Aneuploidy Research Articles

Energy‑stress‑mediated activation of AMPK sensitizes MPS1 kinase inhibition in triple‑negative breast cancer.

Monopolar spindle 1 kinase (Mps1, also known as TTK protein kinase) inhibitors exert marked anticancer effects against triple‑negative breast cancer (TNBC) by causing genomic instability and cell death. As aneuploid cells are vulnerable to compounds that induce energy stress through adenosine monophosphate‑activated protein kinase (AMPK) activation, the synergistic effect of Mps1/TTK inhibition and AMPK activation was investigated in the present study. The combined effects of CFI‑402257, an Mps1/TTK inhibitor, and AICAR, an AMPK agonist, were evaluated in terms of cytotoxicity, cell‑cycle distribution, and in vivo xenograft models. Additional molecular mechanistic studies were conducted to elucidate the mechanisms underlying apoptosis and autophagic cell death. The combination of CFI‑402257 and AICAR showed selective cytotoxicity in a TNBC cell line. The formation of polyploid cells was attenuated, and apoptosis was increased by the combination treatment, which also induced autophagy through dual inhibition of the PI3K/Akt/mTOR and mitogen‑activated protein kinase (MAPK) signaling pathways. Additionally, the combination therapy showed strongly improved efficacy in comparison with CFI‑402257 and AICAR monotherapy in the MDA‑MB‑231 xenograft model. The present study suggested that the combination of CFI‑402257 and AICAR is a promising therapeutic strategy for TNBC.

67. An undiagnosed chronic myeloid leukemia (CML) with p190 BCR::ABL1 transcript, an extra Philadelphia chromosome, and IKARO

67. An undiagnosed chronic myeloid leukemia (CML) with p190 BCR::ABL1 transcript, an extra Philadelphia chromosome, and IKARO

Investigating the role of RNA-binding protein Ssd1 in aneuploidy tolerance through network analysis.

RNA-binding proteins (RBPs) play critical cellular roles by mediating various stages of RNA life cycles. Ssd1, an RBP with pleiotropic effects, has been implicated in aneuploidy tolerance in Saccharomyces cerevisiae but its mechanistic role remains unclear. Here we used a network-based approach to inform on Ssd1's role in aneuploidy tolerance, by identifying and experimentally perturbing a network of RBPs that share mRNA targets with Ssd1. We identified RBPs whose bound mRNA targets significantly overlap with Ssd1 targets. For 14 identified RBPs, we then used a genetic approach to generate all combinations of genotypes for euploid and aneuploid yeast with an extra copy of chromosome XII, with and without SSD1 and/or the RBP of interest. Deletion of 10 RBPs either exacerbated or alleviated the sensitivity of wild-type and/or ssd1 Δ cells to chromosome XII duplication, in several cases indicating genetic interactions with SSD1 in the context of aneuploidy. We integrated these findings with results from a global over-expression screen that identified genes whose duplication complements ssd1 Δ aneuploid sensitivity. The resulting network points to a sub-group of proteins with shared roles in translational repression and p-body formation, implicating these functions in aneuploidy tolerance. Our results reveal a role for new RBPs in aneuploidy tolerance and support a model in which Ssd1 mitigates translation-related stresses in aneuploid cells.

HIF1A contributes to the survival of aneuploid and mosaic pre-implantation embryos.

Human fertility is suboptimal, partly due to error-prone divisions in early cleavage-stages that result in aneuploidy. Most human pre-implantation are mosaics of euploid and aneuploid cells, however, mosaic embryos with a low proportion of aneuploid cells have a similar likelihood of developing to term as fully euploid embryos. How embryos manage aneuploidy during development is poorly understood. This knowledge is crucial for improving fertility treatments and reducing developmental defects. To explore these mechanisms, we established a new mouse model of chromosome mosaicism to study the fate of aneuploid cells during pre-implantation development. We previously used the Mps1 inhibitor reversine to generate aneuploidy in embryos. Here, we found that treatment with the more specific Mps1 inhibitor AZ3146 induced chromosome segregation defects in pre-implantation embryos, similar to reversine. However, AZ3146-treated embryos showed a higher developmental potential than reversine-treated embryos. Unlike reversine-treated embryos, AZ3146-treated embryos exhibited transient upregulation of Hypoxia Inducible-Factor-1A (HIF1A) and lacked p53 upregulation. Pre-implantation embryos develop in a hypoxic environment in vivo, and hypoxia exposure in vitro reduced DNA damage in response to Mps1 inhibition and increased the proportion of euploid cells in the mosaic epiblast. Inhibiting HIF1A in mosaic embryos also decreased the proportion of aneuploid cells in mosaic embryos. Our work illuminates potential strategies to improve the developmental potential of mosaic embryos.

