Contributions of Chinese hamster ovary cell derived extracellular vesicles and other cellular materials to hollow fiber filter fouling during perfusion manufacturing of monoclonal antibodies

Hollow fiber filter fouling is a common issue plaguing perfusion production process for biologics therapeutics, but the nature of filter foulant has been elusive. Here we studied cell culture materials especially Chinese hamster ovary (CHO) cell-derived extracellular vesicles in perfusion process to determine their role in filter fouling. We found that the decrease of CHO-derived small extracellular vesicles (sEVs) with 50-200 nm in diameter in perfusion permeates always preceded the increase in transmembrane pressure (TMP) and subsequent decrease in product sieving, suggesting that sEVs might have been retained inside filters and contributed to filter fouling. Using scanning electron microscopy and helium ion microscopy, we found sEV-like structures in pores and on foulant patches of hollow fiber tangential flow filtration filter (HF-TFF) membranes. We also observed that the Day 28 TMP of perfusion culture correlated positively with the percentage of foulant patch areas. In addition, energy dispersive X-ray spectroscopy-based elemental mapping microscopy and spectroscopy analysis suggests that foulant patches had enriched cellular materials but not antifoam. Fluorescent staining results further indicate that these cellular materials could be DNA, proteins, and even adherent CHO cells. Lastly, in a small-scale HF-TFF model, addition of CHO-specific sEVs in CHO culture simulated filter fouling behaviors in a concentration-dependent manner. Based on these results, we proposed a mechanism of HF-TFF fouling, in which filter pore constriction by CHO sEVs is followed by cake formation of cellular materials on filter membrane.

Role of Hydroperoxyl Radicals in Heterogeneous Oxidation of Oxygenated Organic Aerosols

Heterogeneous oxidative aging of organic aerosols (OA) occurs ubiquitously in the atmosphere, initiated by oxidants, such as the hydroxyl radicals (•OH). Hydroperoxyl radicals (HO2•) are also an important oxidant in the troposphere, and its gas-phase chemistry has been well studied. However, the role of HO2• in heterogeneous OA oxidation remains elusive. Here, we carry out •OH-initiated heterogeneous oxidation of several OA model systems under different HO2• conditions in a flow tube reactor and characterize the molecular oxidation products using a suite of mass spectrometry instrumentation. By using hydrogen-deuterium exchange (HDX) with thermal desorption iodide-adduct chemical ionization mass spectrometry, we provide direct observation of organic hydroperoxide (ROOH) formation from heterogeneous HO2• and peroxy radicals (RO2•) reactions for the first time. The ROOH may contribute substantially to the oxidation products, varied with the parent OA chemical structure. Furthermore, by regulating RO2• reaction pathways, HO2• also greatly influence the overall composition of the oxidized OA. Last, we suggest that the RO2• + HO2• reactions readily occur at the OA particle interface rather than in the particle bulk. These findings provide new mechanistic insights into the heterogeneous OA oxidation chemistry and help fill the critical knowledge gap in understanding atmospheric OA oxidative aging.

Subtle microstructural alterations in white matter tracts involved in socio-emotional processing after very preterm birth

Children born very preterm (VPT, < 32 weeks of gestation) have an increased risk of developing socio-emotional difficulties. Possible neural substrates for these socio-emotional difficulties are alterations in the structural connectivity of the social brain due to premature birth. The objective of the current study was to study microstructural white matter integrity in VPT versus full-term (FT) born school-aged children along twelve white matter tracts involved in socio-emotional processing. Diffusion MRI scans were obtained from a sample of 35 VPT and 38 FT 8-to-12-year-old children. Tractography was performed using TractSeg, a state-of-the-art neural network-based approach, which offers investigation of detailed tract profiles of fractional anisotropy (FA). Group differences in FA along the tracts were investigated using both a traditional and complementary functional data analysis approach. Exploratory correlations were performed between the Social Responsiveness Scale (SRS-2), a parent-report questionnaire assessing difficulties in social functioning, and FA along the tract. Both analyses showed significant reductions in FA for the VPT group along the middle portion of the right SLF I and an anterior portion of the left SLF II. These group differences possibly indicate altered white matter maturation due to premature birth and may contribute to altered functional connectivity in the Theory of Mind network which has been documented in earlier work with VPT samples. Apart from reduced social motivation in the VPT group, there were no significant group differences in reported social functioning, as assessed by SRS-2. We found that in the VPT group higher FA values in segments of the left SLF I and right SLF II were associated with better social functioning. Surprisingly, the opposite was found for segments in the right IFO, where higher FA values were associated with worse reported social functioning. Since no significant correlations were found for the FT group, this relationship may be specific for VPT children. The current study overcomes methodological limitations of previous studies by more accurately segmenting white matter tracts using constrained spherical deconvolution based tractography, by applying complementary tractometry analysis approaches to estimate changes in FA more accurately, and by investigating the FA profile along the three components of the SLF.

A Mechanistic Understanding of the Modes of Ca2+ Ion Binding to the SARS-CoV-1 Fusion Peptide and Their Role in the Dynamics of Host Membrane Penetration

The SARS-CoV-1 spike glycoprotein contains a fusion peptide (FP) segment that mediates the fusion of the viral and host cell membranes. Calcium ions are thought to position the FP optimally for membrane insertion by interacting with negatively charged residues in this segment (E801, D802, D812, E821, D825, and D830); however, which residues bind to calcium and in what combinations supportive of membrane insertion are unknown. Using biological assays and molecular dynamics studies, we have determined the functional configurations of FP-Ca2+ binding that likely promote membrane insertion. We first individually mutated the negatively charged residues in the SARS CoV-1 FP to assay their roles in cell entry and syncytia formation, finding that charge loss in the D802A or D830A mutants greatly reduced syncytia formation and pseudoparticle transduction of VeroE6 cells. Interestingly, one mutation (D812A) led to a modest increase in cell transduction, further indicating that FP function likely depends on calcium binding at specific residues and in specific combinations. To interpret these results mechanistically and identify specific modes of FP-Ca2+ binding that modulate membrane insertion, we performed molecular dynamics simulations of the SARS-CoV-1 FP and Ca2+ions. The preferred residue pairs for Ca2+ binding we identified (E801/D802, E801/D830, and D812/E821) include the two residues found to be essential for S function in our biological studies (D802 and D830). The three preferred Ca2+ binding pairs were also predicted to promote FP membrane insertion. We also identified a Ca2+ binding pair (E821/D825) predicted to inhibit FP membrane insertion. We then carried out simulations in the presence of membranes and found that binding of Ca2+ to SARS-CoV-1 FP residue pairs E801/D802 and D812/E821 facilitates membrane insertion by enabling the peptide to adopt conformations that shield the negative charges of the FP to reduce repulsion by the membrane phospholipid headgroups. This calcium binding mode also optimally positions the hydrophobic LLF region of the FP for membrane penetration. Conversely, Ca2+ binding to the FP E801/D802 and D821/D825 pairs eliminates the negative charge screening and instead creates a repulsive negative charge that hinders membrane penetration of the LLF motif. These computational results, taken together with our biological studies, provide an improved and nuanced mechanistic understanding of the dymanics of SARS-CoV-1 calcium binding and their potential effects on host cell entry.

Chronic oxytocin administration stimulates the oxytocinergic system in children with autism

Clinical efficacy of intranasal administration of oxytocin is increasingly explored in autism spectrum disorder, but to date, the biological effects of chronic administration regimes on endogenous oxytocinergic function are largely unknown. Here exploratory biological assessments from a completed randomized, placebo-controlled trial showed that children with autism (n = 79, 16 females) receiving intranasal oxytocin for four weeks (12 IU, twice daily) displayed significantly higher salivary oxytocin levels 24 hours after the last oxytocin nasal spray administration, but no longer at a four-week follow up session. Regarding salivary oxytocin receptor gene (OXTR) epigenetics (DNA-methylation), oxytocin-induced reductions in OXTR DNA-methylation were observed, suggesting a facilitation of oxytocin receptor expression in the oxytocin compared to the placebo group. Notably, heightened oxytocin levels post-treatment were significantly associated with reduced OXTR DNA-methylation and improved feelings of secure attachment. These findings indicate that four weeks of chronic oxytocin administration stimulated the endogenous oxytocinergic system in children with autism.

