Transforming growth factor beta1 (TGFbeta1) is a multifunctional cytokine known to be involved in a number of human diseases. It is believed to play an important role in wound healing and repair, as it is a key regulator of the production and remodelling of the extracellular matrix through its effect on mesenchymal cells. Over the last few years, it has become evident that the signalling pathway of TGFbeta is complex with numerous receptor-ligand interactions, intracellular pathways and a number of mechanisms, which not only control the signalling but may also decide the response to the TGFbeta signal. This review focuses on TGFbeta1 signalling and the role that TGFbeta1 plays in wound healing, repair and scarring.

Early human fetuses regenerate cutaneous wounds perfectly without scarring. However, transforming growth factor-beta1 (TGF-beta1), the cytokine linked with scarring in mature tissue, is also present during fetal wound repair, albeit transiently. We present a comparison of response to TGF-beta1 by fibroblasts derived from early human fetal skin (non-scarring) and their mature (scarring) postnatal counterparts, which revealed that although fetal fibroblasts do indeed differentiate into myofibroblasts, this response is altogether more rapid and short-lived. Fetal fibroblasts also failed to exhibit the TGF-beta1-induced increase in collagen (mRNA and protein) demonstrated by their postnatal counterparts. Fetal cells exhibited a comparatively short-lived or rapid phosphorylation of several components of the TGF-beta1 signaling pathways: Smad2/3 and c-Jun N-terminal kinase. Unlike quiescent postnatal fibroblasts, quiescent fetal fibroblasts also phosphorylated extracellular signal-regulated kinases in response to TGF-beta1. These altered responses to TGF-beta1 may well contribute to the transition between perfect regeneration and scar formation seen during development.

Non-neoplastic epithelial lesions of the vulva (NNEDV) lichen sclerosus (LS) and squamous hyperplasia (SH) have been implicated in the pathogenesis of squamous cell carcinoma of the vulva (SCC). To date, there have been no recognisable precursor lesions for SCC associated with NNEDV. TP53 is the most frequent genetic change in human cancers and can indicate both aetiology and molecular pathogenesis of tumours. A total of 27 SCC patients underwent immunohistochemistry (IHC) and TP53 mutational analysis using microdissection and direct sequencing. There were 19 patients with areas of adjacent epidermis: 17 had NNEDV (four SCCs had more than one adjacent lesion) and two had normal epidermis. In all, 70.4% of the SCCs, 40% LS and 22.2% SH demonstrated overexpression of p53. In total, 77.8% of SCCs, 46.7% of LS and 22.2% SH demonstrated mutations in TP53, with the majority of lesions having a mutation in codon 136. Eight cases were identified where the same mutation was identified in the SCC and in the adjacent area. These data suggest that TP53 mutations develop in NNEDV and are intrinsic to the clonal evolution that leads to SCC. The type of mutation detected is more likely to occur due to endogenous cellular changes rather than exogenous carcinogen exposure. British Journal of Cancer (2003) Lichen sclerosus (LS) is an inflammatory disease of unknown aetiology and pathogenesis. It is a disorder of the skin, which is most common in the genital area but can occur anywhere on the body. It affects both sexes and all age groups. In a review by Meffert et al (1995) of 5207 patients, the female-to-male incidence was reported as 6 : 1, with genital involvement in 83% of cases. The majority of sufferers of anogenital LS are either middle-aged or elderly women. The predominant symptom in females is an intractable itch, which is often associated with dysuria, dyspareunia, dryness of the skin, labial stenosis or fusion and, in children, constipation (Laude et al, 1980).There have been many studies assessing the risk of squamous cell carcinoma of the vulva (SCC) in inflammatory diseases of the vulva. Wallace (1971) reported that 12 of 290 (4%) patients developed SCC following a history of LS during a 12-year period but further follow-up studies have shown a wide range of risk of progression (Hart et al, 1975;Meffert et al, 1995;Carlson et al, 1998). Others (Rueda et al, 1994;Scurry et al, 1997;Vilmer et al, 2000) have looked at the skin adjacent to SCC which, not uncommonly, shows epithelial disorders; the most common are LS and squamous hyperplasia (SH).The TP53 gene is located on chromosome 17p13.1; it consists of 11 exons with 10 introns. Exon 1 is noncoding, while exons 5 -8 are part of the highly evolutionarily conserved domain. Mutations in the TP53 gene are the most frequent genetic changes in human cancers, and the spectrum of mutations can indicate tumour aetiology and molecular pathogenesis (Levine et al, 1991;Greenblatt et al, 1994). In addition, a comparison of the mutation profile between malignant and potential p...

Wound healing is a complex process involving a number of processes. Fetal regeneration has been shown to have a number of differences compared to scar-forming healing. This review discusses the number of differences identified in fetal regeneration. Understanding these differences may result in new therapeutic targets which may reduce or even prevent scarring in adult healing.

No abstract