Elimination of the extra chromosome of Dup15q syndrome iPSCs for cellular and molecular investigation

Chromosome 15q11.2–13.1 duplication (Dup15q) syndrome is one of the most common autism spectrum disorders (ASDs) associated with copy number variants (CNVs). For the analysis of CNV-relevant pathological cellular phenotypes, a CNV-corrected isogenic cell line is useful for excluding the influence of genetic background. Here, we devised a strategy to remove the isodicentric chromosome 15 by inserting a puro-ΔTK selection cassette into the extra chromosome using the CRISPR-Cas9 system, followed by a subsequent two-step drug selection. A series of assays, including qPCR-based copy number analysis and karyotype analysis, confirmed the elimination of the extra chromosome. Furthermore, cerebral organoids were generated from the parental Dup15q iPSCs and their isogenic iPSCs. scRNA-seq analysis revealed the alteration of expression levels in ion-channel-related genes and synapse-related genes in glutamatergic and GABAergic neurons in Dup15q organoids, respectively. The established isogenic cell line is a valuable resource for unraveling cellular and molecular alterations associated with Dup15q syndrome.

Simple aneuploidy evades p53 surveillance and promotes niche factor-independent growth in human intestinal organoids.

Aneuploidy is nearly ubiquitous in tumor genomes, but the role of aneuploidy in the early stages of cancer evolution remains unclear. Here, by inducing heterogeneous aneuploidy in non-transformed human colon organoids (colonoids), we investigated how the effects of aneuploidy on cell growth and differentiation may promote malignant transformation. Previous work implicated p53 activation as a downstream response to aneuploidy induction. We found that simple aneuploidy, characterized by 1-3 gained or lost chromosomes, resulted in little or modest p53 activation and cell cycle arrest when compared with more complex aneuploid cells. Single-cell RNA sequencing analysis revealed that the degree of p53 activation was strongly correlated with karyotype complexity. Single-cell tracking showed that cells could continue to divide despite the observation of one to a few lagging chromosomes. Unexpectedly, colonoids with simple aneuploidy exhibited impaired differentiation after niche factor withdrawal. These findings demonstrate that simple aneuploid cells can escape p53 surveillance and may contribute to niche factor-independent growth of cancer-initiating colon stem cells.

Biphasic co-detection of melanoma aneuploid tumor cells and tumor endothelial cells in guidance of specifying the field cancerized surgical excision margin and administering immunotherapy

An optimum safety excision margin (EM) delineated by precise demarcation of field cancerization along with reliable biomarkers that enable predicting and timely evaluating patients’ response to immunotherapy significantly impact effective management of melanoma. In this study, optimized biphasic “immunofluorescence staining integrated with fluorescence insitu hybridization” (iFISH) was conducted along the diagnosis-metastasis-treatment-cellular MRD axis to longitudinally co-detect a full spectrum of intact CD31− aneuploid tumor cells (TCs), CD31+ aneuploid tumor endothelial cells (TECs), viable and necrotic circulating TCs (CTCs) and circulating TECs (CTECs) expressing PD-L1, Ki67, p16 and Vimentin in unsliced specimens of the resected primary tumor, EM, dissected sentinel lymph nodes (SLNs) and peripheral blood in an early-stage melanoma patient. Numerous PD-L1+ aneuploid TCs and TECs were detected at the conventional safety EM (2 cm), quantitatively indicating the existence of a field cancerized EM for the first time. Contrary to highly heterogeneous PD-L1 expression and degrees of Chr8 aneuploidy in TCs and TECs in the primary lesions as well as CTCs and CTECs in peripheral blood, almost all TCs and TECs in SLNs and EM were homogeneously PD-L1+ haploid cells. Dynamic monitoring and cellular MRD assessment revealed that, in contrast to PD-L1+ CTCs being responsive to the immune checkpoint inhibitor (ICI-anti-PD-1), multiploid (≥pentasomy 8) PD-L1+ and Ki67+ CTECs were respectively resistant to ICI-sensitized T cells. In therapeutically stressed lymphatic and hematogenous metastatic cascades, stratified phenotypic and karyotypic profiling of iFISH tissue and liquid biopsied TCs, TECs, CTCs and CTECs in future large-cohort studies will enable appropriate re-specification of the optimal safety EM and distribution mapping of in-depth characterized, subcategorized target cells to help illustrate their metastatic relevance, ultimately improving risk stratification and clinical intervention of tumor progression, metastases, therapy resistance and cancer relapse.

