Search Results (59)

The epigenome and nuclear architectural mechanisms that regulate neuronal activity-induced transcriptional responses in cortical neurons remain incompletely understood. Previously, we have shown that the chromatin organizer SATB2 and the inner nuclear membrane protein LEMD2 form a chromatin tether at the nuclear lamina, and that activity-induced transcription is impaired in both Satb2 and Lemd2 loss-of-function models. Interaction of SATB2 and LEMD2 with subunits of the ESCRT-III complex indicates that the ESCRT-III complex could serve as an activity-dependent, dynamic component of this tether. Here, we study the activity-dependent subcellular localization and function of the ESCRT-III components CHMP7 and CHMP4B in primary cortical neurons. We find that increased neuronal activity correlates with the accumulation of co-localized CHMP7 and CHMP4B foci at the nuclear envelope. shRNA-mediated Chmp7 knockdown causes a reduction in the expression of activity-regulated genes and genes with highly specialized functions in synaptic organization and trans-synaptic signaling. Furthermore, the observed similarity in the global transcriptome responses in Satb2, Lemd2, and Chmp7 loss-of-function models points toward a previously unrecognized role of the SATB2–LEMD2–CHMP7 tether in linking chromatin architecture and nuclear envelope plasticity to activity-dependent gene regulation. Full article

Triplexes (TRX) are a class of flipons that can form due to the interaction of RNA with B-DNA. While many proteins have been proposed to bind triplexes, structural models of these interactions do not exist. Here, I present AlphaFold V3 (AF3) models that reveal interactions between the high-mobility group protein B1 (HMGB1), HNRNPU (SAF-A), TP53, ARGONAUTE (AGO), and REL domain proteins. The TRXs result from the sequence-specific docking of RNAs to DNA via Hoogsteen base pairing. The RNA and DNA strands in apolar TRX are oriented in the opposite 5′ to 3′ direction, while copolar TRX have RNA and DNA strands pointing in the same 5′ to 3′ direction. TRXs can incorporate different RNA classes, including long noncoding RNAs (lncRNAs), short RNAs, such as miRNAs, piRNAs, and tRNAs, nascent RNA fragments, and non-canonical base triplets. Many pathways regulated by TRX formation have evolved to constrain retroelements (EREs), which are both an existential threat to the host and a source of genotypic variation. TRXs help set the boundaries of active chromatin, repressing the expression of most EREs, while depending on other flipons to modulate cellular programs. The TRXs help nucleate folding of intrinsically disordered proteins. Full article

SATB2 (special AT-rich binding protein 2) functions as a chromatin-associated epigenetic regulator that modulates gene expression, in part by serving as a transcriptional cofactor. This study assessed whether SATB2 overexpression is sufficient to promote in vitro transformation of human mesothelial cells and whether SATB2 suppression in mesothelioma cancer stem cell (CSC)–enriched populations is associated with altered chemoresistance. SATB2 expression was high in human malignant pleural mesothelioma (MPM) cell lines but absent in Met5A mesothelial cells. Ectopic SATB2 expression in Met5A cells was associated with acquisition of malignant and stem cell–like phenotypes, including increased expression of stem cell markers and pluripotency-associated factors, as well as anchorage-independent growth in soft agar and spheroid formation in suspension culture. In contrast, Met5A cells transduced with an empty vector did not form colonies or mesospheres. SATB2 overexpression in Met5A cells was also associated with increased motility, migration, and invasion, accompanied by induction of epithelial–mesenchymal transition (EMT)–related transcription factors relative to empty vector controls. Conversely, shRNA-mediated SATB2 knockdown in an MPM cell line attenuated proliferation, EMT-associated features, and CSC-like characteristics. Chromatin immunoprecipitation assays identified SATB2 occupancy at promoter regions of Bcl2, XIAP, KLF4, c-Myc, NANOG, and SOX2, consistent with a role in transcriptional regulation of genes linked to transformation, pluripotency, cell survival, proliferation, and EMT. In CSC-enriched cells, SATB2 inhibition was associated with increased sensitivity to cisplatin and pemetrexed, concomitant with reduced OCT4 and SOX2 expression. Collectively, these findings support SATB2 as a candidate therapeutic target in MPM and suggest that SATB2 suppression may enhance chemotherapy response when combined with standard agents. Full article

