• 제목/요약/키워드: autophagy

검색결과 472건 처리시간 0.032초

에스트로겐 수용체 양성 MCF-7 유방암 세포주에 대한 costunolide의 항암효과 (Anti-cancer Effects of Costunolide in Estrogen Receptor Positive MCF-7 Breast Cancer Cells)

  • 김운지;최윤경;우상미;박남규;정혜인;김용국;신용철;고성규
    • 동의생리병리학회지
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    • 제27권3호
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    • pp.306-312
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    • 2013
  • Costunolide ($C_{15}H_{20}O_2$) is a sesquiterpene lactone that was isolated from many herbal medicines and it has diverse effects (anti-viral, anti-fungal, and anti-inflammatory) according to previous reports. However, the anti-cancer effects of Costunolide and its mechanism of actions are not well known in estrogen receptor positive breast cancer. In this study, we observed that costunolide suppresses cell growth in estrogen receptor positive MCF-7 breast cancer cells as shown by MTT assay and soft agar colony formation assay. To examine the mechanism by which costunolide inhibits MCF-7 cell growth, we performed FACS analysis. We found that costunolide induced G2/M and S cell cycle arrest, and regulated cycle-related protein expression. In addition, costunolide inhibited ERK signaling pathway and induced autophagy. Therefore, costunolide might be a good and useful chemotherapy agent for estrogen receptor positive breast cancer patients.

Antitumor Activity of Chloroquine in Combination with Cisplatin in Human Gastric Cancer Xenografts

  • Zhang, Hui-Qing;Fang, Nian;Liu, Xiao-Mei;Xiong, Shu-Ping;Liao, Yu-Qian;Jin, Wen-Jian;Song, Rong-Feng;Wan, Yi-Ye
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권9호
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    • pp.3907-3912
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    • 2015
  • Purpose: To investigate the antitumor activity and mechanism of chloroquine (CQ) in combination with cisplatin (DDP) in nude mice xenografted with gastric cancer SGC7901 cells. Materials and Methods: 35 cases of gastric cancer patients with malignant ascites were enrolled and intraperitoneal cisplatin injection was performed. Ascites were collected before and 5 days after perfusion for assessment of autophagy levels in cancer cells. In addition, 24 tumor-bearing mice were randomly divided into control, DDP, CQ and CQ + DDP groups. Results: In 54.3% (19/35) of patients the treatment was therapeutically effective (OR), 5 days after peritoneal chemotherapy, 13 patients had the decreased ascites Beclin-1 mRNA levels. In 16 patients who had NR, only 2 cases had decreased Beclin-1 (P=0.001). Compared with the control group, the xenograft growth in nude mice in the DDP group was low, and the inhibition rate was 47.6%. In combination with chloroquine, the inhibition rate increased to 84.7% (P<0.01). The LC3-II/I ratio, and Beclin1 and MDR1/P-gp expression were decreased, while caspase 3 protein levels increased (P<0.05). Conclusions: Antitumor ability of cisplatin was associated with autophagy activity and chloroquine can enhance chemosensitivity to cisplatin in gastric cancer xenografts nude mice.

Anti-tumor Efficacy of a Hepatocellular Carcinoma Vaccine Based on Dendritic Cells Combined with Tumor-derived Autophagosomes in Murine Models

  • Su, Shu;Zhou, Hao;Xue, Meng;Liu, Jing-Yu;Ding, Lei;Cao, Meng;Zhou, Zhen-Xian;Hu, Hong-Min;Wang, Li-Xin
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권5호
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    • pp.3109-3116
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    • 2013
  • The majority of hepatocellular carcinoma (HCC) patients have a poor prognosis with current therapies, and new approaches are urgently needed. We have developed a novel therapeutic cancer vaccine platform based on tumor cell derived autophagosomes (DRibbles) for cancer immunotherapy. We here evaluated the effectiveness of DRibbles-pulsed dendritic cell (DC) immunization to induce anti-tumor immunity in BALB/c mouse HCC and humanized HCC mouse models generated by transplantation of human HCC cells (HepG2) into BALB/c-nu mice. DRibbles were enriched from H22 or BNL cells, BALB/c-derived HCC cell lines, by inducing autophagy and blocking protein degradation. DRibbles-pulsed DC immunization induced a specific T cell response against HCC and resulted in significant inhibition of tumor growth compared to mice treated with DCs alone. Antitumor efficacy of the DCs-DRibbles vaccine was also demonstrated in a humanized HCC mouse model. The results indicated that HCC/DRibbles-pulsed DCs immunotherapy might be useful for suppressing the growth of residual tumors after primary therapy of human HCC.

