Anthropometric measures in relation to Basal Cell Carcinoma: a longitudinal study

Background: The relationship between anthropometric indices and risk of basal cell carcinoma ( BCC) is largely unknown. We aimed to examine the association between anthropometric measures and development of BCC and to demonstrate whether adherence to World Health Organisation guidelines for body mass index, waist circumference, and waist/ hip ratio was associated with risk of BCC, independent of sun exposure. Methods: Study participants were participants in a community- based skin cancer prevention trial in Nambour, a town in southeast Queensland ( latitude 26 degrees S). In 1992, height, weight, and waist and hip circumferences were measured for all 1621 participants and weight was remeasured at the end of the trial in 1996. Prevalence proportion ratios were calculated using a log- binomial model to estimate the risk of BCC prior to or prevalent in 1992, while Poisson regression with robust error variances was used to estimate the relative risk of BCC during the follow- up period. Results: At baseline, 94 participants had a current BCC, and 202 had a history of BCC. During the 5- year follow- up period, 179 participants developed one or more new BCCs. We found no significant association between any of the anthropometric measures or indices and risk of BCC after controlling for potential confounding factors including sun exposure. There was a suggestion that short- term weight gain may increase the risk of developing BCC for women only. Conclusion: Adherence to World Health Organisation guidelines for body mass index, waist circumference and waist/ hip ratio is not significantly associated with occurrence of basal cell carcinomas of the skin.

De novo mutations of the Patched gene in nevoid basal cell carcinoma syndrome help to define the clinical phenotype

The demonstration that mutations in the Patched (PTCH) gene cause nevoid basal cell carcinoma syndrome (NBCCS) has led to the identification of the exact molecular lesion in a percentage of individuals with the syndrome, In addition, it has been possible to determine, through molecular analysis of parents and other relatives of these individuals, if the mutation is inherited or has arisen de novo, We have previously reported 28 mutations in individuals with NBCCS, and here we present an additional 4 novel mutations, We have also analyzed relatives of a number of the individuals in whom we have found mutations, In total we have identified 8 individuals who carry a de novo mutation in the PTCH gene, In 5 of these cases, clinical and radiological examination had not unequivocally ruled out a diagnosis in one of the parents, This helps to define the clinical phenotype and suggests that diagnostic criteria in this complex syndrome may require review. (C) 1997 Wiley-Liss, Inc.

CDKN2A is not the principal target of deletions on the short arm of chromosome 9 in neuroendocrine (Merkel cell) carcinoma of the skin

The majority of small-cell lung cancers (SCLCs) express p16 but not pRb, Given our previous study showing loss of pRb in Merkel cell carcinoma (MCC)/neuroendocrine carcinoma of the skin and the clinicopathological similarities between SCLC acid MCC, we wished to determine if this was also the case in MCC, Twenty-nine MCC specimens from 23 patients were examined for deletions at 10 loci on 9p and I on 9p. No loss of heterozygosity (LO H) was peen in 9 patients including 2 for which tumour and cell line DNAs were examined. Four patients had LOH for all informative loci on 9p, Ten tumours showed more limited regions of loss on 9p, and from these 2 common regions of deletion were determined, Half of all informative cases had LOH at D95168, the most telomeric marker examined, and 3 specimens showed loss of only D9S168, A second region (InFNA-D9S126) showed L0H in 10(44%) cases, and case MCC26 showed LOH for only D9S126, implicating genes centromeric of the CDKN2A locus. No mutations in the coding regions of p16 were seen in 7 cell lines tested, and reactivity to anti-p16 antibody was seen in all Il tumour specimens examined and in 6 of 7 cell lines from 6 patients. Furthermore, all cell lines examined reacted with anti-p 14' antibody, These results suggest that neither transcript of the CDKN2A locus is the target of deletions on 9p in MCC and imply the existence of tumour-suppressor genes mapping both centromeric and telomeric of this locus. (C) 2001 Wiley-Liss, Inc.

