Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As dermatologists, we have all been active in educating patients about sun awareness and sun protection. This is even more important for children, as childhood exposure to ultraviolet light is a significant risk for both melanoma and nonmelanoma skin cancers. The importance of an educational approach in appropriate sun awareness in childhood is further underscored by the recent findings by Rivers et al., in the Vancouver Moles Cohort study, presented at the 1999 American Academy of Dermatology meeting. In a placebo-controlled trial, the findings of Rivers et al. clearly demonstrated that the use of sunscreens can significantly decrease the formation of nevae in children, providing further evidence to support sun awareness education initiatives. The lead article by Gooderham and Guenther in the Basic and Clinical Sciences section evaluates the effectiveness of a particular sun awareness program, and gives valuable insights into how more effective approaches may be used in the future. In addition to ultraviolet light playing a causal role in cutaneous malignancies, it is known to induce a number of other skin problems. One particularly difficult group of disorders is the photosensitive dermatoses, including solar urticaria. Bissonnette et al. describe an innovative approach to the management of refractory solar urticaria with plasma exchange. In the Grand Rounds section, Strauss et al. review the case of an acute SLE and give an insightful discussion related to bullous eruptions in acutely ill children. The mechanism of ultraviolet-light-induced carcinogenesis involves UV-induced DNA damage. Over the past decade, it has become clear that tumour suppressor genes can regulate these processes. In the Review section, Tron et al. discuss the role of the suppressor gene p53, which is mutated or lost in nonmelanoma skin cancer. P53 is crucial in protecting keratinocytes from the harmful effects of ultraviolet radiation, and in their instructive article, these authors use gene-targeted mutant mice lacking p53 to further evaluate the role in UV-induced DNA damage. With the warm weather upon us, we are spending more time in the outdoors and, as a result, are exposed to a vast number of environmental onslaughts. These include such things as Rickettsial disease, summarized in our CME section Summary Notes. Furthermore, in a comprehensive review, Dr. Sasseville examines another outdoor threat as he delineates the wide spectrum of plant contact dermatitis. This represents an important and in-depth reference on phytodermatitis. Our specialty, and indeed all of medicine, is being dramatically altered by recent advances in our understanding of disease at a molecular level. This new understanding of disease has led to the potential of modifying gene expression through the use of gene therapy. This is particularly attractive in skin disease, where gene therapy can be delivered quite readily through the skin. This advancement is insightfully discussed in the article by Somani et al., "Gene Therapy and Dermatology," which is both valuable for the cognoscenti and noncognoscenti alike, and serves as an important reference work in this area.
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PMID:Editorial 1038 44

Many studies using different approaches and sets of data have concluded that there is a significantly increased risk of malignant melanoma in patients with atypical moles. For clinical identification, the features of ABCD's (Asymmetry, Border, Colour, Dimension) are used, the "ugly duckling" sign (the naevus that does not resemble its "brother naevi"), dermatoscopy and digital approaches. After excision, histologic criteria are used to identify naevi with architectural changes. It has recently been possible to identify allelic losses within known tumour suppressor genes in microdissected atypical moles, using microdissection and loss of heterozygosity analysis, thus providing additional evidence for the concept of the atypical mole as a precursor lesion of melanoma.
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PMID:[The atypical nevus: a risk situation?]. 1041 20

Advanced malignancy in tumours represents the phenotypic endpoint of successive genetic lesions that affect the function and regulation of oncogenes and tumour-suppressor genes. The established tumour is maintained through complex and poorly understood host-tumour interactions that guide processes such as angiogenesis and immune sequestration. The many different genetic alterations that accompany tumour genesis raise questions as to whether experimental cancer-promoting mutations remain relevant during tumour maintenance. Here we show that melanoma genesis and maintenance are strictly dependent upon expression of H-RasV12G in a doxycycline-inducible H-Ras12G mouse melanoma model null for the tumour suppressor INK4a. Withdrawal of doxycycline and H-RasV12G down-regulation resulted in clinical and histological regression of primary and explanted tumours. The initial stages of regression involved marked apoptosis in the tumour cells and host-derived endothelial cells. Although the regulation of vascular endothelial growth factor (VEGF) was found to be Ras-dependent in vitro, the failure of persistent endogenous and enforced VEGF expression to sustain tumour viability indicates that the tumour-maintaining actions of activated Ras extend beyond the regulation of VEGF expression in vivo. Our results provide genetic evidence that H-RasV12G is important in both the genesis and maintenance of solid tumours.
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PMID:Essential role for oncogenic Ras in tumour maintenance. 1044 Mar 78

