Project description:Oncogenic human papillomavirus (HPV) genomes are often integrated into host chromosomes in HPV-associated cancers. HPV genomes are integrated either as a single copy, or as tandem repeats of viral DNA interspersed with, or without, host DNA. Integration occurs frequently in common fragile sites susceptible to tandem repeat formation, and the flanking or interspersed host DNA often contains transcriptional enhancer elements. When co-amplified with the viral genome, these enhancers can form super-enhancer-like elements that drive high viral oncogene expression. Here, we compiled highly curated datasets of HPV integration sites in cervical (CESC) and head and neck squamous cell carcinoma (HNSCC) cancers and assessed the number of breakpoints, viral transcriptional activity, and host genome copy number at each insertion site. Tumors frequently contained multiple distinct HPV integration sites, but often only one “driver” site that expressed viral RNA. Since common fragile sites and active enhancer elements are cell-type specific, we mapped these regions in cervical cell lines using FANCD2 and Brd4/H3K27ac ChIP-seq, respectively. Large enhancer clusters, or super-enhancers, were also defined using the Brd4/H3K27ac ChIP-seq dataset. HPV integration breakpoints were enriched at both FANCD2-associated fragile sites, and enhancer-rich regions, and frequently showed adjacent focal DNA amplification in CESC samples. We identified recurrent integration “hotspots” that were enriched for super-enhancers, some of which function as regulatory hubs for cell-identity genes. We propose that during persistent infection, extrachromosomal HPV minichromosomes associate with these transcriptional epicenters, and accidental integration could promote viral oncogene expression and carcinogenesis.
Project description:Multiple HPV genotypes infection is frequently detected in HPV+ cervical lesions, however it is not well stablished how is the different viral interaction during the carcinogenic process. Here we carried out a comprehensive study to characterize the multiple HPV genome expression and integration by RNA-Seq analysis in 19 invasive cervical carcinomas with HPV coinfections. Analysis of tumoral DNA by a hybridization kit indicated multi-infection ranging from 2 to 6 different HPV genotypes, without a preferential species coinfection. The expression analysis showed that a single HPV genotype preferentially expressed its genome, might indicating a competition between the infecting virus. Finally, the search for HPV/human chimeric transcripts indicated integration from just one HPV in almost all samples, corroborating the expression findings.
Project description:Integration of human papillomavirus (HPV) DNA into the host genome is a critical aetiological event in the progression from normal cervix to intraepithelial neoplasm, and finally to invasive cervical cancer. In this study, we want to know how HPV DNA physical status relates to treatment outcome for cervical carcinomas. Cervical cancer samples were compared with normal sample. And also, we divided 39 cervical cancer patients into four groups according to HPV DNA physical status and investigated differentially expressed gene profiles in these groups using Agilent two-color experiment.
Project description:Integration of human papillomavirus (HPV) DNA into the host genome is a critical aetiological event in the progression from normal cervix to intraepithelial neoplasm, and finally to invasive cervical cancer. In this study, we want to know how HPV DNA physical status relates to treatment outcome for cervical carcinomas.
Project description:<p>Cervical cancer is responsible for 10-15% of cancer related deaths in women worldwide. The etiological role of infection with high-risk human papilloma viruses (HPV) in carcinomas of the cervix is well established. In general, the development of cervical carcinomas follows a progression from persistent HPV infection through precancerous lesions to invasive cancer. Previous studies have implicated somatic mutations in PIK3CA, PTEN, TP53, STK11 and KRAS as well as chromosome-arm level copy number alterations in the pathogenesis of cervical carcinomas. Here, we report whole exome sequencing analysis of 118 cervical carcinoma-normal paired samples from patients in Norway and Mexico, as well as transcriptome sequencing of 80 cases and whole genome sequencing of 13 tumor-normal pairs. Novel somatic mutations include recurrent E322K substitutions in the MAPK1 gene encoding the ERK2 kinase and inactivating mutations in the HLA-B gene. In addition, recurrent somatic mutations in FBXW7, EP300, and NFE2L2 are novel in the context of primary cervical carcinomas. Analysis of HPV integration sites revealed recurrent integration into the RAD51B locus as well as co-occurrence of HPV genome integration and copy number gains within several genomic loci. These findings shed new light on the pathogenesis of cervical carcinomas and suggest potential novel therapeutic targets.</p>
Project description:In most cases human papillomavirus (HPV) infections are cleared from the cervical cells by the immune system itself, but in a few cases, where there is persistent HPV infection, it can lead to cervical intraepithelial neoplasia (CIN) progression and ultimately invasive cervical carcinoma. The cytopathic effect is in general accompanied by chronic inflammation, which produces inflammation cytokines that contribute to DNA damage, and at the same time, aberrations occurred in the host DNA repair mechanisms, thus lead to HPV genomic integration into the host cells which propels cell immortalization. In this study, we reported the genome-wide expression profiles of both microRNAs (miRNAs) and mRNAs from 24 cervical samples with consecutive stages of normal, CIN I (mild dysplasia) and CIN III (severe dysplasia and carcinoma in situ), and presented the SIG++ algorithm which is founded on the evolution process of intermolecular regulation change during disease progression, to identify the significant change of miRNA-mRNA regulations rather than the expression change, across different disease stages, thereupon elucidating the molecular mechanisms of increasing host genomic instability as disease progresses. As reconstructing miRNA differential networks, we found that at each stage of CIN, there respectively exists specific miRNA regulations mediating chronic inflammation persistence, genome instability and cell survival, which coordinately carrys out the integration of HPV genomes into the host cell genomes, and finally results in cell immortalization. Beyond the specific implications for cervical carcinogenesis, this work establishes a new framework for studying the biology of miRNAs in pathogenesis from the perspective of miRNA differential regulation, and helps ensure the comprehensiveness of miRNA-mediated genetic regulatory pathways. There are totally 24 clinical samples in this study comprises three stages: 7 normal cervix samples (HPV-), 9 CIN I samples (HPV+) and CIN III samples (HPV+), where normal refers to the adjacent tissue of early lesions. For each sample, its total RNA was extracted and purified, then separately hybridized to Illumina HumanHT-12 V4.0 expression beadchip (gene symbol) and Illumina Human v2 MicroRNA Expression BeadChip, for examining the expression profiles of mRNAs and miRNAs, respectively.
