• Nutrition Research and Practice
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• v.11 no.2
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• pp.83-89
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• 2017

BACKGROUND/OBJECTIVES: Epithelial-mesenchymal transition (EMT) is involved in not only cancer development and metastasis but also non-cancerous conditions. Hypoxia is one of the proposed critical factors contributing to formation of chronic rhinosinusitis or nasal polyposis. Wheatgrass (Triticum aestivum) has antioxidant, anti-aging, and anti-inflammatory effects. In this study, we analyzed whether wheatgrass has an inhibitory effect on the EMT process in airway epithelial cells. MATERIALS/METHODS: A549 human lung adenocarcinoma cells were incubated in hypoxic conditions ($CO_2$ 5%/$O_2$ 1%) for 24 h in the presence of different concentrations of wheatgrass extract (50, 75, 100, and $150{\mu}g/mL$) and changes in expression of epithelial or mesenchymal markers were evaluated by immunoblotting and immunofluorescence. Accordingly, associated EMT-related transcriptional factors, Snail and Smad, were also evaluated. RESULTS: Hypoxia increased expression of N-cadherin and reduced expression of E-cadherin. Mechanistically, E-cadherin levels were recovered during hypoxia by silencing hypoxia inducible factor (HIF)-$1{\alpha}$ or administering wheatgrass extract. Wheatgrass inhibited the hypoxia-mediated EMT by reducing the expression of phosphorylated Smad3 (pSmad3) and Snail. It suppressed the hypoxia-mediated EMT processes of airway epithelial cells via HIF-$1{\alpha}$ and the pSmad3 signaling pathway. CONCLUSION: These results suggest that wheatgrass has potential as a therapeutic or supplementary agent for HIF-1-related diseases.

• Molecules and Cells
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• v.43 no.11
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• pp.945-952
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• 2020

Hypoxia induces the expression of several genes through the activation of a master transcription factor, hypoxia-inducible factor (HIF)-1α. This study shows that hypoxia strongly induced the expression of two carboxypeptidases (CP), CPA4 and CPE, in an HIF-1α-dependent manner. The hypoxic induction of CPA4 and CPE gene was accompanied by the recruitment of HIF-1α and upregulation in the active histone modification, H3K4me3, at their promoter regions. The hypoxic responsiveness of CPA4 and CPE genes was observed in human adipocytes, human adipose-derived stem cells, and human primary fibroblasts but not mouse primary adipocyte progenitor cells. CPA4 and CPE have been identified as secreted exopeptidases that degrade and process other secreted proteins and matrix proteins. This finding suggests that hypoxia changes the microenvironment of the obese hypoxic adipose tissue by inducing the expression of not only adipokines but also peptidases such as CPA4 and CPE.

• Molecules and Cells
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• v.44 no.10
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• pp.710-722
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• 2021

Hypoxia, or low oxygen tension, is a hallmark of the tumor microenvironment. The hypoxia-inducible factor-1α (HIF-1α) subunit plays a critical role in the adaptive cellular response of hypoxic tumor cells to low oxygen tension by activating gene-expression programs that control cancer cell metabolism, angiogenesis, and therapy resistance. Phosphorylation is involved in the stabilization and regulation of HIF-1α transcriptional activity. HIF-1α is activated by several factors, including the mitogen-activated protein kinase (MAPK) superfamily. MAPK phosphatase 3 (MKP-3) is a cytoplasmic dual-specificity phosphatase specific for extracellular signal-regulated kinase 1/2 (Erk1/2). Recent evidence indicates that hypoxia increases the endogenous levels of both MKP-3 mRNA and protein. However, its role in the response of cells to hypoxia is poorly understood. Herein, we demonstrated that small-interfering RNA (siRNA)-mediated knockdown of MKP-3 enhanced HIF-1α (not HIF-2α) levels. Conversely, MKP-3 overexpression suppressed HIF-1α (not HIF-2α) levels, as well as the expression levels of hypoxia-responsive genes (LDHA, CA9, GLUT-1, and VEGF), in hypoxic colon cancer cells. These findings indicated that MKP-3, induced by HIF-1α in hypoxia, negatively regulates HIF-1α protein levels and hypoxia-responsive genes. However, we also found that long-term hypoxia (>12 h) induced proteasomal degradation of MKP-3 in a lactic acid-dependent manner. Taken together, MKP-3 expression is modulated by the hypoxic conditions prevailing in colon cancer, and plays a role in cellular adaptation to tumor hypoxia and tumor progression. Thus, MKP-3 may serve as a potential therapeutic target for colon cancer treatment.

