Narazaciclib, a novel multi-kinase inhibitor with potent activity against CSF1R, FLT3 and CDK6, shows strong anti-AML activity in defined preclinical models

CSF1R is a receptor tyrosine kinase responsible for the growth/survival/polarization of macrophages and overexpressed in some AML patients. We hypothesized that a novel multi-kinase inhibitor (TKi), narazaciclib (HX301/ON123300), with high potency against CSF1R (IC50 ~ 0.285 nM), would have anti-AML effects. We tested this by confirming HX301's high potency against CSF1R (IC50 ~ 0.285 nM), as well as other kinases, e.g. FLT3 (IC50 of ~ 19.77 nM) and CDK6 (0.53 nM). An in vitro proliferation assay showed that narazaciclib has a high growth inhibitory effect in cell cultures where CSF1R or mutant FLT3-ITD variants that may be proliferation drivers, including primary macrophages (IC50 of 72.5 nM) and a subset of AML lines (IC50 < 1.5 μM). In vivo pharmacology modeling of narazaciclib using five AML xenografts resulted in: inhibition of MV4-11 (FLT3-ITD) subcutaneous tumor growth and complete suppression of AM7577-PDX (FLT3-ITD/CSF1Rmed) systemic growth, likely due to the suppression of FLT3-ITD activity; complete suppression of AM8096-PDX (CSF1Rhi/wild-type FLT3) growth, likely due to the inhibition of CSF1R ("a putative driver"); and nonresponse of both AM5512-PDX and AM7407-PDX (wild-type FLT3/CSF1Rlo). Significant leukemia load reductions in bone marrow, where disease originated, were also achieved in both responders (AM7577/AM8096), implicating that HX301 might be a potentially more effective therapy than those only affecting peripheral leukemic cells. Altogether, narazaciclib can potentially be a candidate treatment for a subset of AML with CSF1Rhi and/or mutant FLT3-ITD variants, particularly second generation FLT3 inhibitor resistant variants.

A Bioengineered Nanovesicle Vaccine Boosts T-B cell Interaction for Immunotherapy of Echinococcus multilocularis

Alveolar echinococcosis (AE) is a zoonotic parasitic disease, resulting from being infected with the metacestode larvae of the tapeworm Echinococcus multilocularis (E. multilocularis). Novel prophylactic and therapeutic interventions are urgently needed since the current chemotherapy displays limited efficiency in AE treatment. Bioengineered nano cellular membrane vesicles are widely used for displaying the native conformational epitope peptides because of their unique structure and biocompatibility. In this study, four T-cells and four B-cells dominant epitope peptides of E. multilocularis with high immunogenicity were engineered into the Vero cell surface to construct a membrane vesicle nanovaccine for the treatment of AE. The results showed that the nanovesicle vaccine can efficiently activate dendritic cells, induce specific T/B cells to form a mutually activated circuit, and inhibit E. multilocularis infection. This study presents for the first time a nanovaccine strategy that can completely eliminate the burden of E. multilocularis.

Effects of ferritin heavy chain on oxidative stress, cell proliferation and apoptosis in geese follicular granulosa cells

1. The ferritin heavy chain (FHC) has a vital impact on follicular development in geese, due to its ability to regulate apoptosis of granulosa cells (GCs) and follicular atresia. However, its specific regulatory mechanisms remain unclear. The present study characterised how FHC regulates oxidative stress, cell proliferation and apoptosis in goose GCs by interfering with and overexpressing the FHC gene.2. After 72 h of interference with FHC expression, the activity of GCs decreased remarkably (p < 0.05), reactive oxygen species (ROS) levels and the expression levels of antioxidant enzyme genes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) increased significantly (p < 0.05). The overexpression of FHC for 72 h was found to significantly reduce the expression of CAT and SOD genes (p < 0.05).3. Interfering with FHC expression revealed that the expression levels of the cell proliferation gene Aurora kinase A (AURORA-A) were significantly decreased (p < 0.05), while the expression levels of the apoptosis genes B-cell lymphoma-2 (BCL-2) and cysteine aspartate-specific protease 8 (CASPASE 8) increased (p < 0.05). Further research has shown that, when interfering with FHC expression for 72 h, apoptosis rate increased by 1.19-fold (p < 0.05), but the current data showed a lower apoptosis rate after FHC overexpression by 59.41%, 63.39%, and 52.31% at three different treatment times (p < 0.05).4. In conclusion, FHC improved the antioxidant capacity of GCs, promotes GCs proliferation, and inhibits GCs apoptosis of ovarian follicles in Sichuan white geese.

Designing nanodiscs as versatile platforms for on-demand therapy

Nowadays, there has been an increasing utilization of nanomedicines for disease treatment. Nanodiscs (NDs) have emerged as a novel platform technology that garners significant attention in biomedical research and drug discovery. NDs are nanoscale phospholipid bilayer discs capable of incorporating membrane proteins and lipids within a native-like environment. They are assembled using amphiphilic biomacromolecular materials, such as apolipoprotein A1 or membrane scaffold proteins (MSPs), peptides, and styrene-maleic acid polymers (SMAs). NDs possess well-defined sizes and shapes, offering a stable, homogeneous, and biologically relevant environment for studying membrane proteins and lipids. Their unique properties have made them highly desirable for diverse applications, including cancer immunotherapy, vaccine development, antibacterial and antiviral therapy, and treating Alzheimer's disease (AD) and diabetes-related conditions. This review discusses the classifications, advantages, and applications of NDs in disease therapy.

Microplastic Distribution Characteristics and Sources on Beaches That Serve as the Largest Nesting Ground for Green Turtles in China

The threat of microplastics to marine animals and habitats is increasing, which may affect sea turtle nesting grounds. The Qilianyu Islands are the largest remaining green turtle (Chelonia mydas) nesting grounds in China. Despite being far from the mainland, microplastic pollution cannot be ignored. In this study, the level of microplastic pollution in surface sediments from three different zones, namely, the bottom, intertidal, and supratidal zone, was investigated on North Island, Qilianyu Islands. The results showed that the abundance of microplastics in the supratidal zone was significantly higher than that in the bottom zone and intertidal zone (r = 3.65, p = 0.011), with the highest average abundance of microplastics located on the southwest coast of North Island. In the bottom zone, only plastic blocks (88%) and fibers (12%) were found. The main types of microplastics in the intertidal and supratidal zones were plastic blocks (48%) and foam (42%), with polyethylene (PE) (40%) and polystyrene (PS) (34%) being the predominant components. These types and components of microplastics differed from those in the surrounding seawater, but corresponding types and components were found in the plastic debris on the beach. Meanwhile, it was also observed that there were multiple instances of fragmented plastic on the beach. Thus, we suggest that the microplastics on the beach in North Island were mainly derived from the fragmentation of microplastic debris, indicating secondary microplastics. It is recommended to further strengthen the regular cleaning of plastic debris on the beach, especially the removal of small plastic debris, in order to reduce the pollution from secondary microplastics generated by the fragmentation of beach plastic debris and to better protect China's most important sea turtle nesting site in the South China Sea.