Congenital syndromic Chiari-like malformation (CSCM) in Holstein cattle: towards unravelling of possible genetic causes

BackgroundChiari malformation type II (CMII) was originally reported in humans as a rare disorder characterized by the downward herniation of the hindbrain and towering cerebellum. The congenital brain malformation is usually accompanied by spina bifida, a congenital spinal anomaly resulting from incomplete closure of the dorsal aspect of the spinal neural tube, and occasionally by other lesions. A similar disorder has been reported in several animal species, including cattle, particularly as a congenital syndrome. A cause of congenital syndromic Chiari-like malformation (CSCM) in cattle has not been reported to date. We collected a series of 14 CSCM-affected Holstein calves (13 purebred, one Red Danish Dairy F1 cross) and performed whole-genome sequencing (WGS). WGS was performed on 33 cattle, including eight cases with parents (trio-based; group 1), three cases with one parent (group 2), and three single cases (solo-based; group 3).ResultsSequencing-based genome-wide association study of the 13 Holstein calves with CSCM and 166 controls revealed no significantly associated genome region. Assuming a single Holstein breed-specific recessive allele, no region of shared homozygosity was detected suggesting heterogeneity. Subsequent filtering for protein-changing variants that were only homozygous in the genomes of the individual cases allowed the identification of two missense variants affecting different genes, SHC4 in case 4 in group 1 and WDR45B in case 13 in group 3. Furthermore, these two variants were only observed in Holstein cattle when querying WGS data of > 5,100 animals. Alternatively, potential de novo mutational events were assessed in each case. Filtering for heterozygous private protein-changing variants identified one DYNC1H1 frameshift variant as a candidate causal dominant acting allele in case 12 in group 3. Finally, the presence of larger structural DNA variants and chromosomal abnormalities was investigated in all cases. Depth of coverage analysis revealed two different partial monosomies of chromosome 2 segments in cases 1 and 7 in group 1 and a trisomy of chromosome 12 in the WDR45B homozygous case 13 in group 3.ConclusionsThis study presents for the first time a detailed genomic evaluation of CSCM in Holstein cattle and suggests an unexpected genetic and allelic heterogeneity considering the mode of inheritance, as well as the type of variant. For the first time, we propose candidate causal variants that may explain bovine CSCM in a certain proportion of affected calves. We present cattle as a large animal model for human CMII and propose new genes and genomic variants as possible causes for related diseases in both animals and humans.

P-567 Is mosaic embryo transfer a valid alternative for patients lacking euploid embryos? a multicentric study from Argentina

