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Anti-tumour activity of tivozanib, a pan-inhibitor of VEGF receptors, in therapy-resistant ovarian carcinoma cells

View Article: PubMed Central - PubMed

ABSTRACT

Epithelial ovarian cancer (EOC) is the most fatal gynaecological malignancy. Despite initial therapeutic response, the majority of advanced-stage patients relapse and succumb to chemoresistant disease. Overcoming drug resistance is the key to successful treatment of EOC. Members of vascular endothelial growth factor (VEGF) family are overexpressed in EOC and play key roles in its malignant progression though their contribution in development of the chemoresistant disease remains elusive. Here we show that expression of the VEGF family is higher in therapy-resistant EOC cells compared to sensitive ones. Overexpression of VEGFR2 correlated with resistance to cisplatin and combination with VEGFR2-inhibitor apatinib synergistically increased cisplatin sensitivity. Tivozanib, a pan-inhibitor of VEGF receptors, reduced proliferation of the chemoresistant EOC cells through induction of G2/M cell cycle arrest and apoptotic cell death. Tivozanib decreased invasive potential of these cells, concomitant with reduction of intercellular adhesion molecule-1 (ICAM-1) and diminishing the enzymatic activity of urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-2 (MMP-2). Moreover, tivozanib synergistically enhanced anti-tumour effects of EGFR-directed therapies including erlotinib. These findings suggest that the VEGF pathway has potential as a therapeutic target in therapy-resistant EOC and VEGFR blockade by tivozanib may yield stronger anti-tumour efficacy and circumvent resistance to EGFR-directed therapies.

No MeSH data available.


Related in: MedlinePlus

Tivozanib induces G2/M cell cycle arrest and apoptosis.(A) Following treatment with tivozanib for 48 h, the cell pellets were fixed and incubated with propidium iodide to analyse the cell cycle distribution on a flow cytometer. The concentrations of tivozanib were 2, 5, 10 and 20 μM. The graphs are representative of three independent experiments with similar results. (B) Protein lysates from tivozanib-treated cells were subjected to Western blotting and probed with the indicated antibodies. β-actin was used as the loading control. The concentrations of tivozanib were 5, 10 and 20 μM. The blots are representative of three independent experiments with similar outcomes. (C) The cells were treated with tivozanib for 48 h then total RNA was harvested for qRT-PCR analysis. Gene expression levels were normalized to HPRT1. Data are given as mean ± SD. Statistically significant values of *p < 0.05, **p < 0.01, and ***p < 0.001 were determined compared with the control. IL, interleukin; CDKN1A, cyclin-dependent kinase inhibitor 1 A; CCNB1, cyclin B1; CDK, cyclin-dependent kinase; GADD45A, growth arrest and DNA damage inducible alpha; CHEK, checkpoint kinase; CDC25, cell division cycle 25; CCNA2, cyclin A2; MYT1, myelin transcription factor 1; SFN, stratifin.
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f3: Tivozanib induces G2/M cell cycle arrest and apoptosis.(A) Following treatment with tivozanib for 48 h, the cell pellets were fixed and incubated with propidium iodide to analyse the cell cycle distribution on a flow cytometer. The concentrations of tivozanib were 2, 5, 10 and 20 μM. The graphs are representative of three independent experiments with similar results. (B) Protein lysates from tivozanib-treated cells were subjected to Western blotting and probed with the indicated antibodies. β-actin was used as the loading control. The concentrations of tivozanib were 5, 10 and 20 μM. The blots are representative of three independent experiments with similar outcomes. (C) The cells were treated with tivozanib for 48 h then total RNA was harvested for qRT-PCR analysis. Gene expression levels were normalized to HPRT1. Data are given as mean ± SD. Statistically significant values of *p < 0.05, **p < 0.01, and ***p < 0.001 were determined compared with the control. IL, interleukin; CDKN1A, cyclin-dependent kinase inhibitor 1 A; CCNB1, cyclin B1; CDK, cyclin-dependent kinase; GADD45A, growth arrest and DNA damage inducible alpha; CHEK, checkpoint kinase; CDC25, cell division cycle 25; CCNA2, cyclin A2; MYT1, myelin transcription factor 1; SFN, stratifin.

Mentions: Due to the anti-proliferative effects of tivozanib, we asked if tivozanib inhibits cell cycle progression or affects apoptosis. In OVCAR3 and A2780CP cells, tivozanib increased the percentage of cells in G2/M phase while decreasing the G1/S fraction. Moreover, a small number of cells underwent apoptotic cell death, as indicated by appearance of a sub- G0/G1 population. SKOV3 cells treated with tivozanib displayed an increase in the G2/M population (Fig. 3A).


