Significant Reduction In Growth Research Articles

Abstract 2472: Inhibition of ENPP1 catalyzed ATP and cGAMP hydrolysis and in vivo antitumor efficacy of RBS2418 in the Hepa1-6 and GL261-luc syngeneic liver and glioblastoma mouse models

Abstract Background: ENPP1, a nucleotide pyrophosphatase and phosphodiesterase, has emerged as an important modulator of anti-tumor immune activation, as it regulates the concentrations of cGAMP and ATP in the TME. ENPP1 expression in tumors is common and correlates with a cold tumor phenotype. Its loss has been reported to suppress metastasis, restore immune cell infiltration into the tumor and potentiate the response to immune checkpoint blockade, while, conversely, the overexpression of ENPP1 promoted metastasis and rendered tumors resistant to checkpoint blockade. RBS2418 was designed as a potent and selective inhibitor of ENPP1 and is in clinical development. Methods: ENPP1 enzyme inhibition was measured in vitro using cGAMP and ATP substrates. Effects of pH and serum and selectivity against related enzymes were evaluated. In vivo efficacy was assessed in Hepa1-6, and GL261-luc syngeneic liver and glioblastoma mouse models. Compound exposures were determined in tumor and blood samples. Cures were confirmed by re-challenge of cured animals with the same cancer cells. Results: RBS2418 inhibited hydrolysis of cGAMP and ATP in vitro with similar potency (Ki =0.14 and 0.13 nM). Inhibition was also similar in human serum, consistent with low binding affinity to human serum albumin. In humans, oral dosing at doses of 100 mg could inhibit ENPP1 enzyme activity during the full dosing interval. Dosing of RBS2418 was performed in mice to achieve trough concentrations of RBS2418 in tumors and plasma exceeding ENPP1 EC90 levels for the complete dosing interval. In the Hepa1-6 model treatment with RBS2418 for either 2 or 10 days resulted in significant reduction of tumor growth and prolongation of survival as compared to vehicle control. There was no significant difference between the RBS2418 groups. Complete tumor regression was observed in 44% of treated mice across the two treatment groups. These mice were resistant to rechallenge with Hepa1-6 tumor cells. In the GL261-luc model treatment with RBS2418 showed significant reduction of tumor burden and prolongation of survival as compared to vehicle control. The mice that achieved complete tumor regression were resistant to rechallenge with GL261-luc tumor cells. Conclusions: RBS2418 inhibited ATP and cGAMP hydrolysis by ENPP1 with similar high potency. The pharmacology profile was optimized to achieve low serum protein binding and oral bioavailability in humans. RBS2418 treatment was well tolerated in mice under conditions where tumor and plasma levels exceeding ENPP1 serum EC90 levels were achieved. In the syngeneic mouse models Hepa1-6 and GL261-luc significant tumor growth reductions, complete tumor regression and cures were observed. Resistance to cancer cell rechallenge was consistent with treatment-induced anti-tumor immunity. Citation Format: Ningwu Huang, Junjun Cheng, Ron Hawley, Klaus Klumpp. Inhibition of ENPP1 catalyzed ATP and cGAMP hydrolysis and in vivo antitumor efficacy of RBS2418 in the Hepa1-6 and GL261-luc syngeneic liver and glioblastoma mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2472.

Abstract 2370: Revitalizing anti-tumor immunity through PLT012 monoclonal antibody, targeting CD36 for metabolic rewiring in the tumor microenvironment

Abstract The accumulation of lipid metabolic products in the TME has been extensively documented to exacerbate cancer malignancy by suppressing anti-tumor immunity. This phenomenon is characterized by the induction of immunosuppressive features in various immune cells and the development of exhausted phenotypes in T cells, creating formidable obstacles for effective immunotherapies. Notably, CD36, a fatty acid transporter, has been identified as up-regulated in both malignant cells and various tumor-associated immune cells, including regulatory T cells, tumor-associated macrophages, and CD8+ T cells. This upregulation serves to adjust the metabolic preferences of these cells, enabling adaptation to the lipid-enriched TME. CD36-mediated adaptation not only instigates alterations in metabolic regulations but also significantly influences immune cell properties, contributing to the establishment of an immunosuppressive TME. Consequently, it has been proposed that inhibiting CD36-mediated fatty acid uptake could strategically reshape the host's anti-tumor immunity within the TME, resulting in the reduction of tumor-infiltrating regulatory T cells and the restoration of both survival and functionality in CD8 T cells. These findings underscore the therapeutic potential of anti-CD36 antibodies as a targeted approach to mitigate the immunosuppressive milieu within the TME. Hence, PLT012, a humanized anti-CD36 antibody, was developed via phage display, followed by affinity maturation and developability optimization, and possesses cross-reactivity among species, including murine, non-human primates, and human. Through CryoEM-based structural analysis, we found that PLT012 recognizes the lipid binding domain of CD36 without interfering with the TSP-1 binding site. Moreover, administration of PLT012 significantly reduced oxLDL-mediated M2 macrophage polarization and fatty acid uptake in CD8+ TILs. Notably, HCC-bearing mice treated with PLT012 exhibited a significant reduction in tumor growth with an increased CD8/Treg ratio and CD8 effector functions, consistent with the ex vivo observations of PLT012 treatments in human HCC samples. In addition to murine studies, PLT012 also demonstrated excellent tolerability in NHP studies without any adverse effects. Ongoing studies in translational medicine will further bridge our findings and proposed mechanism of action with clinical observations, highlighting the potential therapeutic outcome in HCC patients particularly. Taken together, these results reveal that blocking CD36-mediated metabolic alterations in Treg and CD8+ TILs with PLT012 treatment can elicit robust tumor growth inhibition and shift the immunosuppressive nature within the TME toward an immunosupportive one. This study further provides the pillar for harnessing immunometabolic targeting in cancer immunotherapy. Citation Format: Yi-Ru Yu, Sheue-Fen Tzeng, Huey-Wen Hsiao, Jaeoh Park, Lana Kandalaft, Yun-Han Lin, Chin-Hsien Tsai, Ping-Chih Ho. Revitalizing anti-tumor immunity through PLT012 monoclonal antibody, targeting CD36 for metabolic rewiring in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2370.

