Canalicular tumors of the salivary glands have recently emerged as an entity characterized by distinct morphology and recurrent HMGA2 gene rearrangement. In this study, we analyzed 40 cases intending to elucidate their features further. The monophasic or biphasic tumors exhibited a growth pattern of interconnected anastomosing trabeculae and canaliculi, accompanied by a classical pleomorphic adenoma in one-third of the cases. Invasive growth into surrounding adipose tissue was revealed in one case which was, therefore, diagnosed as epithelial-myoepithelial carcinoma. Although the tumor cells uniformly expressed HMGA2 protein in all cases, cytokeratin 7, S100 protein, and SOX10 displayed either diffuse positivity or highlighted the luminal and abluminal cell populations, respectively. Areas with morphological oncocytoid change and AR-immunopositivity of luminal cells were seen in 13/14 (93%) of tested biphasic cases. HMGA2 rearrangement was detected by RNA-sequencing in 30 cases. The most common alteration was an HMGA1::WIF1 fusion, but several novel or rare fusion partners were identified, including ARID2 , FHIT , MSRB3 and its antisense variant MSRB3-AS1 , IFNG-AS1 , and the long intergenic region LINC02389 . In addition, FISH revealed HGMA2 break-apart in the remaining 10 cases where targeted sequencing failed to detect any alteration or where RNA sequencing could not be performed. Notably, the loss of the 3'-untranslated region of HMGA2 emerges as the common denominator for the described rearrangements, possibly disrupting its negative regulation by small regulatory RNAs. Awareness of this lesion ensures appropriate diagnosis and clinical management, especially with regard to the possibility of malignant transformation described in this and previous studies.

• Klíčová slova
• apocrine transformation, canalicular adenoma-like subtype of pleomorphic adenoma, epithelial-myoepithelial carcinoma, salivary glands,
• MeSH
• dospělí MeSH
• fenotyp MeSH
• genetická predispozice k nemoci MeSH
• genová přestavba * MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory slinných žláz * genetika   patologie   chemie   MeSH
• pleomorfní adenom * genetika   patologie   chemie   MeSH
• protein HMGA2 * genetika   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• HMGA2 protein, human MeSH Prohlížeč
• nádorové biomarkery * MeSH
• protein HMGA2 * MeSH

Penile squamous cell carcinoma (pSCC) represents an uncommon malignancy characterized by stagnant mortality, psychosexual distress, and a highly variable prognosis. Currently, the World Health Organization distinguishes between human papillomavirus (HPV)-related and HPV-independent pSCC. Recently, there has been an evolving line of research documenting the enrichment of HPV-independent pSCC with a high tumor mutational burden (TMB) and programmed death ligand-1 expression, as well as clusters of genes associated with HPV status. In this study, we conducted comprehensive next-generation sequencing DNA profiling of 146 pSCC samples using a panel consisting of 355 genes associated with tumors. This profiling was correlated with immunohistochemical markers and prognostic clinical data. A survival analysis of recurrent genomic events (found in ≥10 cases) was performed. TP53, CDKN2A, ATM, EPHA7, POT1, CHEK1, GRIN2A, and EGFR alterations were associated with significantly shortened overall survival in univariate and multivariate analysis. HPV positivity, diagnosed through both p16 immunohistochemistry and HPV DNA analysis, displayed no impact on survival but was associated with high-grade, lymphatic invasion, programmed death ligand-1 negativity/weak expression, and low TMB. FAT1, TP53, CDKN2A, CASP8, and HRAS were more often mutated in HPV-independent pSCC. In contrast, HPV-associated pSCCs were enriched by EPHA7, ATM, GRIN2A, and CHEK1 mutations. PIK3CA, FAT1, FBXW7, and KMT2D mutations were associated with high TMB. NOTCH1, TP53, CDKN2A, POT1, KMT2D, ATM, CHEK1, EPHA3, and EGFR alterations were related to adverse clinicopathologic signs, such as advanced stage, high tumor budding, and lymphovascular invasion. We detected 160 alterations with potential treatment implications, with 21.2% of samples showing alterations in the homologous recombination repair pathway. To the best of our knowledge, this study describes the largest cohort of pSCC with complex molecular pathologic, clinical, and prognostic analysis correlating with prognosis.

