Project description:Unluckily, FFPE archival methods lead to partial RNA degradation, limiting the amount of derivable information. This study aims to evaluate if the DASL gene expression assay, designed to generate reproducible data from degraded RNAs, is a reliable method to apply on RNA from FFPE tissues. In order to do that, we analyzed 20 FFPE breast cancer samples and 20 FF (Fresh Frozen) matched samples with the Illumina Whole Genome DASL platform for a genome-wide expression profiling.
Project description:Comparison between in vitro transcription- and cDNA-mediated annealing, selection and ligation (DASL)-based assays on brain-specific reference RNA, and postmortem frozen and formalin fixed brain tissue from autistic and control cases. Investigation of data preprocessing techniques for DASL-assayed RNA samples from frozen brain tissue.
Project description:Genome wide DNA methylation profiling of fresh frozen, histologically normal-appearing breast tissue from the Normal Breast Study (NBS). The Illumina HumanMethylation450 BeadChip was used to obtain DNA methylation profiles for 90 samples, including “current”, “former” and never users of HRT.
Project description:The Formalin-Fixed Paraffin-Embedded (FFPE) samples on selected breast cancer subtypes (ER+/Her2-, ER+/Her2+, ER-/Her2+, and ER-/Her2-) and their paired fresh fine needle aspirated biopsies (FNA) were investigated. The cases represented different subtypes of breast cancers based on their clinical receptors ER (E) and Her2 (H) status to demonstrate the ability of gene profiles to differentiate these tumors. Compared to FNA specimens, FFPE samples yielded relatively more degraded RNA, and 80% of the samples deemed suitable for cDNA-mediated annealing, selection, extension and ligation (DASL) assay. It is able to demonstrate that gene profiles from FFPE microarrays were reproducible and correlated well with the corresponding gene profiles from FNA microarrays. The gene profiles from both FNA and FFPE could differentiate the four breast cancer subtypes, and the expression levels of corresponding gene set were consistent with qRT-PCR and correlated to the clinical outcomes on published microarray data. It supports the use of FFPE specimens to develop a prognostic tool for breast cancers which can obviate the need for fresh specimens.
Project description:The Formalin-Fixed Paraffin-Embedded (FFPE) samples on selected breast cancer subtypes (ER+/Her2-, ER+/Her2+, ER-/Her2+, and ER-/Her2-) and their paired fresh fine needle aspirated biopsies (FNA) were investigated. The cases represented different subtypes of breast cancers based on their clinical receptors ER (E) and Her2 (H) status to demonstrate the ability of gene profiles to differentiate these tumors. Compared to FNA specimens, FFPE samples yielded relatively more degraded RNA, and 80% of the samples deemed suitable for cDNA-mediated annealing, selection, extension and ligation (DASL) assay. It is able to demonstrate that gene profiles from FFPE microarrays were reproducible and correlated well with the corresponding gene profiles from FNA microarrays. The gene profiles from both FNA and FFPE could differentiate the four breast cancer subtypes, and the expression levels of corresponding gene set were consistent with qRT-PCR and correlated to the clinical outcomes on published microarray data. It supports the use of FFPE specimens to develop a prognostic tool for breast cancers which can obviate the need for fresh specimens.
Project description:Tissue sample acquisition is a limiting step in many studies. There are many thousands of formalin fixed paraffin embedded archival blocks collected around the world, but in contrast relatively few fresh frozen samples in tumor banks. Once samples are fixed in formalin the RNA is degraded and traditional methods for gene expression profiling are not suitable. In this study we have evaluated the whole genome DASL assay from Illumina to perform transcriptomic analysis from archived breast tumor tissue fixed in formalin paraffin embedded blocks. We profiled 76 familial breast tumors from cases carrying a BRCA1, BRCA2 or ATM mutation, or from non-BRCA1/2 families. We found that replicate samples correlated well with each other (r2=0.9-0.98). In 12/15 cases, the matched formalin-fixed and frozen samples predicted the same tumor molecular subtypes with confidence. These results demonstrate that the whole genome DASL assay is a valuable tool to profile degraded RNA from archival FFPE material. This assay will enable transcriptomic analysis of a large number of archival samples that are stored in pathology archives around the globe and consequently will have the potential to improve our understanding and characterisation of many diseases.
Project description:The Formalin-Fixed Paraffin-Embedded (FFPE) samples on selected breast cancer subtypes (ER+/Her2-, ER+/Her2+, ER-/Her2+, and ER-/Her2-) and their paired fresh fine needle aspirated biopsies (FNA) were investigated. The cases represented different subtypes of breast cancers based on their clinical receptors ER (E) and Her2 (H) status to demonstrate the ability of gene profiles to differentiate these tumors. Compared to FNA specimens, FFPE samples yielded relatively more degraded RNA, and 80% of the samples deemed suitable for cDNA-mediated annealing, selection, extension and ligation (DASL) assay. It is able to demonstrate that gene profiles from FFPE microarrays were reproducible and correlated well with the corresponding gene profiles from FNA microarrays. The gene profiles from both FNA and FFPE could differentiate the four breast cancer subtypes, and the expression levels of corresponding gene set were consistent with qRT-PCR and correlated to the clinical outcomes on published microarray data. It supports the use of FFPE specimens to develop a prognostic tool for breast cancers which can obviate the need for fresh specimens. 25 FFPE specimens were processed for whole genome DASL assays using Illumina Human-Ref8 version 3 BeadChips. Invasive ductal carcinoma (IDC)-type subtypes ER+/Her2-, ER+/Her2+, ER-/Her2+, and ER-/Her2- (ER: estrogen receptor, HER2: human epidermal growth factor receptor 2) were analyzed.
Project description:Tissue sample acquisition is a limiting step in many studies. There are many thousands of formalin fixed paraffin embedded archival blocks collected around the world, but in contrast relatively few fresh frozen samples in tumor banks. Once samples are fixed in formalin the RNA is degraded and traditional methods for gene expression profiling are not suitable. In this study we have evaluated the whole genome DASL assay from Illumina to perform transcriptomic analysis from archived breast tumor tissue fixed in formalin paraffin embedded blocks. We profiled 76 familial breast tumors from cases carrying a BRCA1, BRCA2 or ATM mutation, or from non-BRCA1/2 families. We found that replicate samples correlated well with each other (r2=0.9-0.98). In 12/15 cases, the matched formalin-fixed and frozen samples predicted the same tumor molecular subtypes with confidence. These results demonstrate that the whole genome DASL assay is a valuable tool to profile degraded RNA from archival FFPE material. This assay will enable transcriptomic analysis of a large number of archival samples that are stored in pathology archives around the globe and consequently will have the potential to improve our understanding and characterisation of many diseases. RNA was extracted from FFPE Familial breast tumours and analysed using the WG-DASL assay for Illumina.