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27 result(s) for "Carreira, Christine"
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Prevalence of Papillomaviruses, Polyomaviruses, and Herpesviruses in Triple-Negative and Inflammatory Breast Tumors from Algeria Compared with Other Types of Breast Cancer Tumors
The possible role of viruses in breast cancer etiology remains an unresolved question. We hypothesized that if some viruses are involved, it may be in a subgroup of breast cancers only. Epidemiological arguments drove our interest in breast cancer subgroups that are more frequent in Africa, namely inflammatory breast cancer (IBC) and triple-negative breast cancer. We tested whether viral prevalence was significantly higher in these subgroups. One hundred fifty-five paraffin-embedded malignant breast tumors were randomly selected at the pathology laboratory of the University Hospital of Annaba (Algeria) to include one third of IBC and two thirds of non-IBC. They were tested for the presence of DNA from 61 viral agents (46 human papillomaviruses, 10 polyomaviruses, and 5 herpesviruses) using type-specific multiplex genotyping assays, which combine multiplex PCR and bead-based Luminex technology. Viral DNA was found in 22 (17.9%) of 123 tumors. The most prevalent viruses were EBV1 and HPV16. IBC tumors carried significantly more viruses (any type) than non-IBC tumors (30% vs. 13%, p<0.04). Similarly, triple-negative tumors displayed higher virus-positivity than non-triple-negative tumors (44% vs. 14%, p<0.009). Our results suggest an association between the presence of viral DNA and aggressive breast cancer phenotypes (IBC, triple-negative). While preliminary, they underline the importance of focusing on subgroups when studying viral etiology in breast cancer. Further studies on viruses in breast cancer should be conducted in much larger samples to confirm these initial findings.
Role of human papillomavirus infection in the etiology of vulvar cancer in Italian women
Background Vulvar squamous cell carcinoma (VSCC) is a rare malignancy of the female genital tract. We aimed to determine the mucosal high-risk human papillomavirus (HPV)-attributable fraction of VSCCs from Italian women using multiple markers of viral infections. Methods VSCCs and 8 metastatic lymph node samples from 107 Italian women were analyzed by a highly type-specific multiplex genotyping assay for the presence of DNA from 119 different HPVs. Tissues were further analyzed for HPV RNA and for upregulation of the cellular protein p16 INK4a . Results The rate of mucosal HPV-related tumors defined by viral DNA and RNA positivity was low (7.8%). HPV16 was the most prevalent, followed by 53, 56, and 58. Only five (4.9%) p16 INK4a -positive tumors were also positive for both viral DNA and RNA. One (14.3%) metastatic lymph node sample was positive for all three markers. DNA of cutaneous HPVs was detected in only two VSCCs, i.e. genus beta types 5 and 110. Conclusion A small proportion of Italian VSCCs is putatively HPV-related, i.e. positive for both viral DNA and RNA of the same type, thus reinforcing the importance of HPV vaccination. Moreover, this study suggests that a direct role of HPV from genus beta and gamma in vulvar carcinogenesis is unlikely.
Integrative Genome-Wide Gene Expression Profiling of Clear Cell Renal Cell Carcinoma in Czech Republic and in the United States
Gene expression microarray and next generation sequencing efforts on conventional, clear cell renal cell carcinoma (ccRCC) have been mostly performed in North American and Western European populations, while the highest incidence rates are found in Central/Eastern Europe. We conducted whole-genome expression profiling on 101 pairs of ccRCC tumours and adjacent non-tumour renal tissue from Czech patients recruited within the \"K2 Study\", using the Illumina HumanHT-12 v4 Expression BeadChips to explore the molecular variations underlying the biological and clinical heterogeneity of this cancer. Differential expression analysis identified 1650 significant probes (fold change ≥2 and false discovery rate <0.05) mapping to 630 up- and 720 down-regulated unique genes. We performed similar statistical analysis on the RNA sequencing data of 65 ccRCC cases from the Cancer Genome Atlas (TCGA) project and identified 60% (402) of the downregulated and 74% (469) of the upregulated genes found in the K2 series. The biological characterization of the significantly deregulated genes demonstrated involvement of downregulated genes in metabolic and catabolic processes, excretion, oxidation reduction, ion transport and response to chemical stimulus, while simultaneously upregulated genes were associated with immune and inflammatory responses, response to hypoxia, stress, wounding, vasculature development and cell activation. Furthermore, genome-wide DNA methylation analysis of 317 TCGA ccRCC/adjacent non-tumour renal tissue pairs indicated that deregulation of approximately 7% of genes could be explained by epigenetic changes. Finally, survival analysis conducted on 89 K2 and 464 TCGA cases identified 8 genes associated with differential prognostic outcomes. In conclusion, a large proportion of ccRCC molecular characteristics were common to the two populations and several may have clinical implications when validated further through large clinical cohorts.
Human papillomavirus type 16 antagonizes IRF6 regulation of IL-1β
Human papillomavirus type 16 (HPV16) and other oncoviruses have been shown to block innate immune responses and to persist in the host. However, to avoid viral persistence, the immune response attempts to clear the infection. IL-1β is a powerful cytokine produced when viral motifs are sensed by innate receptors that are members of the inflammasome family. Whether oncoviruses such as HPV16 can activate the inflammasome pathway remains unknown. Here, we show that infection of human keratinocytes with HPV16 induced the secretion of IL-1β. Yet, upon expression of the viral early genes, IL-1β transcription was blocked. We went on to show that expression of the viral oncoprotein E6 in human keratinocytes inhibited IRF6 transcription which we revealed regulated IL-1β promoter activity. Preventing E6 expression using siRNA, or using E6 mutants that prevented degradation of p53, showed that p53 regulated IRF6 transcription. HPV16 abrogation of p53 binding to the IRF6 promoter was shown by ChIP in tissues from patients with cervical cancer. Thus E6 inhibition of IRF6 is an escape strategy used by HPV16 to block the production IL-1β. Our findings reveal a struggle between oncoviral persistence and host immunity; which is centered on IL-1β regulation.
