• BMB Reports
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• v.32 no.2
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• pp.112-118
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• 1999

The presence of hypoxic cells in solid tumors has long been considered a problem in cancer treatment such as in radiation therapy or treatment with some anticancer drugs. It has been suggested that hypoxic cells are involved in the development of a more aggressive phenotype and contribute to metastasis. In this study, as an attempt to understand how tumor cells adapt to hypoxic stress, we investigated the regulation of the hypoxia-induced expression of proteins that control essential processes of tumor cell survival and angiogenesis. We first examined whether hypoxia induces stress protein gene expression of murine solid tumor RIF cells. We also examined hypoxia-induced changes in angiogenic gene expression in these cells. Finally, we investigated the association of the elevated levels of stress proteins with the regulation of hypoxia-induced angiogenic gene expression. Results demonstrated that hypoxia induced the expression of the erythropoietin (EPO) gene and at least two major members of stress proteins, heat shock protein 70 (HSP70) and 25 (HSP25) in RIF tumor cells. Evidence that the expression of EPO gene was greatly potentiated in TR cells suggested that the elevated levels of HSPs may play an important role in the regulation of the hypoxia-induced EPO gene expression. One of the RIF variant cell lines, TR, displays elevated levels of HSPs constitutively. Taken together, our results suggest that a hypoxic tumor microenvironment may promote the survival and malignant progression of the tumor cells by temporarily increasing the level of stress proteins and expressing angiogenic genes. We suspect that stress proteins may be associated with the increase of the angiogenic potential of tumor cells under hypoxia.

• Journal of Gastric Cancer
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• v.17 no.1
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• pp.1-10
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• 2017

Gastric cancer (GC) has high mortality owing to its aggressive nature. Tumor angiogenesis plays an essential role in the growth, invasion, and metastatic spread of GC. The aim of this work was to review the angiogenic biomarkers related to the behavior of GC, documented in the literature. A search of the PubMed database was conducted with the MeSH terms: "Stomach neoplasms/blood [MeSH] or stomach neoplasms/blood supply [MeSH] and angiogenic proteins/blood [Major]". A total of 30 articles were initially collected, and 4 were subsequently excluded. Among the 26 articles collected, 16 examined the role of vascular endothelial growth factor (VEGF), 4 studied endostatin, 3 investigated angiopoietin (Ang)-2, 2 studied the Ang-like protein 2 (ANGTPL2), and 1 each examined interleukin (IL)-12, IL-8, and hypoxia inducible factor. Regarding VEGF, 6 articles concluded that the protein was related to lymph node metastasis or distant metastases. Five articles concluded that VEGF levels were elevated in the presence of GC and decreased following tumor regression, suggesting that VEGF levels could be a predictor of recurrence. Four articles concluded that high VEGF levels were correlated with poor prognosis and lower survival rates. Ang-2 and ANGTPL2 were elevated in GC and associated with more aggressive disease. Endostatin was associated with intestinal GC. VEGF is the most extensively studied angiogenic factor. It is associated with the presence of neoplastic disease and lymph node metastasis. It appears to be a good biomarker for disease progression and remission, but not for diagnosis. The data regarding other biomarkers are inconclusive.

• 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.1-12
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• 2006

Objective : Angiogenesis is an essential process for metastasis of solid tumors and Psoriasis. Lots of Researches for anti-angiogenic effect to angiogenic factors have been carried out in the world. So this experiment was carried out for whether Lacca Sinica Exsiccata(LSE) extracts have an anti-angiogenic effect for angiogenic factors. Methods: To investigate the roles of the LSE extracts, we performed MIS assay, western blots using HaCaT cells and HepG2 cells. And then, HaCaT cells were treated with 10, 50, 100, 250, $500{\mu}g/ml$ LSE extracts. After 4hrs, HaCaT cells were theated with IGF-II protein for 1hr. HepG2 cells were treated with 1, 10, 25, 50, 100, 200 ${\mu}g/ml$ LSE extracts. After 4hrs, HepG2 cells were theated with $CoCl_2$ for 24hrs Results: 1. In $50{\mu}g/ml$ and $100{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to $HIF-1{\alpha}$ activation which was induced by IGF-II in HaCaT cells. 2. In $50{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to $HIF-1{\alpha}$ activation which was induced by $CoCl_2$ in HepG2 cells. 3. In $25{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to VEGF activation which was induced by $CoCl_2$ in HepG2 cells. Conclusion: The above-mentioned results proved that LSE extracts reduced $HIF-1{\alpha}$ protein level in the HaCaT cells and HepG2 cells. These results suggest that inhibition of HaCaT cell and HepG2 cell proliferation by LSE extracts contributes to the anti-angiogenic activities on the keratinocytes and hepatocellular carcinoma.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.1
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• pp.10-23
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• 2007

