• 제목/요약/키워드: Biomedicine

검색결과 301건 처리시간 0.034초

Combinatorial Antitumor Activity of Oxaliplatin with Epigenetic Modifying Agents, 5-Aza-CdR and FK228, in Human Gastric Cancer Cells

  • Park, Jong Kook;Seo, Jung Seon;Lee, Suk Kyeong;Chan, Kenneth K;Kuh, Hyo-Jeong
    • Biomolecules & Therapeutics
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    • 제26권6호
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    • pp.591-598
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    • 2018
  • Epigenetic silencing is considered to be a major mechanism for loss of activity in tumor suppressors. Reversal of epigenetic silencing by using inhibitors of DNA methyltransferase (DNMT) or histone deacetylases (HDACs) such as 5-Aza-CdR and FK228 has shown to enhance cytotoxic activities of several anticancer agents. This study aims to assess the combinatorial effects of genesilencing reversal agents (5-Aza-CdR and FK228) and oxaliplatin in gastric cancer cells, i.e., Epstein-Barr virus (EBV)-negative SNU-638 and EBV-positive SNU-719 cells. The doublet combinatorial treatment of 5-Aza-CdR and FK228 exhibited synergistic effects in both cell lines, and this was further corroborated by Zta expression induction in SNU-719 cells. Three drug combinations as 5-Aza-CdR/FK228 followed by oxaliplatin, however, resulted in antagonistic effects in both cell lines. Simultaneous treatment with FK228 and oxaliplatin induced synergistic and additive effects in SNU-638 and SNU-719 cells, respectively. Three drug combinations as 5-Aza-CdR prior to FK228/oxaliplatin, however, again resulted in antagonistic effects in both cell lines. This work demonstrated that efficacy of doublet synergistic combination using DNMT or HDACs inhibitors can be compromised by adding the third drug in pre- or post-treatment approach in gastric cancer cells. This implies that the development of clinical trial protocols for triplet combinations using gene-silencing reversal agents should be carefully evaluated in light of their potential antagonistic effects.

Effects of R. Glutinosa and E. Senticosus on Postmenopausal Osteoporosis

  • Oh, Soo-Yeon;Aryal, Dipendra Kumar;Kim, Yoon-Gyoon;Kim, Hyung-Gun
    • The Korean Journal of Physiology and Pharmacology
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    • 제11권3호
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    • pp.121-127
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    • 2007
  • In this study, we investigated the therapeutic effects of a novel formulation of low-dose calcium and vitamin $D_3$ blended with Rehmannia glutinosa Libosch and Eleutherococcus senticosus Max (RE+), in postmenopausal women. The controls were given either a placebo or high dose calcium and vitamin $D_3$ (Ca + D). Bone mineral density (BMD) in the L2-3 lumber spines and femur regions was assessed, and serum osteocalcin, bone-specific alkaline phosphatase (BALP), and cross-linked N-telopeptide of type I collagen (NTx) were used as markers of osteoblast and osteoclast activity. Furthermore, all variables were measured before and after 6 and 12 months of treatment. The osteocalcin level was higher in the RE+ group, and BALP was almost the same in all groups. Serum NTx was significantly decreased in the RE+ group after 12 months (p<0.05). The NTx in the Ca + D and placebo groups showed no significant change. The decrease of femur BMD was further demonstrated in the placebo group, but significantly increased in the RE+ group after 6 and 12 months of treatment (p<0.05). There were significant differences in the percent changes of femur BMD between the placebo and RE+ groups (p<0.01) and Ca+D and RE+ groups (p<0.05). The decrease of spine BMD in the placebo group was inhibited both in the Ca + D and RE+ groups, however, there was significant difference only between the placebo and RE+ groups (p<0.05). These findings suggest that continuous oral therapy of the RE+ formulation reduces rapidly decreasing bone mineral density in postmenopausal women more effectively than high doses of calcium and vitamin $D_3$ alone by inhibiting osteoclastic activity. Therefore, it seems that the RE+ has its own antiosteoporotic effects. We suggest larger clinical studies to determine the most efficacious dosage and benefits of this novel treatment.