Cellular-Membrane-Derived Vesicles for Cancer Immunotherapy

The medical community is constantly searching for new and innovative ways to treat cancer, and cellular-membrane-derived artificial vesicles are emerging as a promising avenue for cancer immunotherapy. These vesicles, which are derived from mammal and bacteria cell membranes, offer a range of benefits, including compatibility with living organisms, minimal immune response, and prolonged circulation. By modifying their surface, manipulating their genes, combining them with other substances, stimulating them externally, and even enclosing drugs within them, cellular vesicles have the potential to be a powerful tool in fighting cancer. The ability to merge drugs with diverse compositions and functionalities in a localized area is particularly exciting, as it offers a way to combine different immunotherapy treatments for maximum impact. This review contains information on the various sources of these vesicles and discusses some recent developments in cancer immunotherapy using this promising technology. While there are still obstacles to overcome, the possibilities for cellular vesicles in cancer treatment are truly exciting.

Impact of COVID-19 infection experience on mental health status of intensive care unit patients' family members: a real-world study

PURPOSE

Family members of patients hospitalized in intensive care unit (ICU) are susceptible to adverse psychological outcomes. However, there is a paucity of studies specifically examining the mental health symptoms in ICU patients' family members with a prior history of coronavirus disease 2019 (COVID-19) infection.

AIM

This study aimed to investigate mental health status and its influencing factors of ICU patients' family members with previous COVID-19 infection experience in China.

DESIGN

Nationwide, cross-sectional cohort of consecutive participants of family members of ICU patients from 10 provinces randomly selected in mainland China conducted between October 2022 and May 2023.

METHODS

The basic information scale, Self-rating depression scale, Self-rating Anxiety Scale, Impact of Event Scale-Revised, Pittsburgh sleep quality index, Perceived Stress Scale, Connor-Davidson resilience scale, Simplified Coping Style Questionnaire were employed to explore mental health status among participants.

RESULTS

A total of 463 participants, comprising 156 individuals in Covid-19 family member cohort (infection group) and 307 individuals in control family member cohort (control group), met inclusion criteria. The infection group exhibited significantly higher incidence of composite mental health symptoms compared to control group (P = 0.017). Multivariable logistic regression analysis revealed that being female, engaging in physical/mental labor, residing in rural areas, and having children were identified as risk factors for the development of depression, anxiety, and post-traumatic stress disorder symptoms, while medical history of surgery was protective factor. A predictive model demonstrated a favorable discriminative ability and excellent calibration.

CONCLUSION

COVID-19 infection experience regarded as new traumatic stressors worsen mental health status of ICU patients' family members.

Nano-sized aggregate Ti3C2-TiO2 supported on the surface of Ag2NCN as a Z-scheme catalyst with enhanced visible light photocatalytic performance

Exposing the photocatalyst's highly active facets and hybridizing the photocatalyst with suitable cocatalysts in the proper spot have been recognized as strong methods for high-performance photocatalysts. Herein, Ag2NCN/TiO2-Ti3C2 composites were synthesized by applying simple calcination and physically weak interaction deposition processes to obtain an excellent photocatalyst for Rhodamine B (Rh B) degradation when exposed to visible light. The findings from the experiments reveal that the Ag2NCN/TiO2-Ti3C2400 composite exhibited an outstanding photocatalytic rate in 80 min, with the highest Rh B degradation rate (k = 0.03889 min-1), which was 16 times higher than that of pure Ag2NCN (k = 0.00235 min-1) and 2.2 times higher than that of TiO2-Ti3C2400 (k = 0.01761 min-1). The results from the following factors: (i) the powerful interfacial contact created by the in situ formation of TiO2, and the superior electrical conductivity of Ti3C2 that makes carrier separation possible; (ii) TiO2 with electron-rich (101) facets are deposited on the surface of Ag2NCN, significantly reducing charge carrier recombination by trapping photoelectrons; (iii) a Z-type heterojunction is constructed between nanosize aggregate Ti3C2-TiO2 and Ag2NCN with non-metal Ti3C2 as the solid medium, improving the transfer and separation of photogenerated charges and inhibiting the recombination of electrons and holes. Additionally, the redox ability of the composite photocatalyst is enhanced. Furthermore, the analyses of active species showed that photogenerated superoxide radicals and holes were the principal active agents inside the photodegradation of Rh B. Moreover, the composite exhibited outstanding photo-stability.

Bioinformatics analysis to screen the key genes in pediatric Chronic Active Epstein-Barr Virus Infection

Chronic active EBV infection (CAEBV) is associated with poor prognosis and high mortality. We performed bioinformatics analysis to screen out key genes associated with CAEBV. Weighted gene co-expression network analysis (WGCNA) was used to identify the gene module which was most correlated with pediatric CAEBV. Furthermore, the differentially expressed genes (DEGs) between pediatric acute infectious mononucleosis (AIM) and pediatric CAEBV were investigated. Least absolute shrinkage and selection operator (LASSO) and random forest then were performed to identify the key variables associated with pediatric CAEBV. We also explored the correlation between these hub genes with EBV infection related pathway and immune cell abundance. Compared with pediatric AIM, 1561 DEGs were up-regulated in pediatric CAEBV, and these genes were mainly enriched in inflammatory response and inflammation-related pathways. WGCNA analysis showed that genes in blue module were mostly related to pediatric CAEBV. Genes in the blue module and DEGs are intersected to get 174 genes and these genes are also enriched in inflammatory response-related pathways. The key CAEBV-related genes were selected from these 174 genes by applying the random Forest and LASSO algorithm, resulting in TPST1, TNFSF8 and RAB3GAP1. These three genes showed good diagnostic performance in distinguishing pediatric CAEBV from pediatric AIM. Furthermore, Cibersort and GSEA analysis indicated that these three genes were positively correlated with myeloid cell enrichment and persistent EBV infection pathway, respectively. Our finding systematically analyzed the difference between AIM and CAEBV and identified TPST1, TNFSF8 and RAB3GAP1 were the key genes in the development of CAEBV.

Energetic Electron Precipitation Driven by Electromagnetic Ion Cyclotron Waves from ELFIN's Low Altitude Perspective

We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or Δ L ∼ 0.56 ) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L ∼ 5 - 7 at dusk, while a smaller subset exists at L ∼ 8 - 12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L -shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼ 1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.

Abstract 2980: HX009, a first-in-class PD1xCD47 BsAb, demonstrated anti-AML activity in PDX models

Acute myeloid leukemia (AML) is an aggressive leukemia of myeloid lineage with different subtypes (global annual mortality ~150,000). The first-line treatment is usually induction chemotherapies, followed by further chemo-/radiation therapies or stem cell transplant, etc. Immune checkpoint inhibitor (ICIs), e.g. PD1 blocker, although a great success for treating many solid tumors, has yet to show convincing activity in AML. CD47, a “don’t eat me” receptor frequently found on the surface of tumor cells, including hematological malignances such as AML, prevents phagocytosis by interacting to its ligand, SIRPα, on the surface of macrophages. CD47 is also now shown as a key immune checkpoint for both innate and adoptive immunity (Liu et al., 2018). CD47 targeting, actively being tested for MSD and AML in clinics, encounters challenges for the reported toxicities (e.g. anemia/thrombocytopenia) as well as inadequate efficacy (Feng et al., 2019). Majority of investigational CD47 targeting agents in the clinics are combination therapies with other modality in order to increase the likelihood of success. To this end, it is prudent to develop agents with dual targeting agents, particularly for both the innate and adoptive immune checkpoints. We describe a novel specially designed/constructed bi-specific antibody (BsAb), HX009, targeting CD47 and PD1 for the treatment of cancers. We tested HX009 in several preclinical AML-PDXs (patient-derived xenograft models) via systemic engraftment: AM8096 (CD47lo, H-score of 55 by IHC), AM7577 (CD47hi, H-score of 237)(An et al., 2017) and AM5512 (CD47hi, H-score of 198). All three PDXs responded to 10mg/kg twice weekly dose of HX009 (IP) as measured either by leukemic burden in peripheral blood at different timepoints, and in both spleen and bone marrow at the termination, or by survival. Since there is no T-cell function in xenograft models, all anti-leukemic activities observed should be attributed to the CD47 blockade, not PD1 blockade. AM7577 model responded significantly better than AM8096, likely due to the significantly higher expression of CD47 and also better than Ara-C standard of care (SOC) treatment at 3mg/kg. In contrast, AM8096 responded even less to HX009 than Ara-C. In contrast, in the subcutaneous transplanted AML cell line-derived model, MV4-11, there is little anti-tumor activity observed, although there is significant expression of CD47 on the tumor cells. In conclusion, our data seems to suggest that HX009 could be a candidate immunotherapy for CD47hi AML, with CD47 expression being a positive predictive biomarker, warranting further evaluation.

