• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.828-837
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• 2006

Background: Tissue hypoxia is characteristic of many human malignant neoplasm, 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 increasing $O_2$ delivery or facilitating metabolic adaptation to hypoxia. Increased level of HIF-$1{\alpha}$ has been reported in many human malignancies, but in non-small cell lung carcinoma the influence of HIF-$1{\alpha}$ on tumor biology, including neovascularization, is not still defined. In present study the relationship of HIF-$1{\alpha}$ expression on angiogenetic factors, relationship between the tumor proliferation and HIF-$1{\alpha}$ expression, interaction of HIF-$1{\alpha}$ expression and p53, and relationship between HIF-$1{\alpha}$ expression and clinico-pathological prognostic parameters were investigated. Material and Method: Archival tissue blocks recruited in this study were retrieved from fifty-nine patients with primary non-small cell lung carcinoma, who underwent pneumonectomy or lobectomy from 1997 to 1999. HIF-$1{\alpha}$, VEGF(vascular endothelial growth factor), and p53 protein expression and Ki-67 labeling index in tumor tissues were evaluated, using a standard avidin-biotin-peroxidase complex(ABC) immunohistochemistry. Relationship between the HIF-$1{\alpha}$ expression and VEGF, p53 overexpression and correlation between the HIF-$1{\alpha}$ expresseion and Ki-67 index were analyzed. Clinico-pathologic prognostic parameters were also analyzed. Result: HIF-$1{\alpha}$ expression in cancer cells was found in 24 of 59 cases of non-small cell lung carcinoma(40.7%). High HIF-$1{\alpha}$ expression was significantly associated with several pathological parameters, such as pathological TMN stage(p=0.004), pT stage(p=0.020), pN stage (p=0.029), and lymphovascular invasion(p=0.019). High HIF-$1{\alpha}$ expression was also significantly associated with VEGF immunoreactivity(p<0.001), and aberrant p53 expression(p=0.040). but was marginally associated with Ki-67 labeling index(p=0.092). The overall 5-year survival rate was 42.3%. The survival curve of patients with a high HIF-$1{\alpha}$ expression was worse than that of patients with low-expression(p=0.002). High HIF-$1{\alpha}$ expression was independent unfavorable factors with a marginal significance in multivariate analysis performed by Cox regression. Conclusion: It is suggested that high HIF-$1{\alpha}$ expression may be associated with intratumoral neovascularization possibly through HIF-VEGF pathway, and high HIF-$1{\alpha}$ expression could be associated with lymph node metastasis and post operative poor prognosis in patients with non-small cell lung carcinoma.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.331-336
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• 2010

In rapidly growing tumors, hypoxia commonly develops due to the imbalance between $O_2$ consumption and supply. Hypoxia Inducible Factor (HIF)-$1{\alpha}$ is a transcription factor responsible for tumor growth and angiogenesis in the hypoxic microenvironment; thus, its inhibition is regarded as a promising strategy for cancer therapy. Given that CamKII or PARP inhibitors are emerging anticancer agents, we investigated if they have the potential to be developed as new HIF-$1{\alpha}$-targeting drugs. When treating various cancer cells with the inhibitors, we found that a CamKII inhibitor, KN-62, effectively suppressed HIF-$1{\alpha}$ specifically in hepatoma cells. To examine the effect of KN-62 on HIF-$1{\alpha}$-driven gene expression, we analyzed the EPO-enhancer reporter activity and mRNA levels of HIF-$1{\alpha}$ downstream genes, such as EPO, LOX and CA9. Both the reporter activity and the mRNA expression were repressed by KN-62. We also found that KN-62 suppressed HIF-$1{\alpha}$ by impairing synthesis of HIF-$1{\alpha}$ protein. Based on these results, we propose that KN-62 is a candidate as a HIF-$1{\alpha}$-targeting anticancer agent.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.217-224
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• 2004

Purpose: It is well known that the radiosensitivity of tumor cells can be significantly reduced under hypoxic conditions. Hypoxia-inducible factor-1 $\alpha$ (HIF-1 $\alpha$) plays a pivotal role in the essential adaptive responses to hypoxia. Therefore this study investigated the relationship between HIF-1 $\alpha$ expression and radiosensitivity. M Mouse hepatoma cell line hepafcic7 and HIF-1 $\beta$-deficient mutant cell line hepa1C4 were used to analyze the role of HIF-1 a. on radiosensitivity. These cells were exposed for 6 h to desferrioxamine (DFX) before radiation. HIF-1$\alpha$. expression was examined by Western blot. Apoptosis was assessed by DNA fragmentation, propidium iodide staining, and apoptotic cell death detection ELISA kit. Radiation sensitivity was determined using MTT assay. The radiobioiogical parameters, surviving fractions at 2 Gy and 8 Gy, and mean inactivation dose (MID) from the linear-quadratic model were used to assess radiation sensitivity in the statistical analyses. Results: The expression of HIF-1 $\alpha$. was Increased, whereas apoptosis was decreased, by radiation In the presence of DFX In hepal cl c7, but not In hepal C4. The radlosensitivity of hepal C4 cells was not significantly affected by DFX treatment. The radiosensitivlty of hepal cl c7 cells was significantly decreased in the presence of DFX Conclusion: The expression of HIF-1 w by hypoxia-mimic agent DFX reduced apoptosls and radiosensitlvity in mouse hepatoma cell line hepafclc7. These results suggested that HIF-1 u could be Induced by irradiation in hypoxic ceils of tumor masses, and that this mlght Increase radioresistance in hypoxic cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3613-3618
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• 2013