Hallmarks of clinical behaviors of adenoid cystic carcinoma(ACC) of salivary glands are the delayed onset of vascular metastasis and poor responses to classical chemotherapeutic agents. Poor prognoses from salivary ACC are caused by lung metastases that are resistant to conventional therapy. Therefore, cellular and molecular characteristics that influence the dissemination of metastatic cells are important for the design of more effective treatment of salivary ACC. Tumor angiogenesis has been known to be essential for the distant metastasis of malignant cells. So, we determined expressions of angiogenic proteins in benign (pleomorphic adenoma) and malignant (ACC, mucoepidermoid carcinoma) tumors of salivary glands and compared each other and to those in oral squamous cell carcinoma. Using surgical specimens, we performed immunohistochemical assays with anti-vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), phosphorylated VEGFR-2 (pVEGFR-2), matrix metalloproteinase (MMP)-9, and interleukin (IL)-8 antibodies. Most angiogenic factors were overexpressed in malignant salivary tumors than in pleomorphic adenoma which is benign nature. Moreover, ACC demonstrated more expression of VEGFR-2 than that of squamous cell carcinoma which used as control. Conclusively, these data show those angiogenic factors produced by salivary gland tumors may affect the propagation and metastasis of malignant cells of salivary tumors, and could be used as biomarkers for the malignant transformation of salivary gland tumors. Prospectively, although further studies will be needed, these biomarkers related to angiogenesis can be molecular targets for the therapy of salivary ACC, which has propensity for delayed vascular metastasis.

• BMB Reports
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• v.55 no.4
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• pp.175-180
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• 2022

Peptides are gaining substantial attention as therapeutics for human diseases. However, they have limitations such as low bioavailability and poor pharmacokinetics. Periostin, a matricellular protein, can stimulate the repair of ischemic tissues by promoting angiogenesis. We have previously reported that a novel angiogenic peptide (amino acids 142-151) is responsible for the pro-angiogenic activity of periostin. To improve the in vivo delivery efficiency of periostin peptide (PP), we used proteins self-assembled into a hollow cage-like structure as a drug delivery nanoplatform in the present study. The periostin peptide was genetically inserted into lumazine synthase (isolated from Aquifex aeolicus) consisting of 60 identical subunits with an icosahedral capsid architecture. The periostin peptide-bearing lumazine synthase protein cage nanoparticle with 60 periostin peptides multivalently displayed was expressed in Escherichia coli and purified to homogeneity. Next, we examined angiogenic activities of this periostin peptide-bearing lumazine synthase protein cage nanoparticle. AaLS-periostin peptide (AaLS-PP), but not AaLS, promoted migration, proliferation, and tube formation of human endothelial colony-forming cells in vitro. Intramuscular injection of PP and AaLS-PP increased blood perfusion and attenuated severe limb loss in the ischemic hindlimb. However, AaLS did not increase blood perfusion or alleviate tissue necrosis. Moreover, in vivo administration of AaLS-PP, but not AaLS, stimulated angiogenesis in the ischemic hindlimb. These results suggest that AaLS is a highly useful nanoplatform for delivering pro-angiogenic peptides such as PP.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1823-1825
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• 2005

Angiogenesis is tightly regulated by a variety of angiogenic activators and inhibitors. Disruption of the balanced angiogenesis leads to the progress of diseases such as cancer, rheumatoid arthritis, and diabetic blindness. Even though a number of proteins involved in angiogenesis have been identified so far, more protein factors remain to be identified due to complexity of the process. Here I report that pituitary tumor-transforming gene (PTTG) induces migration and tube formation of human umbilical vein endothelial cells (HUVECs). High levels of both vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are detected in conditioned medium obtained from cells transfected with PTTG expression plasmid. Taken together, these results suggest that PTTG is an angiogenic factor that induces production of both VEGF and bFGF.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.477-486
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• 2017

