• YAKHAK HOEJI
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• v.40 no.6
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• pp.690-696
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• 1996

It has been known that many kinds of cancer are caused by continued proliferation or abnormal differentiation. Thus, recent approaches to anticancer therapy have been focused on developing drugs that induce differentiation of cancer cells to normal cells. A typical differentiation agent, all trans-retinoic acid, is unsuitable for anticancer drug because all trans-retinoic acid produces unfavorable side effects and cytotoxicity in normal cells. Therefore, we have screened some new differentiation-inducing compounds obtained from marine organisms using F9 teratocarcinoma stem cells as a model system. We observed that fatty acid. glycolipid, saponin, sphingosine and sterol compounds of marine organisms had differentiation-inducing activity in F9 cells, were determined by morphological changes and Northern blot analysis. The expression of differentiation marker genes, such as laminin B1, type IV collagen and retinoic acid receptor beta were induced by treatment with those compounds.

• Journal of Ginseng Research
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• v.27 no.3
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• pp.93-97
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• 2003

Alternative or complementary medicine plays an important role in health care system. Ginseng, being one of the most popular oriental herbs, is believed to contain various steroid hormone activity. Ginseng has been demonstrated pharmacological effect in the cardiovascular, endocrine, central nervous, and immune system. Our objective was to study that total saponin might mediate some of their actions by binding to the steroid hormone receptor, as they share many of the actions of steroid hormone in various physiological system. Using total saponin from Panax Ginseng, we have studied the possibility of total saponin being a potential estrogen receptor, androgen receptor, and retinoic acid receptor ligand. Total saponin activated the transcription of both the estrogen and androgen responsive luciferase reporter plasmids at a concentration of 100$\mu\textrm{g}$/ml in COS cells transiently transfected with the corresponding receptor and hormone responsive receptor plasmids. And total saponin caused a concentration-dependent stimulation of estrogen receptor. Total saponin increased the expression of estrogen responsive c-fos proto-oncogene at the protein level in MCF7 cells at 24 h treatment as examined by Western analysis. The c-fos induction was used as a specific marker of estrogen responsiveness. This activation was inhibited by the specific estrogen receptor antagonist, ICI 182,780. However, total saponin failed to activate the retinoic acid receptor in COS cells transiently transfected with the corresponding receptor and retinoic acid responsive reporter plasmids. These results show that total saponin is capable of activating estrogen and androgen receptors.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.115-120
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• 2012

Retinoic acid plays an important role in the regulation of cell growth and differentiation. In our present study, we evaluated the effects of all-trans retinoic acid (RA) on cell proliferation and on the cell cycle regulation of human gingival fibroblasts (HGFs). Cell proliferation was assessed using the MTT assay. Cell cycle analysis was performed by flow cytometry, and cell cycle regulatory proteins were determined by western blot. Cell proliferation was increased in the presence of a 0.1 nM to 1 ${\mu}M$ RA dose range, and maximal growth stimulation was observed in cells exposed to 1 nM of RA. Exposure of HGFs to 1 nM of RA resulted in an augmented cell cycle progression. To elucidate the molecular mechanisms underlying cell cycle regulation by RA, we measured the intracellular levels of major cell cycle regulatory proteins. The levels of cyclin E and cyclin-dependent kinase (CDK) 2 were found to be increased in HGFs following 1 nM of RA treatment. However, the levels of cyclin D, CDK 4, and CDK 6 were unchanged under these conditions. Also after exposure to 1 nM of RA, the protein levels of $p21^{WAF1/CIP1}$ and $p16^{INK4A}$ were decreased in HGFs compared with the control group, but the levels of p53 and pRb were similar between treated and untreated cells. These results suggest that RA increases cell proliferation and cell cycle progression in HGFs via increased cellular levels of cyclin E and CDK 2, and decreased cellular levels of $p21^{WAF1/CIP1}$ and $p16^{INK4A}$.

