• 제목/요약/키워드: p-Akt

검색결과 440건 처리시간 0.036초

Bee venom의 세포자멸사를 통한 전립선 암세포의 성장 및 LNCaP의 이종이식에 미치는 영향 (Bee Venom Inhibits Prostate Cancer Growth in LNCaP Xenografts via Apoptosis)

  • 양창열;송호섭
    • 대한약침학회지
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    • 제13권1호
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    • pp.15-35
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    • 2010
  • 연구목적 : 이 연구는 봉약침의 봉독이 NF-${\kappa}B$ 활성억제와 안드로겐 수용체 조절 단백질 및 세포자멸사 조절 단백질의 발현을 통하여 세포자멸사를 유도하고, 전립선 암세포를 이식한 쥐에서의 세포자멸사 유도 효과를 확인함으로써, 봉약침의 봉독이 생체 내에서도 세포자멸사를 유도하여 전립선암에 효과를 나타냄을 확인하고자 하였다. 실험방법 : 세포자멸사의 관찰에는 DAPI, TUNEL staining assay를 시행하였으며, 세포자멸사 조절 단백질의 변동 관찰에는 western blot analysis를 시행하였고, 세포자멸사와 연관된 NF-${\kappa}B$의 활성 변화를 관찰하기 위해 EMSA를 시행하였다. 결과 : 1. DAPI, TUNEL staining assay 결과 봉독 및 melittin을 처리한 LNCaP 세포 모두에서 세포자멸사 유도율이 유의한 증가를 나타내었다. 2. LNCaP 세포에 봉독이나 melittin을 처리한 결과, 안드로겐 수용체 조절 단백질 중 p-Akt, COX-2, calpain은 봉독과 melittin 모두에서 유의한 감소를 나타내었고, Akt는 melittin에서 유의한 감소를 나타냈으며, 봉독에서 증가하는 경향을 보였고, MMP-9은 증가하였다. 3. 생체 내에서의 봉독의 항암효과를 확인하기 위해 전립선암세포가 이식된 쥐에 봉독을 처리한 후 암세포의 부피와 무게, 쥐의 체중을 측정한 결과, 봉독을 처리한 군에서 암 세포 부피비율 및 무게는 감소하였고, 쥐의 체중은 증가하였다. 4. 전립선암세포가 이식된 쥐에 봉독을 처리한 결과, NF-${\kappa}B$ 활성에서 유의한 감소를 나타내었다. 5. 전립선암세포가 이식된 쥐에 봉독을 처리한 결과, 세포자멸사 조절 단백질 중 Bax/Bcl-2, p53, caspase-3, caspase-9, calpain은 유의한 증가를, COX-2는 유의한 감소를 나타냈으며, MMP-9는 증가를 나타내었다. 결론 : 이상의 결과는 봉독이 시험관 내에서 뿐만 아니라 생체 내에서도 NF-${\kappa}B$의 활성을 억제하고 안드로겐 수용체 조절 단백질 및 세포자멸사 조절 단백질의 조절을 통하여 인간 전립선암 세포주인 LNCaP의 세포자멸사를 유도함으로써 전립선암 세포 증식억제 효과 및 호르몬 비의존적인 전립선암으로의 전이를 지연시키는 경향이 있을 것으로 사료되고, 봉독이 전립선암의 예방과 치료에 효과적으로 활용될 수 있을 것으로 기대된다.

Sphingosine-1-phosphate Inhibits Human Keratinocyte Proliferation via Akt/PKB Inactivation

  • Kim, Dong-Seok;Kim, Sook-Young;Kim, Kyu-Han;Park, Kyoung-Chan
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.76.2-76.2
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    • 2003
  • Although sphingosine-1-phosphate (S1P) is a well-known mitogen, our results show that S1P potently inhibits keratinocyte proliferation, and that this leads the inhibition of DNA synthesis. Interestingly, the prolonged activation of extracellular signal-regulated protein kinase (ERK) and the transient inactivation of Akt/protein kinase B (PKB) were also oberved in concert with the inhibition of keratinocyte proliferation by S1P. To further verify the anti-proliferative action of S1P, we examined changes in cell cycle related proteins. (omitted)

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Radish (Raphanus sativus L. leaf) ethanol extract inhibits protein and mRNA expression of $ErbB_2$ and $ErbB_3$ in MDA-MB-231 human breast cancer cells

