• BMB Reports
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• 제43권9호
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• pp.599-603
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• 2010

Troglitazone is an anti-diabetic agent that improves hyperglycemia by reducing peripheral insulin resistance in type II diabetic patients. Troglitazone has been shown to cause growth inhibition of various normal and cancerous cells. However, the molecular mechanism by which troglitazone affects the growth of these cancer cells remains unclear. Here, we report that troglitazone treatment of Hep 3B human hepatocellular carcinoma cells resulted in dose-dependent growth inhibition. Analysis of cell cycle distribution by flow cytometry showed that the number of apoptotic cells was increased in a dose-dependent manner in response to troglitazone treatment. cDNA microarray analysis showed a number of differentially expressed genes in response to troglitazone. Among the upregulated genes, hypoxia-inducible factor 1 (HIF-1)-responsive RTP801 was induced in a dose-dependent manner. We also observed HIF-1 accumulation by immnocytochemistry after troglitazone treatment. These results strongly suggest that RTP801 might be involved in troglitazone-induced apoptosis in Hep 3B cells.

• 대한의생명과학회지
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• 제12권4호
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• pp.319-327
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• 2006

This study aimed to determine whether troglitazone stimulates genes related to fatty acid ${\beta}$-oxidation, leading to modulation of white adipose tissue (WAT) metabolism in high fat diet-fed mice. Female C57BL/6J mice were randomly divided into two groups (n=10/group). After they received either a high fat diet or the same high fat diet supplemented with troglitazone for 4 weeks, the effects of troglitazone on gene expression and physiology of WAT were measured using Northern, histological and serological analyses. Administration of troglitazone induced the expression of genes involved in mitochondrial and peroxisomal fatty acid ${\beta}$-oxidation in mesenteric WAT. Troglitazone also significantly increased uncoupling protein 2 mRNA levels. The changes in WAT gene expression were accompanied by reductions in circulating levels of free fatty acids and triglycerides as well as glucose and insulin. Histological studies showed that troglitazone treatment decreased the average size of adipocytes in mesenteric WAT. These results suggest that troglitazone-stimulated WAT expression of genes associated with fatty acid ${\beta}$-oxidation regulates WAT metabolism of high fat diet-fed mice, contributing to improvement of insulin sensitivity.

• 대한의생명과학회지
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• 제12권2호
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• pp.65-72
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• 2006

Thiazolidinediones (TZDs) are widely used antidiabetic drugs that activate the nuclear peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$, and thereby improve the metabolic abnormalities linking hypertriglyceridemia to diabetes, hyperglycemia, insulin resistance, and cardiovascular disease. To determine whether the $PPAR{\gamma}$ ligand troglitazone regulates lipid metabolism with sexual dimorphism, we examined the effects of troglitazone on circulating lipids, body weight and the expression of hepatic genes responsible for lipid metabolism in both sexes of C57BL/6J mice. Compared to mice fed a low fat control diet, both sexes of mice fed a troglitazone-treated low fat diet for 14 weeks did not exhibit changes in body weight gain, serum total cholesterol, HDL-cholesterol and LDL-cholesterol levels. However, serum triglycerides were significantly reduced in both sexes of mice, although these effects were more pronounced among males. Furthermore, troglitazone regulated the expression of hepatic genes critical for lipid and lipoprotein metabolism, the magnitudes of which were much higher in males compared to females, as evidenced by results for increased acyl-CoA oxidase and decreased apolipoprotein C-III mRMA levels. These results suggest that $PPAR{\gamma}$ activator troglitazone may exert sexually dimorphic control of serum triglycerides in part through the differential activation of $PPAR{\gamma}$ in liver between male and female mice.

• 대한의생명과학회지
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• 제14권3호
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• pp.139-146
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• 2008

The peroxisome proliferator-activated receptor ${\gamma}$ $(PPAR{\gamma})$ plays a central role in adipogenesis and lipid storage. The $(PPAR{\gamma})$ ligands, thiazolidinediones (TZDs), enhance in vitro adipogenesis in several cell types, but the role of the TZDs on in vivo adipogenesis is still poorly understood. To investigate how $PPAR{\gamma}$ ligand troglitazone regulates adipogenesis in female mice, we examined the effects of the troglitazone on adipose tissue mass, morphological changes of adipocytes, and the expression of $PPAR{\gamma}$ target and adipocyte-specific genes in low fat diet-fed female C57BL/6 mice. Administration of troglitazone for 13 weeks did not change body and total white adipose tissue weights compared with control mice. Troglitazone treatment also did not cause a significant decrease in the average size of adipocytes in parametrial adipose tissue although it is reported to increase the number of small adipocytes in male animals. Troglitazone did not affect the mRNA expression of $PPAR{\gamma}$ and its target genes as well as adipocyte-specific genes in parametrial adipose tissue. These results suggest that $PPAR{\gamma}$ does not seem to be associated with adipogenesis in females with functioning ovaries and that its inability to induce adipogenesis may be due to sex-related factors.

