Significant Reduction In Growth Research Articles

Modeling Irrigation of Tomatoes with Saline Water in Semi-Arid Conditions Using Hydrus-1D

In arid and semi-arid regions like Tunisia, irrigation water is typically saline, posing a risk of soil and crop salinization and yield reduction. This research aims to study the combined effects of soil matric and osmotic potential stresses on tomato root water uptake. Plants were grown in pot and field experiments in loamy-clay soils and were irrigated with three different irrigation water qualities: 0, 3.5, and 7 dS/m. The Hydrus-1D model was used to simulate the combined dynamics of subsurface soil water and salts. Successful calibration and validation of the model against measured water and salt profiles enabled the examination of the combined effects of osmotic and matric potential stresses on root water uptake. Relative yields, indirectly estimated from actual and potential transpiration, indicated that the multiplicative stress response model effectively simulated the measured yields and the impact of saline water irrigation on crop yields. The experimental and modeling results provide information to aid in determining the salinity levels conducive to optimal crop growth. The findings indicate that the selected salinity levels affect tomato growth to varying degrees. Specifically, the salinity levels conducive to optimal tomato growth were between 0 and 3.5 dS/m, with a significant growth reduction above this salinity level. The gradual salinization of the root zone further evidenced this effect. The scenario considering a temperature increase of 2 °C had no significant impact on crop yields in the pot and field experiments.

Microfluidic-Based dsRNA Delivery Nanoplatform for Efficient Spodoptera exigua Control.

Nanotechnology-based RNA interference (RNAi) offers a promising approach to pest control. However, current methods for producing RNAi nanopesticides are mainly implemented in a batch-to-batch manner, lacking consistent quality control. Herein, we present a microfluidic-based nanoplatform for RNA nanopesticide preparation using lipid nanoparticles (LNPs) as nanocarriers, taking advantage of the enhanced mass transfer and continuous processing capabilities of microfluidic technology. The dsRNA@LNPs were rapidly formed within seconds, which showed uniform size distribution, improved leaf wettability, and excellent dispersion properties. The delivery efficiency of dsRNA@LNPs was evaluated by targeting the chitin synthetase B (CHSB) gene ofSpodoptera exigua. The dsRNA@LNPs can effectively resist nuclease-rich midgut fluid degradation. Importantly, dsCHSB@LNPs exhibited increased mortality rates, significant reduction of larvae growth, and enhanced gene suppression efficiency. Therefore, a continuous nanoplatform for RNAi nanopesticide preparation is demonstrated by utilizing microfluidic technology, representing a new route to produce RNAi nanopesticides with enhanced quality control and might accelerate their practical applications.

Exploring Melezitose as a Potential Therapeutic Agent in Lung Cancer: Inhibitory Effects on Cell Proliferation and EMT-Mediated Signaling in A549 Cells

Background Lung cancer is one of the most common cancers worldwide and a leading cause of cancer-related deaths. The study delves into melezitose, a naturally occurring compound known for its biocompatibility. Purpose This study aims to uncover its therapeutic potential and molecular mechanisms within lung cancer, particularly in A549 cells. Melezitose’s impact on inhibiting cell proliferation and influencing epithelial-mesenchymal transitions (EMT) was the primary focus. Material and Methods In a time-dependent manner, A549 cells, representative of lung adenocarcinoma (LUAD), underwent melezitose treatment. Analysis of cytotoxicity by MTT assay, cell migration assay, and its responsible genes were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) kit method. Results The MTT assay indicated a significant reduction in A549 cell growth after 48 hours of melezitose treatment. Additionally, melezitose induced G1 phase cell arrest and stimulated apoptosis in A549 cells. Subsequent determination of IC50 values represents the concentration at which melezitose inhibits 50% of cell growth. The study also investigated EMT-related gene expression like claudin 1 (CLD1), E-cadherin (ECADH), SNAIL1, SLUG, and vimentin (VIM) through RT-PCR. The findings revealed strong binding associations between melezitose and these EMT targets, suggesting a potential regulatory role of melezitose in impeding EMT processes. Conclusion Overall, this study illuminates the significant role of melezitose in lung cancer. Its observed inhibition of lung cancer cell proliferation and its influential impact on EMT-related gene expression highlights. Melezitose has potential as a therapeutic agent, particularly in the context of NSCC. The multifaceted effects of melezitose on A549 cells open promising avenues for advancing our understanding of this disease and developing innovative therapeutic strategies.

The Host Range of Fusarium proliferatum in Western Canada.

Fusarium proliferatum is associated with the root rot of many plant species, but knowledge of its impact on western Canadian field crops is limited. This study assessed the host range of this fungus and its effect on plant emergence, plant height, and shoot and root dry weights in repeated greenhouse experiments with wheat, barley, faba beans, peas, lentils, canola, lupine, and soybeans. Infection was confirmed via PCR, and principal component analysis determined the utility of different parameters in assessing host responses. All crops were at least partly susceptible, developing mild to severe disease at the seedling and adult stages, and showing significant reductions in growth. In general, the barley and wheat demonstrated higher tolerances to infection, followed by the faba bean and the pea. The soybean, canola, lupine, and lentil were most susceptible. The canola and the soybean were particularly vulnerable to F. proliferatum at the pre-emergence stage, while infection greatly reduced the lentil's biomass. Reductions in the barley's emergence and other growth parameters, however, occurred only under a high inoculum concentration. Variability in root rot severity among cultivars of the same crop indicated some diversity in host reactions within species. Nonetheless, the absence of fully-resistant crops may pose challenges in managing F. proliferatum in western Canadian cropping systems.

PEGylated Recombinant Aplysia punctata Ink Toxin Depletes Arginine and Lysine and Inhibits the Growth of Tumor Xenografts.

In recent years, a novel treatment method for cancer has emerged, which is based on the starvation of tumors of amino acids like arginine. The deprivation of arginine in serum is based on enzymatic degradation and can be realized by arginine deaminases like the l-amino acid oxidase found in the ink toxin of the sea hare Aplysia punctata. Previously isolated from the ink, the l-amino acid oxidase was described to oxidate the essential amino acids l-lysine and l-arginine to their corresponding deaminated alpha-keto acids. Here, we present the recombinant production and functionalization of the amino acid oxidase Aplysia punctata ink toxin (APIT). PEGylated APIT (APIT-PEG) increased the blood circulation time. APIT-PEG treatment of patient-derived xenografted mice shows a significant dose-dependent reduction of tumor growth over time mediated by amino acid starvation of the tumor. Treatment of mice with APIT-PEG, which led to deprivation of arginine, was well tolerated.

Assessment of induced allelopathy in crop-weed co-culture with rye-pigweed model

This study evaluates induced allelopathy in a rye-pigweed model driven by rye’s (Secale cereale L.) allelopathic potential as a cover crop and pigweed’s (Amaranthus retroflexus L.) notoriety as a weed. The response of rye towards pigweed’s presence in terms of benzoxazinoids (BXs) provides valuable insight into induced allelopathy for crop improvement. In the 2 week plant stage, pigweed experiences a significant reduction in growth in rye’s presence, implying allelopathic effects. Rye exhibits increased seedling length and BXs upsurge in response to pigweed presence. These trends persist in the 4 week plant stage, emphasizing robust allelopathic effects and the importance of different co-culture arrangements. Germination experiments show rye’s ability to germinate in the presence of pigweed, while pigweed exhibits reduced germination with rye. High-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis identifies allelopathic compounds (BXs), 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) in rye. Rye significantly increases BX production in response to pigweed, age-dependently. Furthermore, pigweed plants are screened for possible BX uptake from the rhizosphere. Results suggest that allelopathy in rye-pigweed co-cultures is influenced by seed timing, and age-dependent dynamics of plants’ allelopathic compounds, providing a foundation for further investigations into chemical and ecological processes in crop-weed interactions.

Preclinical Testing of Chronic ICA-1S Exposure: A Potent Protein Kinase C-ι Inhibitor as a Potential Carcinoma Therapeutic

Protein kinase C-iota (PKC-ι) is an oncogene overexpressed in many cancer cells including prostate, breast, ovarian, melanoma, and glioma cells. Previous in vitro studies have shown that 5-amino-1-((1R,2S,3R,4R)-2-3-dihydroxy-4-(hydroxymethyl)cyclopentyl)-1H-imidazole-4-carboxamide (ICA-1S), a PKC-ι-specific inhibitor, has low toxicity in both acute and sub-acute mouse model toxicological testing and is an effective therapeutic against several cancer cell lines showing significant reductions in tumor growth when treating athymic nude mice with xenografted carcinoma cell lines. To further assess ICA-1S as a possible therapeutic agent, chronic mouse model toxicological testing was performed in vivo to provide inferences concerning the long-term effects and possible health hazards from repeated exposure over a substantial part of the animal’s lifespan. Subjects survived well after 30, 60, and 90 days of doses ranging from 50 mg/kg to 100 mg/kg. Heart, liver, kidney, and brain tissues were then analyzed for accumulations of ICA-1S including the measured assessment of aspartate transaminase (AST), alkaline phosphatase (ALK-P), gamma-glutamyl transferase (GGT), troponin, and C-reactive protein (CRP) serum levels to assess organ function. Predictive in vitro/in silico methods were used to predict compound-induced direct hepatocyte toxicity or renal proximal tubular cell (PTC) toxicity in humans based on the high-content imaging (HCI) of compound-treated cells in combination with phenotypic profiling. In conclusion, ICA-1S shows low toxicity in both acute and chronic toxicology studies, and shows promise as a potential therapeutic.

Water‐in‐Polymer Salt Electrolyte for Long‐Life Rechargeable Aqueous Zinc‐Lignin Battery

Zinc metal batteries (ZnBs) are poised as the next‐generation energy storage solution, complementing lithium‐ion batteries, thanks to their cost‐effectiveness and safety advantages. These benefits originate from the abundance of zinc and its compatibility with non‐flammable aqueous electrolytes. However, the inherent instability of zinc in aqueous environments, manifested through hydrogen evolution reactions (HER) and dendritic growth, has hindered commercialization due to poor cycling stability. Enter potassium polyacrylate (PAAK)‐based water‐in‐polymer salt electrolyte (WiPSE), a novel variant of water‐in‐salt electrolytes (WiSE), designed to mitigate side reactions associated with water redox processes, thereby enhancing the cyclic stability of ZnBs. In this study, WiPSE was employed in ZnBs featuring lignin and carbon composites as cathode materials. Our research highlights the crucial function of acrylate groups from WiPSE in stabilizing the ionic flux on the surface of the Zn electrode. This stabilization promotes the parallel deposition of Zn along the (002) plane, resulting in a significant reduction in dendritic growth. Notably, our sustainable Zn‐lignin battery showcases remarkable cyclic stability, retaining 80% of its initial capacity after 8000 cycles at a high current rate (1 A g−1) and maintaining over 75% capacity retention up to 2000 cycles at a low current rate (0.2 A g−1). This study showcases the practical application of WiPSE for the development of low‐cost, dendrite‐free, and scalable ZnBs.

SFlt-1 impairs neurite growth and neuronal differentiation in SH-SY5Y cells and human neurons.

Pre-eclampsia (PE) is a hypertensive disorder of pregnancy which is associated with increased risk of neurodevelopmental disorders in exposed offspring. The pathophysiological mechanisms mediating this relationship are currently unknown, and one potential candidate is the anti-angiogenic factor soluble Fms-like tyrosine kinase 1 (sFlt-1), which is highly elevated in PE. While sFlt-1 can impair angiogenesis via inhibition of VEGFA signalling, it is unclear whether it can directly affect neuronal development independently of its effects on the vasculature. To test this hypothesis, the current study differentiated the human neural progenitor cell (NPC) line ReNcell® VM into a mixed culture of mature neurons and glia, and exposed them to sFlt-1 during development. Outcomes measured were neurite growth, cytotoxicity, mRNA expression of nestin, MBP, GFAP, and βIII-tubulin, and neurosphere differentiation. sFlt-1 induced a significant reduction in neurite growth and this effect was timing- and dose-dependent up to 100 ng/ml, with no effect on cytotoxicity. sFlt-1 (100 ng/ml) also reduced βIII-tubulin mRNA and neuronal differentiation of neurospheres. Undifferentiated NPCs and mature neurons/glia expressed VEGFA and VEGFR-2, required for endogenous autocrine and paracrine VEGFA signalling, while sFlt-1 treatment prevented the neurogenic effects of exogenous VEGFA. Overall, these data provide the first experimental evidence for a direct effect of sFlt-1 on neurite growth and neuronal differentiation in human neurons through inhibition of VEGFA signalling, clarifying our understanding of the potential role of sFlt-1 as a mechanism by which PE can affect neuronal development.

Electron-transferring flavoprotein and its dehydrogenase contributed to growth development and virulence in Beauveria bassiana

Electron-transferring flavoprotein (Etf) and its dehydrogenase (Etfdh) are integral components of the electron transport chain in mitochondria. In this study, we characterize two putative etf genes (Bbetfa and Bbetfb) and their dehydrogenase gene Bbetfdh in the entomopathogenic fungus Beauveria bassiana. Individual deletion of these genes caused a significant reduction in vegetative growth, conidiation, and delayed conidial germination. Lack of these genes also led to abnormal metabolism of fatty acid and increasing lipid body accumulation. Furthermore, the virulence of Bbetfs and Bbetfdh deletion mutants was severely impaired due to decreasing infection structure formation. Additionally, all deletion strains showed reduced ATP synthesis compared to the wild-type strain. Taken together, Bbetfa and Bbetfb, along with Bbetfdh, play principal roles in fungal vegetative growth, conidiation, conidial germination, and pathogenicity of B. bassiana due to their essential functions in fatty acid metabolism.

Anti-candidiasis functional material for women’s cotton undergarments

The escalating incidence of Candida spp. infections among individuals with compromised immune systems is attributed to various factors, including broad-spectrum antibiotic usage, common health issues, and inadequate undergarments, requiring novel preventive measures. While the pathogenic mechanisms of Candida spp. infections remain incompletely understood, their virulence attributes and opportunistic nature challenge host defenses. In response, this research study introduces an innovative nanobiotechnological approach employing L-cysteine to develop nontoxic anti- Candida spp. textile materials. Cotton, an ideal material for women’s underwear, was functionalized with L-cysteine through an exhaustion procedure following activation with 2,2,6,6-tetramethylpiperidinyl-1-oxy free radical. The results demonstrated increased energy dispersive X-ray peaks corresponding to sulfur atoms in the functionalized cotton fabric, confirming that L-cysteine remained attached to the cotton surface even after washing cycles. Moreover, the cotton containing L-cysteine displayed morphology and mechanical properties similar to the nonfunctionalized cotton, indicating that the incorporation of L-cysteine did not impact the cotton properties. In addition, cotton functionalized with L-cysteine exhibited a significant reduction in yeast growth – 87.04 ± 1.90% for Candida albicans and 65.28 ± 3.03% for Candida parapsilosis – highlighting its potential as a class I medical device, particularly for preventing candidiasis in women’s medical underwear.

Gastric Inhibitory Polypeptide Receptor (GIPR) Overexpression Reduces the Tumorigenic Potential of Retinoblastoma Cells.

Retinoblastoma (RB) is the most common malignant intraocular tumor in early childhood. Gene expression profiling revealed that the gastric inhibitory polypeptide receptor (GIPR) is upregulated following trefoil factor family peptide 1 (TFF1) overexpression in RB cells. In the study presented, we found this G protein-coupled transmembrane receptor to be co-expressed with TFF1, a new diagnostic and prognostic RB biomarker for advanced subtype 2 RBs. Functional analyses in two RB cell lines revealed a significant reduction in cell viability and growth and a concomitant increase in apoptosis following stable, lentiviral GIPR overexpression, matching the effects seen after TFF1 overexpression. In chicken chorioallantoic membrane (CAM) assays, GIPR-overexpressing RB cells developed significantly smaller CAM tumors. The effect of GIPR overexpression in RB cells was reversed by the GIPR inhibitor MK0893. The administration of recombinant TFF1 did not augment GIPR overexpression effects, suggesting that GIPR does not serve as a TFF1 receptor. Investigations of potential GIPR up- and downstream mediators suggest the involvement of miR-542-5p and p53 in GIPR signaling. Our results indicate a tumor suppressor role of GIPR in RB, suggesting its pathway as a new potential target for future retinoblastoma therapy.

Life cycle exposure to titanium dioxide nanoparticles (TiO2-NPs) induces filial toxicity and population decline in the nematode Caenorhabditis elegans.

Titanium dioxide nanoparticle (TiO2-NP) exposure has raised significant concern due to their potential toxicity and adverse ecological impacts. Despite their ubiquitous presence in various environmental compartments, the long-term consequences of TiO2-NPs remain poorly understood. In this study, we combined data of in vivo toxicity and modeling to investigate the potential negative impacts of TiO2-NP exposure. We employed the nematode Caenorhabditis elegans, an environmental organism, to conduct a full life cycle TiO2-NP toxicity assays. Moreover, to assess the potential impact of TiO2-NP toxicity on population dynamics, we applied a stage-constructed matrix population model (MPM). Results showed that TiO2-NPs caused significant reductions in reproduction, survival, and growth of parental C. elegans (P0) at the examined concentrations. Moreover, these toxic effects were even more pronounced in the subsequent generation (F1) when exposed to TiO2-NPs. Furthermore, parental TiO2-NP exposure resulted in significant toxicity in non-exposed C. elegans progeny (TiO2-NPs free), adversely affecting their reproduction, survival, and growth. MPM analysis revealed decreased transition probabilities of surviving (Pi), growth (Gi), and fertility (Fi) in scenarios with TiO2-NP exposure. Additionally, the population growth rate (λmax) was found to be less than 1 in both P0 and F1, indicating a declining population trend after successive generations. Sensitivity analysis pinpointed L1 larvae as the most vulnerable stage, significantly contributing to the observed population decline in both P0 and F1 generations under TiO2-NP exposure. Our findings provide insight into the potential risk of an environmental organism like nematode by life cycle exposure to TiO2-NPs.

Predicted impact, establishment and distribution of Heikertingerella sp. (Coleoptera, Chrysomelidae), recently released for the biological control of Tecoma stans in South Africa

Abstract Biological control practitioners are required to demonstrate that candidate agents are not only safe for release, but will establish widely in their new range with a significant impact on the target weed. We conducted this study in quarantine to provide insight into the impact and distribution of the root‐feeding flea beetle Heikertingerella sp. (Chrysomelidae), released in early 2023 against the invasive tree Tecoma stans (L.) (Bignoniaceae) in South Africa. We studied the effects of low and high beetle densities on plant growth and biomass, and F1 progeny production by the beetle. There were significant reductions in plant growth and biomass accumulation in the beetle‐exposed plants, relative to the controls. P1 adults damaged significantly more leaflets, with significantly higher F1 progeny production, at high beetle densities. The MaxEnt model predictions suggested that most of South Africa is climatically highly suitable for Heikertingerella sp., particularly along the southern and eastern coasts where the weed is most prevalent. Only the inland regions of the Northern Cape Province, depicting the driest and hottest part of the country where the weed does not occur, were predicted to be unsuitable for Heikertingerella sp. The beetle's thermal physiology, as determined by its critical thermal minimum and maximum temperatures and lower and upper lethal temperatures (LT50), suggests tolerance to temperature extremes in at least four of the eight provinces that fall within the range of T. stans in South Africa. Our results further justify the release of Heikertingerella sp. in areas predicted as suitable in South Africa.

Chitin-mediated blockade of chitinase-like proteins reduces tumor immunosuppression, inhibits lymphatic metastasis and enhances anti-PD-1 efficacy in complementary TNBC models

BackgroundChitinase-like proteins (CLPs) play a key role in immunosuppression under inflammatory conditions such as cancer. CLPs are enzymatically inactive and become neutralized upon binding of their natural ligand chitin, potentially reducing CLP-driven immunosuppression. We investigated the efficacy of chitin treatment in the context of triple-negative breast cancer (TNBC) using complementary mouse models. We also evaluated the immunomodulatory influence of chitin on immune checkpoint blockade (ICB) and compared its efficacy as general CLP blocker with blockade of a single CLP, i.e. chitinase 3-like 1 (CHI3L1).MethodsFemale BALB/c mice were intraductally injected with luciferase-expressing 4T1 or 66cl4 cells and systemically treated with chitin in combination with or without anti-programmed death (PD)-1 ICB. For single CLP blockade, tumor-bearing mice were treated with anti-CHI3L1 antibodies. Metastatic progression was monitored through bioluminescence imaging. Immune cell changes in primary tumors and lymphoid organs (i.e. axillary lymph nodes and spleen) were investigated through flow cytometry, immunohistochemistry, cytokine profiling and RNA-sequencing. CHI3L1-stimulated RAW264.7 macrophages were subjected to 2D lymphatic endothelial cell adhesion and 3D lymphatic integration in vitro assays for studying macrophage-mediated lymphatic remodeling.ResultsChitin significantly reduced primary tumor progression in the 4T1-based model by decreasing the high production of CLPs that originate from tumor-associated neutrophils (TANs) and Stat3 signaling, prominently affecting the CHI3L1 and CHI3L3 primary tumor levels. It reduced immunosuppressive cell types and increased anti-tumorigenic T-cells in primary tumors as well as axillary lymph nodes. Chitin also significantly reduced CHI3L3 primary tumor levels and immunosuppression in the 66cl4-based model. Compared to anti-CHI3L1, chitin enhanced primary tumor growth reduction and anti-tumorigenicity. Both treatments equally inhibited lymphatic adhesion and integration of macrophages, thereby hampering lymphatic tumor cell spreading. Upon ICB combination therapy, chitin alleviated anti-PD-1 resistance in both TNBC models, providing a significant add-on reduction in primary tumor and lung metastatic growth compared to chitin monotherapy. These add-on effects occurred through additional increase in CD8α+ T-cell infiltration and activation in primary tumor and lymphoid organs.ConclusionsChitin, as a general CLP blocker, reduces CLP production, enhances anti-tumor immunity as well as ICB responses, supporting its potential clinical relevance in immunosuppressed TNBC patients.

Abstract LB021: BAU-243: A novel BCL-2 inhibitor inducing autophagic cell death in glioblastoma, unveiled through multistep virtual screening, comprehensive in vitro and in vivo animal model evaluation

Abstract The excessive expression of antiapoptotic members in the B-cell leukemia/lymphoma-2 (BCL-2) family proteins emerges as a noteworthy oncogenic target in cancer cells. Employing a multistep virtual screening and filtering approach that integrates structure and ligand-based drug design, we aimed to identify novel and potent BCL-2 inhibitors from a sizable small molecule database, comprising over 210,000 compounds. Subsequently, seven selected molecules underwent rigorous biological activity tests in human cancer cell lines and Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) assays. Four of these compounds exhibited notable inhibitory effects on cancer cell proliferation and led to an increase in apoptotic cell fractions. Among the identified compounds, BAU-243 displayed a substantial affinity for Bcl-2, demonstrating efficacy in reducing glioblastoma (GBM) cell proliferation, including cancer-initiating cells. Notably, in contrast to the selective Bcl-2 inhibitor ABT-199, BAU-243 induced autophagic cell death in GBM cells. In vivo investigations using orthotopic brain tumor models revealed a significant reduction in tumor growth with BAU-243 compared to both the vehicle group and animals treated with ABT-199. Computational modeling simulations, in concordance with in vitro findings, proposed that BAU-243 activates autophagic cell death by disrupting the Beclin 1:Bcl-2 complex. This positions BAU-243 as a promising small molecule for the treatment of GBM. Citation Format: Seyma Calis, Berna Dogan, Asuman Celebi, Ozlem Yapicier, Turker Kilic, Eda Tahir Turanli, Timucin Avsar, Serdar Durdagi. BAU-243: A novel BCL-2 inhibitor inducing autophagic cell death in glioblastoma, unveiled through multistep virtual screening, comprehensive in vitro and in vivo animal model evaluation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB021.

IL7 in combination with radiotherapy stimulates a memory T-cell response to improve outcomes in HNSCC models

Clinically approved head and neck squamous cell carcinoma (HNSCC) immunotherapies manipulate the immune checkpoint blockade (ICB) axis but have had limited success outside of recurrent/metastatic disease. Interleukin-7 (IL7) has been shown to be essential for effector T-cell survival, activation, and proliferation. Here, we show that IL7 in combination with radiotherapy (RT) is effective in activating CD8 + T-cells for reducing tumor growth. Our studies were conducted using both human papillomavirus related and unrelated orthotopic HNSCC murine models. Immune populations from the tumor, draining lymph nodes, and blood were compared between treatment groups and controls using flow cytometry, proteomics, immunofluorescence staining, and RNA sequencing. Treatment with RT and IL7 (RT + IL7) resulted in significant tumor growth reduction, high CD8 T-cell tumor infiltration, and increased proliferation of T-cell progenitors in the bone marrow. IL7 also expanded a memory-like subpopulation of CD8 T-cells. These results indicate that IL7 in combination with RT can serve as an effective immunotherapy strategy outside of the conventional ICB axis to drive the antitumor activity of CD8 T-cells.

Dynamic Proteomic Changes in Tumor and Immune Organs Reveal Systemic Immune Response to Tumor Development

In orthotopic mouse tumor models, tumor progression is a complex process, involving interactions among tumor cells, host cell-derived stromal cells, and immune cells. Much attention has been focused on the tumor and its tumor microenvironment, while the host’s macroenvironment including immune organs in response to tumorigenesis is poorly understood. Here, we report a temporal proteomic analysis on a subcutaneous tumor and three immune organs (LN, MLN, and spleen) collected on Days 0, 3, 7, 10, 14, and 21 after inoculation of mouse forestomach cancer cells in a syngeneic mouse model. Bioinformatics analysis identified key biological processes during distinct tumor development phases, including an initial acute immune response, the attack by the host immune system, followed by the adaptive immune activation, and the build-up of extracellular matrix. Proteomic changes in LN and spleen largely recapitulated the dynamics of the immune response in the tumor, consistent with an acute defense response on D3, adaptive immune response on D10, and immune evasion by D21. In contrast, the immune response in MLN showed a gradual and sustained activation, suggesting a delayed response from a distal immune organ. Combined analyses of tumors and host immune organs allowed the identification of potential therapeutic targets. A proof-of-concept experiment demonstrated that significant growth reduction can be achieved by dual inhibition of MEK and DDR2. Together, our temporal proteomic dataset of tumors and immune organs provides a useful resource for understanding the interaction between tumors and the immune system and has the potential for identifying new therapeutic targets for cancer treatment.

Improving osseointegration and antimicrobial properties of titanium implants with black phosphorus nanosheets-hydroxyapatite composite coatings for vascularized bone regeneration.

For decades, titanium implants have shown impressive advantages in bone repair. However, the preparation of implants with excellent antimicrobial properties as well as better osseointegration ability remains difficult for clinical application. In this study, black phosphorus nanosheets (BPNSs) were doped into hydroxyapatite (HA) coatings using electrophoretic deposition. The coatings' surface morphology, roughness, water contact angle, photothermal properties, and antibacterial properties were investigated. The BP/HA coating exhibited a surface roughness of 59.1 nm, providing an ideal substrate for cell attachment and growth. The water contact angle on the BP/HA coating was measured to be approximately 8.55°, indicating its hydrophilic nature. The BPNSs demonstrated efficient photothermal conversion, with a temperature increase of 42.2°C under laser irradiation. The BP/HA composite coating exhibited a significant reduction in bacterial growth, with inhibition rates of 95.6% and 96.1% against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility of the composite coating was evaluated by cell adhesion, CCK8 and AM/PI staining; the effect of the composite coating in promoting angiogenesis was assessed by scratch assay, transwell assay, and protein blotting; and the osteoinductivity of the composite coating was evaluated by alkaline phosphatase assay, alizarin red staining, and Western blot. The results showed that the BP/HA composite coating exhibited superior performance in promoting biological functions such as cell proliferation and adhesion, antibacterial activity, osteogenic differentiation, and angiogenesis, and had potential applications in vascularized bone regeneration.

Abstract 3925: Cancer-associated fibroblast-derived Dickkopf-1 impairs anti-tumor immunity in breast cancer by suppressing NK cell-mediated cytotoxicity

Abstract Despite early diagnosis, 10-20% of breast cancer patients experience metastatic disease within 5-10 years. While it is established that breast cancer cells have the capacity to evade immune responses, the mechanisms driving this evasion remain elusive. Therefore, finding ways to enhance anti-tumor immunity is crucial to improve patient outcomes. Dickkopf-1 (DKK1) is a Wnt inhibitor whose levels correlate with poor prognosis and decreased immune infiltration in various cancers. In this study, we used mice orthotopically injected with the PyMT, EO771, and 4T1 breast cancer lines. In all models, we found elevated DKK1 serum levels, and its neutralization with an αDKK1 Ab resulted in a significant reduction in primary tumor growth but also in metastatic dissemination. To identify the source of DKK1, we examined its expression in the tumor. DKK1 was detected in stromal cells with a fibroblast-like morphology but not in cancer cells or immune infiltrates. Co-staining confirmed colocalization between DKK1 and the CAF marker αSMA. To address the role of CAF-derived DKK1, we specifically deleted DKK1 in CAFs by generating FSP1CreDkk1fl/fl and αSMACreERT2Dkk1fl/fl mice. Both models showed a significant reduction in primary tumor growth while maintaining comparable serum DKK1 levels, indicating locally produced DKK1 supports tumor growth. To understand how DKK1 promotes tumor progression, we conducted bulk RNAseq of tumor cells isolated from IgG or αDKK1 treated mice. While no changes related to cell viability or cell cycle were observed, immune response-related genes were upregulated in αDKK1-treated cells. In support of this, αDKK1 did not reduce tumor growth in NSG immune-compromised mice. To pinpoint the immune cell targeted by DKK1, we depleted T, NK cells, or macrophages in WT tumor-bearing mice treated with αDKK1. Remarkably, only NK cell depletion negated αDKK1 anti-tumor effects. In vitro assays further demonstrated that rDKK1 or the presence of CAFs reduced NK cell cytotoxicity against tumor cells while αDKK1 restored it. To assess whether DKK1 levels correlated with tumor progression and immune suppression in breast cancer patients, we analyzed DKK1 serum levels and circulating NK cells at the diagnosis of metastatic bone disease and 15-18 months after standard care. DKK1 levels were significantly elevated in patients with progressive bone disease compared to those with stable disease. Importantly, NK cells from the progressive disease cohort had reduced perforin and granzyme B expression at the follow-up visit compared to baseline, indicating reduced cytotoxicity. Furthermore, rDKK1 reduced perforin in NK cells from healthy donors. In sum, our data show DKK1 is an important regulator of breast cancer progression, and we report for the first time DKK1 directly impairs NK cell cytotoxicity, creating an immune suppressive environment resistant to treatment. Citation Format: Seunghyun Lee, Biancamaria Ricci, Roberta Faccio. Cancer-associated fibroblast-derived Dickkopf-1 impairs anti-tumor immunity in breast cancer by suppressing NK cell-mediated cytotoxicity [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 3925.