• Klíčová slova
• human papillomavirus, next-generation sequencing, penile, squamous cell carcinoma, tumor mutational burden,
• MeSH
• ATM protein genetika   MeSH
• dospělí MeSH
• erbB receptory genetika   MeSH
• infekce papilomavirem MeSH
• inhibitor p16 cyklin-dependentní kinasy genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádorový supresorový protein p53 genetika   MeSH
• nádory penisu * genetika   mortalita   patologie   virologie   MeSH
• prognóza MeSH
• proteiny vázající telomery MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• shelterinový komplex MeSH
• spinocelulární karcinom * genetika   mortalita   patologie   virologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ATM protein, human MeSH Prohlížeč
• ATM protein MeSH
• CDKN2A protein, human MeSH Prohlížeč
• EGFR protein, human MeSH Prohlížeč
• erbB receptory MeSH
• inhibitor p16 cyklin-dependentní kinasy MeSH
• nádorové biomarkery * MeSH
• nádorový supresorový protein p53 MeSH
• POT1 protein, human MeSH Prohlížeč
• proteiny vázající telomery MeSH
• shelterinový komplex MeSH
• TP53 protein, human MeSH Prohlížeč

BACKGROUND AND PURPOSE: CNS embryonal tumor with pleomorphic adenoma gene-like 1 (PLAGL1)/pleomorphic adenoma gene-like 2 (PLAGL2) amplification (ET, PLAGL) is a newly identified, highly malignant pediatric tumor. Systematic MRI descriptions of ET, PLAGL are currently lacking. MATERIALS AND METHODS: MRI data from 19 treatment-naïve patients with confirmed ET, PLAGL were analyzed. Evaluation focused on anatomic involvement, tumor localization, MRI signal characteristics, DWI behavior, and the presence of necrosis and hemorrhage. Descriptive statistics (median, interquartile range, percentage) were assessed. RESULTS: Ten patients had PLAGL1 and nine had PLAGL2 amplifications. The solid components of the tumors were often multinodular with heterogeneous enhancement (mild to intermediate in 47% and intermediate to strong in 47% of cases). Nonsolid components included cysts in 47% and necrosis in 84% of the cases. The tumors showed heterogeneous T2WI hyper- and isointensity (74%), relatively little diffusion restriction (ADC values less than contralateral normal-appearing WM in 36% of cases with available DWI), and tendencies toward hemorrhage/calcification (42%). No reliable distinction was found between PLAGL1- and PLAGL2-amplified tumors or compared with other embryonal CNS tumors. CONCLUSIONS: The study contributes to understanding the imaging characteristics of ET, PLAGL. It underscores the need for collaboration in studying rare pediatric tumors and advocates the use of harmonized imaging protocols for better characterization.

• MeSH
• amplifikace genu MeSH
• dítě MeSH
• DNA vazebné proteiny * genetika   MeSH
• gen SMARCB1 MeSH
• germinální a embryonální nádory * genetika   patologie   MeSH
• kojenec MeSH
• lidé MeSH
• magnetická rezonanční tomografie * metody   MeSH
• mladiství MeSH
• nádory mozku * genetika   patologie   MeSH
• předškolní dítě MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• transkripční faktory * genetika   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA vazebné proteiny * MeSH
• gen SMARCB1 MeSH
• PLAG1 protein, human MeSH Prohlížeč
• SMARCB1 protein, human MeSH Prohlížeč
• transkripční faktory * MeSH

