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Dihydroartemisinin induces endothelial cell anoikis through the activation of the JNK signaling pathway

View Article: PubMed Central - PubMed

ABSTRACT

Angiogenesis is required for the growth and metastasis of solid tumors. The anti-malarial agent dihydroartemisinin (DHA) demonstrates potent anti-angiogenic activity, but the underlying molecular mechanisms are not yet fully understood. During the process of angiogenesis, endothelial cells migrating from existing capillaries may undergo programmed cell death after detaching from the extracellular matrix, a process that is defined as anchorage-dependent apoptosis or anoikis. In the present study, DHA-induced cell death was compared in human umbilical vein endothelial cells (HUVECs) cultured in suspension and attached to culture plates. In suspended HUVECs, the cell viability was decreased and apoptosis was increased with the treatment of 50 µM DHA for 5 h, while the same treatment did not affect the attached HUVECs. In addition, 50 µM DHA increased the phosphorylation of c-Jun N-terminal kinase (JNK) in suspended HUVECs, but not in attached HUVECs, for up to 5 h of treatment. The JNK inhibitor, SP600125, reversed DHA-induced cell death in suspended HUVECs, suggesting that the JNK pathway may mediate DHA-induced endothelial cell anoikis. The data from the present study indicates a novel mechanism for understanding the anti-angiogenic effects of DHA, which may be used as a component for chemotherapy.

No MeSH data available.


JNK inhibitor, SP600125, reverses the viability and apoptosis of suspended HUVECs induced by DHA. (A) Representative immunoblots of p-JNK and JNK in suspended HUVECs treated with DHA and SP600125. (B) Percentage of viable cells from suspended HUVECs treated with DHA and SP600125; n=4. (C) Representative images of flow cytometry analyses of Annexin V/PI-staining in suspended HUVECs treated with DHA and SP600125. DHA, dihydroartemisinin; JNK, c-Jun N-terminal kinase; p-JNK, phosphorylated-JNK; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; HUVEC, human umbilical vein endothelial cell; n.s., non-significant; PI, propidium iodide; FITC, fluorescein isothiocyanate.
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f3-ol-0-0-4870: JNK inhibitor, SP600125, reverses the viability and apoptosis of suspended HUVECs induced by DHA. (A) Representative immunoblots of p-JNK and JNK in suspended HUVECs treated with DHA and SP600125. (B) Percentage of viable cells from suspended HUVECs treated with DHA and SP600125; n=4. (C) Representative images of flow cytometry analyses of Annexin V/PI-staining in suspended HUVECs treated with DHA and SP600125. DHA, dihydroartemisinin; JNK, c-Jun N-terminal kinase; p-JNK, phosphorylated-JNK; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; HUVEC, human umbilical vein endothelial cell; n.s., non-significant; PI, propidium iodide; FITC, fluorescein isothiocyanate.

Mentions: SP600125 is a cell-permeable and selective inhibitor of the JNK pathway (20). To further verify the role of the JNK signaling pathway in the cell death of suspended HUVECs, 10 µM SP600125 was applied to suspended HUVECs for 1 h prior to DHA treatment. Fig. 3A indicates that SP600125 successfully prevented the increase of p-JNK. SP600125 treatment abrogated the decrease of viable cells in suspended HUVECs treated with DHA (74.6±4.5% vs. 78.9±6.6%; P=0.19) (Fig. 3B). SP600125 also attenuated DHA-induced apoptosis in suspended HUVECs (28.6±2.5% vs. 30.3±4.9%; P=0.12) (Fig. 3C). These results suggest that JNK signaling pathway mediates DHA induced anoikis in endothelial cells.


Dihydroartemisinin induces endothelial cell anoikis through the activation of the JNK signaling pathway
JNK inhibitor, SP600125, reverses the viability and apoptosis of suspended HUVECs induced by DHA. (A) Representative immunoblots of p-JNK and JNK in suspended HUVECs treated with DHA and SP600125. (B) Percentage of viable cells from suspended HUVECs treated with DHA and SP600125; n=4. (C) Representative images of flow cytometry analyses of Annexin V/PI-staining in suspended HUVECs treated with DHA and SP600125. DHA, dihydroartemisinin; JNK, c-Jun N-terminal kinase; p-JNK, phosphorylated-JNK; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; HUVEC, human umbilical vein endothelial cell; n.s., non-significant; PI, propidium iodide; FITC, fluorescein isothiocyanate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4998146&req=5

f3-ol-0-0-4870: JNK inhibitor, SP600125, reverses the viability and apoptosis of suspended HUVECs induced by DHA. (A) Representative immunoblots of p-JNK and JNK in suspended HUVECs treated with DHA and SP600125. (B) Percentage of viable cells from suspended HUVECs treated with DHA and SP600125; n=4. (C) Representative images of flow cytometry analyses of Annexin V/PI-staining in suspended HUVECs treated with DHA and SP600125. DHA, dihydroartemisinin; JNK, c-Jun N-terminal kinase; p-JNK, phosphorylated-JNK; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; HUVEC, human umbilical vein endothelial cell; n.s., non-significant; PI, propidium iodide; FITC, fluorescein isothiocyanate.
Mentions: SP600125 is a cell-permeable and selective inhibitor of the JNK pathway (20). To further verify the role of the JNK signaling pathway in the cell death of suspended HUVECs, 10 µM SP600125 was applied to suspended HUVECs for 1 h prior to DHA treatment. Fig. 3A indicates that SP600125 successfully prevented the increase of p-JNK. SP600125 treatment abrogated the decrease of viable cells in suspended HUVECs treated with DHA (74.6±4.5% vs. 78.9±6.6%; P=0.19) (Fig. 3B). SP600125 also attenuated DHA-induced apoptosis in suspended HUVECs (28.6±2.5% vs. 30.3±4.9%; P=0.12) (Fig. 3C). These results suggest that JNK signaling pathway mediates DHA induced anoikis in endothelial cells.

View Article: PubMed Central - PubMed

ABSTRACT

Angiogenesis is required for the growth and metastasis of solid tumors. The anti-malarial agent dihydroartemisinin (DHA) demonstrates potent anti-angiogenic activity, but the underlying molecular mechanisms are not yet fully understood. During the process of angiogenesis, endothelial cells migrating from existing capillaries may undergo programmed cell death after detaching from the extracellular matrix, a process that is defined as anchorage-dependent apoptosis or anoikis. In the present study, DHA-induced cell death was compared in human umbilical vein endothelial cells (HUVECs) cultured in suspension and attached to culture plates. In suspended HUVECs, the cell viability was decreased and apoptosis was increased with the treatment of 50 µM DHA for 5 h, while the same treatment did not affect the attached HUVECs. In addition, 50 µM DHA increased the phosphorylation of c-Jun N-terminal kinase (JNK) in suspended HUVECs, but not in attached HUVECs, for up to 5 h of treatment. The JNK inhibitor, SP600125, reversed DHA-induced cell death in suspended HUVECs, suggesting that the JNK pathway may mediate DHA-induced endothelial cell anoikis. The data from the present study indicates a novel mechanism for understanding the anti-angiogenic effects of DHA, which may be used as a component for chemotherapy.

No MeSH data available.