Abstract 2737: LIS22, a first in class polyclonal antibody immunotherapy in T cell blood cancers

Abstract Background: Several approaches such as antibody drug conjugate (ADC), chimeric antigen receptor T cells (CAR-T) and recently bispecific antibodies are being introduced as innovative weapon in B-Cell lymphoma treatment. In the opposite, very limited therapeutic options are available for the treatment of rare refractory T cell malignancies such as PTCL. The 5-year survival rate of PTCL is lower than 30% according to the recent clinical data. Developing new effective treatment strategies for PTCL is an urgent problem. LIS22, is a first in class glyco-humanized polyclonal antibody (GH-pAb), targeting multiple tumor-associated antigens simultaneously. In this study, we characterized the safety and efficacy of LIS22 in preclinical models of T cell malignancies. Material and Methods: LIS22 ability to induce Antibody-Dependent Cell Cytotoxicity (ADCC), Antibody-Dependent Cellular Phagocytosis (ADCP), Complement Dependent Cytotoxicity (CDC), and apoptosis was tested in a panel of hematologic malignancy cell lines and peripheral blood mononuclear cell (PBMC). To assess the targeting and recognition of LIS22 in PTCL patients, we evaluated the immunolabelling of LIS22 on patients’ biopsies (n=119) using tissue microarray. LIS22 efficacy in vivo were evaluated in NMRI nude mice and SRG rats using T1301 and Jurkat cancer cell lines. Pharmacokinetics and safety of this drug were assessed in cynomolgus monkeys after single and repeated IV dosing up to 50mg/kg. Results: LIS22 acts via several mechanisms, at 30µg/ml, it induced cytotoxicity via CDC (in 70%), ADCP (in 49%), ADCC (in 41%) and apoptosis (in 30%) of HPB-ALL human T blood cancer cell line but not in PBMC. LIS22 showed a potent in vitro antitumor activity in a panel of hematologic malignancy cell lines, it induced specific tumor cell CDC (EC50=41.4±28.9µg/mL). In both CDC and apoptosis cytotoxicity assays, LIS22 displayed a significantly higher potency on T cell blood cancers and no toxicity on healthy blood cells compared to PTCL clinically active drug Alemtuzumab (Anti-CD52). It was able to kill up to 100% of the cancer cells without affecting PBMC. In immunolabeling assay, LIS22 demonstrated cross-reaction to PTCL patient biopsy (staining up to 93%). In vivo efficacy studies in different mice and rat xenograft models, LIS22 induced a significant reduction of tumor growth up to 90% across several tested tumors. LIS22 was also characterized by high tolerance profile and satisfactory exposure in monkeys after repeated dosing (up to 250mg/kg of cumulative dose). Conclusion: LIS22 appeared as a novel and promising cancer immunotherapy against T Cell hematologic malignancies. It has already been administered to human in another indication and showed a satisfactory PK and safety profile (no signs of immunotoxicity or systemic cytokine release). LIS22 is now ready to enter Phase I/II in the coming months for the treatment of peripheral T cell lymphoma (PTCL). Citation Format: Carine Ciron, Francoise Shneiker, Ophélie Dauphouy, Juliette Rousse, Pierre-Joseph Royer, Gwenaelle Evanno, Odile Duvaux, Firas Bassissi. LIS22, a first in class polyclonal antibody immunotherapy in T cell blood cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2737.

