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CDK5 Regulates Paclitaxel Sensitivity in Ovarian Cancer Cells by Modulating AKT Activation, p21Cip1- and p27Kip1-Mediated G1 Cell Cycle Arrest and Apoptosis.

Zhang S, Lu Z, Mao W, Ahmed AA, Yang H, Zhou J, Jennings N, Rodriguez-Aguayo C, Lopez-Berestein G, Miranda R, Qiao W, Baladandayuthapani V, Li Z, Sood AK, Liu J, Le XF, Bast RC - PLoS ONE (2015)

Bottom Line: Cyclin-dependent kinase 5 (CDK5) is a cytoplasmic serine/ threonine kinase.In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1) as well as TP53-dependent transcriptional induction of p21(Cip1) in wild type TP53 cancer cells.CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis.

View Article: PubMed Central - PubMed

Affiliation: Departments of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America; Department of General Surgery, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, China.

ABSTRACT
Cyclin-dependent kinase 5 (CDK5) is a cytoplasmic serine/ threonine kinase. Knockdown of CDK5 enhances paclitaxel sensitivity in human ovarian cancer cells. This study explores the mechanisms by which CDK5 regulates paclitaxel sensitivity in human ovarian cancers. Multiple ovarian cancer cell lines and xenografts were treated with CDK5 small interfering RNA (siRNA) with or without paclitaxel to examine the effect on cancer cell viability, cell cycle arrest and tumor growth. CDK5 protein was measured by immunohistochemical staining of an ovarian cancer tissue microarray to correlate CDK5 expression with overall patient survival. Knockdown of CDK5 with siRNAs inhibits activation of AKT which significantly correlates with decreased cell growth and enhanced paclitaxel sensitivity in ovarian cancer cell lines. In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1) as well as TP53-dependent transcriptional induction of p21(Cip1) in wild type TP53 cancer cells. Treatment of HEYA8 and A2780 wild type TP53 xenografts in nu/nu mice with CDK5 siRNA and paclitaxel produced significantly greater growth inhibition than either treatment alone. Increased expression of CDK5 in human ovarian cancers correlates inversely with overall survival. CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis. CDK5 inhibition can potentiate paclitaxel activity in human ovarian cancer cells.

No MeSH data available.


Related in: MedlinePlus

CDK5 siRNA inhibits cell growth and enhances paclitaxel sensitivity in multiple ovarian cancer cell lines.(A) Short term cell growth assay. Hey and A2780 cells in 96-well plates were reverse transfected with control siRNA or CDK5 siRNA (Dhamarcon) for 24 h and treated with 5 nM paclitaxel (Pac) or diluent (Control) for an additional 48 h. A crystal violet cell proliferation assay was used to measure the growth of cells. (B) Clonogenic and cell growth assays. HEY and A2780 cells were transfected with control siRNA or CDK5 siRNA for 24 h, and then cells were treated with diluent (Control) or 3 nM paclitaxel (Pac) for 14 days (clonogenic assay) or cells were treated with multiple concentrations of paclitaxel (Pac) or diluent (Control) for an additional 48 h (cell growth assays). The IC50s of paclitaxel with or with CDK5 siRNA treatment in Hey and A2780 cells were calculated in GraphPad.
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pone.0131833.g001: CDK5 siRNA inhibits cell growth and enhances paclitaxel sensitivity in multiple ovarian cancer cell lines.(A) Short term cell growth assay. Hey and A2780 cells in 96-well plates were reverse transfected with control siRNA or CDK5 siRNA (Dhamarcon) for 24 h and treated with 5 nM paclitaxel (Pac) or diluent (Control) for an additional 48 h. A crystal violet cell proliferation assay was used to measure the growth of cells. (B) Clonogenic and cell growth assays. HEY and A2780 cells were transfected with control siRNA or CDK5 siRNA for 24 h, and then cells were treated with diluent (Control) or 3 nM paclitaxel (Pac) for 14 days (clonogenic assay) or cells were treated with multiple concentrations of paclitaxel (Pac) or diluent (Control) for an additional 48 h (cell growth assays). The IC50s of paclitaxel with or with CDK5 siRNA treatment in Hey and A2780 cells were calculated in GraphPad.

Mentions: While knockdown of CDK5 with siRNA could alter cell growth and paclitaxel sensitivity in ovarian cancer cell lines with mutant TP53 (EFO21, EFO27, IGROV1, CAOV3, OAW42 and ES-2, SKOv3 and OC316) (Fig 1A), the most marked effects were observed in two ovarian cancer cell lines with wild type TP53 (HEY and A2780) (Fig 1A and 1B). Silencing CDK5 significantly reduced the IC50 of paclitaxel in Hey and A2780 cells (Fig 1B). Forced expression of CDK5 enhanced growth and decreased sensitivity to paclitaxel in HEY cells (S1 Fig). The CDK inhibitor roscovitine also inhibited CDK5 activity and cell growth in Hey cells as did CDK5 siRNA in HEY and A2780 cells (S1 Fig). In addition to inhibiting growth in short term assays, knockdown of CDK5 significantly inhibited colony formation and enhanced sensitivity to paclitaxel in HEY and A2780 cells (Fig 1B and S2 Fig).