Massive bleeding causes approximately 50% of deaths in patients with major trauma. Most patients die within 6 h of injury, which is preventable in at least 10% of cases. For these patients, early activation of the massive transfusion protocol (MTP) is a critical survival factor. With severe trauma, high-mobility group box 1 (HMGB-1, i.e., amphoterin) is released into the blood, and its levels correlate with the development of a systemic inflammatory response, traumatic coagulopathy, and fibrinolysis. Previous work has shown that higher levels of HMGB-1 are associated with a higher use of red blood cell transfusions. We conducted a retrospective analysis of previous prospective single-center study to assess the value of admission HMGB-1 levels in predicting activation of MTP in the emergency department. From July 11, 2019, to April 23, 2022, a total of 104 consecutive adult patients with severe trauma (injury severity score > 16) were enrolled. A blood sample was taken at admission, and HMGB-1 was measured. MTP activation in the emergency department was recorded in the study documentation. The total amount of blood products and fibrinogen administered to patients within 6 h of admission was monitored. Among those patients with massive bleeding requiring MTP activation, we found significantly higher levels of HMGB-1 compared to patients without MTP activation (median [interquartile range]: 84.3 µg/L [34.2-145.9] vs. 21.1 µg/L [15.7-30.4]; p < 0.001). HMGB-1 level showed good performance in predicting MTP activation, with an area under the receiver operating characteristic curve of 0.84 (95% CI 0.75-0.93) and a cut-off value of 30.55 µg/L. HMGB-1 levels correlated significantly with the number of red blood cell units (rs [95% CI] 0.46 [0.28-0.61]; p < 0.001), units of fresh frozen plasma (rs 0.46 [0.27-0.61]; p < 0.001), platelets (rs 0.48 [0.30-0.62]; p < 0.001), and fibrinogen (rs 0.48 [0.32-0.62]; p < 0.001) administered in the first 6 h after hospital admission. Admission HMGB-1 levels reliably predict severe bleeding requiring MTP activation in the emergency department and correlate with the amount of blood products and fibrinogen administered during the first 6 h of hemorrhagic shock resuscitation.Trial registration: NCT03986736. Registration date: June 4, 2019.

• Klíčová slova
• Bleeding, HMGB-1, Major trauma, Massive transfusion protocol,
• MeSH
• biologické markery krev   MeSH
• dospělí MeSH
• krevní transfuze * metody   MeSH
• krvácení * terapie   krev   etiologie   diagnóza   MeSH
• lidé středního věku MeSH
• lidé MeSH
• protein HMGB1 * krev   MeSH
• rány a poranění * komplikace   krev   terapie   MeSH
• retrospektivní studie MeSH
• ROC křivka MeSH
• senioři MeSH
• skóre závažnosti úrazu MeSH
• urgentní služby nemocnice MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• Názvy látek
• biologické markery MeSH
• HMGB1 protein, human MeSH Prohlížeč
• protein HMGB1 * MeSH

Myoepithelial neoplasms of the skin and soft tissue still represent a confusing and somewhat controversial field in pathology as it appears that this category includes several different entities. However, recent studies have suggested that both apocrine mixed tumors (AMT) and cutaneous myoepitheliomas (CM) harbor identical chromosomal rearrangements involving the PLAG1 gene and hence may represent a morphological spectrum. The aim of the present study was to share our institutional experience with these tumors and specifically focus on studying their immunohistochemical and molecular features to further assess their relatedness. Eleven cases of AMT and 7 cases of CM were collected and analyzed using immunohistochemistry (IHC), PLAG1 FISH, and Archer FusionPlex assay. There were 14 male and 4 female patients with ages ranging from 26 to 85 years (median 55.8 years, mean 58.5 years). AMTs were mainly located in the head and neck (n = 10), while CMs were mainly located in the acral sites (n = 5). PLAG1 IHC was diffusely strongly positive in 14/17 (82%) cases, whereas a single case of AMT diffusely expressed HMGA2. Both tumor groups showed PLAG1 gene fusions which were detected in 6/13 analyzable samples (AMT, n = 4 and CM, n = 2), and included TRPS1::PLAG1 (n = 3), NDRG1::PLAG1 (n = 1), CTNNB1::PLAG1 (n = 1) and a novel PXDNL::PLAG1 fusion (n = 1). The remaining 5 cases were negative, 5 were not analyzable and the single case positive for HMGA2 by IHC revealed a potential HMGA2 gene rearrangement. The cases were further studied by FISH, with 12/17 cases showing PLAG1 gene rearrangement (AMT, n = 8 and CM, n = 4). Altogether, 14/18 cases showed PLAG1 gene rearrangement by at least one of the methods. PLAG1 immunohistochemistry had a 92% specificity and sensitivity. Our study provided additional data to suggest that AMT and CM share overlapping morphological and immunohistochemical features as well as molecular background characterized by PLAG1 gene fusions and thus represent a morphological spectrum. In addition, we identified a novel PXDNL::PLAG1 fusion and suggested that rare cases may harbor HMGA2 gene alterations which seem to be mutually exclusive with PLAG1 gene fusions. The relatedness of these tumors to salivary gland myoepithelial neoplasms and distinctness from eccrine mixed tumors and other skin and soft tissue myoepithelial neoplasms with EWSR1/FUS fusions is discussed.

