Fig. 6.

CD167a-Stat3 axis in the COL3-rich airway smooth muscle cell metastatic niche in lung. a Western blot evaluating the relative protein expression of CD167a, Stat3 and phosphotyrosine Stat3 (Y705) in parental T24 cells and our newly-established metastatic model (T24-LungMET). b, c Effects of COL3, and ASMC-conditioned media and CD167a/DDR1 kinase inhibitor (DDR1-IN-1; 10μM) on Stat3 and phosphotyrosine Stat3 protein expression, in T24 and PDX models. d Coupling CD167a co-IP with mass spectrometry to discover CD167a-interacting partners. Selected CD167a associated gene protein products (GPs) and their corresponding iBAQ values are listed. e Coupling co-IP and western blot to evaluate CD167a-HSP90 interaction, via co-IP using anti-HSP90 antibody followed by western blotting of CD167a in control and CD167a-overexpressing T24 cancer cells. f Effects of CD167a kinase inhibitor (DDR1-IN-1, 10μM) and HSP90 inhibitor (Geldanamycin, 5 μM) on CD167a-HSP90 complex formation. Control cells and CD167a-overexpressing T24 cancer cells were treated with COL3 in the absence or presence of indicated inhibitors for 24 h. Cell lysates were collected for co-immunoprecipitation assay using anti-HSP90 antibody. g PDX cells were cultured in control (-ASMC) or ASMCs conditioned media (+ASMC) with or without DDR1-IN-1 inhibitor (10 μM) for 24 h. Cell lysates were assessed for CD167a-HSP90 interaction by co-immunoprecipitation assay followed by western blot analysis. h, i Western blot analysis of Stat3 tyrosine phosphorylation upon treatment with ASMC-conditioned medium in the presence or absence of HSP90 inhibitor (+HSP90i, 1, 5, and 10 μM) in T24 and PDX models. j, k Western blot analysis of COL3-induced Stat3 tyrosine phosphorylation in T24 and PDX models upon treatment with CD167a/DDR1 kinase specific inhibitor (DDR1-IN-1, 10 μM) and Geldanamycin (HSP90i, 5 μM)