CDK5 Regulates Paclitaxel Sensitivity in Ovarian Cancer Cells by Modulating AKT Activation, p21Cip1- and p27Kip1-Mediated G1 Cell Cycle Arrest and Apoptosis.

Zhang S, Lu Z, Mao W, Ahmed AA, Yang H, Zhou J, Jennings N, Rodriguez-Aguayo C, Lopez-Berestein G, Miranda R, Qiao W, Baladandayuthapani V, Li Z, Sood AK, Liu J, Le XF, Bast RC - PLoS ONE (2015)

CDK5 siRNA inhibits cell growth and enhances paclitaxel sensitivity in multiple ovarian cancer cell lines.(A) Short term cell growth assay. Hey and A2780 cells in 96-well plates were reverse transfected with control siRNA or CDK5 siRNA (Dhamarcon) for 24 h and treated with 5 nM paclitaxel (Pac) or diluent (Control) for an additional 48 h. A crystal violet cell proliferation assay was used to measure the growth of cells. (B) Clonogenic and cell growth assays. HEY and A2780 cells were transfected with control siRNA or CDK5 siRNA for 24 h, and then cells were treated with diluent (Control) or 3 nM paclitaxel (Pac) for 14 days (clonogenic assay) or cells were treated with multiple concentrations of paclitaxel (Pac) or diluent (Control) for an additional 48 h (cell growth assays). The IC50s of paclitaxel with or with CDK5 siRNA treatment in Hey and A2780 cells were calculated in GraphPad.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4492679&req=5

pone.0131833.g001: CDK5 siRNA inhibits cell growth and enhances paclitaxel sensitivity in multiple ovarian cancer cell lines.(A) Short term cell growth assay. Hey and A2780 cells in 96-well plates were reverse transfected with control siRNA or CDK5 siRNA (Dhamarcon) for 24 h and treated with 5 nM paclitaxel (Pac) or diluent (Control) for an additional 48 h. A crystal violet cell proliferation assay was used to measure the growth of cells. (B) Clonogenic and cell growth assays. HEY and A2780 cells were transfected with control siRNA or CDK5 siRNA for 24 h, and then cells were treated with diluent (Control) or 3 nM paclitaxel (Pac) for 14 days (clonogenic assay) or cells were treated with multiple concentrations of paclitaxel (Pac) or diluent (Control) for an additional 48 h (cell growth assays). The IC50s of paclitaxel with or with CDK5 siRNA treatment in Hey and A2780 cells were calculated in GraphPad.
Mentions: While knockdown of CDK5 with siRNA could alter cell growth and paclitaxel sensitivity in ovarian cancer cell lines with mutant TP53 (EFO21, EFO27, IGROV1, CAOV3, OAW42 and ES-2, SKOv3 and OC316) (Fig 1A), the most marked effects were observed in two ovarian cancer cell lines with wild type TP53 (HEY and A2780) (Fig 1A and 1B). Silencing CDK5 significantly reduced the IC50 of paclitaxel in Hey and A2780 cells (Fig 1B). Forced expression of CDK5 enhanced growth and decreased sensitivity to paclitaxel in HEY cells (S1 Fig). The CDK inhibitor roscovitine also inhibited CDK5 activity and cell growth in Hey cells as did CDK5 siRNA in HEY and A2780 cells (S1 Fig). In addition to inhibiting growth in short term assays, knockdown of CDK5 significantly inhibited colony formation and enhanced sensitivity to paclitaxel in HEY and A2780 cells (Fig 1B and S2 Fig).

Bottom Line: Cyclin-dependent kinase 5 (CDK5) is a cytoplasmic serine/ threonine kinase.In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1) as well as TP53-dependent transcriptional induction of p21(Cip1) in wild type TP53 cancer cells.CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis.

View Article: PubMed Central - PubMed

Affiliation: Departments of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America; Department of General Surgery, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, China.

ABSTRACT
Cyclin-dependent kinase 5 (CDK5) is a cytoplasmic serine/ threonine kinase. Knockdown of CDK5 enhances paclitaxel sensitivity in human ovarian cancer cells. This study explores the mechanisms by which CDK5 regulates paclitaxel sensitivity in human ovarian cancers. Multiple ovarian cancer cell lines and xenografts were treated with CDK5 small interfering RNA (siRNA) with or without paclitaxel to examine the effect on cancer cell viability, cell cycle arrest and tumor growth. CDK5 protein was measured by immunohistochemical staining of an ovarian cancer tissue microarray to correlate CDK5 expression with overall patient survival. Knockdown of CDK5 with siRNAs inhibits activation of AKT which significantly correlates with decreased cell growth and enhanced paclitaxel sensitivity in ovarian cancer cell lines. In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1) as well as TP53-dependent transcriptional induction of p21(Cip1) in wild type TP53 cancer cells. Treatment of HEYA8 and A2780 wild type TP53 xenografts in nu/nu mice with CDK5 siRNA and paclitaxel produced significantly greater growth inhibition than either treatment alone. Increased expression of CDK5 in human ovarian cancers correlates inversely with overall survival. CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis. CDK5 inhibition can potentiate paclitaxel activity in human ovarian cancer cells.

No MeSH data available.


Related in: MedlinePlus