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Ad-p53 enhances the sensitivity of triple-negative breast cancer MDA-MB-468 cells to the EGFR inhibitor gefitinib.

Wang X, Song H, Yu Q, Liu Q, Wang L, Liu Z, Yu Z - Oncol. Rep. (2014)

Bottom Line: Neither endocrine nor anti-HER2 molecular targeting treatment yield promising results.Western blot analysis revealed that Ad-p53 and gefitinib in combination significantly downregulated the phosphorylation of protein kinase B (p-Akt) and upregulated caspase-9 and cleaved caspase-3, while there were minimal effects on the expression of extracellular signal-regulated kinase (ERK) and phosphorylation of ERK (p-ERK).These results suggest that Ad-p53 may block the PI3K/Akt pathway rather than the Raf/MEK/ERK pathway.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Shandong Cancer Hospital, Jinan, Shandong 250117, P.R. China.

ABSTRACT
Triple-negative breast cancer (TNBC) accounts for 20% of all molecular subtypes of breast cancer. Neither endocrine nor anti-HER2 molecular targeting treatment yield promising results. At present, epidermal growth factor receptor (EGFR) inhibitor, as a single agent, is unable to obtain encouraging results in the treatment of TNBC, even though most of these tumors overexpress EGFR. In the present study, we used recombinant human p53 adenovirus (Ad-p53) and EGFR inhibitor gefitinib to treat the TNBC cell line MDA-MB-468. The combined treatment of gefitinib and Ad-p53 synergistically inhibited the proliferation of MDA-MB-468 cells; it restrained colony formation, enhanced cellular apoptosis and arrested the cell cycle in vitro, and decreased tumor burden of xenografts in nude mice. Western blot analysis revealed that Ad-p53 and gefitinib in combination significantly downregulated the phosphorylation of protein kinase B (p-Akt) and upregulated caspase-9 and cleaved caspase-3, while there were minimal effects on the expression of extracellular signal-regulated kinase (ERK) and phosphorylation of ERK (p-ERK). These results suggest that Ad-p53 may block the PI3K/Akt pathway rather than the Raf/MEK/ERK pathway. Importantly, wild-type p53 was able to reverse the drug resistance of MDA-MB-468 cells to gefitinib through inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. The apoptotic activity induced by this combined treatment may be regulated by caspase cascade-dependent activation.

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Related in: MedlinePlus

Ad-p53 infection enhances G2/M arrest induced by gefitinib. MDA-MB-468 cells were treated with 3 μM of gefitinib alone, MOI of 100 of Ad-p53 alone or in combination. After 48 h, cell cycle distribution was analyzed by flow cytometry at the indicated time. The graph is based on three independent measurements with similar results. Ad-p53, recombinant human p53 adenovirus; MOI, multiplicity of infection.
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f4-or-33-02-0526: Ad-p53 infection enhances G2/M arrest induced by gefitinib. MDA-MB-468 cells were treated with 3 μM of gefitinib alone, MOI of 100 of Ad-p53 alone or in combination. After 48 h, cell cycle distribution was analyzed by flow cytometry at the indicated time. The graph is based on three independent measurements with similar results. Ad-p53, recombinant human p53 adenovirus; MOI, multiplicity of infection.

Mentions: MDA-MB-468 cells were treated with either drug alone or in combination with Ad-p53 for 48 h. According to flow cytometry, the apoptosis rate in the Ad-p53, gefitinib, combination and vehicle-treated group was 17.4, 20.5, 32.6 and 8.5%, respectively. Treatment with Ad-p53 or gefitinib alone slightly induced cellular apoptosis (Fig. 3). The combined treatment increased cellular apoptosis to 4-fold when compared with the vehicle-treated control (Fig. 3). As shown in Fig. 4, gefitinib induced G2/M phase arrest from 21.9 to 45.4% compared to the vehicle-treated groups; G2/M phase increased to no more than 31.5% after exposure to Ad-p53. In comparison, when the combined treatment was performed, G2/M arrest was enhanced evidently from 21.9 to 65.3%.


