Re-expression of procollagen type IIA in oral squamous cell carcinoma

There are two forms of procollagen type II (IIA and IIB), both of which are expressed during chondrogenesis. Procollagen type IIA also is present at sites of developmental epithelial-mesenchymal interaction. Malignant transformation is associated with disturbed epithelial-mesenchymal interaction and the reappearance of fetal characteristics. This study aims to determine whether or not procollagen type IIA is re-expressed in oral squamous cell carcinoma (OSCC). Immunoperoxidase techniques were applied to frozen and paraffin sections of OSCC (n = 30) and normal oral mucosa (n = 5). In the carcinoma group, strong cytoplasmic staining for collagen type II was present (25/30). Staining was weak or absent in the stroma, and absent from the normal oral mucosa. Frozen sections from 10 of the carcinoma cases which showed positive staining were incubated with antibodies specific for procollagen type IIA and visualised using immunofluorescence. Staining was evident in each case and was particularly strong in the region of the basement membrane. Slot-blot analysis of collagen extracts from OSCC supported the immunohistochemical findings. We conclude, therefore, that procollagen type IIA is re-expressed in OSCC.