• Journal of fish pathology
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• v.33 no.1
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• pp.35-43
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• 2020

Hypoxia is a serious problem in the marine ecosystem causing a decline in aquatic resources. MicroRNAs (miRNAs) regulate the expression of genes through binding to the corresponding sequences of their target mRNAs. Especially, miRNAs in the cytoplasm can be secreted into body fluids, which called circulating miRNAs, and the availability of circulating miRNAs as biomarkers for hypoxia has been demonstrated in mammals. However, there has been no report on the hypoxia-mediated changes in the circulating miRNAs in fish. miR-210 is known as the representative hypoxia-responsive circulating miRNA in mammals. To know whether fish miR-210 also respond to hypoxia, we analyzed the change of circulating miR-210 quantity in the serum of olive flounder (Paralichthys olivaceus) in response to hypoxia. The expression of hypoxia related genes, hypoxia inducible factor 1α (HIF-1α) and the heat shock protein 90α (HSP90α) was also analyzed. Similar to the reports from mammals, miR-210-5p and miR-210-3p were significantly increased in the serum of olive flounder in response to hypoxia, suggesting that circulating miR-210 levels in the serum can be used as a noninvasive prognostic biomarker for fish suffered hypoxia. The target genes of miR-210 were related to various biological processes, which explains the major regulatory role of miR-210 in response to hypoxia. The expression of HIF-1α and HSP90α in the tissues was also up-regulated by hypoxia. Considering the critical role of HIF-1α in miR-210 expression and HSP90 in miRNAs function, the present up-regulation of HIF-1α and HSP90α might be related to the increase of circulatory miR-210, and the interaction mechanism among HIF-1α, HSP90α, and hypoxia-responsive microRNAs in fish should be further studied.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.53-62
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• 2016

Mesenchymal stem cells (MSCs) in the bone marrow and other somatic tissues reside in an environment with relative low oxygen tension. Cobalt chloride ($CoCl_2$) can mimic hypoxic conditions through transcriptional changes of some genes including hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) and vascular endothelial growth factor (VEGF). This study evaluated the potential role of $CoCl_2$ preconditioning on multi-lineage differentiation of C3H/10T1/2, a murine MSC line to understand its possible molecular mechanisms in vitro. $CoCl_2$ treatment of MSCs markedly increased HIF-$1{\alpha}$ and VEGF mRNA, and protein expression of HIF-$1{\alpha}$. Temporary preconditioning of MSCs with $CoCl_2$ induced up-regulation of osteogenic markers including alkaline phosphatase, osteocalcin, and type I collagen during osteogenic differentiation, followed by enhanced mineralization. $CoCl_2$ also increased chondrogenic markers including aggrecan, sox9, and type II collagen, and promoted chondrocyte differentiation. $CoCl_2$ suppressed the expression of adipogenic markers including $PPAR{\gamma}$, aP2, and $C/EBP{\alpha}$, and inhibited adipogenesis. Temporary preconditioning with $CoCl_2$ could affect the multi-lineage differentiation of MSCs.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.3 s.31
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• pp.22-33
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• 2006

