Chromosome fusion Dotaz Zobrazit nápovědu
The small genus Ricotia (nine species, Brassicaceae) is confined to the eastern Mediterranean. By comparative chromosome painting and a dated multi-gene chloroplast phylogeny, we reconstructed the origin and subsequent evolution of Ricotia. The ancestral Ricotia genome originated through hybridization between two older genomes with n = 7 and n = 8 chromosomes, respectively, on the Turkish mainland during the Early Miocene (c. 17.8 million years ago, Ma). Since then, the allotetraploid (n = 15) genome has been altered by two independent descending dysploidies (DD) to n = 14 in Ricotia aucheri and the Tenuifolia clade (2 spp.). By the Late Miocene (c. 10 Ma), the latter clade started to evolve in the most diverse Ricotia core clade (6 spp.), the process preceded by a DD event to n = 13. It is noteworthy that this dysploidy was mediated by a unique chromosomal rearrangement, merging together the same two chromosomes as were merged during the origin of a fusion chromosome within the paternal n = 7 genome c. 20 Ma. This shows that within a time period of c. 8 Myr genome evolution can repeat itself and that structurally very similar chromosomes may originate repeatedly from the same ancestral chromosomes by different pathways (end-to-end translocation versus nested chromosome insertion).
- MeSH
- Brassicaceae klasifikace genetika MeSH
- chromozomální aberace MeSH
- chromozomy rostlin * MeSH
- fylogeneze MeSH
- genom rostlinný MeSH
- hybridizace genetická * MeSH
- karyotypizace MeSH
- malování chromozomů MeSH
- molekulární evoluce * MeSH
- ploidie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Turecko MeSH
- MeSH
- akutní lymfatická leukemie * genetika MeSH
- amplifikace genu MeSH
- bcr-abl fúzové proteiny * genetika MeSH
- filadelfský chromozom * MeSH
- hybridizace in situ fluorescenční MeSH
- karyotypizace MeSH
- lidé MeSH
- lidské chromozomy, pár 1 ultrastruktura MeSH
- lidské chromozomy, pár 13 ultrastruktura MeSH
- lidské chromozomy, pár 2 ultrastruktura MeSH
- lidské chromozomy, pár 4 ultrastruktura MeSH
- lidské chromozomy, pár 7 ultrastruktura MeSH
- lidské chromozomy, pár 9 * genetika ultrastruktura MeSH
- předškolní dítě MeSH
- translokace genetická * MeSH
- Check Tag
- lidé MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
BACKGROUND: The TMPRSS2-ERG gene fusion is one of the most widely spread chromosomal rearrangements in carcinomas. Since its discovery, a number of studies have examined its diagnostic, prognostic and therapeutic implications for prostate cancer where suitable biomarkers are still lacking. The publication data are inconsistent. The aim of this review was to critically evaluate the current clinical impact of this gene fusion. METHODS: The PubMed online database was used to search relevant reviews and original articles. RESULTS: Although the TMPRSS2-ERG gene fusion appears to be a suitable diagnostic biomarker, the prognostic implications of this gene fusion are still unclear. Several new strategies for therapeutically targeting ETS fusions and their modulators have been identified and are currently being investigated. CONCLUSION: Due to the heterogeneity of prostate cancer, the combination of several biomarkers is necessary to accurately assess the presence of prostate cancer, predict its potential clinical outcome and decide on appropriate therapy (e.g. PARP inhibitors).
Synovial sarcoma (SS) is a rare soft-tissue tumor that affects children and young adults. It is characterized by chromosomal translocation t(X;18)(p11.2;q11.2), which results in the fusion of the gene SYT on chromosome 18 with SSX genes on chromosome X. Heterogeneity within SS fusion junctions is rare. We report a case of a 9-year-old boy with a high-grade spindle cell sarcoma. Reverse transcriptase-polymerase chain reaction revealed a characteristic translocation of SSs. However, this sarcoma showed a longer-than-expected PCR product after gel electrophoresis. Direct sequencing of the product disclosed a novel SYT/SSX1 fusion transcript. Detection of fusion transcripts is useful for diagnostics of SS. In each case, when considering this diagnosis on the morphologic grounds an attempt to analyze the translocation using PCR should be made, including the recognition of its uncommon variants.
