Cytokeratin 7

The inbred BALB/c mice of either sex (8–10 weeks old, 20–25 g b.wt.) were administered urethane (Sigma-Aldrich, USA) at 1 g/kg b.wt. in saline once a week for four consecutive weeks intraperitoneally (Li et al., 2013 ). Mice were sacrificed by cervical dislocation at 8th, 16th and 24th week to track the development of lung adenocarcinoma lesions by histopathological analysis. Furthermore, the tumor development was confirmed by immunohistochemistry for Cytokeratin 7, Napsin-A and TTF-1(Cell Marque, USA) proteins as markers of lung adenocarcinoma.

Severity of cholestasis was assessed from histological examination of liver sections, and serum concentrations of albumin, alkaline phosphatase (ALKP) and total and conjugated bilirubin. Standard histological techniques were used to process liver samples. Sections obtained from paraffin-embedded liver tissues were stained with hematoxylin and eosin (H&E), and Masson trichrome for collagen. The following antibodies were used in this study to evaluate liver damage by immunohistochemistry: cytokeratin 7 (Cell-Marque, Germany, dilution 1:200), as a marker of ductular reaction of the damaged liver areas, and alpha-smooth muscle actin (ASMA, Cell Marque; Rocklin, CA, USA; dilution 1:100), as a marker of hepatic stellate cells activation. The immunohistochemical study was performed as described in Guido et al. [21 (link)]. The same pathologist, blinded to the study groups of origin of the liver sections, conducted all histological examinations.