A Synergistic Anti-Cancer Effect of Troglitazone and Lovastatin in a Human Anaplastic Thyroid Cancer Cell Line and in a Mouse Xenograft Model.

Anaplastic thyroid cancer (ATC) is a malignant subtype of thyroid cancers and its mechanism of development remains inconclusive. Importantly, there is no effective strategy for treatment since ATC is not responsive to conventional therapies, including radioactive iodine therapy and thyroid-stimulating hormone suppression. Here, we report that a combinational approach consisting of drugs designed for targeting lipid metabolism, lovastatin (an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, HMGCR) and troglitazone (an agonist of peroxisome proliferator-activated receptor gamma, PPARγ), exhibits anti-proliferation in cell culture systems and leads to tumor regression in a mouse xenograft model. The composition contains a sub-lethal concentration of both drugs and exhibits low toxicity to certain types of normal cells. Our results support a hypothesis that the inhibitory effect of the combination is partly through a cell cycle arrest at G0/G1 phase, as evidenced by the induction of cyclin-dependent kinase inhibitors, p21cip and p27kip, and the reduction of hyperphosphorylated retinoblastoma protein (pp-Rb)-E2F1 signaling. Therefore, targeting two pathways involved in lipid metabolism may provide a new direction for treating ATC.

Simvastatin Inhibits Cell Proliferation and Migration in Human Anaplastic Thyroid Cancer.

Malignant human anaplastic thyroid cancer (ATC) is pertinacious to conventional therapies. The present study investigated the anti-cancer activity of simvastatin and its underlying regulatory mechanism in cultured ATC cells. Simvastatin (0-20 µM) concentration-dependently reduced cell viability and relative colony formation. Depletions of mevalonate (MEV) and geranylgeranyl pyrophosphate (GGpp) by simvastatin induced G1 arrest and increased apoptotic cell populations at the sub-G1 phase. Adding MEV and GGpp prevented the simvastatin-inhibited cell proliferation. Immunoblotting analysis illustrated that simvastatin diminished the activation of RhoA and Rac1 protein, and this effect was prevented by pre-treatment with MEV and GGpp. Simvastatin increased the levels of p21cip and p27kip proteins and reduced the levels of hyperphosphorylated-Rb, E2F1 and CCND1 proteins. Adding GGpp abolished the simvastatin-increased levels of p27kip protein, and the GGpp-caused effect was abolished by Skp2 inhibition. Introduction of Cyr61 siRNA into ATC cells prevented the epidermal growth factor (EGF)-enhanced cell migration. The EGF-induced increases of Cyr61 protein expression and cell migration were prevented by simvastatin. Taken together, these results suggest that simvastatin induced ATC proliferation inhibition through the deactivation of RhoA/Rac1 protein and overexpression of p21cip and p27kip, and migration inhibition through the abrogation of Cyr61 protein expression.

Involvement of cysteine-rich protein 61 in the epidermal growth factor-induced migration of human anaplastic thyroid cancer cells.

Anaplastic thyroid cancer (ATC) is among the most aggressive types of malignant cancer. Epidermal growth factor (EGF) plays a crucial role in the pathogenesis of ATC, and patients with thyroid carcinoma typically exhibit increased cysteine-rich protein 61 (Cyr61). In this study, we found that EGF treatment induced cell migration, stress fiber formation, Cyr61 mRNA and protein expressions, and Cyr61 protein secretion in ATC cells. The recombinant Cyr61 protein significantly induced cell migration; however, inhibition of Cyr61 activity by a Cyr61-specific antibody abrogated EGF-induced cell migration. EGF treatment also affected epithelial-to-mesenchymal transition (EMT)-related marker protein expression, as evidenced by an increase in vimentin and a decrease in E-cadherin expression. Inhibition of Cyr61 expression by Cyr61 siRNA decreased cell migration and reversed the EMT-related marker protein expression. EGF treatment increased the phosphorylation of the extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB), and finally activated Cyr61 promoter plasmid activity. Our results suggest that Cyr61 is induced by EGF through the ERK/CREB signal pathway and that it plays a crucial role in the migration and invasion of ATC cells; moreover, Cyr61 might be a therapeutic target for metastatic ATC.