• BMB Reports
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• v.33 no.5
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• pp.407-411
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• 2000

The effects of heat shock, or all-trans retinoic acid, on the expression of the C-reactive protein mRNA in the HT-29 human colon carcinoma cells, as well as the functional role of the C-reactive protein as a molecular chaperone, were studied. The expression level of the C-reactive protein mRNA in the HT-29 cells was increased time-dependently when exposed to heat-shock, and dose-dependently when treated with all-trans retinoic acid. The activities of transglutaminase C and K in the HT-29 cells were significantly increased when treated with all-trans retinoic acid. The C-reactive protein prevented thermal aggregation of the citrate synthase and stabilized the target enzyme, citrate synthase. The C-reactive protein promoted functional refolding of the urea-denatured citrate synthase up to 40-70%. These results suggest that the C-reactive protein, which is induced in human colon carcinoma cells, when heated or treated with all-trans retinoic acid has in a part functional activity of the molecular chaperone.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1317-1321
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• 2004

The differentiation of the sebaceous gland is remarkably species-specific and sebocytes may play crucial parts in the pathophysiologic processes and disorders of pilosebaceous unit SZ95 cell is an immortalized human sebaceous gland cell line that shows characteristics of normal human sebocytes, In this study, we investigated the effect of testosterone and the anti-androgenic effect of 13-cis-retinoic acid (13-cis-RA) on lipid synthesis in SZ95 cells. Cytoplasmic lipid droplets were shown by Oil-red staining. The majority of the SZ95 cells positively labeled with Oil-red dye, while HaCaT cells negatively labeled with Oil red dye. Total lipid level of SZ96 cells is higher 4 times than that of HaCat cells. Testosterone markedly increased 2 times lipid synthesis of SZ95 cells in compared with control. 13-cis-RA significantly inhibited lipid synthesis and cell proliferation in SZ95 cells. Combined treatment with testosterone and 13-cis-RA resulted in a lower total lipid levels than that with androgen alone. In conclusion, SZ95 cells well resembled the morphologic and functional characteritics of normal human sebocytes. This in vitro model could provide a valuable tool for the study of sebocytes with a key role in pathophysiology and differentiation of sebaceous glands.

• Molecules and Cells
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• v.39 no.12
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• pp.877-887
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• 2016

Tazarotene-induced gene 1 (TIG1) is a retinoic acid-inducible protein that is considered a putative tumor suppressor. The expression of TIG1 is decreased in malignant prostate carcinoma or poorly differentiated colorectal adenocarcinoma, but TIG1 is present in benign or well-differentiated tumors. Ectopic TIG1 expression led to suppression of growth in cancer cells. However, the function of TIG1 in cell differentiation is still unknown. Using a yeast two-hybrid system, we found that transmembrane protein 192 (TMEM192) interacted with TIG1. We also found that both TIG1A and TIG1B isoforms interacted and co-localized with TMEM192 in HtTA cervical cancer cells. The expression of TIG1 induced the expression of autophagy-related proteins, including Beclin-1 and LC-3B. The silencing of TMEM192 reduced the TIG1-mediated upregulation of autophagic activity. Furthermore, silencing of either TIG1 or TMEM192 led to alleviation of the upregulation of autophagy induced by all-trans retinoic acid. Our results demonstrate that the expression of TIG1 leads to cell autophagy through TMEM192. Our study also suggests that TIG1 and TMEM192 play an important role in the all-trans retinoic acid-mediated upregulation of autophagic activity.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.211-218
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• 2010

Purpose: All-trans retinoic acid (ATRA) has anti proliferative effects against brain tumor cells. Recently, ATRA has been reported to induce catalase. We investigated whether catalase induction by ATRA is associated with its anti proliferative effects. Materials and Methods: 36B10 cells were exposed to 0~50${\mu}M$ ATRA for 24 or 48 hours and mRNA, protein, and activity of catalase were measured. Reactive oxygen species (ROS) were measured using 2',7'-dichlorofluorescin diacetate. A clonogenic assay was used to confirm the cytotoxic effect. Results: The mRNA, protein, and activity of catalase were found to increase in a concentration- and incubationtime-dependent manner. The increase in catalase activity induced by ATRA was decreased by the addition of 3-amino-1,2,4-triazole (ATZ). ROS was also increased with ATRA and decreased by the addition of ATZ. The decrease in cell survival induced by ATRA was partly rescued by ATZ. Conclusion: Catalase induction by ATRA is involved in ROS overproduction and thus inhibits the proliferation of 36B10 cells.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1397-1410
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• 2021

