• Molecules and Cells
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• 제46권4호
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• pp.219-230
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• 2023

Down syndrome (DS) is the most common autosomal aneuploidy caused by trisomy of chromosome 21. Previous studies demonstrated that DS affected mitochondrial functions, which may be associated with the abnormal development of the nervous system in patients with DS. Runt-related transcription factor 1 (RUNX1) is an encoding gene located on chromosome 21. It has been reported that RUNX1 may affect cell apoptosis via the mitochondrial pathway. The present study investigated whether RUNX1 plays a critical role in mitochondrial dysfunction in DS and explored the mechanism by which RUNX1 affects mitochondrial functions. Expression of RUNX1 was detected in induced pluripotent stem cells of patients with DS (DS-iPSCs) and normal iPSCs (N-iPSCs), and the mitochondrial functions were investigated in the current study. Subsequently, RUNX1 was overexpressed in N-iPSCs and inhibited in DS-iPSCs. The mitochondrial functions were investigated thoroughly, including reactive oxygen species levels, mitochondrial membrane potential, ATP content, and lysosomal activity. Finally, RNA-sequencing was used to explore the global expression pattern. It was observed that the expression levels of RUNX1 in DS-iPSCs were significantly higher than those in normal controls. Impaired mitochondrial functions were observed in DS-iPSCs. Of note, overexpression of RUNX1 in N-iPSCs resulted in mitochondrial dysfunction, while inhibition of RUNX1 expression could improve the mitochondrial function in DS-iPSCs. Global gene expression analysis indicated that overexpression of RUNX1 may promote the induction of apoptosis in DS-iPSCs by activating the PI3K/Akt signaling pathway. The present findings indicate that abnormal expression of RUNX1 may play a critical role in mitochondrial dysfunction in DS-iPSCs.

• Animal Bioscience
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• 제34권10호
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• pp.1590-1599
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• 2021

Objective: This study investigates the expression patterns of toll-like receptors (TLRs) and intracellular mediators in horse muscle cells after exercise, and the relationship between TLRS expression in stressed horse muscle cells and immune cell migration toward them. Methods: The expression patterns of the TLRs (TLR2, TLR4, and TLR8) and downstream signaling pathway-related genes (myeloid differentiation primary response 88 [MYD88]; activating transcription factor 3 [ATF3]) are examined in horse tissues, and horse peripheral blood mononuclear cells (PBMCs), polymorphonuclear cells (PMNs) and muscles in response to exercise, using the quantitative reverse transcription-polymerase chain reaction (qPCR). Expressions of chemokine receptor genes, i.e., C-X-C motif chemokine receptor 2 (CXCR2) and C-C motif chemokine receptor 5 (CCR5), are studied in PBMCs and PMNs. A horse muscle cell line is developed by transfecting SV-T antigen into fetal muscle cells, followed by examination of muscle-specific genes. Horse muscle cells are treated with stressors, i.e., cortisol, hydrogen peroxide (H₂O₂), and heat, to mimic stress conditions in vitro, and the expression of TLR4 and TLR8 are examined in stressed muscle cells, in addition to migration activity of PBMCs toward stressed muscle cells. Results: The qPCR revealed that TLR4 message was expressed in cerebrum, cerebellum, thymus, lung, liver, kidney, and muscle, whereas TLR8 expressed in thymus, lung, and kidney, while TLR2 expressed in thymus, lung, and kidney. Expressions of TLRs, i.e., TLR4 and TLR8, and mediators, i.e., MYD88 and ATF3, were upregulated in muscle, PBMCs and PMNs in response to exercise. Expressions of CXCR2 and CCR5 were also upregulated in PBMCs and PMNs after exercise. In the muscle cell line, TLR4 and TLR8 expressions were upregulated when cells were treated with stressors such as cortisol, H₂O₂, and heat. Migration of PBMCs toward stressed muscle cells was increased by exercise and oxidative stresses, and combinations of these. Treatment with methylsulfonylmethane (MSM), an antioxidant on stressed muscle cells, reduced migration of PBMCs toward stressed muscle cells. Conclusion: In this study, we have successfully cultured horse skeletal muscle cells, isolated horse PBMCs, and established an in vitro system for studying stress-related gene expressions and function. Expression of TLR4, TLR8, CXCR2, and CCR5 in horse muscle cells was higher in response to stressors such as cortisol, H₂O₂, and heat, or combinations of these. In addition, migration of PBMCs toward muscle cells was increased when muscle cells were under stress, but inhibition of reactive oxygen species by MSM modulated migratory activity of PBMCs to stressed muscle cells. Further study is necessary to investigate the biological function(s) of the TLR gene family in horse muscle cells.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2453-2458
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• 2015