Isolation and synthesis of a bioactive benzenoid derivative from the fruiting bodies of Antrodia camphorata.

A new enynyl-benzenoid, antrocamphin O (1,4,7-dimethoxy-5-methyl-6-(3'-methylbut-3-en-1-ynyl)benzo[d][1,3]dioxide), and the known benzenoids antrocamphin A and 7-dimethoxy-5-methyl-1,3-benzodioxole, were isolated from the fruiting bodies of Antrodia camphorata (Taiwanofungus camphoratus). The structure of antrocamphin O was unambiguously assigned by the analysis of spectral data (including 1D and 2D NMR, high-resolution MS, IR, and UV) and total synthesis. Compound 1 was prepared through the Sonogashira reaction of 5-iodo-4,7-dimethoxy-6-methylbenzene and 2-methylbut-1-en-3-yne as the key step. The benzenoids were tested for cytotoxicity against the HT29, HTC15, DLD-1, and COLO 205 colon cancer cell lines, and activities are reported herein.

Tracheal Reconstruction with the Scaffolded Cartilage Sheets in an Orthotopic Animal Model.

Tracheal reconstruction remains challenged in clinical. We aimed to fabricate scaffolded cartilage sheets with rigid and elastic supports for tracheal reconstruction. The chondrocyte cell infiltration activity was examined in poly-caprolactone sheet scaffolds with various thicknesses and pore sizes after seeding cells on the top surface of the sheet scaffolds. The expression of cartilage-related genes and accumulation of sulfated glycosaminoglycans were elevated in the cell-scaffold composites upon chondrogenic induction. The thicker cartilage sheets represented stronger mechanical properties than the thinner cartilage sheets. Two different cartilage sheets were orthotopically implanted into a trachea in a rabbit model for 2, 4, and 16 weeks. Cartilage-related sulfated glycosaminoglycans and type II collagen macromolecules were stably expressed in the tracheal implants. However, the invasive migration of fibrous tissue and profibrotic collagen fibers into cartilage implants and the peripheral space surrounding the implants were elevated in a time-dependent manner. At week 16 postimplantation, airway stenosis was noticed under the thicker sheet implants, but not the thinner implants, suggesting that the thinner (1 mm thick) scaffolded cartilage sheet was an optimal candidate for tracheal reconstruction in this study. Finally, cartilage sheets could be a reconstructive therapy candidate applied to reconstruct defects in the trachea and other tissues composed of cartilage. Impact statement Tissue engineering is a promising approach to generate biological substitutes. We aimed to develop cartilage sheets as tracheal prosthesis used in tracheal reconstruction or regional repairing in the animal model. The formation of microvessels and the dynamics of reepithelialization were monitored for 16 weeks in tracheal implants of the engineered cartilage sheets. In this study, it was demonstrated that the tissue-engineered cartilage sheets are potential substitutes applied in the reconstruction of the trachea and other tissues composed of cartilage tissue. The cartilage sheets were thought of as biomaterials for personalized regenerative medicine since the dimensions, thickness, and pore sizes of cartilage sheets were tunable to fit the lesions that need to be reconstructed.

Tracheal reconstruction with pedicled tandem grafts engineered by a radial stretch bioreactor.

The engineering of tracheal substitutes is pivotal in improving tracheal reconstruction. In this study, we aimed to investigate the effects of biomechanical stimulation on tissue engineering tracheal cartilage by mimicking the trachea motion through a novel radial stretching bioreactor, which enables to dynamically change the diameter of the hollow cylindrical implants. Applying our bioreactor, we demonstrated that chondrocytes seeded on the surface of Poly (ε-caprolactone) scaffold respond to mechanical stimulation by improvement of infiltration into implants and upregulation of cartilage-specific genes. Further, the mechanical stimulation enhanced the accumulation of cartilage neo-tissues and cartilage-specific extracellular macromolecules in the muscle flap-remodeled implants and reconstructed trachea. Nevertheless, the invasion of fibrous tissues in the reconstructed trachea was suppressed upon mechanical loading.

