Fragmented Nuclei Research Articles

The genotoxicity effects and oxidative stress of common volatile and injectable anesthesia drugs on peripheral blood during irradiation of BALB/c mice

IntroductionIonizing radiation (IR) is well-known for its genotoxic and cytotoxic effects. Additionally, anesthesia has been shown to cause various side effects, including genotoxicity. This study aims to evaluate the DNA damage and oxidative stress resulting from exposure to both anesthesia and IR. MethodsSeventy BALB/c male mice were divided into 14 identical groups and anesthetized using three different inhalation anesthetics (isoflurane, sevoflurane, and halothane) and three different injectable anesthetics (propofol, ketamine, and thiopental). We also evaluated combinations of these anesthetic drugs with 1 Gy IR. DNA damage in white blood cells was assessed using the alkaline comet assay at 0, 2, and 24 h after treatment. Additionally, oxidative stress in blood samples was measured 6 h post-treatment. ResultsThe percentage of DNA in the tail and fragmented nuclei after 2 and 24 h was significantly higher in the groups given volatile anesthetics compared to the propofol and thiopental groups (P<0.05). Furthermore, oxidative stress levels were also significantly higher in the volatile anesthetic groups (P<0.05). When combined with IR, the volatile anesthetics and ketamine resulted in increased genotoxicity and significantly higher oxidative stress compared to the group exposed only to IR (P<0.05). In contrast, propofol and thiopental did not lead to a significant increase in genotoxicity or oxidative stress compared to the control group (P>0.07). ConclusionCombining volatile anesthetic drugs and ketamine with 1 Gy irradiation resulted in higher levels of toxic effects and oxidative stress, although this combination did not produce a synergistic effect. Additionally, the combination of propofol and thiopental with IR did not show a significant difference compared to the irradiated-only group in both the alkaline comet and oxidative stress assays.

Purkinje cell-specific deficiency in SEL1L-hrd1 endoplasmic reticulum-associated degradation causes progressive cerebellar ataxia in mice.

Recent studies have identified multiple genetic variants of SEL1L-HRD1 endoplasmic reticulum-associated degradation (ERAD) in humans with neurodevelopmental disorders and locomotor dysfunctions, including ataxia. However, the relevance and importance of SEL1L-HRD1 ERAD in the pathogenesis of ataxia remain unexplored. Here, we showed that SEL1L deficiency in Purkinje cells leads to early-onset progressive cerebellar ataxia with progressive loss of Purkinje cells with age. Mice with Purkinje cell-specific deletion of SEL1L (Sel1LPcp2Cre) exhibited motor dysfunction beginning around 9 weeks of age. Transmission electron microscopy analysis revealed dilated ER and fragmented nuclei in Purkinje cells of adult Sel1LPcp2Cre mice, indicative of altered ER homeostasis and cell death. Finally, loss of Purkinje cells was associated with a secondary neurodegeneration of granular cells, as well as robust activation of astrocytes and proliferation of microglia, in the cerebellums of Sel1LPcp2Cre mice. These data demonstrate the pathophysiological importance of SEL1L-HRD1 ERAD in Purkinje cells in the pathogenesis of cerebellar ataxia.

Investigation of nanoparticle flow characteristics in a pulsed fluidized bed using the DQMOM method with aggregation and fragmentation nucleus

Investigation of nanoparticle flow characteristics in a pulsed fluidized bed using the DQMOM method with aggregation and fragmentation nucleus

Hurst Exponent and Event-by-Event Fluctuations in Relativistic Nucleus–Nucleus Collisions

A joint study of multi-particle pseudo-rapidity correlations and event-by-event fluctuations in the distributions of secondary particles and fragments of the target nucleus and the projectile nucleus was carried out in order to search for correlated clusters of secondary particles. An analysis of the collisions of the sulfur nucleus with photoemulsion nuclei at an energy of 200 A·GeV is presented based on experimental data obtained at the SPS at CERN. The analysis of multi-particle correlations was performed using the Hurst method. A detailed analysis of each individual event showed that in events of complete destruction of a projectile nucleus with a high multiplicity of secondary particles, long-distance multi-particle pseudo-rapidity correlations are observed. The distribution of average pseudo-rapidity in such events differs significantly from others, as it is much narrower, and its average value is noticeably shifted towards lower values &lt;η&gt;.

