Rhim Ryoo

Rhim Ryoo


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
24 August 2018 in Cells
Verified
Journal Article
Open access
PDF file
SLSeulah Lee
Seulah Lee
SLSeul Lee
Seul Lee
HRHyun-Soo Roh
Hyun-Soo Roh
SSSeong-Soo Song
Seong-Soo Song
RRRhim Ryoo
Rhim Ryoo
Ki Hyun KimKi Hyun Kim
Ki Hyun Kim
Previous studies have revealed the antitumor potential of Poria cocos Wolf against a broad spectrum of cancers. However, the biological activity of P. cocos against lung cancer, which is known as the leading cause of cancer mortality worldwide, and its underlying chemical and molecular basis, remain to be investigated. We aimed to evaluate the in vitro cytotoxicity of P. cocos toward human lung adenocarcinoma cells with different p53 statuses, to identify the bioactive constituents of P. cocos, and explicate the molecular mechanisms underlying the cytotoxicity of these constituents in human lung adenocarcinoma cells. An EtOH extract of the sclerotia of P. cocos exhibited cytotoxicity toward four human lung cancer cell lines: A549, H1264, H1299, and Calu-6, regardless of their p53 status. Chemical investigation of the extract resulted in the isolation of two triterpenoids, dehydroeburicoic acid monoacetate (1) and acetyl eburicoic acid (4); a sterol, 9,11-dehydroergosterol peroxide (2); and a diterpenoid, dehydroabietic acid (3). All of the isolated compounds were cytotoxic to the lung adenocarcinoma cell lines, exhibiting IC50 values ranging from 63.6 μM to 171.0 μM at 48 h of treatment. The cytotoxicity of the extract and the isolated compounds were found to be mediated by apoptosis, and accompanied by elevated Bax expression and/or Bcl-2 phosphorylation along with caspase-3 activation. Our data demonstrate that the sclerotium of P. cocos and its four bioactive constituents (1–4) exert cytotoxicity against human lung adenocarcinoma cells, regardless of their p53 status, by inducing apoptosis associated with mitochondrial perturbation, and proposing the potential to employ P. cocos in the treatment of lung cancer.

14 March 2022 in Molecules
Verified
Journal Article
Open access
PDF file
MNMyung Woo Na
Myung Woo Na
ELEunjin Lee
Eunjin Lee
DKDong-Min Kang
Dong-Min Kang
DKDong-Min Kang
Dong-Min Kang
RRRhim Ryoo
Rhim Ryoo
Ki Hyun KimKi Hyun Kim
Ki Hyun Kim
As part of an ongoing natural product chemical research for the discovery of bioactive secondary metabolites with novel structures, wild fruiting bodies of Daedaleopsis confragosa were collected and subjected to chemical and biological analyses. We subjected the fractions derived from the methanol extract of the fruiting bodies of D. confragosa to bioactivity-guided fractionation because the methanol extract of D. confragosa showed antibacterial activity against Helicobacter pylori strain 51, according to our bioactivity screening. The n-hexane and dichloromethane fractions showed moderate to weak antibacterial activity against H. pylori strain 51, and the active fractions were analyzed for the isolation of antibacterial compounds. Liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis revealed that the n-hexane fraction contains several compounds which are absent in the other fractions, so the fraction was prioritized for further fractionation. Through chemical analysis of the active n-hexane and dichloromethane fractions, we isolated five ergosterol derivatives (1–5), and their chemical structures were determined to be demethylincisterol A3 (1), (20S,22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol (2), (24S)-ergosta-7-ene-3β,5α,6β-triol (3), 5α,6α-epoxy-(22E,24R)-ergosta-7,22-dien-3β-ol (4), and 5α,6α-epoxy-(24R)-ergosta-7-en-3β-ol (5) by NMR spectroscopic analysis. This is the first report on the presence of ergosterol derivatives (1–5) in D. confragosa. Compound 1 showed the most potent anti-H. pylori activity with 33.9% inhibition, rendering it more potent than quercetin, a positive control. Compound 3 showed inhibitory activity comparable to that of quercetin. Distribution analysis of compound 1 revealed a wide presence of compound 1 in the kingdom Fungi. These findings indicate that demethylincisterol A3 (1) is a natural antibiotic that may be used in the development of novel antibiotics against H. pylori.