Abstract 4058: Nanoparticle delivery of interleukin-2 induces anti-tumor immune response and therapeutic efficacy in mouse tumor models

Abstract Immune checkpoint inhibitors (ICIs) have demonstrated robust responses in some solid tumor types. However, the low response rate, which is associated with lack of pre-existing tumor-infiltrating lymphocytes (TILs), remains a significant challenge. Interleukin-2 (IL-2) can effectively expand TILs and has been FDA-approved for metastatic renal cancer and melanoma. However, IL-2 has several drawbacks—including short circulation half-life, dose-limiting toxicities, and counterproductive activation of regulatory T cells (Tregs)—resulting in less than 10% complete response rate. Numerous efforts have been made to enhance IL-2 formulations, but none have yet received FDA approval. In this study, we utilized our proprietary nanoparticle platform (Pdx-NP™) to improve IL-2 formulation. Pdx-NP™ can load IL-2 with near-complete binding, resulting in a 160-nm nanoconstruct (IL2-NP), suitable for both local and intravenous administrations. To evaluate the efficacy, we utilized bilateral melanoma (B16F10) and colon (MC38) tumor models, in which the local tumor was treated intratumorally for 3 doses and the distal tumor was left untreated to assess the systemic anti-tumor immune response. In the B16F10 model, IL2-NP treatment demonstrated favorable immune profiles in local and distal tumors and the draining lymph nodes, such as increased CD8+ T cell proliferation, CD8+ T cells/Treg ratio, and recruitment of dendritic cells and macrophages, compared to saline or free IL-2 counterparts. These positive immune responses translated into significant growth reduction of IL2-NP treated tumors and improvement in survival of the mice compared to free IL-2. In the MC38 tumor model, the IL2-NP treatment resulted in complete regression of both local and distal tumors in 43% of the mice. When combined with ICIs (αPD-1 and αCTLA-4), the treatment achieved a cure rate of 100%, whereas ICIs alone yielded only a 29% cure rate. In conclusion, IL2-NP induces robust proliferation and activation of TILs and is efficacious both as a monotherapy and in combination with ICIs. This is due to the ability of Pdx-NP™ to protect and retain therapeutics within tumors, with an 8-fold increase in tumor accumulation over the free drug counterpart. Our ongoing efforts are focused on the targeted delivery of IL-2 to tumors upon systemic administration, using αPD-L1 antibody-conjugated Pdx-NP™. This antibody-conjugated nanoparticle has an elimination half-life (t1/2) of about 25 hrs in non-human primates. Paired with αPD-L1 for tumor homing, this nanoconstruct is hypothesized to enhance IL-2 accumulation in tumors compared to free IL-2, which has t1/2 of only 1.5 hrs in human. The current clinical landscape of cancer immunotherapy focuses on combinational approaches, and our versatile Pdx-NP™ platform, which is capable of co-delivering different classes of therapeutics, is well suited for this endeavor. Citation Format: Ruijie Wang, Alyssa Wallstrum, Natalie White, Pramod Kumar, Tongchatra Watcharawittayakul, Noah A. Crumrine, Cole Baker, Jeremy Saito, Moataz Reda, Worapol Ngamcherdtrakul, Wassana Yantasee. Nanoparticle delivery of interleukin-2 induces anti-tumor immune response and therapeutic efficacy in mouse tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4058.

Abstract 6588: Discovery of ASTX295, a potent, next-generation small molecule antagonist of MDM2 with differentiated pharmacokinetic profile

Abstract In response to cellular stress, the tumor suppressor p53 is activated to modulate cell cycle progression, DNA repair, and apoptosis. Inhibition of the MDM2-p53 interaction in tumors carrying wild-type p53 prevents its degradation and can reactivate p53 to elicit an anti-cancer effect. Targeting the p53-MDM2 interaction therefore remains a promising strategy for cancer therapy. However, development of first generation MDM2 antagonists has been challenged by dose-limiting, on-target bone marrow toxicities. Understanding of differential effects of p53 pathway activation in normal hematopoietic versus cancer cells (to be presented in a separate abstract) together with our expertise in structure-based drug design have led to the discovery of ASTX295, a potent MDM2 antagonist with differentiated pharmacokinetic profile aimed at sparing bone marrow toxicities and increasing the therapeutic index. Here, we present the first disclosure of the structure and pre-clinical characterisation of ASTX295. ASTX295 exhibits potent activity (IC50<1 nM) against MDM2 in an ELISA-based in vitro assay and induces significant growth reduction in p53 wild-type, MDM2-amplified SJSA-1 cells (GI50=27 nM). Antiproliferative activity of ASTX295 was further demonstrated in a panel of 219 p53 wild-type cell lines, with 143 cell lines showing GI50 values less than 1 μM and 50 showing values less than 0.1 μM. Effects of ASTX295 are shown in cell lines carrying functional p53 as confirmed in three p53 wild-type and mutant cell line pairs (SJSA1 and SN40R2, A2780 and A2780CP, HCT116 and HCT116 p53−/−). In addition to inhibiting cell cycle progression and cell proliferation, ASTX295 also potently induces apoptosis following 24-48 hour treatment. Further in vitro analyses of ASTX295 demonstrated an increase in the levels of p53 (EC50=10 nM after 2 hours) and its transcriptional targets such as p21 and MDM2. In vivo, ASTX295 shows robust induction of p53 and its target genes at 3 and 6 hours after oral administration together with dose-dependent inhibition of tumour growth in the SJSA-1 xenograft model. Importantly, ASTX295 exhibits optimised pharmacokinetic and pharmacodynamic profiles with relatively short duration of pathway modulation and a desired predicted human half-life of 2-8 hours. Based on our pre-clinical hypothesis on differential time-dependent sensitivities of normal versus cancer cells to p53 activation, achieving such a profile while maintaining potency may increase the therapeutic index. These data highlight the therapeutic potential of ASTX295, which is currently being tested in a Phase 1/2 clinical trial in advanced solid tumors with wild-type p53 (NCT03975387). We plan to present preliminary clinical data in a separate abstract at this meeting. Citation Format: Maria Ahn, Luke Bevan, Ildiko Buck, Celine Cano, Juan Castro, Ben Cons, Jane Endicott, Lynsey Fazal, Nicola Ferrari, Ian Hardcastle, Keisha Hearn, Rhian Holvey, Steven Howard, Chris Johnson, Claire Jennings, Justyna Kucia-Tran, Suzanne Kyle, John Lunec, John Lyons, Duncan Miller, David Rees, Martin Noble, David R. Newell, Judith Reeks, Harpreet Saini, Jeffrey St. Denis, Emiliano Tamanini, Huw Thomas, Neil Thompson, Mladen Vinkovic, George Ward, Nicola Wallis, Hugh Walton, Stephen Wedge, Pamela Williams, Elaine Willmore, Nicola Wilshire, Yan Zhao, Gianni Chessari. Discovery of ASTX295, a potent, next-generation small molecule antagonist of MDM2 with differentiated pharmacokinetic profile [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6588.