Citation Format: Xiaoyu An, Jinping Liu, Hang Ke, Lingxin Xiong, Xiaolong Tu, Lei Zhang, Faming Zhang, Henry Li. HX009, a first-in-class PD1xCD47 BsAb, demonstrated anti-AML activity in PDX models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2980.

HX009, a novel BsAb dual targeting PD1 x CD47, demonstrates potent anti-lymphoma activity in preclinical models

Both PD1/PD-L1 and CD47 blockades have demonstrated limited activity in most subtypes of NHL save NK/T-cell lymphoma. The hemotoxicity with anti-CD47 agents in the clinic has been speculated to account for their limitations. Herein we describe a first-in-class and rationally designed bispecific antibody (BsAb), HX009, targeting PD1 and CD47 but with weakened CD47 binding, which selectively hones the BsAb for tumor microenvironment through PD1 interaction, potentially reducing toxicity. In vitro characterization confirmed: (1) Both receptor binding/ligand blockade, with lowered CD47 affinity; (2) functional PD1/CD47 blockades by reporter assays; (3) T-cell activation in Staphylococcal-enterotoxin-B-pretreated PBMC and mixed-lymphocyte-reaction. In vivo modeling demonstrated antitumor activity in Raji-B and Karpass-229-T xenograft lymphomas. In the humanized mouse syngeneic A20 B-lymphoma (huCD47-A20) HuGEMM model, which has quadruple knocked-in hPD1xhPD-L1xhCD47xhSIRPα genes and an intact autologous immune-system, a contribution of effect is demonstrated for each targeted biologic (HX008 targeting PD1 and SIRPα-Fc targeting CD47), which is clearly augmented by the dual targeting with HX009. Lastly, the expression of the immune-checkpoints PD-L1/L2 and CD47 seemed co-regulated among a panel of lymphoma-derived-xenografts, where HX009 maybe more effective in those with upregulated CD47. Our data warrants HX009's further clinical development for treating NHLs.

Prior differences in previous trauma exposure primarily drive the observed racial/ethnic differences in posttrauma depression and anxiety following a recent trauma

BACKGROUND

Racial and ethnic groups in the USA differ in the prevalence of posttraumatic stress disorder (PTSD). Recent research however has not observed consistent racial/ethnic differences in posttraumatic stress in the early aftermath of trauma, suggesting that such differences in chronic PTSD rates may be related to differences in recovery over time.

METHODS

As part of the multisite, longitudinal AURORA study, we investigated racial/ethnic differences in PTSD and related outcomes within 3 months after trauma. Participants (n = 930) were recruited from emergency departments across the USA and provided periodic (2 weeks, 8 weeks, and 3 months after trauma) self-report assessments of PTSD, depression, dissociation, anxiety, and resilience. Linear models were completed to investigate racial/ethnic differences in posttraumatic dysfunction with subsequent follow-up models assessing potential effects of prior life stressors.

RESULTS

Racial/ethnic groups did not differ in symptoms over time; however, Black participants showed reduced posttraumatic depression and anxiety symptoms overall compared to Hispanic participants and White participants. Racial/ethnic differences were not attenuated after accounting for differences in sociodemographic factors. However, racial/ethnic differences in depression and anxiety were no longer significant after accounting for greater prior trauma exposure and childhood emotional abuse in White participants.

CONCLUSIONS

The present findings suggest prior differences in previous trauma exposure partially mediate the observed racial/ethnic differences in posttraumatic depression and anxiety symptoms following a recent trauma. Our findings further demonstrate that racial/ethnic groups show similar rates of symptom recovery over time. Future work utilizing longer time-scale data is needed to elucidate potential racial/ethnic differences in long-term symptom trajectories.

The feasibility of a novel computer-aided classification system for the characterisation and diagnosis of breast masses on ultrasound: a single-centre preliminary test study

AIM

To introduce a novel computer-aided classification (CAC) system and investigate the feasibility of characterising and diagnosing breast masses on ultrasound (US).

MATERIALS AND METHODS

A total of 246 breast masses were included. US features and the final assessment categories of the breast masses were analysed by a radiologist and the CAC system according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon. The CAC system evaluated the BI-RADS assessment from the fusion of multi-view and colour Doppler US images without (SmartBreast) or with combining clinical variables (m-CAC system). The diagnostic performance and agreement of US characteristics between the radiologist and the CAC system were compared.

RESULTS

The agreement between the radiologist and the CAC system was substantial for mass shape (κ = 0.673), orientation (κ = 0.682), margin (κ = 0.622), posterior features (κ = 0.629), calcifications in a mass (κ = 0.709) and vascularity (κ = 0.745), fair for echo pattern (κ = 0.379), and moderate for BI-RADS assessment (κ = 0.575). With BI-RADS 4a as the cut-off value, the specificity (52.5% versus 25%, p<0.0001) and accuracy (73.98% versus 62.6%, p=0.0002) of the m-CAC system were improved without significant loss of sensitivity (94.44% versus 98.41%, p=0.1250) compared with the SmartBreast. The m-CAC system showed similar specificity (52.5% versus 45.83%, p=0.2430) and accuracy (73.98% versus 73.58%, p=1.0000) as the radiologist, but a lower sensitivity (94.44% versus 100%, p=0.0156).

CONCLUSION

The CAC system showed an acceptable agreement with the radiologist for characterisation of breast lesions. It has the potential to mimic the decision-making behaviour of radiologists for the classification of breast lesions.

A living biobank of matched pairs of patient-derived xenografts and organoids for cancer pharmacology

Patient-derived tumor xenograft (PDX)/organoid (PDO), driven by cancer stem cells (CSC), are considered the most predictive models for translational oncology. Large PDX collections reflective of patient populations have been created and used extensively to test various investigational therapies, including population-trials as surrogate subjects in vivo. PDOs are recognized as in vitro surrogates for patients amenable for high-throughput screening (HTS). We have built a biobank of carcinoma PDX-derived organoids (PDXOs) by converting an existing PDX library and confirmed high degree of similarities between PDXOs and parental PDXs in genomics, histopathology and pharmacology, suggesting "biological equivalence or interchangeability" between the two. Here we demonstrate the applications of PDXO biobank for HTS "matrix" screening for both lead compounds and indications, immune cell co-cultures for immune-therapies and engineering enables in vitro/in vivo imaging. This large biobank of >550 matched pairs of PDXs/PDXOs across different cancers could become powerful tools for the future cancer drug discovery.