Background/Objectives: Maternal immune activation (MIA) increases the risk of Autism Spectrum Disorders (ASD). Experimental models demonstrate that maternal exposure to bacterial endotoxin or the viral mimic polyinosinic:polycytidylic acid [poly (I:C)] reliably recapitulates ASD-like behavioral abnormalities in offspring, yet the underlying neurobiological mechanisms linking MIA to altered neurodevelopment remain incompletely understood. Increasing evidence highlights the placenta as a critical mediator in shaping fetal brain development through immunological and hormonal regulation. Likewise, disruption of placental regulatory functions upon MIA may therefore represent a mechanistic pathway. Here, we investigated how alterations in placental cytokine profiles, innate immune cell composition, and endocrine outputs relate to neuroinflammation and neurogenesis in the offspring. Methods: Pregnant mice at gestational day 12.5 received a single intraperitoneal injection of poly (I:C). Placental macrophages, neutrophils, inflammatory cytokines, and nerve growth factor (NGF) expression were examined 72 h later. Neurodevelopmental outcomes, including microglial activity and neurogenic markers, were evaluated in mouse offspring at postnatal day (P) 1 and 6. Results: MIA induced a significant accumulation of monocytes and neutrophils in the placenta, which was associated with elevated levels of a broad spectrum of inflammatory mediators, including Th17-biased proinflammatory cytokines, chemokines, and adhesion proteins, in the placenta and amniotic fluid. In contrast, the placenta-derived NGF levels were significantly reduced. MIA induced strong and sustained microglial activation in the fetal and neonatal brain. This inflammatory milieu was accompanied by disrupted cortical neurogenesis, characterized by a marked increase in Ki67+ neuronal progenitor cells (NPCs) in the subventricular zone (SVZ), overproduction of early-born Tbr1+ neurons at P1, later-born Satb2+ neurons at P6. Conclusions: Collectively, these findings suggest that heightened Th17 inflammatory signaling, coupled with impaired placental endocrine function, contributes to dysregulated cortical neurogenesis in the offspring. Full article

Sjögren’s disease (SjD), which is also known as Sjögren’s syndrome (SS), is a chronic autoimmune disease characterized by dysfunction of exocrine glands, such as the salivary and lacrimal glands, resulting in xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes). Mice in which the SATB1 gene is conditionally deleted in hematopoietic cells (SATB1cKO mice) develop SS as early as 4 weeks of age; however, the etiology of the disease remains to be elucidated. Here, we found that the frequency of abnormally appearing CD4⁺CD8⁺ double positive (DP) T cells in the periphery of SATB1cKO mice was higher in the salivary glands than that in the spleen, suggesting a possible involvement of DP T cells in the pathogenesis of SS in SATB1cKO mice. To investigate the nature of DP T cells, we established DP T cell hybridomas by fusing T cells from the cervical lymph nodes of SATB1cKO mice with the BW5147 thymoma cell line. Among six DP hybridoma clones, the TCRβ gene from five clones exhibited a fetal or immature phenotype. In addition, four out of five clones exhibited upregulated transcription of IL-2 in the salivary glands of T/B cell-deficient RAG2^−/− mice, suggesting that autoreactive T cells were enriched in the DP T cell population of SATB1cKO mice. These results suggest that unusual DP T cells in SATB1cKO mice may be involved in autoimmune pathogenesis in SATB1cKO mice. Full article

Background/Objectives: Although clinicopathologic correlation with integration of clinical and radiographic data is the gold standard in distinguishing primary extramammary Paget disease (EMPD) from secondary EMPD, immunoprofiling of EMPD tumors enables distinction between primary and secondary EMPD. Methods: We evaluated the immunoprofiles of previously published cases in the literature as well as 12 secondary EMPD cases from our archives in order to construct a diagnostic algorithm that enables the distinction between primary and secondary EMPD. Results: Immunoprofiles of 480 primary (published cases) and 132 secondary (120 published cases and 12 institutional cases) EMPD cases were compared. CK7, CK20, CDX2, GATA3, GCDFP15, TRPS1, and SATB2 expression was significantly different in primary EMPD versus colonic secondary EMPD (p < 0.001 for all except SATB2, p = 0.036). CK20, GCDFP15, TRPS1, p63 and uroplakin II/III expression was significantly different in primary EMPD versus urothelial secondary EMPD (p < 0.001). CK7, CDX2, SATB2, GATA3 and p63 expression was significantly different in colonic versus urothelial secondary EMPD. CK20, CDX2, and GCDFP15 expression was significantly different in colonic versus prostatic secondary EMPD. CK20 expression was significantly different in colonic versus prostatic secondary EMPD (p = 0.018). CK20, GCDFP15 and TRPS1 are helpful in the distinction of primary EMPD versus colonic and urothelial secondary EMPD (p < 0.001). Conclusions: We propose that the initial IHC panel should include TRPS1, CK7 and CK20. In TRPS1-negative cases, additional immunostains should be performed: CDX2 and SATB2 for colonic; p63, GATA3 and uroplakin II/III for urothelial; and PSA and NKX3.1 for prostatic secondary EMPD. Full article

