Project description:14-3-3 proteins are ubiquitously expressed regulators of various cellular functions, including proliferation, metabolism, and differentiation, and altered 14-3-3 expression is associated with development and progression of cancer. We report a transforming 14-3-3 oncoprotein, which we identified through conventional cytogenetics and whole-transcriptome sequencing analysis as a highly recurrent genetic mechanism in a clinically aggressive form of uterine sarcoma: high-grade endometrial stromal sarcoma (ESS). The 14-3-3 oncoprotein results from a t(10;17) genomic rearrangement, leading to fusion between 14-3-3ε (YWHAE) and either of two nearly identical FAM22 family members (FAM22A or FAM22B). Expression of YWHAE-FAM22 fusion oncoproteins was demonstrated by immunoblot in t(10;17)-bearing frozen tumor and cell line samples. YWHAE-FAM22 fusion gene knockdowns were performed with shRNAs and siRNAs targeting various FAM22A exons in an t(10;17)-bearing ESS cell line (ESS1): Fusion protein expression was inhibited, with corresponding reduction in cell growth and migration. YWHAE-FAM22 maintains a structurally and functionally intact 14-3-3ε (YWHAE) protein-binding domain, which is directed to the nucleus by a FAM22 nuclear localization sequence. In contrast to classic ESS, harboring JAZF1 genetic fusions, YWHAE-FAM22 ESS display high-grade histologic features, a distinct gene-expression profile, and a more aggressive clinical course. Fluorescence in situ hybridization analysis demonstrated absolute specificity of YWHAE-FAM22A/B genetic rearrangement for high-grade ESS, with no fusions detected in other uterine and nonuterine mesenchymal tumors (55 tumor types, n = 827). These discoveries reveal diagnostically and therapeutically relevant models for characterizing aberrant 14-3-3 oncogenic functions.
Project description:NUTM1-rearranged tumors are defined by the presence of a gene fusion between NUTM1 and various gene partners and typically follow a clinically aggressive disease course with poor outcomes despite conventional multimodality therapy. NUTM1-rearranged tumors display histologic features of a poorly differentiated carcinoma with areas of focal squamous differentiation and typically express the BRD4-NUTM1 fusion gene defining a distinct clinicopathologic entity-NUT carcinoma (NC). NCs with mesenchymal differentiation have rarely been described in the literature. In this report, we describe the characterization of two cases of high-grade spindle cell sarcoma harboring a novel MGA-NUTM1 fusion. Whole-genome sequencing identified the presence of complex rearrangements resulting in a MGA-NUTM1 fusion gene in the absence of other significant somatic mutations. Genetic rearrangement was confirmed by fluorescence in situ hybridization, and expression of the fusion gene product was confirmed by transcriptomic analysis. The fusion protein was predicted to retain nearly the entire protein sequence of both MGA (exons 1-22) and NUTM1 (exons 3-8). Histopathologically, both cases were high-grade spindle cell sarcomas without specific differentiation markers. In contrast to typical cases of NC, these cases were successfully treated with aggressive local control measures (surgery and radiation) and both patients remain alive without disease. These cases describe a new subtype of NUTM1-rearranged tumors warranting expansion of diagnostic testing to evaluate for the presence of MGA-NUTM1 or alternative NUTM1 gene fusions in the diagnostic workup of high-grade spindle cell sarcomas or small round blue cell tumors of ambiguous lineage.
Project description:NUT carcinoma (NC) with mesenchymal differentiation have rarely been described in the literature. In this report, we describe the characterization of two cases of high grade spindle cell sarcoma harboring a novel MGA-NUTM1 fusion. Whole genome sequencing identified the presence of complex rearrangements resulting in a MGA-NUTM1 fusion gene in the absence of other significant somatic mutations. The fusion protein was predicted to retain nearly the entire protein sequence of both MGA (exons 1-22) and NUTM1 (exons 3-8). In contrast to typical cases of NC, these cases were successfully treated with aggressive local control measures (surgery and radiation) and both patients remain alive without disease. These cases describe a new subtype of NUTM1-rearranged tumors warranting expansion of diagnostic testing to evaluate for the presence of MGA-NUTM1 or alternative NUTM1 gene fusions in the diagnostic workup of high grade spindle cell sarcomas or small round blue cell tumors of ambiguous lineage.
Project description:Recurrent chromosomal translocations leading to gene fusion formation have been described in uterine sarcomas, including low-grade endometrial stromal sarcoma (LG-ESS). Involvement of the PHF1 gene in chromosomal rearrangements targeting band 6p21 has been found in LG-ESS with different partners from JAZF1 mapping in 7p15, to EPC1 from 10p11, MEAF6 from 1p34, and BRD8 from 5q31. In the present study, RNA sequencing of a LG-ESS showed a novel recombination of PHF1 with the Enhancer of Polycomb homolog 2 (EPC2). RT-PCR followed by Sanger sequencing and FISH analysis confirmed the EPC2-PHF1 fusion transcript.