[Efficacy and safety of neoadjuvant toripalimab combined with nimotuzumab and chemotherapy in patients with unresectable stage Ⅳ squamous cell carcinoma of penis]

Objective: To compare the efficacy and safety of neoadjuvant chemotherapy alone or combined with toripalimab and nimotuzumab in patients with unresectable locally advanced or metastatic squamous cell carcinoma of penis. Methods: A total of 33 patients with unresectable squamous cell carcinoma of penis undergoing neoadjuvant chemotherapy alone or combined with toripalimab and nimotuzumab at Sun Yat-sen University Cancer Center from May 2015 to June 2021 were enrolled retrospectively. All the patients were male, with a median age (M(IQR))of 49.0 (13.5) years (range: 30 to 70 years). According to the therapy protocols, patients were divided into the chemotherapy group (16 cases) and the triple combination group (17 cases). Log-rank test was used to compare the progression-free survival and overall survival. χ² test or Fisher exact method was used to compare the objective response rate, pathological down-stage rate and adverse events between these two groups. Results: The follow-up time was 28.1(19.2) months (range: 1.5 to 33.4 months). Patients of triple combination group were observed significantly longer progression-free survival (30.0 months vs. 8.2 months, χ²=3.998, P=0.046) than those of chemotherapy group. The median overall survival of the triple combination group and chemotherapy group were not reached and 15.2 months (χ²=3.298, P=0.069), respectively. Although there was no significant difference in the subsequent surgical resection rate between these two groups (12/17 vs.11/16, P=1), the objective response rate and the pathological complete response rate in triple combination group were significantly higher than in chemotherapy group (13/17 vs. 6/16, χ²=5.125, P=0.024; 6/7 vs. 0, P=0.001). The main common grade 1 to 2 adverse events in the triple combination group were alopecia (16 cases), anemia (15 cases), and nausea (14 cases). The main common grade 1 to 2 adverse events in the chemotherapy group were anemia (14 cases), alopecia (12 cases), decreased appetite (12 cases), and nausea (11 cases). The incidence of adverse events ≥grade 3 was similar in the triple combination group and chemotherapy group (8/17 vs. 6/16, χ²=0.308, P=0.579). There was no grade 3 adverse event in both groups. Conclusion: Compared with traditional chemotherapy alone, chemotherapy combined with toripalimab and nimotuzumab provides longer progression-free survival and similar toxicity for unresectable stage Ⅳ squamous cell carcinoma of penis.

Structural characterization, acute toxicity assessment and protective effects of selenylated apple pectin on dextran sulfate sodium-induced ulcerative colitis

This study was aimed at investigating the structural characterization, acute toxicity and protective effect of selenylated apple pectin on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. Selenylated apple pectin was characterized by ion chromatography, NMR and SEC-RI-MALLS. The acute toxicity and protective effect of selenylated apple pectin against UC were investigated by gavage administration in mice. The organ state and coefficients, inflammatory cytokine (IL-6, IL-10 and TNF-α) contents in serum, GSH-Px activity and MPO content in colon tissues were also evaluated. The results indicated that selenylated apple pectin was non-toxic and contained 244.28 μg_selenium per g. The monosaccharide composition with different molar ratios, different relative molecular weights and a weakened signal peak (CH₂-O group) at 3-4 ppm were observed after selenylation. The selenylated apple pectin showed the protective effect against UC by down-regulating IL-6 and TNF-α contents and up-regulating the IL-10 content in serum, as well as increasing the GSH-Px activity and decreasing the MPO content in colon tissues. Moreover, DSS-induced alterations were effectively recovered by a high-dose sample. These findings provide evidence in support of selenylated apple pectin as a novel dietary selenium supplement for UC protection.

Design of a Single-Channel Chaotic Secure Communication System Implemented by DNA Strand Displacement

DNA strand displacement (DSD) is regarded as a foundation for the construction of biological computing systems because of the predictability of DNA molecular behaviors. Some complex system dynamics can be approximated by cascading DSD reaction modules with different functions. In this paper, four DSD reaction modules are used to realize chaotic secure communication based on drive-response synchronization of four-dimensional chaotic systems. The system adopts the communication technology of chaos masking and uses a single-channel synchronization scheme to achieve high accuracy. The simulation results demonstrate that encryption and decryption of the signal are achieved by the design. Moreover, the system is robust to noise signals and interference during the DNA reactions. This work provides a method for the application of DNA molecular computation in the communication field.

Economic burden of public health care and hospitalisation associated with COVID-19 in China

OBJECTIVES

This study aimed to evaluate the socio-economic burden imposed on the Chinese healthcare system during the coronavirus disease 2019 (COVID-19) pandemic.

STUDY DESIGN

A cross-sectional study was used to investigate how COVID-19 impacted health and medical costs in China. Data were derived from a subdivision of the Centers for Disease control and Prevention of China.

METHODS

We prospectively collected information from the Centers for Disease Control and Prevention and the designated hospitals to determine the cost of public health care and hospitalisation due to COVID-19. We estimated the resource use and direct medical costs associated with public health.

RESULTS

The average costs, per case, for specimen collection and nucleic acid testing (NAT [specifically, polymerase chain reaction {PCR}]) in low-risk populations were $29.49 and $53.44, respectively; however, the average cost of NAT in high-risk populations was $297.94 per capita. The average costs per 1000 population for epidemiological surveys, disinfectant, health education and centralised isolation were $49.54, $247.01, $90.22 and $543.72, respectively. A single hospitalisation for COVID-19 in China cost a median of $2158.06 ($1961.13-$2325.65) in direct medical costs incurred only during hospitalisation, whereas the total costs associated with hospitalisation of patients with COVID-19 were estimated to have reached nearly $373.20 million in China as of 20, May, 2020. The cost of public health care associated with COVID-19 as of 20, May, 2020 ($6.83 billion) was 18.31 times that of hospitalisation.

CONCLUSIONS

This study highlights the magnitude of resources needed to treat patients with COVID-19 and control the COVID-19 pandemic. Public health measures implemented by the Chinese government have been valuable in reducing the infection rate and may be cost-effective ways to control emerging infectious diseases.

Abstract P103: The introduction of a single strain of Bacillus into a germ-free environment did not impact the anti-PD-1 efficacy in a MC38 syngeneic model

