The Combination of the M2 Muscarinic Receptor Agonist and Chemotherapy Affects Drug Resistance in Neuroblastoma Cells

Abstract

One of the major limits of chemotherapy is depending on the ability of the cancer cells to elude and adapt to different drugs. Recently, we demonstrated how the activation of the M2 muscarinic receptor could impair neuroblastoma cell proliferation. In the present paper, we investigate the possible effects mediated by the preferential M2 receptor agonist arecaidine propargyl ester (APE) on drug resistance in two neuroblastoma cell lines, SK-N-BE and SK-N-BE(2C), a sub-clone presenting drug resistance. In both cell lines, we compare the expression of the M2 receptor and the effects mediated by the M2 agonist APE on cell cycle, demonstrating a decreased percentage of cells in S phase and an accumulation of SK-N-BE cells in G1 phase, while the APE treatment of SK-N-BE(2C) cells induced a block in G2/M phase. The withdrawal of the M2 agonist from the medium shows that only the SK-N-BE(2C) cells are able to rescue cell proliferation. Further, we demonstrate that the co-treatment of low doses of APE with doxorubicin or cisplatin significantly counteracts cell proliferation when compared with the single treatment. Analysis of the expression of ATP-binding cassette (ABC) efflux pumps demonstrates the ability of the M2 agonist to downregulate their expression and that this negative modulation may be dependent on N-MYC decreased expression induced by the M2 agonist. Our data demonstrate that the combined effect of low doses of conventional drugs and the M2 agonist may represent a new promising therapeutic approach in neuroblastoma treatment, in light of its significant impact on drug resistance and the possible reduction in the side effects caused by high doses of chemotherapy drugs.

M2 Muscarinic Receptor Activation Impairs Mitotic Progression and Bipolar Mitotic Spindle Formation in Human Glioblastoma Cell Lines

“…These results, together with the data obtained in other tumor types (i.e., neuroblastoma, breast cancer, and urothelial cancer) [13,15,40,41], highlight the M2 muscarinic receptor as a new strategic therapeutic target in cancer therapy. Therefore, a special effort to identify new selective ligands able to bind this receptor with more efficacy and to reduce the possible side effects appears clinically relevant and may open new therapeutic perspectives for glioblastoma treatment, as well as for the treatment of other tumors.…”

“…mAChRs are expressed in several primary and metastatic tumors, such as breast [ 7 ], ovarian [ 8 ], and lung cancers [ 9 ] and in astrocytoma and glioblastoma cells [ 10 , 11 , 12 ]. In particular, M2 mAChRs appear to be involved in tumor behavior, negatively modulating the proliferation and the migration of cancer cells [ 13 , 14 , 15 ].…”

The Combined Treatment with Chemotherapeutic Agents and the Dualsteric Muscarinic Agonist Iper-8-Naphthalimide Affects Drug Resistance in Glioblastoma Stem Cells

“…At the same dose as APE, N-8-Iper not only reduced cell growth but also caused cell death [43]. Our more recent studies have shown that M2 receptor activation by APE caused a downregulation of the ATP-binding cassette (ABC) efflux pumps expression in neuroblastoma and in breast cancer [44,45]. Furthermore, co-treatment with chemotherapy drugs and M2 mAChR agonists significantly counteracts cell proliferation when compared with the single treatment [44].…”

“…Our more recent studies have shown that M2 receptor activation by APE caused a downregulation of the ATP-binding cassette (ABC) efflux pumps expression in neuroblastoma and in breast cancer [44,45]. Furthermore, co-treatment with chemotherapy drugs and M2 mAChR agonists significantly counteracts cell proliferation when compared with the single treatment [44]. Based on these results, in the present work we firstly investigated the ability of N-8-Iper to modulate cell proliferation in another GSC line (G166 cells) in order to extend the previous observation obtained in a single cell line (GB7).…”

Breast cancer: Muscarinic receptors as new targets for tumor therapy

“…However, when analyzing the function of mAChRs in tumor tissues, other authors confirmed opposite results, particularly considering the expression and function of the M2 receptor subtype. Lucianò et al [ 143 ], for example, established that two cell lines derived from a neuroblastoma with bad prognosis, SK-N-BE and SK-N-BE(2C), express the M2 receptor and that its activation inhibits the cell cycle. In human bladder tumors, Pacini et al [ 125 ] reported the expression of M2 receptor protein and found that its stimulation reduced cell proliferation and migration.…”