Sex hormones alter the response of Toll-like receptor 3 to its specific ligand in fallopian tube epithelial cells

  • Zandieh, Zahra;Amjadi, Fatemehsadat;Vakilian, Haghighat;Aflatoonian, Khashayar;Amirchaghmaghi, Elham;Fazeli, Alireza;Aflatoonian, Reza
    • Clinical and Experimental Reproductive Medicine
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    • 제45권4호
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    • pp.154-162
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    • 2018
  • Objective: The fallopian tubes play a critical role in the early events of fertilization. The rapid innate immune defense is an important part of the fallopian tubes. Toll-like receptor 3 (TLR3), as a part of the innate immune system, plays an important role in detecting viral infections. In this basic and experimental study, the effect of sex hormones on the function of TLR3 in the OE-E6/E7 cell line was investigated. Methods: The functionality of TLR3 in this cell line was evaluated by cytokine measurements (interleukin [IL]-6 and IL-1b) and the effects of sex hormones on TLR3 were tested by an enzyme-linked immunosorbent assay kit. Additionally, TLR3 small interfering RNA (siRNA) and a TLR3 function-blocking antibody were used to confirm our findings. Results: The production of IL-6 significantly increased in the presence of polyinosinic-polycytidylic acid (poly(I:C)) as the TLR3 ligand. Using a TLR3-siRNA-ransfected OE-E6/E7 cell line and function-blocking antibody confirmed that cytokine production was due to TLR3. In addition, 17-${\beta}$ estradiol and progesterone suppressed the production of IL-6 in the presence and absence of poly(I:C). Conclusion: These results imply that sex hormones exerted a suppressive effect on the function of TLR3 in the fallopian tube cell line when different concentrations of sex hormones were present. The current results also suggest that estrogen receptor beta and nuclear progesterone receptor B are likely to mediate the hormonal regulation of TLR3, as these two receptors are the main estrogen and progesterone receptors in OEE6/E7 cell line.

Clusters of Toxoplasmosis in Ganghwa-gun, Cheorwon-gun, and Goseong-gun, Korea

  • Yu, Jihye;Kim, Woojin;Chang, Yoon Kyung;Kim, Tong-Soo;Hong, Sung-Jong;Ahn, Hye-Jin;Nam, Ho-Woo;Kim, Dongjae
    • Parasites, Hosts and Diseases
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    • 제59권3호
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    • pp.251-256
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    • 2021
  • We find out the clusters with high toxoplasmosis risk to discuss the geographical pattern in Gyodong-myeon and Samsan-myeon of Ganghwa-gun, Cheorwon-gun, and Goseong-gun, Korea. Seroepidemiological data of toxoplasmosis surveyed using rapid diagnostic tests for the residents in the areas in 2019 were analyzed to detect clusters of the infection. The cluster was investigated using the SaTScan program which is based on Kulldorff's scan statistic. The clusters were found with P-values in each region analyzed in the program, and the risk and patient incidence of specific areas can be examined by the values such as relative risk and log likelihood ratio. Jiseok-ri and Insa-ri were found to be a cluster in Gyodong-myeon and Seokmo-ri was the cluster in Samsan-myeon. Yangji-ri and Igil-ri were found to be a cluster in Cheorwon-gun and Madal-ri and Baebong-ri were the cluster in Goseong-gun. This findings can be used to monitor and prevent toxoplasmosis infections occurring in vulnerable areas.

Picropodophyllotoxin Induces G1 Cell Cycle Arrest and Apoptosis in Human Colorectal Cancer Cells via ROS Generation and Activation of p38 MAPK Signaling Pathway

  • Lee, Seung-On;Kwak, Ah-Won;Lee, Mee-Hyun;Seo, Ji-Hye;Cho, Seung-Sik;Yoon, Goo;Chae, Jung-Il;Joo, Sang Hoon;Shim, Jung-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제31권12호
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    • pp.1615-1623
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    • 2021
  • Picropodophyllotoxin (PPT), an epimer of podophyllotoxin, is derived from the roots of Podophyllum hexandrum and exerts various biological effects, including anti-proliferation activity. However, the effect of PPT on colorectal cancer cells and the associated cellular mechanisms have not been studied. In the present study, we explored the anticancer activity of PPT and its underlying mechanisms in HCT116 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to monitor cell viability. Flow cytometry was used to evaluate cell cycle distribution, the induction of apoptosis, the level of reactive oxygen species (ROS), assess the mitochondrial membrane potential (Δψm), and multi-caspase activity. Western blot assays were performed to detect the expression of cell cycle regulatory proteins, apoptosis-related proteins, and p38 MAPK (mitogen-activated protein kinase). We found that PPT induced apoptosis, cell cycle arrest at the G1 phase, and ROS in the HCT116 cell line. In addition, PPT enhanced the phosphorylation of p38 MAPK, which regulates apoptosis and PPT-induced apoptosis. The phosphorylation of p38 MAPK was inhibited by an antioxidant agent (N-acetyl-L-cysteine, NAC) and a p38 inhibitor (SB203580). PPT induced depolarization of the mitochondrial inner membrane and caspase-dependent apoptosis, which was attenuated by exposure to Z-VAD-FMK. Overall, these data indicate that PPT induced G1 arrest and apoptosis via ROS generation and activation of the p38 MAPK signaling pathway.

