Insights into the therapeutic outcomes of trimetazidine/doxorubicin combination in Ehrlich solid-phase carcinoma mouse tumor model

Abstract

One of the key features of cancer is metabolic reprogramming that can be exploited to sensitize cancer cells to chemotherapy. Trimetazidine (TMZ) is a metabolic anti-ischemic drug that blocks the activity of long-chain 3-ketoacyl CoA thiolase leading to the inhibition of fatty acid oxidation. AimsThe objective of the current investigation was to evaluate the idea that TMZ could synergize the antitumor activity of doxorubicin (DOX). Main methodsThe hypothesis was examined in vitro using the human breast cancer cell lines MCF-7 and MDA-MB231. In addition, the in vivo experiments were conducted using the Ehrlich solid phase carcinoma model. Key findingsIn vitro cytotoxicity experiments demonstrated that TMZ improved the potency of DOX in MCF-7 cell lines in a synergistic manner. In vivo testing confirmed that DOX/TMZ combination exhibits synergistic effect at both DOX/TMZ 1:10 and 1:5 ratios, where DOX was administered at one tenth and one fifth of its original dose, respectively. The co-treatment (1:5 ratio) significantly reduced tumor Nicotinamide adenine dinucleotide (NAD)+/NADH ratio (6.1-fold) and Adenosine triphosphate (ATP) levels (61 %) with concurrent activation of AMP-activated protein kinase (AMPK) (2.2-fold) and peroxisome proliferator-activated receptor-gamma coactivator (PGC)1-α (5.5-fold) protein expression versus control. The same treatment decreased the nuclear levels of NF-κB (p65) (57.5 %) and induced tumor apoptosis as evidenced by elevated Bax/Bcl-2 ratio (6.8-fold) along with active caspase-3 levels (6.6-fold) against control. SignificanceThe current investigation constitutes a proof-of-concept study that provided preclinical evidence for the anticancer activity of DOX/TMZ combination and warrants further investigation for repurposing TMZ in DOX protocols.