Background: X-linked inhibitor of apoptosis protein (XIAP) associated factor 1 (XAF1) exhibits aberrantly low or absent expression in various human malignancies, closely associated with anti-apoptosis and overgrowth of cancer cells. However, limited attention has been directed towards the contribution of XAF1 to invasion, apoptosis, and cisplatin (DDP)-resistance of epithelial ovarian cancer (EOC) cells. This study aimed to evaluate the potential effects of XAF1 on invasion, cell cycle, apoptosis, and cisplatin-resistance by overexpressing XAF1 in SKOV-3 and SKOV-3/DDP cells. Methods and Results: The pEGFP-C1-XAF1 plasmid was transfected into SKOV-3 and SKOV-3/DDP cells, and the expression of XAF1 at both mRNA and protein levels was analyzed by reverse transcription-PCR and Western blotting. Overexpression of XAF1 suppressed XIAP expression in both SKOV-3 and SKOV-3/DDP cells. Transwell invasion assays demonstrated that XAF1 exerted a strong anti-invasive effect in XAF1-overexpressing cells. Moreover, flow cytometry analysis revealed that XAF1 overexpression arrested the cell cycle at G0/G1 phase, and cell apoptosis analysis showed that overexpression of XAF1 enhanced apoptosis of SKOV-3 and SKOV-3/DDP cells apparently by activating caspase-9 and caspase-3. Furthermore, MTT assay confirmed a dose-dependent inhibitory effect of cisplatin in the tested tumor cells, and overexpression of XAF1 increased the sensitivity of SKOV-3 and SKOV-3/DDP cells to cisplatin-mediated antiproliferative effects. Conclusions: In summary, our data indicated that overexpression of XAF1 could suppress XIAP expression, inhibit invasion, arrest cell cycle, promote apoptosis, and confer cisplatin-sensitivity in SKOV-3 and SKOV-3/DDP cells. Therefore, XAF1 may be further assessed as a potential target for the treatment of both cisplatin-resistant and non-resistant EOCs.

• Tuberculosis and Respiratory Diseases
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• 제75권4호
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• pp.140-149
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• 2013

Background: Plasminogen activator inhibitor type 1 (PAI-1), an important regulator of plasminogen activator system which controls degradation of extracellular membrane and progression of tumor cells, and PAI-1 gene polymorphic variants have been known as the prognostic biomarkers of non-small cell lung cancer patients. Recently, experimental in vitro study revealed that transforming growth factor-${\beta}1$ initiated PAI-1 transcription through epithelial growth factor receptor (EGFR) signaling pathway. However, there is little clinical evidence on the association between PAI-1 A15T gene polymorphism and prognosis of Korean population with pulmonary adenocarcinoma and the influence of activating mutation of EGFR kinase domain. Methods: We retrospectively reviewed the medical records of 171 patients who were diagnosed with pulmonary adenocarcinoma and undergone EGFR mutation analysis from 1995 through 2009. Results: In all patients with pulmonary adenocarcinoma, there was no significant association between PAI-1 A15T polymorphic variants and prognosis for overall survival. However, further subgroup analysis showed that the group with AG/AA genotype had a shorter 3-year survival time than the group with GG genotype in patients with EGFR mutant-type pulmonary adenocarcinoma (mean survival time, 24.9 months vs. 32.5 months, respectively; p=0.015). In multivariate analysis of 3-year survival for patients with pulmonary adenocarcinoma harboring mutant-type EGFR, the AG/AA genotype carriers had poorer prognosis than the GG genotype carriers (hazard ratio, 7.729; 95% confidence interval, 1.414-42.250; p=0.018). Conclusion: According to our study of Korean population with pulmonary adenocarcinoma, AG/AA genotype of PAI-1 A15T would be a significant predictor of poor short-term survival in patients with pulmonary adenocarcinoma harboring mutant-type EGFR.