MoNOT3 Subunit Has Important Roles in Infection-Related Development and Stress Responses in Magnaporthe oryzae.

The multifunctional carbon catabolite repression negative on TATA-box-less complex (CCR4-NOT) is a multi-subunit complex present in all eukaryotes, including fungi. This complex plays an essential role in gene expression; however, a functional study of the CCR4-NOT complex in the rice blast fungus Magnaporthe oryzae has not been conducted. Seven genes encoding the putative CCR4-NOT complex were identified in the M. oryzae genome. Among these, a homologous gene, MoNOT3, was overexpressed during appressorium development in a previous study. Deletion of MoNOT3 in M. oryzae resulted in a significant reduction in hyphal growth, conidiation, abnormal septation in conidia, conidial germination, and appressorium formation compared to the wild-type. Transcriptional analyses suggest that the MoNOT3 gene affects conidiation and conidial morphology by regulating COS1 and COM1 in M. oryzae. Furthermore, Δmonot3 exhibited a lack of pathogenicity, both with and without wounding, which is attributable to deficiencies in the development of invasive growth in planta. This result was also observed in onion epidermal cells, which are non-host plants. In addition, the MoNOT3 gene was involved in cell wall stress responses and heat shock. Taken together, these observations suggest that the MoNOT3 gene is required for fungal infection-related cell development and stress responses in M. oryzae.

H3K4 methylation regulates development, DNA repair, and virulence in Mucorales

Mucorales are basal fungi that opportunistically cause a potentially fatal infection known as mucormycosis (black fungus disease), which poses a significant threat to human health due to its high mortality rate and its recent association with SARS-CoV-2 infections. On the other hand, histone methylation is a regulatory mechanism with pleiotropic effects, including the virulence of several pathogenic fungi. However, the role of epigenetic changes at the histone level never has been studied in Mucorales. Here, we dissected the functional role of Set1, a histone methyltransferase that catalyzes the methylation of H3K4, which is associated with the activation of gene transcription and virulence. A comparative analysis of the Mucor lusitanicus genome (previously known as Mucor circinelloides f. lusitanicus) identified only one homolog of Set1 from Candida albicans and Saccharomyces cerevisiae that contains the typical SET domain. Knockout strains in the gene set1 lacked H3K4 monomethylation, dimethylation, and trimethylation enzymatic activities. These strains also showed a significant reduction in vegetative growth and sporulation. Additionally, set1 null strains were more sensitive to SDS, EMS, and UV light, indicating severe impairment in the repair process of the cell wall and DNA lesions and a correlation between Set1 and these processes. During pathogen-host interactions, strains lacking the set1 gene exhibited shortened polar growth within the phagosome and attenuated virulence both in vitro and in vivo. Our findings suggest that the histone methyltransferase Set1 coordinates several cell processes related to the pathogenesis of M. lusitanicus and may be an important target for future therapeutic strategies against mucormycosis.

The antitumor effects of herbal medicine Triphala on oral cancer by inactivating PI3K/Akt signaling pathway: based on the network pharmacology, molecular docking, in vitro and in vivo experimental validation

