Project description:Cervical cancer results from the accumulation of (epi)genetic aberrations following persistent infection with high-risk human papillomavirus (HPV). In order to define genetic aberrations associated with cervical carcinogenesis, chromosomal profiles of high-grade cervical intraepithelial neoplasia (CIN) were generated. Common aberrations usually encompass large genomic regions and contain numerous genes, hampering identification of actual driver genes. Consequently, direct evidence of chromosomal alterations actively contributing to cervical carcinogenesis has been lacking so far. By analyzing 60 high-grade CIN with high resolution arrayCGH we identified focal chromosomal aberrations that each harbour only one or a few genes. In total 74 focal aberrations were identified encoding 305 genes. Analysis of genes located within these focal aberrations, using two independent expression microarray datasets, revealed concurrent altered expression in high-grade CIN and/or cervical carcinomas compared to normal cervical samples for 8 genes: ATP13A3, HES1, OPA1, HRASLS, EYA2, ZMYND8, APOBEC2 and NCR2. Gene silencing of EYA2, located within a focal gain at 20q13, significantly reduced viability and migratory capacity of HPV16-transformed keratinocytes. Interestingly, for hsa-miR-375, located within the most frequently identified focal loss at 2q35, a direct correlation between a (focal) loss and significantly reduced expression was found. Down-regulation of hsa-miR-375 expression during cervical carcinogenesis was confirmed in a second independent series of cervical tissues. Moreover, ectopic expression of hsa-miR-375 in 2 cervical carcinoma cell lines reduced cellular viability. In conclusion, our data provide a proof of concept that chromosomal aberrations are actively contributing to HPV-induced carcinogenesis and identify EYA2 and hsa-mir-375 as oncogene and tumor suppressor gene, respectively. DNA from microdissected tissues: 60 samples total. 11 high-grade CIN, <5yr preceding hrHPV infection, 43 high-grade CIN >5yr preceding hrHPV infection, 6 CIN3 adjacent to SCC

Project description:Little is known about the alterations in microRNA (miRNA) expression patterns during the consecutive stages of cervical cancer development and their association with chromosomal instability and epigenetic changes. We integrated miRNA expression profiles in normal cervical squamous epithelium, high-grade precancerous lesions (CIN2-3), squamous cell carcinomas (SCC) and adenocarcinomas (AdCAs) with previously generated chromosomal profiles of the same samples. In addition, the DNA methylation status of downregulated miRNAs located in a CpG island was determined. Significantly differential expression during the consecutive stages of cervical SCC development was observed for 106 miRNAs. Altered expression of 5 significantly differentially expressed miRNAs, hsa-miR-9 (1q23.2), hsa-miR-15b (3q25.32), hsa-miR-28-5p (3q27.3), hsa-miR-100 and hsa-miR-125b (both 11q24.1) was directly linked to frequent chromosomal alterations. Another 9 significantly downregulated miRNAs were located within a CpG island. Three of these 9 miRNAs, hsa-miR-203, hsa-miR-572, and hsa-miR-638, showed increased methylation in cervical cancer cell lines and HPV-immortalised cells compared to primary keratinocytes. Functional analyses were performed for hsa-miR-9, representing a potential oncogene with increased expression linked to a chromosomal gain, and hsa-miR-203, representing a potential tumour suppressor gene silenced by DNA methylation. Hsa-miR-9 and hsa-miR-203 were found to alter cell viability and anchorage independent growth in vitro, respectively, supporting their oncogenic and tumour suppressive function in cervical cancer. In conclusion, differential expression of 106 miRNAs, partly associated with chromosomal alterations and epigenetic changes, was observed during cervical SCC development. Altered expression of hsa-miR-9 and hsa-miR-203 was shown to be functionally relevant, underlining the importance of deregulated miRNA expression in cervical carcinogenesis. 10 squamous cell carcinomas of the cervix, 9 adenocarcinomas of the cervix, 18 high-grade cervical intraepithelial neoplasias (CIN2-3), and 10 cervical squamous epithelial samples with normal histology were analysed using single channel (Cy3) miRNA microarrays from Agilent (G4471A-016436).