Resveratrol enhances sensitivity of renal cell carcinoma to tivozanib: An in-vitro study

BackgroundSince tivozanib has many side effects in the treatment of kidney cancer, we decided to use resveratrol as a bioactive molecule with anticancer and antioxidant properties to make tivozanib more effective and also reduce its side effects in kidney cancer cell line. MethodIn this in vitro study, we evaluated the effect of tivozanib, resveratrol and tivozanib- resveratrol combination therapy in ACHN cell line as representatives of human kidney cancer. The assessment includes Hoechst dye staining, scratch-wound assay, 3D spheroid, 2D colony formation assay, flow cytometric analysis of apoptosis and DNA cell cycle, real-time PCR (BAX/BCL2, E-cadherin, Snail, HIF1α, VEGFC and KLK3 genes). ResultTo determine IC50 levels, ACHN cells was exposed to different concentration of tivozanib and resveratrol. Our data indicated that IC50 values for tivozanib (0.5 μM) and resveratrol (30 μM) with MTT in a dose and time-dependent manner. Due to the efficacy of resveratrol in combination with tivozanib, we used 20 μM resveratrol, and 0.25 μM tivozanib instead of 30 μM and 0.25 μM respectively. This data was approved by flow cytometry for ACHN cell line with 38.39, 14.74 and 66.06 percent apoptosis and 8.25, 5.12 and 15.6 percent subG1 for tivozanib, resveratrol and tivozanib-resveratrol combination respectively which was as a consequence of cell cycle arrest at G1/S phase. The treatment also reduced cells’ migration, fragmented nuclei, 3D spheroid and colony formation potentials in analyses. Evaluation of gene expression presented that the effect of the tivozanib and resveratrol combination in ACHN cell lines is completely different during the evaluation of apoptosis genes, BAX, P53 genes and E-Cadherin had significantly increased expression compared to single treatment groups (P < 0.01). Meanwhile, a significant decrease was observed in the expression of VEGFC and HIF1α genes in the combination group compared to the monotherapy groups (P < 0.001). ConclusionConsidering that resveratrol can increase the apoptosis of cancer cells alone and in combination with tivozanib and prevent the proliferation of cancer cells and also reduce the side effects of tivozanib, we suggest that resveratrol as a potential bioactive molecule can be used in treatment of kidney cancer should be used in combination with tivozanib.

Unveiling the apoptotic potential of antioxidant-rich Bangladeshi medicinal plant extractives and computational modeling to identify antitumor compounds

Nowadays, there has been a significant surge in the exploration of anticancer compounds derived from medicinal plants due to their perceived safety and efficacy. Therefore, our objective was to investigate the antioxidant and antiproliferative properties, along with the phytoconstituents, of methanol extracts from various parts of 15 selected Bangladeshi medicinal plants. Standard spectrophotometric methods and confocal microscopy were utilized to assess the antioxidant and antiproliferative potential of these extracts. Additionally, phytochemical profiling was executed through gas chromatography-mass spectrometry (GC-MS) analysis. Among the extractives, Bombax ceiba bark exhibited the highest scavenging capacity against DPPH (IC50: 10.3 ± 0.7 μg/mL) and hydroxyl (IC50: 3.9 ± 0.1 μg/mL) free radicals. Furthermore, the total antioxidants, reducing power, and polyphenols of B. ceiba bark were higher than those of other extracts. B. ceiba bark also showed significant antiproliferative capacity against MCF-7 cells (86.67 %) in the MTT assay, followed by Cocos nucifera roots (83.92 %), Bixa orellana leaves (44.09 %), and Leea macrophylla roots (25 %). Moreover, B. ceiba bark, L. macrophylla roots, C. nucifera roots, and B. orellana leaves-treated Ehrlich ascites carcinoma (EAC) cells demonstrated growth inhibition rates of 87.27 %, 80.45 %, 42.9 %, and 37.27 %, respectively. Fluorescence microscopic analysis of EAC cells treated with these extracts revealed apoptotic features such as condensed chromatin, cell shrinkage, nucleus fragmentation, and membrane blebbing compared to untreated EAC cells. The GC-MS analysis of B. ceiba bark identified 18 compounds, including various alcohols, alkenes, and esters. Additionally, a molecular docking study revealed oxalic acid, cyclohexyl dodecyl ester as the most potent compound (−6.5) active against breast cancer. In summary, our results demonstrate that B. ceiba bark possesses robust antioxidant and antiproliferative properties, along with potent antitumor compounds, which could be utilized in the treatment of carcinoma.