- MeSH
- chromozomální aberace MeSH
- dítě MeSH
- DNA primery MeSH
- fatální výsledek MeSH
- financování organizované MeSH
- fúzní onkogenní proteiny genetika MeSH
- kombinovaná terapie MeSH
- lidé MeSH
- lokální recidiva nádoru patologie terapie MeSH
- molekulární sekvence - údaje MeSH
- nádory měkkých tkání genetika patologie terapie MeSH
- nádory plic genetika sekundární terapie MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- protokoly antitumorózní kombinované chemoterapie terapeutické užití MeSH
- radioterapie MeSH
- sekvence nukleotidů MeSH
- synoviom genetika sekundární terapie MeSH
- transplantace hematopoetických kmenových buněk MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
The karyotypic changes in malignant turner cells are unevenly distributed throughout the human genome. Modern cancer cytogenetics showed that different chromosomal bands are preferentially involved in rearrangements in different neoplasms and specific aberrations were identified. Due to the availability of bone marrow cells first insights were done into pathogenesis of hematologic malignancies and were accompanied by elucidation of the role of chromosomal translocations and deletions. Deletions result very often in loss of a tumor suppressor genes whereas specific translocations and inversions lead to the two principal consequences: 1. new fusion gene encoding chimeric protein is created-mostly in myeloid disorders, 2. gene for the immunoglobulin or T-cell receptor is moved near to the proto-oncogene and enhaces its activity - mostly for lymphoid disorders. All three above mentioned rearrangements were later on proved in solid tumors as well. The breakpoints of many translocations specific for different hematologic and solid tumors have been cloned and serve as molecular markers for diagnosis. Cytogenetic analyses are part of the routine workout of the patients. A variety of molecular techniques are now available for wide genome screening of alterations in copy number, structure and expression of genes and DNA sequences. Molecular cytogenetics has special methods: fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), spectral karyotyping (SKY) and multicolor FISH (mFISH). Except for the basic research of human neoplasias all these methods are used routinely to monitor the effect of the treatment and follow the residual tumor cells after chemotherapy and/or bone marrow transplantation.
We report cytogenetic and molecular genetic analysis of a pediatric tumor positive for the CIC-DUX4 fusion. The tumor belongs to a rare, diagnostically challenging subgroup of undifferentiated small round cell sarcomas. A balanced t(4;19)(q35;q13.1-2) was identified by G-banding, as a sole cytogenetic finding. The translocation was also identified by the M-FISH technique. After RT-PCR, the tumor sample was positive for the CIC-DUX4 fusion. The PCR product contains a novel, so far unreported variant of the CIC-DUX4 fusion transcript, with a fusion of the exon 20 from the CIC gene and the exon 1 from the DUX4 gene.
- MeSH
- fatální výsledek MeSH
- fúzní onkogenní proteiny genetika MeSH
- lidé MeSH
- mladiství MeSH
- nádory měkkých tkání genetika patologie MeSH
- sarkom genetika patologie MeSH
- translokace genetická * MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Akútna myeloidná leukémia (AML) je značne heterogénny podtyp leukémie, ktorý predstavuje 25 % všetkých detských leukémií. Prítomnosťou genetických mutácií v kmeňových krvotvorných/progenitorových bunkách produkuje kostná dreň veľké množstvo abnormálnych nediferencovaných leukocytov (blastov), čo výrazne narúša správnu diferenciáciu buniek. AML je indukovaná dvomi zásahmi. Chromozomálna translokácia počas hematopoézy vnútromaternicového vývoja predstavuje prvý zásah. Tak vzniknú preleukemické fúzne gény (PFG), ktoré sa môžu neskôr transformovať druhým zásahom (bodová genetická mutácia - delécia, inzercia...) na funkčný malígny klon. Medzi charakteristické fúzne gény AML patria napríklad AML1-ETO, PML‐RARA či MLL‐AF9, ktoré následne produkujú hybridné proteíny so zmenenou funkciou. Viaceré štúdie poukazujú na to, že tieto PFG sú považované za dôležitý prognostický nástroj pri hodnotení ochorení. Zatiaľ čo výskyt PFG charakteristických pre akútnu lymfoblastickú leukémiu (ALL) je relatívne dobre preskúmaný a odhadoval sa na 1 až 5 % v pupočníkovej krvi zdravých novorodencov, PFG relevantné pre AML stále nie sú dostatočne objasnené.