Oxidation of Per- and Polyfluoroalkyl Ether Acids and Other Per- and Polyfluoroalkyl Substances by Sulfate and Hydroxyl Radicals: Kinetic Insights from Experiments and Models

Per- and polyfluoroalkyl substances (PFAS) are widely used anthropogenic chemicals. Because of the strength of the carbon-fluorine bond, PFAS are not destroyed in typical water treatment processes. Sulfate (SO4•-) and hydroxyl (•OH) radicals can oxidize some PFAS, but the behavior of per- and polyfluoroalkyl ether acids (PFEAs) in processes involving SO4•- and •OH is poorly understood. In this study, we determined second-order rate constants (k) describing the oxidation of 18 PFAS, including 15 novel PFEAs, by SO4•- and •OH. Among the studied PFAS, 6:2 fluorotelomer sulfonate reacted most readily with •OH [k•OH = (1.1-1.2) × 107 M-1 s-1], while polyfluoroalkyl ether acids containing an -O-CFH- moiety reacted more slowly [k•OH = (0.5-1.0) × 106 M-1 s-1]. In the presence of SO4•-, polyfluoroalkyl ether acids with an -O-CFH- moiety reacted more rapidly [kSO4•- = (0.89-4.6) × 106 M-1 s-1] than perfluoroalkyl ether carboxylic acids (PFECAs) and a chloro-perfluoro-polyether carboxylic acid (ClPFPECA) [kSO4•- = (0.85-9.5) × 104 M-1 s-1]. For homologous series of perfluoroalkyl carboxylic acids, linear and branched monoether PFECAs, and multiether PFECAs, PFAS chain length had little impact on second-order rate constants. SO4•- reacted with the carboxylic acid headgroup of perfluoroalkyl carboxylic acids and PFECAs. In contrast, for polyfluoroalkyl ether carboxylic and sulfonic acids with an -O-CFH- moiety, the site of SO4•- attack was the -O-CFH- moiety. Perfluoroalkyl ether sulfonic acids were not oxidized by SO4•- and •OH under the conditions evaluated in this study.

Can repeated intranasal oxytocin administration affect reduced neural sensitivity towards expressive faces in autism? A randomized controlled trial

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties in social communication and interaction. Crucial for efficient social interaction is the ability to quickly and accurately extract information from a person's face. Frequency-tagging electroencephalography (EEG) is a novel tool to quantify face-processing sensitivity in a robust and implicit manner. In terms of intervention approaches, intranasal administration of oxytocin (OT) is increasingly considered as a potential pharmacological approach for improving socio-communicative difficulties in ASD, through enhancing social salience and/or reducing (social) stress and anxiety.

METHODS

In this randomized, double-blind, placebo-controlled, mechanistic pharmaco-neuroimaging clinical trial, we implemented frequency-tagging EEG to conduct an exploratory investigation into the impact of repeated OT administration (4 weeks, 12 IU, twice daily) on neural sensitivity towards happy and fearful facial expressions in children with ASD (8-12 years old; OT: n = 29; placebo: n = 32). Neural effects were assessed at baseline, post-nasal spray (24 hr after the last nasal spray) and at a follow-up session, 4 weeks after the OT administration period. At baseline, neural assessments of children with ASD were compared with those of an age- and gender-matched cohort of neurotypical (NT) children (n = 39).

RESULTS

Children with ASD demonstrated reduced neural sensitivity towards expressive faces, as compared to NT children. Upon nasal spray administration, children with ASD displayed a significant increase in neural sensitivity at the post- and follow-up sessions, but only in the placebo group, likely reflecting an implicit learning effect. Strikingly, in the OT group, neural sensitivity remained unaffected from the baseline to the post-session, likely reflecting a dampening of an otherwise typically occurring implicit learning effect.

CONCLUSIONS

First, we validated the robustness of the frequency-tagging EEG approach to assess reduced neural sensitivity towards expressive faces in children with ASD. Furthermore, in contrast to social salience effects observed after single-dose administrations, repeated OT administration dampened typically occurring learning effects in neural sensitivity. In line with OT's social anxiolytic account, these observations possibly reflect a predominant (social) stress regulatory effect towards emotionally evocative faces after repeated OT administration.

Clinical features and prognostic outcomes of angioimmunoblastic T cell lymphoma in an Asian multicenter study

In our Asian multicenter retrospective study, we investigated the clinical prognostic factors affecting the outcomes of AITL patients and identified a novel prognostic index relevant in the Asian context. In our 174-patient cohort, the median PFS and OS was 1.8 years and 5.6 years respectively. Age > 60, bone marrow involvement, total white cell count >12 × 109/L and raised serum lactate dehydrogenase were associated with poorer PFS and OS in multivariate analyses. This allowed for a prognostic index (AITL-PI) differentiating patients into low (0-1 factors, n = 64), moderate (2 factors, n = 59) and high-risk (3-4 factors, n = 49) subgroups with 5-year OS of 84.0%, 44.0% and 28.0% respectively (p < 0.0001). POD24 proved to be strongly prognostic (5-year OS 24% vs 89%, p < 0.0001). Exploratory gene expression studies were performed and disparate immune cell profiles and cell signaling signatures were seen in the low risk group as compared to the intermediate and high risk groups.

At the Head and Heart of Oxytocin's Stress-Regulatory Neural and Cardiac Effects: A Chronic Administration RCT in Children with Autism

INTRODUCTION

Intranasal administration of oxytocin presents a promising new approach to reduce disability associated with an autism spectrum disorder diagnosis. Previous investigations have emphasized the amygdala as the neural foundation for oxytocin's acute effects. However, to fully understand oxytocin's therapeutic potential, it is crucial to gain insight into the neuroplastic changes in amygdala circuitry induced from chronic oxytocin administrations, particularly in pediatric populations.

OBJECTIVE

We aimed to examine the impact of a 4-week course of intranasal oxytocin on amygdala functional connectivity in children with autism, compared to placebo. Additionally, we investigated whether oxytocin improves cardiac autonomic arousal, as indexed by high-frequency heart rate variability.

METHODS

Fifty-seven children with autism aged 8-12 years (45 boys, 12 girls) participated in a double-blind, randomized pharmaco-neuroimaging trial involving twice-daily administrations of intranasal oxytocin or placebo. Resting-state fMRI scans and simultaneous, in-scanner heart rate recordings were obtained before, immediately after, and 4 weeks after the nasal spray administration period.

RESULTS

Significant reductions in intrinsic amygdala-orbitofrontal connectivity were observed, particularly at the 4-week follow-up session. These reductions were correlated with improved social symptoms and lower cardiac autonomic arousal. Further, oxytocin's neural and cardiac autonomic effects were modulated by epigenetic modifications of the oxytocin receptor gene. The effects were more pronounced in children with reduced epigenetic methylation, signifying heightened expression of the oxytocin receptor.

CONCLUSION

These findings underscore that a 4-week oxytocin administration course decreases amygdala connectivity and improves cardiac autonomic balance. Epigenetic modulators may explain inter-individual variation in responses to oxytocin.

Long-Term Outcomes Following Fairly Brief Androgen Suppression and Stereotactic Radiation Therapy in High-Risk Prostate Cancer: Update from the FASTR/FASTR-2 Trials

PURPOSE/OBJECTIVE(S)

There has been emerging interest in the role of ultra-hypofractionated radiotherapy for high-risk prostate cancer, especially given its low α/β ratio. However, there is limited data on the long-term outcomes of this treatment strategy. The FASTR and FASTR-2 clinical trials were designed to assess the tolerability of stereotactic ablative body radiotherapy (SABR) in high-risk prostate cancer. FASTR was discontinued early due to unacceptable acute toxicity, whereas the acute toxicities in FASTR-2 were minimal. Herein, the long-term results from these trials are reported.