Abstract Study question How does low-level mosaicism embryo transfer affect reproductive outcomes, including pregnancy rates and live birth success, compared to transfers involving euploid embryos? Summary answer Most mosaic embryo transfers do not affect reproductive outcomes, as live birth rates appear to be similar to those observed with euploid embryos. What is known already Preimplantation genetic testing (PGT) is used to identify embryonic genetic abnormalities and, ideally, select euploid embryos for intrauterine transfer, to improve clinical IVF outcomes. Chromosomal mosaicism is defined as the presence of two or more different chromosomal cell lines within an embryo. Numerous sources describe the proportion of mosaic embryos ranging from 4 to 22%. Several publications report that mosaic embryo transfer can lead to successful pregnancies and healthy deliveries, albeit at a lower frequency and with higher rates of pregnancy loss compared to euploid embryos. However, the impact of mosaicism on IVF outcomes remains a matter of controversy. Study design, size, duration Observational and retrospective multi-center study analyzed 6241 embryos from 1218 patients, across 4 IVF centers, who underwent PGT between 2016 and 2023 in a single genetics laboratory. Embryos were categorized as euploid, aneuploid, or mosaic. Patients in group A (n = 894) were transferred an euploid embryo, while in group B (n = 55), a low-grade mosaic embryo, defined as those having less than 40% (2016-2021) or 50% (2021-2023) aneuploid cells, was transferred. Participants/materials, setting, methods The embryos were biopsied and vitrified for later transfer. Blastocyst biopsy DNA was amplified using the SurePlex kit, processed with the VeriSeq kit (Vitrolife), and sequenced on a MiSeq platform. The results were analyzed using BlueFuse-Multi software. Mosaic embryo transfers were conducted only in the absence of a euploid embryo, following genetic counseling. beta-hCG levels >25 IU were considered positive, and clinical pregnancy was confirmed through ultrasound visualization of the gestational sac with heartbeat. Main results and the role of chance Among the analyzed embryos, the proportion of euploid was 46.2% (n = 2883), while mosaic embryos accounted for 19.3% (n = 1207), with 69.5% classified as low-grade and 30.5% as high-grade. Aneuploid embryos comprised 31.3% (n = 1954), and results could not be obtained for 3.2% (n = 197). Fifty-five low-grade mosaic embryos were transferred, including 19 with complete chromosomal mosaicism, 34 with segmental mosaicism, and 2 cases with 2 chromosomes involved in the mosaicism. The positive beta-hCG rate post-transfer was 50.3% for Group A, compared to 49.1% for Group B. Clinical pregnancy rates were 36.9% and 36.4%, respectively. Regarding live births, in Group A 328 (36.7%) children were born, and in Group B, 16 (29.1%), with 2 ongoing pregnancies. Conversely, pregnancy losses in Group B (9.1%) were higher compared to the euploid group (2.9%). Regarding pregnancy losses, in 3 cases no fetal heartbeats were identified, there was one miscarriage <20 weeks, and one twin gestation was lost after a normal non-invasive prenatal testing. In all cases the newborns were apparently healthy after mosaic embryo transfer, with an average gestational week at birth of 39 (37-41), and an average weight of 3197 (2900-4390) grams. Cesarean section was performed for 15/16 births, and one was born by vaginal delivery. Limitations, reasons for caution The study is limited by its retrospective nature and the small number of samples and mosaics transferred. Prenatal and postnatal tests were not conducted. Furthermore, the health of newborns was evaluated only in the initial months of life. Wider implications of the findings Mosaic embryo transfer is a valid alternative for couples lacking euploid embryos. This multicenter study adds evidence that mosaic embryo transfer does not have a clinically relevant impact on pregnancy and live birth rates, similar to what has been reported by other authors. Trial registration number ‘not applicable’

A healthy live birth after mosaic blastocyst transfer in preimplantation genetic testing for GATA1-related cytopenia combined with HLA matching

BackgroundGATA1-related cytopenia (GRC) is characterized by thrombocytopaenia and/or anaemia ranging from mild to severe. Haematopoietic stem cell transplantation (HSCT) is a healing therapeutic choice for GRC patients. We identified a novel pathogenic variant (GATA1: c.1019delG) in a boy with GATA1-related cytopenia. Then we performed preimplantation genetic testing (PGT) in this GRC family. After a mosaic embryo transfered, a healthy and HLA-compatible with the proband baby was delivered.Case presentationThe proband is a 6-year-old boy who was diagnosed to have transfusion-dependent anaemia since 3 year old. Whole-exome sequencing (WES) showed that the proband has a hemizygous variant c.1019delG in GATA1, which is inherited from his mother. His parents decided to undergo PGT to have a health and HLA-compatible offspring. After whole genome amplification (WGA) of biopsied trophectoderm (TE) cells, next generation sequencing (NGS)-based PGT was preformed to analyse embryos on chromosomal aneuploidy, target mutation and HLA typing. There were 3 embryos HLA-matched to the proband. The genotypes of the 3 embryos were heterozygous variant, hemizygous variant, normal respectively. After a heterozygous, mosaic partial trisomy (chr)16, and HLA-matched embryo transfer, a healthy baby was delivered and whose HSCT is compatible with the proband.ConclusionsNGS-based PGT-HLA is a valuable procedure for the treatment of GATA1-related cytopenia caused by GATA1 variants, or other haematological disorders, oncological and immunological diseases. Furthermore, our study reconfirms that mosaic embryos transfer would bring healthy offspring.

O-271 Two component resolution of mosaic samples in PGT-A: primary template amplification (PTA) and independent analysis using copy-number variation and allelic balance

