Fig. 9: Syndecan-1 loss impairs integrin β7 activity.

a Number of colonies generated from shCTRL or shItgβ7 knockdown of bcCML cells after the primary (left panel) and secondary plating (right panel). **P = 0.001, ***P = 0.0006 (n = 3 technical replicates, representative of 3 biological replicates). b SDF-1 induced migration of shCTRL or shItgβ7 bcCML cells across HUVEC monolayers seeded on fibronectin-coated transwell filters. *P = 0.01 (n = 4 technical replicates, representative of two biological replicates). c SDF-1 induced migration of WT or Sdc1^−/− bcCML cells across MAdCAM coated transwell filters. ***P = 0.0002 (n = 4 technical replicates, representative of two biological replicates). d Soluble ligand binding assay with WT and Sdc1^−/− bcCML and the Itgβ7 ligand, MAdCAM-1, either resting or stimulated with 200 nM phorbol myristate acetate (PMA). Data are normalized to non-physiological stimulation with 1 mM Mn²⁺ (n = 2 technical replicates, representative of two biological replicates). e Soluble ligand binding assay with WT and Sdc1^−/− bcCML and the Itgβ1 ligand, VCAM-1, either resting or stimulated with 200 nM PMA. Data are normalized to non-physiological stimulation with 1 mM Mn²⁺. (n = 2 technical replicates, representative of two biological replicates). f Rescue of Sdc1^−/− primary and secondary colony formation by ectopic expression of either empty GFP control, wild-type Sdc1, Itgβ7 or Sdc1 + Itgβ7. (n = 3 technical replicates, representative of three biological replicates). g Rescue of Sdc1^−/− migration on FN coated filters by ectopic expression of either empty GFP control, wild-type Sdc1, or Itgβ7. *P = 0.02, ***P = 0.0009, #P = 0.04, ##P = 0.002. *Significance from WT bcCML +  empty GFP, #significance from Sdc1^−/− + empty GFP (n = 3 technical replicates, representative of three biological replicates). Two-tailed unpaired Student’s t-tests were used to determine statistical significance. Source data are provided as a Source Data File.