The AMS-02 Cosmic-Ray Deuteron Flux is Consistent with a Secondary Origin

The recent measurements of cosmic-ray (CR) deuteron fluxes by AMS-02 show that the rigidity dependence of deuterons is similar with that of protons but flatter than 3He, which has been attributed to the existence of primary deuterons with abundance much higher than that from the Big Bang nucleosynthesis. The requirement of highly deuteron-abundant sources imposes a serious challenge to modern astrophysics since there is no known process to produce a large amount of deuterons without violating other constraints. In this work we demonstrate that the fragmentation of heavy nuclei up to nickel plays a crucial role in shaping/enhancing the spectrum/flux of the CR deuterons. Based on the latest CR data, the predicted secondary fluxes of deuterons and 3He are found to be reasonably consistent with the AMS-02 measurements, and a primary deuteron component is not needed. The observed differences between the spectra of D and 3He, as well as those between the D/4He (D/p) and 3He/4He (3He/p) flux ratios, measured in the rigidity space, is probably due to the kinetic-energy-to-rigidity conversion and the solar modulation, given different charge-to-mass ratios of D and 3He. More precise measurements of the fragmentation cross sections of various nuclei to produce deuterons, tritons, and 3He in a wide energy range will be very helpful in further testing the secondary origin of cosmic-ray deuterons.

Intratympanic injection of MSC-derived small extracellular vesicles protects spiral ganglion neurons from degeneration

Sensorineural hearing loss is one of the most prevalent sensory deficits. Spiral ganglion neurons (SGNs) exhibit very limited regeneration capacity and their degeneration leads to profound hearing loss. Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEV) have been demonstrated to repair tissue damage in various degenerative diseases. However, the effects of MSC-sEV on SGN degeneration remain unclear. In this study, we investigated the efficacy of MSC-sEV for protection against ouabain-induced SGN degeneration. MSC-sEV were derived from rat bone marrow and their components related to neuron growth were determined by proteomic analysis. In primary culture SGNs, MSC-sEV significantly promoted neurite growth and growth cone development. The RNA-Seq analysis of SGNs showed that enriched pathways include neuron development and axon regeneration, consistent with proteomics. In ouabain induced SGN degeneration rat model, MSC-sEV administration via intratympanic injection significantly enhanced SGN survival and mitigated hearing loss. Furthermore, after ouabain treatment, SGNs displayed evident signs of apoptosis, including nuclei condensation and fragmentation, with numerous cells exhibiting TUNEL-positive. However, administration of MSC-sEV effectively decreased the number of TUNEL-positive cells and reduced caspase-3 activation. In conclusion, our findings demonstrate the potential of MSC-sEV in preventing SGN degeneration and promoting neural growth, suggesting intratympanic injection of MSC-sEV is a specific and efficient strategy for neural hearing loss.

Four-port bimanual phaco-chop fragmentation for dropped nucleus using standard phaco chopper and assistant handheld 23G endoilluminator

Abstract: PURPOSE: To describe a bimanual method for management of posteriorly dislocated large nucleus fragment using standard chopper. METHODS: A 23G assistant handheld endoilluminator was used as light source through inferonasal self-sealing port, while the large nuclear fragment was broken into smaller fragments using phacofragmatome and standard phaco chopper. RESULTS: A case of posteriorly dislocated large nuclear fragment was operated using this technique. The time taken for phacofragmentation was significantly reduced, as well as the ultrasound energy required for the same. There was no port site complication. CONCLUSION: This technique allows greater maneuverability and reduces amount of ultrasound energy used by dividing nucleus into small fragments in vitreous cavity.

Post-mortem Interval estimate based on dental pulp: A histomorphology approach.

