Mouse Breast Cancer Research Articles

Cucurbitacin-E; Curvularia lunata Secondary Metabolite as a BRCA 1 and 2 Regulator in Mice Associated Breast Cancer

Background: Cucurbitacin-induced apoptosis and inhibition of cell growth can render several cancers ineffective. The microbial transformation of cucurbitacin-E-glucoside to cucurbitacin- E was carried out by Curvularia lunata (NRRL 2178). Moreover, in vitro anticancer activity against the MCF-7 cell line as well as in vivo anticancer activity against dimethylbenz (a) anthracene (DMBA)-induced breast cancer in mice using cucurbitacin-E was evaluated. Methods: The cucurbitacin-E-glucoside was biotransformed by Curvularia lunata to cucurbitacin- E, and the isolated compound was tested in vitro against the MCF-7 cell line, and its IC50 was calculated. LD50 of cucurbitacin-E was estimated in mice, and its protective activity against DMBA-induced cancer in mice was studied. Breast cancer induction was done by a single-dose subcutaneous administration of DMBA (50 mg). Plasma ALT, AST, ALP, and LDH, as well as GSH, SOD, GPx, MDA, TNF-α, IL-6, and tumor suppressor P53 assays, were used to assess cucurbitacin- E's capacity to protect the liver and breast against DMBA-induced toxicity. Moreover, by assessing the gene expression of tumor suppressor genes (BRCA 1 and 2) and conducting histopathological analysis, the suppressive effect of cucurbitacin-E was examined. Results: The IC50 value of cucurbitacin-E against MCF-7 cell lines equals 72.15 ± 0.64 μg/ml. LD50 of cucurbitacin-E given orally in adult mice is equal to 1200 mg/kg b.w. The levels of plasma ALT, AST, ALP, and LDH were decreased significantly in DMBA-treated mice when administered with cucurbitacin-E at 1/50 LD50 (24 mg/kg/b.w.) and 1/20 LD50 (60 mg/kg/b.w.). In breast tissue, the levels of GSH, SOD, GPx, and P53 were significantly increased, as were decreased levels of TNF-α, IL-6, P53, and MDA. Conversely, there was a downregulation in the mRNA expression levels of BRCA1 and BRCA2. The histopathological analysis revealed that cucurbitacin-E management improved the tissue architecture of breast tumors. Conclusions: These findings demonstrate the ability of cucurbitacin-E to inhibit cancer cells in the rat breast by controlling oxidative stress and inflammatory biomarkers, as well as downregulating the mRNA expression levels of BRCA1 and BRCA2.

Synthesis, pharmacological evaluation, and modeling of novel quaternary ammonium salts derived from β-carboline containing an imidazole moiety as angiogenesis inhibitors

In this study, a series of novel β-carboline condensed imidazolium derivatives (7a-7y) were designed and synthesized by incorporating imidazolium salt structures into β-carboline. The cytotoxicity of compounds 7a-7y was evaluated in various cancer cell lines, including lung cancer (A549), gastric cancer (BGC-823), mouse colon cancer (CT-26), liver cancer (Bel-7402), and breast cancer (MCF-7), using the MTT assay. Most compounds exhibited significant activity against one or more of the cancer cell lines. Notably, compounds 7 g, 7o, 7r, 7 s, 7u, 7v, 7x, and 7w showed the highest cytotoxic activity (IC50 < 2 μM) in the tested tumor cell lines. Compound 7x demonstrated cytotoxic activities of 1.3 ± 0.3 μM (for BGC-823), 2.4 ± 0.4 μM (against A549), 7.8 ± 0.9 μM (for Bel-7402), and 9.8 ± 1.4 μM (against CT-26). The chick chorioallantoic membrane assay revealed significant anti-angiogenic potential of compound 7x. Molecular imprinting studies suggested the anti-angiogenic effect of compound 7x might be attributed to inhibition of VEGFR2 kinase. Molecular docking and molecular dynamics further indicate that its activity may be primarily associated with the potential inhibition of VEGFR2. Our research outcomes have provided valuable lead compounds for the development of novel antitumor drugs and have offered beneficial insights for subsequent drug design and optimization.

