PPARγ activation by pioglitazone enhances the anti-proliferative effects of doxorubicin on pro-monocytic THP-1 leukemia cells via inducing apoptosis and G2/M cell cycle arrest

Abstract

Purpose

Doxorubicin (DOX) is a common chemotherapeutic agent, with toxic side effects, and chemoresistance. Combination chemotherapy is a successful approach to overcome these limitations. Here, we investigated the effects of pioglitazone (PGZ), a PPARγ agonist, and/or DOX on the viability, cell cycle, apoptosis on THP-1 cells and normal human monocytes (NHMs).

Methods

MTT assay was used to evaluate the cytotoxicity of DOX and/or PGZ. Cell cycle progression and apoptosis induction were examined by PI or Annexin V-PI double staining, and analyzed by flow cytometry. Quantitative RT-PCR was used to evaluate the changes in the mRNA expression of cell cycle progression or apoptosis-associated genes including P27, P21, CDK2, P53, BCL2 and FasR.

Results

DOX, PGZ and DOX + PGZ exerted their cytotoxic effects in a dose- and time-dependent manner with low toxicity on NHMs. The cell growth inhibitory effects of DOX were in association with G2/M arrest, while PGZ executed S phase arrest. PGZ treatment enhanced G2/M among DOX-treated combinations with moderate elevation in the S phase. DOX, PGZ and combined treatments induced apoptosis (mostly late phase) in a dose-dependent manner. All treatments resulted in the significant overexpression of p21, p27, p53 and FasR genes and downregulation of CDK2. DOX + PGZ combined treatments exhibited the most significant changes in mRNA expression.

Conclusion

We demonstrated that the antiproliferative, cell cycle regulation and apoptosis-inducing capacity of DOX was enhanced by PGZ in THP-1 leukemia cells in a dose-dependent manner. Therefore, the combination of DOX + PGZ could be used as a novel combination to target AML.

Keywords:

• Acute myeloid leukemia (AML)
• apoptosis
• cell cycle
• combination chemotherapy
• doxorubicin
• peroxisome proliferator-activated receptor gamma (PPAR-γ)
• pioglitazone

Acknowledgments

We wish to thank Daroo Darman Pars company for providing us with Pioglitazone.

Author contributions

Study conception or design: H G, and S M; Data Processing, Collection, Perform Experiment: H G, A J, M A G, M K, M R, and S M; Data analyzing and draft manuscript preparation: H G, M R and S M; Critical revision of the paper: S M; Supervision of the research: SM; Final approval of the version to be published: H G, A J, M A G, K M, M K, M R, S M.

Ethical approval

The current work was conducted according to the guidelines provided by the national committee of ethics at the Iranian ministry of health and approved by the committee of ethics at Abadan School of Medical Sciences (Code of ethics: IR.ABADANUMS.REC.1395.186).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by a grant from Abadan School of Medical Sciences, Abadan, Iran [Grant Code: 95011101132].