Bartholin gland carcinoma (BGC) is a rare malignancy, comprising 3–7% of vulvar cancers and <1% of gynecologic tumors. Due to its low incidence, high-level evidence is lacking, and management is largely extrapolated from vulvar cancer guidelines. This comprehensive narrative review synthesizes current evidence on BGC, emphasizing histotype-specific features, diagnostic criteria, molecular profiling, and treatment strategies. The three most common subtypes are squamous cell carcinoma, adenoid cystic carcinoma (AdCC), and adenocarcinoma. HPV-associated tumors tend to occur in younger women and carry favorable prognoses. Accurate diagnosis requires exclusion of metastases and integration of clinical, imaging, and immunohistochemical data, including p16/HPV for squamous tumors, MYB/MYBL1 fusions for AdCC, and CK20/CDX2/SATB2 for intestinal-type adenocarcinoma. Approximately 50% of cases are diagnosed at an advanced stage due to misclassification as benign cysts or abscesses. Nodal metastasis occurs in >40% of cases, with histotype influencing prognosis. Adenocarcinoma and node-positive disease independently predict worse survival. Treatment hinges on complete surgical excision with 2–3 mm margins, bilateral groin evaluation, and histology-tailored adjuvant therapy. Emerging data support the use of immune checkpoint inhibitors in squamous BGC and targeted agents (e.g., mTOR/CDK4/6 inhibitors) in adenocarcinoma. We propose a practical molecular testing algorithm and highlight the urgent need for prospective, multinational collaboration to establish BGC-specific guidelines. Full article

Background: Medulloblastoma is an aggressive pediatric brain tumor characterized by marked molecular heterogeneity, which significantly impacts prognosis. The low frequency of genomic mutations in medulloblastoma suggests that alternative mechanisms, such as epigenetic regulation, may play a critical role in its pathogenesis. Methods: Using the EpiFactors database, we investigated the expression of epigenetic regulators in two independent RNA sequencing cohorts [Pediatric Brain Tumor Atlas (PBTA) and Williamson], stratified by molecular subgroups and clinical outcomes. We further analyzed expression heterogeneity at the single-cell level in malignant medulloblastoma cells using single-cell RNA sequencing. Results: Members of the SWI/SNF superfamily were dysregulated across all four molecular subtypes of medulloblastoma. Subtype-specific alterations were also observed: the acetyltransferase complex was shared between Group 3 (with SMARCD3 as a potential marker) and Group 4 (with RBM24 as a potential marker); SWR1, β-catenin/TCF, and protein–DNA complexes were specifically enriched in SHH-MB (with EYA1 and SATB2 as SHH markers); and RSC-type, PRC1, DNA polymerase complexes, and X-chromosome-related factors were enriched in WNT-MB (with FOXA1 and PIWIL4 as WNT markers). An epigenetic score (epi-score), linked to RNA metabolism and S-adenosyl-L-methionine pathways, was developed and identified as an independent adverse prognostic factor. High epi-scores were associated with proliferative, stem-like SHH malignant cells (characterized by G2/M phase, low pseudotime, and high entropy), exhibiting alterations in RNA splicing, DNA recombination, and nuclear division. Conclusions: Expression heterogeneity of epigenetic regulators is closely associated with molecular subgroups and clinical outcomes in medulloblastoma. These findings highlight the role of epigenetic dysregulation in RNA metabolism and tumor progression, particularly in SHH-driven proliferative cells. Full article

