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Ritonavir blocks AKT signaling, activates apoptosis and inhibits migration and invasion in ovarian cancer cells.

Kumar S, Bryant CS, Chamala S, Qazi A, Seward S, Pal J, Steffes CP, Weaver DW, Morris R, Malone JM, Shammas MA, Prasad M, Batchu RB - Mol. Cancer (2009)

Bottom Line: Over a 3 day period with 20 muM ritonavir resulted in the cell death of over 60% for MDAH-2774 compared with 55% in case of SKOV-3 cell line.These results indicate that the addition of the AKT inhibitor may increase the therapeutic efficacy of ritonavir.This would reduce risks, limit the costs and decrease the time needed to bring the drug from bench to bedside.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Surgical Oncology & Developmental Therapeutics, Department of Surgery, Wayne State University, Detroit, MI, USA. skumar@med.wayne.edu

ABSTRACT

Background: Ovarian cancer is the leading cause of mortality from gynecological malignancies, often undetectable in early stages. The difficulty of detecting the disease in its early stages and the propensity of ovarian cancer cells to develop resistance to known chemotherapeutic treatments dramatically decreases the 5-year survival rate. Chemotherapy with paclitaxel after surgery increases median survival only by 2 to 3 years in stage IV disease highlights the need for more effective drugs. The human immunodeficiency virus (HIV) infection is characterized by increased risk of several solid tumors due to its inherent nature of weakening of immune system. Recent observations point to a lower incidence of some cancers in patients treated with protease inhibitor (PI) cocktail treatment known as HAART (Highly Active Anti-Retroviral Therapy).

Results: Here we show that ritonavir, a HIV protease inhibitor effectively induced cell cycle arrest and apoptosis in ovarian cell lines MDH-2774 and SKOV-3 in a dose dependent manner. Over a 3 day period with 20 muM ritonavir resulted in the cell death of over 60% for MDAH-2774 compared with 55% in case of SKOV-3 cell line. Ritonavir caused G1 cell cycle arrest of the ovarian cancer cells, mediated by down modulating levels of RB phosphorylation and depleting the G1 cyclins, cyclin-dependent kinase and increasing their inhibitors as determined by gene profile analysis. Interestingly, the treatment of ritonavir decreased the amount of phosphorylated AKT in a dose-dependent manner. Furthermore, inhibition of AKT by specific siRNA synergistically increased the efficacy of the ritonavir-induced apoptosis. These results indicate that the addition of the AKT inhibitor may increase the therapeutic efficacy of ritonavir.

Conclusion: Our results demonstrate a potential use of ritonavir for ovarian cancer with additive effects in conjunction with conventional chemotherapeutic regimens. Since ritonavir is clinically approved for human use for HIV, drug repositioning for ovarian cancer could accelerate the process of traditional drug development. This would reduce risks, limit the costs and decrease the time needed to bring the drug from bench to bedside.

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Related in: MedlinePlus

Effect of ritonavir on DNA synthesis of MDAH-2774 cells. MDAH-2774 and normal human fibroblasts were seeded at 106 cells and grown serum-free medium for 48 h for cell cycle synchronization. The cells were then treated with either vehicle DMSO (A) or 5 μM ritonavir (B) or 20 μM ritonavir (C). Cells were further incubated in presence of serum for 24 h followed by fixation, staining and cytometric analysis using Cell cycle phase determination kit (Cayman chemical company, Ann Arbor, MI).
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Figure 4: Effect of ritonavir on DNA synthesis of MDAH-2774 cells. MDAH-2774 and normal human fibroblasts were seeded at 106 cells and grown serum-free medium for 48 h for cell cycle synchronization. The cells were then treated with either vehicle DMSO (A) or 5 μM ritonavir (B) or 20 μM ritonavir (C). Cells were further incubated in presence of serum for 24 h followed by fixation, staining and cytometric analysis using Cell cycle phase determination kit (Cayman chemical company, Ann Arbor, MI).

Mentions: Ritonavir induced G2/M arrest in a dose-dependent manner (Fig. 4A, B and 4C) in MDAH-2774 but not in normal human fibroblasts (data not shown). Remarkably, the proportion of cells in the G0/G1 phase arrest increased from 48.8% to 89.2% while S phase of cells decreased from 28.7% to 3.3% with the treatment of 20 μM ritonvir within 24 hrs (Fig. 4A, B and 4C). Further we observed dose dependent inhibition in the S phase cells indicative of the inhibition of DNA synthesis in MDAH-2774 cells in dose dependent manner.