Inhibition of mTOR signaling pathway by aqueous extract of Siberian ginseng

  • Byun, Boo Hyeong;Cho, Tae Hwan;Park, Kyeong Mee
    • 대한한의학회지
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    • 제38권2호
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    • pp.7-14
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    • 2017
  • Objectives: This study evaluated the effect of aqueous extract from roots of Siberian ginseng on mTORC1 pathway. Methods: mTORC1 activity was measured by the phosphorylation status of p70 S6 kinase (S6K) in HeLa cells as well as the brain, liver and muscle tissues in diabetic db/db mice. Autophagy induction after the treatment of Siberian ginseng extract was evaluated by monitoring the conversion of cytoplasmic LC3I into lipidated LC3II in cultured human HeLa GFP-LC3 cells. Cell cycle analysis was performed in HeLa cells treated with Siberian ginseng using flow cytometry. Results: Among >2,800 plant products used for oriental medicine, Siberian ginseng was found to inhibit mTORC1 to phosphorylate S6 kinsase (S6K) in HeLa cells as well as the brain, liver and muscle tissues in diabetic db/db mice. Siberian ginseng-mediated mTORC1 activity was reversible unlike the prolonged suppression of mTORC1 by rapamycin when HeLa cells were grown in fresh media after the removal of the inhibitors. Siberian ginseng extract at concentrations to inhibit mTORC1 was not overly cytotoxic in cultured HeLa cells whereas rapamycin was obviously cytotoxic. The conversion of cytoplasmic LCI into lipidated LCII was increased by fivefold in HeLa GFP-LC3 cells treated with Siberian ginseng extract. Progression of cell cycle was attenuated at G2/M phase by the treatment of Siberian ginseng extract. Conclusions: These results suggest that the aqueous extract of Siberian ginseng possibly plays a good therapeutic role in various diseases involving mTORC1 signaling.

Adenovirus vector-mediated FAM176A overexpression induces cell death in human H1299 non-small cell lung cancer cells

  • Xie, Hong;Hu, Jia;Pan, Huan;Lou, Yaxin;Lv, Ping;Chen, Yingyu
    • BMB Reports
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    • 제47권2호
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    • pp.104-109
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    • 2014
  • FAM176A (family with sequence similarity 176 member A) is a novel molecule related to programmed cell death. A decreased expression of FAM176A has been found in several types of human tumors in including lung cancers. In the present study, we investigated the biological activities of FAM176A on the human non-small cell lung cancer cell line H1299 cells. We constructed a recombinant adenovirus 5-FAM176A vector (Ad5-FAM176A) and evaluated the expression and anti-tumor activities in vitro. Cell viability analysis revealed that the adenovirus-mediated increase of FAM176A inhibited the growth of the tumor cells in a dose- and time-dependent manner. This inhibitory effect was mediated by both autophagy and apoptosis that involved caspase activation. In addition, cell cycle analysis suggested that Ad5-FAM176A could induce cell cycle arrest at the G2/M phase, all of which suggested that adenovirus-mediated FAM176A gene transfer might present a new therapeutic approach for lung cancer treatment.