CD146, also known as Mel-CAM, MUC18, A32 antigen, and S-Endo-1, is a membrane glycoprotein which functions as a Ca(2+)-independent cell adhesion molecule involved in heterophilic cell-cell interactions. Based on homology of the nucleotide sequence, CD146 is classified as a member of the immunoglobulin gene superfamily, since it contains the characteristic V-V-C2-C2-C2 immunoglobulin-like domain structure. Using immunohistochemistry with CD146-specific antibodies, CD146 expression has been demonstrated in a relatively limited spectrum of normal human tissues and malignant neoplasms. The lineage-specific expression pattern of CD146 can be useful in the differential diagnosis of certain lesions including melanomas and various types of gestational trophoblastic lesions. Although the biological role of CD146 in normal tissue and malignant tumours remains unclear, CD146 has been suggested to play an important role in tumour progression, implantation and placentation. CD146 expression can promote tumour progression in human melanoma, possibly through enhanced interaction between melanoma cells and endothelial cells. In contrast, CD146 may act as a tumour suppressor in breast carcinoma. CD146 expression is frequently lost in breast carcinomas and overexpression of CD146 in breast carcinoma cells results in a more cohesive cell growth and the formation of smaller tumours in nude mice. During implantation and placentation, CD146 expressed by the intermediate trophoblast in the placental site binds to its putative receptor in uterine smooth muscle cells and limits trophoblastic invasion in the myometrium. In conclusion, CD146 is a recently identified novel cell adhesion molecule and its biological functions and role as a diagnostic marker in pathology are now being recognized. Identification of the receptor for CD146 and the development of experimental models that can account for the complex interactions between CD146-expressing cells and their microenvironment are needed to investigate further the functions of this molecule in biology and in pathological states.
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PMID:The role of CD146 (Mel-CAM) in biology and pathology. 1045 81

Eighteen human congenital melanocytic naevi (CMN) from 17 patients were screened for activating point mutations in the oncogenes N-ras and CDK4 and for sequence variants in the MC1R gene by combined RFLP-PCR/SSCP analysis. In addition, all lesions were screened for deletions and point mutations in the tumour suppressor genes p53 and p16INK4a (CDKN2A) by combined multiplex PCR/SSCP analysis. Positive screening data were specified by sequencing of the corresponding PCR product. Activating point mutations in the N-ras gene (nine CAA (Gln) to AAA (Lys) transversions and one CAA (Gln) to CGA (Arg) transition at codon 61) were detected at high frequency (56%). Furthermore, three missense mutations (V92M) and two silent mutations (CGA (Arg) to CGG (Arg), codon 213, exon 6) were found in the MC1R and p53 genes, respectively. No mutations were found in p16 or CDK4. The activated N-ras oncogene, which is also found in human cutaneous melanomas, may constitute a potential risk factor for melanoma formation within CMN.
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PMID:Mutational analysis of the N-ras, p53, p16INK4a, CDK4, and MC1R genes in human congenital melanocytic naevi. 1046 11

During the initiation and progression of malignant melanoma a series of genetic events accumulate, including alterations of chromosome 11q. Recently, an important tumour suppressor gene, the multiple endocrine neoplasia type 1 (MEN1) gene, has been mapped on 11q13 and has been cloned. To assess whether the MEN1 region is involved in tumour initiation and progression, we analysed 23 primary cutaneous melanomas and 17 metastases for loss of heterozygosity (LOH) using two informative polymorphic markers closely linked to the MEN1 gene (PYGM and D11S449). To search for mutations within the gene, single-strand conformation polymorphism (SSCP) analysis was performed using 13 primer sets with designed intronic sequences to amplify the MEN1 coding sequence exons 2 to 10. None of the cases showed LOH at the MEN1 gene locus. By SSCP analysis, no aberrant bands were identified on exons 3 to 10. Analysis of exon 2 revealed the presence of aberrant bands in two of the analysed melanomas. Sequencing analysis revealed a genetic polymorphism at S145S (AGC-->ACT) in both sections. None of the cases analysed showed MEN1 gene mutations. This study represents the first genetic analysis of the MEN1 gene in sporadic melanomas. Our data demonstrate no evidence of deletion or mutation of the MEN1 gene in primary or metastatic melanoma. Therefore, MEN1 gene alterations appear not to be associated with tumorigenesis of malignant melanoma. The MEN1 gene appears to be a highly specific tumour suppressor gene only involving tumours within the spectrum of MEN1 disease.
Melanoma Res 1999 Jun
PMID:Mutation analysis of the MEN1 tumour suppressor gene in malignant melanoma. 1046 80

Malignant melanoma is the deadliest form of skin cancer. Previous studies have shown that the incidence of ras mutation increases with progression of melanoma, but that such mutations may not be present in the earliest radial growth phase melanomas. Recently it has been proposed that introduction of ras mutations into cells deficient in tumour suppressor genes such as p16 (INK4a) is sufficient to induce characteristics of cellular transformation such as anchorage-independent growth and tumour formation in vivo. To test this hypothesis in human melanoma, mutant N-ras, mutant H-ras or wild-type H-ras genes were transfected by electroporation into WM35 cells, a p16-deficient human melanoma cell line of low invasive potential. Increased expression of mutant ras p21 enhanced anchorage-dependent cell growth on tissue culture plastic. In addition, overexpression of mutant N-ras and H-ras, but not of wild-type H-ras, increased the experimental invasive potential, inducing anchorage-independent growth in soft agar, increasing cell motility measured by time-lapse video microscopy, and increasing invasiveness through reconstituted basement membranes. Finally, overexpression of mutant H-ras in melanoma cells was shown to increase tumorigenicity and to induce cachexia when H-ras transfected cell lines were injected subcutaneously in severe combined immunodeficiency (SCID) mice. Thus the addition of activating ras mutations to a melanoma cell line already deficient in p16 leads to enhanced proliferation, survival and migration in vitro and to enhanced subcutaneous tumour formation in vivo. This phenotype is typical of the behaviour of vertical growth phase (VGP) melanoma, and we propose that activation of the ras signalling pathway in the presence of deletions in p16 or related tumour suppressors can induce the VGP melanoma phenotype.
Melanoma Res 1999 Jun
PMID:Overexpression of mutant ras in human melanoma increases invasiveness, proliferation and anchorage-independent growth in vitro and induces tumour formation and cachexia in vivo. 1046 84