Ritonavir blocks AKT signaling, activates apoptosis and inhibits migration and invasion in ovarian cancer cells.

Kumar S, Bryant CS, Chamala S, Qazi A, Seward S, Pal J, Steffes CP, Weaver DW, Morris R, Malone JM, Shammas MA, Prasad M, Batchu RB - Mol. Cancer (2009)

Effect of ritonavir on DNA synthesis of MDAH-2774 cells. MDAH-2774 and normal human fibroblasts were seeded at 106 cells and grown serum-free medium for 48 h for cell cycle synchronization. The cells were then treated with either vehicle DMSO (A) or 5 μM ritonavir (B) or 20 μM ritonavir (C). Cells were further incubated in presence of serum for 24 h followed by fixation, staining and cytometric analysis using Cell cycle phase determination kit (Cayman chemical company, Ann Arbor, MI).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2691728&req=5

Figure 4: Effect of ritonavir on DNA synthesis of MDAH-2774 cells. MDAH-2774 and normal human fibroblasts were seeded at 106 cells and grown serum-free medium for 48 h for cell cycle synchronization. The cells were then treated with either vehicle DMSO (A) or 5 μM ritonavir (B) or 20 μM ritonavir (C). Cells were further incubated in presence of serum for 24 h followed by fixation, staining and cytometric analysis using Cell cycle phase determination kit (Cayman chemical company, Ann Arbor, MI).
Mentions: Ritonavir induced G2/M arrest in a dose-dependent manner (Fig. 4A, B and 4C) in MDAH-2774 but not in normal human fibroblasts (data not shown). Remarkably, the proportion of cells in the G0/G1 phase arrest increased from 48.8% to 89.2% while S phase of cells decreased from 28.7% to 3.3% with the treatment of 20 μM ritonvir within 24 hrs (Fig. 4A, B and 4C). Further we observed dose dependent inhibition in the S phase cells indicative of the inhibition of DNA synthesis in MDAH-2774 cells in dose dependent manner.

Bottom Line: Over a 3 day period with 20 muM ritonavir resulted in the cell death of over 60% for MDAH-2774 compared with 55% in case of SKOV-3 cell line.These results indicate that the addition of the AKT inhibitor may increase the therapeutic efficacy of ritonavir.This would reduce risks, limit the costs and decrease the time needed to bring the drug from bench to bedside.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Surgical Oncology & Developmental Therapeutics, Department of Surgery, Wayne State University, Detroit, MI, USA. skumar@med.wayne.edu

ABSTRACT

Background: Ovarian cancer is the leading cause of mortality from gynecological malignancies, often undetectable in early stages. The difficulty of detecting the disease in its early stages and the propensity of ovarian cancer cells to develop resistance to known chemotherapeutic treatments dramatically decreases the 5-year survival rate. Chemotherapy with paclitaxel after surgery increases median survival only by 2 to 3 years in stage IV disease highlights the need for more effective drugs. The human immunodeficiency virus (HIV) infection is characterized by increased risk of several solid tumors due to its inherent nature of weakening of immune system. Recent observations point to a lower incidence of some cancers in patients treated with protease inhibitor (PI) cocktail treatment known as HAART (Highly Active Anti-Retroviral Therapy).

Results: Here we show that ritonavir, a HIV protease inhibitor effectively induced cell cycle arrest and apoptosis in ovarian cell lines MDH-2774 and SKOV-3 in a dose dependent manner. Over a 3 day period with 20 muM ritonavir resulted in the cell death of over 60% for MDAH-2774 compared with 55% in case of SKOV-3 cell line. Ritonavir caused G1 cell cycle arrest of the ovarian cancer cells, mediated by down modulating levels of RB phosphorylation and depleting the G1 cyclins, cyclin-dependent kinase and increasing their inhibitors as determined by gene profile analysis. Interestingly, the treatment of ritonavir decreased the amount of phosphorylated AKT in a dose-dependent manner. Furthermore, inhibition of AKT by specific siRNA synergistically increased the efficacy of the ritonavir-induced apoptosis. These results indicate that the addition of the AKT inhibitor may increase the therapeutic efficacy of ritonavir.

Conclusion: Our results demonstrate a potential use of ritonavir for ovarian cancer with additive effects in conjunction with conventional chemotherapeutic regimens. Since ritonavir is clinically approved for human use for HIV, drug repositioning for ovarian cancer could accelerate the process of traditional drug development. This would reduce risks, limit the costs and decrease the time needed to bring the drug from bench to bedside.

Show MeSH
Related in: MedlinePlus