• Biomedical Science Letters
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• v.25 no.2
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• pp.196-200
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• 2019

Effect of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, on the activity of nitric oxide synthase (NOS) was evaluated in human malignant keratinocytes to examine the possible correlation of retinoids with NOS activities. All-trans retinoic acid and 13-cis retinoic acid did not alter the nitric oxide (NO) production. However, in the presence of lipopolysaccharide (LPS, $1{\mu}g/mL$), they significantly increased NO release in a dose-dependent manner until 48 h at concentrations of $50{\sim}100{\mu}M$. The degree of upregulation of NO by all-trans retinoic acid and 13-cis retinoic acid increased up to 35% and 37%, respectively, compared to that by the control, which demonstrated the upregulation of LPS-inducible nitric oxide synthase (iNOS)-dependent generation of NO as well as showing a crucial link between retinoids-induced activity and NOS. Findings of this study now suggest that the upregulation of LPS-iNOS activity may be associated with modulation of retinoids-induced control of cellular developmental processes, which may produce new therapeutics of retinoids in the complexity of how NO affects human keratinocytes.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.91-91
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• 2002

We have examine the effect of all trans retinoic acid and 9-cis-retinoic acid on human breast cancer cell proliferation using SRB assay and cell cycle analysis. 1)In MCF-7 cells, in the presence of phenol red, either all trans retinoic acid or 9-cis-retinoic acid treatment showed the inhibition of the cell proliferation over control cells and also inhibit the estrogen stimulated cell proliferation when it was given together with estrogen.(omitted)

• Macromolecular Research
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• v.16 no.8
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• pp.682-685
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• 2008

The aim of this work was to develop and evaluate solid lipid nanoparticles (SLN) containing all-trans-retinoic acid (ATRA) for topical delivery. SLN composed of coconut oil and curdlan improved the suspension instability of ATRA in aqueous solution. The photodegradation of ATRA by light was reduced by incorporation in SLN. The loading efficiency of ATRA in SLN was higher than 95% (w/w). The amounts of ATRA released from SLN at $4^{\circ}C$ and at $37^{\circ}C$ were less than 15% and more than 60% (w/w) for 96 h, respectively. The ATRA-loaded SLN can be used as a potential carrier for topical delivery.

• Bulletin of the Korean Chemical Society
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• v.22 no.6
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• pp.581-586
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• 2001

The potential anticancer agents, new anthracycline analogues (2-9) have been synthesized from the glycosides daunomycin (1a) and doxorubicin (1b). Compounds 2 and 6 were prepared by nucleophilic displacement esterification of a 14-bromodauomycin(1c) with sodium or potassium salts of butyric and all trans retinoic acid, respectively. Compounds 3 and 7 were obtained from daunomycin (1a) by direct amidation with a butyric and all trans retinoic acid in the presence of EDCI and PP, respectively. Compounds 4 and 8 were obtained from doxorubicin (1b) by reaction with the corresponding acids in the same manner. Compounds 5 and 9 were prepared from doxorubicin (1b) by acylation with two equivalents of the corresponding acids under the same reaction conditions.

• Clinical and Experimental Reproductive Medicine
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• v.45 no.2
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• pp.75-81
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• 2018

Objective: Recapitulation of the spermatogenesis process in vitro is a tool for studying the biology of germ cells, and may lead to promising therapeutic strategies in the future. In this study, we attempted to transdifferentiate Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) into male germ cells using all-trans retinoic acid and Sertoli cell-conditioned medium. Methods: Human WJ-MSCs were propagated by the explant culture method, and cells at the second passage were induced with differentiation medium containing all-trans retinoic acid for 2 weeks. Putative germ cells were cultured with Sertoli cell-conditioned medium at $36^{\circ}C$ for 3 more weeks. Results: The gene expression profile was consistent with the stage-specific development of germ cells. The expression of Oct4 and Plzf (early germ cell markers) was diminished, while Stra8 (a premeiotic marker), Scp3 (a meiotic marker), and Acr and Prm1 (postmeiotic markers) were upregulated during the induction period. In morphological studies, approximately 5% of the cells were secondary spermatocytes that had completed two stages of acrosome formation (the Golgi phase and the cap phase). A few spermatid-like cells that had undergone the initial stage of tail formation were also noted. Conclusion: Human WJ-MSCs can be transdifferentiated into more advanced stages of germ cells by a simple two-step induction protocol using retinoic acid and Sertoli cell-conditioned medium.