Dipyridamole suppresses high glucose-induced osteopontin secretion and mRNA expression in rat aortic smooth muscle cells.

BACKGROUND: Diabetic patients are frequently afflicted with medial artery calcification, a predictor of cardiovascular mortality. Diabetes induced the expression of osteopontin in arterial vasculature, which is an indicator of disease progression in artery calcification and vascular stiffness. Signal transduction and strategies that suppress high glucose-induced osteopontin expression in arterial vascular smooth muscle cells is investigated. METHODS AND RESULTS: The incubation of rat aortic smooth muscle cells under high glucose concentration increased osteopontin protein secretion and mRNA expression. Treatment with dipyridamole decreased high glucose-induced osteopontin expression and secretion. Dipyridamole decreased glucose-induced osteopontin through inhibition of phosphodiesterase, thereby increasing intracellular levels of adenosine-3',5'-cyclic monophosphate (cAMP) and guanosine-3',5'-cyclic monophosphate (cGMP), and increased thioredoxin expression to inhibit the reactive oxygen species (ROS) system. Induction of osteopontin was reversed when cells were pretreated with N-[2-bromocinnamyl(amino)ethyl]-5-isoquinolinesulfonamide (H89, cAMP-dependent protein kinase inhibitor), KT5823 (cGMP-dependent protein kinase inhibitor), or dinitrochlorobenzene (thioredoxin reductase inhibitor). The antioxidant, N-acetyl-L-cysteine, suppressed glucose-induced osteopontin expression by decreasing ROS concentration. Both H89 and KT5823 downregulated thioredoxin expression. CONCLUSIONS: These results suggest a novel effect for dipyridamole to suppress high glucose-induced osteopontin protein secretion and mRNA expression. Dipyridamole has antioxidant properties and a phosphodiesterase inhibitor activity, which might be useful to ameliorate diabetic vasculopathy and its cardiovascular complications.

ETF-QO Mutants Uncoupled Fatty Acid ß-Oxidation and Mitochondrial Bioenergetics Leading to Lipid Pathology.

The electron-transfer flavoprotein dehydrogenase gene (ETFDH) that encodes the ETF-ubiquinone oxidoreductase (ETF-QO) has been reported to be the major cause of multiple acyl-CoA dehydrogenase deficiency (MADD). ETF-QO is an electron carrier that mainly functions in mitochondrial fatty acid ß-oxidation and the delivery of electrons to the ubiquinone pool in the mitochondrial respiratory chain. A high frequency of c.250G>A has been found in Taiwanese patients with late-onset MADD. We postulated that the ETFDH c.250G>A mutation may concomitantly impair fatty acid ß-oxidation and mitochondrial function. Using MADD patient-derived lymphoblastoid cells and specifically overexpressed ETFDH c.92C>T, c.250G>A, or coexisted c.92C>T and c.250G>A (c.92C>T + c.250G>A) mutated lymphoblastoid cells, we addressed the genotype-phenotype relationship of ETFDH variation in the pathogenesis of MADD. The decreased adenosine triphosphate synthesis, dissipated mitochondrial membrane potentials, reduced mitochondrial bioenergetics, and increased neutral lipid droplets and lipid peroxides were found in the MADD patient-derived lymphoblastoid cells. Riboflavin and/or coenzyme Q10 supplementation rescued cells from lipid droplet accumulation. All three mutant types, c.92C>T, c.250G>A, or c.92C>T + c.250G>A, had increased lipid droplet accumulation after treatment with palmitic acid. These results help to clarify the molecular pathogenesis of MADD as a result of the high frequency of the ETFDH c.250G>A and c.92C>T mutations.