Abstract Study question How does accurate, unbiased whole genome amplification and tiered, independent, two component analysis impact PGT-A results? Summary answer When compared to previous methods a PGT-A workflow utilizing PTA followed by a CNV and allelic balance-based analysis generated more conclusive results. What is known already Accurate PGT-A results require unbiased error-free whole genome amplification from the trophectoderm biopsy and smart bioinformatics utilities to fully analyze and consider the large complex datasets. PTA generates fewer errors, greater coverage, and reduced allele drop-out offering the best starting point to interpret the genome of each embryo. Current PGT-A platforms leverage either normalized CNV data OR allelic balance at single nucleotide polymorphisms (SNPs), to detect alterations in the embryonic genome. A pipeline leveraging improved amplification technology and consolidated CNV and SNP data, particularly for putative mosaic and segmental mosaic calls, could reduce uncertainty and provide more accurate PGT-A results. Study design, size, duration A retrospective analysis of PGT-A results was undertaken with samples originating from multiple clinics and processed in a single laboratory, from January through December, 2023. Approximately 500 samples were processed simultaneously through two independent PGT-A pipelines. The primary objective was to compare the performance of CNV-only PGT-A with a test leveraging both CNV and SNP data. A secondary objective was to observe the resolution of mosaic embryos. Participants/materials, setting, methods De-identified samples were amplified with PTA and sequenced with both shotgun (coverage-based CNV) and capture (SNP-based)-approaches. Method specific analysis was applied to the resulting data. An initial bioinformatics approach analyzed CNV data only for variations in copy-number along the genome, proposing stretches of aneuploidy or mosaicism. A second, tiered analysis extended this data and incorporated SNP-based allelic balance to evaluate candidate regions and confirm the presence of aneuploidy and/or quantify mosaic levels. Main results and the role of chance Genome-wide read coverage and SNP data confirmed that PTA accurately and completely amplified the genetic material in each sample with broad distribution of informative data and a low allele drop-out rate. High concordance (95%) was observed for euploid and full aneuploid (whole chromosome and segmental) embryos classified with CNV-alone and CNV/SNV combined analysis. SNP data was processed, and B-allele ratios were used to confirm aneuploidies with particular utility in resolving the location of segmental changes. The classification of mosaic samples was altered in the pipeline leveraging both CNV and SNP data. Of 54 mosaic samples tested, 75% remained mosaic after independent consideration of SNP data, ∼15% and 6% of high-level mosaics were resolved to full aneuploid and euploid, respectively, and ∼25% of low-level mosaics reverted to a euploid classification. The deep SNP data produced during targeted sequencing confirmed the altered allele ratio predicted by CNV data and re-confirmed the presence and proportion of aneuploid cells. Mosaic levels were highly correlated in 90% of re-confirmed mosaic samples. This suggests that the classification of these samples as mosaic is precise and accurate and suggests a strong utility for a two component PGT-A pipeline leveraging CNV and SNV data generated from PTA embryos. Limitations, reasons for caution This was a retrospective study with limited sample numbers. Wider implications of the findings The study highlights the strong advantages of a hybrid PGT-A pipeline, leveraging PTA and two component analysis of coverage and allelic balance, particularly to resolve mosaic embryos more accurately. Overall, this could reduce uncertainty and deliver more confident PGT-A results for embryo transfer decision making. Trial registration number not applicable

THERAPEUTIC INTERVENTION AS A KEY AREA IN WORKING WITH A STUDENT WITH DOWN SYNDROME (DS) IN THE CONTEXT OF AN INDIVIDUAL CASE STUDY

ABSTRACT: Aim: analysis of the functioning of an 18-year-old female student with Down syndrome. The analysis is set in the context of the diagnosis and therapeutic-stimulating activities undertaken by the family and the school. Methods: The research used a qualitative strategy. A case study was used. Interview and document analysis techniques were used. The research was undertaken in the spirit of positive psychology, requiring the identification of optimal functioning of people with disabilities and the factors that determine this. Results: The analysis presented in the text shows that the diagnostic processes and processes built on their basis, educational and therapeutic activities determine the possibilities of use potential of an individual with DS. Long-term and systematic work of teachers and specialists, cooperation with the mother does not bring fully satisfactory results. Conclusion: An extra chromosome is a significant obstacle to the development of people with DS on many levels. The interactions of the family environment and school promote more active participation of the individual in society. Diagnostic procedures are a key condition for appropriate therapeutic intervention. Recognizing the profile of each person's characteristics is the discovery of his individual potential. Rehabilitation interventions, planned on the basis of diagnosis and systematically implemented by parents and teachers, can be a real harbinger of improvement in the quality of life of a student with DS. Originality: A holistic case analysis enables insight and understanding of an important educational problem - the determinants and effectiveness of the diagnosis and rehabilitation of a student with DS. As the number of students with learning and behavioral difficulties increases, it seems that the need to promote knowledge on how to undertake therapeutic interventions is still current. Keywords: Down syndrome, student, diagnosis, rehabilitation, therapy, support, school, family.

