Methadone does not potentiate the effect of doxorubicin in canine tumour cell lines

Cueni, Claudia; Nytko, Katarzyna J.; Thumser-Henner, Pauline; Weyland, Mathias S.; Bley, Carla Rohrer

doi:10.1002/vms3.266

Cited by 5 publications

(6 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have previously shown that P-gp is not expressed in U87, U251 and U373 cell lines [18] which might explain why these cells could not be sensitized to doxorubicin by MET, while inhibition of doxorubicin e ux has previously been reported for the A172 cell line [10]. Our ndings are in line with a study which also reported no sensitizing effect of MET on various doxorubicintreated canine tumor cells [12].…”

Section: Discussionsupporting

confidence: 89%

See 1 more Smart Citation

Chemotherapy Sensitizing Effects of Methadone in Glioblastoma Cells Are Drug- and Cell Line-dependent

Haas

Ciftcioglu

Jermar

et al. 2020

Preprint

View full text Add to dashboard Cite

Background D,L-methadone (MET), an analgesic drug used for pain treatment and opiate addiction has achieved attention from oncologist and social media as possible chemosensitizing agent in glioblastoma multiforme (GBM) treatment. MET has been reported to enhance doxorubicin-induced cytotoxicity in GBM cells via activation of the µ-opioid receptor (MOR) and subsequent apoptosis induction. Here, we further aimed at quantifying MET effects in comparison to other opioids alone and in combination with doxorubicin and clinically more relevant temozolomide (TMZ) in a set of GBM cell lines and primary GBM cells. Methods MOR expression in GBM cells was investigated by immunofluorescence and immunoblotting. Resistance to drugs alone or in combination was assessed by MTT assays. Concentration effect curves were fitted to data points by nonlinear regression analysis and IC50 values were calculated. Apoptotic rates were determined by Annexin V staining. Results We found that MET alone was cytotoxic to GBM cells at high micromolar concentrations in MTT assays by induction of apoptosis and necrosis while morphine and oxycodone were hardly cytotoxic. Naloxone was not able to block MET-induced cytotoxicity, indicating that cell death inducing effects of MET are not MOR dependent. We recorded doxorubicin and TMZ concentration response curves by MTT assays in combination with fixed MET concentrations. MET only enhanced doxorubicin cytotoxicity in one cell line and in part in primary cells at certain MET concentrations. MET was not effective in sensitizing cells towards TMZ. Contrarily, in two cell lines MET even decreased sensitivity towards TMZ. Conclusions MET can be considered cytotoxic to GBM cells only at clinically not relevant concentrations by induction of apoptosis and necrosis. Sensitizing effects are only observed in combination with doxorubicin but not with TMZ and are highly dependent on cell line and applied drug concentrations.

show abstract

Section: Discussionsupporting

confidence: 89%

“…In a tumor model of nude mice implanted with U87 GBM cells, MET treatment reduced tumor growth and volume [9]. On the other hand, more recent data indicate no sensitizing effect of MET on various doxorubicin-treated canine tumor cells [12].…”

Section: Introductionmentioning

confidence: 99%

Chemotherapy Sensitizing Effects of Methadone in Glioblastoma Cells Are Drug- and Cell Line-dependent

Haas

Ciftcioglu

Jermar

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Doxorubicin is frequently used in veterinary medicine; thus, the question arose whether MTD is useful also for increasing the effectiveness of therapy of animals. In a recent study with µ-receptor expressing canine cell lines, authors did not observe a potentiation of doxorubicin-induced growth inhibition by MTD and, overall, were unable to confirm the data summarized above [ 18 ].…”

Section: Discussionmentioning

confidence: 99%

Cytotoxic and Senolytic Effects of Methadone in Combination with Temozolomide in Glioblastoma Cells

Kaina

Beltzig

Piée-Staffa

et al. 2020

IJMS

View full text Add to dashboard Cite

Methadone is an analgesic drug used for pain treatment and heroin substitution. Recently, methadone has been proposed to be useful also for cancer therapy, including glioblastoma multiforme (GBM), the most severe form of brain cancer, because experiments on cultured glioma cells treated with doxorubicin showed promising results. Doxorubicin, however, is not used first-line in GBM therapy. Therefore, we analyzed the cytotoxic effect of methadone alone and in combination with temozolomide, a DNA-alkylating drug that is first-line used in GBM treatment, utilizing GBM-derived cell lines and a human fibroblast cell line. We show that methadone is cytotoxic on its own, inducing apoptosis and necrosis, which was observed at a concentration above 20 µg/mL. Methadone was similar toxic in isogenic MGMT expressing and non-expressing cells, and in LN229 glioblastoma and VH10T human fibroblasts. The apoptosis-inducing activity of methadone is not bound on the opioid receptor (OR), since naloxone, a competitive inhibitor of OR, did not attenuate methadone-induced apoptosis/necrosis. Administrating methadone and temozolomide together, temozolomide had no impact on methadone-induced apoptosis (which occurred 3 days after treatment), while temozolomide-induced apoptosis (which occurred 5 days after treatment) was unaffected at low (non-toxic) methadone concentration (5 µg/mL), and at high (toxic) methadone concentration (20 µg/mL) the cytotoxic effects of methadone and temozolomide were additive. Methadone is not genotoxic, as revealed by comet and γH2AX assay, and did not ameliorate the genotoxic effect of temozolomide. Further, methadone did not induce cellular senescence and had no effect on temozolomide-induced senescence. Although methadone was toxic on senescent cells, it cannot be considered a senolytic drug since cytotoxicity was not specific for senescent cells. Finally, we show that methadone had no impact on the MGMT promoter methylation. Overall, the data show that methadone on glioblastoma cells in vitro is cytotoxic and induces apoptosis/necrosis at doses that are above the level that can be achieved in vivo. It is not genotoxic, and does not ameliorate the cell killing or the senescence-inducing effect of temozolomide (no synergistic effect), indicating it has no impact on temozolomide-induced signaling pathways. The data do not support the notion that concomitant methadone treatment supports temozolomide-based chemotherapy.