Background. Although immunotherapy has led to exceptional and durable clinical response, the majority of patients respond poorly to the current immunotherapies. Growing evidence has linked some of the poor responsiveness to the gut microbiota, and the modulation of gut microbiome composition is becoming a promising new strategy to enhance immune checkpoint inhibitor (ICI) treatment outcome. Mouse tumor modelling under germ-free (GF) conditions combined with introduction of defined bacterial strains could be a useful approach to investigate the impact of microbiota on ICI efficacy, as well as understanding the underlying mechanisms. We previously demonstrated that GF mice exhibited a significantly poor response to anti-PD-1 therapy when compared to the specific pathogen free (SPF) mice in a subcutaneous MC38 colorectal cancer model, which is consistent with other reports. Methods. Introduction of a single strain of Bacillus in the GF-environment was assessed for its impact on the anti-mouse PD-1 monoclonal antibody (mAb) therapy in GF-mice and SPF mice, both for efficacy and pharmacodynamics tumor infiltrating lymphocytes (TILs) profiling. C57BL/6 mice were inoculated subcutaneously with MC38 tumor cells and when the tumors were reached 80-120mm3, the mice were randomized for isotype or anti-PD-1 mAb treatment. Fecal sample 16S rRNA analysis (NGS) was used to confirm the gut bacteria status. Results. The MC38 tumor in GF mice has significantly fast baseline growth kinetics, even with the introduction of Bacillus under GF conditions compared to SPF mice, suggesting tumor immunity was not enhanced by Bacillus. Despite the introduction of Bacillus, GF mice also showed reduced response to anti-PD-1 treatment when compared to the SPF mice as previously reported, further confirming that introduction of Bacillus had minimal effects on the efficacy of anti-PD-1 therapy. Moreover, the SPF mice and GF mice with Bacillus exhibited distinct profiles of TILs, consistent with distinct efficacies as observed. GF free mice showed a lower frequency of CD45+ TILs in comparison to SPF mice. In addition, GF mice exhibited lower frequency of CD8+ TILs and TIL- NKT when compared to the SPF mice, both of which are consistent with the stronger efficacy seen in SPF mice. Meanwhile, GF mice also exhibited higher granulocytic myeloid derived suppressor cells (gMDSC) and lower M1/M2 ratio, both of which imply a more suppressive tumor microenvironment in GF mice. Fecal sample analysis using 16S rRNA analysis confirmed a single strain of Bacillus was indeed introduced into the guts of all the GF mice. Conclusions. The GF conditions provide a useful environment for the investigation of specific microbiota strains on the impact on ICI treatment outcome. In summary, the introduction of Bacillus in GF mice did not impact the efficacy of anti-PD-1, thus suggesting that other strain(s) of gut microbiota in SPF mice may impact this and need to be investigated.

Citation Format: Tao Yang, Bonnie Xiaobo Chen, Rongfei Lu, Xiaoyu An, Mingfa Zang, Jingjun Li, Sheng Guo, Wubin Qian, Jian Fei, Tongyang Hao, Edward Xu, Henry Li. The introduction of a single strain of Bacillus into a germ-free environment did not impact the anti-PD-1 efficacy in a MC38 syngeneic model [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P103.

724 Evaluation of an anti-human IL-1β antibody in monosodium urate crystals-induced peritonitis model in hIL-1β HuGEMM™ mice

Background

Gout is a chronic inflammatory disease featuring the deposition of monosodium urate (MSU) crystals in the synovial fluid of patients, followed by NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome activation and bioactive IL-1β release, which recruits neutrophils to the local inflammation sites. Blocking IL-1β function is becoming a a potent therapeutic approach for gout and gouty arthritis. Conventional MSU-induced peritonitis in C57BL/6 mice provides a simple and rapid evaluation of therapeutics targeting inflammasome activation. However, this murine model has limitations when it comes to the evaluation of human-specific antibodies, for example, anti-human IL-1β (anti-hIL-1β) monoclonal antibodies (mAb). Thus, a murine model to assess the efficacy of anti-hIL-1β mAb is needed. We have developed a hIL-1β knock-in mouse model (hIL-1β HuGEMM™), which is able to facilitate the pre-clinical evaluation of drugs targeting specific human biological molecules especially when mouse ortholog is not available. Therefore, an MSU crystals induced peritonitis model using hIL-1β HuGEMM™ mice provides a robust model to evaluate therapies targeting hIL-1β.

Methods

MSU crystals were injected intraperitoneally into human IL-1β (hIL-1β) knock-in mice, where the coding sequence of mouse IL-1β was replaced by hIL-1β. Prior to MSU crystal administration, mice received treatment of either vehicle or anti-hIL-1β antibody. Six hours facilitate post MSU crystal injection, serum and lavage flushed with PBS were collected. Subsequently, cytokine protein levels in the serum were determined by MSD, and the population of polymorphonuclear leukocytes (PMNs) (live CD11b+ Ly-6GHi cells) in the lavage was analysed by flow cytometry.

Results

The vehicle treatment group showed a dramatic increase in hIL-1β secretion and PMN leukocytes, in comparison to the group that did not receive MSU, which suggests a successful induction of acute inflammatory response in the peritoneal cavity. In contrast, mice that received a single administration of anti-hIL-1β antibody 24 hours prior to MSU injection exhibited a significantly lower level of hIL-1β when compared to the vehicle treatment group, which implies that the anti-hIL-1β mAb efficaciously neutralized hIL-1β secretion. In addition, TNF-α and IL-6, two further cytokines downstream of IL-1β, were significantly reduced in the anti-hIL-1β mAb treatment group. However, the PMN leukocyte infiltration in the anti-hIL-1β mAb treatment group did not change in comparison to the vehicle group.

Conclusions

In this study, an MSU crystals-induced peritonitis model was successfully established in hIL-1β HuGEMM mice, which has the potential to evaluate immune therapeutics with anti-hIL-1β blockades.

Isolation of Thalassobius mangrovi sp. nov., a novel bacterium in the family Rhodobacteraceae, from marine mangrove sediment

A Gram-stain-negative, strictly aerobic and oval-shaped bacterial strain with a flagellum, designated GS-10^T, was isolated from mangrove wetland sediment. GS-10^T grew at 20-40 °C (optimum, 37 °C), in the pH range of 5.0-11.0 (optimum, 6.0-8.0) and under various NaCl concentrations from 1 to 11 % (w/v) (optimum, 5-6 %). The respiratory quinone was ubiquinone-10, and the predominant polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The major fatty acids (>10 % of the total fatty acids) were summed feature 4 (C_17 : 1iso I/anteiso B) and summed feature 8 (C_18 : 1ω7c and/or C_18 : 1ω6c). The G+C content of the genomic DNA was 63.71 %. On the basis of the results from comparative analysis of the 16S rRNA gene sequence, GS-10^T represents a member of the family Rhodobacteraceae and had the highest sequence similarity to Thalassobius gelatinovorus CECT 4357^T (97.47 %), followed by Lutimaribacter pacificus W11-2B^T (97.03 %), Marivita cryptomonadis CL-SK44^T (96.83 %), Thalassobius autumnalis CECT 5118^T (96.75 %) and Thalassobius mediterraneus CECT 5383^T (96.68 %). Phylogenetic trees based on 16S rRNA gene sequences, multilocus sequence analysis (MLSA) and whole genome sequences revealed that GS-10^T clustered with species within the genus Thalassobius. The average nucleotide identity (ANI) and the average amino acid identity (AAI) values were calculated from complete genome sequences and indicated that GS-10^T represented a novel species of the genus Thalassobius, and the name Thalassobius mangrovi sp. nov. is proposed for this species. The type strain of Thalassobius mangrovi is GS-10^T (=MCCC 1K03624^T=KCTC 82131^T).

Pain after a motor vehicle crash: The role of socio-demographics, crash characteristics and peri-traumatic stress symptoms

BACKGROUND

The vast majority of individuals who come to the emergency department (ED) for care after a motor vehicle collision (MVC) are diagnosed with musculoskeletal strain only and are discharged to home. A significant subset of this population will still develop persistent pain and posttraumatic psychological sequelae may play an important role in pain persistence.

METHODS

We conducted a multisite longitudinal cohort study of adverse post-traumatic neuropsychiatric sequelae among patients seeking ED treatment in the aftermath of a traumatic life experience. We report on a sub-group of patients (n = 666) presenting after an MVC, the most common type of trauma and we examine associations of socio-demographic and MVC characteristics, and persistent pain 8 weeks after MVC. We also examine the degree to which these associations are related to peritraumatic psychological symptoms and 2-week acute stress reactions using an applied approach.

