Daucosterol linolenate from Sweet Potato Suppresses MCF7-Xenograft-Tumor Growth through Regulating PI3K/AKT Pathway

Planta Medica ◽  
2020 ◽  
Vol 86 (11) ◽  
pp. 767-775
Author(s):  
Bing Han ◽  
Lingmin Jiang ◽  
Pu Jiang ◽  
Deqi Zhou ◽  
Xiaoxin Jia ◽  
...  

AbstractSweet potato is a functional food with potential antitumor properties, but the bioactive constituents and biological mechanisms remain unclear. In this study, we investigated the antitumor effect of daucosterol linolenate extracted from sweet potato and its potential mechanism. An MTT assay indicated that DLA inhibited the proliferation of breast cancer MCF-7 cells but had only weak effects on the proliferation of MDA-MB-231, 4T1, and MCF-10A cells. Flow cytometry analysis revealed that daucosterol linolenate induced apoptosis of MCF-7 cells. Experiments with MCF-7 xenograft in nude mice further confirmed that DLA inhibited tumor growth dose-dependently. After DLA treatment, the expressions of B-cell lymphoma 2 and vascular endothelial growth factor were decreased and that of cleaved caspase 3 was increased as compared to the TC group. DLA also down-regulated the expression of phosphoinositide 3-kinase/protein kinase B and repressed insulin-induced phosphoinositide 3-kinase/protein kinase B activation. Our findings suggest that DLA suppresses breast tumor growth through inactivating the phosphoinositide 3-kinase/protein kinase B pathway.

2020 ◽  
Vol 19 (3) ◽  
pp. 317-325
Author(s):  
Chao Geng ◽  
Shaowu Ou

We have investigated the effectiveness of higenamine in the treatment of malignant glioma, and explored its possible mechanism in C6 glioma cells. The efficacy of higenamine on viability of cells, apoptosis, cell cycle arrest, DNA fragmentation, and biochemical markers was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, enzyme-linked immunosorbent assay, and Western blotting. The biochemical markers investigated included the effect of higenamine on the expression of phosphoinositide-3-kinase/protein kinase B, B-cell lymphoma 2, BCL2- associated X protein, cysteine-aspartic proteases-3 and -9 proteins. The translocation of nuclear factor-kappa B from the nucleus was also analyzed. Results revealed that higenamine induced cytotoxic and antiproliferative effects on the C6 glioma cells. Higenamine led to cell arrest at G2/M phase of cell cycle and lowered cell count at S-phase. The maximum extent of DNA fragmentation was observed after 72 h exposure of higenamine. Nuclear translocation of nuclear factorkappa B was attenuated after higenamine treatment in the C6 glioma cells. The results also revealed that higenamine significantly modulated the phosphoinositide-3-kinase/protein kinase B signaling cascade. Also, higenamine elevated the cysteine-aspartic proteases-3 and -9 and BCL2-associated X protein, and downregulated B-cell lymphoma 2 expression in the C6 glioma cells. Overall, the investigation suggests higenamine modulation of phosphoinositide-3-kinase/protein kinase B signaling pathway, nuclear factor-kappa B nuclear translocation, and caspase cascade in the C6 glioma cells.


2012 ◽  
Vol 12 (1) ◽  
pp. 1305-1313 ◽  
Author(s):  
DAN QU ◽  
XIAO-MAN XU ◽  
MENG ZHANG ◽  
TING-SHU JIANG ◽  
YI ZHANG ◽  
...  

2020 ◽  
Vol 19 (2) ◽  
pp. 206-210
Author(s):  
Feng Chen ◽  
Bei Zhang

Lupeol exhibits multiple pharmacological activities including, anticancerous, anti-inflammatory, and antioxidant. The aim of this study was to explore the anticancerous activity of lupeol on ovarian cancer cells and examine its mechanism of action. To this end, increasing concentrations of lupeol on cell viability, cell cycle, and apoptosis in Caov-3 cells were evaluated. Lupeol inhibited cell viability, induced G1 phase arrest in cell cycle, increased cell apoptosis, and inhibited the ratio of phospho-Akt/protein kinase B and phospho-mammalian target of rapamycin/mammalian target of rapamycin. In conclusion, these data suggest that lupeol may play a therapeutic role in ovarian cancer.