Background: Our previous studies have demonstrated that ginsenoside-Rg1 can promote angiogenesis in vitro and in vivo through activation of the glucocorticoid receptor (GR). Furthermore, microRNA (miRNA) expression profiling has shown that Rg1 can modulate the expression of a subset of miRNAs to induce angiogenesis. Moreover, Rb1 was shown to be antiangiogenic through activation of a different pathway. These studies highlight the important functions of miRNAs on ginseng-regulated physiological processes. The aim of this study was to determine the angiogenic properties of Korean Red Ginseng extract (KGE). Methods and Results: Combining in vitro and in vivo data, KGE at $500{\mu}g/mL$ was found to induce angiogenesis. According to the miRNA sequencing, 484 differentially expressed miRNAs were found to be affected by KGE. Among them, angiogenic-related miRNAs; miR-15b, -23a, -214, and -377 were suppressed by KGE. Meanwhile, their corresponding angiogenic proteins were stimulated, including vascular endothelial growth factor, vascular endothelial growth factor receptor-2, endothelial nitric oxide synthase, and MET transmembrane tyrosine kinase. The miRNAs-regulated signaling pathways of KGE were then found by Cignal 45-Pathway Reporter Array, proving that KGE could activate GR. Conclusion: KGE was found capable of inducing angiogenesis both in vivo and in vitro models through activating GR. This study provides a valuable insight into the angiogenic mechanisms depicted by KGE in relation to specific miRNAs.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.59-63
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• 2008

Rapid production of therapeutic proteins such as angiostatin and endostatin angiogenic inhibititors has been highly demanded for cancer treatment. In this regard, recombinant human angiostatin and endostatin were successfully expressed as soluble forms by maltose binding protein (MBP)-mediated fusion expression in Escherichia coli. PCR amplified, angiostatin and endostatin genes from human placenta cDNA library were inserted into an expression vector pMAL-c2e to construct prokaryotic expression vectors, pMAL-c2e/AS and pMAL-c2e/ES, respectively. Recombinant angiostatin and endostatin were efficiently expressed in E. coli origami (DE3) after IPTG induction and protein expression were confirmed by SDS-PAGE analyses. The expressed recombinant proteins were purified near homogenity using an amylose affinty column chromatography. In contrast that previous E. coli expressions were all insoluble, our results first time demonstrated that MBP fused human angiostatin and endostatin were soluble in E. coli.

• BMB Reports
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• v.31 no.5
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• pp.427-431
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• 1998

In the previous report (Choi et al., 1997), the angiogenin binding peptides identified from a phage-peptide library were analyzed by using the fusion proteins composed of the Escherichia coli maltose binding protein and its corresponding peptides. However, it was difficult to obtain a sufficient amount of the fusion proteins required for further analysis because of the low expression level. We now report a high level expression of the fusion protein and analysis of its anti-angiogenin activity. The use of strong T7 promoter and removal of signal sequence allowed about a 20-fold increase in the expression efficiency of the fusion protein. We were able to obtain about 10 mg of purified fusion protein from one liter of culture. The purified fusion protein showed angiogenin-specific affinity and inhibited the binding of biotinylated actin to human angiogenin at $IC_{50}$ of 0.6 mM. Its anti-angiogenin activity was also revealed by the chorioallantoic membrane assay.

• BMB Reports
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• v.42 no.6
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• pp.344-349
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• 2009

Angiogenesis is crucial for solid tumor growth. By secreting angiogenic factors, tumor cells induce angiogenesis. However, targeting these angiogenic factors for cancer therapy is not always successful, suggesting that other factors may be involved in tumor angiogenesis. This work shows that 25 protein spots were differentially expressed by two-dimensional gel electrophoretic analysis when HepG2 cells induced endothelial cell differentiation to tube in vitro, and most of them were upregulated. Twenty-one proteins were identified with MALDITOF-MS, and the other four were identified by LTQ-MS/MS. Keratins were identified as one class of these upregulated proteins. Further study indicated that the expression of keratin 17 in cultured endothelial cells is likely microenvironment regulated, because its expression can be induced by HepG2 cells and bFGF as well as serum in culture media. Increased expression of keratins in endothelial cells, such as keratin 17, may contribute to the angiogenesis induced by HepG2 cells.