Object: To detect expression of hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) and lysyl oxidase (LOX) in non-small cell lung cancer (NSCLC) and explore their roles in prognosis. Methods: The mRNA levels of HIF-$1{\alpha}$ and LOX were investigated by real-time reverse-transcriptase polymerase chain reaction in 40 cases of tumour and paired normal tissues. In addition, protein expression of HIF-$1{\alpha}$ and LOX was examined by immunohistochemistry in 82 cases of tumour and 45 paired normal tissues. The relationship between HIF-$1{\alpha}$ or LOX and clinicopathologic characteristics, as well as the correlation between HIF-$1{\alpha}$ and LOX, were also examined. Kaplan-Meier survival curves and the log-rank test were used to analyze progression-free survival. Results: HIF-$1{\alpha}$ or LOX mRNA levels in tumor tissues was significantly higher than those in paired normal tissues (p<0.01). Positive HIF-$1{\alpha}$ or LOX protein expression in tumor tissues was noted in 46/82 (56.1%) and 49/82 (59.8%) of the cases, respectively, being significantly higher than those in paired normal tissues (p<0.05). There was significant correlation between the expression of HIF-$1{\alpha}$ or LOX and tumor size, lymph node metastasis and pathological stage (p<0.05). The expression of HIF-$1{\alpha}$ and LOX had a significant inverse impact on survival of patients with NSCLC. Conclusion: HIF-$1{\alpha}$ and LOX may play a pivotal role in the development of NSCLC, and may act in synergy to promote the progression of NSCLC.

• Molecules and Cells
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• v.27 no.2
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• pp.243-250
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• 2009

Recent studies suggest a novel role of $HIF-1{\alpha}$ under nonhypoxic conditions, including antibacterial and antiviral innate immune responses. However, the identity of the pathogen-associated molecular pattern which triggers $HIF-1{\alpha}$ activation during the antiviral response remains to be identified. Here, we demonstrate that cellular administration of double-stranded nucleic acids, the molecular mimics of viral genomes, results in the induction of $HIF-1{\alpha}$ protein level as well as the increase in $HIF-1{\alpha}$ target gene expression. Whole-genome DNA microarray analysis revealed that double-stranded nucleic acid treatment triggers induction of a number of hypoxia-inducible genes, and induction of these genes are compromised upon siRNA-mediated $HIF-1{\alpha}$ knock-down. Interestingly, $HIF-1{\alpha}$ knock-down also resulted in down-regulation of a number of genes involved in antiviral innate immune responses. Our study demonstrates that $HIF-1{\alpha}$ activation upon nucleic acid-triggered antiviral innate immune responses plays an important role in regulation of genes involved in not only hypoxic response, but also immune response.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.2
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• pp.73-80
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• 2012

Objective: This study was undertaken to determine the effect of hypoxia inducible factor (HIF)-$1{\alpha}$ on the cell death, autophagy, and invasion of trophoblasts. Methods: To understand the effect of HIF-$1{\alpha}$, we inhibited HIF-$1{\alpha}$ using siRNA under normoxia and hypoxia conditions. Invasion assay and zymography were performed to determine changes in the invasion ability of HIF-$1{\alpha}$. Western blotting and immunofluorescence were performed to determine some of the signal events involved in apoptosis and autophagy. Results: There was no difference in cell death through the inhibition of HIF-$1{\alpha}$ expression by siRNA; however, the expression of LC3 and autophagosome formation increased. On the other hand, autophagy was increased, and the invasive ability of trophoblast cells decreased according to the inhibition of HIF-$1{\alpha}$ expression by siRNA. These experimental results mean that HIF-$1{\alpha}$ genes regulate the invasive ability of trophoblasts by increasing autophagy. Conclusion: This study contributes important data for understanding the mechanism of early pregnancy implantation and the invasive ability of trophoblasts by defining the relationship between the roles of HIF-$1{\alpha}$ and autophagy.