Switch activation of PI-PLC downstream signals in activated macrophages with wortmannin.

Phosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P(2)) has been known to serve as a substrate for phosphatidylinositol 3-kinase (PI(3)K) and phosphoinositide-specific phospholipase C (PI-PLC), which can produce PtdIns(3,4,5)P(3) and inositol 1,4,5-trisphosphate (Ins(1,4,5)P(3)) and diacylglycerol (DAG), respectively. In this study, we elucidated the role of PI-PLC during the LPS-activated mouse macrophages RAW264.7 treated with PI(3)K inhibitor wortmannin. First, wortmannin treatment enhanced Ins(1,4,5)P(3) production and iNOS expression in LPS-activated macrophages. Inhibition of PI(3)K by p85 siRNA also showed an enhancement of iNOS expression. On the other hand, overexpression of PI(3)K by ras-p110 expression plasmid significantly decreased iNOS expression in LPS-activated macrophages. In addition, overexpression of wild-type or dominant-negative Akt expression plasmid did not affect the iNOS expression in LPS-activated macrophages. Second, treatment of PI-PLC inhibitor U73122 reversed the enhancement of iNOS expression, the increase of phosphorylation level of ERK, JNK and p38, and the increase of AP-1-dependent gene expression in wortmannin-treated and LPS-activated macrophages. However, NF-kappaB activity determined by EMSA assay and reporter plasmid assay did not change during LPS-activated macrophages with or without wortmannin. We propose that the inhibition of PI(3)K by wortmannin in mouse macrophages enhances the PI-PLC downstream signals, and subsequently increases the LPS induction of iNOS expression independently of Akt pathway.

Comparative anti-inflammatory characterization of wild fruiting body, liquid-state fermentation, and solid-state culture of Taiwanofungus camphoratus in microglia and the mechanism of its action.

Taiwanofungus camphoratus (syn. Antrodia camphorata), a medicinal mushroom in Taiwan, is reputed to provide several therapeutic benefits, but the wild fruiting body is very rare. In this study, we used Taiwanofungus camphoratus extracts from wild fruiting bodies and two types of artificial cultivation (solid-state culture and liquid-state fermentation) to examine their anti-inflammatory effects in microglia cells and their possible roles in protection against neurodegenerative diseases. First, EOC13.31 microglia was treated with various kinds of Taiwanofungus camphoratus extracts and lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) to evaluate the iNOS expression. Western blot and RT-PCR analysis showed that among the various kinds of extracts from wild fruiting bodies, methanol extracts were the most potent inhibitors of iNOS expression. Secondly, the potency of methanol extracts could be ranked as follows: extracts of wild fruiting body>solid-state culture>liquid-state fermentation. To clarify the mechanisms involved, methanol extracts from fruiting body were found to inhibit the phosphorylation of extracellular signal-regulated protein kinases (ERK), c-Jun NH2-terminal protein kinases (JNK) and signal transducer and activator of transcription-1 (STAT-1) induced by LPS/IFN-gamma. Methanol extracts from fruiting body also inhibited NF-kappaB activation through the prevention of inhibitor kappaB (IkappaB) degradation. Moreover, methanol extracts from wild fruiting body inhibited both the iNOS and cyclooxygenase-2 (COX-2) expression induced by beta-amyloid in microglia in a dose-dependent manner. In an animal model, we confirmed that methanol extracts from fruiting bodies were able to suppress ear edema, indicating that they have anti-inflammatory activity in vivo. These results suggest that Taiwanofungus camphoratus exhibits an anti-inflammatory activity that might contribute to the prevention of neurodegenerative diseases.

Terbinafine inhibits endothelial cell migration through suppression of the Rho-mediated pathway.