2005 ◽  
Vol 94 (5) ◽  
pp. 1277-1287 ◽  
Author(s):  
Maria Isabel Cerezo-Guisado ◽  
Luis Jesus Garcia-Marin ◽  
Maria Jesus Lorenzo ◽  
Maria Julia Bragado

1999 ◽  
Vol 19 (7) ◽  
pp. 5061-5072 ◽  
Author(s):  
Mirjana Andjelković ◽  
Sauveur-Michel Maira ◽  
Peter Cron ◽  
Peter J. Parker ◽  
Brian A. Hemmings

ABSTRACT Protein kinase B (PKB or Akt), a downstream effector of phosphoinositide 3-kinase (PI 3-kinase), has been implicated in insulin signaling and cell survival. PKB is regulated by phosphorylation on Thr308 by 3-phosphoinositide-dependent protein kinase 1 (PDK1) and on Ser473 by an unidentified kinase. We have used chimeric molecules of PKB to define different steps in the activation mechanism. A chimera which allows inducible membrane translocation by lipid second messengers that activate in vivo protein kinase C and not PKB was created. Following membrane attachment, the PKB fusion protein was rapidly activated and phosphorylated at the two key regulatory sites, Ser473 and Thr308, in the absence of further cell stimulation. This finding indicated that both PDK1 and the Ser473 kinase may be localized at the membrane of unstimulated cells, which was confirmed for PDK1 by immunofluorescence studies. Significantly, PI 3-kinase inhibitors prevent the phosphorylation of both regulatory sites of the membrane-targeted PKB chimera. Furthermore, we show that PKB activated at the membrane was rapidly dephosphorylated following inhibition of PI 3-kinase, with Ser473 being a better substrate for protein phosphatase. Overall, the results demonstrate that PKB is stringently regulated by signaling pathways that control both phosphorylation/activation and dephosphorylation/inactivation of this pivotal protein kinase.


2010 ◽  
Vol 104 (7) ◽  
pp. 957-964 ◽  
Author(s):  
Jong-Eun Kim ◽  
Joe Eun Son ◽  
Sung Keun Jung ◽  
Nam Joo Kang ◽  
Chang Yong Lee ◽  
...  

Cocoa polyphenols have antioxidant and anti-inflammatory effects. TNF-α is a pro-inflammatory cytokine that has a vital role in the pathogenesis of inflammatory diseases such as cancer and psoriasis. Vascular endothelial growth factor (VEGF) expression is associated with tumorigenesis, CVD, rheumatoid arthritis and psoriasis. We tested whether cocoa polyphenol extract (CPE) inhibited TNF-α-induced VEGF expression in promotion-sensitive JB6 mouse epidermal cells. CPE significantly inhibited TNF-α-induced up-regulation of VEGF via reducing TNF-α-induced activation of the nuclear transcription factors activator protein-1 (AP-1) and NF-κB, which are key regulators of VEGF expression. CPE also inhibited TNF-α-induced phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase. CPE blocked activation of their downstream kinases, p70 kDa ribosomal protein S6 kinase and p90 kDa ribosomal protein S6 kinase. CPE suppressed phosphoinositide 3-kinase (PI3K) activity via binding PI3K directly. CPE did not affect TNF-α-induced phosphorylation of mitogen-activated protein kinase kinase-1 (MEK1) but suppressed TNF-α-induced MEK1 activity. Collectively, these results indicate that CPE reduced TNF-α-induced up-regulation of VEGF by directly inhibiting PI3K and MEK1 activities, which may contribute to its chemopreventive potential.


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