MATERIALS/METHODS

Eligible patients had at least 1 high-risk feature as per the National Comprehensive Cancer Network criteria for high-risk prostate cancer, no evidence of metastatic disease, and either a score of 3+ on the Vulnerable Elderly Scale or declined standard therapy. A total of 19 patients from a single institution were enrolled on FASTR between 2011 and 2015. They received 40 Gy to the prostate and 25 Gy to the pelvic lymph nodes in 5 fractions delivered once weekly for 5 weeks, along with 1 year of androgen deprivation therapy (ADT). The excessive acute toxicity in FASTR prompted several modifications in FASTR-2, including the omission of nodal irradiation. A total of 30 patients from the same institution were enrolled on FASTR-2 between 2015 and 2017. They received 35 Gy to the prostate alone in 5 fractions delivered once weekly for 5 weeks, along with 18 months of ADT.

RESULTS

A total of 44 patients were eligible for analysis, 16 from FASTR and 28 from FASTR-2. Most patients were >70 years old (77%). High-risk features included Gleason score ≥8 (46%), T3-T4 disease (27%) and baseline PSA >20 (50%). With a median follow-up of 6.4 years, the cumulative incidence of grade ≥3 genitourinary/gastrointestinal toxicity was 50% among FASTR patients and 7% among FASTR-2 patients. At 5 years, the combined rates of biochemical failure-free survival, freedom from distant metastases, prostate cancer-specific survival and overall survival were 72%, 90%, 92% and 83%, respectively. A total of 12 patients (27%) required further treatment. No significant differences in clinical outcomes were noted between the FASTR and FASTR-2 cohorts.

CONCLUSION

SABR for high-risk prostate cancer is an attractive option for reducing treatment burden. Clinical outcomes and toxicity with the FASTR-2 protocol were comparable to conventionally-fractionated radiotherapy plus ADT. Larger prospective, randomized trials exploring the role of SABR with ADT in high-risk disease are necessary to better understand the efficacy and tolerability of this approach.

The Role of Radiotherapy in Patients with Refractory Hodgkin Lymphoma after Brentuximab Vedotin and -/or Immune Checkpoint Inhibitors

PURPOSE/OBJECTIVE(S)

Brentuximab vedotin (BV) and immune checkpoint inhibitors (ICIs) had important roles in the treatment of relapse or refractory (R/R) Hodgkin lymphoma (HL). Treatment of refractory disease after BV and -/or ICIs remains a challenge. This study was conducted to evaluate the efficacy and safety of radiotherapy for R/R HL after failure to BV or ICIs.

MATERIALS/METHODS

We retrospectively analyzed patients in two institutions with R/R HL who had failed after first-line therapy, and were refractory to BV or ICIs, and received radiotherapy (RT) thereafter. The overall response rate (ORR), duration of response (DOR), progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

A total of 19 patients were enrolled. First-line systemic therapy consisted of ABVD (84.2%), AVD + ICIs (10.5%) and BEACOPP (5.3%), respectively. After first-line therapy, 15 patients (78.9%) were refractory, and 4 patients (21.1%) relapsed. After diagnosis of R/R HL, 8 patients (42.1%) received BV, and 17 patients (89.5%) received ICIs. RT was delivered in all 19 patients who failed after BV or ICIs. In 16 efficacy-evaluable patients, the ORR and CR rate were 100% and 100%. The median DOR was 17.2 months (range, 7.9 to 46.7 months). 3 patients progressed at outside of the radiation field. The in-field-response rate was 100%. The 12-month PFS and OS were 84.4% and 100%, respectively. No patients were reported with sever adverse events.

CONCLUSION

This study concluded that radiotherapy was effective and safe for refractory HL after BV or ICIs. Further prospective studies were warranted.

A blood-based metabolomic signature predictive of risk for pancreatic cancer

Emerging evidence implicates microbiome involvement in the development of pancreatic cancer (PaCa). Here, we investigate whether increases in circulating microbial-related metabolites associate with PaCa risk by applying metabolomics profiling to 172 sera collected within 5 years prior to PaCa diagnosis and 863 matched non-subject sera from participants in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cohort. We develop a three-marker microbial-related metabolite panel to assess 5-year risk of PaCa. The addition of five non-microbial metabolites further improves 5-year risk prediction of PaCa. The combined metabolite panel complements CA19-9, and individuals with a combined metabolite panel + CA19-9 score in the top 2.5th percentile have absolute 5-year risk estimates of >13%. The risk prediction model based on circulating microbial and non-microbial metabolites provides a potential tool to identify individuals at high risk of PaCa that would benefit from surveillance and/or from potential cancer interception strategies.

Patterns of Oncogene Coexpression at Single-Cell Resolution Influence Survival in Lymphoma

Cancers often overexpress multiple clinically relevant oncogenes, but it is not known if combinations of oncogenes in cellular subpopulations within a cancer influence clinical outcomes. Using quantitative multispectral imaging of the prognostically relevant oncogenes MYC, BCL2, and BCL6 in diffuse large B-cell lymphoma (DLBCL), we show that the percentage of cells with a unique combination MYC+BCL2+BCL6- (M+2+6-) consistently predicts survival across four independent cohorts (n = 449), an effect not observed with other combinations including M+2+6+. We show that the M+2+6- percentage can be mathematically derived from quantitative measurements of the individual oncogenes and correlates with survival in IHC (n = 316) and gene expression (n = 2,521) datasets. Comparative bulk/single-cell transcriptomic analyses of DLBCL samples and MYC/BCL2/BCL6-transformed primary B cells identify molecular features, including cyclin D2 and PI3K/AKT as candidate regulators of M+2+6- unfavorable biology. Similar analyses evaluating oncogenic combinations at single-cell resolution in other cancers may facilitate an understanding of cancer evolution and therapy resistance.

SIGNIFICANCE

Using single-cell-resolved multiplexed imaging, we show that selected subpopulations of cells expressing specific combinations of oncogenes influence clinical outcomes in lymphoma. We describe a probabilistic metric for the estimation of cellular oncogenic coexpression from IHC or bulk transcriptomes, with possible implications for prognostication and therapeutic target discovery in cancer. This article is highlighted in the In This Issue feature, p. 1027.

Effects of multiple-dose intranasal oxytocin administration on social responsiveness in children with autism: a randomized, placebo-controlled trial

BACKGROUND

Intranasal administration of oxytocin is increasingly explored as a new approach to facilitate social development and reduce disability associated with a diagnosis of autism spectrum disorder (ASD). The efficacy of multiple-dose oxytocin administration in children with ASD is, however, not well established.

METHODS

A double-blind, randomized, placebo-controlled trial with parallel design explored the effects of a 4-week intranasal oxytocin administration (12 IU, twice daily) on parent-rated social responsiveness (Social Responsiveness Scale: SRS-2) in pre-pubertal school-aged children (aged 8-12 years, 61 boys, 16 girls). Secondary outcomes included a questionnaire-based assessment of repetitive behaviors, anxiety, and attachment. Effects of oxytocin were assessed immediately after the administration period and at a follow-up, 4 weeks after the last administration. The double-blind phase was followed by a 4-week single-blind phase during which all participants received intranasal oxytocin.

RESULTS

In the double-blind phase, both the oxytocin and placebo group displayed significant pre-to-post-improvements in social responsiveness and secondary questionnaires, but improvements were not specific to the intranasal oxytocin. Notably, in the single-blind phase, participants who were first allocated to intranasal placebo and later changed to intranasal oxytocin displayed a significant improvement in social responsiveness, over and above the placebo-induced improvements noted in the first phase. Participants receiving oxytocin in the first phase also showed a significant further improvement upon receiving a second course of oxytocin, but only at the 4-week follow-up. Further, exploratory moderator analyses indicated that children who received psychosocial trainings (3 or more sessions per month) along with oxytocin administration displayed a more pronounced improvement in social responsiveness.

LIMITATIONS

Future studies using larger cohorts and more explicitly controlled concurrent psychosocial trainings are warranted to further explore the preliminary moderator effects, also including understudied populations within the autism spectrum, such as children with co-occurring intellectual disabilities.

CONCLUSIONS

Four weeks of oxytocin administration did not induce treatment-specific improvements in social responsiveness in school-aged children with ASD. Future studies are warranted to further explore the clinical efficacy of oxytocin administration paired with targeted psychosocial trainings that stimulate socio-communicative behaviors. Trial registration The trial was registered with the European Clinical Trial Registry (EudraCT 2018-000769-35) on June 7th, 2018 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2018-000769-35/BE ).