BackgroundThis research aimed to investigate the anti-tumor effects and underlying genetic mechanisms of herbal medicine Triphala (TRP) in oral squamous cell carcinoma (OSCC). MethodsThe target genes of Triphala (TRP) in oral squamous cell carcinoma (OSCC) were identified, and subsequent functional enrichment analysis was conducted to determine the enriched signaling pathways. Based on these genes, a protein-protein interaction network was constructed to identify the top 10 genes with the highest degree. Genes deregulated in OSCC tumor samples were identified to be hub genes among the top 10 genes. In vitro experiments were performed to investigate the influence of TRP extracts on the cell metabolic activity, migration, invasion, apoptosis, and proliferation of two OSCC cell lines (CAL-27 and SCC-9). The functional rescue assay was conducted to investigate the effect of applying the inhibitor and activator of an enriched pathway on the phenotypes of cancer cells. In addition, the zebrafish xenograft tumor model was established to investigate the influence of TRP extracts on tumor growth and metastasis in vivo. ResultsThe target genes of TRP in OSCC were prominently enriched in the PI3K-Akt signaling pathway, with the identification of five hub genes (JUN, EGFR, ESR1, RELA, and AKT1). TRP extracts significantly inhibited cell metabolic activity, migration, invasion, and proliferation and promoted cell apoptosis in OSCC cells. Notably, the application of TRP extracts exhibited the capacity to downregulate mRNA and phosphorylated protein levels of AKT1 and ESR1, while concomitantly inducing upregulation of mRNA and phosphorylated protein levels in the remaining three hub genes (EGFR, JUN, and RELA). The functional rescue assay demonstrated that the co-administration of TRP and the PI3K activator 740Y-P effectively reversed the impact of TRP on the phenotypes of OSCC cells. Conversely, the combination of TRP and the PI3K inhibitor LY294002 further enhanced the effect of TRP on the phenotypes of OSCC cells. Remarkably, treatment with TRP in zebrafish xenograft models demonstrated a significant reduction in both tumor growth and metastatic spread. ConclusionsTriphala exerted significant inhibitory effects on cell metabolic activity, migration, invasion, and proliferation in OSCC cell lines, accompanied by the induction of apoptosis, which was mediated through the inactivation of the PI3K/Akt pathway.

Disruption of cyclin D1 degradation leads to the development of mantle cell lymphoma

Cyclin D1 has been recognized as an oncogene due to its abnormal upregulation in different types of cancers. Here, we demonstrated that cyclin D1 is SUMOylated, and we identified Itch as a specific E3 ligase recognizing SUMOylated cyclin D1 and mediating SUMO-induced ubiquitination and proteasome degradation of cyclin D1. We generated cyclin D1 mutant mice with mutations in the SUMOylation site, phosphorylation site, or both sites of cyclin D1, and found that double mutant mice developed a Mantle cell lymphoma (MCL)-like phenotype. We showed that arsenic trioxide (ATO) enhances cyclin D1 SUMOylation-mediated degradation through inhibition of cyclin D1 deSUMOylation enzymes, leading to MCL cell apoptosis. Treatment of severe combined immunodeficiency (SCID) mice grafted with MCL cells with ATO resulted in a significant reduction in tumor growth. In this study, we provide novel insights into the mechanisms of MCL tumor development and cyclin D1 regulation and discover a new strategy for MCL treatment.

Radiosensitization of Allogenic Subcutaneous C6 Glioma Model with Focused Ultrasound-Induced Mild Hyperthermia.

The radiosensitization potential of focused ultrasound (FUS)-induced mild hyperthermia was assessed in an allogenic subcutaneous C6 glioma tumor model in rats. Mild hyperthermia at 42 °C was induced in tumors using a single-element 350 kHz FUS transducer. Radiation was delivered with a small animal radiation research platform using a single-beam irradiation technique. The combined treatment involved 20 min of FUS hyperthermia immediately before radiation. Tumor growth changes were observed one week post-treatment. A radiation dose of 2 Gy alone showed limited tumor control (30% reduction). However, when combined with FUS hyperthermia, there was a significant reduction in tumor growth compared to other treatments (tumor volumes: control-1174 ± 554 mm3, FUS-HT-1483 ± 702 mm3, 2 Gy-609 ± 300 mm3, FUS-HT + 2 Gy-259 ± 186 mm3; ANOVA p < 0.00001). Immunohistological analysis suggested increased DNA damage as a short-term mechanism for tumor control in the combined treatment. In conclusion, FUS-induced mild hyperthermia can enhance the effectiveness of radiation in a glioma tumor model, potentially improving the outcome of standard radiation treatments for better tumor control.

Identification and pathogenicity of Fusarium species associated with wilting and crown rot in almond (Prunus dulcis)

Severe Fusarium wilt and crown root symptoms were observed in almond orchards in Portugal. The present study elucidates the etiology of the disease through molecular, phenotypic, and pathogenic characterization. Three Fusarium isolates from Portugal were tested and 12 Fusarium isolates from almond from Spain were included for comparative purposes. Their identity was inferred by phylogenetic analysis combining tef1 and rpb2 sequences. The Portuguese isolates were identified as Fusarium oxysporum sensu stricto (s.s.), and the Spanish isolates as Fusarium nirenbergiae, F. oxysporum (s.s.), Fusarium proliferatum, Fusarium redolens (s.s.), Fusarium sambucinum (s.s.), and Fusarium sp. Fungal colonies and conidia were characterized on potato dextrose agar (PDA) and on Synthetischer Nährstoffarmer agar, respectively. The colonies had a variable morphology and their color ranged from white to pale violet. Typical Fusarium micro- and macroconidia were characterized. Temperature effect on mycelial growth was evaluated on PDA from 5 to 35 °C, with optimal growth temperature ranging between 16.8 and 26.4 °C. The pathogenicity of F. oxysporum was demonstrated by inoculating almond plants (‘Lauranne’) grafted on GF-677 or Rootpac 20 rootstocks. A significant reduction in plant growth, wilting, and xylem discoloration was observed, with Rootpac 20 being more susceptible than GF-677. Infections were also reproduced using naturally infested soils. Almond plants (‘Lauranne’) were inoculated with isolates of all Fusarium species, with F. redolens from Spain and F. oxysporum from Portugal being the most aggressive.

