Identifying bias in CCR1 antagonists using radiolabelled binding, receptor internalization, β-arrestin translocation and chemotaxis assays

Br J Pharmacol. 2014 Nov;171(22):5127-38. doi: 10.1111/bph.12835.


Background and purpose: Investigators have suggested that the chemokine receptor CCR1 plays a role in multiple myeloma. Studies using antisense and neutralizing antibodies to CCR1 showed that down-regulation of the receptor altered disease progression in a mouse model. More recently, experiments utilizing scid mice injected with human myeloma cells demonstrated that the CCR1 antagonist BX471 reduced osteolytic lesions, while the CCR1 antagonist MLN-3897 prevented myeloma cell adhesion to osteoclasts. However, information is limited regarding the pharmacology of CCR1 antagonists in myeloma cells.

Experimental approach: We compared several well-studied CCR1 antagonists including AZD4818, BX471, CCX354, CP-481715, MLN-3897 and PS899877 for their ability to inhibit binding of [(125)I]-CCL3 in vitro using membranes prepared from RPMI 8226 cells, a human multiple myeloma cell line that endogenously expresses CCR1. In addition, antagonists were assessed for their ability to modulate CCL3-mediated internalization of CCR1 and CCL3-mediated cell migration using RPMI 8226 cells. As many GPCRs signal through β-arrestin-dependent pathways that are separate and distinct from those driven by G-proteins, we also evaluated the compounds for their ability to alter β-arrestin translocation.

Key results: There were clear differences between the CCR1 antagonists in their ability to inhibit CCL3 binding to myeloma cells, as well as in their ability to inhibit G-protein-dependent and -independent functional responses.

Conclusions and implications: Our studies demonstrate that tissue phenotype seems to be relevant with regards to CCR1. Moreover, it appears that for CCR1 antagonists, inhibition of β-arrestin translocation is not necessarily linked to chemotaxis or receptor internalization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrestins / metabolism
  • CHO Cells
  • Cell Line, Tumor
  • Chemokine CCL3 / metabolism
  • Chemotaxis
  • Cricetulus
  • HEK293 Cells
  • Humans
  • Multiple Myeloma
  • Phenylurea Compounds / pharmacology
  • Piperidines / pharmacology
  • Quinoxalines / pharmacology
  • Radioligand Assay
  • Receptors, CCR1 / antagonists & inhibitors*
  • Receptors, CCR1 / metabolism*
  • Spiro Compounds / pharmacology
  • beta-Arrestins


  • AZD-4818
  • Arrestins
  • CCR1 protein, human
  • Chemokine CCL3
  • Phenylurea Compounds
  • Piperidines
  • Quinoxalines
  • Receptors, CCR1
  • Spiro Compounds
  • beta-Arrestins
  • quinoxaline-2-carboxylic acid (4-carbamoyl-1-(3-fluorobenzyl)-2,7-dihydroxy-7-methyloctyl)amide
  • BX 471