[Type III secretory protein SINC of Chlamydia psittaci promotes host cell autophagy by activating the MAPK/ERK signaling pathway]

OBJECTIVE

To investigate the effects of SINC, a secreted protein of Chlamydia psittaci, on autophagy of host cells and the role of MAPK/ERK signaling pathway in mediating SINC-induced autophagy.

METHODS

RAW 264.7 cells treated with recombinant SINC were examined for changes in expression levels of LC3-II, Beclin-1, phosphorylated and total ERK1/2 using Western blotting. The expression level of LC3 in the treated cells was detected using immunofluorescence analysis, and the formation of autophagosomes and autolysosomes was observed with transmission electron microscopy (TEM). The effect of pretreatment with U0126 (a specific ERK inhibitor) on the expression levels of LC3-II and Beclin-1 in RAW 264.7 cells exposed to different concentrations of SINC was examined using Western blotting, and LC3 puncta in the cells was detected with immunofluorescence analysis.

RESULTS

The expression levels of LC3-II and Beclin-1 were the highest in RAW 264.7 cells treated with 2 μg/mL SINC for 12h. Immunofluorescence analysis showed exposure to SINC significantly increased the number of cells containing LC3 puncta, where the presence of autophagosomes and autolysosomes was detected. Exposure to 2 μg/mL SINC for 15 min resulted in the most significant increase of the ratios of p-ERK1/2/ERK1/2 in RAW 264.7 cells. Pretreatment of the cells with U0126 prior to SINC exposure significantly decreased the ratio of p-ERK1/2/ERK1/2, lowered the expression levels of LC3-II and Beclin-1, and decreased LC3 aggregation in the cells.

CONCLUSIONS

SINC exposure can induce autophagy in RAW 264.7 cells by activating the MAPK/ERK signaling pathway.

Uniaxial cyclic stretch enhances osteogenic differentiation of OPLL-derived primary cells via YAP-Wnt/β-catenin axis

The pathogenesis of posterior longitudinal ligament ossification (OPLL) remains inadequately understood. Mechanical stimulation is one of the important pathogenic factors in OPLL. As one of the mechanical stimulation transduction signals, the yes-associated protein (YAP) interacts with the Wnt/β-catenin signalling pathway, which plays an important role in osteogenic differentiation. This study aimed to demonstrate the role of YAP-Wnt/β-catenin axis in cell differentiation induced by mechanical stress. Primary cells extracted from posterior longitudinal ligament tissues from OPLL or non-OPLL patients were subjected to sinusoidal uniaxial cyclic stretch (5 %, 0.5 Hz, 3 d). The expression of runt-related transcription factor 2, collagen I, osterix, osteocalcin and alkaline phosphatase were compared between the static and the experimental groups. In addition, the cytoskeleton was detected using phalloidin staining while YAP phosphorylation states and nuclear location were identified using immunofluorescence. The results showed that mechanical stretching loading increased the expression of osteogenic genes and proteins in the OPLL group, while it had no significant effect on the control group. When OPLL cells were stretched, YAP exhibited an obvious nuclear translocation and the Wnt/β-catenin pathway was activated. Knocking down YAP or β-catenin could weaken the impact upon osteogenic differentiation induced by mechanical stimulation. YAP-mediated mechanical stimulation promoted osteogenic differentiation of OPLL cells through Wnt/β-catenin pathway and this progress was independent of the Hippo pathway.

Abstract P076: Contribution of the microbiome to a metabolomic signature predictive of risk for pancreatic cancer

Purpose: Emerging evidence implicates the microbiome in the development of pancreatic cancer. We investigated whether increased levels of microbial-related metabolites in circulation are associated with pancreatic cancer risk. Methods: We applied metabolomics profiling to sera from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cohort to quantify and build a model based on 14 microbial-related metabolites. The study involved samples collected from 172 subjects within five years prior to diagnosis and 863 matched controls. Data from five PLCO centers were used for training and from two centers for validation and model selection. The model was subsequently tested using samples from three independent centers. The contributions of non-microbial-associated metabolites as well as CA19-9 was also assessed. Results: A 3-marker microbial-related metabolite panel yielded in the PLCO testing set an AUC of 0.64 (95% CI: 0.53-0.76) for 5-year probability of pancreatic cancer. Five additional non-microbial metabolites were identified that when combined with the microbiome panel yielded an AUC of 0.79 (95% CI: 0.71-0.88) for 5-year probability of pancreatic cancer in the PLCO testing set. The combined metabolite panel and CA19-9 yielded an AUC of 0.86 (95% CI: 0.77-0.95) for 2-year probability of pancreatic cancer in the PLCO testing set, which was improved compared to CA19-9 alone (AUC: 0.70 (95% CI: 0.57-0.82), p&lt; 0.001). Conclusion: We developed a metabolite panel derived in part from the microbiome for risk assessment of pancreatic cancer, which has relevance to prevention and early detection.

Citation Format: Johannes F. Fahrmann, Ehsan Irajizad, Ana Kenney, Tiffany Tang, Jody Vykoukal, Ranran Wu, Jennifer B. Dennison, Marta Sans Escofet, James P. Long, Maureen Loftus, John A. Chabot, Michael D. Kluger, Fay Kastrinos, Lauren Brais, Ana Babic, Kunal Jajoo, Linda S. Lee, Thomas E. Clancy, Kimmie Ng, Andrea Bullock, Jeanine M. Genkinger, Anirban Maitra, Kim-Anh Do, Bin Yu, Brian M. Wolpin, Samir Hanash. Contribution of the microbiome to a metabolomic signature predictive of risk for pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P076.

An ex vivo platform to guide drug combination treatment in relapsed/refractory lymphoma

Although combination therapy is the standard of care for relapsed/refractory non-Hodgkin's lymphoma (RR-NHL), combination treatment chosen for an individual patient is empirical, and response rates remain poor in individuals with chemotherapy-resistant disease. Here, we evaluate an experimental-analytic method, quadratic phenotypic optimization platform (QPOP), for prediction of patient-specific drug combination efficacy from a limited quantity of biopsied tumor samples. In this prospective study, we enrolled 71 patients with RR-NHL (39 B cell NHL and 32 NK/T cell NHL) with a median of two prior lines of treatment, at two academic hospitals in Singapore from November 2017 to August 2021. Fresh biopsies underwent ex vivo testing using a panel of 12 drugs with known efficacy against NHL to identify effective single and combination treatments. Individualized QPOP reports were generated for 67 of 75 patient samples, with a median turnaround time of 6 days from sample collection to report generation. Doublet drug combinations containing copanlisib or romidepsin were most effective against B cell NHL and NK/T cell NHL samples, respectively. Off-label QPOP-guided therapy offered at physician discretion in the absence of standard options (n = 17) resulted in five complete responses. Among patients with more than two prior lines of therapy, the rates of progressive disease were lower with QPOP-guided treatments than with conventional chemotherapy. Overall, this study shows that the identification of patient-specific drug combinations through ex vivo analysis was achievable for RR-NHL in a clinically applicable time frame. These data provide the basis for a prospective clinical trial evaluating ex vivo-guided combination therapy in RR-NHL.

Spike Protein Cleavage-Activation in the Context of the SARS-CoV-2 P681R Mutation: an Analysis from Its First Appearance in Lineage A.23.1 Identified in Uganda

Based on its predicted ability to affect transmissibility and pathogenesis, surveillance studies have highlighted the role of a specific mutation (P681R) in the S1/S2 furin cleavage site of the SARS-CoV-2 spike protein. Here we analyzed A.23.1, first identified in Uganda, as a P681R-containing virus several months prior to the emergence of B.1.617.2 (Delta variant). We performed assays using peptides mimicking the S1/S2 from A.23.1 and B.1.617 and observed significantly increased cleavability with furin compared to both an original B lineage (Wuhan-Hu1) and B.1.1.7 (Alpha variant). We also performed cell-cell fusion and functional infectivity assays using pseudotyped particles and observed an increase in activity for A.23.1 compared to an original B lineage spike. However, these changes in activity were not reproduced in the B lineage spike bearing only the P681R substitution. Our findings suggest that while A.23.1 has increased furin-mediated cleavage linked to the P681R substitution, this substitution needs to occur on the background of other spike protein changes to enable its functional consequences. IMPORTANCE During the course of the SARS-CoV-2 pandemic, viral variants have emerged that often contain notable mutations in the spike gene. Mutations that encode changes in the spike S1/S2 (furin) activation site have been considered especially impactful. The S1/S2 change from proline to arginine at position 681 (P681R) first emerged in the A.23.1 variant in Uganda, and subsequently occurred in the more widely transmitted Delta variant. We show that the A.23.1 spike is more readily activated by the host cell protease furin, but that this is not reproduced in an original SARS-CoV-2 spike containing the P681R mutation. Changes to the S1/S2 (furin) activation site play a role in SARS-CoV-2 infection and spread, but successful viruses combine these mutations with other less well identified changes, occurring as part of natural selection.