• Klíčová slova
• HMGA2, PLAG1, Apocrine mixed tumors, Cutaneous myoepitheliomas, Myoepithelial neoplasm, Targeted RNA sequencing,
• MeSH
• apokrinní žlázy * patologie   MeSH
• DNA vazebné proteiny * genetika   MeSH
• dospělí MeSH
• genová přestavba * MeSH
• hybridizace in situ fluorescenční MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• myoepiteliální nádor * genetika   patologie   chemie   MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory kůže * genetika   patologie   chemie   MeSH
• nádory potních žláz * genetika   patologie   MeSH
• protein HMGA2 * genetika   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• DNA vazebné proteiny * MeSH
• HMGA2 protein, human MeSH Prohlížeč
• nádorové biomarkery * MeSH
• PLAG1 protein, human MeSH Prohlížeč
• protein HMGA2 * MeSH

BACKGROUNDS: SWI/SNF complexes represent a family of multi-subunit chromatin remodelers that are affected by alterations in >20% of human tumors. While mutations of SWI/SNF genes are relatively uncommon in prostate cancer (PCa), the literature suggests that deregulation of various subunits plays a role in prostate tumorigenesis. To assess SWI/SNF functions in a clinical context, we studied the mutually exclusive, paralogue accessory subunits SMARCD1, SMARCD2, and SMARCD3 that are included in every known complex and are sought to confer specificity. METHODS: Performing immunohistochemistry (IHC), the protein levels of the SMARCD family members were measured using a tissue microarray (TMA) comprising malignant samples and matching healthy tissue of non-metastatic PCa patients (n = 168). Moreover, IHC was performed in castration-resistant tumors (n = 9) and lymph node metastases (n = 22). To assess their potential role as molecular biomarkers, SMARCD1 and SMARCD3 protein levels were correlated with clinical parameters such as T stage, Gleason score, biochemical recurrence, and progression-free survival. RESULTS: SMARCD1 protein levels in non-metastatic primary tumors, lymph node metastases, and castration-resistant samples were significantly higher than in benign tissues. Likewise, SMARCD3 protein expression was elevated in tumor tissue and especially lymph node metastases compared to benign samples. While SMARCD1 levels in primary tumors did not exhibit significant associations with any of the tested clinical parameters, SMARCD3 exhibited an inverse correlation with pre-operative PSA levels. Moreover, low SMARCD3 expression was associated with progression to metastasis. CONCLUSIONS: In congruence with previous literature, our results implicate that both SMARCD1 and SMARCD3 may exhibit relevant functions in the context of prostate tumorigenesis. Moreover, our approach suggests a potential role of SMARCD3 as a novel prognostic marker in clinically non-metastatic PCa.

• Klíčová slova
• SMARCD1, SMARCD3, SWI/SNF complex, prognostic marker, prostate cancer,
• MeSH
• chromozomální proteiny, nehistonové * genetika   metabolismus   MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokální recidiva nádoru patologie   metabolismus   genetika   MeSH
• lymfatické metastázy MeSH
• nádorové biomarkery * genetika   metabolismus   MeSH
• nádory prostaty rezistentní na kastraci patologie   genetika   metabolismus   MeSH
• nádory prostaty * patologie   metabolismus   genetika   MeSH
• prognóza MeSH
• senioři MeSH
• stupeň nádoru MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chromozomální proteiny, nehistonové * MeSH
• nádorové biomarkery * MeSH
• SMARCD1 protein, human MeSH Prohlížeč
• transkripční faktory MeSH

