NUP214 fusion genes in acute leukemias: genetic characterization of rare cases.

Introduction: Alterations of the NUP214 gene (9q34) are recurrent in acute leukemias. Rearrangements of chromosomal band 9q34 targeting this locus can be karyotypically distinct, for example t(6;9)(p22;q34)/DEK::NUP214, or cryptic, in which case no visible change of 9q34 is seen by chromosome banding. Methods: We examined 9 cases of acute leukemia with NUP214 rearrangement by array Comparative Genomic Hybridization (aCGH), reverse-transcription polymerase chain reaction (RT-PCR), and cycle sequencing/Sanger sequencing to detect which fusion genes had been generated. Results: The chimeras DEK::NUP214, SET::NUP214, and NUP214::ABL1 were found, only the first of which can be readily detected by karyotyping. Discussion: The identification of a specific NUP214 rearrangement is fundamental in the management of these patients, i.e., AMLs with DEK::NUP214 are classified as an adverse risk group and might be considered for allogenic transplant. Genome- and/or transcriptome-based next generation sequencing (NGS) techniques can be used to screen for these fusions, but we hereby present an alternative, step-wise procedure to detect these rearrangements.

Genetic characterization of intramuscular myxomas.

Introduction: Intramuscular myxomas are benign tumors that are challenging to diagnose, especially on core needle biopsies. Acquired chromosomal aberrations and pathogenic variants in codon 201 or codon 227 in GNAS complex locus gene (GNAS) have been reported in these tumors. Here we present our genetic findings in a series of 22 intramuscular myxomas. Materials and methods: The tumors were investigated for the presence of acquired chromosomal aberrations using G-banding and karyotyping. Pathogenic variants in codon 201 or codon 227 of GNAS were assessed using direct cycle Sanger sequencing and Ion AmpliSeq Cancer Hotspot Panel v2 methodologies. Results: Eleven tumors carried chromosomal abnormalities. Six tumors had numerical, four had structural, and one had both numerical and structural chromosomal aberrations. Gains of chromosomes 7 and 8 were the most common abnormalities being found in five and four tumors respectively. Pathogenic variants in GNAS were detected in 19 myxomas (86%) with both methodologies. The detected pathogenic variants were p.R201H in nine cases (seven with abnormal and two with normal karyotypes), p.R201C in five cases, all with normal karyotypes, p.R201S in three cases (two with abnormal and one with normal karyotype), p.R201G in one case with a normal karyotype, and p.Q227E in one case with a normal karyotype. Conclusion: Firstly, our data indicate a possible association between chromosomal abnormalities and GNAS pathogenic variants in intramuscular myxomas. Secondly, the presence of the rare pathogenic variants R201S, p.R201G and p.Q227E in 26% (5 out of 19) of myxomas with GNAS pathogenic variants shows that methodologies designed to detect only the common "hotspot" of p.R201C and p.R201H will give false negative results. Finally, a comparison between Ion AmpliSeq Cancer Hotspot Panel v2 and direct cycle Sanger sequencing showed that direct cycle Sanger sequencing provides a quick, reliable, and relatively cheap method to detect GNAS pathogenic variants, matching even the most cutting-edge sequencing methods.

Pathogenetic Dichotomy in Angioleiomyoma.