Suppression of Autophagy and Activation of Glycogen Synthase Kinase 3beta Facilitate the Aggregate Formation of Tau

  • Kim, Song-In;Lee, Won-Ki;Kang, Sang-Soo;Lee, Sue-Young;Jeong, Myeong-Ja;Lee, Hee-Jae;Kim, Sung-Soo;Johnson, Gall V.W.;Chun, Wan-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • 제15권2호
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    • pp.107-114
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    • 2011
  • Neurofibrillary tangle (NFT) is a characteristic hallmark of Alzheimer's disease. GSK3β has been reported to play a major role in the NFT formation of tau. Dysfunction of autophagy might facilitate the aggregate formation of tau. The present study examined the role of GSK3${\beta}$-mediated phosphorylation of tau species on their autophagic degradation. We transfected wild type tau (T4), caspase-3-cleaved tau at Asp421 (T4C3), or pseudophosphorylated tau at Ser396/Ser404 (T4-2EC) in the presence of active or enzyme-inactive GSK3${\beta}$. Trehalose and 3-methyladenine (3-MA) were used to enhance or inhibit autophagic activity, respectively. All tau species showed increased accumulation with 3-MA treatment whereas reduced with trehalose, indicating that tau undergoes autophagic degradation. However, T4C3 and T4-2EC showed abundant formation of oligomers than T4. Active GSK3${\beta}$ in the presence of 3-MA resulted in significantly increased formation of insoluble tau aggregates. These results indicate that GSK3${\beta}$-mediated phosphorylation and compromised autophagic activity significantly contribute to tau aggregation.

Induction of Cell Death by Betulinic Acid through Induction of Apoptosis and Inhibition of Autophagic Flux in Microglia BV-2 Cells

  • Seo, Jeongbin;Jung, Juneyoung;Jang, Dae Sik;Kim, Joungmok;Kim, Jeong Hee
    • Biomolecules & Therapeutics
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    • 제25권6호
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    • pp.618-624
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    • 2017
  • Betulinic acid (BA), a natural pentacyclic triterpene found in many medicinal plants is known to have various biological activity including tumor suppression and anti-inflammatory effects. In this study, the cell-death induction effect of BA was investigated in BV-2 microglia cells. BA was cytotoxic to BV-2 cells with $IC_{50}$ of approximately $2.0{\mu}M$. Treatment of BA resulted in a dose-dependent chromosomal DNA degradation, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that BA-treated BV-2 cells showed hypodiploid DNA content. BA treatment triggered apoptosis by decreasing Bcl-2 levels, activation of capase-3 protease and cleavage of PARP. In addition, BA treatment induced the accumulation of p62 and the increase in conversion of LC3-I to LC3-II, which are important autophagic flux monitoring markers. The increase in LC3-II indicates that BA treatment induced autophagosome formation, however, accumulation of p62 represents that the downstream autophagy pathway is blocked. It is demonstrated that BA induced cell death of BV-2 cells by inducing apoptosis and inhibiting autophagic flux. These data may provide important new information towards understanding the mechanisms by which BA induce cell death in microglia BV-2 cells.

Increase in apoptotic effect of Panax ginseng by microwave processing in human prostate cancer cells: in vitro and in vivo studies

  • Park, Jun Yeon;Choi, Pilju;Kim, Ho-kyong;Kang, Ki Sung;Ham, Jungyeob
    • Journal of Ginseng Research
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    • 제40권1호
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    • pp.62-67
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    • 2016
  • Background: Ginseng, which is widely used in functional foods and as an herbal medicine, has been reported to reduce the proliferation of prostate cancer cells by mechanisms that are not yet fully understood. Methods: This study was designed to investigate the changes in ginsenoside content in ginseng after treatment with a microwave-irradiation thermal process and to verify the anticancer effects of the extracts. To confirm the anticancer effect of microwave-irradiated processed ginseng (MG), it was tested in three human prostate cancer cell lines (DU145, LNCaP, and PC-3 cells). Involvements of apoptosis and autophagy were assessed using Western blotting. Results: After microwave treatment, the content of ginsenosides Rg1, Re, Rb1, Rc, Rb2, and Rd in the extracts decreased, whereas the content of ginsenosides 20(S)-Rg3, 20(R)-Rg3, Rk1, and Rg5 increased. Antiproliferation results for the human cancer cell lines treated with ginseng extracts indicate that PC-3 cells treated with MG showed the highest activity with an half maximal inhibitory concentration of $48{\mu}g/mL$. We also showed that MG suppresses the growth of human prostate cancer cell xenografts in athymic nude mice as an in vivo model. This growth suppression by MG is associated with the inductions of cell death and autophagy. Conclusion: Therefore, heat processing by microwave irradiation is a useful method to enhance the anticancer effect of ginseng by increasing the content of ginsenosides Rg3, Rg5, and Rk1.