Project description:Invasive lobular carcinoma (ILC) of the breast accounts for 5-15% of breast cancers and is characterized by loss of E-cadherin and believed to arise via a linear histological progression. Genomic studies have identified a clonal relationship between ILC and concurrent lobular carcinoma in situ (LCIS) lesions, suggesting that LCIS may be a precursor lesion. It has been shown that an LCIS diagnosis confers a 15-20% risk of progression to ILC, over a lifetime. Currently no molecular test or markers can identify LCIS lesions likely to progress to ILC. Since microRNA (miRNA) expression changes have been detected in a number of other cancer types, we explored whether their dysregulation might be detected during progression from LCIS to ILC. Using the Illumina miRNA profiling platform, designed for simultaneous analysis of 470 mature miRNAs, we analyzed the profiles of archived normal breast epithelium, LCIS lesions found alone, LCIS lesions concurrent with ILC, and the concurrent ILCs, as a model of linear histological progression toward ILC. We identified two sets of differentially expressed miRNAs, the first set highly expressed in normal epithelium, including hsa-miR-224, -139, -10b, -450, 140 and -365 and the second set upregulated during lobular neoplasia, including hsa-miR-375, -203, -425-5p, -183, -565 and -182. Using quantitative RT-PCR, we validated a trend of increased expression for hsa-mir-375, hsa-mir-182, and hsa-mir-183 correlating with ILC progression. As we detected increased expression of hsa-miR-375 in LCIS lesions synchronous with ILC, we sought to determine whether hsa-mir-375 might induce phenotypes reminiscent of lobular neoplasia by expressing it in the MCF10A 3D culture model of mammary acinar morphogenesis. Increased expression of hsa-miR-375 resulted in loss of cellular organization and acquisition of a hyperplastic phenotype. These data suggest that dysregulated miRNA expression contributes to lobular neoplastic progression.

Project description:Invasive lobular carcinoma (ILC) of the breast accounts for 5-15% of breast cancers and is characterized by loss of E-cadherin and believed to arise via a linear histological progression. Genomic studies have identified a clonal relationship between ILC and concurrent lobular carcinoma in situ (LCIS) lesions, suggesting that LCIS may be a precursor lesion. It has been shown that an LCIS diagnosis confers a 15-20% risk of progression to ILC, over a lifetime. Currently no molecular test or markers can identify LCIS lesions likely to progress to ILC. Since microRNA (miRNA) expression changes have been detected in a number of other cancer types, we explored whether their dysregulation might be detected during progression from LCIS to ILC. Using the Illumina miRNA profiling platform, designed for simultaneous analysis of 470 mature miRNAs, we analyzed the profiles of archived normal breast epithelium, LCIS lesions found alone, LCIS lesions concurrent with ILC, and the concurrent ILCs, as a model of linear histological progression toward ILC. We identified two sets of differentially expressed miRNAs, the first set highly expressed in normal epithelium, including hsa-miR-224, -139, -10b, -450, 140 and -365 and the second set upregulated during lobular neoplasia, including hsa-miR-375, -203, -425-5p, -183, -565 and -182. Using quantitative RT-PCR, we validated a trend of increased expression for hsa-mir-375, hsa-mir-182, and hsa-mir-183 correlating with ILC progression. As we detected increased expression of hsa-miR-375 in LCIS lesions synchronous with ILC, we sought to determine whether hsa-mir-375 might induce phenotypes reminiscent of lobular neoplasia by expressing it in the MCF10A 3D culture model of mammary acinar morphogenesis. Increased expression of hsa-miR-375 resulted in loss of cellular organization and acquisition of a hyperplastic phenotype. These data suggest that dysregulated miRNA expression contributes to lobular neoplastic progression. 6 specimens were analyzed in duplicate. One frozen normal lobular epithelium and the matched FFPE (1 month old) normal lobular epithelium. One lobular carcinoma in situ (LCIS) found alone, one LCIS synchronous with an invasive lobular carcinoma (ILC), the synchronous ILC (from a different archived block), and one ILC found alone without presence of any other breast cancer.

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.

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Focal chromosomal aberrations in high-grade cervical intraepithelial neoplasia reveal hsa-miR-375 and EYA2 as drivers in HPV-mediated transformation

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