Synthesis of a novel water-soluble pyridine dicarboxylate and its application in fluorescence cell imaging

Abstract A novel water-soluble substituted pyridine dicarboxylate containing a quaternary ammonium ion with potential applications in fluorescence cell imaging was synthesized and characterized. Remarkably, this compound exhibited water solubility in the absence of additional solubilizers, enabling direct dissolution in phosphate-buffered saline for cell studies. No obvious cytotoxicity was observed in 4T1 cells (mouse breast cancer cells) within the concentration range of 0.2–25 μmol L−1, with a cell survival rate above 89%. Furthermore, the compound exhibited a maximum two-photon absorption cross-section of 86 GM at an excitation wavelength of 780 nm, demonstrating high cell permeability, effective distribution in the cytoplasm, and preferential targeting of organelles. Single- and two-photon fluorescence imaging of cells revealed a distinctive blue emission and strong bright green emission, respectively. The newly synthesized substituted pyridine dicarboxylate exhibited low cytotoxicity and strong fluorescence imaging properties, demonstrating its potential in cell imaging applications.

Flurbiprofen axetil is involved in basal-like breast cancer metastasis via suppressing the MEK/ERK signaling pathway.

Flurbiprofen axetil is commonly utilized in clinical practice as one of the nonsteroidal anti-inflammatory drugs (NSAIDs) and is included in multimodal analgesia regimens postbreast cancer surgery. Numerous NSAIDs have been studied for their potential to both promote and inhibit cancer. Given the variability in their effects on tumors, further investigation into the specific role of flurbiprofen axetil is warranted. Therefore, the primary objective of this study was to assess the impact of flurbiprofen axetil on basal-like breast cancer (BLBC) metastasis and elucidate the underlying molecular mechanisms involved. The BLBC metastasis mouse model was established by caudal vein injection of tumor cells. The lung metastasis of breast cancer in mice and the effect of flurbiprofen axetil were assessed by in vivo bioluminescence imaging, hematoxylin and eosin staining and immunohistochemistry. In vitro, the results of flurbiprofen axetil on the proliferation, migration, and invasion of MDA-MB-231 human breast cancer cells and BT-549 human breast cancer cells were assessed by colony formation assay and transwell assay. The effects of flurbiprofen axetil on several tumor metastasis-related signaling pathway proteins were examined by western blot, and the reversal extent of the flurbiprofen axetil effect by Ro 67-7476 (ERK phosphorylation agonist) was detected by transwell assay. The results showed that flurbiprofen axetil significantly inhibited BLBC lung metastasis in mice. Flurbiprofen axetil similarly inhibited breast cancer cell migration and invasion in vitro but did not affect their proliferation. Mechanistic investigations have revealed that flurbiprofen axetil exerts a noteworthy inhibitory influence on the MEK/ERK pathway while exhibiting no significant alteration in the expression of other pathway proteins intricately associated with epithelial-mesenchymal transition. In conclusion, the inhibitory effect of flurbiprofen axetil on BLBC metastasis is characterized by its selectivity in targeting the MEK/ERK signaling pathway rather than exerting a broad impact on the global signaling pathway.

Construction of Lactobacillus casei-loaded Water-in-oil High Internal Phase Emulsion and its Study on Anti-breast Cancer Properties

Objective: To prepare an oil-in-water high internal phase emulsion containing Lactobacillus casei, and to optimize and characterize the preparation process. To explore the therapeutic effect of the probiotic-carrying emulsion on in situ breast cancer in mice. Methods: Using corn oil, sodium alginate, polyglycerin ricinoleate and L. casei as raw materials, the high internal phase emulsion containing probiotic oil-in-water was prepared by high-speed homogenization method. The optimal preparation process was obtained through single factor investigation, microstructure characterization, stability investigation and in vitro simulation digestion experiment. Ten female BALB/c mice (SPF grade, 18–20 g) were selected. After the in situ breast cancer model was successfully established, the mice were randomly divided into experimental group and control group, with 5 mice in each group. The mice were administrated with probiotic-loaded emulsion and normal saline respectively, and were administrated with the stomach every other day for 10 days. The change of tumor volume during treatment and tumor mass at the end of treatment were recorded. Results: The optimum process of emulsion was: With the concentration of 5% Polyglycerin ricinolate, 75% aqueous volume, 3000r/min homogenizing speed, 30 s homogenizing time and 2% aqueous sodium alginate concentration, a high internal phase emulsion with a particle size of 9.33 ± 1.74 μm and an appearance of milky paste was prepared. The inclusion rate of probiotics reached 90.97 ± 27.09%. Breast cancer anti-tumor experiment showed that the tumor inhibition rate of the experimental group reached 33.78% compared with the control group. Conclusion: Water-in-oil high internal phase emulsion can effectively protect L. casei and reduce the loss of live probiotic when probiotics pass through the digestive fluid environment. Oral intragastric high internal phase emulsion containing L. casei oil-in-water has a certain therapeutic effect on breast cancer.