Estimating the post-mortem interval (PMI) of human remains based on the histomorphology of dental pulp parameters is promising, but available evidence is scarce and sometimes contradictory without a scientific model. The aim of the study is to characterise the histomorphological changes of dental pulp associated with the decomposition of human remains by a qualitative and quantitative approach. The main aim is to establish a correlation based on post-mortem (PM) dental pulp histomorphology and the PMI, and whether pulp degradation could be an available medico-legal tool for PMI estimation beyond the first week after death (late PMI). The eligible sample consisted of 27 sound teeth from 16 healthy patients aged 16 to 72 years due to orthodontic or oral surgery treatment, to create PMI's simulating the death of the subject as the time elapsed from tooth avulsion. Data collected from patients (sex, date of birth, tooth position, date and hour of the avulsion, date and hour of pulp extraction) were anonymised in accordance with the requirements of Faculty of Dental Medicine of the University of Lisbon. The sample was divided into 9 groups of 3 teeth according to different PMI sets from T0 (baseline) up to 2 weeks (T0, 7, 12, 24, 36, 48, and 72 hours, 1 and 2 weeks). All the dental samples were stored at room temperature up to the time of pulp extraction and then prepared with haematoxylin and eosin stain. High-resolution microscopy was performed to obtain histological images. An operator performed the qualitative evaluation of blood vessels, collagen fibres, and the extra-cellular matrix (ECM) in PM pulps and measured the variation in cells/nuclei density by counting 6 different ROIs (Regions of Interest) for each pulp manually and automatically (quantitative analysis). Qualitative results showed that the degeneration of dental pulp appears 7 hours after death but histological changes in vessels, fibres, and ECM in PM dental pulp are characterised by high variability, consequently it is not possible to generalise the results for early PMIs. Quantitative measurements proved that cell count cannot be standardised due to the presence of superimposed layers of cells and nuclei fragmentation. Odontoblasts did not demonstrate evidence of cellular or nuclear lysis up to 14 PM suggesting their applicability in late PMIs. Future research will focus on late PMIs and different techniques of tooth preparation.

Recombinant Methioninase Is Selectively Synergistic With Doxorubicin Against Wild-type Fibrosarcoma Cells Compared to Normal Cells and Overcomes Highly-Doxorubicin-resistant Fibrosarcoma.

Doxorubicin is first-line therapy for soft-tissue sarcoma, but patients can develop resistance which is usually fatal. As a novel therapeutic strategy, the present study aimed to determine the synergy of recombinant methioninase (rMETase) and doxorubicin against HT1080 fibrosarcoma cells compared to Hs27 normal fibroblasts, and rMETase efficacy against doxorubicin-resistant HT1080 cells in vitro. The 50% inhibitory concentrations (IC50) of doxorubicin and rMETase, as well as their combination efficacy, against HT1080 human fibrosarcoma cells, Hs27 normal human fibroblasts and doxorubicin-resistant HT1080 (DR-HT1080) cells were determined. Dual-color HT1080 cells which expressed red fluorescent protein (RFP) in the cytoplasm and green fluorescent protein (GFP) in the nuclei were used to visualize nuclear fragmentation during treatment. Nuclear fragmentation was observed with an IX71 fluorescence microscope. The IC50 for doxorubicin was 3.3 μM for HT1080 cells, 12.4 μM for DR-HT1080 cells, and 7.25 μM for Hs27 cells. The IC50 for rMETase was 0.75 U/ml for HT1080 cells, 0.42 U/ml for DR-HT1080 cells, and 0.93 U/ml for Hs27 cells. The combination of rMETase and doxorubicin was synergistic against fibrosarcoma cells but not against normal fibroblasts. The combination of doxorubicin plus rMETase also caused more fragmented nuclei than either treatment alone in HT1080 cells. rMETase alone was highly effective against the DR-HT1080 cells as well as the parental HT1080 cells. The present results indicate the future clinical potential of rMETase in combination with doxorubicin for fibrosarcoma, including doxorubicin-resistant fibrosarcoma.

Organization of the Nuclei in the Tegument of Some Palaeacanthocephala and Archiacanthocephala.