Effect of Aerobic Exercise on Static & Dynamic Balance in Children with Down Syndrome

Background: Down syndrome, characterized by an extra chromosome 21, affects physical and developmental growth. Children with Down syndrome often exhibit impairments in balance and motor function, necessitating interventions that enhance physical capabilities and overall quality of life. Objective: To evaluate the efficacy of aerobic exercises compared to standard physical therapy in improving static and dynamic balance in children with Down syndrome. Methods: This randomized controlled trial included 20 children aged 5-12 years with Down syndrome, recruited from the Rising Sun Institute of Special Education. Participants were randomly divided into a control group, which received standard physical therapy, and an experimental group, which engaged in aerobic exercise (cycling) three times a week for 30 minutes over an 8-week period. The primary outcomes, static and dynamic balance, were assessed using the Pediatric Balance Scale (PBS) and the 6-Minute Walk Test (6MWT) before and after the intervention. Results: The experimental group showed significant improvements compared to the control group. The mean changes in the Timed Up and Go test were reduced by 3.67 seconds (p < 0.05), the PBS scores increased by 10.23 points (p < 0.05), and the 6MWT distance extended by 66.11 meters (p < 0.05). Conclusion: Aerobic exercise interventions significantly enhance static and dynamic balance in children with Down syndrome, surpassing the effects of standard physical therapy. Incorporating structured aerobic exercises into rehabilitation programs is recommended to optimize developmental outcomes in this population. Keywords: Down Syndrome, Aerobic Exercise, Pediatric Balance Scale, 6-Minute Walk Test, Static Balance, Dynamic Balance, Randomized Controlled Trial.

Abstract PR008: Targeting mechanisms of dosage compensation to selectively kill aneuploid cancer cells

Abstract Aneuploidy is an abnormal chromosome composition and a general hallmark of human cancer. Aneuploidy causes detrimental cellular stresses, but cancer cells evolve to cope with these stresses. Consequently, targeting such mitigation mechanisms is a promising potential therapeutic strategy. As an abnormal dosage of gene products from altered chromosomes can cause RNA and proteotoxic stress, dosage compensation (DC) of imbalanced gene products was reported to mitigate these stresses in aneuploid cells. However, the mechanisms that regulate DC remain elusive. To address these mechanisms, we focused on the role(s) of stress granules (SGs) and RNA binding proteins (RBPs) in aneuploid cancer cells. Our recent study revealed that aneuploid cancer cells preferentially depend on RNA and protein metabolism, and need to attenuate translation in order to cope with proteotoxic stress (Ippolito & Zerbib et al. bioRxiv 2023). In yeast, it has been previously reported that Ssd1, one of the RBPs localized in P-bodies, is indispensable to tolerating aneuploidy stress. Based on these findings, we set out to explore SGs as potential regulators of gene expression in aneuploid cancer cells. As expected, we revealed that SGs emerged in cells under acute aneuploidy stress induced by chromosome mis-segregation. These results imply that SGs are formed in cells during and right after aneuploidization, potentially as a way to mediate DC and ameliorate aneuploidy-induced cellular stress. To gain further insight into RNA regulation in aneuploid cells, we analyzed the essentiality of RBPs across cancer cell lines. We found that the RNA-editing enzyme ADAR, a suppressor of SG formation, is preferentially essential in aneuploid cancer cells. Remarkably, ADAR disruption synergized with acute aneuploidy stress to induce SGs, and ADAR exhibited increased RNA editing activity following chromosome mis-segregation. Our results suggest that SGs and their suppressor ADAR might contribute to ameliorating acute aneuploidy-induced stress. We are currently investigating the target RNAs regulated by SGs and ADAR and examining their functional role(s) in DC, with the goal of uncovering potential synthetic lethalities associated with aneuploidy in cancer cells. Citation Format: Hajime Okada, Eran Sdeor, Miriam Karmon, Erez Levanon, Uri Ben-David. Targeting mechanisms of dosage compensation to selectively kill aneuploid cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr PR008.