BACKGROUND/AIM: Angioleiomyoma is a benign tumor, occurs at any age, and arises most frequently in the lower extremities. Genetic information on angioleiomyomas is restricted to six reported abnormal karyotypes, losses in chromosome 22 and gains in Xq found by comparative genomic hybridization, and mutation analysis of notch receptor 2 (NOTCH2), NOTCH3, platelet-derived growth factor receptor beta (PDGFRB), and mediator complex subunit 12 (MED12) in a few tumors. Herein, we report the genetic findings in another three angioleiomyomas. MATERIALS AND METHODS: The tumors were examined using G-banding and karyotyping, RNA sequencing, reverse transcription-polymerase chain reaction, Sanger sequencing, and expression analysis. RESULTS: The first tumor carried a t(4;5)(p12;q32) translocation resulting in fusion of the cardiac mesoderm enhancer-associated non-coding RNA (CARMN in 5q32) with the TXK tyrosine kinase gene (TXK in 4p12) leading to overexpression of TXK. To our knowledge, this is the first time that a recurrent chromosome translocation and its resulting fusion gene have been described in angioleiomyomas. The second tumor carried a four-way translocation, t(X;3;4;16)(q22;p11;q11;p13) which fused the myosin heavy chain 11 gene (MYH11 in 16p13) with intergenic sequences from Xq22 that mapped a few kilobase pairs distal to the insulin receptor substrate 4 gene (IRS4), resulting in enhanced IRS4 expression. The third angioleiomyoma carried another rearrangement of chromosome band Xq22, t(X;9)(q22;q32), as the sole cytogenetic aberration, but no material was available for further molecular investigation. CONCLUSION: Our data, together with previously reported abnormal karyotypes in angioleiomyomas, show the presence of two recurrent genetic pathways in this tumor type: The first is characterized by presence of the translocation t(4;5)(p12;q32), which generates a CARMN::TXK chimera. The second is recurrent rearrangement of Xq22 resulting in overexpression of IRS4.

Genetic Pathways in Peritoneal Mesothelioma Tumorigenesis.

BACKGROUND/AIM: Mesotheliomas are tumors similar to, and probably derived from, mesothelial cells. They carry acquired chromosomal rearrangements, deletions affecting CDKN2A, pathogenetic polymorphisms in NF2, and fusion genes which often contain the promiscuous EWSR1, FUS, and ALK as partner genes. Here, we report the cytogenomic results on two peritoneal mesotheliomas. MATERIALS AND METHODS: Both tumors were examined using G-banding with karyotyping and array comparative genomic hybridization (aCGH). One of them was further investigated with RNA sequencing, reverse transcription polymerase chain reaction (RT-PCR), Sanger sequencing, and fluorescence in situ hybridization (FISH). RESULTS: In the first mesothelioma, the karyotype was 25∼26,X,+5,+7,+20[cp4]/50∼52,idemx2[cp7]/46,XX[2]. aCGH detected gains of chromosomes 5, 7, and 20 with retained heterozygosity on these chromosomes. In the second tumor, the karyotype was 46,XX,inv(10)(p11q25)[7]/46,XX[3]. aCGH did not detect any gains or losses and showed heterozygosity for all chromosomes. RNA sequencing, RT-PCR/Sanger sequencing, and FISH showed that the inv(10) fused MAP3K8 from 10p11 with ABLIM1 from 10q25. The MAP3K8::ABLIM1 chimera lacked exon 9 of MAP3K8. CONCLUSION: Our data, together with information on previously described mesotheliomas, illustrate two pathogenetic mechanisms in peritoneal mesothelioma: One pathway is characterized by hyperhaploidy, but with retained disomies for chromosomes 5, 7, and 20; this may be particularly prevalent in biphasic mesotheliomas. The second pathway is characterized by rearrangements of MAP3K8 from which exon 9 of MAP3K8 is lost. The absence of exon 9 from oncogenetically rearranged MAP3K8 is a common theme in thyroid carcinoma, lung cancer, and spitzoid as well as other melanoma subtypes.

Fusion of the High-mobility Group AT-Hook 2 (HMGA2) and the Gelsolin (GSN) Genes in Lipomas With t(9;12)(q33;q14) Chromosomal Translocation.

