• Biomolecules & Therapeutics
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• 제25권6호
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• pp.625-633
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• 2017

Sphingosylphosphorylcholine (SPC) is one of the bioactive phospholipids that has many cellular functions such as cell migration, adhesion, proliferation, angiogenesis, and $Ca^{2+}$ signaling. Recent studies have reported that SPC induces invasion of breast cancer cells via matrix metalloproteinase-3 (MMP-3) secretion leading to WNT activation. Thrombospondin-1 (TSP-1) is a matricellular and calcium-binding protein that binds to a wide variety of integrin and non-integrin cell surface receptors. It regulates cell proliferation, migration, and apoptosis in inflammation, angiogenesis and neoplasia. TSP-1 promotes aggressive phenotype via epithelial mesenchymal transition (EMT). The relationship between SPC and TSP-1 is unclear. We found SPC induced EMT leading to mesenchymal morphology, decrease of E-cadherin expression and increases of N-cadherin and vimentin. SPC induced secretion of thrombospondin-1 (TSP-1) during SPC-induced EMT of various breast cancer cells. Gene silencing of TSP-1 suppressed SPC-induced EMT as well as migration and invasion of MCF10A cells. An extracellular signal-regulated kinase inhibitor, PD98059, significantly suppressed the secretion of TSP-1, expressions of N-cadherin and vimentin, and decrease of E-cadherin in MCF10A cells. ERK2 siRNA suppressed TSP-1 secretion and EMT. From online PROGgene V2, relapse free survival is low in patients having high TSP-1 expressed breast cancer. Taken together, we found that SPC induced EMT and TSP-1 secretion via ERK2 signaling pathway. These results suggests that SPC-induced TSP-1 might be a new target for suppression of metastasis of breast cancer cells.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 KSOT/KEMS Fall Annual Meeting
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• pp.115-115
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• 2004

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2619-2623
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• 2014

Aim: To investigate signaling pathways for reversal of EGF-mediated multi-drug resistance (MDR) in hepatocellular carcinoma (HCC) models. Materials and Methods: HCC MDR cell strain HepG2/adriamycin (ADM) and SMMC7721/ADM models were established using a method of exposure to medium with ADM between low and high concentration with gradually increasing concentration. Drug sensitivity and reversal of multi-drug resistance by EGF were determined and the cell cycle distribution and apoptosis were analyzed by flow cytometry. Phosphorylation of ERK1, ERK2, ERK5 and expression of Bim were detected by Western blotting. Results: The results showed that HepG2/ADM and SMMC7721/ADM cells were resistant not only to ADM, but also to multiple anticancer drugs. When used alone, EGF had no anti-tumor activity in HepG2/ADM and SMMC7721/ADM cells in vitro, while it increased the cytotoxicity of ADM. EGF induced cell apoptosis and G0/G1 phase cell cycle arrest in HepG2/ADM And SMMC7721/ADM cells, while enhancing activity of p-ERKs and up-regulated expression of BimEL. Conclusions: EGF might enhance the chemosensitivity of HepG2/ADM and SMMC7721/ADM cells via up-regulating p-ERKs and BimEL protein.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.595-603
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• 2016

Ribosomal S6 kinase is a family of serine/threonine protein kinases involved in the regulation of cell viability. There are two subfamilies of ribosomal s6 kinase, (p90rsk, p70rsk). Especially, p90rsk is known to be an important downstream kinase of p44/42 MAPK. We investigated the role of p90rsk on ethanol-induced cell proliferation of HepG2 cells. HepG2 cells were treated with 10~50 mM of ethanol with or without ERK and p90rsk inhibitors. Cell viability was measured by MTT assay. The expression of pERK1, NHE1 was measured by Western blots. The phosphorylation of p90rsk was measured by ELISA kits. The expression of Bcl-2 was measured by qRT-PCR. When the cells were treated with 10~30 mM of ethanol for 24 hour, it showed significant increase in cell viability versus control group. Besides, 10~30 mM of ethanol induced increased expression of pERK1, p-p90rsk, NHE1 and Bcl-2. Moreover treatment of p90rsk inhibitor attenuated the ethanol-induced increase in cell viability and NHE1 and Bcl-2 expression. In summary, these results suggest that p90rsk, a downstream kinase of ERK, plays a stimulatory role on ethanol-induced hepatocellular carcinoma progression by activating anti-apoptotic factor Bcl-2 and NHE1 known to regulate cell survival.