Therapeutic efficacy of tranexamic acid on traumatic brain injury: a systematic review and meta-analysis

ObjectiveTranexamic acid (TXA) demonstrates therapeutic efficacy in the management of traumatic brain injury (TBI). The objective of this systematic review and meta-analysis was to evaluate the safety and effectiveness of TXA in patients with TBI.MethodsThe databases, namely PubMed, Embase, Web of Science, and Cochrane Library databases, were systematically searched to retrieve randomized controlled trials (RCTs) investigating the efficacy of TXA for TBI from January 2000 to November 2023.ResultsThe present meta-analysis incorporates ten RCTs. Compared to the placebo group, administration of TXA in patients with TBI resulted in a significant reduction in mortality (P = 0.05), hemorrhage growth (P = 0.03), and volume of hemorrhage growth (P = 0.003). However, no significant impact was observed on neurosurgery outcomes (P = 0.25), seizure occurrence (P = 0.78), or pulmonary embolism incidence (P = 0.52).ConclusionThe administration of TXA is significantly associated with reduced mortality and hemorrhage growth in patients suffering from TBI, while the need of neurosurgery, seizures, and incidence of pulmonary embolism remains comparable to that observed with placebo.

Impact of predicted climate change environmental conditions on the growth of Fusarium asiaticum strains and mycotoxins production on a wheat-based matrix

Fusarium asiaticum is a predominant fungal pathogen causing Fusarium Head Blight (FHB) in wheat and barley in China and is associated with approximately £201 million in annual losses due to grains contaminated with mycotoxins. F. asiaticum produces deoxynivalenol and zearalenone whose maximum limits in cereals and cereals-derived products have been established in different countries including the EU. Few studies are available on the ecophysiological behaviour of this fungal pathogen, but nothing is known about the impact of projected climate change scenarios on its growth and mycotoxin production. Therefore, this study aimed to examine the interacting effect of i) current and increased temperature (25 vs 30 °C), ii) drought stress variation (0.98 vs 0.95 water activity; aw) and iii) existing and predicted CO2 concentrations (400 vs 1000 ppm) on fungal growth and mycotoxin production (type B trichothecenes and zearalenone) by three F. asiaticum strains (CH024b, 82, 0982) on a wheat-based matrix after 10 days of incubation. The results showed that, when exposed to increased CO2 concentration (1000 ppm) there was a significant reduction of fungal growth compared to current concentration (400 ppm) both at 25 and 30 °C, especially at 0.95 aw. The multi-mycotoxin analysis performed by LC-MS/MS qTRAP showed a significant increase of deoxynivalenol and 15-acetyldeoxynivalenol production when the CH024b strain was exposed to elevated CO2 compared to current CO2 levels. Zearalenone production by the strain 0982 was significantly stimulated by mild water stress (0.95 aw) and increased CO2 concentration (1000 ppm) regardless of the temperature. Such results highlight that intraspecies variability exist among F. asiaticum strains with some mycotoxins likely to exceed current EU legislative limits under prospected climate change conditions.

Impact of lead and zinc heavy metal pollution on the growth and phytoremediation potential of Sulla carnosa in Sebkha el Kalbia, Tunisia.

Heavy metal pollution from human and natural activities poses significant environmental and health concerns for wildlife and humans, with lead and zinc being particularly threatening. This study focuses on Sebkha el Kalbia in Tunisia, highlighting the challenges faced by local communities in addressing heavy metal pollution. The area is prone to contamination through rivers and streams that transport pollutants from industrial zones and rural areas into the salt pan. The recent establishment of an industrial zone has worsened pollution levels, calling for strict regulatory measures and clean technologies to limit heavy metal pollution and protect human health and the environment. The study assesses the impact of lead and zinc pollution on the growth of Sulla carnosa and its potential for phytoremediation. Soil and plant samples from contaminated areas were analyzed, revealing high levels of heavy metal contamination. The growth parameters of Sulla carnosa, such as plant height, weight, and enzymatic activity, were examined, showing a significant reduction in plant growth when exposed to high metal concentrations. Specifically, in the presence of 100ppm of lead (Pb), net photosynthetic assimilation (An) decreased by 52%, while the amount of Pb increased by 78%. At 800ppm of Pb, An decreased by 87%, and the amount of Pb increased by over 800%. Furthermore, the relationship between net photosynthetic assimilation and lead (Pb) content remained significant but negative. At high doses (800ppm), the biomass produced decreases by 64%, while the amount of Zn increases 2.7 times. These results suggest that at low doses, zinc is not toxic. These findings highlight Sulla carnosa as a potential candidate for phytoremediation with preferential metal accumulation in the roots and improved enzymatic activity, underscoring the urgency of addressing heavy metal pollution in Sebkha el Kalbia.