Project description:Endometrial stromal sarcomas (ESSs) are a genetically heterogeneous group of rare uterine neoplasms that are frequently driven by recurrent gene rearrangements. In conventional low-grade ESSs, JAZF1-SUZ12, PHF1-JAZF1, EPC1-PHF1 and MEAF6-PHF1 chimeric fusions have been reported in >50% of cases. The recently described t(10;17)(q22;p13) translocation yields YWHAE-FAM22A/B chimeric proteins that are associated with histologically high-grade and clinically more aggressive ESS. Integrating whole-transcriptome paired-end RNA sequencing with fluorescence in situ hybridization (FISH) and conventional cytogenetics, we identified MBTD1 (Malignant Brain Tumor Domain-containing 1) and CXorf67 (Chromosome X open reading frame 67) as the genes involved in the novel reciprocal t(X;17)(p11.2;q21.33) translocation in two independent low-grade ESS of classical histology. The presence of the MBTD1-CXorf67 fusion transcript was validated in both cases using RT-PCR followed by Sanger sequencing. A specific FISH assay to be used on paraffin tissues was developed to detect the novel t(X;17) translocation, and resulted in identification of an additional low-grade ESS case positive for the MBTD1-CXorf67 fusion among 14 uterine stromal tumours [9 ESSs and 5 undifferentiated endometrial sarcomas (UESs)] that were negative for JAZF1 and YWHAE rearrangements. Gene expression profiles of 3 ESSs with YWHAE- and 4 classical ESSs with JAZF1-rearrangements, and 4 UESs without known gene rearrangements, indicated clustering of tumours with MBTD1-CXorf67 fusion together with low-grade JAZF1-associated ESSs. The chimeric MBTD1-CXorf67 fusion identifies yet another cytogenetically distinct subgroup of low-grade ESS and offers the opportunity to shed light on the functions of two poorly characterized genes. Total RNA was extracted from 11 frozen tumor samples from 4 low-grade ESS cases, 4 UES cases and 3 high-grade ESS cases; Agilent One-Color technology.
Project description:Pulmonary artery sarcomas are exceptionally rare, and they are often misdiagnosed as chronic pulmonary thromboemboli. Early and accurate diagnosis is crucial to the prognosis of patients who have pulmonary artery sarcomas.Herein, we describe the case of a 74-year-old man who presented with dyspnea and was initially thought to have a pulmonary embolus. Anticoagulation with unfractionated heparin was ineffective. Rare angiographic findings during routine cardiac catheterization led to the diagnosis of a high-grade, nonmyogenic, primary pulmonary artery sarcoma. This case illustrates the usefulness of angiographic findings as an adjunct to conventional diagnostic methods in correctly identifying this rare, aggressive malignancy.
Project description:Endometrial stromal sarcomas (ESSs) are a genetically heterogeneous group of rare uterine neoplasms that are frequently driven by recurrent gene rearrangements. In conventional low-grade ESSs, JAZF1-SUZ12, PHF1-JAZF1, EPC1-PHF1 and MEAF6-PHF1 chimeric fusions have been reported in > 50% of cases. The recently described t(10;17)(q22;p13) translocation yields YWHAE-FAM22A/B chimeric proteins that are associated with histologically high-grade and clinically more aggressive ESS. Integrating whole-transcriptome paired-end RNA sequencing with fluorescence in situ hybridization (FISH) and conventional cytogenetics, we identified MBTD1 (Malignant Brain Tumor Domain-containing 1) and CXorf67 (Chromosome X open reading frame 67) as the genes involved in the novel reciprocal t(X;17)(p11.2;q21.33) translocation in two independent low-grade ESS of classical histology. The presence of the MBTD1-CXorf67 fusion transcript was validated in both cases using RT-PCR followed by Sanger sequencing. A specific FISH assay to be used on paraffin tissues was developed to detect the novel t(X;17) translocation, and resulted in identification of an additional low-grade ESS case positive for the MBTD1-CXorf67 fusion among 14 uterine stromal tumours [9 ESSs and 5 undifferentiated endometrial sarcomas (UESs)] that were negative for JAZF1 and YWHAE rearrangements. Gene expression profiles of 3 ESSs with YWHAE- and 4 classical ESSs with JAZF1-rearrangements, and 4 UESs without known gene rearrangements, indicated clustering of tumours with MBTD1-CXorf67 fusion together with low-grade JAZF1-associated ESSs. The chimeric MBTD1-CXorf67 fusion identifies yet another cytogenetically distinct subgroup of low-grade ESS and offers the opportunity to shed light on the functions of two poorly characterized genes.