Figure 6.
Transcriptomic CRC Subtypes and CAFs as Drivers of AR to Cetuximab
(A) Transcriptomic subtypes in 13 BL and PD biopsy pairs. TA, transit amplifying; SL, stem-like.
(B) Volcano plot showing differential expression of growth factors in 5 cases from (A) undergoing CMS2>4 switches. Significance was assessed by paired t test.
(C) Changes in TGF-β and EMT transcriptomic signatures through CMS2>4 switches.
(D) Changes in fibroblast abundance through CMS2>4 switches based on MCP-counter analysis.
(E) Impact of CAF conditioned medium (CM) on the growth of DiFi (left panel) and LIM1215 (right panel) treated with 50 μg/mL CET for 5 days.
(F) Western blot analysis showing CAF CM rescue of pERK in DiFi (left panel) and LIM1215 (right panel) treated with 200 μg/mL CET for 2 h.
(G) mRNA expression (normalized counts) of growth factors (GFs) (left panel) and their receptors (right panel) in CAF, DiFi, and LIM1215 cells.
(H) Growth assay with 200 μg/mL CET and recombinant GF at a concentration of 20 ng/mL (FGF1/2), 10 ng/mL (TGF-β) and 50 ng/mL (HGF) for 5 days in DiFi (top panel) and LIM1215 (bottom panel).
(I) Western blot analysis of pERK with and without recombinant GF treatment in the presence or absence of 200 μg/mL CET in DiFi (top panel) and LIM1215 (bottom panel).
(J) Growth assay with CAF CM and combinations of CET, pan-FGFR inhibitor (FGFRi), and MET inhibitor (METi) for 5 days in DiFi (top panel) and LIM1215 (bottom panel).
(K) Western blot analysis of pERK after 2 h treatment with CAF CM and combinations of CET, FGFRi, and METi in DiFi (top panel) and LIM1215 (bottom panel).
(E, H, and J) All error bars ± SD of six replicates.