Effects of pharmacological calcimimetics on colorectal cancer cells over-expressing the human calcium-sensing receptor

• Published in: Biochimica et biophysica acta. Molecular cell research Vol. 1867; no. 12; p. 118836
• Main Authors: Iamartino, Luca, Elajnaf, Taha, Gall, Katharina, David, Jacquelina, Manhardt, Teresa, Heffeter, Petra, Grusch, Michael, Derdak, Sophia, Baumgartner-Parzer, Sabina, Schepelmann, Martin, Kallay, Enikö
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2020
• Subjects: Animals; Caco-2 Cells; Calcimimetic; Calcimimetic Agents - pharmacology; Calcium-sensing receptor; Cell Differentiation - drug effects; Cell Proliferation - drug effects; Colorectal cancer; Colorectal Neoplasms - drug therapy; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; Gene Expression Regulation, Neoplastic - drug effects; Heterografts; Humans; Inflammation; Interleukin-23 Subunit p19 - genetics; Interleukin-8 - genetics; Intestine; Mice; Phenethylamines - pharmacology; Propylamines - pharmacology; Receptors, Calcium-Sensing - genetics; Receptors, G-Protein-Coupled - genetics; FDA; CSF1; PLC; Colorectal cancer; USH1C; IBD; MTT; DLL1; DLL4; PECAM1 or CD31; NF-κB; Calcimimetic; MUC2; FDR; Intestine; CCL-20; COX2; Gq/11; Calcium-sensing receptor; ATOH1; AOM; CDX2; DSS; CI; GO; MYO7B; PAX4; DAPI; Inflammation; IP1; IL-34; IL-8; IL-1α; IP3; IL-6; IL-23α; GPCR; ANKS4B; INSM1; PDL-1; BrdU; NEUROG3
• ISSN: 0167-4889; 1879-2596
• DOI: 10.1016/j.bbamcr.2020.118836

The calcium-sensing receptor (CaSR) is a ubiquitously expressed multifunctional G protein-coupled receptor. Several studies reported that the CaSR plays an anti-inflammatory and anti-tumorigenic role in the intestine, and that it is down-regulated during colorectal carcinogenesis. We hypothesized that positive allosteric CaSR modulators (type II calcimimetics) selectively targeting the intestinal cells could be used for the treatment of intestinal pathologies. Therefore, the aim of this study was to determine the effect of pharmacological stimulation of CaSR on gene expression in vitro and on tumor growth in vivo. We stably transduced two colon cancer cell lines (HT29 and Caco2) with lentiviral vectors containing either the CaSR fused to GFP or GFP only. Using RNA sequencing, RT-qPCR experiments and ELISA, we determined that CaSR over-expression itself had generally little effect on gene expression in these cells. However, treatment with 1 μM of the calcimimetic NPS R-568 increased the expression of pro-inflammatory factors such as IL-23α and IL-8 and reduced the transcription of various differentiation markers in the cells over-expressing the CaSR. In vivo, neither the presence of the CaSR nor p.o. treatment of the animals with the calcimimetic cinacalcet affected tumor growth, tumor cell proliferation or tumor vascularization of murine HT29 xenografts. In summary, CaSR stimulation in CaSR over-expressing cells enhanced the expression of inflammatory markers in vitro, but was not able to repress colorectal cancer tumorigenicity in vivo. These findings suggest potential pro-inflammatory effects of the CaSR and type II calcimimetics in the intestine. [Display omitted] •CaSR stimulation enhances the expression/secretion of pro-inflammatory markers.•CaSR stimulation inhibits the expression of intestinal differentiation markers.•CaSR stimulation fails to inhibit growth of subcutaneous xenografts in SCID mice.