BACKGROUND/AIM: Lipomas are benign tumors composed of mature fat cells. They are common soft tissue tumors that often carry chromosome aberrations involving 12q14 resulting in rearrangements, deregulation, and generation of chimeras of the high-mobility group AT-hook 2 gene (HMGA2) which maps in 12q14.3. In the present study, we report the finding of t(9;12)(q33;q14) translocation in lipomas and describe its molecular consequences. MATERIALS AND METHODS: Four lipomas from two male and two female adult patients were selected because their neoplastic cells carried a t(9;12)(q33;q14) as the sole karyotypic aberration. The tumors were investigated using RNA sequencing, reverse transcription polymerase chain reaction (RT-PCR), and Sanger sequencing techniques. RESULTS: RNA sequencing of a t(9;12)(q33;q14)-lipoma detected an in-frame fusion of HMGA2 with the gelsolin gene (GSN) from 9q33. RT-PCR together with Sanger sequencing confirmed the presence of an HMGA2::GSN chimera in the tumor as well as in two other tumors from which RNA was available. The chimera was predicted to code for an HMGA2::GSN protein which would contain the three AT-hook domains of HMGA2 and the entire functional part of GSN. CONCLUSION: t(9;12)(q33;q14) is a recurrent cytogenetic aberration in lipomas and generates an HMGA2::GSN chimera. Similar to what is seen in other rearrangements of HMGA2 in mesenchymal tumors, the translocation physically separates the part of HMGA2 encoding AT-hook domains from the gene's 3'-terminal part which contains elements that normally regulate HMGA2 expression.

Endometrial Carcinoma: Molecular Cytogenetics and Transcriptomic Profile.

Endometrial carcinomas (ECs) are histologically classified as endometrioid and nonendometrioid tumors, with each subgroup displaying different molecular profiles and clinical outcomes. Considerable biological and clinical heterogeneity exists within this scheme, however, reflecting its imperfection. We aimed to gather additional data that might help clarify the tumors' pathogenesis and contribute toward a more meaningful classification scheme. In total, 33 ECs were examined for the presence of chromosomal aberrations, genomic imbalances, pathogenic variants, microsatellite instability, and expression profiles at both gene and miRNA levels. Chromosome 1 was the most frequently rearranged chromosome, showing a gain of all or part of the long arm. Pathogenic variants were found for PTEN (53%), PDGFRA (37%), PIK3CA (34%), and KIT (31%). High microsatellite instability was identified in 15 ECs. Comparing tumors and controls, we identified 23 differentially expressed genes of known importance in carcinogenesis, 15 genes involved in innate and adaptative immune responses, and altered expression of 7 miRNAs. miR-32-5p was the most upregulated. Our series showed a high degree of heterogeneity. Tumors were well-separated from controls, but there was no clear-cut separation between endometrioid and nonendometrioid ECs. Whether this means that the current phenotypic classification is of little relevance or if one still has not detected which genomic parameters to enter into correlation analyses remains unknown.

Diagnostic utility of Restriction Spectrum Imaging in the characterization of the peritumoral brain zone in glioblastoma: Analysis of overall and progression-free survival.

PURPOSE: We studied the ability of Restriction Spectrum Imaging (RSI), a novel advanced diffusion imaging technique, to estimate levels of cellularity in different glioblastoma regions, evaluated their prognostic value compared with established clinical diffusion metrics such as fractional anisotropy (FA) and mean diffusivity (MD). METHODS: Forty-two patients with untreated glioblastoma, IDH-wildtype, were examined with an advanced MRI tumor protocol. The region of interest (ROI) was obtained from the contrast-enhancing part of tumor and the peritumoral brain zones and then co-registered with RSI-cellularity index, FA and MD maps. Histogram parameters of diffusion metrics were assessed for all ROI locations and compared to MGMT promoter methylation status and survival. The ability of RSI-cellularity index, FA, and MD to stratify survival and were assessed by Cox proportional hazard regression, adjusted for significant clinical predictors. RESULTS: The highest RSI-cellularity index was measured in contrast-enhancing tumor core with a negative gradient from tumor core to the periphery of peritumoral zone with predictive accuracy 81 % (P < 0.001). Shorter overall survival was significant associated with higher RSI-cellularity index (hazard ratio (HR) 3.6, 95 % confidence interval (CI) 1.3-9.5, P = 0.002) with synchronal decrease in MD (HR 0.31, 95 %CI 0.1-0.8, P = 0.008) in the contrast-enhanced tumor core. This association was also consistent for RSI-cellularity index value measured in the peri-enhancing zone (HR 3.6, 95 % CI 1.0-12.3, P = 0.041). No statistically significant differences were noted between RSI-cellularity index, FA, nor MD and MGMT promoter methylation. CONCLUSION: RSI-cellularity index may be used as prognostic biomarker to improve risk stratification in patients with glioblastoma.

