Immunohistochemical studies on patterns of fibronectin and collagen type IV in normal human liver and hepatocellular carcinoma

ABSTRACT

The distribution of fibronectin [FN] and collagen type IV [coll IV] which are two main components of the basement membrane [BM], was investigated in normal human liver and hepatocellular carcinoma [HCC]. The peroxidase antiperoxidase [PAP] method was applied on paraffin embedded pepsin treated tissue, and the pattern of distribution of the two antigens was compared with the grade of differentiation of the tumor. Fibronectin was observed both extracellularly and intracellularly. It was either increased or decreased. In the more differentiated tumors, fibronectin was increased and it consisted of thin or thick stands. It was either periglandular, pericellular, sinusoidal or stromal-vascular. Decreased fibronectin was seen in undifferentiated HCC. Collagen type IV was localized only extracellularly. It exhibited two patterns of distribution in HCC, peritrabecular or periacinar and stromal-vascular. The finding that FN can be located pericellularly or within the acini supports the concept that FN is synthesized, at least in part by hepatoma cells. The peritrabecular and periacinar location of coll IV suggested a sinusoidal cell derivation of this antigen. The immunohistochemical staining pattern for BM in HCC reflects the differentiation of the tumor, with differentiated tumors showing a relatively intact BM and poorly differentiated tumors revealing a sharply defective BM