The giant tegument nuclei of the acanthocephalans of the classes Archiacanthocephala and Palaeacanthocephala are fragmented at the final stage of cystacanthus formation in the intermediate host, but remain connected with each other during later life. It can be assumed that the fragments of each giant tegument nucleus are united with each other to form an independent network that ensures the vital activity of the tegument, the volume of which increases many times during the period of intensive growth of the parasite in the definitive host.

Abstract PR001: KIF18A inhibition, via ATX020, leads to mitotic arrest and robust anti-tumor activity through a synthetic lethal interaction with chromosome instability

Abstract KIF18A is a plus-end directed kinesin known to play a role in mitosis by facilitating chromosome alignment and spindle microtubule dynamics. Knockdown or knockout of KIF18A has been shown to inhibit proliferation in cells with whole genome doubling or aneuploidy, cellular states characterized by chromosomal rearrangements. These alterations render cells particularly vulnerable to disrupted mitosis upon KIF18A loss. As such, KIF18A is a compelling synthetic lethality target in a subset of tumors with chromosomal instability (CIN), which have ongoing chromosomal segregation defects. We have identified potent and selective small molecule inhibitors of KIF18A. A proprietary tool compound, ATX020, inhibits KIF18A ATPase activity with an IC50 of 0.014 µM; KIF18A is selectively inhibited over other kinesins including CENPE (IC50 &amp;gt; 10 µM) and EG5 (IC50 5.87 µM). ATX020 exhibits robust cellular activity, with anti-proliferative activity observed in chromosomally instable ovarian cancer cell lines such as OVCAR-3 (IC50 0.053 µM) and OVCAR-8 (IC50 0.54 µM). Upon treatment with ATX020, Annexin V is robustly induced in sensitive cell lines, demonstrating that KIF18A-dependent cell lines undergo apoptosis upon KIF18A inhibition. In KIF18Ai sensitive cells, a dose-dependent upregulation of phospho-Histone H3 and gamma-H2AX is observed upon ATX020 treatment in OVCAR-3 and OVCAR-8 cells, consistent with the induction of mitotic arrest and DNA damage. In these sensitive cell lines, ATX020 induces a dose-dependent cell cycle arrest in G2/M, consistent with the role of KIF18A in facilitating mitosis. OVCAR-3 cells treated with ATX020 exhibit fragmented nuclei and malformed mitotic spindles. In contrast, CIN negative Ovarian cancer cells that are insensitive to KIF18A loss, such as A2780 and OVK18, proliferate normally upon ATX020 treatment, cell division is unaffected, and no induction of Annexin V, phospho-Histone H3, and gamma-H2AX is observed. This selective dependency is also observed in vivo, where administration of ATX020 leads to dose-dependent tumor growth inhibition in an OVCAR-3 cancer cell line-derived xenograft model, with significant tumor regression observed at 100 mpk/day. In contrast, OVK18 tumors are unaffected by ATX020 administration, as expected based on the lack of cell cycle and proliferation effects in that cell line. Together, these data demonstrate a critical role for KIF18A in facilitating mitosis in a subset of chromosomally instable cells. These effects are selective, with KIF18A-independent cell lines proceeding through the cell cycle normally in the presence of inhibitors. Small molecule inhibition of KIF18A is therefore expected to have robust efficacy in solid tumors with high levels of chromosomal instability such as Ovarian cancer. Citation Format: Maureen S. Lynes, Laura Ghisolfi, Sanjoy Khan, Taylor Hotz, Brian A. Sparling, Mary-Margaret Zablocki, Deepali Gotur, P. Ann Boriack-Sjodin, Kenneth W. Duncan, Stephen J. Blakemore, Serena J. Silver, Robert A. Copeland. KIF18A inhibition, via ATX020, leads to mitotic arrest and robust anti-tumor activity through a synthetic lethal interaction with chromosome instability [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 PR001.

Cordyceps militaris: A Comprehensive Study on Laboratory Cultivation and Anticancer Potential in Dalton's Ascites Lymphoma Tumor Model.