[Research advances on the application of carbon dots in wound treatment]

Chronic and infectious wound healing has always been an issue of concern in clinical and scientific research, in which bacterial infection and oxidative damage are the key factors hindering wound healing. Carbon dots, as a new material, has attracted much attention because of its unique physical and chemical properties and good biological safety. In recent years, the researches on the antibacterial property, antioxidant, and photoluminescence properties of carbon dots are more and more extensive and carbon dots have great potential in the treatment of chronic and infectious wounds. This paper reviews the research progress of carbon dots in three aspects: antibacterial, anti-oxidation and monitoring of wound infection are reviewed, and further discusses its specific mechanism, potential research direction, and application prospect.

Evidence of a Near-Threshold Resonance in ^{11}B Relevant to the β-Delayed Proton Emission of ^{11}Be

A narrow near-threshold proton-emitting resonance (E_{x}=11.4  MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4  keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the β-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11  keV) emission channels.

A genomic-augmented multivariate prognostic model for the survival of Natural-killer/T-cell lymphoma patients from an international cohort

With lowering costs of sequencing and genetic profiling techniques, genetic drivers can now be detected readily in tumors but current prognostic models for Natural-killer/T cell lymphoma (NKTCL) have yet to fully leverage on them for prognosticating patients. Here, we used next-generation sequencing to sequence 260 NKTCL tumors, and trained a genomic prognostic model (GPM) with the genomic mutations and survival data from this retrospective cohort of patients using LASSO Cox regression. The GPM is defined by the mutational status of 13 prognostic genes and is weakly correlated with the risk-features in International Prognostic Index (IPI), Prognostic Index for Natural-Killer cell lymphoma (PINK) and PINK-Epstein-Barr virus (PINK-E). Cox-proportional hazard multivariate regression also showed that the new GPM is independent and significant for both progression-free survival (PFS, HR: 3.73, 95% CI 2.07-6.73; P<0.001) and overall survival (OS, HR: 5.23, 95% CI 2.57-10.65; P=0.001) with known risk-features of these indices. When we assign an additional risk-score to samples, which are mutant for the GPM, the Harrell's C-indices of GPM-augmented IPI, PINK and PINK-E improved significantly (P<0.001, χ² test) for both PFS and OS. Thus, we report on how genomic mutational information could steer towards better prognostication of NKTCL patients. This article is protected by copyright. All rights reserved.

Treatment outcomes of T and natural-killer/T-cell lymphoma with ifosfamide, carboplatin and etoposide chemotherapy

BACKGROUND

Contemporary data of peripheral T-cell lymphoma (PTCL) and natural-killer/T-cell lymphoma (NKTL) patients treated with ifosfamide, carboplatin and etoposide (ICE) are limited.

AIMS

We performed a retrospective analysis to estimate outcomes of ICE-treated PTCL and NKTL patients at three tertiary cancer centres in Singapore.

METHODS AND RESULTS

Patients were identified through lymphoma databases from National Cancer Centre Singapore (NCCS), National University Hospital, Singapore (NUHS), and Singapore General Hospital (SGH). Responses and survival outcomes were determined from electronic medical records. A total of 75 patients with a median age of 50 were included. ICE was used as first-line treatment in 14 patients (19%) and as subsequent lines of treatment in 61 patients (81%). The overall response rates (ORR) for all patients was 63% (40% complete response [CR]). The ORR and CR in the first line were 86% and 64% respectively. At a median follow-up duration of 71.0 months, the median progression-free (PFS) and overall survival (OS) for all patients were 4.4 months (95%CI, 2.7-6.0) and 16 months (95%CI, 8.3-45.4) respectively.

CONCLUSION

In summary, ICE showed high ORR but poor PFS in relapsed/refractory PTCL and NKTL. ORR of ICE in the first line setting appears better than real-world CHOP data and warrants further study.

A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies

Purpose:

This phase 1 study aims to evaluate the tolerability and the recommended phase 2 dose of selinexor in Asian patients with advanced or metastatic malignancies.

Experimental Design:

A total of 105 patients with advanced malignancies were enrolled from two sites in Singapore (National University Hospital and the National Cancer Centre, Singapore) from 24 February 2014 to 14 January 2019. We investigated four dosing schedules of selinexor in a 3 + 3 dose escalation design with an additional Phase 1b expansion cohort. Adverse events were graded with the NCI Common Terminology Criteria for Adverse Events v 4.03. Pharmacodynamic assessments included nuclear cytoplasmic localization of p27, XPO1 cargo proteins pre and post selinexor dosing and pharmacokinetic assessments were conducted at doses between 40 and 60 mg/m².

Results:

In our Asian patient cohort, dosing at 40 mg/m² given 2 out of 3 weeks, was the most tolerable for our patients. At this dose level, grade 3 adverse events included fatigue (8%), hyponatremia (23%), vomiting (5%), thrombocytopenia (5%), and anaemia (2%). Selinexor had a rapid oral absorption with median T_max of 2 h and no PK accumulation after multiple doses of tested regimens. Complete responses were seen in two lymphoma patients. Partial responses were noted in three diffuse large B cell lymphomas, one Hodgkin’s lymphoma and thymic carcinoma patient, respectively.

Conclusion:

Selinexor is tolerated by Asian patients at 40 mg/m² twice a week given 2 out of 3 weeks. A 1-week drug holiday was needed as our patients could not tolerate the current approved continuous dosing regimens because of persistent grade 3 fatigue, anorexia and hyponatremia.

Spike protein cleavage-activation mediated by the SARS-CoV-2 P681R mutation: a case-study from its first appearance in variant of interest (VOI) A.23.1 identified in Uganda

The African continent like all other parts of the world with high infection/low vaccination rates can, and will, be a source of novel SARS-CoV-2 variants. The A.23 viral lineage, characterized by three spike mutations F157L, V367F and Q613H, was first identified in COVID-19 cases from a Ugandan prison in July 2020, and then was identified in the general population with additional spike mutations (R102I, L141F, E484K and P681R) to comprise lineage A.23.1 by September 2020, with this virus being designated a variant of interest (VOI) in Africa and with subsequent spread to 26 other countries. The P681R spike substitution of the A.23.1 VOI is of note as it increases the number of basic residues in the sub-optimal SARS-CoV-2 spike protein furin cleavage site; as such, this substitution may affect viral replication, transmissibility or pathogenic properties. The same P681R substitution has also appeared in B.1.617 variants, including B.1.617.2 (Delta). Here, we performed assays using fluorogenic peptides mimicking the S1/S2 sequence from A.23.1 and B.1.617.2 and observed significantly increased cleavability with furin, compared to sequences derived from the original Wuhan-Hu1 S1/S2. We performed functional infectivity assays using pseudotyped MLV particles harboring SARS-CoV-2 spike proteins and observed an increase in transduction for A.23.1-pseudotyped particles compared to Wuhan-Hu-1 in Vero-TMPRSS2 and Calu-3 cells (with a presumed early entry pathway), although lowered infection in Vero E6 cells (with a presumed late entry pathway). However, these changes in infectivity were not reproduced in the original Wuhan-Hu-1 spike bearing only the P681R substitution. Our findings suggest that while A.23.1 has increased furin-mediated cleavage linked to the P681R substitution, which may affect viral infection and transmissibility, this substitution alone is not sufficient and needs to occur on the background of other spike protein changes to enable its full functional consequences.