We showed previously that terbinafine, an allylamine with fungicidal activity, could inhibit angiogenesis by suppressing the endothelial cell proliferation. In the present study, we further showed that terbinafine (0-120 micromol/L) dose dependently inhibited the adhesion and migration of human umbilical vascular endothelial cells (HUVEC). Western blot analysis showed that terbinafine decreased the levels of Ras protein and membrane-bound RhoA protein. Moreover, the terbinafine-induced migration inhibition in HUVEC was prevented by pretreatment with farnesol or geranylgeraniol. Pretreatment of HUVEC with Ras inhibitor peptide or a ROCK (a kinase associated with RhoA for transducing RhoA signaling) inhibitor, Y27632, abolished the farnesol- or geranylgeraniol-induced prevention effect on the terbinafine-induced migration inhibition, respectively. These data suggest that the consuming or depletion of geranylgeranyl pyrophosphate and consequent suppression of protein geranylgeranylation and farnesylation, which is essential for activation of Rho GTPases and Ras, respectively, might account for the terbinafine-induced inhibition of HUVEC migration. The levels of phosphorylated focal adhesion kinase and paxillin protein and the mRNA levels of matrix metalloproteinase-2 and matrix metalloproteinase-9 were also decreased by terbinafine treatment. Taken together, these results indicate that suppression of Rho-mediated pathway might be involved in the signal transduction leading to the inhibition of cell migration caused by terbinafine in HUVEC.

Correction: Combined Treatment with Troglitazone and Lovastatin Inhibited Epidermal Growth Factor-Induced Migration through the Downregulation of Cysteine-Rich Protein 61 in Human Anaplastic Thyroid Cancer Cells.

[This corrects the article DOI: 10.1371/journal.pone.0118674.].

Oxysterol-binding protein-related protein 4L promotes cell proliferation by sustaining intracellular Ca2+ homeostasis in cervical carcinoma cell lines.

Oxsterol binding protein-related protein 4 (ORP4) is essential for cell proliferation, but the underlying mechanism is unclear. ORP4 is expressed as three variants, ORP4L, ORP4M and ORP4S. Here, we reported that silencing of ORP4L with specific small interfering RNA (siRNA) inhibited the proliferation of human cervical cancer cell lines C33A, HeLa and CaSki, the reverse effect being observed in ORP4L overexpressing cells. For molecular insight, we found that ORP4L maintained intracellular Ca2+ homeostasis. Through this mechanism, ORP4L activated nuclear factor of activated T cells (NFAT) activity and thus promoted expression of a gene cluster which supported cell proliferation. Of note, ORP4L sustained inositol-1,4,5-trisphosphate receptor 1 (IP3R1) expression at both mRNA and protein levels via Ca2+-dependent NFAT3 activation, which offered a mechanic explanation for the role of ORP4L intracellular Ca2+ homeostasis. Furthermore, ORP4L knockdown markedly inhibited tumor growth in a C33A cell xenograft mouse model. To conclude, our results reveal that ORP4L promotes cell proliferation through maintaining intracellular Ca2+ homeostasis.

Combined treatment with troglitazone and lovastatin inhibited epidermal growth factor-induced migration through the downregulation of cysteine-rich protein 61 in human anaplastic thyroid cancer cells.

Our previous studies have demonstrated that epidermal growth factor (EGF) can induce cell migration through the induction of cysteine-rich protein 61 (Cyr61) in human anaplastic thyroid cancer (ATC) cells. The aim of the present study was to determine the inhibitory effects of combined treatment with the peroxisome proliferator-activated receptor-γ (PPARγ) ligand troglitazone and the cholesterol-lowering drug lovastatin at clinically achievable concentrations on ATC cell migration. Combined treatment with 5 µM troglitazone and 1 µM lovastatin exhibited no cytotoxicity but significantly inhibited EGF-induced migration, as determined using wound healing and Boyden chamber assays. Cotreatment with troglitazone and lovastatin altered the epithelial-to-mesenchymal-transition (EMT) -related marker gene expression of the cells; specifically, E-cadherin expression increased and vimentin expression decreased. In addition, cotreatment reduced the number of filopodia, which are believed to be involved in migration, and significantly inhibited EGF-induced Cyr61 mRNA and protein expression as well as Cyr61 secretion. Moreover, the phosphorylation levels of 2 crucial signal molecules for EGF-induced Cyr61 expression, the cAMP response element-binding protein (CREB) and extracellular signal-regulated kinase (ERK), were decreased in cells cotreated with troglitazone and lovastatin. Performing a transient transfection assay revealed that the combined treatment significantly suppressed Cyr61 promoter activity. These results suggest that combined treatment with low doses of troglitazone and lovastatin effectively inhibits ATC cell migration and may serve as a novel therapeutic strategy for metastatic ATC.