Modulation of Mitochondrial Membrane Potential and ROS Generation by Nicotinamide in a Manner Independent of SIRT1 and Mitophagy

  • Song, Seon Beom;Jang, So-Young;Kang, Hyun Tae;Wei, Bie;Jeoun, Un-woo;Yoon, Gye Soon;Hwang, Eun Seong
    • Molecules and Cells
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    • 제40권7호
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    • pp.503-514
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    • 2017
  • Nicotinamide (NAM) plays essential roles in physiology through facilitating $NAD^+$ redox homeostasis. Importantly, at high doses, it protects cells under oxidative stresses, and has shown therapeutic effectiveness in a variety of disease conditions. In our previous studies, NAM lowered reactive oxygen species (ROS) levels and extended cellular life span in primary human cells. In the treated cells, levels of $NAD^+/NADH$ and SIRT1 activity increased, while mitochondrial content decreased through autophagy activation. The remaining mitochondria were marked with low superoxide levels and high membrane potentials (${\Delta}_{{\Psi}m}$); we posited that the treatment of NAM induced an activation of mitophagy that is selective for depolarized mitochondria, which produce high levels of ROS. However, evidence for the selective mitophagy that is mediated by SIRT1 has never been provided. This study sought to explain the mechanisms by which NAM lowers ROS levels and increases ${\Delta}_{{\Psi}m}$. Our results showed that NAM and SIRT1 activation exert quite different effects on mitochondrial physiology. Furthermore, the changes in ROS and ${\Delta}_{{\Psi}m}$ were not found to be mediated through autophagy or SIRT activation. Rather, NAM suppressed superoxide generation via a direct reduction of electron transport, and increased ${\Delta}_{{\Psi}m}$ via suppression of mitochondrial permeability transition pore formation. Our results dissected the effects of cellular $NAD^+$ redox modulation, and emphasized the importance of the $NAD^+/NADH$ ratio in the mitochondria as well as the cytosol in maintaining mitochondrial quality.

Significance of Vesicle-Associated Membrane Protein 8 Expression in Predicting Survival in Breast Cancer

  • Yuan, Mengci;Liao, Jianhua;Luo, Ji;Cui, Mengyao;Jin, Feng
    • Journal of Breast Cancer
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    • 제21권4호
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    • pp.399-405
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    • 2018
  • Purpose: Vesicle-associated membrane protein 8 (VAMP8) is a soluble N-ethylmaleimide-sensitive factor receptor protein that participates in autophagy by directly regulating autophagosome membrane fusion and has been reported to be involved in tumor progression. Nevertheless, the expression and prognostic value of VAMP8 in breast cancer (BC) remain unknown. This study aimed to evaluate the clinical significance and biological function of VAMP8 in BC. Methods: A total of 112 BC samples and 30 normal mammary gland samples were collected. The expression of VAMP8 was assessed in both BC tissues and normal mammary gland tissues via a two-step immunohistochemical detection method. Results: The expression of VAMP8 in BC tissues was significantly higher than that in normal breast tissues. Furthermore, increased VAMP8 expression was significantly correlated with tumor size (p=0.007), lymph node metastasis (p=0.024) and recurrence (p=0.001). Patients with high VAMP8 expression had significantly lower cumulative recurrence-free survival and overall survival (p<0.001 for both) than patients with low VAMP8 expression. In multivariate logistic regression and Cox regression analyses, lymph node metastasis and VAMP8 expression were independent prognostic factors for BC. Conclusion: VAMP8 is significantly upregulated in human BC tissues and can thus be a practical and potentially effective surrogate marker for survival in BC patients.