Project description:Here we profiled ten low-grade small intestine NET (SiNET) tumor samples as well as one mixed lung tumor by single-cell or single-nuclei RNA-seq. We find that SiNETs are largely separated into two distinct subtypes, in which the neuroendocrine cells upregulate epithelial or neuronal markers, respectively. Surprisingly, in both subtypes the neuroendocrine cells are largely non-proliferative while higher proliferation is observed in multiple non-malignant cell types. Specifically, B and plasma cells are highly proliferative in the epithelial-like SiNET subtype, potentially reflecting the outcome of high Migration Inhibitory Factor (MIF) expression in those tumors, which may constitute a relevant target. Finally, our analysis of a mixed lung neuroendocrine tumor identifies a population of putative progenitor cells that may give rise to both neuroendocrine and non-neuroendocrine (squamous) cells, potentially explaining the origin of the mixed histology. Taken together, our results provide important insights and hypotheses regarding the biology of neuroendocrine neoplasms.
Project description:Small intestine neuroendocrine tumors are the commonest neuroendocrine tumors of the GI tract. Next gen sequencing of the whole exome was undertaken to identify SNPs and SCNA in these tumor samples. Subsequent bioinformatic anlaysis was done where the reads ratios of tumor/normal were log2 tranformed, segments indentified with DNAcopy (R package) and regions of SCNA were identified. Amplification of chr 4, 5, 14 and 20 was observed. The validation of these SCNAs was done with arrayCGH. The results of array CGH is in concordeance with the exome sequencing data.
Project description:Small intestine neuroendocrine tumors are the commonest neuroendocrine tumors of the GI tract. Next gen sequencing of the whole exome was undertaken to identify SNPs and SCNA in these tumor samples. Subsequent bioinformatic anlaysis was done where the reads ratios of tumor/normal were log2 tranformed, segments indentified with DNAcopy (R package) and regions of SCNA were identified. Amplification of chr 4, 5, 14 and 20 was observed. The validation of these SCNAs was done with arrayCGH. The results of array CGH is in concordeance with the exome sequencing data. DNA from matched tumor and normal sample of SI-NETs was done by spin column method. Libraries were constructed and exome enriched for next gen sequencing. The same gDNA was hybridized with Cy5 and Cy3 and subsequent analysis was done. This study represents the CGH portion of the study.
Project description:<p>The diagnosed incidence of small bowel neuroendocrine tumors (NETs) is increasing. While patients with localized disease can be treated surgically, those with metastatic disease currently have few treatment options. The success of biologically targeted therapies in other malignancies has led to interest in the molecular alterations underlying the pathogenesis of these NETs. To identify genetic aberrations in small intestine NETs, we generated copy number profiles from 31 primary and metastatic tumors and performed whole-exome sequencing on a subset of 29 primary small intestine NETs and 24 metastatic NETs in parallel with normal blood DNA. Whole-genome sequencing data was generated on 15 tumor/normal pairs and 5 primary/metastasis/normal trios. The global genetic landscape of small bowel NETs is relatively quiet. Consistent with previous studies, the overwhelming majority of tumors were characterized by loss of chromosome 18 and, to a lesser extent, other chromosome arm gains and losses. In stark contrast to arm-level alterations, recurrent high-level focal amplifications and deletions were much less prevalent in these tumors. High-throughput mutation screening and exome sequencing revealed similarly low rates of somatic mutation in NETs (median of 0.77 non-silent mutations per megabase (Mb) of coding DNA) compared to other recent cancer exome sequencing efforts. Our analysis of this cohort identified only a single, statistically significant recurrent somatic mutation targeting the cyclin-dependent kinase inhibitor gene, CDKN1B, encoding p27. </p>
Project description:We sought to define the gene expression profiles of small intestine neuroendocrine tumors (SI-NETs) in order to identify clinically relevant subgroups of tumors, prognostic markers and novel targets for treatment.
Project description:<p>The diagnosed incidence of small bowel neuroendocrine tumors (NETs) is increasing. While patients with localized disease can be treated surgically, those with metastatic disease currently have few treatment options. The success of biologically targeted therapies in other malignancies has led to interest in the molecular alterations underlying the pathogenesis of these NETs. To identify genetic aberrations in small intestine NETs, we generated copy number profiles from 31 primary and metastatic tumors and performed whole-exome sequencing on a subset of 29 primary small intestine NETs and 24 metastatic NETs in parallel with normal blood DNA. Whole-genome sequencing data was generated on 15 tumor/normal pairs and 5 primary/metastasis/normal trios. The global genetic landscape of small bowel NETs is relatively quiet. Consistent with previous studies, the overwhelming majority of tumors were characterized by loss of chromosome 18 and, to a lesser extent, other chromosome arm gains and losses. In stark contrast to arm-level alterations, recurrent high-level focal amplifications and deletions were much less prevalent in these tumors. High-throughput mutation screening and exome sequencing revealed similarly low rates of somatic mutation in NETs (median of 0.77 non-silent mutations per megabase (Mb) of coding DNA) compared to other recent cancer exome sequencing efforts. Our analysis of this cohort identified only a single, statistically significant recurrent somatic mutation targeting the cyclin-dependent kinase inhibitor gene, CDKN1B, encoding p27. </p>
Project description:Small intestinal neuroendocrine tumors (SI-NETs) arise from serotonin-producing enterochromaffin cells. SI-NETs are often well-differentiated tumors and most patients have regional or distant metastases at initial presentation. MicroRNAs (miRs) are post-transcriptional regulators which are important in diverse biological processes and can function as tumor suppressor genes or oncogenes. This study aims to identify an exclusive SI-NETs miR profile that may have a critical role in development, diagnosis, prognosis and progression of these malignancies.
Project description:Assessment of mesenteric fibrosis (MF) presence and severity in small-intestinal neuroendocrine tumors (SI-NETs) remains a diagnostic challenge. To explore possible biomarkers for MF presence, a proteomic analysis was performed of the tumor and stroma compartment of primary SI-NETs and paired mesenteric metastasis.
Project description:Urinary measure of 5-hydroxyindolacetic acid (5HIAA) is an important marker for the diagnosis and follow-up of patients with small-intestine neuroendocrine tumors. Although this marker has good specificity, its sensitivity is moderate and its dosage is constraining, since it requires urine collection over 2-3 days and specific diet. Preliminary data suggested that overnight 5HIAA value may be representative of 24-hour 5HIAA value, and that plasma 5HIAA dosage could be a valuable alternative to urine 5HIAA dosage. The main objective of this study is to compare sensitivity and specificity of overnight 5HIAA value, 24-hour 5HIAA value and plasma 5HIAA value, in patients with small-intestine neuroendocrine tumors.