• BMB Reports
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• v.42 no.11
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• pp.737-742
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• 2009

Hypoxia-inducible factor-$1{\alpha}/{\beta}$ (HIF-$1{\alpha}/{\beta}$) is a heterodimeric transcriptional activator that mediates gene expression in response to hypoxia. HIF-$1{\alpha}$ has been noted as an effective therapeutic target for ischemic diseases such as myocardiac infarction, stroke and cancer. By using a yeast two-hybrid system and a random peptide library, we found a 16-mer peptide named F29 that directly interacts with the bHLH-PAS domain of HIF-$1{\alpha}$. We found that F29 facilitates the interaction of the HIF-$1{\alpha/\beta}$ heterodimer with its target DNA sequence, hypoxia-responsive element (HRE). The transient transfection of an F29-expressing plasmid increases the expression of both an HRE-driven luciferase gene and the endogenous HIF-1 target gene, vascular endothelial growth factor (VEGF). Taken together, we conclude that F29 increases the DNA-binding ability of HIF-$1{\alpha}$, leading to increased expression of its target gene VEGF. Our results suggest that F29 can be a lead compound that directly targets HIF-$1{\alpha}$ and increases its activity.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.2
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• pp.91-97
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• 2010

Epidermal keratinocytes overgrow in response to ultraviolet-B (UVB), which may be associated with skin photoaging and cancer development. Recently, we found that HIF-$1{\alpha}$ controls the keratinocyte cell cycle and thereby contributes to epidermal homeostasis. A further study demonstrated that HIF-$1{\alpha}$ is down-regulated by UVB and that this process is involved in UVB-induce skin hyperplasia. Therefore, we hypothesized that the forced expression of HIF-$1{\alpha}$ in keratinocytes would prevent UVB-induced keratinocyte overgrowth. Among several agents known to induce HIF-$1{\alpha}$, pyrithione-zinc (Py-Zn) overcame the UVB suppression of HIF-$1{\alpha}$ in cultured keratinocytes. Mechanistically, Py-Zn blocked the degradation of HIF-$1{\alpha}$ protein in keratinocytes, while it did not affect the synthesis of HIF-$1{\alpha}$. Moreover, the p21 cell cycle inhibitor was down-regulated after UVB exposure, but was robustly induced by Py-Zn. In mice repeatedly irradiated with UVB, the epidermis became hyperplastic and HIF-$1{\alpha}$ disappeared from nuclei of epidermal keratinocytes. However, a cream containing Py-Zn effectively prevented the skin thickening and up-regulated HIF-$1{\alpha}$ to the normal level. These results suggest that Py-Zn is a potential agent to prevent UVB-induced photoaging and skin cancer development. This work also provides insight into a molecular target for treatment of UVB-induced skin diseases.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.55-74
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• 2008

Previously, we have shown that hypoxia, through HIF-1, induces ligand-independent $ER{\alpha}$ activation and the physical interaction of HIF-1 and $ER{\alpha}$. However, the effect of hypoxia on the transactivation of $ER{\beta}$ is not yet known. In the present study, we found that hypoxia activated the $ER{\beta}$-mediated transcriptional response in the HEK 293 cell line, as determined by the transient expression of$ER{\beta}$ and ER-responsive reporter plasmids. The hypoxia-induced estrogen response element-mediated transcriptional response was dependent on $ER{\beta}$ expression and was inhibited by the ER antagonist ICI 182,780. Transactivation of $ER{\beta}$ was induced by the expression of HIF-$1{\alpha}$ under normoxic conditions, as determined by the expression of oxygen-independent stable GFP-HIF-$1{\alpha}$. HIF-$1{\alpha}$-induced $ER{\beta}$ transactivation was abolished by the inhibition of HIF-$1{\alpha}$ activation. This was determined by using chemical inhibitors for the MAPK pathway. In addition, HIF-$1{\alpha}$ interacted with $ER{\beta}$ in a mammalian-two hybrid assay. We conclude that hypoxia activates $ER{\beta}$ in a ligand-independent manner, possibly through the interaction of HIF-$1{\alpha}$ and $ER{\beta}$.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8251-8257
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• 2014

Apoptosis is one of main types of neural cell death and is reversible and is a major target of therapeutic interventions. However, detailed apoptotic cascades still need to be recognized. In present study, we determined the promotion of HIF-$1{\alpha}$ and survivin in brain samples of a mouse model of hypoxic-ischemia and in neuroblastoma SH-SY5Y cells post hypoxia treatment. Then gain-of-function and loss-of-function strategies were adopted to manipulate the HIF-$1{\alpha}$ in SH-SY5Y cells, and hypoxia-induced survivin upregulation and cell apoptosis were determined. Results demonstrated that the HIF-$1{\alpha}$ and survivin were significantly promoted in a mouse model of hypoxic-ischemia or in SH-SY5Y cells post hypoxia in vitro. Manually upregulated HIF-$1{\alpha}$ could promote the hypoxia-induced survivin upregulation and improve the hypoxia-induced SH-SY5Y cell apoptosis. On the other hand, the HIF-$1{\alpha}$ knockdown by RNAi reduced the hypoxia-induced survivin upregulation and cell apoptosis. Therefore, the present study confirmed the protective role of HIF-$1{\alpha}$ and survivin in the hypoxia-induced SH-SY5Y cell apoptosis, and the survivin upregulation by hypoxia is HIF-$1{\alpha}$-dependent. Promotion of HIF-$1{\alpha}$ and survivin might be a valuable stragegy for therapeutic intervention for hypoxic-ischemic encephalopathy.