show abstract

“…The proposed mechanism of action rests on activation of MOR, inhibition of P-gp by MET leading to increased intracellular doxorubicin levels, and subsequent induction of apoptosis (Friesen et al 2014). In another study, the data were not reproduced in doxorubicin and MET-treated canine tumor cells (Cueni et al 2020), indicating a need for further in vitro studies. MET has also been implicated in enhancing cytotoxic effects of other chemotherapeutics in cancer cell lines of different origins, such as bladder cancer, squamous cell carcinoma and head and neck cancer, albeit with varying efficacy, greatly depending on cell type, the chemotherapeutic agent and applied concentrations (Landgraf et al 2019;Michalska et al 2018;Shi et al 2019).…”

Section: Discussionmentioning

confidence: 99%

“…In addition, it was shown that MET increases intracellular doxorubicin levels probably by inhibiting P-glycoproteins (P-gp) in GBM cells (Friesen et al 2014). On the other hand, data published by others indicate no sensitizing effect of MET on various doxorubicin-treated canine tumor cells (Cueni et al 2020).…”

Section: Introductionmentioning

confidence: 90%

Methadone-mediated sensitization of glioblastoma cells is drug and cell line dependent

Haas

Ciftcioglu

Jermar

et al. 2020

J Cancer Res Clin Oncol

View full text Add to dashboard Cite

Purpose d,l-methadone (MET), an analgesic drug used for pain treatment and opiate addiction, has achieved attention from oncologists and social media as possible chemoensitizing agent in cancer therapy, notably brain cancer (glioblastoma multiforme, GBM). MET has been reported to enhance doxorubicin-induced cytotoxicity in GBM cells via activation of the µ-opioid receptor (MOR). Here, we extended this work and quantified the toxic effect of MET in comparison to other opioids alone and in combination with doxorubicin and the clinically more relevant alkylating drug temozolomide (TMZ), using a set of GBM cell lines and primary GBM cells. Methods MOR expression in GBM cells was investigated by immunofluorescence and immunoblotting. Resistance to drugs alone and in combination with anticancer drugs was assessed by MTT assays. Concentration effect curves were fitted by nonlinear regression analysis and IC50 values were calculated. Apoptosis and necrosis rates were determined by annexin V/propidium iodide (PI)-flow cytometry. Results MET alone was cytotoxic in all GBM cell lines and primary GBM cells at high micromolar concentrations (IC50 ~ 60–130 µM), observed both in the metabolic MTT assay and by quantifying apoptosis and necrosis, while morphine and oxycodone were not cytotoxic in this concentration range. Naloxone was not able to block MET-induced cytotoxicity, indicating that cell death-inducing effects of MET are not MOR-dependent. We recorded doxorubicin and TMZ concentration- response curves in combination with fixed MET concentrations. MET enhanced doxorubicin-induced cytotoxicity in only one cell line, and in primary cells it was observed only in a particular MET concentration range. In all assays, MET was not effective in sensitizing cells to TMZ. In two cell lines, MET even decreased the cell's sensitivity to TMZ. Conclusion MET was found to be cytotoxic in GBM cells in vitro only at high, clinically not relevant concentrations, where it was effective in inducing apoptosis and necrosis. Sensitizing effects were only observed in combination with doxorubicin, but not with TMZ, and are dependent on cell line and the applied drug concentration. Therefore, our findings do not support the use of MET in the treatment of GBM in combination with TMZ, as no sensitizing effect of MET was observed.

show abstract

Methadone does not potentiate the effect of doxorubicin in canine tumour cell lines

Cited by 5 publications

References 29 publications

Chemotherapy Sensitizing Effects of Methadone in Glioblastoma Cells Are Drug- and Cell Line-dependent

Chemotherapy Sensitizing Effects of Methadone in Glioblastoma Cells Are Drug- and Cell Line-dependent

Cytotoxic and Senolytic Effects of Methadone in Combination with Temozolomide in Glioblastoma Cells

Methadone-mediated sensitization of glioblastoma cells is drug and cell line dependent

Contact Info

Product

Resources

About