Role of mucosal high-risk human papillomavirus types in head and neck cancers in Romania
Limited information is available about the involvement of human papillomavirus (HPV) in head and neck squamous cell carcinomas (HNSCCs) in Romanian patients. To evaluate the HPV-attributable fraction in HNSCCs collected in Northeastern Romania. In total, 189 formalin-fixed paraffin-embedded tissue samples (99 oral cavity tumors, 28 oropharynx, 48 pharynx, and 14 larynx/hypopharynx) were analyzed for HPV DNA and RNA using Luminex-based assays, and for overexpression of p16INK4a (p16) by immunohistochemistry. Of the 189 cases, 23 (12.2%) were HPV DNA-positive, comprising half of the oropharyngeal cases (14/28, 50.0%) and 9/161 (5.6%) of the non-oropharyngeal cases. HPV16 was the most prevalent HPV type (20/23, 86.9%), followed by HPV18 (5/23, 21.7%) and HPV39 (1/23, 4.3%). Only two (2/189, 1.1%) HNSCC cases were HPV-driven, i.e. positive for both HPV DNA and RNA. A very small subset of HNSCC cases within this cohort from Northeastern Romania appeared to be HPV-driven.
Characterisation of prostate cancer lesions in heterozygous Men1 mutant mice
Background Mutations of the MEN1 gene predispose to multiple endocrine neoplasia type 1 (MEN1) syndrome. Our group and others have shown that Men1 disruption in mice recapitulates MEN1 pathology. Intriguingly, rare lesions in hormone-dependent tissues, such as prostate and mammary glands, were also observed in the Men1 mutant mice. Methods To study the occurrence of prostate lesions, we followed a male mouse cohort of 47 Men1 +/- mice and 23 age-matched control littermates, starting at 18 months of age, and analysed the prostate glands from the cohort. Results Six Men1 +/- mice (12.8%) developed prostate cancer, including two adenocarcinomas and four in situ carcinomas, while none of the control mice developed cancerous lesions. The expression of menin encoded by the Men1 gene was found to be drastically reduced in all carcinomas, and partial LOH of the wild-type Men1 allele was detected in three of the five analysed lesions. Using immunostaining for the androgen receptor and p63, a basal epithelial cell marker, we demonstrated that the menin-negative prostate cancer cells did not display p63 expression and that the androgen receptor was expressed but more heterogeneous in these lesions. Furthermore, our data showed that the expression of the cyclin-dependent kinase inhibitor CDKN1B (p27), a Men1 target gene known to be inactivated during prostate cell tumorigenesis, was notably decreased in the prostate cancers that developed in the mutant mice. Conclusion Our work suggests the possible involvement of Men1 inactivation in the tumorigenesis of the prostate gland.
A protocol for good quality genomic DNA isolation from formalin-fixed paraffin-embedded tissues without using commercial kits
Background DNA isolation from formalin-fixed paraffin-embedded (FFPE) tissues for molecular analysis has become a frequent procedure in cancer research. However, the yield or quality of the isolated DNA is often compromised, and commercial kits are used to overcome this to some extent. Methods We developed a new protocol (IARCp) to improve the quality and yield of DNA from FFPE tissues without using any commercial kit. To evaluate the IARCp’s performance, we compared the quality and yield of DNA with two commercial kits, namely NucleoSpin® DNA FFPE XS (MN) and QIAamp DNA Micro (QG) isolation kit. Results Total DNA yield for QG ranged from 120.0 to 282.0 ng (mean 216.5 ng), for MN: 213.6–394.2 ng (mean 319.1 ng), and with IARCp the yield was much higher ranging from 775.5 to 1896.9 ng (mean 1517.8 ng). Moreover, IARCp has also performed well in qualitative assessments by spectrophotometer, fluorometer, and real-time PCR assay. Conclusion Overall, IARCp represents a novel approach to DNA isolation from FFPE which results in good quality and significant amounts of DNA suitable for many downstream genome-wide and targeted molecular analyses. This protocol does not require the use of any commercial kits or phenol for isolating DNA from FFPE tissues, making it suitable to implement in low-resource settings such as low and middle-income countries.
Variation in genomic landscape of clear cell renal cell carcinoma across Europe
The incidence of renal cell carcinoma (RCC) is increasing worldwide, and its prevalence is particularly high in some parts of Central Europe. Here we undertake whole-genome and transcriptome sequencing of clear cell RCC (ccRCC), the most common form of the disease, in patients from four different European countries with contrasting disease incidence to explore the underlying genomic architecture of RCC. Our findings support previous reports on frequent aberrations in the epigenetic machinery and PI3K/mTOR signalling, and uncover novel pathways and genes affected by recurrent mutations and abnormal transcriptome patterns including focal adhesion, components of extracellular matrix (ECM) and genes encoding FAT cadherins. Furthermore, a large majority of patients from Romania have an unexpected high frequency of A:T>T:A transversions, consistent with exposure to aristolochic acid (AA). These results show that the processes underlying ccRCC tumorigenesis may vary in different populations and suggest that AA may be an important ccRCC carcinogen in Romania, a finding with major public health implications. Renal cancer accounts for 2.4% of all adult cancers and its incidence is increasing worldwide. Here, the authors carry out genome and transcriptome sequencing of clear cell renal cell carcinomas (ccRCCs) and highlight genomic aberrations and biological pathways underlying ccRCC tumorigenesis.