Cancer, a predominant cause of mortality, poses a formidable challenge in our pursuit of elevating life expectancy. Throughout history, individuals have sought natural remedies with minimal side effects as an appealing substitute for chemotherapeutic drugs. One such remedy is Cordyceps militaris, a renowned medicinal mushroom deeply entrenched in Asian ethnomedicine. Revered for its rejuvenating and curative attributes, it relied upon for ages. The mushroom's soaring demand outpaced natural availability, necessitating controlled laboratory cultivation as the core focus and exploring the potential of methanolic extracts from harvested Cordyceps militaris fruiting bodies against Dalton's Lymphoma Ascites (DLA) cells in vitro, with a specific emphasis on its anticancer traits. For cultivation, we employed a diverse range of rice substrates, among which bora rice showed promising growth of C. militaris fruiting bodies. To assess DLA cell cytotoxicity, several assays, including trypan blue exclusion assay, MTT assay, and LDH assay, were employed at different time points (24-96 h), which provided valuable insights on DLA cell viability and proliferation, shedding light on its therapeutic potential against cancer. Our studies unveiled that methanolic extract prompts apoptosis in DLA cells via AO/EB dual staining, manifesting consistent apoptosis indicators such as membrane blebbing, chromatin condensation, nuclei fragmentation, and cellular shrinkage at 48-96 h of treatment. Furthermore, these striking repercussions of apoptosis were comprehended by an in silico approach having molecular docking simulation against antiapoptotic proteins like BCL-2, BCL-XL, MCL-1, BFL-1 & HSP100. Methanolic C. militaris extracts exhibited cytotoxicity and apoptotic alterations in DLA cells.

Клинический случай идиопатической формы синдрома Свита

Background. Sweet’s syndrome (acute febrile neutrophilic dermatosis) is an extremely rare disease of the group of neutrophilic dermatoses with undulating courses of illness, which is an inflammatory non-infectious skin reaction characterized histopathologically by the presence of dense diffuse neutrophil infiltrate in the dermis without signs of leukocytoclastic vasculitis, edema and fragmentation of neutrophil nuclei. The mechanism of development of this disease is presumably associated with a cytokine-mediated hypersensitivity reaction followed by neutrophil infiltration of the dermis, however, the etiology of the development of this pathogenesis is not known. Sweet syndrome is a current problem, since complications can occur in the form of damage to the organs of the central nervous system, eyes, lungs, skin breakdown, as well as changes in the immune system in the form of immunodeficiency. Aim. To evaluate, describe, study the courses and complications of the idiopathic form of Sweet’s syndrome. Materials and methods. Study of examination data of a (3-year-old girld) who was being treated at the department of pulmonology of Kursk Regional Children's Clinical Hospital. Study and analysis of scientific literature on the problem of Sweet's syndrome. Conclusion. As a result of studying this Clinical case, we came to the conclusion that despite the fact that Sweet’s syndrome is an extremely rare disease and more often debuts at the age of 60, it can also be observed in children, which must be taken into account in the presence of a skin rash without a known etiology and pathogenesis. Since complications may occur, it is necessary to identify and treat exacerbations of this disease in a timely manner. The prognosis of the disease is relatively favorable, since complications of Sweet’s syndrome can lead to a decrease in the quality of life of patients.

Copper(I) complexes of acylthiourea ligands: structural insights and cytotoxic potential

The reaction of substituted acylthiourea derivatives (L1–L4) with [(PPh3)2Cu(μ‐Cl)2Cu(PPh3)] in a proper stoichiometric proportion gave the complexes (1–4) in good yields. The structures of the compounds (ligands and complexes) were advocated through spectroscopic analyses and x‐ray diffraction (XRD) studies; the latter confirmed their molecular structures. The complexes (1–4) were assessed for their cytotoxic potential through MTT assay against A549, T24, and HepG2 cancer cells, and their toxicity was evaluated using Vero and MCF‐10a normal cells. The complexes (1–4) displayed better cytotoxic action toward HepG2 cancer cells than cisplatin. Complexes 3 and 4 significantly destroyed A549 cancer cells with the IC50 values of 16.25 and 4.90 μM, respectively, which were lower than that of cisplatin (IC50 = 17.73 μM). Furthermore, the higher IC50 values in normal cells showed that the complexes were less hazardous to the normal cells except complex 3. The biocompatibility study showed that the complexes had minimal impact on normal human dermal fibroblast (NHDF) cells. The mode of cell death of complexes 3 and 4 against cancer cells was evaluated using staining assays. Both compounds demonstrated a significant reduction in live cells, an increase in early apoptotic cells, and pronounced proapoptotic effects, as evidenced by fragmented nuclei. Flow cytometry revealed a distinctive subpopulation in the subG0 phase, highlighting the compounds' ability to induce apoptosis and inhibit cell cycle progression.