Functional evaluation of the P681H mutation on the proteolytic activation of the SARS-CoV-2 variant B.1.1.7 (Alpha) spike

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent causing the COVID-19 pandemic. SARS-CoV-2 B.1.1.7 (Alpha), a WHO variant of concern first identified in the United Kingdom in late 2020, contains several mutations including P681H in the spike S1/S2 cleavage site, which is predicted to increase cleavage by furin, potentially impacting the viral cell entry. Here, we studied the role of the P681H mutation in B.1.1.7 cell entry. We performed assays using fluorogenic peptides mimicking the Wuhan-Hu-1 and B.1.1.7 S1/S2 sequence and observed no significant difference in furin cleavage. Functional assays using pseudoparticles harboring SARS-CoV-2 spikes and cell-to-cell fusion assays demonstrated no differences between Wuhan-Hu-1, B.1.1.7, or a P681H point mutant. Likewise, we observed no differences in viral growth between USA-WA1/2020 and a B.1.1.7 isolate in cell culture. Our findings suggest that, although the B.1.1.7 P681H mutation may slightly increase S1/S2 cleavage, this does not significantly impact viral entry or cell-cell spread.

Functional Infectious Nanoparticle Detector: Finding Viruses by Detecting Their Host Entry Functions Using Organic Bioelectronic Devices

Emerging viruses will continue to be a threat to human health and wellbeing into the foreseeable future. The COVID-19 pandemic revealed the necessity for rapid viral sensing and inhibitor screening in mitigating viral spread and impact. Here, we present a platform that uses a label-free electronic readout as well as a dual capability of optical (fluorescence) readout to sense the ability of a virus to bind and fuse with a host cell membrane, thereby sensing viral entry. This approach introduces a hitherto unseen level of specificity by distinguishing fusion-competent viruses from fusion-incompetent viruses. The ability to discern between competent and incompetent viruses means that this device could also be used for applications beyond detection, such as screening antiviral compounds for their ability to block virus entry mechanisms. Using optical means, we first demonstrate the ability to recapitulate the entry processes of influenza virus using a biomembrane containing the viral receptor that has been functionalized on a transparent organic bioelectronic device. Next, we detect virus membrane fusion, using the same, label-free devices. Using both reconstituted and native cell membranes as materials to functionalize organic bioelectronic devices, configured as electrodes and transistors, we measure changes in membrane properties when virus fusion is triggered by a pH drop, inducing hemagglutinin to undergo a conformational change that leads to membrane fusion.

Functional evaluation of the P681H mutation on the proteolytic activation the SARS-CoV-2 variant B.1.1.7 (Alpha) spike

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent causing the COVID-19 pandemic. SARS-CoV-2 B.1.1.7 (Alpha), a WHO variant of concern (VOC) first identified in the UK in late 2020, contains several mutations including P681H in the spike S1/S2 cleavage site, which is predicted to increase cleavage by furin, potentially impacting the viral cell entry. Here, we studied the role of the P681H mutation in B.1.1.7 cell entry. We performed assays using fluorogenic peptides mimicking the Wuhan-Hu-1 and B.1.1.7 S1/S2 sequence and observed no significant difference in furin cleavage. Functional assays using pseudoparticles harboring SARS-CoV-2 spikes and cell-to-cell fusion assays demonstrated no differences between Wuhan-Hu-1, B.1.1.7 or a P681H point mutant. Likewise, we observed no differences in viral growth between USA-WA1/2020 and a B.1.1.7 isolate in cell culture. Our findings suggest that while the B.1.1.7 P681H mutation may slightly increase S1/S2 cleavage this does not significantly impact viral entry or cell-cell spread.

Association between isolated diastolic hypertension and cardiovascular events: a systematic review and meta-analysis of prospective cohorts

Background

Isolated diastolic hypertension (IDH) is a subtype of hypertension, which is defined as systolic blood pressure (SBP) &lt;140 mmHg and diastolic blood pressure (DBP) ≥90 mmHg by 2018 European Society of Cardiology (ESC) guideline and 2019 National Institute for Health and Care Excellent (NICE). Whereas some previous studies have demonstrated the significant association between IDH and cardiovascular (CV) events, some have not.

Purpose

To assess the association between IDH and the risk of CV events, CV mortality, and all-cause mortality.

Methods

We conducted a systematic search for publications using Medline, Embase, and the Cochrane Library from inception through March 2021 for prospective cohort studies exploring the association between IDH and CV events, CV mortality, and all-cause mortality. Relative risks (RR) or hazard ratios were extracted from the selected studies. Random effect models with inverse variance weighting were used to calculate the pooled RR and 95% confidence interval (CI). The primary outcome was a composite of total CV events including CV mortality. The secondary outcomes were CV mortality and all-cause mortality. We defined the IDH as SBP &lt;140 mmHg and DBP ≥90 mmHg, reference group as BP less than 140/90mmHg.

Results

Overall, 15 studies were identified including 1049587 participants (5.5% IDH). For the primary outcome, IDH was significantly associated with risk of CV events (RR, 1.40 [95% CI, 1.18–1.66], p&lt;0.001). The increased risk of CV events was also observed in subgroup analyses based on age (less or more than 50) and sex. However, in further stratified analysis based on geographical region, only the Asia population showed a significant association with increased risk of CV events, whereas results were null in Europe and North America populations. For the secondary outcomes, IDH was significantly associated with increased CV mortality (RR [95% CI], 1.41 [1.12–1.78], p&lt;0.001) but not with all-cause mortality (RR [95% CI], 1.13 [0.86–1.48], p=0.378). The sensitivity analysis showed the overall results did not vary significantly after exclusion of any one study.

Conclusions

IDH is associated with increased risk of CV events and CV mortality. Further, more large-scale prospective epidemiological cohorts are needed to confirm our conclusion.

Funding Acknowledgement

Type of funding sources: None. Primary outcomeSecondary outcomes

Inhibitors of L-Type Calcium Channels Show Therapeutic Potential for Treating SARS-CoV-2 Infections by Preventing Virus Entry and Spread

COVID-19 is caused by a novel coronavirus, the severe acute respiratory syndrome coronavirus (CoV)-2 (SARS-CoV-2). The virus is responsible for an ongoing pandemic and concomitant public health crisis around the world. While vaccine development is proving to be highly successful, parallel drug development approaches are also critical in the response to SARS-CoV-2 and other emerging viruses. Coronaviruses require Ca2+ ions for host cell entry, and we have previously shown that Ca2+ modulates the interaction of the viral fusion peptide with host cell membranes. In an attempt to accelerate drug repurposing, we tested a panel of L-type calcium channel blocker (CCB) drugs currently developed for other conditions to determine whether they would inhibit SARS-CoV-2 infection in cell culture. All the CCBs tested showed varying degrees of inhibition, with felodipine and nifedipine strongly limiting SARS-CoV-2 entry and infection in epithelial lung cells at concentrations where cell toxicity was minimal. Further studies with pseudotyped particles displaying the SARS-CoV-2 spike protein suggested that inhibition occurs at the level of virus entry. Overall, our data suggest that certain CCBs have the potential to treat SARS-CoV-2 infections and are worthy of further examination for possible treatment of COVID-19.

Effects of miR-195 on diabetic nephropathy rats through targeting TLR4 and blocking NF-κB pathway

OBJECTIVE

The aim of this study was to explore the effects of micro ribonucleic acid (miR)-195 on diabetic nephropathy (DN) rats through targeting Toll-like receptor 4 (TLR4) and inhibiting the nuclear factor-κB (NF-κB) signaling pathway.

MATERIALS AND METHODS

The model of DN was first successfully established in rats. All rats were randomly divided into six groups, including control group (n=20), model group (n=20), 25 nM miR-195 mimics group (25 nM M group, n=20), 50 nM M group (n=20), 25 nM miR-195 inhibitor group (25 nM I group, n=20), and 50 nM I group (n=20). Urine volume, proteins and inflammatory factors were detected in each group, respectively. Subsequently, macrophages were cultured and transfected in vitro. The mRNA expressions of miR-195 and TLR4 in control group and model groups were determined using fluorescence quantitative polymerase chain reaction (qPCR). The protein expressions of TLR4 and NF-κB in macrophages were determined using Western blotting. Furthermore, the proliferation of macrophages was detected via cell counting kit-8 (CCK-8) assay.