  • Kim, Woo-Kyoung;Kim, Ji-Hae;Jeong, Da-Hee;Chun, Young-Hee;Kim, Sun-Hee;Cho, Kang-Jin;Chang, Moon-Jeong
    • Nutrition Research and Practice
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    • 제5권4호
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    • pp.288-293
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    • 2011
  • In this study, we investigated the effects of the ethanol extract of aerial parts of Raphanus sativus L. (ERL) on breast cancer cell proliferation and gene expression associated with cell proliferation and apoptosis in MDA-MB-231 human breast cancer cells. The MDA-MB-231 cells were cultured in the presence or absence of various concentrations (100, 200, or 300 ${\mu}g$/mL) of ERL. ERL significantly decreased cell proliferation after 48 h of incubation (P < 0.05). The protein and mRNA expression of $ErbB_2$ were decreased significantly in a dose-dependent manner (P < 0.05). The protein expression of $ErbB_3$ was decreased significantly at an ERL concentration of 300 ${\mu}g$/mL (P < 0.05), and mRNA expression of $ErbB_3$ was decreased significantly in a dose-dependent manner (P < 0.05). The protein expression of Akt was decreased significantly at the ERL concentration of 200 ${\mu}g$/mL (P < 0.05), and the protein expression of pAkt was decreased significantly in a dose-dependent manner (P < 0.05). The mRNA expression of Akt was decreased significantly at the ERL concentration of 200 ${\mu}g$/mL ERL (P < 0.05). The protein and mRNA expression of Bax were increased significantly at ERL concentrations of 200 ${\mu}g$/mL or higher (P < 0.05). The protein expression of $Bcl_2$ was increased significantly at ERL concentrations of 100 ${\mu}g$/mL or higher (P < 0.05), and mRNA expression of $Bcl_2$ was increased significantly at an ERL concentration of 300 ${\mu}g$/mL (P < 0.05). In conclusion, we suggest that Raphanus sativus, L. inhibits cell proliferation via the ErbB-Akt pathway in MDA-MB-231 cells.

17-DMAG이 마우스 골격근에서 autophagy flux에 미치는 영향 (Effects of 17-DMAG Administration on Autophagy Flux in Mouse Skeletal Muscle)

  • 주정선;이유현
    • 생명과학회지
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    • 제26권4호
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    • pp.387-397
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    • 2016
  • 본 연구는 17-DMAG이 골격근에서 autophagy에 관여하는 가를 조사하기 위해, C2C12세포와 마우스 골격근에서 17-DMAG (Hsp90 억제제/Hsp72 활성제)을 처치하는 그룹과 autophagy 억제제(Bafilomycin 또는 colchicine)를 처치하는 그룹과 처치하지 않는 그룹을 동시에 두고 autophagy flux를 측정하였다. C2C12 배양세포에서 17-DMAG이 Hsp90 억제/hsp72 활성화시켰으며 Akt-mTOR 신호체계를 유의하게 감소시켰지만(p<0.05) autophagy marker 단백질인 LC3 II와 p62를 증가시키지 않았다. in vivo 모델의 경우 17-DMAG 처치가 배양세포에서 발견된 것처럼 Hsp90억제/hsp72를 활성화시켰고 Akt-mTOR 신호체계를 유의하게 감소시켰다(p<0.05). 반면 LC3 II와 p62 단백질 수준은 autophagy 억제제(colchicine) 처치 수준보다 더 높게 증가되었다. 이는 17-DMAG이 골격근에서 autophagy를 증가시키지만 C2C12 배양세포에서는 autophagy의 활성화가 제한적임을 암시한다. 현재 이러한 in vitro와 in vivo 모델에서의 차이는 불분명하다.

HepG2 인체 간암세포의 ROS 생성 및 ERK/Akt 신호전달 경로 조절을 통한 sanguinarine의 apoptosis 유도 (Sanguinarine Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells through the Generation of ROS and Modulation of Akt/ERK Signaling Pathways)

  • 황주영;최영현
    • 생명과학회지
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    • 제25권9호
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    • pp.984-992
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    • 2015
  • 혈근초(Sanguinaria canadensis)에서 처음 분리된 sanguinarine은 항산화, 항암 및 면역 증강 등의 효능이 있는 것으로 알려진 alkaloid 계열 물질 중의 하나이다. 본 연구에서는 인체간암 HepG2 세포를 대상으로 sanguinarine의 apoptosis 유도 효능 및 관련 기전 해석을 시도하였다. 본 연구의 결과에 의하면 sanguinarine은 HepG2 간암세포의 증식을 처리 농도 의존적으로 억제하였으며, 이는 apoptosis 유도와 연관성이 있었다. Sanguinarine에 의한 apoptosis 유도에는 Fas 및 Bax의 발현 증가, 미토콘드리아에서 세포질로의 cytochrome c 유리 및 MMPl (Δψm)의 소실을 동반하였다. Sanguinarine은 intrinsic 및 extrinsic apoptosis pathway의 활성에 관여하는 initiator caspase인 caspase-9와 -8의 활성과 effector caspase인 caspase-3의 활성 및 PARP 단백질의 단편화를 유발하였다. Sanguinarine은 또한 ROS의 생성을 촉진시켰으며, N-acetylcysteine 처리에 의한 ROS의 생성을 차단하였을 경우, sanguinarine에 의한 apoptosis 효능이 완벽하게 차단되었다. 아울러 sanguinarine은 Akt의 인산화를 억제한 반면, MAPKs의 인산화를 촉진시켰으며, 특히 PI3K와 ERK의 선택적 억제제는 sanguinarine에 의한 HepG2 간암세포의 증식을 더욱 억제시켰다. 따라서 sanguinarine에 의한 HepG2 간암세포의 apoptosis 유발에는 ROS 생성 의존적인 intrinsic 및 extrinsic signaling pathway가 동시에 활성화되며, PI3K/Akt 및 ERK 신호계가 관여함을 알 수 있었다.