Lovastatin induces apoptosis of anaplastic thyroid cancer cells via inhibition of protein geranylgeranylation and de novo protein synthesis.

Lovastatin has been used to treat hypercholesterolemia through blocking the mevalonate biosynthesis pathway. Inhibition of mevalonate synthesis may result in antiproliferation and cell apoptosis. The aim of the present study was to examine the apoptotic effect of lovastatin in human ARO cells and delineate its underlying molecular mechanism. Our results showed that lovastatin dose- and time-dependently induced apoptosis in ARO cells. Pretreatment with cycloheximide dose-dependently suppressed lovastatin-induced apoptosis, suggesting that de novo protein synthesis is required for lovastatin effect on the induction of apoptosis in ARO cells. Treatment of the cells with 50 microM lovastatin induced cytochrome c translocation from mitochondria to cytosol; increases in caspase-2, -3, and -9 activity; and poly (ADP-ribose) polymerase degradation in a time-dependent manner. However, administration of mevalonate or geranylgeraniol, but not farnesol, dose-dependently prevented lovastatin-induced poly (ADP-ribose) polymerase degradation and the occurrence of apoptosis, but treatment with geranylgeranyl transferase inhibitor, GGTI-298, which blocks the geranylgeranylation, induced an increase in the percentage of the apoptotic cells. These data suggest that geranylgeranylation is required for survival of the lovastatin-treated ARO cells. To support this notion, we demonstrate that lovastatin dose-dependently decreased the translocation of RhoA and Rac1, but not Ras, from cytosol to membrane fraction. Moreover, the lovastatin-induced translocation inhibitions in RhoA and Rac1 were prevented by mevalonate and geranylgeraniol but not farnesol. In conclusion, our data suggest that lovastatin induced apoptosis in ARO cells by inhibiting protein geranylgeranylation of the Rho family but not farnesylation of the Ras family.

Lovastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, induces apoptosis and differentiation in human anaplastic thyroid carcinoma cells.

Although only 1% of differentiated thyroid cancers transform into anaplastic thyroid cancer, this disease is always fatal. Differentiation therapy may provide a new therapeutic approach to increasing the survival rate in such patients. 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are reported to promote cellular apoptosis and differentiation in many cancer cells; these effects are unrelated to lipid reduction. Recently, we found that TNFalpha induces cytomorphological differentiation in anaplastic thyroid cancer cells and increases thyroglobulin expression; however, TNF is cytotoxic for normal human tissue. The aim of this study was to determine whether lovastatin, an HMG-CoA reductase inhibitor, could induce apoptosis and differentiation in anaplastic thyroid cancer cells. Anaplastic thyroid cancer cells were treated with lovastatin, then examined for cellular apoptosis and cytomorphological differentiation by DNA fragmentation, phosphatidylserine externalization/flow cytometry, and electron microscopy. Thyroglobulin levels in the culture medium were also measured. Our results showed that at a higher dose (50 micro M), lovastatin induced apoptosis of anaplastic thyroid cancer cells, whereas at a lower dose (25 micro M), it promoted 3-dimensional cytomorphological differentiation. It also induced increased secretion of thyroglobulin by anaplastic cancer cells. Our results show that lovastatin not only induces apoptosis, but also promotes redifferentiation in anaplastic thyroid cancer cells, and suggest that it and other HMG-CoA reductase inhibitors merit further investigation as differentiation therapy for the treatment of anaplastic thyroid cancer.