Fractional extraction of lignin from coffee beans with low cytotoxicity, excellent anticancer and antioxidant activities

Lignin, a biopolymer generated from renewable resources, is widely present in terrestrial plants and possesses notable biosafety characteristics. The objective of this work was to assess the edible safety, in vitro antioxidant, and anti-cancer properties of various lignin fractions isolated from commercially available coffee beans often used for coffee preparation. The findings suggest that the phenolic hydroxyl content increased from 3.26 mmol/g (ED70L) to 5.81 mmol/g (ED0L) with decreasing molecular weight, which resulted in more significant antioxidant properties of the low molecular weight lignin fraction. The findings of the study indicate that the viability of RAW 264.7 and HaCaT cells decreased as the quantity of lignin fractions increased. It was observed that concentrations below 200 μg/mL did not exhibit any harmful effects on normal cells. The results of the study demonstrated a significant reduction of cancer cell growth (specifically A375 cells) at a concentration of 800 μg/mL for all lignin fractions, with an observed inhibition rate of 95 %. The results of this study indicate that the lignin extracts derived from coffee beans exhibit significant potential in mitigating diseases resulting from excessive radical production. Furthermore, these extracts show promise as natural antioxidants and anti-cancer agents.

Pyridoxal kinase gene deletion leads to impaired growth, deranged redox metabolism and cell cycle arrest in Leishmania donovani

Pyridoxal kinase (PdxK) is a vitamin B6 salvage pathway enzyme which produces pyridoxal phosphate. We have investigated the impact of PdxK deletion in Leishmania donovani on parasite survivability, infectivity and cellular metabolism. LdPdxK mutants were generated by gene replacement strategy. All mutants showed significant reduction in growth in comparison to wild type. For PdxK mediated biochemical perturbations, only heterozygous mutants and complementation mutants were used as the growth of null mutants were compromised. Heterozygous mutant showed reduction invitro infectivity and higher cytosolic and mitochondrial ROS levels. Glutathione levels decreased significantly in heterozygous mutant indicating its involvement in cellular oxidative metabolism. Pyridoxal kinase gene deletion resulted in reduced ATP levels in parasites and arrest at G0/G1 phase of cell cycle. All these perturbations were rescued by PdxK gene complementation. This is the first report to confirm that LdPdxK plays an indispensable role in cell survival, pathogenicity, redox metabolism and cell cycle progression of L. donovani parasites. These results provide substantial evidence supporting PdxK as a therapeutic target for the development of specific antileishmanial drug candidates.

Potent induction of trained immunity by Saccharomyces cerevisiae β-glucans.

Candida albicans cell wall component β-glucan has been extensively studied for its ability to induce epigenetic and functional reprogramming of innate immune cells, a process termed trained immunity. We show that a high-complexity blend of two individual β-glucans from Saccharomyces cerevisiae possesses strong bioactivity, resulting in an enhanced trained innate immune response by human primary monocytes. The training required the Dectin-1/CR3, TLR4, and MMR receptors, as well as the Raf-1, Syk, and PI3K downstream signaling molecules. By activating multiple receptors and downstream signaling pathways, the components of this β-glucan preparation are able to act synergistically, causing a robust secondary response upon an unrelated challenge. In in-vivo murine models of melanoma and bladder cell carcinoma, pre-treatment of mice with the β-glucan preparation led to a significant reduction in tumor growth. These insights may aid in the development of future therapies based on β-glucan structures that induce an effective trained immunity response.

Stimuli-responsive magnetic silica-poly-lactic-co-glycolic acid hybrid nanoparticles for targeted cancer chemo-immunotherapy.

Chemotherapy and immunotherapy are two important modalities in cancer management. However, due to multiple reasons, a monotherapy is only partially effective. Hence, if used concurrently in targeted and stimuli-responsive manner, it could have been superior therapeutically. To facilitate co-delivery of chemotherapeutic and immunotherapeutic agent to the target cancer cells, engineered nanoparticles, i.e., a pH-responsive polymer PLGA-coated magnetic silica nanoparticles (Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs) encapsulating paclitaxel (PTX) and siRNA against programmed cell death ligand-1 (PD-L1) are synthesized and characterized. Developed nanoparticles demonstrated pH-sensitive sustained drug release up to 10 days. In vitro 4T1 cell line studies showed efficient cellular uptake, PD-L1 gene downregulation, and apoptosis. Further, in vivo efficacy studies carried out in the mice model demonstrated a significant reduction of tumor growth following treatment with dual-Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs as compared with monotherapy with Fe3O4-SiO2-PLGA-PDA-PTX NPs. The high therapeutic efficacy observed with dual-Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs was mainly due to the cytotoxic effect of PTX combined with targeted silencing of the gene of interest, i.e., PD-L1, which in turn improve CD8+ T cell-mediated cancer cell death as evident with increased proliferation of CD8+ T cells in co-culture experiments. Thereby, dual-Fe3O4-SiO2-PLGA-PDA-PTX-siRNA NPs may have a promising anti-cancer treatment potential against breast cancer; however, the beneficial effects of dual loading of PTX + PD-L1 siRNA may be corroborated against other cancer models such as lung and colorectal cancer models as well as in clinical trials.