Project description:Human papillomavirus (HPV) genome integration into the host genome, blocking E2 expression and leading to overexpression of E6 and E7 viral oncogenes, is considered a major step in cervical cancer development. In high-risk HPVs, E6 and E7 oncogenes are expressed as a bicistronic pre-mRNA, with alternative splicing producing the ultimate mRNAs required for E6 and E7 translation. Given the number of alternative donor and acceptor splicing sites, ten E6/E7 different alternative transcripts might be formed for HPV16 and three for HPV18, although only six isoforms have been previously reported for HPV16. In the present work, we employ high-throughput sequencing of invasive cervical cancer transcriptome (RNA-Seq) to characterize the expression of the HPV genome in 24 invasive cervical cancers associated with HPV16 and HPV18 single infections. Based on high-resolution transcriptional maps, we herein report three viral gene expression patterns which might be associated with the presence of the viral genome in episomal and/or integrated stages. Alternative mRNAs splicing isoforms coding for E6 and E7 oncoproteins were characterized and quantified, and two novel isoforms were identified. Three major isoforms (E6*I, E6*II, and E6+E7) were detected for HPV16 and two for HPV18 (E6*I and E6+E7). Minor transcript isoforms, including the novel ones, were very rare in some tumor samples or were not detected. Our data suggested that minor transcript isoforms of E6/E7 do not play a relevant role in cervical cancer.
Project description:Human papillomaviruses (HPV) preferentially infect keratinocytes of mucous membranes or skin and cause numerous benign and malignant lesions at different anatomical locations. We sequenced small RNA (sRNA) libraries of two HPV 16 immortalized cell lines and ten formalin fixed paraffin embedded (FFPE) tissue samples from HPV infected cervical epithelium by SOLiD 4 technology.
Project description:Human papillomavirus (HPV) is the etiological agent of cervical cancer. Three viral proteins, E5, E6 and E7 have been implicated in cell transformation. Increased expression of sialic acid and sialylated antigens have been reported during cervix transformation, these results agree with the increased mRNA levels of the sialyltransferases genes ST6GAL1 and ST3GAL3 reported in premalignant and malignant tissue of the cervix. E6 and E7 HPV oncoproteins modify the expression of some glycogenes. The role of E5 HPV oncoprotein in the glycogene expression changes in premalignant and malignant cervical tissue has not been reported. The objective of this work was to identify glycogenes that modify their expression by E5 HPV oncoprotein in HaCaT cell line. A gene expression microarray was performed on HaCaT cells that stably expressed the HPV16 E5 oncogene. Analysis revealed alteration in some glycogenes including upregulation of ST6GAL1 and ST3GAL3. The increased mRNA levels of both genes were confirmed by qRT-PCR. In addition, an in-silico analysis was performed to identify glycosylation networks altered in presence of E5 oncoprotein. The analysis showed that E5 could modify the sialic acid expression, keratan sulfate synthesis, N-glycosylation and biosynthesis of glycosaminoglycans. This is the first report of the role of HPV16 E5 oncoprotein on glycogenes expression changes. Moreover, our results suggest that the increase of the sialyltransferases genes reported in premalignant and malignant cervical tissue, could be the result of the expression of E5 oncoprotein. These results provide information of the possible role of HPV infection on the sialylation changes in the cervical epithelium identified in premalignant lesions and cancer.
Project description:Cervical cancer ranks as the first in cancer mortality among women of low-middle income countries, where 80% of the 570,000 cases and 311,000 worldwide deaths estimated for 2018 occurred (Ferlay et al. 2018 ). Persistent infections with high-risk HPV (hrHPV) genotypes can lead to high-grade cervical intraepithelial (CIN) grade 2 (CIN2) or higher, (CIN2+), if untreated, a high percentage of these lesions may progress to cancer. Despite its high sensitivity, the hrHPV test has low specificity to detect CIN2+ lesions given that a high percentage of women (80 %) infected with hrHPV genotypes will resolve the infection spontaneously. microRNAs (miRNAs) are small non-coding RNAs and their differential expression patterns seen to be associated with cervical intraepithelial lesions. Our work aimed to identify miRNAs differentially expressed in CIN2+ respect with <CIN1 and to evaluate their potential use as biomarkers to distinguish low- from high-grade lesions within hrHPV positive women. For our discovery set we used small RNA sequencing (miRNA-seq) to compare the miRNA expression patterns in 20 Formalin-Fixed Paraffin-Embedded (FFPE) tissues from hrHPV-positive women from Medellin, Colombia presenting low- (n=10) and high-grade lesions (n=10). Top five miRNAs presenting high fold change and low coefficient of variation were used validated by RT-PCR in our validation set composed 210 age-matched independent hrHPV-positive FFPE tissues, and an in-silico approach was used to understand the function of the differentially expressed miRNAs in the context of HPV infection.