RESULTS

Compared with model group, 24-h urine volume, urine protein, creatinine, urea nitrogen, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 levels declined significantly in 25 nM M group and 50 nM M group (p<0.05). However, they increased significantly in 25 nM I group and 50 nM I group (p<0.05). It could be suggested that miR-195 mimics might relieve the symptoms of DN rats. In kidney tissues in DN, miR-195 was lowly expressed, whereas TLR4 was highly expressed (p<0.01). This suggested that there was a negative correlation between the mRNA expressions of miR-195 and TLR4 (r2=0.4836, p=0.0007). After overexpression of miR-195, the protein expression of TLR4 was significantly reduced (p<0.01), indicating that miR-195 could negatively regulate the protein expression of TLR4. Besides, the protein expressions of TLR4 and NF-κB in si-TLR4 group were evidently lower than those in NC group (p<0.01). Meanwhile, they also had significant differences in si-TLR4 group compared with si-TLR4 + miR-195 inhibitor group (p<0.05). The above results demonstrated that the protein expressions of TLR4 and NF-κB in macrophages could be markedly inhibited by si-TLR4, but be promoted by si-TLR4 + miR-195 inhibitor. CCK-8 assay demonstrated that the proliferation ability of macrophages was remarkably weaker in miR-195 mimics group than NC group (p<0.001). Furthermore, it was also significantly weaker in si-TLR4 + miR-195 inhibitor group than si-TLR4 group (p<0.05).

CONCLUSIONS

MiR-195 reduces the release of inflammatory factors and inhibits the proliferation of macrophages through targeting TLR4 and blocking the NF-κB pathway, thereby alleviating the symptoms of DN rats.

Clinical and economic evaluation of a surveillance protocol to manage hepatitis B virus (HBV) reactivation among lymphoma patients with resolved HBV infection receiving rituximab

STUDY OBJECTIVE

To evaluate a surveillance protocol in managing the risk of hepatitis B virus (HBV) reactivation among lymphoma patients with resolved HBV infection receiving rituximab.

DESIGN

Prospective, single-arm study.

SETTING

National Cancer Centre, Singapore.

PATIENTS

Lymphoma patients with resolved HBV infection and scheduled to receive rituximab-based treatment.

INTERVENTION

Close monitoring of HBV DNA levels, ie. every 4-6 weeks during rituximab treatment, every 6-8 weeks in the first year post-treatment, and every 3-4 months in the second year post-treatment.

MEASUREMENTS

The efficacy of the surveillance protocol was examined by evaluating the rates of reactivation-related events. Feasibility was evaluated based on patient adherence. An economic analysis using a cost-minimization approach was conducted to compare the costs between the surveillance protocol and universal prophylaxis with entecavir 0.5 mg daily up to 1 year after cessation of rituximab.

MAIN RESULTS

A total of 66 patients provided analyzable data with a follow-up period of 966.6 months. No hepatitis flare or reactivation-related events were detected. The median adherence rate to the surveillance protocol was 90.5%. Cost savings of US$946.40 per patient over the entire surveillance period were achieved if the surveillance protocol was adopted and was most affected by changes in prophylaxis duration and the cost of antiviral prophylaxis.

CONCLUSIONS

The surveillance protocol is an effective, feasible and cost-saving strategy to manage HBV reactivation among lymphoma patients with resolved HBV infection receiving rituximab.

Nonequilibrium pattern formation in circularly confined two-dimensional systems with competing interactions

We numerically investigate the nonequilibrium behaviors of classic particles with competing interactions confined in a two-dimensional logarithmic trap. We reveal a quench-induced surprising dynamics exhibiting rich dynamic patterns depending upon confinement strength and trap size, which is attributed to the time-dependent competition between interparticle repulsions and attractions under a circular confinement. Moreover, in the collectively diffusive motions of the particles, we find that the emergence of dynamic structure transformation coincides with a diffusive mode transition from superdiffusion to subdiffusion. These findings are likely useful in understanding the pattern selection and evolution in various chemical and biological systems in addition to modulated systems, and add a new route to tailoring the morphology of pattern-forming systems.

Proteolytic Activation of SARS-CoV-2 Spike at the S1/S2 Boundary: Potential Role of Proteases beyond Furin

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses its spike (S) protein to mediate viral entry into host cells. Cleavage of the S protein at the S1/S2 and/or S2' site(s) is associated with viral entry, which can occur at either the cell plasma membrane (early pathway) or the endosomal membrane (late pathway), depending on the cell type. Previous studies show that SARS-CoV-2 has a unique insert at the S1/S2 site that can be cleaved by furin, which appears to expand viral tropism to cells with suitable protease and receptor expression. Here, we utilize viral pseudoparticles and protease inhibitors to study the impact of the S1/S2 cleavage on infectivity. Our results demonstrate that S1/S2 cleavage is essential for early pathway entry into Calu-3 cells, a model lung epithelial cell line, but not for late pathway entry into Vero E6 cells, a model cell line. The S1/S2 cleavage was found to be processed by other proteases beyond furin. Using bioinformatic tools, we also analyze the presence of a furin S1/S2 site in related CoVs and offer thoughts on the origin of the insertion of the furin-like cleavage site in SARS-CoV-2.

In Xenopus ependymal cilia drive embryonic CSF circulation and brain development independently of cardiac pulsatile forces

BACKGROUND

Hydrocephalus, the pathological expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles, is a common, deadly disease. In the adult, cardiac and respiratory forces are the main drivers of CSF flow within the brain ventricular system to remove waste and deliver nutrients. In contrast, the mechanics and functions of CSF circulation in the embryonic brain are poorly understood. This is primarily due to the lack of model systems and imaging technology to study these early time points. Here, we studied embryos of the vertebrate Xenopus with optical coherence tomography (OCT) imaging to investigate in vivo ventricular and neural development during the onset of CSF circulation.

METHODS

Optical coherence tomography (OCT), a cross-sectional imaging modality, was used to study developing Xenopus tadpole brains and to dynamically detect in vivo ventricular morphology and CSF circulation in real-time, at micrometer resolution. The effects of immobilizing cilia and cardiac ablation were investigated.

RESULTS

In Xenopus, using OCT imaging, we demonstrated that ventriculogenesis can be tracked throughout development until the beginning of metamorphosis. We found that during Xenopus embryogenesis, initially, CSF fills the primitive ventricular space and remains static, followed by the initiation of the cilia driven CSF circulation where ependymal cilia create a polarized CSF flow. No pulsatile flow was detected throughout these tailbud and early tadpole stages. As development progressed, despite the emergence of the choroid plexus in Xenopus, cardiac forces did not contribute to the CSF circulation, and ciliary flow remained the driver of the intercompartmental bidirectional flow as well as the near-wall flow. We finally showed that cilia driven flow is crucial for proper rostral development and regulated the spatial neural cell organization.

CONCLUSIONS

Our data support a paradigm in which Xenopus embryonic ventriculogenesis and rostral brain development are critically dependent on ependymal cilia-driven CSF flow currents that are generated independently of cardiac pulsatile forces. Our work suggests that the Xenopus ventricular system forms a complex cilia-driven CSF flow network which regulates neural cell organization. This work will redirect efforts to understand the molecular regulators of embryonic CSF flow by focusing attention on motile cilia rather than other forces relevant only to the adult.

Phase I study of selinexor in combination with dexamethasone, ifosfamide, carboplatin, etoposide chemotherapy in patients with relapsed or refractory peripheral T-cell or naturalkiller/T-cell lymphoma

Selinexor is a selective inhibitor of nuclear export with anti-cancer properties. We performed a phase I study to determine the safety and maximum tolerated dose of selinexor when combined with high-dose dexamethasone, ifosfamide, carboplatin and etoposide (DICE) in relapsed/refractory T-cell lymphoma (TCL) and natural-killer/T-cell lymphoma (NKTL). Patients with relapsed/refractory TCL and NKTL were treated with standard dose ICE, dexamethasone 20 mg on days 3 to 7, and escalating doses of oral selinexor on days 3, 5 and 7 in a 3+3 design. Dose levels (DL) 1, 2 and 3 were 40, 60 and 80 mg, respectively. Eleven patients with a median age of 60 years were enrolled; six at DL1 and five at DL2. Patients had received a median of two (range, 1-4) prior lines of treatment and seven had primary refractory disease at entry into the study. Patients received a median of three cycles (range, 1-6) of selinexor-DICE. The most common grade 1 or 2 toxicities included nausea (64%), fatigue (55%), and anorexia (45%) and the most common grade 3 or 4 toxicities included thrombocytopenia (82%), anemia (82%), neutropenia (73%), and hyponatremia (73%). Two patients developed dose-limiting toxicities at DL2 and one at DL1. Five patients discontinued treatment for reasons other than disease progression or lack of response. Of the ten evaluable patients, the overall and complete response rates were 91% and 82%, respectively. The maximum tolerated dose of selinexor was 40 mg when combined with DICE. The combination showed promising complete response rates in patients with relapsed/refractory TCL and NKTL but was poorly tolerated. (clinicaltrials. gov identifier: NCT03212937).