PKB phosphorylates p27, impairs its nuclear import and opposes p27-mediated G1 arrest

  • Lee, Jin-Hwa;Liang, Ji-Yong;Slingerland, Joyce M.
    • 한국생명과학회:학술대회논문집
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    • 한국생명과학회 2002년도 제37회 국제학술심포지움 및 추계학술대회
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    • pp.36-39
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    • 2002
  • PKB activation may contribute to resistance to antiproliferative signals and breast cancer progression in part by impairing nuclear import and action of p27. PKB transfection caused cytoplasmic p27 accumulation and cytokine resistance. The nuclear localization region of p27 contains a PKB/Akt consensus site at threonine 157 and p27 phosphorylation by PKB impaired its nuclear import in vitro. PKB/Akt phosphorylated wild type p27 but not p27T157A. PKB activation led to cytoplasmic mislocalization of p27WT but p27T157A remained nuclear. In PKB activated cells, p27WT failed to cause Gl arrest, while the antiproliferative effect of p27T157A was not impaired. Cytoplasmic p27 was seen in 41% (52/128) of primary human breast cancers in association with PKB activation. Thus, we show a novel mechanism whereby PKB impairs p27 function that is associated with an aggressive phenotype in human breast cancer.

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Critical role of protein L-isoaspartyl methyltransferase in basic fibroblast growth factor-mediated neuronal cell differentiation

  • Dung, To Thi Mai;Yi, Young-Su;Heo, Jieun;Yang, Woo Seok;Kim, Ji Hye;Kim, Han Gyung;Park, Jae Gwang;Yoo, Byong Chul;Cho, Jae Youl;Hong, Sungyoul
    • BMB Reports
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    • 제49권8호
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    • pp.437-442
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    • 2016
  • We aimed to study the role of protein L-isoaspartyl methyltransferase (PIMT) in neuronal differentiation using basic fibroblast growth factor (bFGF)-induced neuronal differentiation, characterized by cell-body shrinkage, long neurite outgrowth, and expression of neuronal differentiation markers light and medium neurofilaments (NF). The bFGF-mediated neuronal differentiation of PC12 cells was induced through activation of mitogen-activated protein kinase (MAPK) signaling molecules [MAPK kinase 1/2 (MEK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2), and p90RSK], and phosphatidylinositide 3-kinase (PI3K)/Akt signaling molecules PI3Kp110β, PI3Kp110γ, Akt, and mTOR. Inhibitors (adenosine dialdehyde and S-adenosylhomocysteine) of protein methylation suppressed bFGF-mediated neuronal differentiation of PC12 cells. PIMT-eficiency caused by PIMT-specific siRNA inhibited neuronal differentiation of PC12 cells by suppressing phosphorylation of MEK1/2 and ERK1/2 in the MAPK signaling pathway and Akt and mTOR in the PI3K/Akt signaling pathway. Therefore, these results suggested that PIMT was critical for bFGF-mediated neuronal differentiation of PC12 cells and regulated the MAPK and Akt signaling pathways.

Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis

  • Yang, Jung-Bo;Quan, Juan-Hua;Kim, Ye-Eun;Rhee, Yun-Ee;Kang, Byung-Hyun;Choi, In-Wook;Cha, Guang-Ho;Yuk, Jae-Min;Lee, Young-Ha
    • Parasites, Hosts and Diseases
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    • 제53권4호
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    • pp.371-377
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    • 2015
  • Trichomonas vaginalis induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in $TNF-{\alpha}$ production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased $TNF-{\alpha}$ production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, $TNF-{\alpha}$ production was significantly decreased compared to the control; however, $TNF-{\alpha}$ reduction patterns were different depending on the type of PI3K/MAPK inhibitors. $TNF-{\alpha}$ production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of $TNF-{\alpha}$ production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