Abstract IA015: Identifying and targeting synthetic lethalities of aneuploid (cancer) cells

Abstract Aneuploidy, an imbalanced number of chromosomes or chromosome arms, is a genetic hallmark of cancer cells, yet aneuploidy remains a biological enigma and a missed opportunity for cancer therapy. Aneuploid cells must cope with several types of cellular stresses, potentially creating synthetic lethalities that can be used to target aneuploid cancer cells. Here, I will describe our efforts to identify synthetic lethalities of the aneuploid state (in contrast to synthetic lethalities of specific recurrent aneuploidies. Specifically, I will focus on three recent unpublished studies, where we report that: (1) Aneuploid cells are preferentially sensitive to perturbation of the spindle assembly checkpoint (SAC) and its regulator KIF18A; the expression and activity of CDC20 determine the sensitivity to SAC inhibition. (2) Aneuploid cells depend on MAPK signaling for overcoming aneuploidy-induced DNA damage; targeting MAPK signaling can sensitize aneuploid cells to DNA damage inducing agents and to PARP inhibitors. (3) Aneuploid cells depend on RNA and protein degradation mechanisms to attenuate the cellular consequence of extra chromosomes; this renders aneuploid cells more sensitive to inhibition of nonsense-mediate decay, miRNA-mediated gene silencing, and the proteasome complex. Citation Format: Uri Ben-David. Identifying and targeting synthetic lethalities of aneuploid (cancer) cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr IA015.

Abstract B003: Identification of novel genes that regulate aneuploidy tolerance by attenuating aneuploidy-induced stresses

Abstract Aneuploidy, an imbalanced number of chromosomes or chromosome arms, is the most common genetic aberration in cancer and is associated with a worse prognosis and advanced disease. However, in non-transformed cells, aneuploidy has a substantial fitness cost, leading to cell cycle arrest and cell death. This fitness cost is the result of several cellular stresses associated with aneuploidy, including proteotoxic, metabolic, mitotic and replication stress. Therefore, for aneuploidy to become beneficial, tolerance mechanisms that enable cancer cells to cope with aneuploidy-induced cellular stresses must come into play. Such mechanisms may uncover novel synthetic lethalities of aneuploid cancer cells. To this end, we systematically dissected the cellular mechanisms that facilitate aneuploidy tolerance. We combined large-scale analyses of gene expression, as well as genetic and pharmacological dependency datasets from human tumors, cancer cell lines and non-transformed cells, to identify genes and pathways associated with aneuploidy tolerance. We identified 55 genes associated (with high confidence) with aneuploidy tolerance. Gene set enrichment analysis (GSEA) revealed an enrichment for ribosome biogenesis and translation, DNA repair, replication stress and the p53 pathway. Interestingly, these pathways were all previously implicated with the aforementioned aneuploidy-induced cellular stresses. We plan to conduct a dependency mini-screen to validate the top ‘hits’ from our comprehensive bioinformatic analysis, and to explore the role of validated candidates in conferring aneuploidy tolerance. One of the top ‘hits’ of our exploratory analysis was a novel gene with an unclear cellular function. We experimentally confirmed that this gene was over-expressed in aneuploid cells, across several isogenic systems of matched diploid-aneuploid cell lines. Aneuploidy induction using MPS1 inhibitors led to its significant upregulation, demonstrating that its increased expression is a general feature of aneuploid cells. Mechanistically, we found that the novel gene had a role in regulating chromosome segregation, as its knockdown increased the rate of mitotic aberrations – as well as the sensitivity to mitotic checkpoint inhibition – resulting in increased chromosomal instability. We now study the molecular basis for the effect of this novel gene on aneuploidy tolerance. Specifically, we knocked it down in aneuploid cells, and over-expressed it in diploid cells, and we currently explore how these manipulations affect the above-mentioned aneuploidy tolerance pathways, namely replication stress, ribosome biogenesis, DNA damage repair and tp53 activation. In summary, we revealed a novel gene that is a key regulator of aneuploidy tolerance in cancer cells, likely due to its direct involvement in pathways required for the cellular coping with aneuploidy-induced stresses. Citation Format: Yonatan Eliezer, Adi V Tarrab, Tal Ben-Yishay, Hajime Okada, Tom Winkler, Uri Ben-David. Identification of novel genes that regulate aneuploidy tolerance by attenuating aneuploidy-induced stresses [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr B003.

Effects of Drought Stress on Abscisic Acid Content and Its Related Transcripts in Allium fistulosum—A. cepa Monosomic Addition Lines

Climate change has resulted in an increased demand for Japanese bunching onions (Allium fistulosum L., genomes FF) with drought resistance. A complete set of alien monosomic addition lines of A. fistulosum with extra chromosomes from shallot (A. cepa L. Aggregatum group, AA), represented as FF + 1A–FF + 8A, displays a variety of phenotypes that significantly differ from those of the recipient species. In this study, we investigated the impact of drought stress on abscisic acid (ABA) and its precursor, β-carotene, utilizing this complete set. In addition, we analyzed the expression levels of genes related to ABA biosynthesis, catabolism, and drought stress signal transduction in FF + 1A and FF + 6A, which show characteristic variations in ABA accumulation. A number of unigenes related to ABA were selected through a database using Allium TDB. Under drought conditions, FF + 1A exhibited significantly higher ABA and β-carotene content compared with FF. Additionally, the expression levels of all ABA-related genes in FF + 1A were higher than those in FF. These results indicate that the addition of chromosome 1A from shallot caused the high expression of ABA biosynthesis genes, leading to increased levels of ABA accumulation. Therefore, it is expected that the introduction of alien genes from the shallot will upwardly modify ABA content, which is directly related to stomatal closure, leading to drought stress tolerance in FF.