TYRO3 Truncation Resulting From a t(10;15)(p11;q15) Chromosomal Translocation in Pediatric Acute Myeloid Leukemia.

BACKGROUND/AIM: Novel acquired chromosome aberrations in cancer may provide insights into pathogenetic mechanisms, be of diagnostic and/or prognostic significance and pave the way for new modes of therapeutic intervention. Here, we report a novel chromosome translocation and its molecular genetic consequences in a pediatric acute myeloid leukemia (AML) case. MATERIALS AND METHODS: Cytogenetic, RNA sequencing, and molecular analyses were performed on the bone marrow cells of a child with AML. RESULTS: The patient entered complete hematologic remission after treatment according to the NOPHO-AML 2004 protocol. A novel t(10;15)(p11;q15) translocation was found in leukemic cells at diagnosis resulting in a fusion of exon 13 of TYRO3 with a sequence from 10p11. The transcript codes for a putative TYRO3 protein lacking the tyrosine kinase domain. CONCLUSION: The t(10;15)(p11;q15) translocation in neoplastic bone marrow cells results in truncated TYRO3. Because the role of the truncated TYRO3 cannot be predicted functional studies are required.

Mutation analysis and genomic imbalances of cells found in effusion fluids from patients with ovarian cancer.

Ovarian carcinomas and carcinosarcomas often cause malignant effusions, an accumulation within serous cavities of fluid containing cancer cells. Few studies have focused on the molecular alterations and genetic mechanisms behind effusion formation. The present study investigated the mutation status of TP53, PIK3CA, KRAS, HRAS, NRAS and BRAF in effusion fluids from 103 patients with ovarian cancer. In addition, array Comparative Genomic Hybridization (aCGH) analysis was performed on 20 effusions from patients with high-grade serous carcinoma (10 cases positive for TP53 mutation and 10 with TP53 wild-type). TP53 mutations, two of which were novel: c.826_830delCCTGT and c.475_476GC>TT, were identified in 44% of the cases. Mutations in KRAS, HRAS, and PIK3CA were identified in two, two and four cases, respectively. None of the effusions analysed showed NRAS or BRAF mutations. The aCGH analysis revealed highly imbalanced genomes similar to those described in primary ovarian carcinomas. No specific profile was indicated to distinguish tumors with TP53 mutations from those without. The molecular profiling of cells found in effusion fluids from patients with ovarian cancer thus showed considerable molecular heterogeneity. TP53 seems to be the most frequently mutated gene in these cells and may serve a leading role in the metastatic process.

Death domain-associated protein (DAXX) expression is associated with poor survival in metastatic high-grade serous carcinoma.

The objective of this study was to analyze the expression and clinical role of mitosis regulators α-thalassemia/mental retardation syndrome X-linked (ATRX) and death-domain-associated protein (DAXX) in metastatic high-grade serous carcinoma (HGSC). ATRX and DAXX protein expression by immunohistochemistry was analyzed in 400 HGSC effusions. DAXX expression was additionally studied in 15 cancer cell lines, including 4 ovarian carcinoma lines, and in 81 of the 400 HGSC effusions using Western blotting. ATRX and DAXX were expressed in HGSC cells in 386/400 (96%) and 348/400 (87%) effusions, respectively. Western blotting showed DAXX expression in all 15 cell lines and in 70/81 (86%) HGSC effusions. DAXX expression by immunohistochemistry was higher in pleural compared to peritoneal effusions (p = 0.006) and in post-chemotherapy compared to pre-chemotherapy effusions (p = 0.004), and its expression was significantly associated with poor overall survival in univariate of the entire cohort (p = 0.014), as well as analysis limited to chemo-naïve effusions tapped at diagnosis (p = 0.038). The former association retained its prognostic role in Cox multivariate survival analysis (p = 0.011). ATRX expression was unrelated to clinicopathologic parameters or survival. In conclusion, DAXX is associated with disease progression and could be a prognostic marker in metastatic HGSC. Silencing this molecule may have therapeutic relevance in this cancer.