Effect of Withaferin A on A549 Cellular Proliferation and Apoptosis in Non-small Cell Lung Cancer

  • Cai, Yong;Sheng, Zhao-Ying;Chen, Yun;Bai, Chong
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권4호
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    • pp.1711-1714
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    • 2014
  • Objective: To explore the effect of Withaferin A on A549 cellular proliferation and apoptosis in non-small cell lung cancer (NSCLC). Materials and Methods: NSCLC cell line A549 was selected to explore the effect of Withaferin A on A549 cellular proliferation, apoptosis and the PI3K/Akt signal pathway capable of regulating tumor biological behavior by assessment of cellular proliferation, cellular apoptotic rates and cellular cycling as well as by immuno-blotting. Results: Withaferin A could inhibit A549 cellular proliferation and the control rate was dosage-dependent (P<0.05), which also increased time-dependently with the same dosage of Withaferin A (P<0.05). The apoptotic indexes in A549 cells treated with 0, 2.5, 5.0, 10.0 and 20.0 ${\mu}mol{\cdot}L^{-1}$ Withaferin A for 48 h were significantly different (P<0.05). In addition, the apoptotic rates of each group in both early and advanced stages were higher than those in 0 ${\mu}mol{\cdot}L^{-1}$ (P<0.05), which were evidently higher after 48 h than those after 24 h (P<0.05). A549 cells treated by Withaferin A for 48 h were markedly lower in Bcl-2 level and obviously higher in Bax and cleaved caspase-3 levels than those treated by 0 ${\mu}mol{\cdot}L^{-1}$ Withaferin A (P<0.05), and there were significant differences among 5, 10 and 20 ${\mu}mol{\cdot}L^{-1}$ Withaferin A (P<0.05). The ratios of A549 cells treated by Withaferin A for 48 h in G0/G1 stage were higher than those in 0 ${\mu}mol{\cdot}L^{-1}$, while those in S and G2/M stages were obviously lower than those in G2/M stage, and there were significant differences in 5.0, 10.0 and 20.0 ${\mu}mol{\cdot}L^{-1}$ Withaferin A (P<0.05). Additionally, p-Akt/Akt values were in reverse association with dosage, and the differences were significant (P<0.05). Conclusion: Withaferin A can inhibit the proliferation and apoptosis of A549 cells by suppressing activation of the PI3K/Akt pathways.

MiR-21 Upregulation Induced by Promoter Zone Histone Acetylation is Associated with Chemoresistance to Gemcitabine and Enhanced Malignancy of Pancreatic Cancer Cells

  • Song, Wei-Feng;Wang, Lei;Huang, Wei-Yi;Cai, Xun;Cui, Jiu-Jie;Wang, Li-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7529-7536
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    • 2013
  • Background and Aims: MicroRNA-21 (miR-21) is reported to be overexpressed and to contribute to proliferation, apoptosis and gemcitabine resistance in pancreatic ductal adenocarcinomas (PDACs). The aims of this study were to explore regulation of miR-21 expression by epigenetic change and its impact on chemoresistance and malignant properties of of pancreatic cancer. Materials and methods: We retrospectively collected 41 cases of advanced pancreatic cancer patients who were sensitive or resistant to gemcitabine and assessed levels of serum circulating miR-21 for correlation with cytotoxic activity. Histone acetylation in the miR-21 promoter was also studied in gemcitabine-sensitive and gemcitabine-resistant PDAC cells. Gemcitabine-resistant HPAC and PANC-1 cells were transfected with pre-miR-21 precursors (pre-miR-21) and antisense oligonucleotides (anti-miR-21), and were treated with TSA. Finally, invasion and metastasis assays were performed and alteration in mir-21, PTEN, AKT and pAKT level was evaluated in these cells. Results: Serum miR-21 levels were increased in gemcitabine-resistant PDAC patients compared with gemcitabine-sensitive subjects. The miR-21 levels were increased in 6 PDAC cells treated with gemcitabine significantly, associated with 50% inhibitory concentrations ($IC_{50}s$). Histone acetylation levels at miR-21 promoter were increased in PDAC cells after treatment with gemcitabine. Enhanced invasion and metastasis, increased miR-21 expression, decreased PTEN, elevated pAKT level were demonstrated in gemcitabine-resistant HPAC and PANC-1 cells. Pre-miR-21 transfection or TSA treatment further increased invasion and metastasis ability, decreased PTEN, and elevated pAKT levels in these two lines. In contrast, anti-miR-21 transfection could reverse invasion and metastasis, and PTEN and pAKT expressions induced by gemcitabine. Conclusions: MiR-21 upregulation induced by histone acetylation in the promoter zone is associated with chemoresistance to gemcitabine and enhanced malignant potential in pancreatic cancer cells.