RESULTS

Eight-week prevalence of persistent moderate or severe pain was high (67.4%) and positively associated with patient sex (female), older age, low socioeconomic status (education and income) and pain severity in the ED. Peritraumatic stress symptoms (distress and dissociation) appear to exert some influence on both acute pain and the transition from acute to persistent pain.

DISCUSSION AND CONCLUSIONS

The early aftermath of an MVC may be an important time period for intervening to prevent and reduce persistent pain. Substantial variation in mediating pathways across predictors also suggests potential diverse and complex underlying biological and psychological pathogenic processes are at work in the early weeks following trauma.

SIGNIFICANCE

The first several days after trauma may dictate recovery trajectories. Persistent pain, pain lasting beyond the expected time of recovery, is associated with pain early in the recovery period, but also mediated through other pathways. Future work is needed to understand the complex neurobiological processes in involved in the development of persistent and acute post-traumatic pain.

Vertically stacked RGB LEDs with optimized distributed Bragg reflectors

The design and fabrication of a vertically stacked red-green-blue (RGB) light-emitting diode (LED) with novel, to the best of our knowledge, wavelength-selective distributed Bragg reflectors (DBRs) are demonstrated. The two DBRs are optimized to achieve selective reflectance in the RGB spectral region through theoretical calculations and simulation modeling. The insertion of optimal DBRs into the stack structure can effectively reflect downward emission from the upper chip without filtering the emission from the lower chips, thereby increasing the luminous efficiency for white emission with a color temperature range of 3000-8000 K by 1.6-7.4%. The optical performances of stacked devices with and without DBRs are thoroughly studied, verifying the effectiveness of the proposed wavelength-selective DBR structure.

[Cost-effectiveness of primary prophylaxis with PEG-rhG-CSF in early-stage breast cancer patients receiving chemotherapy in China]

Objective: To evaluate the cost effectiveness of primary prophylaxis (PP) with pegylated recombinant human granulocyte colony stimulating factor (PEG-rhG-CSF), PP with recombinant human granulocyte colony stimulating factor (rhG-CSF) and no prophylaxis in women with early-stage breast cancer in China. Methods: Two phase Markov models were constructed for a hypothetical cohort of patients aged 45 with stage Ⅱ breast cancer. The first phase modelled costs and outcomes of 4 cycles docetaxel combined with cyclophosphamide [TC×4, febrile neutropenia (FN) risk>20%] chemotherapy, which assumptions based on literature reviews, including FN rates [base-case (deterministic sensitivity analysis range), 0.29 (0.24-0.35)] and related events [FN case-fatality, 3.4 (2.7-4.1)]. Second phase modelled the long term survival which was link with the relative dose intensity (RDI) [mortality hazard ratio (HR) of RDI < 85% vs ≥85%, 1.45 (1.00-2.32)]. Clinical effectiveness, therapeutic costs, and economic utilities were estimated from peer-reviewed publications and expert opinions in case of unavailability of published evidences. Results: Compared to rhG-CSF PP and no prophylaxis, the cost of PEG-rhG-CSF PP increased to 5 208.19 RMB and 5 222.73 RMB, respectively. The quality-adjusted life-years (QALYs) enhanced to 0.066 and 0.297, respectively. Accordingly, the incremental cost effectiveness ratios (ICERs) are 79 146.3 RMB and 17 558.77 RMB per QALY, which were both below the willingness to pay (WTP) threshold of three times GDP per capita (18, 000 RMB) recommended by the WHO. Sensitivity analysis suggested that the more clinically effective the primary prophylaxis with PEG-rhG-CSF is, the more cost-effective primary prophylaxis with PEG-rhG-CSF will be. And the lower the mortality HR of RDI<85% vs ≥85% is, the more cost-effective primary prophylaxis with PEG-rhG-CSF will be. Conclusion: Although the cost of PP PEG-rhG-CSF is higher, considering the additional benefits, the administrating of PP PEG-rhG-CSF is likely to be a cost-effective alternative to PP rhG-CSF and no prophylaxis in patients with early stage breast cancer whose FN risks are more than 20% in China.

Abstract 2798: Cancer stem cells profiling of the colorectal cancer patient-derived xenograft model and corresponding in vitro organoid model by multiplex IHC

Background. Organoids are derived from stem cells from patient tissue, with self-capability as well as self-organization [1] and have been reported to mimic the structural and functional features of their in vivo counterpart[2]. Patient-derived xenografts (PDXs) are considered predictive in vivo cancer model for preclinical research and we have built and characterized a large library of PDX biobank. We recently have also established a large biobank of PDX-derived organoids (PDXOs) from our PDX biobank (&gt;200) using the Hubrecht Organoid Technology (HUB), with evidence of “biological equivalence” to their parental PDXs, sharing similar profiles of genomics and pathology, as well as pharmacology. PDX and the derived PDXO thus constitute matched in vivo and in vitro model pairs, with great potential pharmaceutical applications. This report attempted to verify and characterize the CSC components of both models by multiplex IHC.

Method. Five CRC PDX/PDXO pairs (CR1250, CR2258, CR3310,CR5048, CR11372) were subjected to histopathology (HE staining) and CSCs (Multiplex IHC staining) analysis. TSA-based multiplex IHC staining in Leica Bond Rx automatic platform was performed using a 4-plex CSC panel: DAPI (Sigma, #9542), CD133 (Cell Signaling, #86781), CD44 (abcam, ab51037), SOX2 (Cell Signaling, #14962) and basal cell marker pan-CK (Cell Signaling, #4545), followed by whole slide scan using Vectra® Polaris™ automated quantitative pathology imaging system (PerkinElmer) and quantified by HALO image analysis (Indica labs).

Results. H&E staining of the five CRC-PDXOs showed typical adenocarcinoma histology structure, e.g. recognizable adenocarcinoma cells in tubular or vesicular glands, similar to those of the matched PDXs. The presence of the basal cells marker (pan-CK) was observed predominantly on the cell surface with broader pattern in corresponding matched models. Similarly, CD44, a known dominant marker for CRC CSC was observed broadly on the surface of tumor cells in both models. Moreover, pan-CK and CD44 showed universal co-localization, thus suggesting that pan-CK+CD44+ cells become the primary cellular composition of CRC PDXOs and PDXs. Interestingly, CD133, another marker of CSC, displayed distinct staining patterns between PDXOs and PDXs: predominantly outside of tumor glandular in PDXs (periglandular-like) vs. intraglandular in PDXOs (intraglandular-like). SOX2, a key transcription factor for CSCs and vital to CSC development, was also broadly present in all PDXOs and PDXs with similar pattern.

Conclusion. Multiplex IHC could be a powerful tool to investigate CSC component in tumors and tumor models. Our preliminary data seem to show that most cells, in both PDX and PDXO models, resemble basal cell layer where pan-CK+/CD44+ CSCs also co-localized, consistent with hypothesis of both being CSC-driven disease models.

References

1.

Tuveson D, et al. Cancer modeling meets human organoid technology. Science. 2019 Jun 7;364(6444):952-955.

2.

Vlachogiannis G, et al. Patient-derived organoids model treatment response of metastatic gastrointestinal cancers. Science. 2018 Feb 23;359(6378):920-926.

3.

Dany N, et al. Cancer Stem Cells: Basic Concepts and Therapeutic Implications. Annu Rev Pathol. 2016 May 23;11:47-76.

Citation Format: Xiaolong Tu, Xiaoyu An, Xiaoxi Xu, Xinhe Feng, Chen Jiang, Jared Allan Gunn, Henry Li. Cancer stem cells profiling of the colorectal cancer patient-derived xenograft model and corresponding in vitro organoid model by multiplex IHC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2798.