Carcinoma ex pleomorphic adenoma (CXPA) is an aggressive epithelial and/or myoepithelial neoplasm that arises in association with a pleomorphic adenoma (PA). Its etiopathogenesis remains poorly understood, but it is believed that the development of this tumor is due to the accumulation of genetic, protein, metabolic, and epigenetic alterations in a PA. A retrospective review of the Salivary Gland Tumor Registry in Pilsen yielded 84 CXPA, namely 25/84 salivary duct carcinoma (SDC), 15/84 myoepithelial carcinoma (MC), 1/84 epithelial-myoepithelial carcinoma (EMC), and 1/84 adenoid cystic carcinoma (AdCC). All 84 CXPA cases were analyzed by next-generation sequencing (NGS) and/or fluorescence in situ hybridization (FISH). Forty-three tumors originally diagnosed as CXPA (43/84, 51.2%) showed some molecular alteration. Fusion transcripts were identified in 12/16 (75%) CXPA, including LIFR::PLAG1, CTNNB1::PLAG1, FGFR1::PLAG1 , and a novel fusion, HMGA2::LINC02389 . Most of the fusions were confirmed by FISH using PLAG1 (6/11) and HMGA2 (1/1) gene break probes. Split signals indicating gene break were identified by FISH for PLAG1 (12/17), HMGA2 (3/4), EWSR1 (7/22), and MYB (2/7). Concerning pathogenic mutations, only CXPA with epithelial differentiation (SDC) presented these alterations, including HRAS mutation (2/4), TP53 (1/4), PTEN (1/4), and ATK1 (1/4). In addition, amplifications in ERBB2 (17/35), MDM2 (1/4), and EWSR1 (1/7) were detected. A novel finding was the discovery of an HMGA2::LINC02389 fusion in 1 patient with EMC ex-PA. The present results indicate that molecular profiling of CXPA with myoepithelial differentiation (MC) tends to reveal chromosomal fusion events, whereas CXPA with epithelial differentiation (SDC) tends to have a higher frequency of pathogenic mutations and gene amplifications.

• Klíčová slova
• HMGA2, PLAG1, carcinoma ex pleomorphic adenoma, gene fusion, molecular, pathogenic mutations, salivary glands,
• MeSH
• dospělí MeSH
• fúze genů * MeSH
• genetická predispozice k nemoci MeSH
• hybridizace in situ fluorescenční MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové biomarkery * genetika   MeSH
• nádory slinných žláz * genetika   patologie   MeSH
• pleomorfní adenom * genetika   patologie   MeSH
• protein HMGA2 * genetika   MeSH
• registrace MeSH
• retrospektivní studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• HMGA2 protein, human MeSH Prohlížeč
• nádorové biomarkery * MeSH
• protein HMGA2 * MeSH

The RNA content is crucial for the formation of nuclear compartments, such as nuclear speckles and nucleoli. Phosphatidylinositol 4,5-bisphosphate (PIP2) is found in nuclear speckles, nucleoli, and nuclear lipid islets and is involved in RNA polymerase I/II transcription. Intriguingly, the nuclear localization of PIP2 was also shown to be RNA-dependent. We therefore investigated whether PIP2 and RNA cooperate in the establishment of nuclear architecture. In this study, we unveiled the RNA-dependent PIP2-associated (RDPA) nuclear proteome in human cells by mass spectrometry. We found that intrinsically disordered regions (IDRs) with polybasic PIP2-binding K/R motifs are prevalent features of RDPA proteins. Moreover, these IDRs of RDPA proteins exhibit enrichment for phosphorylation, acetylation, and ubiquitination sites. Our results show for the first time that the RDPA protein Bromodomain-containing protein 4 (BRD4) associates with PIP2 in the RNA-dependent manner via electrostatic interactions, and that altered PIP2 levels affect the number of nuclear foci of BRD4 protein. Thus, we propose that PIP2 spatiotemporally orchestrates nuclear processes through association with RNA and RDPA proteins and affects their ability to form foci presumably via phase separation. This suggests the pivotal role of PIP2 in the establishment of a functional nuclear architecture competent for gene expression.