• 생명과학회지
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• 제30권3호
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• pp.285-290
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• 2020

구제역바이러스(FMDV)는 Picornaviridae 과의 Aphthovirus 속의 한 종류이며, 야생과 가축의 소와 돼지에 감염한다. FMDV는 감염 조직에서 중증의 염증반응을 포함한 다양한 임상적 증후들을 일으킨다. FMDV 게놈 RNA는 약 8.3 kb 길이의 양성-단일 가닥을 가지고 있으며, 하나의 긴 단백질 번역틀(ORF)을 만든다. 이 ORF는 바이러스의 단백질가수분해효소에 의해서 구조단백질과 비구조단백질로 나누어진다. FMDV의 FMDV 2C 단백질은 FMDV 유전자에서 만들어지는 비구조단백질로서 염증과 세포사를 포함한 FMD 병리 과정과 바이러스 복제에서 중요한 역할을 한다. 이 연구에서 우리는 FMDV 2C가 염증 유도 사이토카인인 tumor necrosis factor alpha (TNFα)의 세포내 발현을 유도하는 가능성을 검토하였다. FMDV 2C의 돼지 세포인 IBRS-2 세포내 발현은 TNFα의 유전자 발현 조절 부위인 프로모터의 활성화를 이용하여 전사수준에서 TNFα의 mRNA와 단백질 생성을 증가시켰다. 추가적으로, 소포체 스트레스를 감소시키는 화학물질인 4-phenylbutyric acid (4-PBA) 처리는 FMDV 2C에 의해 유도된 TNFα 발현을 감소시켰다. 소포체 스트레스 반응을 매개하는 전사인자의 한 종류인 ATF4는 TNFα 프로모터의 활성을 유도하고, TNFα의 mRNA와 단백질 발현을 증가시켰다. 하지만, ATF4의 기능 결핍 돌연변이체 단백질의 발현은 FMDV 2C에 의한 TNFα 생성을 유도하지 못하였다. 이들 결과들은 FMDV FMDV 2C 단백질이 ATF4-매개 TNFα 발현을 통해 임상적 염증반응을 증가시키고, 이는 소포체 스트레스의 유도와 연관되어있음을 제시한다.

• Clinical and Experimental Reproductive Medicine
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• 제23권3호
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• pp.269-275
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• 1996

Biosynthesis and secretion of anterior pituitary hormones are under the control of specific hypothalamic stimulatory and inhibitory factors. Among them, Growth Hormone Releasing Hormone (GHRH) is the major stimulator of pituitary somatotrophs activating GH gene expression and secretion. Human GHRH is a polypeptide of 44 amino acids initially isolated from pancreatic tumors, and the gene for the hypothalamic form of GHRH is organized into 5 exons spanning over 10 kilobases (kb) on genomic DNA and encodes a messenger RNA of 700-750 nucleotides. Several neuropeptides classically associated with the hypothalamus have been found in the extrahypothalamic regions, suggesting the existence of novel sources, targets and functions. GHRH-like immunoreactivity has been found in several peripheral sites, including placenta, testis, and ovary, indicating that GHRH may also have regulatory roles in peripheral reproductive organs. Furthermore, higher molecular weight forms of the GHRH transcripts were identified from these organs (1.75 kb in testis; 1.75 and >3 kb in ovary). These tissue-specific expression of GHRH gene suggest the existence of unique regulatory mechanism of GHRH expression and function in these organs. In fact, placenta-specific and testis-specific promoters for GHRH transcripts which are located in about 10 kb upstream region of hypothalamic promoter were reported. The use of unique promoters in extrahypothalamic sites could be refered in a different control of GHRH gene and different functions of the translated products in these tissues. Somatotrophs and lactotrophs have been thought to be derived from a common bipotential progenitor, the somatolactotrophs, which give origins to either phenotypes. Although the precise mechanism responsible for the lactotroph differentiation in the anterior pituitary gland has not been yet clalified, there are several candidators for the generation of lactotrophs. In human, the presence of GHRH peptides with different size from authentic hypothalamic form in the normal anterior pituitary and several types of adenoma were demonstrated. Recently our group found the existence of immunoreactive GHRH and its transcript from the normal rat anterior pituitary (gonadotroph> somatotroph> lactotroph), and the GHRH treatment evoked the increased proliferation rate of anterior pituitary cells in vitro. The transgenic mouse models clearly shown that GHRH or NGF overexpression by anterior pituitary cells induced development of pituitary hyperplasia and adenomas particularly GH-oma and prolactinoma. Taken together, we hypothesize that the pituitary GHRH could serve not only as a modulator of hormone secretion but as a paracrine or autocrine regulator of anterior pituitary cell proliferation and differentiation. Interestingly enough, the expression of Pit-1 homeobox gene (the POU class transcription factor) was confined to somatotrophs, lactotrophs and somatolactotrophs in which GHRH receptors are expressed commonly. Concerning the mechanism of somatolactotroph and lactotroph differentiation in the anterior pituitary, we have focused following two possibilities; (1) changes in the relative levels or interactions of both hypothalamic and intrapituitary factors such as dopamine, VIP, somatostatin, NGF and GHRH; (2) alterations of GHRH-GHRH receptor signaling and Pit-1 activity may be the cause of lactotroph differentiation or pituitary hyperplasia and adenoma formation. Extensive further studies will be necessary to solve these complicated questions.