MGMT promoter methylation is a rare epigenetic change in malignant effusions.

OBJECTIVE: The aim of this study was to analyse the promoter methylation status of the gene O6-methylguanine-DNA methyltransferase (MGMT) in malignant effusions, with focus on serous carcinoma. METHODS: Fresh-frozen cell pellets from 81 effusions (42 peritoneal, 38 pleural, one pericardial), consisting of 71 carcinomas of different origin (33 ovarian, 23 breast, six lung, five uterine corpus and four cervical carcinomas) and 10 malignant mesotheliomas, were analysed for MGMT methylation using pyrosequencing analysis. RESULTS: MGMT methylation at all four cytosine-guanine dinucleotide sites examined was detected in only 2/81 (2%) specimens, consisting of a high-grade serous carcinoma with high frequency of methylation, and a breast carcinoma with low methylation frequency. CONCLUSION: The findings in the present study suggest that MGMT methylation is a rare epigenetic change in malignant effusions of different origin.

Novel GTF2I-PDGFRB and IKZF1-TYW1 fusions in pediatric leukemia with normal karyotype.

BACKGROUND: Many cases of acute lymphoblastic leukemia (ALL) carry visible acquired chromosomal changes of pathogenetic, diagnostic, and prognostic importance. Nevertheless, from one-fourth to half of newly diagnosed ALL patients have no visible chromosomal changes detectable by G-banding analysis at diagnosis. The introduction of powerful molecular methodologies has shown that many karyotypically normal ALLs carry clinically important submicroscopic aberrations. CASE PRESENTATION: We used fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH), RNA sequencing, reverse transcription (RT) and genomic polymerase chain reaction (PCR), as well as Sanger sequencing to investigate a case of pediatric ALL with a normal karyotype. FISH with a commercial PDGFRB breakapart probe showed loss of the distal part of the probe suggesting a breakpoint within the PDGFRB locus. aCGH revealed submicroscopic deletions in chromosome bands 5q32q35.3 (about 30 Mb long, starting within PDGFRB and finishing in the CANX locus), 7q34 (within TCRB), 9p13 (PAX5), 10q26.13 (DMBT1), 14q11.2 (TRAC), and 14q32.33 (within the IGH locus). RNA sequencing detected an in-frame GTF2I-PDGFRB and an out-of-frame IKZF1-TYW1 fusion transcript. Both fusion transcripts were verified by RT-PCR together with Sanger sequencing and interphase FISH. The GTF2I-PDGFRB fusion was also verified by genomic PCR and FISH. The corresponding GTF2I-PDGFRB fusion protein would consist of almost the entire GTF2I and that part of PDGFRB which harbors the catalytic domain of the tyrosine kinase. It would therefore seem to lead to abnormal tyrosine kinase activity in a manner similar to what has been seen for other PDGFRB fusion proteins. CONCLUSIONS: The examined pediatric leukemia is a Ph-like ALL which carries novel GTF2I-PDGFRB and IKZF1-TYW1 fusion genes together with additional submicroscopic deletions. Because hematologic neoplasms with PDGFRB-fusion genes can be treated with tyrosine kinase inhibitors, the detection of such novel fusions may be clinically important. Since the GTF2I-PDGFRB could be detected only after molecular studies of the leukemic cells, further investigations of ALL-cases, perhaps especially but not exclusively with a normal karyotype, are needed in order to determine the frequency of GTF2I-PDGFRB in leukemia, and also to find out which clinical impact the fusion may have.

