CXCL8 and colon adenocarcinoma: Furthermore, using nuclear factor (NF)-kappa B reporter gene assays, TiO2-NPs-induced IL8 mRNA expression occurs in part through activation of NF-kappa B and p38 mitogen-activated protein kinase pathways in the human colon adenocarcinoma cell line Caco-2 [36] and those results demonstrate that TiO2-NPs cause an activation of inflammatory pathways in the human colon adenocarcinoma cell line Caco-2.