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.139.2-140
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• 2002

• Biomedical Science Letters
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• v.23 no.3
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• pp.230-237
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• 2017

Changes in the activity of alkaline phosphatase (ALP) isoenzymes and isoforms in human serum have a major diagnostic value, therefore the regulation of ALP activities is a valuable target for therapeutic interventions. To assess the pharmacological activity of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, their tissue-specific inhibitory effect on human serum ALP activity was elucidated by chemical inhibition methods, heat-sensitive inactivation, and wheat-germ lectin precipitation test. Retinoids showed significant inhibition of the total ALP activity in human serum at a concentration of 5 mM. All-trans retinoic acid (5 mM) and 13-cis retinoic acid (5 mM) inhibited ALP activities by up to 12% and 15%, respectively, compared to that by guanidine hydrochloride (200 mM). L-phenylalanine (100 mM) and urea (30 mM) had no further inhibitory effect on ALP activities in human serum pretreated with retinoids (5 mM). Retinoids significantly inhibited ALP activities by up to 20% compared with that of tetramisole (30 mM). The ALP activities in retinoid-pretreated serum remained unchanged after the heat inactivation process. These results suggest that retinoids are inhibitors of the intestinal ALP isoenzyme. Remarkably, retinoids revealed potent inhibitory activities against ALP in wheat-germ lectin precipitant serum, indicating that they also function as inhibitors of the bone ALP isoform. The results show that retinoids inhibit the specific tissue-derived human serum ALP activities, moreover, the inhibitory effect of retinoids against bone ALP activity suggests their clinical utility as monitoring and prevention of metastasis of bone cancer.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.71-76
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• 2010

Skin irritation caused by retinol and retinoic acid results in mild erythema called as retinoid dermatitis. To develop compounds modulating the retinoid dermatitis, we tried to establish the screening method for retinoid dermatitis. At first we examined the inflammatory cytokine profile in neonatal human dermal fibroblasts which are known to be one of main site of retinoid action. As a result, interleukin-8 (IL-8) and monocytes chemoattractant protein-1 (MCP-1) were significantly produced by all trans retinoic acid (ATRA) and all trans retinol (ATROL) in dermal fibroblasts. Especially the production of MCP-1 was more than that of IL-8. The production of MCP-1 by retinoid was dose-dependently increased, continuing up to 24 hrs. After then using ethacrynic acid (ECA) known to reduce mouse ear edema induced by ATRA, we checked whether ECA suppressed the production of MCP-1. As a result, ECA effectively suppressed the production of MCP-1 in the ATRA- or ATROL-treated-fibroblasts. These results suggested that screening method effectively reflects the in vivo anti-inflammatory activity of ECA. It was reported that citral inhibited the enzyme involved in the conversion of ATROL to ATRA. We showed that citral suppressed the production of MCP-1 in ATROL-treated fibroblasts. We expect these finding might be helpful to find useful compounds modulating the side effects of retinoid or retinoid dermatitis.

• Journal of Pharmaceutical Investigation
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• v.31 no.3
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• pp.167-172
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• 2001

All-trans retinoic acid (ATRA), vitamin A acid, has been shown to exert anticancer activity in a number of types of cancers, particularly in acute promyelocytic leukaemia (APL). Due to its highly variable bioavailability and induction of its own metabolism after oral treatment, development of parenteral dosage forms are required. However, its poor aqueous solubility and chemical unstability give major drawbacks in parenteral administration. This study was undertaken to investigate a possibility to develop a parenteral formulation of ATRA by employing solid lipid nanoparticle (SLN) as a carrier. By optimizing the production parameters and the composition of SLNs, SLNs with desired mean particle size (<100 nm) as a parenteral dosage form could be produced from trimyristin (as solid lipid), Egg phosphatidylcholine and Tween 80 (as SLN stabilizer). The mean particle size of SLN formulation of ATRA was not changed during storage, suggesting its physical stability. Thermal analysis confirmed that the inner lipid core of SLNs exist at solid state. The mean particle size of ATRA-loaded SLNs was not significantly changed by the lyophilization process. ATRA could be efficiently loaded in SLNs, while maintaining its anticancer activity against HL-60, a well-known APL cell line. Furthermore, by lyophilization, ATRA loaded in SLN could be retained chemically stable during storage. Taken together, our present study demonstrates that physically and chemically stable ATRA formulation adequate for parenteral administration could be obtained by employing SLN technology.

• 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.