Immunohistochemical evaluation of TGF-β and extracellular matrix proteins expression in rat squamous cell carcinomas

OBJECTIVE: The aim of this study was to establish a possible association between the degree of differentiation of squamous cell carcinomas (SCC) derived from rat oral tissues treated in vivo with the carcinogen 4NQO, and the expression of TGF-β on epithelial cells and the distribution of extracellular matrix proteins (laminin-collagen type IV).
MATERIALS AND METHODS: A parent tumour showing a spectrum of differentiation was used to establish clonal subpopulations that formed differentiated SCC and undifferentiated (spindle cell phenotype) tumours following transplantation to athymic mice.
RESULTS tmmunohistological findings revealed the absence of TGF-β staining on epithelial cells and extracellular matrix proteins in spindle cell tumours. In contrast, staining of SCC revealed a significant number of TGF-β positive cells and the presence of extracellular matrix proteins.
CONCLUSIONS: The findings suggested that there is a positive correlation between histological differentiation, TGF-β expression and the elaboration of extracellular matrix proteins.     

Distribution of T cells and signs of T-cell activation in the rheumatoid joint: implications for semiquantitative comparative histology

A prerequisite for comparative histology of synovial tissue by means of biopsies is insight into the distribution of a marker under study. This investigation focuses on the variation in the presence of T cells and signs of T-cell activation within the rheumatoid joint. For this purpose, multiple slides from several pieces of synovial tissue from different parts of a joint were stained and scored for the expression of CD3, CD25, HLA-DR, Ki67 and interferon-gamma. The variation in scores for the presence of T cells and markers of activation was more pronounced in slides prepared from different pieces of tissue than in slides from one piece of tissue. Based on multiple analysis of variance, methods are suggested to establish a reliable overall score for the expression of a certain marker within a joint. Following validation, such methods may prove to be useful by allowing semiquantitative histology of synovial tissue for studies on arthritis.