Circulating soluble Fas ligand correlates with disease activity in Graves' hyperthyroidism.

Apoptosis of thyrocytes may play an important role in the pathogenesis of autoimmune thyroiditis. Meanwhile, the Fas/Fas ligand (FasL) apoptosis pathway has received much attention in physiological homeostasis and immune regulation in various thyroid diseases, including Graves' hyperthyroidism (GD). FasL is a type II membrane protein of the tumor necrosis factor family, and induces apoptosis when it binds to Fas. Soluble FasL (sFasL) may also exert cytotoxic activity against Fas-expressing cells by producing trimerization of Fas molecule, but soluble Fas (sFas) is an apoptotic inhibitor. To determine the role of circulating sFas/sFasL in modulating disease activity of GD, we examined the circulating levels of sFas/sFasL in GD patients with various levels of anti-thyrotropin-stimulating hormone (TSH) receptor antibodies (TRAb). Serum samples were obtained from 22 consecutive untreated hyperthyroid GD patients with higher TRAb level (63.8% +/- 12.5%, group I) and 22 treated euthyroid GD patients, who were in a state of disease remission, with lower TRAb level (7.9% +/-5.9%, group II). The levels of sFas were significantly higher in group I (1.56 +/- 0.26 ng/mL) than in group II (0.76 +/- 0.26 ng/mL, P <.01). The levels of sFasL were also significantly higher in group I patients (0.153 +/- 0.018 ng/mL) than in group II patients (0.126 +/- 0.012 ng/mL, P <.01). A significant correlation was found between sFasL levels and TRAb activity in all GD patients (r = 0.69, P <.01). Because changes in sFasL levels and TRAb levels occur in parallel, increased serum sFasL in patients with GD may contribute to homeostasis in the thyroid. Serum sFasL may be considered to be a candidate marker for evaluating disease aggression or regression in GD.

Lovastatin inhibits proliferation of anaplastic thyroid cancer cells through up-regulation of p27 by interfering with the Rho/ROCK-mediated pathway.

Previously, we demonstrated that lovastatin, a HMG-CoA reductase inhibitor, induced apoptosis, differentiation, and inhibition of invasiveness of human anaplastic thyroid carcinoma cells (ATCs). Here, we further examined the effect of lovastatin on the growth of ARO cells. Lovastatin (0-20µM) concentration-dependently decreased cell number in cultured ATC and arrested the cell at the G0/G1 phase of the cell cycle. Western blot analysis revealed that lovastatin caused an increase of the protein level of p27 and cyclin-dependent kinase (CDK)4 and a decrease of the protein level of cyclin A2, cyclin D3, and phosphorylated Rb (pRb), but did not significantly change the protein levels of p21, cyclins D1 and E, and CDK2, in ARO cells. The formation of the CDK2-p27 complex was increased and the CDK2 activity was decreased in the lovastatin-treated ARO cells. Pretreatment of ARO cells with a p27, but not p21, antisense oligonucleotide prevented the lovastatin-induced G0/G1 arrest in ARO cells. The lovastatin-induced growth inhibition and translocation of RhoA and Rac1 in ARO cells were completely prevented by mevalonate and partially by geranylgeranyl pyrophosphate. Treatment of ARO cells with Y27632, an inhibitor of Rho-associated kinase, abolished the GGPP-mediated prevention of lovastatin-induced anti-proliferation and up-regulation and prolonged degradation of p27. Taken together, these data suggest that lovastatin treatment caused a reduction of Rho geranylgeranylation, which in turn increased the expression and stability of p27, and then inhibited ARO cell proliferation. These data suggest that lovastatin merits further investigation as multipotent therapy for treatment ATC.

Involvement of Ras/Raf-1/ERK actions in the magnolol-induced upregulation of p21 and cell-cycle arrest in colon cancer cells.

