M2muscarinic receptors inhibit cell proliferation and migration in urothelial bladder cancer cells

Abstract

The role of muscarinic receptors in several diseases including cancer has recently emerged. To evaluate the hypothesis that muscarinic acetylcholine receptors may play a role in bladder cancer as well as in other tumor types, we investigated their expression in bladder tumor specimens. All examined samples expressed the M1, M2 and M3 receptor subtypes. We also found that the level of M2 transcripts, but not those of M1 or M3, significantly increased with the tumor histologic grade. In view of these results, we proceeded to investigate whether the M2 agonist Arecaidine had any effect on in vitro cell growth and migration of T24 cells, a bladder tumor cell line expressing the muscarinic receptors, including the M2 subtype. We observed that Arecaidine significantly reduced T24 and 5637 cell proliferation and migration in a concentration dependent manner. The silencing of M2 receptor by siRNA in T24 and 5637 cell lines showed the inability of Arecaidine (100 mM) to inhibit cell proliferation after 48 hours, whereas the use of M1 and M3 antagonists in T24 appeared not to counteract the Arecaidine effect, suggesting that the inhibition of cell proliferation was directly dependent on M2 receptor activation. These data suggest that M2 muscarinic receptors may play a relevant role in bladder cancer and represent a new attractive therapeutic target.

Extra-virgin olive oil phenols block cell cycle progression and modulate chemotherapeutic toxicity in bladder cancer cells

“…First, we evaluated the cell toxicity exerted by EVOOE on two different BCa cell lines, T24 and 5637, which are characterized by two different grades and are widely used as in vitro models (31–33) as they cover the more frequent subtypes of BCa. 5637 cells well represent the E2F3/RB1 pathway due to amplification of 6p22.3, concomitant with loss of one copy of RB1 and mutation of the other copy.…”

The activation of M2 muscarinic receptor inhibits cell growth and survival in human glioblastoma cancer stem cells

“…The presence of muscarinic receptors was also investigated in these Previous studies have already demonstrated the ability of arecaidine 305 to bind to M2 receptor, using pharmacological binding experiments and 306 M2 siRNA transfection [11][12][13][14][15]. By the same methodological approaches 307 we have now demonstrated that arecaidine is able to specifically bind 308 M2 receptors also in GSCs (Figs.…”

“…Moreover, the contribution of muscarinic receptors in tumor 247 progression has been demonstrated[20] and the use of antagonists for 248 different muscarinic receptor subtypes is taking much attention for 249 cancer therapy[21]. Recently we have demonstrated the ability of 250 M2 receptor to influence tumor cell growth and survival both in GBM 251[10,11] and in urothelial bladder cancer cells[15]. ].…”

“…of endogenous M2 receptors was silenced by siRNA 161 as previously reported[11][12][13][14][15]. GB7 cells plated in 6-wells plate at the162 density of 4 × 10 4 cells/well and transfected for 72 h with 40 nM or 163 60 nM M2-siRNA pool (Riboxx Life Sciences, Radebeul, Germany) 164 using the transfection reagent HappyFect (Tecrea, London, UK) accord-165 ing to the manufacturer's instructions.…”

The metronomic combination of paclitaxel with cholinergic agonists inhibits triple negative breast tumor progression. Participation of M2receptor subtype

“…The long-term activation of these receptors with the agonist carbachol stimulates cytotoxicity either in human or in murine breast tumor cells [13,14]. In the last years, several reports demonstrated that the activation of M 2 receptor subtype by a selective agonist was able to arrest cell proliferation in different tumor cell lines [15-17]. Moreover, M 2 receptor activation reduced cell survival, inducing oxidative stress and severe apoptosis in malignant cells derived from human glioblastoma [17].…”