The present study was designed to determine the influence of all-trans retinoic acid (ATRA) on adipogenesis-related gene regulation in bovine intramuscular (IM) and subcutaneous (SC) adipose cells during differentiation. Bovine IM and SC adipocytes were isolated from three 19-mo-old, crossbred steers. Adipogenic differentiation was induced upon cultured IM and SC preadipocytes with various doses (0, 0.001, 0.01, 0.1, 1 µM) of ATRA. After 96 h of incubation, cells were harvested and used to measure the gene expression of CCAAT/Enhancer binding protein β (C/EBPβ), peroxisome proliferator-activated receptor (PPAR) γ, glucose transporter 4 (GLUT4), stearoyl CoA desaturase (SCD), and Smad transcription factor 3 (Smad3) relative to the quantity of ribosomal protein subunit 9 (RPS 9). Retinoic acid receptor (RAR) antagonist also tested to identify the effect of ATRA on PPARγ -RAR related gene expression in IM cells. The addition of ATRA to bovine IM decreased (p < 0.05) expression of PPARγ. The expression of PPARγ was also tended to be downregulated (p < 0.1) in high levels (10 µM) of ATRA treatment in SC cells. The treatment of RAR antagonist increased the expression of PPARγ in IM cells. Expression of C/EBPβ decreased (p < 0.05) in SC, but no change was observed in IM (p > 0.05). Increasing levels of ATRA may block adipogenic differentiation via transcriptional regulation of PPARγ. The efficacy of ATRA treatment in adipose cells may vary depending on the location.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.230-243
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• 2023

Objective: High temperatures can trigger cellular oxidative stress and disrupt spermatogenesis, potentially leading to male infertility. We investigated the effects of retinoic acid (RA), chitosan nanoparticles (CHNPs), and retinoic acid loaded with chitosan nanoparticles (RACHNPs) on spermatogenesis in mice induced by scrotal hyperthermia (Hyp). Methods: Thirty mice (weighing 25 to 30 g) were divided into five experimental groups of six mice each. The groups were as follows: control, Hyp induced by a water bath (43 ℃C for 30 minutes/day for 5 weeks), Hyp+RA (2 mg/kg/day), Hyp+CHNPs (2 mg/kg/72 hours), and Hyp+RACHNPs (4 mg/kg/72 hours). The mice were treated for 35 days. After the experimental treatments, the animals were euthanized. Sperm samples were collected for analysis of sperm parameters, and blood serum was isolated for testosterone measurement. Testis samples were also collected for histopathology assessment, reactive oxygen species (ROS) evaluation, and RNA extraction, which was done to compare the expression levels of the bax, bcl2, p53, Fas, and FasL genes among groups. Additionally, immunohistochemical staining was performed. Results: Treatment with RACHNPs significantly increased stereological parameters such as testicular volume, seminiferous tubule length, and testicular cell count. Additionally, it increased testosterone concentration and improved sperm parameters. We observed significant decreases in ROS production and caspase-3 immunostaining in the RACHNP group. Moreover, the expression levels of bax, p53, Fas, and FasL significantly decreased in the groups treated with RACHNPs and RA. Conclusion: RACHNPs can be considered a potent antioxidative and antiapoptotic agent for therapeutic strategies in reproductive and regenerative medicine.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.134-144
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• 2019

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased with the incidence of obesity; however, the underlying mechanisms are unknown. In this study, high-resolution metabolomics (HRM) along with transcriptomics were applied on animal models to draw a mechanistic insight of NAFLD. Wild type (WT) and catalase knockout (CKO) mice were fed with normal fat diet (NFD) or high fat diet (HFD) to identify the changes in metabolic and transcriptomic profiles caused by catalase gene deletion in correspondence with HFD. Integrated omics analysis revealed that cholic acid and $3{\beta}$, $7{\alpha}$-dihydroxy-5-cholestenoate along with cyp7b1 gene involved in primary bile acid biosynthesis were strongly affected by HFD. The analysis also showed that CKO significantly changed all-trans-5,6-epoxy-retinoic acid or all-trans-4-hydroxy-retinoic acid and all-trans-4-oxo-retinoic acid along with cyp3a41b gene in retinol metabolism, and ${\alpha}/{\gamma}$-linolenic acid, eicosapentaenoic acid and thromboxane A2 along with ptgs1 and tbxas1 genes in linolenic acid metabolism. Our results suggest that dysregulated primary bile acid biosynthesis may contribute to liver steatohepatitis, while up-regulated retinol metabolism and linolenic acid metabolism may have contributed to oxidative stress and inflammatory phenomena in our NAFLD model created using CKO mice fed with HFD.