Prenatal detection of chromosome 7q deletion with duplication: A case report and literature review.

With advances in prenatal diagnostic techniques, chromosomal microdeletions and microduplications have become the focus of prenatal diagnosis. 7q partial monosomy or trisomy due to a deletion or duplication of the 7q end is relatively rare and usually originates from parents carrying a balanced translocation. Noninvasive prenatal screening (NIPT) showed a fetus with partial deletion and duplication of chromosome 7q. It was not possible to determine whether the fetus was normal. Conventional chromosome G-banding and chromosome microarray analysis (CMA) were performed on fetal amniotic fluid samples and parental peripheral blood samples. The pregnant women were given detailed genetic counseling by clinicians. The fetal karyotype was 46, XY on conventional G-banding analysis. The CMA test results showed a deletion of approximately 7.8 Mb in the 7q36.1q36.3 region and a duplication of 6.6Mb in the 7q35q36.1 region. The parents' karyotype analysis and CMA results were normal, indicating a new mutation. CMA molecular diagnostic analysis can effectively detect chromosomal microdeletions or microduplications, clarify the relationship between fetal genotype and clinical phenotype, and provide a reference for prenatal diagnosis of chromosomal microdeletion-duplication syndrome.

Pragmatic Language in Children with Down Syndrom: A Systematic Review

Abstract Background: Down syndrome (SD) is the most common genetic disorder and the easiest to identify. SD or better known as the genetic disorder trisomy, where there is an extra chromosome on chromosome 21. Objectives: Analyzing pragmatic abilities in Down Syndrome children and learning materials in writing scientific research as well as providing additional information regarding pragmatic abilities in Down Syndrome children. Methods: The research carried out is a systematic review research. This research uses data from previous research. A quantitative systematic review combines findings from various independent studies, and produces a statistical summary of those findings (Last, 2001 in Murti, 2018). Results: Down syndrome children show conditions of intellectual problems that are continuous with language problems. Where cognitive abilities are the main capital in communication. Conclusion: Semantic-pragmatic communication abilities create core impairments in the narratives of children with Down syndrome. Pragmatic difficulties and deficits in global executive function when compared with children with other typical development.. Keywords: Pragmatic Language, Dwon syndrome, Systematic review

Molecular cytogenetic screening of sex chromosome abnormalities in young horse populations.

Chromosomal abnormalities occur in the equine population at a rate of approximately 2%. The use of molecular cytogenetic techniques allows a more accurate identification of chromosomal abnormalities, especially those with a low rate of abnormal metaphases, demonstrating that the actual incidence in equine populations is higher. Estimation of the number of carriers of karyotypic abnormalities in a sample from a population of young horses of various breeds, using molecular cytogenetic techniques. Cross-sectional. Venous blood samples were collected from 500 young horses representing 5 breeds (Purebred Arabian, Hucul, Polish primitive horse [Konik], Małopolska, Coldblood, Silesian). Chromosomes and DNA were obtained from blood lymphocytes and evaluated by fluorescence in situ hybridisation (FISH) and PCR, using probes and markers for the sex chromosomes and select autosomes. Nineteen horses, 18 mares and 1 stallion, were diagnosed with different chromosomal abnormalities: 17 cases of mosaic forms of sex chromosome aneuploidies with a very low incidence (0.6%-4.7%), one case of a SRY-negative 64,XY sex reversal mare, and one mare with X-autosome translocation. The percentage of sex chromosomal aberrations was established as 3.8% in the whole population, 6.08% in females and 0.49% in males. Limited sample size, confined to horses from Poland. The rate of sex chromosomal abnormalities we identified was almost double that reported in previous population studies that used classical chromosome staining techniques. FISH allowed the detection of aneuploid cell lines which had a very low incidence. The FISH technique is a faster and more precise method for karyotype examination; however, it is usually focused on only one or two chromosomes while banding karyotyping includes the entire chromosome set.