• 생명과학회지
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• 제22권4호
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• pp.492-498
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• 2012

파이토케미칼이 암 세포 성장에 미치는 영향을 확인하기 위하여, 대장암 세포주 HCT116에 네 종류의 파이토케미칼을 각각 25 ${\mu}M$의 농도로 처리하였다. 처리한 파이토케미칼 중 curcumin이 가장 강력하게 세포 성장을 억제하였다. 또한 curcumin은 농도의존적으로 세포 성장을 억제하였다. Curcumin에 의한 대장암 세포주 성장 저해 활성에 대한 분자생물학적 기전을 연구하기 위하여 oligo DNA microarray 실험을 수행하였다. 그 결과, 25 ${\mu}M$ curcumin 처리에 의해 2배 이상 발현이 증가된 유전자 137개, 발현이 감소된 유전자 141개를 선별하였다. 발현이 증가된 유전자 중, 세포사멸과 밀접한 관련이 있는 것으로 알려진 유전자 3개를 선택하여, RT-PCR을 통해 이들 유전자의 발현이 감소됨을 확인하였다. 처리한 파이토케미칼 중 curcumin은 가장 강력한 ATF3의 유도자였으며, 농도의존적으로 ATF3의 발현을 증가시켰다. 흥미롭게도, curcumin에 의한 성장 저해는 ATF3-siRNA에 의한 ATF3 유전자 발현감소에 의해 성장이 회복되었다. 또한, ATF3 유전자의 과대발현 후 발현이 변화되는 유전자를 선별한 결과, 세포사멸과 관련된 많은 유전자들이 증가됨을 확인하였다. 결론적으로, 대장암 세포주에서 curcumin에 의한 항 성장활성에 있어서 ATF3 유전자가 중요한 역할을 할 것으로 생각된다.

• 생명과학회지
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• 제29권6호
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• pp.645-652
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• 2019