23 December 2019 in Genes
Verified
Journal Article
Open access
PDF file
SYSang Ah Yi
Sang Ah Yi
KNKi Hong Nam
Ki Hong Nam
SKSil Kim
Sil Kim
HSHae Min So
Hae Min So
RRRhim Ryoo
Rhim Ryoo
JLJaecheol Lee
Jaecheol Lee
Vulpinic acid, a naturally occurring methyl ester of pulvinic acid, has been reported to exert anti-fungal, anti-cancer, and anti-oxidative effects. However, its metabolic action has not been implicated yet. Here, we show that vulpinic acid derived from a mushroom, Pulveroboletus ravenelii controls the cell fate of mesenchymal stem cells and preadipocytes by inducing the acetylation of histone H3 and α-tubulin, respectively. The treatment of 10T1/2 mesenchymal stem cells with vulpinic acid increased the expression of Wnt6, Wnt10a, and Wnt10b, which led to osteogenesis inhibiting the adipogenic lineage commitment, through the upregulation of H3 acetylation. By contrast, treatment with vulpinic acid promoted the terminal differentiation of 3T3-L1 preadipocytes into mature adipocytes. In this process, the increase in acetylated tubulin was accompanied, while acetylated H3 was not altered. As excessive generation of adipocytes occurs, the accumulation of lipid drops was not concentrated, but dispersed into a number of adipocytes. Consistently, the expressions of lipolytic genes were upregulated and inflammatory factors were downregulated in adipocytes exposed to vulpinic acid during adipogenesis. These findings reveal the multiple actions of vulpinic acid in two stages of differentiation, promoting the osteogenesis of mesenchymal stem cells and decreasing hypertrophic adipocytes, which can provide experimental evidence for the novel metabolic advantages of vulpinic acid.

1 November 2022 in Genomics
Verified
Journal Article
Open access
JKJaewook Kim
Jaewook Kim
MPMi-Jeong Park
Mi-Jeong Park
DSDonghwan Shim
Donghwan Shim
RRRhim Ryoo
Rhim Ryoo
Omphalotus guepiniiformis, a bioluminescent mushroom species, is a source of the potentially valuable anticancer chemical. To provide genome information, we de novo assembled the high-quality O. guepiniiformis genome using two Next-Generation sequencing techniques, PacBio and Illumina sequencing. Our draft O. guepiniiformis genome comprises 42.5 Mbp of sequence with only 80 contigs and an N50 sequence length of over 1 Mbp. There were 15,554 predicted coding genes, and 7693 genes were functionally annotated with Gene Ontology terms. We performed a genomic study focusing on mushroom bioluminescent pathway cluster genes by comparing 17 luminescent and 23 non-luminescent Agaricales species belonging to 23 genera. Synteny analysis of genomic regions near the luminescent pathway cluster genes inferred that the Omphalotus lineage was genus-specific. In summary, our de novo assembled O. guepiniiformis genome provides significant biological insights into this organism, including the evolution of the luciferase gene block, and forms the basis for future analyses.

13 June 2017 in Mycological Progress
Verified
Journal Article
Closed access
PDF file
VAVladimír Antonín
Vladimír Antonín
VHValérie Hofstetter
Valérie Hofstetter
RRRhim Ryoo
Rhim Ryoo
KKKang-Hyeon Ka
Kang-Hyeon Ka
BBBart Buyck
Bart Buyck

10 July 2023 in Nutrients
Verified
Journal Article
Open access
PDF file
DLDahae Lee
Dahae Lee
SLSeulah Lee
Seulah Lee
YJYoon Seo Jang
Yoon Seo Jang
RRRhim Ryoo
Rhim Ryoo
Jung Hyun KimJung Hyun Kim
Jung Hyun Kim
Ki Hyun KimKi Hyun Kim
Ki Hyun Kim
Breast cancer ranks among the most prevalent malignancies affecting women worldwide, and apoptosis-targeting drugs are attractive candidates for the treatment of cancer. In the current study, we investigated the in vitro cytotoxicity of the mushroom Calvatia nipponica in human breast cancer cells (MDA-MB-231), identified potential antitumor compounds through bioactivity-guided isolation, and elucidated the antitumor, pro-apoptotic molecular mechanisms of the identified bioactive compounds. C. nipponica is edible when young, and it has been used as a food source as well as a traditional medicine in wound dressings. However, only a limited number of studies have reported its chemical composition and biological activities. In the screening test, the methanol extract of C. nipponica fruiting bodies exhibited cytotoxicity against MDA-MB-231 cells. Bioactivity-guided fractionation of the methanol (MeOH) extract and chemical investigation of the active fractions resulted in the isolation of fourteen compounds (1–14), including six alkaloids (1–3, 5, 7, and 8), two phenolic compounds (4 and 6), one fatty acid (9), and five steroids (10–14). The structures of the isolated compounds were determined using NMR spectroscopic methods, liquid chromatography–mass spectrometry, and comparison of data with previously reported values. The isolated compounds (1–14) were tested for cytotoxicity against MDA-MB-231 cells, where compound 1, i.e., N,N-dimethyl-anthranilic acid, exhibited the most significant cytotoxicity against MDA-MB-231 cells, with an IC50 value of 90.28 ± 4.23 μM and apoptotic cell death of 56.01% ± 2.64% at 100 μM. Treatment with compound 1 resulted in an upregulation of protein levels, including cleaved caspase-8, cleaved poly (ADP-ribose) polymerase, Bcl-2-associated X protein (Bax), cleaved caspase-3, cleaved caspase-9, Bad, and Cytochrome c, but decreased the levels of B-cell lymphoma 2 (Bcl-2). Overall, these results indicate that N,N-dimethyl-anthranilic acid (1) may have anti-breast cancer activity and is probably involved in the induction of apoptosis mediated by extrinsic and intrinsic signaling pathways.