Molecular characterization of carcinosarcomas arising in the uterus and ovaries.

Gynaecological carcinosarcomas are rare biphasic tumours which are highly aggressive. We performed molecular investigations on a series of such tumours arising in the uterus (n = 16) and ovaries (n = 10) to gain more information on their mutational landscapes and the expression status of the genes HMGA1/2, FHIT, LIN28A, and MTA1, the pseudogenes HMGA1P6 and HMGA1P7, and the miRNAs known to influence expression of the above-mentioned genes. In uterine carcinosarcomas (UCS), we identified mutations in KRAS, PIK3CA, and TP53 with a frequency of 6%, 31%, and 75%, respectively, whereas in ovarian carcinosarcomas (OCS), TP53 was the only mutated gene found (30%). An inverse correlation was observed between overexpression of HMGA1/2, LIN28A, and MTA1 and downregulation of miRNAs such as let-7a, let-7d, miR26a, miR16, miR214, and miR30c in both UCS and OCS. HMGA2 was expressed in its full length in 14 UCS and 9 OCS; in the remaining tumours, it was expressed in its truncated form. Because FHIT was normally expressed while miR30c was downregulated, not both downregulated as is the case in several other carcinomas, alterations of the epithelial-mesenchymal transition through an as yet unknown mechanism seems to be a feature of carcinosarcomas.

Expression and clinical role of the dipeptidyl peptidases DPP8 and DPP9 in ovarian carcinoma.

Dipeptidyl peptidase 9 (DPP9) was recently identified as fusion gene in ovarian high-grade serous carcinoma (HGSC). The aim of this study was to analyze the expression and clinical relevance of DPP8 and DPP9 in ovarian carcinoma, with focus on HGSC. mRNA expression by qRT-PCR of DPP8 and DPP9 was analyzed in 232 carcinomas, including 114 effusions and 118 surgical specimens (89 ovarian, 29 solid metastases). DPP8 and DPP9 protein expression was analyzed in 92 effusions. DPP8 and DPP9 mRNA was overexpressed in effusions compared to solid lesions in analysis of all histotypes (p < 0.001 both), as well as in analysis limited to HGSC (p < 0.001 for DPP9, p = 0.002 for DPP8). DPP9 mRNA was additionally overexpressed in HGSC compared to other histotypes (p = 0.021). DPP8 and DPP9 protein was expressed in carcinoma cells in 31/92 (37%) and 81/92 (88%) effusions, respectively. DPP8 protein expression in HGSC effusions was significantly related to better (complete) chemoresponse at diagnosis (p = 0.005). DPP8 and DPP9 mRNA and protein expression was unrelated to survival in analysis of the entire effusion cohort. However, higher DPP9 mRNA levels were significantly related to longer overall survival in pre-chemotherapy effusions (p = 0.049). In conclusion, DPP8 and DPP9 mRNA is frequently expressed in ovarian carcinoma, whereas DPP9 is more frequently expressed at the protein level. DPP8 and DPP9 may be related to less aggressive disease in advanced-stage HGSC.

Primary mediastinal choriocarcinoma in a female patient: Case report and review of the literature.

•Primary mediastinal choriocarcinoma is rare, especially in female patients.•Genomic losses predominated our case, which has not been previously reported.•This tumor lacked human chorionic gonadotropin and required histologic diagnosis.

The microRNA miR-192/215 family is upregulated in mucinous ovarian carcinomas.

Different microRNAs are dysregulated in ovarian cancer where some of them have proved to be valid biomarkers. miRNA profiling analyses have shown that the different histotypes of ovarian carcinoma display differential expression of specific miRNAs. In the present study, we used miRNA-sequencing and Real-Time qPCR to detect the expression levels of miRNAs belonging to the miRNA-192/215 family, namely miR-192, miR-194, and miR-215, in different types of ovarian neoplasia, finding that miR-192, miR-194, and miR-215 were upregulated in ovarian carcinomas of the mucinous subtype, but downregulated in other types of carcinoma and in sex cord-stromal tumors. The expression of the said miRNAs was 6-fold higher in mucinous tumors compared to the other histotypes making them candidates for a possible role as diagnostic biomarkers.

