• 생명과학회지
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• 제28권12호
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• pp.1469-1476
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• 2018

Warburg 효과의 발생은 고형암에서 화학적 항암제의 내성을 발생시킨다. 따라서 호기성 해당과정과 같은 에너지 대사과정은 암 치료의 중요한 표적으로 알려져 있다. Pyruvate dehydrogenase kinase (PDK) 활성 억제물질로 알려진 dichloroacetate (DCA)는 많은 암세포에서 포도당의 호기성 해당과정을 산화적인산화 과정으로 전환시킬 수 있음이 보고되었다. 이 연구는 치료가 매우 어렵다고 알려진 인간 역분화 갑상선 암세포주인 8505C의 성장에 미치는 DCA효과를 조사하였다. DCA는 정상 갑상선 세포주의 성장에는 영향을 주지 않은 반면 8505C 세포주의 성장을 특이적으로 저해하였다. DCA의 처리에 의해 8505C 세포주는 $HIF1{\alpha}$, PDK1, Bcl-2와 같은 항-세포자살 관련 단백질들의 발현이 감소하고, Bax와 p21과 같은 세포자살 유도 단백질과 세포주기 억제 단백질의 증가로 인하여 세포주기 정지와 세포자살 유도에 의해 성장이 억제되었다. 이런 세포의 변화는 DCA 처리에 의한 활성산소족의 생산이 증가하고, 포도당 대사가 호기성 해당과정에서 산화적인산화 과정으로 전환되었기 때문이란 것을 확인하였다. 흥미롭게도, DCA는 포도당 대사과정의 변화뿐만 아니라 sodium/iodine symporter (NIS)의 발현양도 증가시킨다는 것을 확인하였다. 이 연구의 결과로 PDK 활성 저해제는 치료하기 힘든 역분화 갑상선 암 치료제로 이용할 수 있고, 또한 역분화 갑상선 암에 대한 방사능 치료의 효능을 높일 수 있을 것으로 기대된다.

• Molecules and Cells
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• 제37권6호
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• pp.487-496
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• 2014

Angiotensinogen (AGT), the precursor of angiotensin I, is known to be involved in tumor angiogenesis and associated with the pathogenesis of coronary atherosclerosis. This study was undertaken to determine the role played by AGT in endothelial progenitor cells (EPCs) in tumor progression and metastasis. It was found that the number of EPC colonies formed by AGT heterozygous knockout ($AGT^{+/-}$) cells was less than that formed by wild-type (WT) cells, and that the migration and tube formation abilities of $AGT^{+/-}$ EPCs were significantly lower than those of WT EPCs. In addition, the gene expressions of vascular endothelial growth factor (VEGF), Flk1, angiopoietin (Ang)-1, Ang-2, Tie-2, stromal derived factor (SDF)-1, C-X-C chemokine receptor type 4 (CXCR4), and of endothelial nitric oxide synthase (eNOS) were suppressed in $AGT^{+/-}$ EPCs. Furthermore, the expressions of hypoxia-inducible factor (HIF)-$1{\alpha}$and $-2{\alpha}$ were downregulated in $AGT^{+/-}$ early EPCs under hypoxic conditions, suggesting a blunting of response to hypoxia. Moreover, the activation of Akt/eNOS signaling pathways induced by VEGF, epithelial growth factor (EGF), or SDF-$1{\alpha}$ were suppressed in $AGT^{+/-}$ EPCs. In $AGT^{+/-}$ mice, the incorporation of EPCs into the tumor vasculature was significantly reduced, and lung tumor growth and melanoma metastasis were attenuated. In conclusion, AGT is required for hypoxia-induced vasculogenesis.

• Mass Spectrometry Letters
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• 제9권2호
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• pp.61-65
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• 2018

KPLA-012, a benzopyranyl 1,2,3-triazole compound, is considered a potent $HIF-1{\alpha}$ inhibitor based on the chemical library screening, and is known to exhibit anti-angiogenetic and anti-tumor progressive effects. The aim of this study was to investigate the pharmacokinetic properties of KPLA-012 in ICR mice and to investigate in vitro characteristics including the intestinal absorption, distribution, metabolism, and excretion of KPLA-012. The oral bioavailability of KPLA-012 was 33.3% in mice. The pharmacokinetics of KPLA-012 changed in a metabolism-dependent manner, which was evident by the low recovery of parent KPLA-012 from urine and feces and metabolic instability in the liver microsomes. However, KPLA-012 exhibited moderate permeability in Caco-2 cells ($3.1{\times}10^{-6}cm/s$) and the metabolic stability increased in humans compared to that in mice (% remaining after 1 h; 47.4% in humans vs 14.8% in mice). Overall, the results suggest that KPLA-012 might have more effective pharmacokinetic properties in humans than in mice although further studies on its metabolism are necessary.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.793-801
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• 2018

