The B-MYB proto-oncogene is a transcription factor belonging to the MYB family that is frequently overexpressed or amplified in different types of human malignancies. While it is suspected that B-MYB ...plays a role in human cancer, there is still no direct evidence of its causative role. Looking for mutations of the B-MYB gene in human cell lines and primary cancer samples, we frequently isolated two nonsynonymous B-MYB polymorphic variants (rs2070235 and rs11556379). Compared to the wild-type protein, the B-MYB isoforms display altered conformation, impaired regulation of target genes and decreased antiapoptotic activity, suggesting that they are hypomorphic variants of the major allele. Importantly, the B-MYB polymorphisms are common; rs2070235 and rs11556379 are found, depending on the ethnic background, in 10-50% of human subjects. We postulated that, if B-MYB activity is important for transformation, the presence of common, hypomorphic variants might modify cancer risk. Indeed, the B-MYB polymorphisms are underrepresented in 419 cancer patients compared to 230 controls (odds ratio 0.53; (95%) confidence interval 0.385-0.755; P=0.001). This data imply that a large fraction of the human population is carrier of B-MYB alleles that might be associated with a reduced risk of developing neoplastic disease.
Background
Many melanoma observational studies have been carried out across different countries and geographic areas using heterogeneous assessments of epidemiologic risk factors and clinical ...variables.
Aim
To develop a consensus questionnaire to standardize epidemiologic and clinical data collection for melanoma risk assessment.
Methods
We used a stepwise strategy that included: compilation of variables from case–control datasets collected at various centres of the MelaNostrum Consortium; integration of variables from published case–control studies; consensus discussion of the collected items by MelaNostrum members; revision by independent experts; addition of online tools and image‐based charts; questionnaire testing across centres and generation of a final draft.
Results
We developed a core consensus questionnaire (MelanoQ) that includes four separate sections: A. general and demographic data; B. phenotypic and ultraviolet radiation exposure risk factors and lifestyle habits; C. clinical examination, medical and family history; and D. diagnostic data on melanoma (cases only). Accompanying online tools, informative tables, and image‐based charts aid standardization. Different subsections of the questionnaire are designed for self‐administration, patient interviews performed by a physician or study nurse, and data collection from medical records.
Conclusions
The MelanoQ questionnaire is a useful tool for the collection and standardization of epidemiologic and clinical data across different studies, centres, cultures and languages. This will expedite ongoing efforts to compile high‐quality data for pooled analyses or meta‐analyses and offer a solid base for the design of clinical, epidemiologic and translational studies on melanoma.
A single-nucleotide polymorphism (SNP) in the promoter of the MDM2 gene, SNP309 (a T→G change), was recently implicated in the early onset of cancer in individuals with Li-Fraumeni syndrome and of ...sporadic soft-tissue sarcoma. SNP309 induces an increase in the level of Mdm2 protein, which causes attenuation of the p53 pathway. To investigate the effect of this polymorphism in colorectal cancer pathogenesis, we genotyped 153 colorectal cancer patients who were randomly selected from among 330 consecutive patients stratified according to p53 mutation status and age at diagnosis, for alleles of MDM2–SNP309. Among the 77 patients with p53 wild-type tumors, the median age at colorectal cancer diagnosis was 71.5 years for patients with the T/T genotype and 61.0 years for patients with SNP309 (T/G or G/G genotype) (estimated difference between medians Hodges–Lehmann method = 8.0 years, 95% confidence interval = 1.0 to 16.0 years; P = .03 two-sided Wilcoxon rank sum test). Our data indicate that MDM2–SNP309 is a modifier of the age at colorectal cancer onset for patients whose tumors have a wild-type p53 gene.
Little is known on whether melanocortin 1 receptor (MC1R) associated cutaneous melanoma (CM) risk varies depending on histological subtype and body site, and whether tumour thickness at diagnosis ...(the most important prognostic factor for CM patients) differs between MC1R variant carriers and wild-type individuals. We studied the association between MC1R variants and CM risk by histological subtype, body site, and Breslow thickness, using the database of the M-SKIP project. We pooled individual data from 15 case-control studies conducted during 2005-2015 in Europe and the USA. Study-specific, multi-adjusted odds ratios were pooled into summary odds ratios (SOR) and 95% confidence intervals (CI) using random-effects models. Six thousand eight hundred ninety-one CM cases and 5555 controls were included. CM risk was increased among MC1R variant carriers vs. wild-type individuals. The increase in risk was comparable across histological subtypes (SOR for any variant vs. wild-type ranged between 1.57 and 1.70, always statistical significant) except acral lentiginous melanoma (ALM), for which no association emerged; and slightly greater on chronically (1.74, 95% CI 1.47-2.07) than intermittently (1.55, 95% CI 1.34-1.78) sun-exposed skin. CM risk was greater for those carrying 'R' vs. 'r' variants; correlated with the number of variants; and was more evident among individuals not showing the red hair colour phenotype. Breslow thickness was not associated with MC1R status. MC1R variants were associated with an increased risk of CM of any histological subtype (except ALM) and occurring on both chronically and intermittently sun-exposed skin.
Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disease develops in severe combined immunodeficient (SCID) mice inoculated with peripheral blood mononuclear cells (PBMC) from EBV(+) ...individuals (SCID/hu mice). In this study, we investigated the contribution of EBV reactivation and de novo infection of B lymphocytes to tumor outgrowth in SCID/hu mice. Evaluation of BZLF-1, an early EBV activation transcript, in cells recovered from the mouse peritoneal cavity within 16 days following PBMC transfer did not reveal EBV reactivation, while BZLF-1 expression was only detected in tumor masses or in vitro established lymphoblastoid cell lines. To confirm these data by a different strategy, we coinjected PBMC from seropositive donors with purified B cells from seronegative donors of different sex. Fluorescence in situ hydridization analysis of the resulting tumor masses disclosed that the overwhelming majority of lymphoma cells originated from the seropositive donor, implying that no substantial in vivo production and transmission of virus had occurred. Further, treatment of SCID/hu mice with ganciclovir did not prevent lymphoma development. Our results suggest that in the SCID/hu mouse, early EBV replication and secondary infection of bystander B cells does not occur, and that the direct outgrowth of the transformed B lymphocytes present within the PBMC inoculum is the predominant mechanism, which leads to lymphoma generation in this experimental model.
The recent identification of major genomic rearrangements in breast and breast/ovarian cancer families has widened the mutational spectrum of the BRCA1 gene, thus increasing the number of informative ...patients who can benefit from molecular screening. Numerous types of alterations have been identified in different populations with variable frequencies, probably due to both ethnic diversity and the technical approach employed. In fact, although several methods have been successfully used to detect large genomic deletions and insertions, most are laborious, time-consuming, and of variable sensitivity. In order to estimate the contribution of BRCA1 genomic rearrangements to breast/ovarian cancer predisposition in Italian families, we applied, for the first time as a diagnostic tool, the recently described multiplex ligation-dependent probe amplification (MLPA) methodology. Among the 37 hereditary breast/ovarian cancer (HBOC) families selected, all had a high prior probability of BRCA1 mutation, and 15 were previously shown to carry a mutation in either the BRCA2 (five families) or BRCA1 gene (10 families, including one genomic rearrangement). The application of BRCA1-MLPA to the remaining 22 uninformative families allowed the identification of five additional genomic rearrangements. Moreover, we observed that loss of constitutive heterozygosity of polymorphic markers in linkage disequilibrium is predictive of such BRCA1 alterations. By means of this approach, we demonstrate that BRCA1 genomic deletions account for more than one-third (6/15) of the pathogenic BRCA1 mutations in our series. We therefore propose to systematically include MLPA in the BRCA1 mutational analysis of breast/ovarian cancer families.
Recent studies have shown that the G-allele of MDM2 SNP309 (T/G) in the p53 tumour suppressor pathway can accelerate tumorigenesis and alter the risk of various cancers in women and not in men. In ...this report, data are presented from two independent groups of patients that suggest that the G-allele of SNP309 accelerates colorectal tumour formation only in women, and that lend further support to the model that primarily female-specific hormones, such as oestrogen, could either directly or indirectly allow for the G-allele of SNP309 to accelerate tumour formation in women.
Abstract The p53 gene is rarely mutated in neuroblastoma, but codon 72 polymorphism that modulates its proapoptotic activity might influence cancer risk and clinical outcome. We investigated whether ...this polymorphism affects neuroblastoma risk and disease outcome and assessed the biologic effects of the p53-72R and p53-72P isoforms in p53-null cells. Comparison of 288 healthy subjects and 286 neuroblastoma patients revealed that the p53-72 polymorphism had no significant impact on the risk of developing neuroblastoma; however, patients with the Pro/Pro genotype had a shorter survival than those with the Arg/Arg or the Arg/Pro genotypes even in the stage 3 and 4 subgroup without MYCN amplification. By Cox regression analysis, the p53 Pro/Pro genotype seems to be an independent marker of poor prognosis (hazard ratio = 2.74; 95% confidence interval = 1.14–6.55, P = .014) together with clinical stage, MYCN status, and age at diagnosis. In vitro , p53-72P was less effective than p53-72R in inducing apoptosis and inhibiting survival of p53-null LAN-1 cells treated with etoposide, topotecan, or ionizing radiation but not taxol. By contrast, p53-72P was more effective in promoting p21-dependent accelerated senescence, alone or in the presence of etoposide. Thus, the p53-72 Pro/Pro genotype might be a marker of poor outcome independent of MYCN amplification, possibly improving risk stratification. Moreover, the lower apoptosis and the enhanced accelerated senescence by the p53-72P isoform in response to DNA damage suggest that patients with neuroblastoma with the p53-72 Pro/Pro genotype may benefit from therapeutic protocols that do not rely only on cytotoxic drugs that function, in part, through p53 activation.
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