Anti-tumour activity of tivozanib, a pan-inhibitor of VEGF receptors, in therapy-resistant ovarian carcinoma cells
Tivozanib induces G2/M cell cycle arrest and apoptosis.(A) Following treatment with tivozanib for 48 h, the cell pellets were fixed and incubated with propidium iodide to analyse the cell cycle distribution on a flow cytometer. The concentrations of tivozanib were 2, 5, 10 and 20 μM. The graphs are representative of three independent experiments with similar results. (B) Protein lysates from tivozanib-treated cells were subjected to Western blotting and probed with the indicated antibodies. β-actin was used as the loading control. The concentrations of tivozanib were 5, 10 and 20 μM. The blots are representative of three independent experiments with similar outcomes. (C) The cells were treated with tivozanib for 48 h then total RNA was harvested for qRT-PCR analysis. Gene expression levels were normalized to HPRT1. Data are given as mean ± SD. Statistically significant values of *p < 0.05, **p < 0.01, and ***p < 0.001 were determined compared with the control. IL, interleukin; CDKN1A, cyclin-dependent kinase inhibitor 1 A; CCNB1, cyclin B1; CDK, cyclin-dependent kinase; GADD45A, growth arrest and DNA damage inducible alpha; CHEK, checkpoint kinase; CDC25, cell division cycle 25; CCNA2, cyclin A2; MYT1, myelin transcription factor 1; SFN, stratifin.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC5382685&req=5

f3: Tivozanib induces G2/M cell cycle arrest and apoptosis.(A) Following treatment with tivozanib for 48 h, the cell pellets were fixed and incubated with propidium iodide to analyse the cell cycle distribution on a flow cytometer. The concentrations of tivozanib were 2, 5, 10 and 20 μM. The graphs are representative of three independent experiments with similar results. (B) Protein lysates from tivozanib-treated cells were subjected to Western blotting and probed with the indicated antibodies. β-actin was used as the loading control. The concentrations of tivozanib were 5, 10 and 20 μM. The blots are representative of three independent experiments with similar outcomes. (C) The cells were treated with tivozanib for 48 h then total RNA was harvested for qRT-PCR analysis. Gene expression levels were normalized to HPRT1. Data are given as mean ± SD. Statistically significant values of *p < 0.05, **p < 0.01, and ***p < 0.001 were determined compared with the control. IL, interleukin; CDKN1A, cyclin-dependent kinase inhibitor 1 A; CCNB1, cyclin B1; CDK, cyclin-dependent kinase; GADD45A, growth arrest and DNA damage inducible alpha; CHEK, checkpoint kinase; CDC25, cell division cycle 25; CCNA2, cyclin A2; MYT1, myelin transcription factor 1; SFN, stratifin.
Mentions: Due to the anti-proliferative effects of tivozanib, we asked if tivozanib inhibits cell cycle progression or affects apoptosis. In OVCAR3 and A2780CP cells, tivozanib increased the percentage of cells in G2/M phase while decreasing the G1/S fraction. Moreover, a small number of cells underwent apoptotic cell death, as indicated by appearance of a sub- G0/G1 population. SKOV3 cells treated with tivozanib displayed an increase in the G2/M population (Fig. 3A).

View Article: PubMed Central - PubMed

ABSTRACT

Epithelial ovarian cancer (EOC) is the most fatal gynaecological malignancy. Despite initial therapeutic response, the majority of advanced-stage patients relapse and succumb to chemoresistant disease. Overcoming drug resistance is the key to successful treatment of EOC. Members of vascular endothelial growth factor (VEGF) family are overexpressed in EOC and play key roles in its malignant progression though their contribution in development of the chemoresistant disease remains elusive. Here we show that expression of the VEGF family is higher in therapy-resistant EOC cells compared to sensitive ones. Overexpression of VEGFR2 correlated with resistance to cisplatin and combination with VEGFR2-inhibitor apatinib synergistically increased cisplatin sensitivity. Tivozanib, a pan-inhibitor of VEGF receptors, reduced proliferation of the chemoresistant EOC cells through induction of G2/M cell cycle arrest and apoptotic cell death. Tivozanib decreased invasive potential of these cells, concomitant with reduction of intercellular adhesion molecule-1 (ICAM-1) and diminishing the enzymatic activity of urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-2 (MMP-2). Moreover, tivozanib synergistically enhanced anti-tumour effects of EGFR-directed therapies including erlotinib. These findings suggest that the VEGF pathway has potential as a therapeutic target in therapy-resistant EOC and VEGFR blockade by tivozanib may yield stronger anti-tumour efficacy and circumvent resistance to EGFR-directed therapies.

No MeSH data available.


Related in: MedlinePlus