BACKGROUND: The aim of this study was to evaluate the combined effect of low-level laser treatment (LLLT) and recombinant human bone morphological protein-2 (rhBMP-2) applied to hypoxic-cultured MC3T3-E1 osteoblastic cells and to determine possible signaling pathways underlying differentiation and mineralization of osteoblasts under hypoxia. METHODS: MC3T3-E1 cells were cultured under 1% oxygen tension for 72 h. Cell cultures were divided into four groups: normoxia control, low-level laser (LLL) alone, rhBMP-2 combined with LLLT, and rhBMP-2 under hypoxia. Laser irradiation was applied at 0, 24, and 48 h. Cells were treated with rhBMP-2 at 50 ng/mL. Alkaline phosphatase activity was measured at 3, 7, and 14 days to evaluate osteoblastic differentiation. Cell mineralization was determined with Alizarin red S staining at 7 and 14 days. Western blot assays were performed to evaluate whether p38/protein kinase D (PKD) signaling was involved. RESULTS: The results indicate that LLLT and rhBMP-2 synergistically increased alkaline phosphatase (ALP) activity and mineralization. Western blot analyses showed that expression of type I collagen, runt-related transcription factor 2 (RUNX2), and Osterix (Osx), increased and expression of hypoxia-inducible factor 1-alpha ($HIF-1{\alpha}$), decreased more in the LLLT and rhBMP-2 combined group than in the rhBMP-2 or LLL alone groups. Moreover, LLLT and rhBMP-2 stimulated p38 phosphorylation and rhBMP-2 and LLLT increased Prkd1 phosphorylation. CONCLUSION: Combined treatment with rhBMP-2 and LLL induced differentiation and mineralization of hypoxic-cultured MC3T3-E1 osteoblasts by activating p38/PKD signaling in vitro.

• BMB Reports
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• 제51권4호
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• pp.174-181
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• 2018

A number of genes have been therapeutically targeted to relieve cancer, but cancer relapse is still a growing issue. The concept that the surrounding tumor environment is critical for the progression of cancer may foster an answer to the issue of cancer malignancy. Runt domain transcription factors (RUNX1, 2, and 3) are evolutionarily conserved and have been intensively studied for their roles in normal development and pathological conditions. During tumor growth, a hypoxic microenvironment and infiltration of the tumor by immune cells are common phenomena. In this review, we briefly introduce the consequences of hypoxia and immune cell infiltration into the tumor microenvironment with a focus on RUNX3 as a critical regulator. Furthermore, based on our current knowledge of the functional role of RUNX3 in hypoxia and immune cell maintenance, a probable therapeutic intervention is suggested for the effective management of tumor growth and malignancy.

• Molecules and Cells
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• 제39권12호
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• pp.898-908
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• 2016

Despite recent groundbreaking advances in multiple myeloma (MM) treatment, most MM patients ultimately experience relapse, and the relapse biology is not entirely understood. To define altered gene expression in MM relapse, gene expression profiles were examined and compared among 16 MM patients grouped by 12 months progression-free survival (PFS) after autologous stem cell transplantation. To maximize the difference between prognostic groups, patients at each end of the PFS spectrum (the four with the shortest PFS and four with the longest PFS) were chosen for additional analyses. We discovered that integrin-${\alpha}8$ (ITGA8) is highly expressed in MM patients with early relapse. The integrin family is well known to be involved in MM progression; however, the role of integrin-${\alpha}8$ is largely unknown. We functionally overexpressed integrin-${\alpha}8$ in MM cell lines, and surprisingly, stemness features including $HIF1{\alpha}$, VEGF, OCT4, and Nanog, as well as epithelial mesenchymal transition (EMT)-related phenotypes, including N-cadherin, Slug, Snail and CXCR4, were induced. These, consequently, enhanced migration and invasion abilities, which are crucial to MM pathogenesis. Moreover, the gain of integrin-${\alpha}8$ expression mediated drug resistance against melphalan and bortezomib, which are the main therapeutic agents in MM. The cBioPortal genomic database revealed that ITGA8 have significant tendency to co-occur with PDGFRA and PDGFRB and their mRNA expression were up-regulated in ITGA8 overexpressed MM cells. In summary, integrin-${\alpha}8$, which was up-regulated in MM of early relapse, mediates EMT-like phenotype, enhancing migration and invasion; therefore, it could serve as a potential marker of MM relapse and be a new therapeutic target.