Identification of an EPC2-PHF1 fusion transcript in low-grade endometrial stromal sarcoma.

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.

Identification of novel cyclin gene fusion transcripts in endometrioid ovarian carcinomas.

Formation of fusion genes is pathogenetically crucial in many solid tumors. They are particularly characteristic of several mesenchymal tumors, but may also be found in epithelial neoplasms. Ovarian carcinomas, too, may harbor fusion genes but only few of these were found to be recurrent with a rate ranging from 0.5 to 5%. Because most attempts to find specific and recurrent fusion transcripts in ovarian carcinomas focused exclusively on high-grade serous carcinomas, the situation in the other carcinoma subgroups remains largely uninvestigated as far as fusion genes are concerned. We performed transcriptome sequencing on a series of 34 samples from ovarian tumors that included borderline, clear cell, mucinous, endometrioid, low-grade and high-grade serous carcinomas in search of fusion genes typical of these subtypes. We found a total of 24 novel fusion transcripts. The PCMTDI-CCNL2 fusion transcript, which involves a member of the cyclin family, was found recurrently involved but only in endometrioid carcinomas (4 of 18 tumors; 22%). We also found three additional fusion transcripts involving genes belonging to the cyclin family: ANXA5-CCNA2 and PDE4D-CCNB1 were detected in two endometrioid carcinomas, whereas CCNY-NRG4 was identified in a clear cell carcinoma. The recurrent involvement of CCNL2 in four fusions and of three other genes of the cyclin family in three additional transcripts hints that deregulation of cyclin genes is important in the pathogenesis of ovarian carcinomas in general but of endometrioid carcinomas particularly.

RNA-sequencing identifies novel GREB1-NCOA2 fusion gene in a uterine sarcoma with the chromosomal translocation t(2;8)(p25;q13).

Sarcomas account for 3% of all uterine malignancies and many of them are characterized by acquired, specific fusion genes whose detection has increased pathogenetic knowledge and diagnostic precision. We describe a novel fusion gene, GREB1-NCOA2, detected by transcriptome sequencing and validated by reverse transcriptase polymerase chain reaction and Sanger sequencing in an undifferentiated uterine sarcoma. The chimeric transcript was an in-frame fusion between exon 3 of GREB1 and exon 15 of NCOA2. The fusion is reported here for the first time, but it involves the GREB1 gene, an important promoter of tumor growth and progression, and NCOA2 which is known to be involved in transcriptional regulation. The alteration and recombination of these genes played a role in the tumorigenesis and/or progression of this sarcoma.

Fusion of the genes BRD8 and PHF1 in endometrial stromal sarcoma.

We present a new endometrial stromal sarcoma (ESS)-associated genomic rearrangement involving chromosome arms 5p and 6p and leading to the formation of a BRD8-PHF1 fusion gene. The PHF1 (PHD finger protein 1) gene, from 6p21, is known to be rearranged in ESS in a promiscuous way inasmuch as it has been shown to recombine with JAZF1, EPC1, MEAF6, and now also with BRD8, in tumors of this type. In all rearrangements of PHF1, including the present one, a recurrent theme is that the entire coding part of PHF1 constitutes the 3' end of the fusion. BRD8 (bromodomain containing 8) encodes a protein which is involved in regulation of protein acetylation and/or histone acetyl transferase activity. All the genetic fusions identified so far in ESS appear to recombine genes involved in transcriptional regulation, that is, polycomb group complex-mediated and aberrant methylation/acetylation genes. This adds to the likelihood that the new BRD8-PHF1 shares the same pathogenetic mechanism as the other ESS-specific rearrangements.