• IMMUNE NETWORK
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• 제5권4호
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• pp.193-198
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• 2005

Background: Protease-activated receptor 2 (PAR2) belongs to a family of G protein coupled receptors activated by proteolytic cleavage. Trypsin-like serine proteases interact with PAR2 expressed by a variety of tissues and immune cells. The aim of our study was to investigate whether PAR2 stimulation can lead to the activation of human mac rophages. Methods: PAR2-mediated proliferation of human macrophage cell line THP-1 was measured with MTT assay. We also examined the extracellular regulated kinase (ERK) phosphorylation and cytokine production induced by trypsin and PAR2-agonist using western blot and enzyme-linked immunosorbent assay (ELISA), respectively. Results: Treatment of trypsin or PAR2-activating peptide increased cell proliferation in a dose-dependent manner, and induced the activation of ERK1/2 in THP-1 cells. In addition, trypsin-induced cell proliferation was inhibited by pretreatment of an ERK inhibitor (pD98059) or trypsin inhibitor (SBTI). Moreover, PAR2 activation by trypsin increased the secretion of TNF-${\alpha}$ in THP-1 cells. Conclusion: There results suggest that P AR2 activation by trypsin-like serine proteases can induce cell proliferation through the activation of ERK in human macrophage and that PAR2 may playa crucial role in the cell proliferation and cytokine secretion induced by trypsin-like serine proteases.

• 대한임상검사과학회지
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• 제51권2호
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• pp.245-251
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• 2019

본 연구는 2-methoxy-1,4-naphthoquinone (MQ)이 Monocyte chemoattractant protein-1 (MCP-1)에 의해 유도된 단구 유주에 미치는 효과를 알아보고자 진행되었다. 단구의 유주(migration) 현상은 신체 방어와 면역반응에 중요한 현상이다. MQ는 아시아권 국가에서 다양한 질병과 통증 치료에 민간요법으로 오랫동안 사용되었던 봉선화(Impatiens balsamina) 잎으로부터 추출한 주요 성분이다. 단구 세포주 THP-1를 이용하여 실험을 진행하였으며, MQ의 세포독성, MCP-1에 의해 유도된 유주 현상에 미치는 영향을 transwell system을 이용하여 확인하였다. MQ 작용기전을 이해하기 위해 cAMP 발현 및 Erk1/2 인산화를 각각 ELISA, Western-blot 기법을 통해 분석하였다. MQ의 단구 세포주 THP-1에 대한 MQ의 세포독성은 $10{\mu}M$ 농도에서 나타나기 시작했으며, $100{\mu}M$ 농도에서 약 50% 가량의 세포독성을 확인했다. 염증성 화학주성 인자 MCP-1에 의해 유도된 단핵구 세포주 THP-1의 유주현상은 MQ 처리 후 농도증가에 비례하여 증가하였으며, $0.1{\mu}M$ 농도의 MQ를 처리했을 때 가장 높은 증가를 보였다. MCP-1 단독 처리 시 감소하는 cAMP 의 배양액 내 발현은 MQ 동시 처리 시 더욱 감소하였고, 유주현상과 마찬가지로 $0.1{\mu}M$ 농도에서 가장 감소하였다. MCP-1의 수용체인 C-C motif chemokine receptor 2 (CCR2) 신호전달 과정에 관여하는 주요 신호전달 단백질인 Erk1/2의 인산화도 $0.1{\mu}M$ MQ 동시 처리 시 증가하였다. 이상의 결과를 통해 MQ가 MCP-1에 의해 유도되는 THP-1 세포주의 유주현상을 증가시키며, 연관된 cAMP 발현을 감소, Erk1/2 인산화는 증가시키는 경향을 확인하였다.

• Journal of Ginseng Research
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• 제42권3호
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• pp.288-297
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• 2018

Background: The incidence of colorectal cancer (CRC) is increasing, with metastasis of newly diagnosed CRC reported in a large proportion of patients. However, the effect of Korean Red Ginseng extracts (KRGE) on epithelial to mesenchymal transition (EMT) in CRC is unknown. Therefore, we examined the mechanisms by which KRGE regulates EMT of CRC in hypoxic conditions. Methods: Human CRC cell lines HT29 and HCT116 were incubated under hypoxic (1% oxygen) and normoxic (21% oxygen) conditions. Western blot analysis and real-time PCR were used to evaluate the expression of EMT markers in the presence of KRGE. Furthermore, we performed scratched wound healing, transwell migration, and invasion assays to monitor whether KRGE affects migratory and invasive abilities of CRC cells under hypoxic conditions. Results: KRGE-treated HT29 and HCT116 cells displayed attenuated vascular endothelial growth factor (VEGF) mRNA levels and hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) protein expression under hypoxic conditions. KRGE repressed Snail, Slug, and Twist mRNA expression and integrin ${\alpha}V{\beta}6$ protein levels. Furthermore, hypoxia-repressed E-cadherin was restored in KRGE-treated cells; KRGE blocked the invasion and migration of colon cancer cells by repressing $NF-{\kappa}B$ and ERK1/2 pathways in hypoxia. Conclusions: KRGE inhibits hypoxia-induced EMT by repressing $NF-{\kappa}B$ and ERK1/2 pathways in colon cancer cells.