Objective : Angiogenesis induced by hypoxia and inflammation are an essential process of solid tumors and psoriasis. We researched the HIF-1 ${\alpha}$ (hypoxia inducible factor 1 alpha), VEGF(Vascular Endothelial Growth Factor), survival related PI3K-Akt, and inflammation related COX-2 protein expressions to get the information of the mechanism and effects of Rehmannia glutinosa in HepG2 and HaCaT cell lines. Method : To investigate the roles of the Rehmannia glutinosa extract, we performed MTS assay and western blots using HaCaT cells and HepG2 cells. HaCaT cells and HepG2 cells were treated with $50{\mu}g/ml$ and $100{\mu}g/ml$ Rehmannia glutinosa extracts. After 4hrs, HaCaT cells were treated with IGF-II protein for 24hrs and HepG2 cells were treated with $CoCl_2$. Results : 1. We could ohserve that the reduction of the protein level of HIT-1 ${\alpha}$ induced by IGF-II in HaCaT cells. 2. We Could ohserve that the decreased PI3K-Akt and COX-2 expression level by Rehmannia glutinosa extracts treated in HaCaT cells independently ith ERK1/2. 3. We could observe that the reduction of the protein level of HIF-1 ${\alpha}$ induced by $CoCl_2$ in HepG2 cells. Conclusion : These results suggest that Rehmannia glutinosa extracts contributes to the anti-survival pathway and anti-inflammatory activities. Also, we could assume that Rehmannia glutinosa act as anti-inflanmmatory or anti-hypoxia agents via reduction of COX-2 and HIF-1 ${\alpha}$.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9973-9978
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• 2014

Background: Hypoxia inducible factor-1 alpha (HIF-$1{\alpha}$) is the key regulator of cellular responses to hypoxia and plays a central role in tumour growth. Presence of Single nucleotide polymorphisms (SNPs) in the critical regulatory domains of HIF-$1{\alpha}$ may result in the overexpression of the protein and subsequent changes in the expression of the downstream target genes. The aim of study was to investigate the association of three SNPs (g.C111A, g.C1772T and g.G1790A) of HIF-$1{\alpha}$ with the risk of breast cancer in North Indian sporadic breast cancer patients. Materials and Methods: A total of 400 subjects, including 200 healthy controls and 200 patients with breast cancer were recruited in this study. Genotypes were determined using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method. Results: The CC and CA genotype frequency of HIF-$1{\alpha}$ g.C111A polymorphism was 100 vs 99% and 0 vs 1% in breast cancer patients and healthy controls respectively. The frequencies of CC, CT and TT genotype of g.C1772T polymorphism were 76 vs 74.5%, 19 vs 21% and 5 vs 4.5% in breast cancer patients and control individuals respectively. There was no significant difference in genotype and allele frequencies of HIF-$1{\alpha}$ g.C1772T polymorphism between cases and control individuals (p>0.05). For g.G1790A genotypes, all patients and controls had only GG genotype. Conclusions: The three HIF-$1{\alpha}$ polymorphisms (g.C111A, g.C1772T and g.G1790A) are not associated with breast cancer risk in North-West Indian patients.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.691-701
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• 2004

Background: Tissue hypoxia is a characteristic of many human malignant neoplasms, and hypoxia inducible factor-1 (HIF-1) plays a pivotal role in essential adaptive response to hypoxia, and activates a signal pathway for the expression of the hypoxia-regulated genes, resulting in increased oxygen delivery or facilitating metabolic adaptation to hypoxia. Increased level of HIF-1 a has been reported in many human malignancies, but in esophageal squamous cell carcinoma, the influence of HIF-1 a on tumor biology, including neovascularization, is not still defined. Material and Method: The influence of HIF-1 a expression on angiogenic factors, correlation between the tumor proliferation and HIF-1 a expression, interaction of HIF-1 a expression and p53, and correlation between HIF-1 a expression and clinicopathological prognostic parameters were investigated, using immunohistochemical stains for HIF-1 a, VEGF, CD34, p53, and Ki-67 on 77 cases of resected esophageal squamous cell carcinoma. Result: HIF-1 a expression in cancer cells was found in 33 of 77 esophageal squamous cell carcinoma cases. The 33 cases (42.9%) showed positive stain for HIF-1 a. High HIF-1 a expression was significantly associated with several pathological parameters, such as histologic grade (p=0.032), pathological TMN stage (p=0.002), the depth of tumor invasion (p=0.022), regional lymph node metastasis (p=0.002), distant metastasis (p=0.049), and lymphatic invasion (p=0.004). High HIF-1 a expression had significant VEGF immunoreactivity (p=0.008) and Ki-67 labeling index (p<0.001), but was not correlated with microvascular density within tumors (p=0.088). The high HIF-1 a expression was correlated with aberrant p53 accumulation with a marginal significance (p=0.056). The overall 5-year survival rate was 34.9%. The survival rate of patients with a high HIF-1 a expression was worse than that of patients with low-expression tumors (log-rank test, p=0.0001). High HIF-1 a expression was independent unfavorable factors although statistical significance is marginal in multivariate analysis. Conclusion: It is suggested that (1) high HIF-1 a expression in esophageal squamous cell carcinoma is associated with tumor hypoxia, or with genetic alteration in early carcinogenesis and progressive stages, (2) high HIF-1 a expression may be associated with intratumoral neovascularization through HIF-VEGF pathway, and (3) high HIF-1 a expression is associated with poor prognosis in patients with esophageal squamous cell carcinoma and may playa role as biomarker for regional lymph node metastasis.

