The Journal of pathology
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The Journal of pathology · Apr 2004
Gene expression profiles from hypertrophic scar fibroblasts before and after IL-6 stimulation.
The structural rearrangement of collagen fibres in hypertrophic scar causes abnormal contracture, low tensile strength, and raised scars, which cause functional impairment and disfigurement. It is hypothesized that changes in the genes of cytokines, extracellular matrix proteins, and proteins regulating programmed cell death are related to hypertrophic scar formation. To test this hypothesis, fibroblasts were cultured from hypertrophic scars and their response to interleukin-6 (IL-6) stimulation was studied by defining their gene expression profiles. ⋯ Values are means +/- SEM. The absence of any up-regulation of MMP-1 and MMP-3 in hypertrophic scar fibroblasts, in response to IL-6, suggests that suppression of matrix metalloproteinases may play a role in the excessive accumulation of collagen formed in hypertrophic scars. While the pathogenesis of abnormal hypertrophic scars remains poorly understood, the use of gene expression arrays may prove helpful in identifying the mechanisms responsible for this type of abnormal scar formation and in formulating an effective therapeutic protocol.
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The Journal of pathology · Apr 2004
Gastrointestinal stromal tumours (GISTs) negative for KIT (CD117 antigen) immunoreactivity.
Gastrointestinal stromal tumours (GISTs) are currently defined as mesenchymal tumours of the gastrointestinal tract that express KIT receptor tyrosine kinase. However, a small subgroup of tumours that fulfil the clinical and morphological criteria for GISTs lack KIT expression. So far, the biological features of these tumours have rarely been addressed. ⋯ None of these three tumours expressed KIT, while all specimens showed expression of PKC theta protein. These findings indicate that there is a subgroup of KIT-negative GISTs that exhibit the same morphological, cytogenetic, and molecular features as KIT-positive tumours. While intragenic PDGFRA activating mutations are present in some of these tumours, the oncogenic events underlying the pathogenesis of the others remain unknown.