• Radiation Oncology Journal
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• 제34권3호
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• pp.230-238
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• 2016

Purpose: Hypoxia can impair the therapeutic efficacy of radiotherapy (RT). Therefore, a new strategy is necessary for enhancing the response to RT. In this study, we investigated whether the combination of nanoparticles and RT is effective in eliminating the radioresistance of hypoxic tumors. Materials and Methods: Gold nanoparticles (GNPs) consisting of a silica core with a gold shell were used. CT26 colon cancer mouse model was developed to study whether the combination of RT and GNPs reduced hypoxia-induced radioresistance. Hypoxia inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) was used as a hypoxia marker. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were conducted to evaluate cell death. Results: Hypoxic tumor cells had an impaired response to RT. GNPs combined with RT enhanced anti-tumor effect in hypoxic tumor compared with RT alone. The combination of GNPs and RT decreased tumor cell viability compare to RT alone in vitro. Under hypoxia, tumors treated with GNPs + RT showed a higher response than that shown by tumors treated with RT alone. When a reactive oxygen species (ROS) scavenger was added, the enhanced antitumor effect of GNPs + RT was diminished. Conclusion: In the present study, hypoxic tumors treated with GNPs + RT showed favorable responses, which might be attributable to the ROS production induced by GNPs + RT. Taken together, GNPs combined with RT seems to be potential modality for enhancing the response to RT in hypoxic tumors.

• Korean Chemical Engineering Research
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• 제51권6호
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• pp.727-732
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• 2013

본 연구는 역오팔 지지체를 이용하여 인간지방유래 줄기세포의 연골 분화를 촉진하는 내용을 담고 있다. 비 다공성 구조를 가진 지지체에서 세포를 분화 시도하였을 경우 분화가 잘 촉진되지 않는 것에 비해 200 nm 정도의 균일한 구멍을 가지는 poly(D,L-lactide-co-glycolide)로 구성된 역오팔 지지체는 그 다공성 구조로 인하여 지지체의 내부까지 산소와 유기물의 수송을 가능하게 하여 지지체 내에서 어떤 유전적, 약물적 처리 없이 인간지방유래 줄기세포가 분화가 잘 되게 하는 것을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6319-6325
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• 2012

We previously found cytotoxic effects of tomato leaf extract (TLE) on the MCF-7 breast cancer cell line. The aim of this study was to ascertain the molecular mechanisms associated with the usage of TLE as an anticancer agent by microarray analysis using mRNA from MCF-7 breast cancer cells after treatment with TLE for 1 hr and 48 hrs. Approximately 991 genes out of the 30,000 genes in the human genome were significantly (p<0.05) changed after the treatment. Within this gene set, 88 were significantly changed between the TLE treated cells and the untreated MCF-7 cells (control cells) with a cut-off fold change >2.00. In order to focus on genes that were involved in cancer cell growth, only twenty-nine genes were selected, either down-regulated or up-regulated after treatment with TLE. Microarray assay results were confirmed by analyzing 10 of the most up and down regulated genes related to cancer cells progression using real-time PCR. Treatment with TLE induced significant up-regulation in the expression of the CRYAB, PIM1, BTG1, CYR61, HIF1-${\alpha}$ and CEBP-${\beta}$ genes after 1 hr and 48 hrs, whereas the TXNIP and THBS1 genes were up-regulated after 1 hr of treatment but down-regulated after 48 hrs. In addition both the HMG1L1 and HIST2H3D genes were down-regulated after 1 hr and 48 hrs of treatment. These results demonstrate the potent activity of TLE as an anticancer agent.

• Biomolecules & Therapeutics
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• 제23권1호
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• pp.19-25
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• 2015

Vascular endothelial growth factor (VEGF) is an important regulator of neovascularization. Hypoxia inducible nitric oxide (NO) enhanced the expression of VEGF and thymosin beta-4 ($T{\beta}4$), actin sequestering protein. Here, we investigated whether NO-mediated VEGF expression could be regulated by $T{\beta}4$ expression in HeLa cervical cancer cells. Hypoxia inducible NO production and VEGF expression were reduced by small interference (si) RNA of $T{\beta}4$. Hypoxia response element (HRE)-luciferase activity and VEGF expression were increased by the treatment with N-(${\beta}$-D-Glucopyranosyl)-N2-acetyl-S-nitroso-D, L-penicillaminamide (SNAP-1), to generate NO, which was inhibited by the inhibition of $T{\beta}4$ expression with $T{\beta}4$-siRNA. In hypoxic condition, HRE-luciferase activity and VEGF expression were inhibited by the treatment with $N^G$-monomethyl-L-arginine (L-NMMA), an inhibitor to nitric oxide synthase (NOS), which is accompanied with a decrease in $T{\beta}4$ expression. VEGF expression inhibited by L-NMMA treatment was restored by the transfection with pCMV-$T{\beta}4$ plasmids for $T{\beta}4$ overexpression. Taken together, these results suggest that $T{\beta}4$ could be a regulator for the expression of VEGF via the maintenance of NOS activity.