Correlation between the hemoporfin-mediated photodynamic treatment response and the dermoscopy vascular pattern in patients with a port-wine stain: a prospective study

BACKGROUND

Vascular targeted photodynamic therapy (PDT) is a novel and promising therapy for the treatment of port-wine stains (PWS). There has been little prior exploration to our knowledge of how the dermatological vascular pattern may predict the response to PDT.

OBJECTIVES

To analyse whether the vascular pattern classifications of PWS by dermoscopy can predict the efficacy of PDT.

METHODS

This prospective cohort study included 163 patients with a clinical diagnosis of PWS who were treated twice with hemoporfin-mediated photodynamic therapy (HMME-PDT) at two-month intervals and followed up for 6 months. The vascular manifestations of dermoscopy with PWS were independently classified into 8 categories by 3 dermatologists. Images of the lesions were taken using VISIA, and the vascular patterns were imaged by dermoscopy by the same investigator. Images were captured before and after each treatment. The efficacy was evaluated with pre- and post-treatment VISIA images, and correlations between efficacy and vascular patterns were analysed by four dermatologists in a blinded and independent manner, between 10 January 2019 and 11 December 2019.

RESULTS

In the dermoscopy images for the whole cohort, dotted and globular vessels (15.3%), short clubbed vessels (18.4%) and curved vessels (12.9%) were highly associated with cure and beneficial treatment effects. Pale halos surrounding brown dots (8.0%) and arborizing vessels (9.8%) were mainly correlated with skin lesion alleviation. Mixed vessels (12.9%), a grey-whitish veil (11.7%) and reticular patterns (11.0%) were mainly associated with no effect. The differences between each subgroup were statistically significant (P = 0.000).

CONCLUSIONS

There is a clear correlation between the efficacy of PDT and the dermoscopy pattern in patients with PWS. Dermoscopy may therefore provide very useful clinical information prior to treatment in these cases. In addition, the vascular manifestations of PWS determined by dermoscopy help to predict response to PDT and manage patient expectations.

[Meta-analysis of the influence of prophylactic central lymph node dissection on the prognosis of patients with thyroid micropapillary carcinoma]

Objective: To evaluate the efficacy and safety of prophylactic central neck dissection (pCND) in papillary thyroid microcarcinoma (PTMC). Method: The PubMed, EMbase, Web of Knowledge, CBM, Wanfang, and CNKI databases were searched, and controlled trials and cohort studies of central lymph node dissection for cervical cancer in PTMC surgery were collected. The search time was from the establishment of the library to September 2018. Meta-analysis was performed on 4 articles that met the inclusion criteria to calculate the relative risk. Result: A total of 1 169 cases were included in 4 retrospective cohort studies. In addition to conventional thyroidectomy, pCND reduced the risk of local recurrence and did not increase the recurrent laryngeal nerve (RLN) injury (temporary or permanent), the incidence of permanent hypocalcemia. Postoperative temporary hypocalcemia is more common after surgery with pCND.Conclusion: Prophylactic central lymph node dissection reduces local recurrence rates without increasing long-term complications compared with thyroid and tumor resection alone.

Abstract 1097: Establishment of murine immune and stroma reference bench for TME study on in vivo models

Cancer is a heterogeneous disease and highly related to immunological system. Experimental animal models such as patient derived xenograft (PDX) are excellent system to understand tumor microenvironment (TME), especially for immunotherapy. Deconvolution analysis on bulk tissue genomics of these in vivo tumor models is one of cost-effective ways to investigate TME. Several groups have released robust deconvolution algorithms with human immune cell signature. Our previous research on ~1600 transcriptomes of PDX collection identified various human immune and stromal contents in 24 different cancer types. However, no appropriate mouse immune signature generated from single standard platform could be used so far to study murine immune and stromal contents. To this end, we established a reference dataset by performing transcriptome sequencing of over 10 types of mouse immune and stromal cells, including different subtypes of B cells, T cells, monocytes, macrophages, dendritic cells, neutrophils, natural killer cells, cancer associated fibroblasts, glial cell and epithelial cell, etc. These cells were isolated from 3 different tissues (bone marrow, lymph node and spleen) on tumor-bearing and non-tumor-bearing mice covering a variety of mouse strains. We identified the transcriptomic landscape of murine immune system as well as difference across source tissues/organs and mouse strains. Based on this reference set, which is generated from single standard protocol, we defined precision gene signatures for studied cells and refined deconvolution algorithms for mouse TME studies. We further evaluated multiple algorithms by flow cytometry. In conclusion, our murine immune and stroma reference dataset will be essential basis for model selection in immunotherapy study in future.

Note: This abstract was not presented at the meeting.

Citation Format: Jia Xue, Xiaoyu An, Xiaobo Chen, Wubin Qian, Henry Q. Li, Sheng Guo. Establishment of murine immune and stroma reference bench for TME study on in vivo models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1097.

Immunophenotyping of Orthotopic Homograft (Syngeneic) of Murine Primary KPC Pancreatic Ductal Adenocarcinoma by Flow Cytometry

Homograft (syngeneic) tumors are the workhorse of today's immuno-oncology (I/O) preclinical research. The tumor microenvironment (TME), particularly its immune-components, is vital to the prognosis and prediction of treatment outcomes, especially those of immunotherapy. TME immune-components are composed of different subsets of tumor-infiltrating immune cells assessable by multi-color FACS. Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest malignances lacking good treatment options, thus an urgent and unmet medical need. One important reason for its non-responsiveness to various therapies (chemo-, targeted, I/O) has been its abundant TME, consisting of fibroblasts and leukocytes that protect tumor cells from these therapies. Orthotopically implanted PDAC is believed to more accurately recapture the TME of human pancreatic cancers than conventional subcutaneous (SC) models. Homograft tumors (KPC) are transplants of mouse spontaneous PDAC originating from genetically engineered KPC-mice (Kras^G12D/+/P53^-/-/Pdx1-Cre) (KPC-GEMM). The primary tumor tissue is cut into small fragments (~2 mm³) and transplanted subcutaneously (SC) to the syngeneic recipients (C57BL/6, 7-9 weeks old). The homografts were then surgically orthotopically transplanted onto the pancreas of new C57BL/6 mice, along with SC-implantation, which reached tumor volumes of 300-1,000 mm³ by 17 days. Only tumors of 400-600 mm³ were harvested per approved autopsy procedure and cleaned to remove the adjacent non-tumor tissues. They were dissociated per protocol using a tissue dissociator into single-cell suspensions, followed by staining with designated panels of fluorescently-labeled antibodies for various markers of different immune cells (lymphoid, myeloid and NK, DCs). The stained samples were analyzed using multi-color FACS to determine numbers of immune cells of different lineages, as well as their relative percentage within tumors. The immune profiles of orthotopic tumors were then compared to those of SC tumors. The preliminary data demonstrated significantly elevated infiltrating TILs/TAMs in tumors over the pancreas, and higher B-cell infiltration into orthotopic rather than SC tumors.

