D,L-Methadone enhances the cytotoxic activity of standard chemotherapeutic agents on pediatric rhabdomyosarcoma

Cristian Urla,Steven W Warmann,Jörg Fuchs,Irene Corteletti,Evi Schmid,Ann-Sophie Raible,Rupert Handgretinger

doi:10.1007/s00432-022-03945-y

Abstract

PurposeIn advanced tumor stages, pediatric rhabdomyosarcoma (RMS) shows an intrinsic resistance to standard chemotherapy, which is associated with a dismal prognosis. Alternative therapeutic approaches and optimization of already existent treatment protocols are urgently needed in these conditions. The µ-opioid receptor (OPRM1) agonist, D,L-methadone is frequently used for analgesia in oncological patients. Recent evidence has shown that D,L-methadone in combination with chemotherapeutic agents may enhance their cytotoxic effect against cancer cells. There are no related data in pediatric rhabdomyosarcoma (RMS).MethodsAntitumor effects of combined D,L-methadone and doxorubicin, carboplatin, and vincristine on RMS cell lines RD and RH30 were analyzed using following outcome data: expression of the OPRM1 receptor (Western blot), cell growth inhibition (MTT assay), cell migration (wound-healing assay), apoptosis induction (caspase-3/7 assay), and reactive oxygen species (ROS) production (flow cytometry).ResultsIn both cell lines, OPRM1 expression was significantly increased after combined treatment of D,L-methadone with all three cytotoxic drugs tested, which resulted in suppression of tumor cell growth and increase of apoptosis rates. These effects were mediated by increased ROS production and up-regulation of caspase-3/7 activity. Doxorubicin combined with D,L-methadone significantly reduced cell migration in both cell lines. Carboplatin or vincristine in combination with D,L-methadone had only an impact on cell migration in RH30 cells.ConclusionsThis new therapeutic approach in RMS provides strong antitumor effects in vitro. The combination of standard chemotherapy and D,L-methadone requires further investigation. Especially advanced tumors with a limited effectiveness of conventional treatment regimens seem a potential target of this approach.

Highlights

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma, accounting for 5% of all cases of pediatric solid tumors (Dasgupta et al 2016)
We analyzed the effects of D,L-methadone in combination with doxorubicin, carboplatin, and vincristine in pediatric RMS cell lines
We observed that the combined treatment significantly suppressed tumor cell growth and increased reactive oxygen species (ROS) production compared to the treatment with cytostatic drugs alone

Summary

Introduction

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma, accounting for 5% of all cases of pediatric solid tumors (Dasgupta et al 2016). The prognosis of children with RMS has dramatically improved since introduction of multimodal treatment regimens. A major role in developing new therapeutic strategies has been carried out by cooperative clinical trial groups in Europe and North America The patients are treated according to the risk group they were assigned. Chemotherapy remained an essential component of the multimodal treatment. Within CWS trials, standard-risk patients receive ifosfamide, vincristine and actinomycin-D. Very high-risk patients are treated with doxorubicin. Patients with relapse receive a second-line chemotherapy including topotecan, etoposide, carboplatin, and cyclophosphamide Klingebiel et al 1998; Längler et al 2002)

Objectives

Methods

Results

Conclusion