• 대한골관절종양학회지
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• 제17권1호
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• pp.23-29
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• 2011

목적: 본 연구에서는 골육종 세포내 PTEN 발현정도가 세포 성장과 트로글리타존에 대한 반응도에 미치는 영향에 대해 알아보고자 하였다. 대상 및 방법: 웨스턴 블롯 분석을 통해 트로글리타존 처리 후 PTEN 발현 정도를 관찰하였고, WST를 통해 세포 증식정도를 측정하였다. 야생형 PTEN 및 돌연변이형 PTEN 발현시키는 플라스미드 DNA를 트랜스펙션하여 PTEN 발현 정도를 측정하였다. 결과: 사람골육종 세포주 U-2OS는 트로글리타존 처리 농도 및 시간에 비례하여 증식 억제를 보였고, 세포내 PTEN 발현 정도는 트로글리타존 처리 농도에 비례하여 증가하였다. 트로글리타존을 이용하여 U-2OS세포 내 PTEN 발현을 증가시키면 세포 성장 억제와 세포사 유도가 나타났다. 또한 플라스미드 트랜스펙션에 의한 PTEN 과발현은 트로글리타존의 세포증식 억제 효과를 증가 시키며 돌연변이형 PTEN을 트랜스펙션 시키는 경우 세포증식효과는 관찰되지 않았다. 결론: 골육종 세포내 PTEN 과발현이 트로글리타존에 의한 골육종 세포의 증식 억제 및 세포사 유도와 관련 되어있음을 알 수 있으며, 세포내에 PTEN이 과발현 된 상태에서 트로글리타존의 효과가 증가됨을 알 수 있었다.

• Biomolecules & Therapeutics
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• 제18권1호
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• pp.16-23
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• 2010

Adipocyte differentiation in human bone marrow mesenchymal stem cells (hBM-MSCs) is not as efficient as that in murine pre-adipocytes when induced by adipogenic agents including insulin, dexamethasone, and 3-isobutyl-1-methylxanthine (IDX condition). Therefore, the promotion of adipocyte differentiation in hBM-MSCs has been used as a cell culture model to evaluate insulin sensitivity for anti-diabetic drugs. In hBM-MSCs, $PPAR{\gamma}$ agonists or sulfonylurea anti-diabetic drugs have been added to IDX conditions to promote adipocyte differentiation. Here we show that troglitazone, a peroxisome proliferator-activated receptor-gamma ($PPAR{\gamma}$) agonist, significantly reduced the levels of anti-adipogenic $PGE_2$ in IDX-conditioned hBM-MSC culture supernatants when compared to $PGE_2$ levels in the absence of $PPAR{\gamma}$ agonist. However, there was no difference in the mRNA levels of cyclooxygenases (COXs) and the activities of COXs and prostaglandin synthases during adipocyte differentiation in hBM-MSCs with or without troglitazone. In hBM-MSCs, troglitazone significantly increased the mRNA level of 15-hydroxyprostaglandin dehydrogenase (HPGD) which can act to decrease $PGE_2$ levels in culture. These results suggest that the role of $PPAR{\gamma}$ activation in promoting adipocyte differentiation in hBM-MSCs is to reduce anti-adipogenic $PGE_2$ levels through the up-regulation of HPGD expression.

• 대한의생명과학회지
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• 제10권2호
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• pp.137-142
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• 2004

The peroxisome proliferator-activated receptor $\gamma$ (PPAR${\gamma}$) is the molecular target for a class of drugs, the antidiabetic thiazolidnediones (TZDs). The heterodimer of PPAR${\gamma}$ with retinoid X receptor (RXR) plays a central role in the regulation of adipogenesis and insulin sensitization. We synthesized two chemicals, DANA87 and DANA88, sharing structural characteristics with TZDs. Given this structural similarity, it was hypothesized that DANA87 and DANA88 may act as PPAR$\gamma$ ligands. In transient transfection assays, DANA87 and DANA88 caused slight increases in the endogenous expression of a luciferase reporter gene containing the PPAR responsive element in 3T3-L1 preadipocytes. However, DANA87 and DANA88 significantly inhibited troglitazone-induced reporter gene activation when cells were treated with a combination of DANA87 or DANA 88 and troglitazone, one of the TZDs that activate PPAR$\gamma$. These results suggest that DANA87 and DANA88 are not only weak agonists of PPAR${\gamma}$ transactivation, but also competitively antagonize troglitazone-induced PPAR$\gamma$ reporter activity.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2313-2318
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• 2014