• Molecules and Cells
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• v.28 no.6
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• pp.537-543
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• 2009

Keratinocyte overgrowth after UVB exposure is believed to contribute to skin photoageing and cancer development. However, little is known about the transcription factors that epigenetically regulate keratinocyte response to UVB. Recently, $HIF-1{\alpha}$ was found to play a role in epidermal homeostasis by controlling the keratinocyte cell cycle, and thus, we hypothesized that $HIF-1{\alpha}$ is involved in UVB-induced keratinocyte growth. In cultured keratinocytes, $HIF-1{\alpha}$ was found to be down-regulated shortly after UVB exposure and to be involved in UVB-induced proliferation. In mice repeatedly treated with UVB, the epidermis became hyperplasic and keratinocytes lacked $HIF-1{\alpha}$ in nuclei. Based on these results, we suggest that the deregulation of $HIF-1{\alpha}$ is associated with UVB-induced hyperplasia of the epidermis. This work provides insight of the molecular mechanism underlying UV-induced photoageing and skin cancer development.

• Biomolecules & Therapeutics
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• v.30 no.5
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• pp.465-472
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• 2022

Melanoma is one of the most aggressive skin cancers. Hypoxia contributes to the aggressiveness of melanoma by promoting cancer growth and metastasis. Upregulation of cyclin D1 can promote uncontrolled cell proliferation in melanoma, whereas stimulation of cytotoxic T cell activity can inhibit it. Epithelial mesenchymal transition (EMT) plays a critical role in melanoma metastasis. Hypoxia-inducible factor-1α (HIF-1α) is a main transcriptional mediator that regulates many genes related to hypoxia. CoCl₂ is one of the most commonly used hypoxia-mimetic chemicals in cell culture. In this study, inhibitory effects of IDF-11774, an inhibitor of HIF-1α, on melanoma growth and metastasis were examined using cultured B16F10 mouse melanoma cells and nude mice transplanted with B16F10 melanoma cells in the presence or absence of CoCl₂-induced hypoxia. IDF-11774 reduced HIF-1α upregulation and cell survival, but increased cytotoxicity of cultured melanoma cells under CoCl₂-induced hypoxia. IDF-11774 also reduced tumor size and local invasion of B16F10 melanoma in nude mice along with HIF-1α downregulation. Expression levels of cyclin D1 in melanoma were increased by CoCl₂ but decreased by IDF-11774. Apoptosis of melanoma cells and infiltration of cytotoxic T cells were increased in melanoma after treatment with IDF-11774. EMT was stimulated by CoCl₂, but restored by IDF11774. Overall, IDF-11774 inhibited the growth and metastasis of B16F10 melanoma via HIF-1α downregulation. The growth of B16F10 melanoma was inhibited by cyclin D1 downregulation and cytotoxic T cell stimulation. Metastasis of B16F10 melanoma was inhibited by EMT suppression.