(A) Transwell invasion chamber assay shows the invasive ability of siRNA negative control (siNC) and β6 knockdown HT-29 colon cancer cells (siβ6) after being co-cultured with NFs or CAFs for 24 h. The invasion capability of the CRC cells was positively correlated with β6 expression. Upon co-culture with NFs, the number of invasive cells significantly decreased in accordance with β6 knockdown in HT-29 cells (**P<0.01). This effect was also observed in CAF co-cultures (***P<0.001). Compared with the NFs, CAFs clearly promoted invasion of the negative control HT-29 cells (*P<0.05). (B) Transwell invasion chamber assay shows the invasive capability of mock transfected (Mock) and β6 transfected RKO CRC cells (β6 overexpression) after being co-cultured with NFs or CAFs for 24 h. The invasive capacity of CRC cells was positively correlated with β6 expression. Upon co-culture with NFs, the number of invasive cells significantly increased in accordance with the overexpression of β6 in RKO cells (**P<0.01). This effect was also in CAF co-cultures (***P<0.001). Compared with the NFs, CAFs clearly promoted the invasion of RKO cells overexpressing β6 (**P<0.01). (C) MMP3 ELISA shows that the four above-mentioned CRCs secreted MMP-3 after co-culture with NFs or CAFs for 24 h. CAFs promoted secretion of MMP-3 from CRC cells, and integrin αvβ6 increased the levels of secreted MMP-3 (*P<0.05, **P<0.01). (D) MMP-9 ELISA shows that the four above-mentioned CRC cells secreted MMP-9 after co-culture with NFs or CAFs for 24 h. CAFs promoted MMP-9 secretion from CRC cells, and integrin αvβ6 increased the levels of secreted MMP9 (*P<0.05,**P<0.01,***P<0.001). ***P<0.001, **P<0.01, *P<0.05; data are mean ± S.E.M. from three independent experiments.