Project description:Degradation and chemical modification of RNA in formalin-fixed paraffin-embedded (FFPE) samples hamper their use in expression profiling studies. In this study, we investigated the feasibility of gene expression signature generation from archival FFPE materials. Nineteen cervical squamous cell carcinoma (SCC) and nine adenocarcinoma (AC) 10~16-year-old FFPE samples were profiled using Affymetrix Exon 1.0 ST arrays. A comparison of the global gene expression changes between SCC and AC revealed 1217 differentially expressed genes. Of these, 1062 showed significantly higher expression levels in SCC relative to AC, and 155 genes were found to be specifically upregulated in AC. When the 1217-gene signature was tested on a fresh-frozen human non-small cell lung cancer (NSCLC) series, it correctly separated the 58 NSCLC samples into SCC and AC. In conclusion, our results showed that clinically and biologically relevant gene expression profiles can be derived from FFPE samples with Exon array profiling.
Project description:Degradation and chemical modification of RNA in formalin-fixed paraffin-embedded (FFPE) samples hamper their use in expression profiling studies. In this study, we investigated the feasibility of gene expression signature generation from archival FFPE materials. Nineteen cervical squamous cell carcinoma (SCC) and nine adenocarcinoma (AC) 10~16-year-old FFPE samples were profiled using Affymetrix Exon 1.0 ST arrays. A comparison of the global gene expression changes between SCC and AC revealed 1217 differentially expressed genes. Of these, 1062 showed significantly higher expression levels in SCC relative to AC, and 155 genes were found to be specifically upregulated in AC. When the 1217-gene signature was tested on a fresh-frozen human non-small cell lung cancer (NSCLC) series, it correctly separated the 58 NSCLC samples into SCC and AC. In conclusion, our results showed that clinically and biologically relevant gene expression profiles can be derived from FFPE samples with Exon array profiling. The study population contains 28 FFPE human cervix samples (19 SCC and 9 AC). Histopathology assessment and p63 IHC were performed on all samples to confirm their histological subtypes. Total RNA was extracted and hybridised to Affymetrix Human Exon 1.0 ST arrays. Expression values were normalised using RMA. Only exonic probesets that were flagged as present (DABG< 0.01) in at least three samples were retained for further analysis. LIMMA was used to identify probesets that were differentially expressed between SCC and AC subtypes, using FDR ≤ 0.01 and absolute fold-change ≥ 2 as cutoff.
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples 18 samples hybridised to miRNA microarray V2 arrays, 2 cervix cell lines and 16 clinical cervical tumour samples. There are no technical replicates.
Project description:To contrastively analyze the expression pattern of circRNAs in cervical squamous carcinoma, adenocarcinoma and adenosquamous carcinoma variants. CircRNAs expression in cervical squamous carcinoma, adenocarcinoma and adenosquamous carcinoma tissues together with the adjacent normal tissues were profiled by high-throughput RNA sequencing.
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples
Project description:Background: As degradation of formalin-fixed paraffin-embedded (FFPE) samples limits ability to expression profile, we explored factors predicting success for FFPE profiling and investigated an approach overcoming this limitation. Methods: Bladder (n=141, stored 3-8 years) and cervix (n=160, stored 8-23 years) carcinoma FFPE samples were hybridised to Affymetrix Exon1.0ST arrays. Percent detection above background (%DABG) measured technical success. Biological signal was assessed by distinguishing cervix squamous cell carcinoma (SCC) and adenocarcinoma (AC) using a gene signature. Precursor mir-205 was measured by Exon array and mature miR-205 by qRT-PCR. Eight-old and -young cervix samples were compared using Affymetrix miRNA 2.0 arrays. For comparison, the 'cervix_tumour_cs1_113' (previsously submitted GSM677307) was included and re-analyzed with the samples from the current study (total 161 Cervix samples). Results: RNA quality controls (e.g. RNA integrity number) failed to predict profiling success, but sample age correlated with %DABG in bladder (R2=-0.30, p<0.01) and cervix (R2=-0.69, p<0.01). Biological signal was lost in older samples and neither a signature nor precursor mir-205 separated samples by histology. miR-205 qRT-PCR discriminated SCC from AC, validated by miRNA profiling (26-fold higher in SCC; p=1.10x10-5). Median miRNA probeset expression of eight-old and eight-young cervix samples correlated well (R2=0.95) overcoming the age-related bias of mRNA probesets, suggesting miR-205 stability generalises across microRNA. Conclusions: microRNA profiling overcomes the limitation of degraded FFPE samples 113 Cervix tumour FFPE samples hybridized to exon arrays