Previously, we showed that magnolol induces cell-cycle arrest in cultured colon and liver cancer cells through an upregulation of the p21 protein. The aim of this study was to delineate the molecular mechanism underlying this magnolol-induced increase of p21 protein. Thus our RT-PCR analysis demonstrated that the mRNA levels of p21 were increased at 1 h after magnolol treatment and sustained for at least 24 h. The p21 promoter activity was also increased by magnolol treatment. Western blot analysis demonstrated that treatment of COLO-205 cells with magnolol increased the levels of phosphorylation of extracellular signal-regulated kinase (ERK). Pretreatment of the cells with PD98059 abolished the magnolol-induced upregulation of p21 protein, suggesting the involvement of an ERK pathway in the magnolol-induced upregulation of p21 in COLO-205 cells. Ras inhibitor peptide abolished the magnolol-induced increase of phosphorylated ERK protein levels, increase of p21 protein, and decrease of thymidine incorporation. Moreover, treatment of COLO-205 with magnolol increased the phosphorylated Raf-1 protein (the Ras target molecule). Pretreatment of the cells with Raf-1 inhibitor reversed the magnolol-induced decrease in thymidine incorporation. Treatment of the cells with CaM kinase inhibitor, but not protein kinase A (PKA) inhibitor or phosphatidylinosital 3-kinase (PI3K) inhibitor, abolished the magnolol-induced activation of ERK and decrease of thymidine incorporation. Taken together, our results suggest that magnolol activates ERK phosphorylation through a Ras/Raf-1-mediated pathway. Subsequently, p21 expression is increased, and finally thymidine incorporation is decreased.

Tumor necrosis factor alpha induces three-dimensional cytomorphologic differentiation of human anaplastic thyroid carcinoma cells through activation of nuclear factor kappaB.

BACKGROUND: Anaplastic thyroid carcinoma is almost uniformly fatal. Microvilli are an important three-dimensional (3-D) cytomorphologic feature of thyrocyte differentiation, because fewer microvilli are seen in less differentiated tumors. Differentiation therapies, such as retinoic acid and somatostatin, have been tested previously in experimental models of differentiated thyroid carcinoma but not in anaplastic thyroid carcinoma. The objective of this study was to determine whether tumor necrosis factor alpha (TNF-alpha) is capable of inducing 3-D cytomorphologic differentiation of anaplastic thyroid carcinoma cells, and, if so, to investigate the mechanism involved. METHODS: Anaplastic thyroid carcinoma cells were treated with TNF-alpha and examined for evidence of cytomorphologic differentiation using electron microscopy. To study the mechanism of differentiation, immunoblotting was used to analyze inhibitory kappaB (I-kappaB) proteins and electrophoretic mobility shift assays to analyze nuclear factor kappaB (NF-kappaB) activation. The effect of NF-kappaB SN50, a NF-kappaB translocation inhibitor, on cytomorphologic changes induced in anaplastic thyroid carcinoma cells by TNF-alpha also was studied. In addition, levels of thyroglobulin and vascular endothelial growth factor (VEGF) secreted into the culture medium were measured. RESULTS: The results showed that TNF-alpha can induce activation of NF-kappaB and that the activation and translocation of NF-kappaB into the nucleus is responsible for promoting the 3-D cytomorphologic differentiation of anaplastic thyroid carcinoma cells, which was inhibited by the NF-kappaB translocation inhibitor, NF-kappaB SN50. TNF-alpha also induced increased thyroglobulin secretion and reduced VEGF secretion by anaplastic tumor cells. CONCLUSIONS: The current data suggest that TNF-alpha can induce thyrocyte differentiation in anaplastic thyroid carcinoma cells through NF-kappaB and that it merits investigation as differentiation therapy for the treatment of patients with anaplastic thyroid carcinoma. The authors also found that microvilli were useful markers for studying thyrocyte differentiation in anaplastic thyroid carcinoma cells.