Project description:About 50% of resected pancreatic ductal adenocarcinoma (PDAC) recur within just one year following surgery. Prognostic molecular markers predicting rapid recurrence are currently unavailable. We hypothesized that epigenetic differences at the level of chromatin accessibility, potentially linked to distinct differentiation states, might distinguish rapidly recurrent from non-recurrent tumors. Therefore, we interrogated genome-wide chromatin accessibility using Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) on EpCAM+ PDAC malignant cells sorted from a cohort of 54 treatment-naïve resected tumors, in hopes of defining a tumor-intrinsic chromatin signature associated with recurrence. We discovered a signature of ~1000 loci that were differentially accessible between recurrent (disease free survival (DFS) < 1 year) and non-recurrent patients (DFS > 1 year). Through transcription factor (TF) binding motif analysis using supervised learning, we identified candidate TFs whose accessible motifs were differentially associated with recurrence. Nuclear localization of two such TFs as selected by top hits, ZKSCAN1 and HNF1b, were assessed by both immunohistochemistry and immunofluorescence on the tissue microarrays (TMA) of 40 out of 54 patients. Nuclear staining of HNF1b was strong in the non-recurrent and weak or absent in the recurrent patients but ZKSCAN1 was not significantly associated with recurrence. In an independent TMA of PDAC cohort (n=97) preselected for 52 long (OS 6 years)- and 45 short (OS 6 months)- term survivors, the number of nuclear positive cells for HNF1b was 52-fold higher in the long-term compared to the short-term survivors and that for ZKSCAN1 was 5.3-fold higher in the short-term compared to the long-term survivors. Altogether, these results provide novel prognostic molecular markers of early recurrence in PDAC and also suggest that the global epigenetic landscape is a prognostic feature in this disease.
Project description:About 50% of resected pancreatic ductal adenocarcinoma (PDAC) recur within just one year following surgery. Prognostic molecular markers predicting rapid recurrence are currently unavailable. We hypothesized that epigenetic differences at the level of chromatin accessibility, potentially linked to distinct differentiation states, might distinguish rapidly recurrent from non-recurrent tumors. Therefore, we interrogated genome-wide chromatin accessibility using Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) on EpCAM+ PDAC malignant cells sorted from a cohort of 54 treatment-naïve resected tumors, in hopes of defining a tumor-intrinsic chromatin signature associated with recurrence. We discovered a signature of ~1000 loci that were differentially accessible between recurrent (disease free survival (DFS) < 1 year) and non-recurrent patients (DFS > 1 year). Through transcription factor (TF) binding motif analysis using supervised learning, we identified candidate TFs whose accessible motifs were differentially associated with recurrence. Nuclear localization of two such TFs as selected by top hits, ZKSCAN1 and HNF1b, were assessed by both immunohistochemistry and immunofluorescence on the tissue microarrays (TMA) of 40 out of 54 patients. Nuclear staining of HNF1b was strong in the non-recurrent and weak or absent in the recurrent patients but ZKSCAN1 was not significantly associated with recurrence. In an independent TMA of PDAC cohort (n=97) preselected for 52 long (OS 6 years)- and 45 short (OS 6 months)- term survivors, the number of nuclear positive cells for HNF1b was 52-fold higher in the long-term compared to the short-term survivors and that for ZKSCAN1 was 5.3-fold higher in the short-term compared to the long-term survivors. Altogether, these results provide novel prognostic molecular markers of early recurrence in PDAC and also suggest that the global epigenetic landscape is a prognostic feature in this disease.
Project description:About 50% of resected pancreatic ductal adenocarcinoma (PDAC) recur within just one year following surgery. Prognostic molecular markers predicting rapid recurrence are currently unavailable. We hypothesized that epigenetic differences at the level of chromatin accessibility, potentially linked to distinct differentiation states, might distinguish rapidly recurrent from non-recurrent tumors. Therefore, we interrogated genome-wide chromatin accessibility using Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) on EpCAM+ PDAC malignant cells sorted from a cohort of 54 treatment-naïve resected tumors, in hopes of defining a tumor-intrinsic chromatin signature associated with recurrence. We discovered a signature of ~1000 loci that were differentially accessible between recurrent (disease free survival (DFS) < 1 year) and non-recurrent patients (DFS > 1 year). Through transcription factor (TF) binding motif analysis using supervised learning, we identified candidate TFs whose accessible motifs were differentially associated with recurrence. Nuclear localization of two such TFs as selected by top hits, ZKSCAN1 and HNF1b, were assessed by both immunohistochemistry and immunofluorescence on the tissue microarrays (TMA) of 40 out of 54 patients. Nuclear staining of HNF1b was strong in the non-recurrent and weak or absent in the recurrent patients but ZKSCAN1 was not significantly associated with recurrence. In an independent TMA of PDAC cohort (n=97) preselected for 52 long (OS 6 years)- and 45 short (OS 6 months)- term survivors, the number of nuclear positive cells for HNF1b was 52-fold higher in the long-term compared to the short-term survivors and that for ZKSCAN1 was 5.3-fold higher in the short-term compared to the long-term survivors. Altogether, these results provide novel prognostic molecular markers of early recurrence in PDAC and also suggest that the global epigenetic landscape is a prognostic feature in this disease.
Project description:Unlike other malignancies, therapeutic options in pancreatic ductal adenocarcinoma (PDAC) are largely limited to cytotoxic chemotherapy without the benefit of molecular markers predicting response. Here we report tumor-cell-intrinsic chromatin accessibility patterns of treatment-naïve surgically resected PDAC tumors that were subsequently treated with (Gem)/Abraxane adjuvant chemotherapy. By ATAC-seq analyses of EpCAM+ PDAC malignant epithelial cells sorted from 54 freshly resected human tumors, we show here the discovery of a signature of 1092 chromatin loci displaying differential accessibility between patients with disease free survival (DFS) < 1 year and patients with DFS > 1 year. Analyzing transcription factor (TF) binding motifs within these loci, we identify two TFs (ZKSCAN1 and HNF1b) displaying differential nuclear localization between patients with short vs. long DFS. We further develop a chromatin accessibility microarray methodology termed "ATAC-array", an easy-to-use platform obviating the time and cost of next generation sequencing. Applying this methodology to the original ATAC-seq libraries as well as independent libraries generated from patient-derived organoids, we validate ATAC-array technology in both the original ATAC-seq cohort as well as in an independent validation cohort. We conclude that PDAC prognosis can be predicted by ATAC-array, which represents a low-cost, clinically feasible technology for assessing chromatin accessibility profiles.
Project description:Chromatin accessibility plays an essential role in controlling cellular identity and the therapeutic response of human cancers. However, the chromatin accessibility landscape and gene regulatory network of pancreatic cancer are largely uncharacterized. Here, we integrate the chromatin accessibility profiles of 84 pancreatic cancer organoid lines with whole-genome sequencing data, transcriptomic sequencing data and the results of drug sensitivity analysis of 283 epigenetic-related chemicals and 5 chemotherapeutic drugs. We identify distinct transcription factors that distinguish molecular subtypes of pancreatic cancer, predict numerous chromatin accessibility peaks associated with gene regulatory networks, discover novel regulatory noncoding mutations with potential as cancer drivers, and reveal the chromatin accessibility signatures associated with drug sensitivity. These results not only provide the chromatin accessibility atlas of pancreatic cancer but also suggest a systematic approach to comprehensively understand the gene regulatory network of pancreatic cancer in order to advance diagnosis and potential personalized medicine applications.