Fig. 8: MGP contributes to breast cancer cell adhesion.

a MGP expression in LECs after CM treatment with anti-MGP antibody (n = 5–6 HLECs), analyzed using one-way ANOVA linear mixed models (Sidak correction). b MGP expression in LECs exposed to anti-MGP antibody or recombinant MGP (n = 6–10 HLECs), analyzed using two-way ANOVA linear mixed models (Sidak correction). c MGP expression in siRNA-silenced LECs (n = 5 HLECs), analyzed by two-sided Mann–Whitney U-test. d Tube formation quantified by number of nodes, junctions and branches in MGP-silenced vs. control LECs, shown as geometric mean with 95% CI (n = 17 HLECs), analyzed with a two-sided paired t-test. e Scratch assay of MGP-silenced and control LECs over 2 days (mean ± SEM; n = 13 HLECs), analyzed by repeated measures two-way ANOVA (matched full mixed model) with Sidak’s multiple comparisons. f Soluble MGP binding to cancer cells: MGP (His) was added with anti-His antibody (red), while the control (blue) contained only cancer cells with antibody. Histograms represent two independent experiments. g Ex vivo adhesion assay of T47D cells binding to lymphatic sinuses of six metastatic and five non-metastatic LNs from four and five patients, respectively (two-sided ratio paired t-test). LN sections were treated with anti-MGP or control antibody. The binding after control antibody was defined as 100% due to day-to-day variation. Example images show T47D cells binding after control vs. anti-MGP treatment to the same metastatic LN area. Adherent cells (some marked by yellow arrowheads) lie on top of tissue sections, focus adjusted to highlight cell adhesion. Scale bar: 50 μm. For box plots: center line = median; box = 25th–75th percentiles; whiskers = inner fences. Source data, non-significant p values and detailed experiment and n-numbers (biologically independent samples of cultured cells) are provided in the Source Data file.