Ad-p53 enhances the sensitivity of triple-negative breast cancer MDA-MB-468 cells to the EGFR inhibitor gefitinib.

Wang X, Song H, Yu Q, Liu Q, Wang L, Liu Z, Yu Z - Oncol. Rep. (2014)

Ad-p53 infection enhances G2/M arrest induced by gefitinib. MDA-MB-468 cells were treated with 3 μM of gefitinib alone, MOI of 100 of Ad-p53 alone or in combination. After 48 h, cell cycle distribution was analyzed by flow cytometry at the indicated time. The graph is based on three independent measurements with similar results. Ad-p53, recombinant human p53 adenovirus; MOI, multiplicity of infection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306269&req=5

f4-or-33-02-0526: Ad-p53 infection enhances G2/M arrest induced by gefitinib. MDA-MB-468 cells were treated with 3 μM of gefitinib alone, MOI of 100 of Ad-p53 alone or in combination. After 48 h, cell cycle distribution was analyzed by flow cytometry at the indicated time. The graph is based on three independent measurements with similar results. Ad-p53, recombinant human p53 adenovirus; MOI, multiplicity of infection.
Mentions: MDA-MB-468 cells were treated with either drug alone or in combination with Ad-p53 for 48 h. According to flow cytometry, the apoptosis rate in the Ad-p53, gefitinib, combination and vehicle-treated group was 17.4, 20.5, 32.6 and 8.5%, respectively. Treatment with Ad-p53 or gefitinib alone slightly induced cellular apoptosis (Fig. 3). The combined treatment increased cellular apoptosis to 4-fold when compared with the vehicle-treated control (Fig. 3). As shown in Fig. 4, gefitinib induced G2/M phase arrest from 21.9 to 45.4% compared to the vehicle-treated groups; G2/M phase increased to no more than 31.5% after exposure to Ad-p53. In comparison, when the combined treatment was performed, G2/M arrest was enhanced evidently from 21.9 to 65.3%.

Bottom Line: Neither endocrine nor anti-HER2 molecular targeting treatment yield promising results.Western blot analysis revealed that Ad-p53 and gefitinib in combination significantly downregulated the phosphorylation of protein kinase B (p-Akt) and upregulated caspase-9 and cleaved caspase-3, while there were minimal effects on the expression of extracellular signal-regulated kinase (ERK) and phosphorylation of ERK (p-ERK).These results suggest that Ad-p53 may block the PI3K/Akt pathway rather than the Raf/MEK/ERK pathway.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Shandong Cancer Hospital, Jinan, Shandong 250117, P.R. China.

ABSTRACT
Triple-negative breast cancer (TNBC) accounts for 20% of all molecular subtypes of breast cancer. Neither endocrine nor anti-HER2 molecular targeting treatment yield promising results. At present, epidermal growth factor receptor (EGFR) inhibitor, as a single agent, is unable to obtain encouraging results in the treatment of TNBC, even though most of these tumors overexpress EGFR. In the present study, we used recombinant human p53 adenovirus (Ad-p53) and EGFR inhibitor gefitinib to treat the TNBC cell line MDA-MB-468. The combined treatment of gefitinib and Ad-p53 synergistically inhibited the proliferation of MDA-MB-468 cells; it restrained colony formation, enhanced cellular apoptosis and arrested the cell cycle in vitro, and decreased tumor burden of xenografts in nude mice. Western blot analysis revealed that Ad-p53 and gefitinib in combination significantly downregulated the phosphorylation of protein kinase B (p-Akt) and upregulated caspase-9 and cleaved caspase-3, while there were minimal effects on the expression of extracellular signal-regulated kinase (ERK) and phosphorylation of ERK (p-ERK). These results suggest that Ad-p53 may block the PI3K/Akt pathway rather than the Raf/MEK/ERK pathway. Importantly, wild-type p53 was able to reverse the drug resistance of MDA-MB-468 cells to gefitinib through inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. The apoptotic activity induced by this combined treatment may be regulated by caspase cascade-dependent activation.

Show MeSH
Related in: MedlinePlus