• 한국식품위생안전성학회지
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• 제34권3호
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• pp.303-308
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• 2019

L-carnitine은 라이신과 메티오닌으로 생합성되며 골격근과 심근을 포함한 다양한 동물조직에서 발견된다. L-carnitine이 포함된 식품으로는 양고기, 소고기, 돼지고기 등이 있고 근육발달에 도움을 주며 뼈를 강화하거나 대사작용을 도와주는 기능을 하여 영양 보조제로 많이 섭취하는 것으로 알려져 있다. 최근 L-carnitine은 제 2형 당뇨병, 골다공증, 대사성 신경증후군 등의 다양한 질병의 약물로도 연구 되고 있으며 암에서는 치료 보조제로 개발되어있다. 하지만 대장암에서의 L-carnitine에 대한 효과 및 기전에 대해서는 명확하지 않고 연구된 바가 없기 때문에 본 연구에서 저자들은 L-carnitine의 효능을 인간대장암세포주 HCT116에서 규명하고자 하였다. L-carnitine은 세포 내 활성산소종 (ROS)를 높은 수준으로 증가시켜 세포 증식을 억제하였다. 또한, 세포 증식과 죽음에 관련한 단백질 ERK1/2와 p38을 유의적으로 활성화 시킨다는 것을 입증하였다. 이때, ERK1/2 억제제(PD98059)를 처치하여 ERK1/2의 활성화가 활성산소종 발생 및 세포사멸에 중요하다는 것을 밝혔다. 따라서, 본 연구 결과는 L-carnitine이 대장암세포주의 증식을 억제 할 수 있고 이는 대장암의 치료에 있어 잠재적인 치료 물질이 될 수 있음을 시사하며 이 과정에 관여하는 신호전달기전을 조사하여 항암의 치료기전에서 활성산소종이나 ERK1/2, p38 단백질의 활성화의 중요성을 제시하였다.

• Journal of Ginseng Research
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• 제41권2호
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• pp.227-231
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• 2017

Background: Ginsenosides are active components of Panax ginseng that exert various health benefits including kidney protection effect. The medicinal activity of ginsenosides can be enhanced by modulating their stereospecificity by heat processing. Ginsenosides Rk2 and Rh3 represent positional isomers of the double bond at C-20(21) or C-20(22). Methods: The present study investigated the kidney-protective effects of ginsenosides Rk2 and Rh3 against cisplatin, a platinum based anticancer drug, induced apoptotic damage in renal proximal LLC-PK1 cells. Results: As a result, ginsenoside Rh3 shows a stronger protective effect than that shown by Rk2. Cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), p38, and cleaved caspase-3 decreased after cotreatment with ginsenoside Rh3. The increase in the percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment also significantly reduced after cotreatment with ginsenoside Rh3. Conclusion: These results demonstrate that inhibition of the JNK and ERK mitogen-activated protein kinase signaling cascade plays a critical role in mediating the renoprotective effect of ginsenoside Rh3.

• 농업생명과학연구
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• 제50권2호
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• pp.139-150
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• 2016

말뼈추출물은 다양한 골질환의 예방과 치료에 탁월한 효능이 있다고 이전에 보고되었다. 하지만 말뼈추출물의 다른 약리학적 효능에 대해서는 아직 자세히 밝혀지지 않고있다. 본 연구에서는 말뼈추출물이 중요한 항산화 인자인 hemeoxygenase-1(HO-1)의 발현을 상승시킬 수 있는지, 만약 발현이 증가한다면 HO-1의 상향 조절이 대식세포에서 항염증 효과를 매개할 수 있는지에 관하여 조사하였다. 이를 위해서 nitric oxide(NO) 농도측정, 세포 생존능 측정, DPPH 라디칼 소거능 검사를 시행하였다. 또한 염증성 사이토카인 유전자 발현과 단백질 발현을 측정하기 위해 real time PCR과 Western blotting을 시행하였다. 말뼈추출물은 lipopolysaccharide(LPS, 0.1㎍/ml)로 자극한 대식세포주인 RAW264.7 세포에서 어떠한 세포독성 없이 NO의 생성을 유의성 있게 억제하였으며 inducible nitric oxide(iNOS)와 cyclooxygenase 2(COX-2)의 발현을 억제하였다. 뿐만 아니라 말뼈 추출물은 염증성 사이토카인인 tumor necrosis factor(TNF)-α와 interleukin(IL)-1β의 발현을 억제하였으며 ERK, JNK 및 p-38 MAPK의 단백질 인산화를 억제하였다. 그리고 말뼈추출물은 HO-1과 NF-E2-related factor-2(Nrf-2) 의 발현을 증가시켰고 이것은 말뼈추출물이 가지고 있는 항 염증효과를 매개할 수 있는 것으로 보인다. 즉, 말뼈추출물이 HO-1의 발현을 상향 조절한 반면 ERK1/2의 신호전달 경로에 손상을 주는 것으로 확인되었으며 이러한 말뼈추출물의 효과가 최종적으로 세포손상과 세포의 과산화 자극으로부터 세포를 보호 할 수 있는 것으로 사료된다.