Human papillomaviruses (HPV) are increasingly recognised as important human carcinogens. The best established association with human malignancy is that of high-risk mucosal HPV types and anogenital cancer. HPV-induced transformation of anogenital epithelia has been the subject of intense research which has identified the cellular tumour suppressor gene products, p53 and pRB, as important targets for the viral oncoproteins E6 and E7 respectively. Certain HPV types are also strongly associated with the development of non-melanoma skin cancer in the inherited disorder epidermodysplasia verruciformis (EV). However, in contrast with anogenital malignancy the oncogenic mechanisms of EV-HPV types remain uncertain, and there appears to be a crucial additional requirement for ultraviolet radiation. Cutaneous HPV types in the general population are predominantly associated with benign viral warts, but a role in non-melanoma skin cancer has recently been postulated. Polymerase chain reaction based HPV detection techniques have shown a high prevalence of HPV DNA, particularly in skin cancers from immunosuppressed patients and to a lesser extent in malignancies from otherwise immunocompetent individuals. No particular HPV type has yet emerged as predominant, and the role of HPV in cutaneous malignancy is unclear at present. It remains to be established whether HPV plays an active or purely a passenger role in the evolution of non-melanoma skin cancer.
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PMID:Human papillomavirus and the development of non-melanoma skin cancer. 1047 13

Retinoblastoma binding protein 1 (RBP-1) is a 143-kDa nuclear phosphoprotein that promotes cell growth by inhibiting the product of retinoblastoma tumour suppressor gene (pRB). We recently found that RBP-1 contains KASIFLK, a heptameric peptide (250-256) recognized by human antibodies and overexpressed by breast cancer cells. In the present study, we demonstrate that human T-cells stimulated with RBP-1 decameric peptides containing KASIFLK can kill human breast cancer cells. These decamers, GLQKASIFLK (247-256) and KASIFLKTRV (250-259), have anchor motifs for both HLA-A2 and HLA-A3. Peripheral blood lymphocytes from 41 normal donors were stimulated by these peptides in culture media containing 15 IU ml(-1) interleukin-2, 25 IU ml(-1) interleukin-7 and 500 IU ml(-1) granulocyte-macrophage colony-stimulating factor. Cytotoxic activity of the T-cells was assessed against autologous B lymphoblastoid cells pulsed with each peptide. Stimulation by GLQKASIFLK generated specific cytotoxic T lymphocyte (CTL) lines from HLA-A2, A3 donors, HLA-A2 donors and HLA-A3 donors. Stimulation with KASIFLKTRV generated specific CTL lines from HLA-A2 donors. No HLA-A2-, A3 CTL line showed specific cytotoxicity against these target cells. These CTL lines were also cytotoxic against HLA-A2 and HLA-A3 breast cancer cells but not against normal fibroblastoid cell lines, normal epidermal cell lines, or a melanoma cell line. RBP-1 peptide antigens may be of clinical significance as a potential peptide vaccine against human breast cancer.
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PMID:Cytotoxic T lymphocytes that recognize decameric peptide sequences of retinoblastoma binding protein 1 (RBP-1) associated with human breast cancer. 1049 63

Inherited mutations in the CDKN2A/INK4a/MTS1 tumour suppressor gene on chromosome 9p21 are associated with familial predisposition to melanoma and other tumour types. Nonsense and missense mutations are also found in a variety of sporadic cancers, and over 140 sequence variants have already been recorded in the literature. In assessing the relevance of these variants and for counselling members of affected families, it is important to distinguish inactivating mutations from harmless polymorphisms. Existing functional assays have frequently reached conflicting conclusions and no single test appears adequate. Here we evaluate a number of alternatives including a novel assay based on retroviral delivery of p16INK4a cDNAs into human diploid fibroblasts. Among the 17 sequence variants analysed, three distinct categories can be distinguished: those that abrogate the binding of p16INK4a to CDK4 and CDK6, those that alter the properties of the protein without preventing it from interacting with CDKs, and those that have no discernible effect on protein function. These distinctions can be rationalized by considering the impact of the amino acid changes on the three-dimensional structure of the protein.
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PMID:Functional evaluation of tumour-specific variants of p16INK4a/CDKN2A: correlation with protein structure information. 1049 96


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