The role of nuclear fragmentations in high energy transfers to a micro-object exposed to primary space radiation.

This paper describes events of anomalously high energy transfer to a micro-object by fragments of nuclei generated in nuclear interactions in the environment on board a spacecraft in flight in low-Earth orbit. An algorithm has been developed that allows for the calculation of the absorbed energy from one or more fragments - products of nuclear interaction. With this algorithm the energy distributions for a spherical micro-volume in an aqueous medium were calculated. And the resulting absorbed energy spectra from nuclear fragments and from primary cosmic rays were compared. The role of nuclear interactions in events of large energy transfers in micro-objects in the field of primary cosmic radiation has been evaluated. The calculations performed in this study showed that the energy in a micro-volume from nuclear events can be several times higher compared to the energy imparted by primary space radiation.

Abstract 3095: A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase

Abstract Werner helicase (WRN) is a RecQ DNA helicase involved in genome maintenance and DNA damage repair. It has recently been shown to be essential to cancer cells with high microsatellite instability (MSI-H). In MSI-H cancer cells, WRN depletion was shown to induce DNA damage and disrupt mitoses, resulting in a distinct phenotype of enlarged and fragmented nuclei. Here, we present a high-throughput phenotypic screen to identify compounds that selectively induce enlarged nuclei in MSI-H cancer cells. In HCT116, an MSI-H colorectal cancer cell line, approximately 40% of cells exhibited enlarged nuclei when WRN was depleted using siRNA. In contrast, fewer than 10% of control cells displayed this phenotype. In HT29, a microsatellite stable (MSS) cancer cell line, no such difference in nuclear morphology was observed, suggesting that the phenotype is specific to MSI-H cells. We used high content imaging to screen our in-house diversity library of approximately 175,000 compounds in 384-well format. 4,260 compounds induced enlarged nuclei in HCT116 cells, a 2.4% hit rate. After re-screening hits in HCT116 along with two additional MSI-H cancer cell lines, SW48 and SNU-407, and counter-screening in HT29 cells, 144 hits were confirmed to specifically enlarge nuclei in MSI-H but not MSS cells. Using the ADP-Glo Kinase Assay, two of these compounds were confirmed to inhibit WRN ATPase activity, suggesting WRN inhibition as a potential mechanism for their specific effects in MSI-H cells. This screen will also identify compounds which selectively kill MSI-H cells through mechanisms beyond direct inhibition of WRN, including interaction with WRN complex members or other members of DNA damage repair pathways. Validation studies including the assessment of cell viability and DNA damage in a panel of MSI-H and MSS cell lines will be performed. Our study proposes a phenotypic screening strategy for identifying small molecules with the potential to target WRN and uncover additional novel mechanisms for treating MSI-H cancers. Citation Format: Christine A. Moomau, Yipin Lu, Xiaobin Zhang, Xiang Zhai, Lina Gu, Qing Sheng, Fang Li, Yaoyu Chen. A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3095.

Abstract 3337: Inhibition of KIF18A leads to mitotic arrest and robust anti-tumor activity in chromosomally instable tumors