Background: SATB2-associated syndrome (SAS), also known as Glass syndrome, is a neurodevelopmental disorder (NDD) characterized by intellectual disability, developmental delay, absent or limited speech, and distinctive craniofacial and dental anomalies. It is caused by autosomal dominant pathogenic variants in the SATB2 gene, which plays a crucial role in brain, dental, and jaw development. Due to its variable phenotype, clinical diagnosis can be challenging, necessitating genetic confirmation. Methods: We present six new cases of SAS with SATB2 germline variants identified through next generation sequencing (NGS) technologies, expanding the known genetic and clinical spectrum of the syndrome. Detailed clinical phenotyping was performed for all patients. Results: Our cohort exhibits a broad range of clinical manifestations consistent with SAS, encompassing severe intellectual disability, profound speech delay, various palatal and dental abnormalities. We report the oldest adult patient (56 years old) carrying an in-frame duplication, and a pediatric patient with a missense variant who presented a significant reduction in visual acuity, likely of neurological or cortical origin, in the absence of ophthalmological abnormalities. SATB2 variants include three missenses, two in-frame deletion/duplication and one frameshift variant, several of which are novel and classified as likely pathogenic or pathogenic according to ACMG guidelines. Conclusions: This report provides new clinical and genetic insights into the landscape of SAS. Our findings confirm the phenotypic heterogeneity of SAS and highlight the critical role of comprehensive genetic testing for accurate diagnosis in NDD patients. Full article

Molecular research for genetic variants underlying body weight (BW) provides crucial information for this important selected trait when developing productive poultry breeds, lines and crosses. We searched for molecular markers—single nucleotide polymorphisms (SNPs)—and candidate genes associated with this trait in 240 F₂ resource population Japanese quails (Coturnix japonica). This population was produced by crossing two breeds with contrasting growth phenotypes, i.e., Japanese (with lower growth) and Texas White (with higher growth). The birds were genotyped using the genotyping-by-sequencing method followed by a genome-wide association study (GWAS). Using 74,387 SNPs, GWAS resulted in 142 significant SNPs and 42 candidate genes associated with BW at the age of 1, 14, 28, 35, 42, 49 and 56 days. Hereby, 25 SNPs simultaneously associated with BW at more than one age were established that colocalized with nine prioritized candidate genes (PCGs), including ITM2B, SLC35F3, ADAM33, UNC79, LEPR, RPP14, MVK, ASTN2, and ZBTB16. Twelve PCGs were identified in the regions of two or more significant SNPs, including MARCHF6, EGFR, ADGRL3, ADAM33, NPC2, LTBP2, ZC2HC1C, SATB2, ASTN2, ZBTB16, ADAR, and LGR6. These SNPs and PCGs can serve as molecular genetic markers for the genomic selection of quails with desirable BW phenotypes to enhance growth rates and meat productivity. Full article

Osteosarcoma (OS) and extraskeletal osteosarcoma (EOS) in dogs exhibit histological similarities but differ in anatomical origin, which poses a challenge to diagnostic accuracy. We adopted a marker-first strategy to enhance molecular classification by selecting RUNX2, KPNA2, and SATB2, three validated immunohistochemical (IHC) markers, as primary targets. Bioinformatic screening identified the miR-30 family as the only miRNA group predicted to coordinately regulate RUNX2, KPNA2, and SATB2, justifying its prioritization for expression analysis. RT-qPCR on FFPE tissues from 14 OS, 19 EOS, and 10 healthy controls revealed that miR-30a was significantly downregulated in OS and inversely correlated with RUNX2 nuclear expression, confirmed by IHC. MiR-30e also showed high diagnostic accuracy, while miR-30b and miR-30c distinguished EOS from OS. Non-seed interaction modeling (i.e., outside the canonical “seed” region, spanning nucleotides 2–8 of the miRNA) suggested divergent regulatory affinities within the PI3K/AKT/RUNX2 axis among miR-30 family members. MiR-30a and miR-30e exhibited the highest diagnostic power (LR⁺ 7.7 and 6.8, respectively), supporting their role as biomarkers. These results highlight a miR–30–centered regulatory axis with relevance for diagnosis and molecular stratification of canine osteogenic tumors. Full article

Acute myeloid leukemia (AML) is a malignant hematological tumor with a high prevalence in elderly people, and circular RNA (circRNA) plays an important role in age-related diseases. Induction of cancer cell senescence is a highly promising therapeutic strategy; however, the presence of senescence-associated circRNAs in AML remains to be elucidated. Here, we show that the expression patterns of circRNAs differed between elderly AML patients and healthy volunteers. circSATB1 was significantly overexpressed in elderly patients and AML cells. Knockdown of circSATB1 resulted in the inhibition of proliferation and arrest of the cell cycle in the G0/G1 phase; no effect on apoptosis or DNA integrity was observed, and precocious cellular senescence was promoted, characterized by no change in telomere length. Database analysis revealed that there may be two miRNA and nine RNA-binding proteins (RBPs) involved in regulating the cellular functions of circSATB1. Our observations uncover circSATB1-orchestrated cell senescence in AML, which provides clues for finding more modest therapeutic targets for AML. Full article