Melanocortin-1 receptor genotype is a risk factor for basal and squamous cell carcinoma

MC1R gene variants have previously been associated with red hair and fair skin color, moreover skin ultraviolet sensitivity and a strong association with melanoma has been demonstrated for three variant alleles that are active in influencing pigmentation: Arg151Cys, Arg160Trp, and Asp294His. This study has confirmed these pigmentary associations with MC1R genotype in a collection of 220 individuals drawn from the Nambour community in Queensland, Australia, 111 of whom were at high risk and 109 at low risk of basal cell squamous cell carcinoma. Comparative allele frequencies for nine MC1R variants that have been reported in the Caucasian population were determined for these two groups, and an association between prevalence of basal cell carcinoma, squamous cell carcinoma, solar keratosis and the same three active MC1R variant alleles was demonstrated [odds ratio=3.15 95% CI (1.7, 5.82)]. Three other commonly occurring variant alleles: Val60Leu, Val92Met, and Arg163Gln were identified as having a minimal impact on pigmentation phenotype as well as basal cell carcinoma and squamous cell carcinoma risk. A significant heterozygote effect was demonstrated where individuals carrying a single MC1R variant allele were more likely to have fair and sun sensitive skin as well as carriage of a solar lesion when compared with those individuals with a consensus MC1R genotype. After adjusting for the effects of pigmentation on the association between MC1R variant alleles and basal cell carcinoma and squamous cell carcinoma risk, the association persisted, confirming that presence of at least one variant allele remains informative in terms of predicting risk for developing a solar-induced skin lesion beyond that information gained through observation of pigmentation phenotype.

Characterization of a novel gene, STAG1/PMEPA1, upregulated in renal cell carcinoma and other solid tumors

Using differential display-polymerase chain reaction, we identified a novel gene sequence, designated solid tumor-associated gene 1 (STAG1), that is upregulated in renal cell carcinoma (RCC). The full-length cDNA (4839 bp) encompassed the recently reported androgen-regulated prostatic cDNA PMEPA1 and so we refer to this gene as STAG1/PMEPA1, Two STAG1/PMEPA1 mRNA transcripts of approximately 2.7 an 5 kb, with identical coding regions but variant 3' untranslated regions, were predominantly expressed in normal prostate tissue and at lower levels in the ovary. The expression of this gene was upregulated in 87% of RCC samples and also was upregulated in stomach and rectal adenocarcinomas. In contrast, STAG1/PMEPA1 expression was barely detectable in leukemia and lymphoma samples, Analysis of expressed sequence tag databases showed that STAG1/PMEPA1 also was expressed in pancreatic, endometrial, and prostatic adenocarcinomas. The STAG1/PMEPA1 cDNA encodes a 287-amino-acid protein containing a putative transmembrane domain and motifs that suggest that it may bind src homology 3- and tryptophan tryptophan domain-containing proteins. This protein shows 67% identity to the protein encoded by the chromosome 18 open reading frame 1 gene. Translation of STAG1/PMEPA1 mRNA in vitro showed two products of 36 and 39 kDa, respectively, suggesting that translation may initiate at more than one site. Comparison to genomic clones showed that STAG1/PMEPA1 was located on chromosome 20q13 between microsatellite markers D20S183 and D20S173 and spanned four exons and three introns. The upregulation of this gene in several solid tumors indicated that it may play an important role in tumorigenesis. (C) 2001 Wiley-Liss, Inc.

TTYH2, a human homologue of the Drosophila melanogaster gene tweety, is located on 17q24 and upregulated in renal cell carcinoma

Using differential display PCR, we identified a novel gene upregulated in renal cell carcinoma. Characterization of the full-length cDNA and gene revealed that the encoded protein is a human homologue of the Drosophila melanogaster Tweety protein, and so we have termed the novel protein TTYH2. The orthologous mouse cDNA was also identified and the predicted mouse protein is 81% identical to the human protein. The encoded human TTYH2 protein is 534 amino acids and, like the other members of the tweety-related protein family, is a putative cell surface protein with five transmembrane regions. TTYH2 is located at 17q24; it is expressed most highly in brain and testis and at lower levels in heart, ovary, spleen, and peripheral blood leukocytes. Expression of this gene is upregulated in 13 of 16 (81%) renal cell carcinoma samples examined. In addition to a putative role in brain and testis, the overexpression of TTYH2 in renal cell carcinoma suggests that it may have an important role in kidney tumorigenesis.