• MeSH
• buněčné jádro * metabolismus   genetika   MeSH
• fosfatidylinositol-4,5-difosfát * metabolismus   MeSH
• fosforylace MeSH
• jaderné proteiny * metabolismus   genetika   MeSH
• lidé MeSH
• proteiny buněčného cyklu metabolismus   genetika   MeSH
• proteiny obsahující bromodoménu MeSH
• RNA metabolismus   genetika   MeSH
• transkripční faktory * metabolismus   genetika   MeSH
• vazba proteinů MeSH
• vnitřně neuspořádané proteiny * metabolismus   genetika   chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BRD4 protein, human MeSH Prohlížeč
• fosfatidylinositol-4,5-difosfát * MeSH
• jaderné proteiny * MeSH
• proteiny buněčného cyklu MeSH
• proteiny obsahující bromodoménu MeSH
• RNA MeSH
• transkripční faktory * MeSH
• vnitřně neuspořádané proteiny * MeSH

The establishment of long-lasting immunity against pathogens is facilitated by the germinal center (GC) reaction, during which B cells increase their antibody affinity and differentiate into antibody-secreting cells (ASC) and memory cells. These events involve modifications in chromatin packaging that orchestrate the profound restructuring of gene expression networks that determine cell fate. While several chromatin remodelers were implicated in lymphocyte functions, less is known about SMARCA5. Here, using ribosomal pull-down for analyzing translated genes in GC B cells, coupled with functional experiments in mice, we identified SMARCA5 as a key chromatin remodeler in B cells. While the naive B cell compartment remained unaffected following conditional depletion of Smarca5, effective proliferation during B cell activation, immunoglobulin class switching, and as a result GC formation and ASC differentiation were impaired. Single-cell multiomic sequencing analyses revealed that SMARCA5 is crucial for facilitating the transcriptional modifications and genomic accessibility of genes that support B cell activation and differentiation. These findings offer novel insights into the functions of SMARCA5, which can be targeted in various human pathologies.

• MeSH
• adenosintrifosfatasy MeSH
• aktivace lymfocytů imunologie   MeSH
• B-lymfocyty * metabolismus   imunologie   MeSH
• buněčná diferenciace * MeSH
• chromozomální proteiny, nehistonové * metabolismus   genetika   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• přesmyk imunoglobulinových tříd genetika   MeSH
• restrukturace chromatinu * MeSH
• zárodečné centrum lymfatické uzliny * imunologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenosintrifosfatasy MeSH
• chromozomální proteiny, nehistonové * MeSH
• Smarca5 protein, mouse MeSH Prohlížeč

SF3B1 mutations are recurrent in chronic lymphocytic leukemia (CLL), particularly enriched in clinically aggressive stereotyped subset #2. To investigate their impact, we conducted RNA-sequencing of 18 SF3B1MUT and 17 SF3B1WT subset #2 cases and identified 80 significant alternative splicing events (ASEs). Notable ASEs concerned exon inclusion in the non-canonical BAF (ncBAF) chromatin remodeling complex subunit, BRD9, and splice variants in eight additional ncBAF complex interactors. Long-read RNA-sequencing confirmed the presence of splice variants, and extended analysis of 139 CLL cases corroborated their association with SF3B1 mutations. Overexpression of SF3B1K700E induced exon inclusion in BRD9, resulting in a novel splice isoform with an alternative C-terminus. Protein interactome analysis of the BRD9 splice isoform revealed augmented ncBAF complex interaction, while exhibiting decreased binding of auxiliary proteins, including SPEN, BRCA2, and CHD9. Additionally, integrative multi-omics analysis identified a ncBAF complex-bound gene quartet on chromosome 1 with higher expression levels and more accessible chromatin in SF3B1MUT CLL. Finally, Cancer Dependency Map analysis and BRD9 inhibition displayed BRD9 dependency and sensitivity in cell lines and primary CLL cells. In conclusion, spliceosome dysregulation caused by SF3B1 mutations leads to multiple ASEs and an altered ncBAF complex interactome, highlighting a novel pathobiological mechanism in SF3B1MUT CLL.

• MeSH
• alternativní sestřih MeSH
• chronická lymfatická leukemie * genetika   patologie   metabolismus   MeSH
• fosfoproteiny * genetika   metabolismus   MeSH
• lidé MeSH
• mutace * MeSH
• proteiny obsahující bromodoménu MeSH
• restrukturace chromatinu * MeSH
• sestřihové faktory * genetika   metabolismus   MeSH
• spliceozomy * metabolismus   genetika   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BRD9 protein, human MeSH Prohlížeč
• fosfoproteiny * MeSH
• proteiny obsahující bromodoménu MeSH
• sestřihové faktory * MeSH
• SF3B1 protein, human MeSH Prohlížeč
• transkripční faktory MeSH