Peroxisome proliferator-activated receptor gamma (PPAR-${\gamma}$), a ligand-dependent nuclear transcription factor, has been found to widely exist in tumor tissues and plays an important role in affecting tumor cell growth. In this study, we investigated the effect of PPAR-${\gamma}$ on aspects of the cervical cancer malignant phenotype, such as cell proliferation and apoptosis. Cell growth assay, Western blotting, Annexin V and flow cytometry analysis consistently showed that treatment with troglitazone (TGZ, a PPAR-${\gamma}$ agonist) led to dose-dependent inhibition of cervical cancer cell growth through apoptosis, whereas T0070907 (another PPAR-${\gamma}$ antagonist) had no effect on Hela cell proliferation and apoptosis. Furthermore, we also detected the protein expression of p53, p21 and Mdm2 to explain the underlying mechanism of PPAR-${\gamma}$ on cellular apoptosis. Our work, finally, demonstrated the existence of the TGZ-PPAR-${\gamma}$-p53 signaling pathway to be a critical regulator of cell apoptosis. These results suggested that PPAR-${\gamma}$ may be a potential therapeutic target for cervical cancer.

• International Journal of Oral Biology
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• 제41권3호
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• pp.113-118
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• 2016

An FDA approved drug for the treatment of type II diabetes, Troglitazone (TRO), a peroxisome proliferator-activated receptor gamma agonist, is withdrawn due to severe idiosyncratic hepatotoxicity. In the search for new applications of TRO, we investigated the cellular effects of TRO on YD15 tongue carcinoma cells. TRO suppressed the growth of YD15 cells in the MTT assay. The inhibition of cell growth was accompanied by the induction of cell cycle arrest at $G_0/G_1$ and apoptosis, which are confirmed by flow cytometry and western blotting. TRO also suppressed the expression of cell cycle proteins such as cyclin D1, cdk2, cdk4, cyclin B1, cdk1(or cdc2), cyclin E1 and cyclin A. The inhibition of cell cycle proteins was coincident with the up-regulation of $p21^{CIP1/WAF1}$ and $p27^{KIP1}$. In addition, TRO induces the activation of caspase-3 and caspase-7, as well as the cleavage of PARP. Further, TRO suppressed the expressions of Bcl-2 without affecting the expressions of Bad and Bax. Overall, our data supports that TRO induces cell cycle arrest and apoptosis on YD15 cells.

• Radiation Oncology Journal
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• 제28권2호
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• pp.91-98
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• 2010

목 적: Troglitazone (TRO)은 PPAR-$\gamma$ 작동제로서 온열감수성의 결정에 중요한 요인인 heat shock protein (HSP) 70의 합성을 저해하고 superoxide dismutase (SOD)와 카타라제를 증가시키는 것으로 알려져 있다. 이에 자궁경부암 세포를 대상으로 TRO가 온열감수성에 미치는 영향을 연구하였다. 대상 및 방법: HeLa 세포를 $5{\mu}M$ TRO로 24시간 처치한 후 $42^{\circ}C$에서 1시간 동안 온열처리를 시행하였다. 세포 생존 분획은 clonogenic assay로 측정하였다. 단백질 발현의 변화는 Western blot으로 분석하였다. SOD와 카타라제의 활성도를 측정하였으며, reactive oxygen species (ROS) 는 2',7'-dichlorofluorescin diacetate와 dihydroethidium 를 사용하여 측정하였다. 결 과: 온열처리에 의해 감소된 생존분획이 TRO 전처치에 의해 증가하였다. 온열처리에의해 HSP 70의 발현은 증가하였으나 TRO 전 처치에 의해 감소되지는 않았다. SOD와 카타라제의 활성도가 각각 1.2배, 1.3배 증가하였다. 온열처리에 의해 ROS가 증가하였으며, 증가된 ROS는 TRO 전 처치에 의해 감소하였다. 결 론: TRO는 SOD와 카타라제의 활성도를 증가시키며 이는 온열에 의한 ROS를 감소시켜 결과적으로 온열감수성을 저하시킨다.