Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a yeast based p53 functional assay we previously demonstrated that the UVC-induced p53 mutation spectrum appears to be indistinguishable from the one observed in Non Melanoma Skin Cancer (NMSC). However, position 742 (codon 248, CpG site) represented the major hot spot in NMSC but was not found mutated in the yeast system. In order to determine whether UVC-induced mutagenic events may be facilitated at methylated cytosine (5mC), a yeast expression vector harbouring a human wild-type p53 cDNA (pLS76) was methylated in vitro by HpaII methylase. Methylation induced 98% protection to HpaII endonuclease. Unmethylated and methylated pLS76 vectors were then UVC irradiated (lambda(max): 254 nm) and transfected into a yeast strain containing the ADE2 gene regulated by a p53-responsive promoter. The results revealed that: (i) 5mC at HpaII sites did not cause any difference in the UVC-induced survival and/or mutagenicity; (ii) none of the 20 mutants derived from methylated pLS76 showed p53 mutations targeted at HpaII sites; (iii) the UVC-induced p53 mutation spectra derived from methylated and unmethylated pLS76 were indistinguishable not only when classes of mutations and hot spots were concerned, but also when compared through a rigorous statistical test to estimate their relatedness (P = 0.85); (iv) the presence of 5mC did not increase the formation of photo-lesions at codon 248, as determined by using a stop polymerase assay. Although based on a limited number of mutants, these results suggest that the mere presence of 5mC at position 742 does not cause a dramatic increase of its mutability after UVC irradiation. We propose that position 742 is a hot spot in NMSC either because of mutagenic events at 5mC caused by other UV components of solarlight and/or because not all the NMSC are directly correlated with UV mutagenesis but may have a "spontaneous" origin.
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PMID:5-methylcytosine at HpaII sites in p53 is not hypermutable after UVC irradiation. 1065 89

About 10% of melanoma cases have clinical factors indicative of hereditary cancer. CDKN2A is a major melanoma susceptibility gene in familial malignant melanoma. In this study a novel L94Q missense mutation of the CDKN2A gene is described in a melanoma kindred with two affected second-degree family members. To detect the mutation, polymerase chain reaction (PCR) amplification methods and direct sequencing were used. The presence of the mutation was confirmed by restriction fragment length polymorphism analysis after digestion of the PCR amplicons with the restriction endonuclease BspMI. The penetrance of the novel mutation was shown to be incomplete. Functional importance of the mutation was assumed from the protein p16 structure.
Melanoma Res 2003 Dec
PMID:A novel L94Q mutation in the CDKN2A gene in a melanoma kindred. 1464 19

Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignant tumors in the head and neck area. Melanoma-associated antigens A (MAGE-A) are strictly tumor-specific and are expressed in several types of tumors. To date, no studies have reported the potential of MAGE-A genes as markers for circulating tumor cells (CTCs) in patients with LSCC. The present study aimed to evaluate the expression and the possible prognostic significance of MAGE-A in the peripheral blood of patients with LSCC. In the present study, the expression of MAGE-A genes was determined by multiplex semi-nested PCR and restriction endonuclease treatment of the peripheral blood of patients with LSCC. The association between MAGE-A gene expression and clinicopathological parameters and prognosis was evaluated. The results demonstrated that the expression of MAGE-A was associated with the predictors that indicate poor prognosis. The expression levels of MAGE-A and each individual MAGE-A gene were also associated with a shorter overall survival time of patients with LSCC. In conclusion, the results of the present study suggested that the expression of MAGE-A genes may be a potential prognostic marker for patients with LSCC.
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PMID:MAGE-A genes as predictors of the outcome of laryngeal squamous cell carcinoma. 3279 12