Abstract B28: Validation and characterization of MiXeno humanized mouse models for immuno-oncology

Despite the unprecedented success of immune checkpoint blockade therapy in patients with various cancer types, a lack of effective preclinical mouse models remains a major challenge for the development of novel immunotherapeutics. Different strategies to humanize immunodeficient mouse model systems have been reported, including replenishment with human hematopoietic stem cells (HSC) or human PBMC, as well as the development of chimeric models harboring human immune checkpoint targets in immunocompetent mice. CrownBio has successfully established a number of human PBMC-humanized xenograft models known as MiXeno for in vivo immunotherapy evaluation. Our MiXeno platform is a rapid and simple strategy for model humanization. However, aspects such as the optimal PBMC injection route and cell number, the PBMC donor dependence and specificity, and the impact of donor HLA type on the engraftment of immune or tumor cells, etc., require fine tuning. After comparative studies for cell titration and immune cell reconstitution, the optimal inoculation conditions and protocols were established for each model. Immune cell constitution and tumor cell engraftment were synchronized so that graft versus host disease (GvHD) can be managed. Models were also characterized by immunophenotyping. MiXeno is proven as a valid alternative to other humanized mouse models, and has a broad spectrum of applications in immuno-oncology including the evaluation of human specific immuno-modulatory drugs in vivo.

Citation Format: Lan Zhang, Juan Zhang, Meng Qiao, Xuefei Yan, Jian Ding, Fei Chen, Xiaoyu An, WenQing Yang, Qian Shi. Validation and characterization of MiXeno humanized mouse models for immuno-oncology [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr B28.

Dispersive shock waves governed by the Whitham equation and their stability

Dispersive shock waves (DSWs), also termed undular bores in fluid mechanics, governed by the non-local Whitham equation are studied in order to investigate short wavelength effects that lead to peaked and cusped waves within the DSW. This is done by combining the weak nonlinearity of the Korteweg–de Vries equation with full linear dispersion relations. The dispersion relations considered are those for surface gravity waves, the intermediate long wave equation and a model dispersion relation introduced by Whitham to investigate the 120° peaked Stokes wave of highest amplitude. A dispersive shock fitting method is used to find the leading (solitary wave) and trailing (linear wave) edges of the DSW. This method is found to produce results in excellent agreement with numerical solutions up until the lead solitary wave of the DSW reaches its highest amplitude. Numerical solutions show that the DSWs for the water wave and Whitham peaking kernels become modulationally unstable and evolve into multi-phase wavetrains after a critical amplitude which is just below the DSW of maximum amplitude.

Abstract 1016: Transcriptomic analysis of bulk tissues of large PDX collection as a novel platform discovering new TME target/drug

Cancers are collections of diverse diseases of genetic and immunological abnormalities. The heterogeneous tumor microenvironment (TME), including immune components, and their interactions with tumor cells play critical roles in tumor progression and response to pharmaceutics, particularly immuno-oncology (I/O) therapy. However, investigating TME-specific components is rather challenging for the difficulty to separate stroma from tumor cells, either physically via microdissection or in silico via bioinformatics. Patient derived xenograft (PDX) may be a new system to investigate TME1, where human and mouse content can readily be separated in silico2. We have transcriptome-sequenced ~1600 bulk tumor tissues from subcutaneous PDXs grown in athymic mice3. By aligning reads to human and mouse genomes, we found that the average mouse-to-human sequencing read ratio is around 11% (5~20%), consistent with the previous report2. After removal of the low-expressed and less-variable genes and by deconvolution analysis of gene expression data, we identified all types of TME components, including adaptive and innate immune cells. The corresponding fractions vary across cancer types and individual models. Co-regulation analysis identified a huge number of intra-species interactions and also, a smaller number of inter-species interactions that vary greatly among different cancer types. The cross-species interactions observed are likely implicated in the growth of these tumors, and their numbers may also reveal the degree of the dependence of tumor growth on TME, which should be reversely correlated to the transplantation take-rate of corresponding type of PDX. Indeed, we have demonstrated this reverse-correlations (# interactions: take-rate %) with statistical-significance (p-value = 0.034) across our PDX collections, including melanoma (406:27%), lung (146:50%), colorectal (CRC) (157:68%) and pancreatic cancer (32:80%). The cancer type with the highest take-rate and lowest # interactions is pancreatic cancer that also has highest KRAS mutation rate (&gt;90%), hinting the role of KRAS mutation in tumor growth independency on TME. This is further confirmed in KRAS mutant CRC (1:96%) vs. wild-type (98:53%). Moreover, some putative cross-species co-regulations in specific cancers were also observed in human tumors (e.g. in TCGA dataset), indicating potential importance in TME-tumor interaction and tumor development in human. Further investigation of each of these interactions may reveal novel TME-related disease pathways and thus novel targeting strategy for cancer therapy. In conclusion, transcriptomic analysis of large number of bulk PDXs provides a novel and unique platform to study TME, likely to facilitate new discovery of disease pathways and strategy to treat cancers involving the TME mechanism, particularly I/O strategy.

Citation Format: Jia Xue, Wubin Qian, Sheng Guo, Xiaoyu An, Xuesong Ouyang, Henry Q. Li. Transcriptomic analysis of bulk tissues of large PDX collection as a novel platform discovering new TME target/drug [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1016.

Abstract 5677: Establishment and application of a panel of PBMC-humanized mouse tumor models in immune-oncology and targeted cancer immunotherapy

Background: Monoclonal antibodies and checkpoint blocking approaches have achieved remarkable success in cancer immunotherapy in clinical practices. Besides the success of anti-PD-1 and anti-PD-L1 antibodies (such as Keytrude and Tecentriq), two bispecific antibodies, Catumaxomab and Blinatumomab have been approved to treat cancer patients, and many more bispecific antibodies are currently in pre-clinical or clinical development. To meet the increasing market needs for fast, reliable and cost effective mouse tumor model systems, we developed a panel of humanized tumor models, designated as MiXenoTM platform. MiXenoTM could be used in a broad spectrum of applications in immuno-oncology drug discovery, including targeted cancer immune-therapy.

Method: CrownBio has a collection of about 200 xenograft models, including subcutaneous, orthotropic and systemic models, which covers majority of cancer type. Gene expression and mutation status are often profiled in these models. To engage both host immune system and tumor antigens, we have developed some specific MixenoTM tumor models by inoculating tumor cells over-expressing specific anti-tumor antigens (e.g. EGFR, CD47, Braf or PD-L1) into PBMC-humanized immunocompromised mice. Reconstitution of human immune component with human PBMCs in these tumor-bearing mice provides a useful tool to evaluate the targeted immune-therapeutics including bispecific T cell engagers.

Results: To validate the MiXenoTM models for targeted cancer immunotherapy, several xenograft models have been profiled and selected based on their tumor antigens or gene expression. Models with over-expression of a variety of tumor antigens (e.g. EGFR, CD47, Braf, PD-L1, etc.) were used to develop specific MixenoTM tumor models. The immune and tumor cells were engrafted either simultaneously or sequentially. Graft versus host disease (GvHD) can be managed by optimizing the immune cell constitution and tumor cell engraftment. Some models were also validated using stand of care I/O drugs and characterized by immune-phenotyping.

Conclusions: MiXenoTM tumor models with specific tumor antigen targeting strategy are valid model systems to evaluate the human immuno-modulatory drugs including bispecific antibodies. Further studies are needed to expand model collections and to extend their applications in I/O space.

Citation Format: Lan Zhang, Haochen Wu, Fei Chen, Lianqi Zhao, Xiaoyu An, Weibin Tan, Xiaoyan Fu, Meng Qiao, Qian Shi, Wenqing Yang. Establishment and application of a panel of PBMC-humanized mouse tumor models in immune-oncology and targeted cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5677.