Abstract KIF18A is a plus-end directed kinesin known to play a role in mitosis by facilitating chromosome alignment and spindle microtubule dynamics. Knockdown or knockout of KIF18A has been shown to inhibit proliferation in cells with whole genome doubling or aneuploidy, cellular states characterized by chromosomal rearrangements. These alterations render cells particularly vulnerable to disrupted mitosis upon KIF18A loss. As such, KIF18A is a compelling target in a subset of tumors with chromosomal instability (CIN), which have ongoing chromosomal segregation defects. We have identified potent and selective small molecule inhibitors of KIF18A. A proprietary tool compound, ATX-21020, inhibits KIF18A ATPase activity with an IC50 of 14.5 nM; KIF18A is selectively inhibited over other kinesins including CENPE (IC50 &amp;gt; 10 µM) and EG5 (IC50 5.87 µM). ATX-21020 exhibits robust cellular activity, with anti-proliferative activity observed in chromosomally instable ovarian cancer cell lines such as OVCAR-3 (IC50 53.3 nM) and OVCAR-8 (IC50 0.54 µM). Upon treatment with ATX-21020, Annexin V is robustly induced in sensitive cell lines, demonstrating that KIF18A-dependent cell lines undergo apoptosis upon KIF18A inhibition. In KIF18Ai sensitive cells, a dose-dependent upregulation of phospho-Histone H3 and gamma-H2AX is observed upon ATX-21020 treatment in OVCAR-3 and OVCAR-8 cells, consistent with the induction of mitotic arrest and DNA damage. In contrast, CIN negative Ovarian cancer cells that are insensitive to KIF18A loss, such as A2780 and OVK18, proliferate normally upon ATX-21020 treatment, and Annexin V, phospho-Histone H3, and gamma-H2AX are not induced. In sensitive cell lines, ATX-21020 induces a dose-dependent cell cycle arrest in G2/M, consistent with the role of KIF18A in facilitating mitosis. OVCAR-3 cells treated with ATX-21020 exhibit fragmented nuclei and malformed mitotic spindles, in contrast to A2780 cells where cell division is unaffected, suggesting that KIF18A is dispensable in CIN negative cells. This selective dependency is also observed in vivo, where administration of ATX-21020 leads to dose-dependent tumor growth inhibition in an OVCAR-3 cancer cell line-derived xenograft model, with significant tumor regression observed at 100 mpk/day. In contrast, OVK18 tumors are unaffected by ATX-21020 administration, as expected based on the lack of cell cycle and proliferation effects in that cell line. Together, these data demonstrate a critical role for KIF18A in facilitating mitosis in a subset of chromosomally instable cells. These effects are selective, with KIF18A-independent cell lines proceeding through the cell cycle normally in the presence of inhibitors. Small molecule inhibition of KIF18A is therefore expected to have robust efficacy in solid tumors with high levels of chromosomal instability such as Ovarian cancer. Citation Format: Maureen S. Lynes, Sanjoy Khan, Taylor Hotz, Brian A. Sparling, Mary-Margaret Zablocki, Deepali Gotur, P Ann Boriack-Sjodin, Kenneth W. Duncan, Stephen J. Blakemore, Serena J. Silver, Robert A. Copeland. Inhibition of KIF18A leads to mitotic arrest and robust anti-tumor activity in chromosomally instable tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3337.

First in-human clinical performance of a new non-cavitating handheld lensectomy system in 665 consecutive cataract surgeries.

To investigate the intraoperative performance and lens fragmentation efficacy of a non-cavitating handheld lensectomy system in mild, moderate, and severe cataract. Ambulatory surgical centers. Retrospective consecutive case series. 665 consecutive eyes underwent cataract surgery by 12 surgeons using a new handheld non-cavitating lensectomy system for nuclear fragmentations and extraction. Intraoperative measurements included surgical time, miLOOP pretreatment, and irrigation fluid use. Of the 665 eyes, 38 (6%), 468 (70%), 126 (19%), and 33 (5%) were of grade 1, 2, 3, and 4 nuclear densities, respectively, as graded by the surgeon intraoperatively. Successful nuclear fragmentation, lens extraction, and cortical removal were achieved in all eyes. Total nucleus fragmentation and extraction times were 70.1 seconds, 100.3 seconds, 132.6 seconds, and 287.9 seconds for grades 1, 2, 3, and 4, respectively ( P < .001). In addition, irrigation and aspiration cortical removal times were 64.1 seconds, 51.1 seconds, 48.5 seconds, and 59.0 seconds, respectively ( P = .14). There was a low rate of capsular tear (3 cases in 665 surgeries, 0.45%) and no other emergent adverse events. The miCOR handheld non-cavitating lensectomy system demonstrated nuclear fragmentation and extraction in the absence of intraocular cavitation across all grades of nuclear densities.