Evaluating the Effects of Dose Rate on Dynamic Intensity-Modulated Radiation Therapy Quality Assurance

  • Kim, Kwon Hee;Back, Tae Seong;Chung, Eun Ji;Suh, Tae Suk;Sung, Wonmo
    • 한국의학물리학회지:의학물리
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    • 제32권4호
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    • pp.116-121
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    • 2021
  • Purpose: To investigate the effects of dose rate on intensity-modulated radiation therapy (IMRT) quality assurance (QA). Methods: We performed gamma tests using portal dose image prediction and log files of a multileaf collimator. Thirty treatment plans were randomly selected for the IMRT QA plan, and three verification plans for each treatment plan were generated with different dose rates (200, 400, and 600 monitor units [MU]/min). These verification plans were delivered to an electronic portal imager attached to a Varian medical linear accelerator, which recorded and compared with the planned dose. Root-mean-square (RMS) error values of the log files were also compared. Results: With an increase in dose rate, the 2%/2-mm gamma passing rate decreased from 90.9% to 85.5%, indicating that a higher dose rate was associated with lower radiation delivery accuracy. Accordingly, the average RMS error value increased from 0.0170 to 0.0381 cm as dose rate increased. In contrast, the radiation delivery time reduced from 3.83 to 1.49 minutes as the dose rate increased from 200 to 600 MU/min. Conclusions: Our results indicated that radiation delivery accuracy was lower at higher dose rates; however, the accuracy was still clinically acceptable at dose rates of up to 600 MU/min.

Golgi Stress Response: New Insights into the Pathogenesis and Therapeutic Targets of Human Diseases

  • Won Kyu Kim;Wooseon Choi;Barsha Deshar;Shinwon Kang;Jiyoon Kim
    • Molecules and Cells
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    • 제46권4호
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    • pp.191-199
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    • 2023
  • The Golgi apparatus modifies and transports secretory and membrane proteins. In some instances, the production of secretory and membrane proteins exceeds the capacity of the Golgi apparatus, including vesicle trafficking and the post-translational modification of macromolecules. These proteins are not modified or delivered appropriately due to the insufficiency in the Golgi function. These conditions disturb Golgi homeostasis and induce a cellular condition known as Golgi stress, causing cells to activate the 'Golgi stress response,' which is a homeostatic process to increase the capacity of the Golgi based on cellular requirements. Since the Golgi functions are diverse, several response pathways involving TFE3, HSP47, CREB3, proteoglycan, mucin, MAPK/ETS, and PERK regulate the capacity of each Golgi function separately. Understanding the Golgi stress response is crucial for revealing the mechanisms underlying Golgi dynamics and its effect on human health because many signaling molecules are related to diseases, ranging from viral infections to fatal neurodegenerative diseases. Therefore, it is valuable to summarize and investigate the mechanisms underlying Golgi stress response in disease pathogenesis, as they may contribute to developing novel therapeutic strategies. In this review, we investigate the perturbations and stress signaling of the Golgi, as well as the therapeutic potentials of new strategies for treating Golgi stress-associated diseases.

Licochalcone H Targets EGFR and AKT to Suppress the Growth of Oxaliplatin -Sensitive and -Resistant Colorectal Cancer Cells

  • Seung-On Lee;Mee-Hyun Lee;Ah-Won Kwak;Jin-Young Lee;Goo Yoon;Sang Hoon Joo;Yung Hyun Choi;Jin Woo Park;Jung-Hyun Shim
    • Biomolecules & Therapeutics
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    • 제31권6호
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    • pp.661-673
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    • 2023
  • Treatment of colorectal cancer (CRC) has always been challenged by the development of resistance. We investigated the antiproliferative activity of licochalcone H (LCH), a regioisomer of licochalcone C derived from the root of Glycyrrhiza inflata, in oxaliplatin (Ox)-sensitive and -resistant CRC cells. LCH significantly inhibited cell viability and colony growth in both Ox-sensitive and Ox-resistant CRC cells. We found that LCH decreased epidermal growth factor receptor (EGFR) and AKT kinase activities and related activating signaling proteins including pEGFR and pAKT. A computational docking model indicated that LCH may interact with EGFR, AKT1, and AKT2 at the ATP-binding sites. LCH induced ROS generation and increased the expression of the ER stress markers. LCH treatment of CRC cells induced depolarization of MMP. Multi-caspase activity was induced by LCH treatment and confirmed by Z-VAD-FMK treatment. LCH increased the number of sub-G1 cells and arrested the cell cycle at the G1 phase. Taken together LCH inhibits the growth of Ox-sensitive and Ox-resistant CRC cells by targeting EGFR and AKT, and inducing ROS generation and ER stress-mediated apoptosis. Therefore, LCH could be a potential therapeutic agent for improving not only Ox-sensitive but also Ox-resistant CRC treatment.