Preparation and Formulation of a New Therapeutic Supplement by the Combination of Dendritic Cells and IPI-549 (Eganelisib) for the Treatment of Breast Cancer in BALB/c Mice

: Dendritic cell-based cancer immunotherapy is considered an innovative and promising approach aimed at enhancing the host's immune response to combat tumors. Additionally, IPI-549 has been identified as a first-line therapeutic option for breast cancer treatment. The objective of this research was to develop and formulate a novel therapeutic supplement by combining dendritic cells with IPI-549 (Eganelisib) for breast cancer treatment. The concurrent administration of dendritic cells and IPI-549 (DC-IPI) was utilized to treat mice and elicit immunological responses triggered by vaccination. Tumor regression and overall survival rates were evaluated across five distinct experimental groups. The administration of tumor cell lysate alongside DC-IPI resulted in a significant reduction in tumor growth and a two- to three-fold increase in the survival duration of treated mice. DC-IPI, whether decorated with mannan or not, elicited stronger responses in terms of delayed-type hypersensitivity, lymphocyte proliferation, and CD107a expression. Moreover, our findings demonstrated a reduction in IL-4 production in the supernatants of splenocyte cultures. A significant reduction in BRCA1 mRNA levels was also observed following treatment with DC-IPI. In conclusion, our results suggest that the DC-IPI antigen delivery system exhibited substantial anti-tumor efficacy in a breast cancer mouse model, representing a potential advancement in immunotherapy for human breast cancer.

Polyphyllin II inhibits breast cancer cell proliferation via the PI3K/Akt signaling pathway.

Paridis Rhizoma saponins (PRS) are significant components of Rhizoma Paridis and have inhibitory effects on various tumors, such as bladder, breast, liver and colon cancer. Polyphyllin II (PPII), one of the PRS, has an unclear effect on breast cancer. The present study aimed to explore the effect and mechanism of PPII in breast cancer. A network pharmacology approach was employed to predict the core components and breast cancer‑related targets of PRS. Moreover, a xenograft tumor model was established to determine the anti‑breast cancer effect of PPII in vivo. The viability of MDA‑MB‑231 cells was determined by a Cell Counting Kit‑8 assay. Apoptosis was analyzed using annexin V/PI double staining. Additionally, Transwell and scratch assays were performed to evaluate invasion and migration. The potential mechanism was predicted by Kyoto Encyclopedia of Genes and Genomes enrichment analysis and molecular docking analysis and verified by western blot analysis. The effect of PPII on aerobic glycolysis in breast cancer cells was detected by lactic acid and pyruvate kits and Western blotting of glycolytic rate‑limiting enzymes. Network pharmacology analysis revealed 26 core targets involved in breast cancer and that PPII was the core active component of PRS. The in vivo studies showed that PPII could inhibit the growth of breast cancer in mice. In vitro experiments confirmed that PPII induced cancer cell apoptosis and inhibited invasion and migration. Furthermore, PPII was capable of suppressing the expression of key proteins in the PI3K/Akt signaling pathway, reducing the generation of aerobic glycolytic products, and diminishing the protein expression levels of hexokinase 2 and pyruvate kinase M2. The results indicated that PPII inhibited aerobic glycolysis in breast cancer cells through the PI3K/Akt signaling pathway, thereby inhibiting breast cancer growth.

A size-switchable nanocluster remodels the immunosuppressive microenvironment of tumor and tumor-draining lymph nodes for improved cancer immunotherapy

Remodeling the immunosuppressive tumor microenvironment (TME) by immunomodulators has been well studied in the past years. However, strategies that enable concurrent modulation of both the immunosuppressive TME and tumor-draining lymph nodes (TDLNs) are still in the infancy. Here, we report a pH-sensitive size-switchable nanocluster, SPN-R848, to achieve simultaneous accumulation in tumor and TDLNs for immune activation. SPN-R848 with original size around 150 nm was formed by self-assembly of resiquimod (R848)-conjugated polyamidoamine (PAMAM) derivative, which could disintegrate into its small constituents (～ 8 nm) upon exposure to tumor acidity. The size reduction not only enhanced their accumulation and perfusion in the primary tumor, but promoted their transport and distribution in TDLNs. Accordingly, SPN-R848 remarkably remodeled the immunosuppressive TME by polarizing M2 to M1 macrophages and activated dendritic cells (DCs) in TDLNs, which synergistically facilitated the production and stimulation of cytotoxic T cells, and inhibited tumor growth in breast cancer and melanoma mouse models. Our study suggests that co-activation of immune microenvironments in both tumor and TDLNs may represent a promising direction to elicit strong antitumor immunity.