전세계적으로 폐암 발병율은 서서히 감소하는 추세이지만, 여전히 암 관련 사망의 주요 원인으로 지목되고 있으며, 이에 따라 폐암 진단과 치료를 위한 새로운 분자적 지표를 발굴하는 연구가 활발히 이루어지고 있다. 본 연구진이 수행한 기존 연구에 따르면 폐암 환자에게서는 전사인자 중 하나인 TFAP2C가 높은 비율로 발현되며, 이 전사인자를 통해 폐암 발달에 상당한 영향을 끼치는 것을 확인할 수 있었다. TFAP2C는 다른 유전자들의 발현을 조절하여 암 형성에 기여하게 된다. 마이크로어레이 분석을 통해 TFAP2C에 의해 발현양이 조절되는 잠재적 표적 유전자들을 확인하였고, 특히 TFAP2C siRNA를 처리하였을 때 발현이 감소되는 원암유전자들 중 CDC20과 TRIB3 유전자를 최종적으로 선별하였다. 리얼타임 qRT-PCR과 웨스턴블롯을 통하여 두 유전자가 TFAP2C에 의존적으로 발현됨을 확인하였으며, 세포 생존 분석법을 통하여 CDC20과 TRIB3의 발현 증가가 폐암세포의 세포 증식을 유의미하게 유도하는 것을 확인하였다. 이와 더불어, CDC20과 TRIB3의 과발현이 폐암세포의 세포사멸 수준을 감소시켜 폐암 형성에 관여함을 확인하였다. 본 연구를 통하여 CDC20과 TRIB3가 폐암 형성을 유도할 수 있는 잠재적인 원암유전자로 기능함을 밝힐 수 있었으며, 두 유전자가 폐암 진단을 위한 표적유전자로서의 역할을 수행할 수 있을 것으로 기대한다.

• Anatomy and Cell Biology
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• 제57권3호
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• pp.408-418
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• 2024

Vitamin C is a well-known antioxidant with antiviral, anticancer, and anti-inflammatory properties based on its antioxidative function. Aptamin C, a complex of vitamin C with its specific aptamer, has been reported to maintain or even enhance the efficacy of vitamin C while increasing its stability. To investigate in vivo distribution of Aptamin C, Gulo knockout mice, which, like humans, cannot biosynthesize vitamin C, were administered Aptamin C orally for 2 and 4 weeks. The results showed higher vitamin C accumulation in all tissues when administered Aptamin C, especially in the spleen. Next, the activity of natural killer (NK) cells were conducted. CD69, a marker known for activating for NK cells, which had decreased due to vitamin C deficiency, did not recover with vitamin C treatment but showed an increasing with Aptamin C. Furthermore, the expression of CD107a, a cell surface marker that increases during the killing process of target cells, also did not recover with vitamin C but increased with Aptamin C. Based on these results, when cultured with tumor cells to measure the extent of tumor cell death, an increase in tumor cell death was observed. To investigate the signaling mechanisms and related molecules involved in the proliferation and activation of NK cells by Aptamin C showed that Aptamin C treatment led to an increase in intracellular STAT3 activation. In conclusion, Aptamin C has a higher capability to activate NK cells and induce tumor cell death compared to vitamin C and it is mediated through the activation of STAT3.

• 대한의생명과학회지
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• 제9권2호
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• pp.59-65
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• 2003

When cells are exposed to proteotoxic stresses such as heat shock, amino acid analogs, and heavy metals, they increase the synthesis of the heat shock proteins (HSPs) by activating the heat shock transcription factor 1 (HSF1), whose activity is controlled via multiple steps including homotrimerization, nuclear translocation, DNA binding, and hyperphosphorylation. Under unstressed conditions, the HSF1 activity is repressed through its constitutive phosphorylation by glycogen synthase kinase 3$\beta$ (GSK3$\beta$), extracellular regulated kinase 1/2 (ERK1/2), and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). However, the protein kinase (s) responsible for HSF1 hyperphosphorylation and activation is not yet identified. In the present study, we observed that profile of p38 mitogen-activated protein kinase (p38MAPK) activation in response to heat shock was very similar to those of HSF1 hyperphosphorylation and nuclear translocation. Therefore, we investigated whether p38MAPK is involved in the heat shock-induced HSF1 activation and HSP expression. Here we show that the p38MAPK inhibitors, SB202190 and SB203580, but not other inhibitors including the MEK1/2 inhibitor PD98059 and the PI3-K inhibitor LY294002 and wortmannin, suppress HSF1 hyperphosphorylation in response to heat shock and L-azetidine 2-carboxylic acid (Azc), but not to heavy metals. Furthermore, heat shock-induced HSF1-DNA binding and HSP72 expression was specifically prevented by the p38MAPK inhibitors, but not by the MEK1/2 inhibitor and the PI3-K inhibitors. These results suggest that SB202190- and SB203580-sensitive p38MAPK may positively regulate HSP gene regulation in response to heat shock and amino acid analogs.