Special AT-rich sequence-binding protein 2 (SATB2), as a nuclear matrix-associated protein and transcription factor engaged in chromatin remodeling and the regulation of gene expression, plays an important role in growth and development processes. SATB2 has been shown to have tissue-specific expression, also related to some cancers, including colorectal cancer (CRC). The aim of this study was to compare SATB2 gene expression in tumor and matched non-involved colorectal tissues obtained from CRC patients, and to investigate its association with clinicopathological and demographic parameters, as well as patients’ overall survival. SATB2 mRNA levels in the tested tissues were assessed by quantitative polymerase chain reaction, while SATB2 protein expression was determined by immunohistochemistry. We found that the average levels of both SATB2 mRNA and protein were significantly lower in tumor specimens than in matched non-involved colon tissues. Moreover, SATB2 immunoreactivity was associated with patients’ sex, tumor localization, and grade of differentiation. Lower immunoreactivity of SATB2 protein was noted in high-grade tumors, in women, and in tumors located in the cecum, ascending, and transverse colon. However, the results of the present study did not show an association between SATB2 expression levels and patients’ overall survival. Our findings indicate the involvement of impaired SATB2 expression, significantly reduced in high-grading tumors, in the pathogenesis of CRC, while its sex- and localization-specificity should be further elucidated. Full article

Giant cell tumor of bone (GCTb), formerly also known as osteoclastoma, is a pathological entity that in veterinary medicine is still undefined and, probably, underdiagnosed. In humans, GCTb is recognized as a primary benign bone tumor, locally aggressive, with high local recurrence rates, with controversial histogenesis that can rarely progress or present as a malignant form. In pets, this tumor is still considered rare, though the possibility of underdiagnosis is significant. Hence, the aim of the present study is to provide a histological and immunohistochemical characterization of a small case series of presumptive feline GCTb, comparing our results to the data reported for the human counterpart. Searching our archive, we found, from 2010 to 2023, only three diagnosed cases of GCTb from domestic cats (felis catus). After diagnosis revision, the samples were submitted to immunohistochemistry for Iba1, TRAP, SATB2, RUNX2, RANK, karyopherin α2 (KPNA-2), and osteocalcin. Ki-67 index was also evaluated. Results showed that the multinucleated giant cells were positive for Iba1, TRAP, and RANK, accounting for their osteoclastic origin. On the other side, mononuclear cells were mostly positive for osteoblast markers such as RUNX2, SATB2, and KPNA-2, whereas tumor-associated macrophages showed positivity for Iba1. Hence, results on the cell types characterizing the feline GCTb were comparable to those described in the human form of the tumor. Currently, diagnostic criteria for GCTBs in cats and, in domestic animals more broadly, are still lacking. This study provides valuable data into the immunohistochemical characteristics of the cell populations in feline GCTBs, enhancing veterinarians’ and pathologists’ knowledge for its diagnosis, ultimately improving patient care. Larger case series, complete with follow-up information, molecular analyses for specific mutations, and imaging of both tumors and patients, are needed to improve identification and achieve greater sensitivity in diagnosing this unique tumor. Full article

Infantile Fibrosarcoma is a malignant tumor of fibroblastic origin, typically found in early childhood, locally aggressive, and characterized by molecular alterations that activate tyrosine kinase signaling, primarily the ETV6::NTRK3 fusion. In recent years, a series of fusions different from the classic one have been described, including NTRK1, RAF1, and BRAF. In this paper, we present a case of IFS with a novel EVI5::BRAF fusion. We observed a spindle cell neoplasm growing in intertwined fascicles within a fibrous stroma, without the formation of an immature osteoid matrix. Weak and focal immunoreactivity for S100 was observed. SATB2 exhibited diffuse and intense staining, with focal expression of osteonectin and negativity for caldesmon, Smooth Muscle Actin, desmin, GFAP, SOX10, MelanA, panTRK, and HMB45. The Ki67 index was 7%, and the tumor harbored an EVI5::BRAF genetic fusion. To the best of our knowledge, the EVI5::BRAF fusion has not yet been described in BRAF fusions in IFS. Nevertheless, further studies are needed to define the prognostic features of these emerging BRAF sarcomas, along with new anti-BRAF therapeutic approaches. Full article