylamide 44 was the most active, and it is now under review by NCI Biological Evaluation Committee for possible further studies.

Synthesis and in vitro antitumoral activity of new 3,5-dicyanopyridine derivatives.

A new series of 2-amino-4-aryl-6-dialkylamino-3,5-dicyanopyridines, 20-47, were synthesized in satisfactory overall yield, through a simple synthetic strategy using 3-amino-3-(dialkylamino)-propenenitriles 1 and 2 as key intermediates. 3,5-Dicyanopyridine derivatives 20-47 were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancers. Some of the newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-6) M level and in some cases at 10(-8) M concentration.

Synthesis and in vitro antitumoral activity of new hydrazinopyrimidine-5-carbonitrile derivatives.

A new series of 2-amino-6-(2-alkyl or arylidenehydrazinyl)-4-(dialkylamino)pyrimidine-5-carbonitriles, 5-24, were synthesized in satisfactory overall yield, using 2-amino-4-(dialkylamino)-6-hydrazino-5-pyrimidinecarbonitriles 3, 4, as key intermediates, by applying classical synthetic methods to construct the hydrazone moiety at C-6 of the pyrimidine ring. Hydrazinopyrimidine derivatives 5-24 were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancers. Some of the newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-5)M level and in some cases at 10(-7)M concentrations.

Synthesis of new N-(2-(trifluoromethyl)pyridin-4-yl)anthranilic acid derivatives and their evaluation as anticancer agents.

The N-(2-(trifluoromethyl)pyridin-4-yl)anthranilic acid 6 and a series of its ester and amide derivatives were synthesized and evaluated for their in vitro cytotoxic activity against human cancer cells. Ester derivatives 13 and 18 exhibited potent growth inhibitory activity with GI(50) values at nanomolar concentrations. Among amide derivatives, N-anthraniloylglycinate 19 shown moderate inhibitory activity in the full panel cancer cell line screening.

Synthesis of new 2-arylamino-6-trifluoromethylpyridine-3-carboxylic acid derivatives and investigation of their analgesic activity.

A new series of 2-arylamino-6-trifluoromethyl-3-carboxylic acid derivatives was synthesized and assayed in vivo for their analgesic properties by means of writhing test in rats. When compared to aspirin, ibuprofen and flufenamic acid some of the new compounds exhibited a comparable or improved analgesic activity and a lower ulcerogenic effect.

Synthesis and in vitro antitumoral activity of new N-phenyl-3-pyrrolecarbothioamides.

A new series of N-phenylpyrrolecarbothioamides were obtained from base catalyzed intramolecular cyclization of 3-amino-3-(alkyl or arylamino)propenethioamides. Pyrrole derivatives were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancer. Some of newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at 10(-6) M level and in some case at 10(-8) M concentrations.