Acute myeloid leukemia (AML) is a highly heterogeneous subtype of leukemia, accounting for 25 % of childhood leukemias. By the presence of genetic mutations in hematopoietic/ progenitor stem cells, the bone marrow produces a large number of abnormal undifferentiated leukocytes (blasts), which significantly impairs the proper differentiation of cells. AML is induced by two interventions. Chromosomal translocation during hematopoiesis of intrauterine development is the first intervention. This creates preleukemic fusion genes (PFG), which can later be transformed by a second intervention (point genetic mutation - deletion, insertion ...) into a functional malignant clone. Characteristic AML fusion genes include AML1-ETO, PML-RARA or MLL-AF9, which in turn produce hybrid proteins with altered function. Several studies suggest that these PFGs are considered an important prognostic tool in disease assessment. While the incidence of PFG characteristic of acute lymphoblastic leukemia (ALL) has been relatively well studied by several research groups and has been estimated at 1 to 5% in the umbilical cord blood of healthy neonates, PFG relevant to AML are still not sufficiently clarified.
- MeSH
- akutní myeloidní leukemie * diagnóza genetika MeSH
- alfa receptor kyseliny retinové genetika MeSH
- fúzní onkogenní proteiny * genetika MeSH
- lidé MeSH
- protein PEBP2A2 genetika MeSH
- protein promyelocytické leukemie genetika MeSH
- protoonkogenní protein MLL genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Edible banana cultivars are diploid, triploid, or tetraploid hybrids, which originated by natural cross hybridization between subspecies of diploid Musa acuminata, or between M. acuminata and diploid Musa balbisiana. The participation of two other wild diploid species Musa schizocarpa and Musa textilis was also indicated by molecular studies. The fusion of gametes with structurally different chromosome sets may give rise to progenies with structural chromosome heterozygosity and reduced fertility due to aberrant chromosome pairing and unbalanced chromosome segregation. Only a few translocations have been classified on the genomic level so far, and a comprehensive molecular cytogenetic characterization of cultivars and species of the family Musaceae is still lacking. Fluorescence in situ hybridization (FISH) with chromosome-arm-specific oligo painting probes was used for comparative karyotype analysis in a set of wild Musa species and edible banana clones. The results revealed large differences in chromosome structure, discriminating individual accessions. These results permitted the identification of putative progenitors of cultivated clones and clarified the genomic constitution and evolution of aneuploid banana clones, which seem to be common among the polyploid banana accessions. New insights into the chromosome organization and structural chromosome changes will be a valuable asset in breeding programs, particularly in the selection of appropriate parents for cross hybridization.
