New Therapeutic Strategy for Overcoming Multidrug Resistance in Cancer Cells with Pyrazolo[3,4-d]pyrimidine Tyrosine Kinase Inhibitors.

Ana Podolski-Renić,Tijana Stanković,Jelena Dinić,Lorenzo Botta,Milica Pešić,Silvia Schenone,Ivanka Tsakovska,Ilza Pajeva,Tiziano Tuccinardi

doi:10.3390/cancers13215308

Abstract

Simple SummaryP-glycoprotein (P-gp) is an ATP-binding cassette transporter whose overexpression in cancer cells is one of the main causes of multidrug resistance (MDR). Tyrosine kinase inhibitors (TKIs) have been reported to interact with ABC transporters and in some cases, increase the susceptibility of cancer cells to chemotherapy. We investigated the potential of novel TKI pyrazolo[3,4-d] pyrimidines and their prodrugs to inhibit P-gp in two MDR cancer cell lines with P-gp overexpression. The tested compounds were able to suppress P-gp by inhibiting its ATPase activity. Interestingly, prodrugs displayed a stronger potential to modulate P-gp and showed higher interaction energies in the docking simulations compared to their parent drugs. Furthermore, prodrugs showed significant potential to inhibit P-gp activity even in prolonged treatment and therefore to enhance the efficacy of doxorubicin and paclitaxel in MDR cancer cells. All of these characteristics imply that the new TKIs could be considered a valuable strategy for combating resistant cancers, especially in combination with other chemotherapeutics.Tyrosine kinase inhibitors (TKIs) often interact with the multidrug resistant (MDR) phenotype of cancer cells. In some cases, TKIs increase the susceptibility of MDR cancer cells to chemotherapy. As the overexpression of membrane transporter P-glycoprotein (P-gp) is the most common alteration in MDR cancer cells, we investigated the effects of TKI pyrazolo[3,4-d]pyrimidines on P-gp inhibition in two cellular models comprising sensitive and corresponding MDR cancer cells (human non-small cell lung carcinoma and colorectal adenocarcinoma). Tested TKIs showed collateral sensitivity by inducing stronger inhibition of MDR cancer cell line viability. Moreover, TKIs directly interacted with P-gp and inhibited its ATPase activity. Their potential P-gp binding site was proposed by molecular docking simulations. TKIs reversed resistance to doxorubicin and paclitaxel in a concentration-dependent manner. The expression studies excluded the indirect effect of TKIs on P-gp through regulation of its expression. A kinetics study showed that TKIs decreased P-gp activity and this effect was sustained for seven days in both MDR models. Therefore, pyrazolo[3,4-d]pyrimidines with potential for reversing P-gp-mediated MDR even in prolonged treatments can be considered a new therapeutic strategy for overcoming cancer MDR.

Highlights

One of the major limitations for successful cancer treatment is the development of multidrug resistance (MDR)
As the overexpression of membrane transporter P-glycoprotein (P-gp) is the most common alteration in multidrug resistant (MDR) cancer cells, we investigated the effects of Tyrosine kinase inhibitors (TKIs) pyrazolo[3,4-d]pyrimidines on P-gp inhibition in two cellular models comprising sensitive and corresponding MDR cancer cells
Collateral sensitivity to Src family tyrosine kinases (SFK) inhibitors was observed in colorectal carcinoma cells owing to the fact that MDR DLD1-TxR cells were more sensitive to all analyzed SFK inhibitors compared to DLD1 cells

Summary

Introduction

One of the major limitations for successful cancer treatment is the development of multidrug resistance (MDR). The concept of MDR indicates that cancer cells become resistant to applied drugs and to a broad array of compounds with unrelated structures and modes of action [1]. MDR is commonly associated with the overexpression of ATP-binding cassette (ABC) transporters in the cancer cell membrane. ABC transporters utilize the energy from ATP hydrolysis to extrude drugs against their concentration gradients [2]. Members of the ABC transporter family that have been clearly correlated with MDR are P-glycoprotein (P-gp/ABCB1), multidrug resistance protein 1 (MRP1/ABCC1), and breast cancer resistance protein (BCRP/BCG2) [1]. Functional P-gp contains two homologous transmembrane domains (TMDs) and two homologous intracellular nucleotide-binding domains (NBDs) or ATP-binding cassettes [5]. Each NBD contains ATPase sites, which directly mediate the binding and hydrolysis of ATP [5]. P-gp activity could be suppressed when ATP hydrolysis is highly stimulated due to overloading by its substrate or when ATP hydrolysis is suppressed [7]

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