Breast cancer: Muscarinic receptors as new targets for tumor therapy

Table 1 Summary of the expression of muscarinic acetylcholine receptor subtypes (M) in different human cancers

Receptor subtypes	Malignant tissue
M1	Skin[142]	Breast[128]
	Brain[131]	Liver[140]
	Prostate[136]	Esophagus[135]
	Cervix uteri[139]	Pancreas[147]
M2	Lung[134]	Esophagus[135]
	Brain[143]	Bladder[125]
	Breast [128]	Leukemia[145]
M3	Lung [124]	Breast[148]
	Colon[133]	Esophagus[135]
	Skin[142]	Liver[139]
	Prostate[138]	Stomach[132]
	Cervix uteri[139]	Leukemia[145]
	Head and neck[146]
M4	Brain[131]	Breast[128]
	Prostate[137]	Esophagus[135]
	Cervix uteri[139]	Oral cavity[141]
M5	Skin[130]	Breast[128]
	Cervix uteri[139]	Esophagus[135]

Table 2 Effect of metronomic chemotherapy targeting muscarinic acetylcholine receptors on breast tumors

Murine breast malignant cells	Murine breast not malignant cells
Paclitaxel (10-11 mol/L) + Carbachol (10-9 mol/L)[126]
LM2: 68.2 ± 5.1b	NMuMG: 6.8 ± 6.6
LM3: 64.6 ± 6.5b
Human breast malignant cells	Human breast not malignant cells
Paclitaxel (10-9 mol/L) + Carbachol (10-11 mol/L)[127]
MCF-7: 45.6 ± 5.8a	MCF-10A: 1.9 ± 0.3
Paclitaxel (10-9 mol/L) + Carbachol (10-10 mol/L)[128]
MDA-MB468: 33.4 ± 2.5c	MCF-10A: 2.9 ± 3.1
Paclitaxel (10-9 mol/L) + Arecaidine propargyl ester (10-7 mol/L)[128]
MDA-MB468: 26.9 ± 3.6c	MCF-10A: 3.3 ± 6.2
Paclitaxel (10-8 mol/L) + Carbachol (10-11 mol/L)[128]
MDA-MB231: 36.8 ± 6.2c	MCF-10A: 3.1 ± 6.2
Doxorubicin (10-8 mol/L) + Carbachol (10-11 mol/L)[128]
MDA-MB231: 35.3 ± 0.8c	MCF-10A: 6.1 ± 3.1
Paclitaxel (10-8 mol/L) + Arecaidine propargyl ester (10-5 mol/L)[128]
MDA-MB231: 35.8 ± 3.1c	MCF-10A: 8.2 ± 6.5
Doxorubicin (10-8 mol/L) + Arecaidine propargyl ester (10-5 mol/L)[128]
MDA-MB231: 33.3 ± 2.1c	MCF-10A: 7.8 ± 6.8
Paclitaxel (10-6 mol/L)[128]
MDA-MB231: 38.0 ± 6.1c	MCF-10A: 33.3 ± 1.5c
Doxorubicin (10-6 mol/L)[128]
MDA-MB231: 41.1 ± 2.3c	MCF-10A: 45.7 ± 1.8c

^aP < 0.01.

^bP < 0.001.

^cP < 0.0001 vs control (untreated cells).