Abstract PO-35: Prognostic significance of MYC, BCL2, and BCL6 colocalization at single-cell resolution in DLBCL

MYC, BCL2, and BCL6 are commonly used markers for immunohistochemistry of Diffuse large B-cell lymphomas (DLBCL). Coexpression of MYC and BCL2 in particular constitutes a subgroup of “double expressor lymphomas” (DEL) with a distinct poor clinical outcome. However, it is not known if MYC and BCL2/BCL6 coexpression occurs in the same cell or in different cells within the tumor, as traditional immunohistochemistry (IHC) is limited by the number of markers that can be simultaneously assessed within formalin-fixed, paraffin-embedded (FFPE) samples. We set out to discover the clinical significance of MYC, BCL2, and BCL6 colocalization at single-cell resolution using multiplexed quantitative immunofluorescence (qIF) based on sequential OPAL-TSA staining and spectral microscopy on the Vectra platform. The initial discovery cohort comprised 90 cases of DLBCL from NUH Singapore with adequate clinical follow-up after R-CHOP therapy. We stratified each DLBCL tumor into 8 “clonal fractions” based on the possible permutations of MYC (M), BCL2 (2), and BCL6 (6) colocalization: M+2+6+, M+2+6-, M+2-6+, M+2-6-, M-2+6+, M-2-6+, M-2+6-, and M-2-6-. Interestingly, even within cases that fit traditional IHC criteria for “positivity” of MYC, BCL2, and BCL6, only a subset of cells within each case expressed multiple markers concurrently. Using the fraction of each of these clones as a continuous variable, Cox regression analysis revealed that the percentage of M+2+6- cells in a case was most predictive of poor survival. Importantly, the same clonal fraction (M+2+6-) was a significant poor prognostic feature in 2 smaller validation cohorts from SGH Singapore (n=41) and MD Anderson Cancer Centre USA (n=36). The single-cell staining pattern of these markers revealed a stark contrast between healthy tonsil tissue and DLBCL tissue. In the tonsil, colocalization of each marker was nonrandom (mutually exclusive BCL2 positivity in B cells outside the germinal center and BCL6 positivity inside the germinal center), whereas in DLBCL samples the mutual exclusivity pattern noted in the tonsil was lost, leading to a random distribution of colocalization of MYC, BCL2, and BCL6. The random nature of this colocalization allowed us to mathematically predict the “extent” of these 8 subclones from any data set with quantitative data of each single marker (MYC, BCL2, and BCL6). We therefore attempted to evaluate this model in RNA expression datasets of DLBCL cases with clinically annotated data. Remarkably, in concordance with our IF data, the “predicted” M+2+ 6- subgroup consistently was associated with an unfavorable prognosis in 3 independent mRNA datasets (GSE10846 n=233, GSE117556 n=469, GSE32918 n=140). In summary, we have for the first time assessed the expression of MYC, BCL2, and BCL6 at the single-cell level in DLBCL. These results may explain the apparent protective function of BCL6 expression in prior cohort studies of DEL, and provide a quantitative tool for the identification of DLBCL cases with poor survival on R-CHOP.

Citation Format: Michal Hoppe, Shuangyi Fan, Patrick Jaynes, Phuong Mai Hoang, Liu Xin, Sanjay De Mel, Li Mei Poon, Esther Chan, Joanne Lee, Yen Lin Chee, Choon Kiat Ong, Tiffany Tang, Soon Thye Lim, Nicholas Francis Grigoropoulos, Sheng-Tsung Chang, Shih-Sung Chuang, Joseph Khoury, Hyungwon Choi, Wee Joo Chng, Siok-Bian Ng, Claudio Tripodo, Anand D. Jeyasekharan. Prognostic significance of MYC, BCL2, and BCL6 colocalization at single-cell resolution in DLBCL [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-35.

Clinical Features of Plasmablastic Lymphoma: Case Series From an Asian Tertiary Cancer Center and Literature Review

Background

Plasmablastic lymphoma (PBL) is an aggressive subtype of mature B-cell non-Hodgkin lymphoma. Given its rarity, there remains a lack of clinicopathological data to guide its management, particularly on Asian patients.

Methods

We conducted a retrospective chart review of 10 patients diagnosed with PBL at the National Cancer Centre Singapore and performed a literature review of similar studies on Asian cohorts.

Results

Most patients were male (n = 9), with median age at diagnosis of 55 years (range, 33 - 91 years). Seven (70%) patients were considered to be immunocompromised. In the overall cohort, the median overall survival (OS) was 19.4 months with 5-year survival estimates given at 60% and 36% for OS and progression-free survival (PFS), respectively. At diagnosis, patients with HIV/AIDS (n = 5) were younger compared to others (median, 43 vs. 61 years; P = 0.0278), had greater number of nodal site involvement (median, 6 vs. 0; P = 0.0333), and higher international prognostic index (IPI) scores (P = 0.034 for trend). Amongst different chemotherapy used, etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (EPOCH)-based regimens (n = 6) elicited prominent complete response rates (83%) and led to durable responses even in the setting of advanced stage, high-risk IPI score and immunodeficiency.

Conclusions

In conclusion, our study describes the features of PBL in an Asian cohort and highlights disease features unique to HIV-associated PBL.

Suppressions of vibration in the Tip-Tilt mirror control system by add-on controller

Tip-Tilt mirrors play an important role in astronomical telescopes requiring the tracking performance at the level of microradian or sub-microradian. However, the closed-loop performance suffers a lot from the low-sample rate and time delay of image sensors. Especially, this issue is under the condition of vibrations, because dynamic behaviors are complex and the models are difficult to be obtained accurately. Another challenging issue comes from the measurement of vibrations and its extraction for the closed-loop control. This paper proposes a new method based on an add-on controller of the Tip-Tilt mirror to mitigate telescope vibrations. The proposed method only uses Tip-Tilt errors from an image sensor to implement a disturbance observer, which is not being restricted by an accurate model. As a result, the closed-loop performance can be optimized by designing of a proper Q-filter. To suppress the low-frequency and high-frequency vibrations, a novel Q-filter combining a lowpass filter and a bandpass filter is proposed here. The improved control method is validated by both simulation and experiment in the tip-tilt mirror control system under the condition of vibrations.

Asexual Evolution and Forest Conditions Drive Genetic Parallelism in Phytophthora ramorum

It is commonly assumed that asexual lineages are short-lived evolutionarily, yet many asexual organisms can generate genetic and phenotypic variation, providing an avenue for further evolution. Previous work on the asexual plant pathogen Phytophthora ramorum NA1 revealed considerable genetic variation in the form of Structural Variants (SVs). To better understand how SVs arise and their significance to the California NA1 population, we studied the evolutionary histories of SVs and the forest conditions associated with their emergence. Ancestral state reconstruction suggests that SVs arose by somatic mutations among multiple independent lineages, rather than by recombination. We asked if this unusual phenomenon of parallel evolution between isolated populations is transmitted to extant lineages and found that SVs persist longer in a population if their genetic background had a lower mutation load. Genetic parallelism was also found in geographically distant demes where forest conditions such as host density, solar radiation, and temperature, were similar. Parallel SVs overlap with genes involved in pathogenicity such as RXLRs and have the potential to change the course of an epidemic. By combining genomics and environmental data, we identified an unexpected pattern of repeated evolution in an asexual population and identified environmental factors potentially driving this phenomenon.