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Kristin Sikkink

Publications and source records attributed to Kristin Sikkink.

5 recordsLinked to original sources

Genomic Characterization of Classic Adamantinoma, Osteofibrous Dysplasia, and Osteofibrous Dysplasia-like Adamantinoma.

Classic adamantinoma, osteofibrous dysplasia (OFD), and OFD-like adamantinoma are rare bone tumors arising primarily in the tibiae. Their distinction can be challenging; data on their molecular pathogenesis remain limited. We searched our pathology files in 2004-2024 for available cases and performed targeted next-generation sequencing along with whole-genome single-nucleotide polymorphism arrays and 3-dimensional genomics/Hi-C sequencing in selected cases. Our cohort included 3 classic adamantinomas (2 females and 1 male; age, 14-56 years), 5 OFDs (3 females and 2 males; age, 9-25 years), and 2 OFD-like adamantinomas (1 female and 1 male; age, 30-41 years). Of the 10 tumors, 9 arose from the tibiae; 1 classic adamantinoma originated from the radius. The 3 classic adamantinomas harbored multiple copy number gains involving chromosome 7, 8, 10, 12, and/or 19. Focal deletion of chromosome 17, intergenic rearrangement involving FGFR1, and NRAS p.G12D were each present in 1 classic adamantinoma. Of the 5 OFDs, KMT2A p.C2441F, KMT2D p.S1040P, PHOX2B p.G213D, and RIF1 deletion were each present in 1 case; no additional copy number/single-nucleotide variants were identified. Of the 2 OFD-like adamantinomas, one case with tumor clusters visible only on cytokeratin immunostain harbored no variants, whereas another case with tumor clusters visible on light microscopy and cytokeratin/p40 immunostains showed gains of chromosome 7, 8, 19, and 20. By Hi-C, 1 classic adamantinoma harbored an approximately 9 Mb tandem duplication on chromosome 12q, 1 OFD harbored a rearrangement with breakpoints near MECOM and HOOK3, and the OFD-like adamantinoma with tumor clusters visible only on cytokeratin immunostain harbored no structural variant. In conclusion, classic adamantinomas and OFD might be genetically distinct. Classic adamantinomas harbored multiple alterations, including chromosome/arm-level copy number gains, the detection of which could aid their distinction from OFDs. Using genomics as the benchmark, OFD-like adamantinomas might be better delineated by light microscopy or p40 than by cytokeratin immunohistochemistry. These data expanded our molecular understanding of these rare bone tumors.

Humans

Development and extensive sequencing of a broadly-consented Genome in a Bottle matched tumor-normal pair.

The Genome in a Bottle Consortium (GIAB), hosted by the National Institute of Standards and Technology (NIST), is developing new matched tumor-normal samples, the first explicitly consented for public dissemination of genomic data and cell lines. Here, we describe a comprehensive genomic dataset from the first individual, HG008, including DNA from an adherent, epithelial-like pancreatic ductal adenocarcinoma (PDAC) tumor cell line and matched normal cells from duodenal and pancreatic tissues. Data for the tumor-normal matched samples comes from seventeen distinct state-of-the-art whole genome measurement technologies, including high depth short and long-read bulk whole genome sequencing (WGS), single cell WGS, Hi-C, and karyotyping. These data will be used by the GIAB Consortium to develop matched tumor-normal benchmarks for somatic variant detection. We expect these data to facilitate innovation for whole genome measurement technologies, de novo assembly of tumor and normal genomes, and bioinformatic tools to identify small and structural somatic variants. This first-of-its-kind broadly consented open-access resource will facilitate further understanding of sequencing methods used for cancer biology.

Humans

Development and extensive sequencing of a broadly-consented Genome in a Bottle matched tumor-normal pair.

The Genome in a Bottle Consortium (GIAB), hosted by the National Institute of Standards and Technology (NIST), is developing new matched tumor-normal samples, the first to be explicitly consented for public dissemination of genomic data and cell lines. Here, we describe a comprehensive genomic dataset from the first individual, HG008, including DNA from an adherent, epithelial-like pancreatic ductal adenocarcinoma (PDAC) tumor cell line and matched normal cells from duodenal and pancreatic tissues. Data for the tumor-normal matched samples comes from seventeen distinct state-of-the-art whole genome measurement technologies, including high depth short and long-read bulk whole genome sequencing (WGS), single cell WGS, and Hi-C, and karyotyping. In future publications, these data will be used by the GIAB Consortium to develop matched tumor-normal benchmarks for somatic variant detection. We expect these data to facilitate innovation for whole genome measurement technologies, de novo assembly of tumor and normal genomes, and bioinformatic tools to identify small and structural somatic mutations. This first-of-its-kind broadly consented open-access resource will facilitate further understanding of sequencing methods used for cancer biology.

Journal Article

3D genome mapping identifies subgroup-specific chromosome conformations and tumor-dependency genes in ependymoma.

Ependymoma is a tumor of the brain or spinal cord. The two most common and aggressive molecular groups of ependymoma are the supratentorial ZFTA-fusion associated and the posterior fossa ependymoma group A. In both groups, tumors occur mainly in young children and frequently recur after treatment. Although molecular mechanisms underlying these diseases have recently been uncovered, they remain difficult to target and innovative therapeutic approaches are urgently needed. Here, we use genome-wide chromosome conformation capture (Hi-C), complemented with CTCF and H3K27ac ChIP-seq, as well as gene expression and DNA methylation analysis in primary and relapsed ependymoma tumors, to identify chromosomal conformations and regulatory mechanisms associated with aberrant gene expression. In particular, we observe the formation of new topologically associating domains ('neo-TADs') caused by structural variants, group-specific 3D chromatin loops, and the replacement of CTCF insulators by DNA hyper-methylation. Through inhibition experiments, we validate that genes implicated by these 3D genome conformations are essential for the survival of patient-derived ependymoma models in a group-specific manner. Thus, this study extends our ability to reveal tumor-dependency genes by 3D genome conformations even in tumors that lack targetable genetic alterations.

Child