Future impacts of climate change on black spruce growth and mortality: review and challenges

Black spruce ( Picea mariana (Mill.) B.S.P.) is the dominant conifer species across a large part of North American boreal forests, providing many goods and services essential to human activities, and playing a major climatic role through the global carbon cycle. However, a comprehensive synthesis of the effects of climate change on black spruce has not yet been undertaken. The dynamics of black spruce are influenced by various living (biotic) and non-living (abiotic) factors, as well as their combined effects, which are particularly responsive to changes in climate. Climate change predictions suggest that northern ecosystems will experience the world's most significant impact. Therefore, black spruce is likely to undergo profound disruptions in its growth and mortality rate in the next few decades, resulting in significant changes in forestry and carbon storage. However, these changes will not be uniform throughout the entire distribution of the species. Future changes in temperature and precipitation will create more stress for water availability in the boreal forests of western and central North America than in their eastern counterparts. Thus, significant longitudinal and latitudinal gradients in tree growth and mortality variability are expected throughout the range of the species. This literature review aims to summarise the impacts of climate change on individual tree growth and mortality of this major species. While enhanced black spruce productivity could occur through both increased air temperature and nitrogen mineralisation in the soil, moisture limitation in central and western North America will result in significant growth reduction and mortality events across these regions. Conversely, under the expected climate change scenarios, black spruce forests may be more resilient in eastern North America, where climatic conditions appear more suitable, particularly in their northernmost range. In this review, we identify current research gaps for some disturbances, which should be addressed to better understand the impact of climate change on black spruce. Finally, we identify issues associated with sustainable forest management and the maintenance of black spruce under projected future climate changes.

Abstract A036: Macropinocytosis mediates metabolic resistance to loss of glutamine transport in triple-negative breast cancer

Abstract Introduction Although a nonessential amino acid in normal cells, the demand for glutamine is dramatically increased throughout malignant transformation, supporting a range of metabolic processes including mitochondrial ATP production, protein synthesis, purine and pyrimidine biosynthesis. We previously shown that triple-negative breast cancer (TNBC) cells rely on glutamine uptake by the amino acid transporter ASCT2 to sustain their unique glutamine metabolism, thereby supporting in vitro growth and in vivo tumour formation. However, it is known that TNBC cells can also utilise non-transporter mediated nutrient uptake facilitated by processes such as macropinocytosis. Methods We examined proliferation of human breast cancer cell lines after ASCT2 CRISPR/Cas9 knockout (clonal and polyclonal populations) and shRNA knockdown. Proteomics and mRNAseq analysis further examined cellular and adaptive changes to ASCT2 knockout. Cellular changes were further analysed by western blotting, with macropinocytosis examined using 70kDa dextran-FITC uptake. Metabolic changes were assessed using targeted metabolomics approaches including 13C-labelled substrate tracing and liquid chromatography coupled tandem-mass spectrometry (LC-MS/MS) to determine intracellular levels of key tricarboxylic acid (TCA) cycle intermediates, glycolytic metabolites, fatty acid precursors, nucleotides, and amino acids in human TNBC cell lines in vitro. Results Despite our previous data showing a significant reduction in cell growth after ASCT2 knockdown, ASCT2 knockout was well-tolerated by both TNBC and Luminal A breast cancer cell lines, with proliferation rates similar to non-targeted CRISPR/Cas9 control cells. This adaptation to ASCT2 knockout was not due to the high glutamine levels present in culture media, as the knockout cells could be cloned in media containing either standard 2 mM glutamine or physiological 0.5 mM glutamine. Previous data have shown that TNBC cell lines can undergo constitutive macropinocytosis, and that this can be enhanced when cells are cultured in low nutrient conditions. Indeed, not only did the TNBC cell line HCC1806 undergo constitutive macropinocytosis, the amount of macropinocytosis was significantly increased (5-10 fold) in 5 separate ASCT2 knockout clones tested. By comparison, the ASCT2 shRNA knockdown cell line, which are published to have a significant proliferation deficit, showed a modest 2-fold increase in macropinocytosis, which may explain why they maintain a growth phenotype compared to the knockout lines. Despite in-depth analysis of gene and protein levels by mRNAseq and proteomics, ASCT2 knockout cells showed only a few significant changes in known macropinocytotic genes. There was, however, a substantial upregulation of Ser473-Akt phosphorylation which may drive the adaptive macropinocytosis in TNBC. Conclusion These data suggest that the constitutive macropinocytosis present in TNBC cell lines provides a novel resistance mechanism to strategies targeting glutamine uptake alone. Citation Format: Kanu Wahi, Natasha Freidman, Qian Wang, Yi Fang Guan, Jeff Holst. Macropinocytosis mediates metabolic resistance to loss of glutamine transport in triple-negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A036.