Table 2.

Dual function of the calcium-sensing receptor as tumour suppressor and oncogene in various cancers and the affected calcium-sensing receptor-coupled signalling pathways

Cancer type	CaSR	Expression of the CaSR	Detection	Proposed signalling pathway	Ref.
Gastric	Oncogene	Increased	mRNA, protein	TRPV4	[49]
Prostate	Oncogene	Increased	mRNA, protein	PTHrP via trans-activation of the EGFR and ERK1/2 phosphorylation	[50-52]
				AKT phosphorylation
Breast	Oncogene	Increased in breast primary tumours and in bone metastases	mRNA, protein	PTHrP via cAMP	[53-57]
				ERK1/2 and TRPC1
				Inhibition of OPG via epiregulin
Renal carcinoma	Oncogene	Increased in bone metastasising tumours	mRNA, protein	AKT phosphorylation	[58]
Colorectal	Tumour suppressor	Reduced	mRNA, protein	Canonical and non-canonical Wnt/β-catenin pathway and EMT	[3,29,59-62]
Endometrial	Tumour suppressor	Reduced	Protein	Apoptosis	[63]
				Wnt/β-catenin
				VEGFR3
Parathyroid	Tumour suppressor	Reduced	mRNA, protein	Caveolin-1 and Gαq	[64-69]
				Cyclin D1 and RGS5
Neuro-blastoma	Tumour suppressor	Reduced	mRNA, protein	Apoptosis via ERK1/2	[22,70,71]
				Cancer testis antigens (CTAs)
Pancreatic	Unknown	Reduced	mRNA, protein	NCX1/Ca2+/ β-catenin	[19,72]