Alterations in gene expression and activity during squamous cell carcinoma development

This study focuses on characterizing the genetic and biological alterations associated with squamous cell carcinoma development. Normal human epidermal keratinocytes (HEKs), cells isolated from a preneoplastic lesion (IEC-1), and two neoplastic cell lines, SCC-25 and COLD-16, were grown as raft cultures, and their gene expression profiles were screened using cDNA arrays. Our data indicated that the expression levels of at least 37 genes were significantly (P less than or equal to 0.05; 1.9% of genes screened) altered in neoplastic cells compared with normal cells. Of these genes, 10 genes were up-regulated and 27 genes were down-regulated in the neoplastic cells. In addition, 51% of the genes altered in the neoplastic cells were already altered in the preneoplastic IEC-1 cells. Immunohistochemical staining of patient tumors was used to verify the cDNA array analysis. Our analysis indicated that alterations in genes associated with extracellular matrix production and apoptosis are disrupted in preneoplastic cells, whereas later stages of neoplasia are associated with alterations in gene expression for genes involved in DNA repair or epidermal growth factor (EGF) receptor/mitogen-activated protein kinase kinase (MAPKK)/MAPK/activator protein-1 (AP-1) signaling. Subsequent functional analysis of the alterations in expression of the EGF receptor/MAPKK/MAPK/AP-1 genes suggested they did not contribute to the neoplastic phenotype.

Isolation (from a basal cell carcinoma) of a functionally distinct fibroblast-like cell type that overexpresses Ptch

In this study we report on the isolation and characterization of a nonepithelial, nontumorigenic cell type (BCC1) derived from a basal cell carcinoma from a patient. The BCC1 cells share many characteristics with dermal fibroblasts, such as the expression of vimentin, lack of expression of cytokeratins, and insensitivity to agents that cause growth inhibition and differentiation of epithelial cells; however, significant differences between BCC1 cells and fibroblasts also exist. For example, BCC1 cells are stimulated to undergo DNA synthesis in response to interferon-gamma, whereas dermal fibroblasts are not. More over, BCC1 cells overexpress the basal cell carcinoma-specific genes ptch and ptch2 . These data indicate that basal cell carcinomas are associated with a functionally distinct population of fibroblast-like cells that overexpress known tumor-specific markers (ptch and ptch2 ).

Renal cell carcinoma may adapt to and overcome anti-angiogenic intervention with thalidomide

Objective To report on the failure of thalidomide to inhibit tumour growth in an animal model of human renal cell carcinoma (RCC). Materials and methods An orthotopic xenograft model of human RCC was used in which tumour cells were implanted in the left kidney of male 'severe combined immunodeficient' mice. Thalidomide was administered by intraperitoneal injection and after 34 days the mice were killed. The extent of tumour growth was compared in treated and untreated mice. Total RNA was extracted from both tumour-affected and contralateral kidneys, and analysed by reverse transcription-polymerase chain reaction for various genes implicated in angiogenesis and metastasis in RCC. Results Thalidomide failed to inhibit the growth of xenograft tumours. The expression of angiogenic genes, e.g. vascular endothelial growth factor and fibroblast growth factor type 2 (FGF-2) within normal and tumour-affected kidney tissue was not reduced by thalidomide. Intratumoral transcription Of beta(3)-integrin, a critical component of angiogenesis, was significantly increased in response to thalidomide treatment (P

E2F modulates keratinocyte squamous differentiation. Implications for E2F inhibition in squamous cell carcinoma

E2F regulation is essential for normal cell cycle progression. Therefore, it is not surprising that squamous cell carcinoma cell lines (SCC) overexpress E2F1 and exhibit deregulated E2F activity when compared with normal keratinocytes. Indeed, deliberate E2F1 deregulation has been shown to induce hyperplasia and skin tumor formation. In this study, we report on a dual role for E2F as a mediator of keratinocyte proliferation and modulator of squamous differentiation. Overexpression of E2F isoforms in confluent primary keratinocyte cultures resulted in suppression of differentiation-associated markers. Moreover, we found that the DNA binding domain and the trans-activation domain of E2F1 are important in mediating suppression of differentiation. Use of a dominant/negative form of E2F1 ( E2F d/n) found that E2F inhibition alone is sufficient to suppress the activity of proliferation-associated markers but is not capable of inducing differentiation markers. However, if the E2F d/n is expressed in differentiated keratinocytes, differentiation marker activity is further induced, suggesting that E2F may act as a modulator of squamous differentiation. We therefore examined the effects of E2F d/n in a differentiation- insensitive SCC cell line. We found that treatment with the differentiating agent, 12-O-tetradecanoyl- phorbol-13-acetate (TPA), or expression of E2F d/n alone had no effect on differentiation markers. However, a combination of E2F d/n + TPA induced the expression of differentiation markers. Combined, these data indicate that E2F may play a key role in keratinocyte differentiation. These data also illustrate the unique potential of anti-E2F therapies in arresting proliferation and inducing differentiation of SCCs.