Extracts of abalone intestine regulates fat metabolism in 3T3-L1 adipocytes and high fat diet-induced zebrafish larvae

  • Laxmi Sen Thakuri;Chul Min Park;Jin Yeong Choi;Hyeon-A Kim;Han Kyu Lim;Jin Woo Park;Dong Wook Kim;Dong Young Rhyu
    • Fisheries and Aquatic Sciences
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    • 제27권2호
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    • pp.122-135
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    • 2024
  • Obesity is a disease involving mechanisms of fat accumulation, low-grade inflammatory cytokine release, and mitochondrial dysfunction. The aim of the current study was to investigate the effects of abalone intestine extract on fat metabolism in 3T3-L1 adipocytes and high fat diet-induced zebrafish larvae. The total phenol content was highest in subcritical water extract at 210℃ (SW210) among hot water, ethanol, and subcritical water extracts of abalone intestine. In addition, SW210 of male abalone intestine (MASW210) most effectively controlled the lipid accumulation and expression of adipogenic or lipogenic regulators (PPAR-γ, C/EBPα, SREBP-1c, and FAS) in 3T3-L1 adipocytes. Likewise, in zebrafish larvae fed high fat, MASW210 significantly suppressed body weight, glucose levels, and lipid accumulation. The mRNA expression related to adipogenesis (PPAR-γ and C/EBPα), lipogenesis (SREBP-1c and FAS), inflammatory cytokines (TNF-α and IL-6), energy m/;.etabolism (AMPK, lepr, SIRT1, and adiponectin), and mitochondrial biogenesis (PGC-1α and CPT-1) were significantly regulated by treatment with MASW210. These results suggest that abalone intestine extract such as MASW210, are useful biomaterials for improving obesity and metabolic diseases.

낙동강 상주보와 금강중류 대청댐 주변으로부터 야생효모의 분리 및 국내 미기록 효모들의 균학적 특성 (Isolation of Wild Yeasts Obtained from Waters and Soils of Riversides in Sangjubo of Nakdong River and Daechung Dam of Geumgang Midstream, Korea and Characterization of Unrecorded Wild Yeasts)

  • 한상민;박동재;김지윤;임효진;이향범;이종수
    • 한국균학회지
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    • 제48권3호
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    • pp.237-249
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    • 2020
  • 경상북도 낙동강의 상주보와 금강중류인 대전시 신탄진의 대청댐주변의 야생효모들의 종 분포특성을 알아보기 위해 먼저 이들지역의 토양과 물들로부터 야생효모들을 분리, 동정하였다. 낙동강의 상주보에서 채취한 시료 47점에서 모두 39종 94 균주의 야생효모들이 분리, 동정되었고 Cryptococcus속 균들이 가장 많았다. 이들중Rhodosporidium azoricum JSL-GRU-009를 포함한 3균주들이 아직까지 국내에 보고되지 않은 미기록 효모들로 최종 선별되었다. 또한, 금강중류지역인 대전시 신탄진의 대청대교와 대청댐주변 토양과 물등 130종의 시료들로부터 105종 209균주들이 분리, 동정되었고 이들 야생효모 균주들로부터 Bullera pseudoalba JSL-GRU-005를 포함한 10종의 균들이 국내 미기록 효모들로 최종 선별되었다. 이들 낙동강 상주보와 대청댐등에서 선별된 13균주들의 균학적 특성을 조사한 결과 이들 미기록 균주들은 구형~타원형으로 출아, 분열법으로 영양 증식하였다. R. azoricum JSL-GRU를 포함한 9균주들이 포자를 형성하였고 10균주들이 비타민을 첨가하지 않은 YPD 배지에서 생육하였다.R. azoricum JSL-GR균주는 20% 포도당을 함유한 YPD 배지에서 잘 생육하였고, R. oryzicola JSL-GRU-003를 포함한 3 균주는 5% NaCl을 함유한 YPD 배지에서 생육하였다.