- MeSH
- banánovník genetika růst a vývoj MeSH
- chromozomy rostlin genetika MeSH
- diploidie MeSH
- karyotyp MeSH
- malování chromozomů metody MeSH
- molekulární evoluce MeSH
- šlechtění rostlin MeSH
- tetraploidie MeSH
- translokace genetická MeSH
- triploidie MeSH
- zemědělské plodiny genetika růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Cílená terapie představuje v současné době jednu z možných léčebných strategií u plicních nádorů. Její vysoká účinnost spočívá ve specifické inhibici cílové struktury, která je abnormálně aktivovaná v nádorové buňce a hraje klíčovou roli v onkogenezi. EML4-ALK fúzní gen, který byl poprvé popsán před pěti lety u pacientů s adenokarcinomem plic, má prokazatelně onkogenní potenciál, a je proto vhodným kandidátem pro cílenou léčbu. Tato přestavba vzniká v důsledku paracentrické inverze na krátkém raménku chromozomu 2 a vyskytuje se u 3–5 % pacientů s nemalobuněčným karcinomem plic. Dále bylo identifikováno několik dalších genů, které mohou do fúze s genem ALK vstupovat: TGF, KIF5B a KLC1. Cílená inhibice konstitutivně aktivované ALK kinázy zprostředkovaná crizotinibem přinesla u pacientů pozitivních na přestavbu ALK genu výraznou léčebnou odpověď (57 %) s minimální toxicitou. Nicméně nedávno byla popsána ztráta odpovědi na léčbu crizotinibem v důsledku vzniku rezistentních mutací (C1156Y a L1196M) v kinázové doméně fúzního proteinu. Tím se otevírá prostor pro nové, vysoce specifické inhibitory, které budou schopné překonat rezistenci mutovaného EML4-ALK. Při výběru vhodných pacientů pro cílenou terapii hraje nezastupitelnou roli molekulární diagnostika, která nabízí pro detekci přestaveb genu ALK několik různých metodik. S identifikací nových genetických změn asociovaných se vznikem nádoru a vývojem nových molekulárních inhibitorů se léčba onkologických pacientů stále více posouvá k individualizované terapii.
Targeted therapy currently represents one of possible treatment strategies for lung cancer. High efficacy is achieved by specific inhibition of the target which is abnormally activated in a tumor cell and plays a key role in oncogenesis. EML4-ALK fusion gene, first described five years ago in patients with lung adenocarcinoma, undoubtedly has oncogenic potential and represents a promising candidate for targeted therapy. EML4-ALK fusion occurs due to paracentric inversion in the short arm of chromosome 2 and is detected in 3–5% of patients with non-small cell lung cancer. Moreover, additional fusion partners of ALK gene have been identified: TGF, KIF5B and KLC1. Targeted inhibition of constitutively activated ALK kinase mediated by crizotinib in patients positive for ALK gene rearrangements resulted in remarkable treatment response (57%) with minimal toxicity. Nevertheless, loss of response during crizotinib treatment was reported recently due to development of two resistant mutations (C1156Y and L1196M) within the kinase domain of the fusion protein. Therefore, novel, highly specific inhibitors able to overcome resistance of mutated EML4-ALK are needed. Molecular diagnostics plays an essential role in selection of suitable patients for targeted therapy and offers various methods for detection of ALK gene rearrangements. Identification of tumor-associated genetic changes together with development of novel molecular inhibitors shifts the treatment of oncologic patients towards individualized therapy.
- Klíčová slova
- molekulární diagnostika, crizotinib, inhibitory proteinkináz, molekulární cílená terapie, anaplastic lymphoma kinase,
- MeSH
- chromozomální inverze genetika MeSH
- cílená molekulární terapie * metody MeSH
- diagnostické techniky molekulární metody MeSH
- fúzní onkogenní proteiny genetika metabolismus MeSH
- hybridizace in situ fluorescenční metody MeSH
- imunohistochemie MeSH
- individualizovaná medicína MeSH
- inhibitory proteinkinas farmakologie škodlivé účinky terapeutické užití MeSH
- lidé MeSH
- nádorová transformace buněk genetika patologie MeSH
- nádorové biomarkery analýza genetika MeSH
- nádory plic farmakoterapie genetika patologie MeSH
- nemalobuněčný karcinom plic * farmakoterapie genetika patologie MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody MeSH
- proteiny asociované s mikrotubuly * genetika metabolismus MeSH
- proteiny buněčného cyklu genetika metabolismus MeSH
- pyrazoly farmakologie škodlivé účinky terapeutické užití MeSH
- pyridiny farmakologie škodlivé účinky terapeutické užití MeSH
- translokace genetická MeSH
- určení vhodnosti pacienta metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH