Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-melanoma skin cancer (NMSC) is by far the most frequently diagnosed cancer in Australia, and exposure to ultraviolet (UV) radiation is the primary cause. Both UVB and UVA radiation have been shown to cause DNA damage and immunosuppression, the important forms of biological damage that lead to NMSC. The DNA of keratinocytes absorbs UV radiation and produces photolesions such as cyclobutane pyrimidine dimers (CPDs). UV absorption by other chromophores results in the production of reactive oxygen species which cause oxidative damage to DNA such as 8-oxo-7,8-dihydroguanine (8oxoG). These photolesions can then, if not correctly repaired, lead to signature mutations. Reactive oxygen species also cause receptor activation and damage lipids and proteins. UV also deprives cells of adenosine triphosphate, and causes inflammation and cell cycle dysregulation. UV radiation has been shown to exert potent immunosuppressive effects on the skin through a number of molecular and cellular mechanisms. Many tumour suppressor genes and oncogenes have been studied and implicated in photocarcinogenesis, particularly p53, PTCH1, BRM and RAS. Clinical observations, histological analysis, as well as molecular and cytogenetic studies have shown actinic keratoses (AKs) and Bowen's disease (BD) to be precursors of squamous cell carcinomas (SCCs). Keratoacanthomas (KAs), a type of SCC, and AKs have frequently been observed to regress. Sun protective measures and sunscreens can reduce the incidence of NMSCs, although their effectiveness is limited by non-compliance. A large number of chemopreventive agents have been investigated, but to date none has been found to be clinically useful except within selected high risk groups. Therefore, further research is urgently required to find an ideal chemopreventive agent that is effective, safe, accessible and convenient.
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PMID:Non-melanoma skin cancer: carcinogenesis and chemoprevention. 2347 34

Non-melanoma skin cancer is the most frequently occurring type of cancer worldwide and is caused by epidermal carcinogenesis and malignant progression that involve dysregulated expression of proto-oncogenes and tumor suppressor genes. The proto-oncogene pituitary tumor-transforming gene 1 (PTTG1) is a ubiquitously expressed transcription factor that can promote enhanced proliferation of cultured epidermal keratinocytes. To investigate the potential roles of PTTG1 in epidermal carcinogenesis and malignant progression, the expression of PTTG1 was analysed by immunohistochemistry along with Ki67, keratin 10 (K10) and p53 in tissue samples of cutaneous squamous cell carcinomas (SCC), actinic keratoses (AK) and Bowen's disease (BD). Expression levels of PTTG1 were compared among these disease groups to test for correlations with proliferation, differentiation capacity or the existence of mutated tumor suppressor genes in each disease group. In each disease group, the expression levels of PTTG1 correlated positively with those of Ki67, although the differentiation status, measured by K10 expression, did not show any correlation. In contrast, the existence of mutated p53 proteins showed a positive correlation only in the SCC group. Moreover, the expression levels of PTTG1 in SCC did not correlate with known prognostic factors such as TNM staging or tumor thickness. These results suggest that PTTG1 may represent a proliferation marker associated with mutated p53 proteins but is not an informative predictor of poor clinical outcomes in SCC.
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PMID:Pituitary tumor-transforming gene 1 as a proliferation marker lacking prognostic value in cutaneous squamous cell carcinoma. 2348 47

The incidence of cutaneous squamous cell carcinoma (CSCC) and its precursor lesions argues the research for validating markers that would define the biomolecular mechanisms behind the potential progression and aggressiveness of these lesions. In this study, we analyzed the expression of p53, p16 and Ki67 in 91 cases of CSCC and its precursors in relation with the histological prognostic parameters. The quantification of the immunohistochemical reactions indicated superior significant differences for the studied markers in squamous cell carcinomas compared to keratinocytic intraepithelial neoplasia (KIN). P16 and Ki67 immunostaining for Bowen's disease were similar to those from poorly differentiated carcinomas. In this study, we found significant differences in p53 expression in relation to tumor grading and p16 expression in relation to tumor staging. Ki67 showed higher values in high-grade and advanced stage carcinomas. Positive reactions in preinvasive lesions as well as in CSCC support the sequential development and p53 and p16 involvement from the early stages of skin carcinogenesis.
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PMID:P53, p16 and Ki67 immunoexpression in cutaneous squamous cell carcinoma and its precursor lesions. 2783 60

Normal sun-exposed skin contains numerous epidermal patches that stain positive for p53 protein (p53 immunopositive patches, PIPs), which are considered potential early precursors of skin cancer. Although the TP53 gene is mutated in many PIPs, it is unclear whether PIPs contain any other cancer-related mutations. Here we report that PIPs, predominantly <3,000 p53 immunopositive cells in size, within normal chronically exposed skin contain mutations in multiple genes that are mutated in cutaneous squamous cell cancers. These mutations in the PIPs were not detected within the non-PIP epidermis of corresponding normal chronically exposed skin. Although some of these genetic alterations are clonal in the PIPs, many of the mutations are subclonal within these lesions. Similar mutations are seen in later precancers (actinic keratoses and Bowen's disease). Our results demonstrate that PIPs in chronically exposed skin contain multiple mutations in cancer-related genes. In addition, the results indicate that the clonal evolution of mutations that are seen within later precancerous lesions and in established malignancy can also occur in PIPs within normal human skin.
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PMID:Subclonal Evolution of Cancer-Related Gene Mutations in p53 Immunopositive Patches in Human Skin. 2927 45

Vulvar carcinomas represent 4% of all gynaecological cancers with 838 new cases in France in 2018. The precursor lesions of vulvar carcinomas are differentiated vulvar intraepithelial lesion (dVIN) in a context of lichen sclerosus and vulvar high-grade squamous intraepithelial lesion (HSIL) link to human papillomavirus (HPV) infection. Three typical clinical forms of HSIL are described: the Bowenoid papulosis, the Bowen's disease and the confluent VIN. Histopathology cannot differentiate effectively these two types of lesions. P16 and P53 immunostaining are valuable tools to respectively assess HPV infection and divide different types of dVIN. However, P53 immunostaining is still lacking sensibility to detect dVIN. First line therapies are medical treatment excluding the cases with a doubt of invasion. The gold standard treatment for dVIN and vulvar HSIL are respectively topical corticosteroids and imiquimod. Primary prevention for vulvar HSIL and dVIN are respectively HPV vaccination and early treatment of lichen sclerosus. Destructive therapy can be used in case of medical treatment failure such as CO2 laser, cryotherapy, dynamic phototherapy. Surgical indications should be carefully assessed between the risk of recurrence, the spread of the lesions, the aesthetic and functional aspect. Surgical procedures consist in either superficial vulvectomy or radical vulvectomy with or without flap reconstruction. Recurrence rate after surgery is around 20%.
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PMID:[Update on precursors of vulvar carcinoma]. 3316 2


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