Mesoporous Polydopamine Nanotherapeutics for MRI-Guided Cancer Photothermal and Anti-Inflammatory Therapy.

As a burgeoning cancer treatment modality, photothermal therapy (PTT) has shown robust anti-tumor effects. However, it still faces numerous challenges, such as triggering an inflammatory response and potentially increasing the risk of cancer recurrence. To address these concerns, integration of PTT with anti-inflammatory therapies presents a promising approach to enhance the efficacy of cancer treatment and meanwhile reduce the risk of recurrence. In this study, Gd3+ was first chelated with dopamine to create Gd-DA chelates, and then the mesoporous dopamine nanoparticles MX@Arg-Gd-MPDA (MAGM NPs) were synthesized by combining arginine (Arg) and the anti-inflammatory medication meloxicam (MX). The photothermal properties of MAGM NPs were then defined and examined; the in vivo MRI imaging effect, as well as MAGM NPs' anti-cancer and anti-inflammatory efficiency, were tested in a mouse model of breast cancer. The incorporation of Arg doping into MAGM NPs was intended to boost its photothermal conversion efficiency and reactive oxygen species (ROS) scavenging ability. Additionally, synergizing with the anti-inflammatory agent meloxicam (MX) within the nanoparticles aimed to enhance the anti-inflammatory effect following photothermal therapy. Furthermore, gadolinium ions (Gd3+) were chelated into the nanostructure to enable precise T1-T2 dual-mode magnetic resonance imaging (MRI) of the intratumor accumulation profile. This imaging capability was leveraged to guide the implementation of photothermal therapy. Animal experiments demonstrated that MAGM NPs exerted a notable anticancer effect in a 4T1 breast cancer mouse model, under the precise guidance of MRI.

288 (PB276): Ivermectin enhances the efficacy of modulated electro-hyperthermia in a triple-negative breast cancer mouse model

288 (PB276): Ivermectin enhances the efficacy of modulated electro-hyperthermia in a triple-negative breast cancer mouse model

Hypoxia-induced TIMAP upregulation in endothelial cells and TIMAP-dependent tumor angiogenesis.

TGFβ-inhibited membrane associated protein (TIMAP), the endothelial cell-predominant protein phosphatase 1β regulatory subunit also known as PPP1R16B, promotes in vitro endothelial cell proliferation and angiogenic sprouting. TIMAP was first identified as a target of TGF-β1-mediated repression, but the molecular pathways regulating its expression in endothelial cells are not well-defined. This study examined the role of bone morphogenetic factor 9 (BMP9), hypoxia, and angiogenic growth factors in the regulation of TIMAP expression and determined whether TIMAP plays a role in tumor angiogenesis and growth in vivo. BMP9, which potently activated the SMAD1/5/8 pathway in endothelial cells, significantly reduced TIMAP mRNA and protein expression. Conversely, hypoxia and the prolyl hydroxylase inhibitor Roxadustat raised TIMAP mRNA and protein levels by inhibiting the SMAD1/5/8 pathway. Angiogenic growth factors, including VEGFA and IGF-I, raised endothelial TIMAP levels partly by attenuating SMAD1/5/8 pathway activation, but also through SMAD1/5/8-independent mechanisms. Cultured breast cancer E0771 cells released mediators that raised TIMAP expression in endothelial cells, effects that were inhibited by the VEGF inhibitor Sunitinib in conjunction with the IGF-1 inhibitor Picropodophyllin. In the mouse E0771 breast cancer model in vivo, tumor growth and tumor angiogenesis were markedly attenuated in TIMAP deficient, compared with wild-type littermates. These findings indicate that TIMAP plays a critical proangiogenic function during tumor angiogenesis in vivo, likely through hypoxia-driven inhibition of the SMAD1/5/8 pathway and through the elaboration of angiogenic growth factors by tumor cells.NEW & NOTEWORTHY The protein phosphatase 1 regulatory subunit TGFβ-inhibited membrane associated protein (TIMAP), known to activate AKT in endothelial cells (EC), was shown here to be repressed by bone morphogenetic factor 9 (BMP9). Hypoxia and angiogenic growth factors induced TIMAP expression by inhibiting the BMP9 pathway. In a mouse breast cancer model, TIMAP deletion inhibited tumor angiogenesis and tumor growth. Therefore, the proangiogenic functions of TIMAP are induced by hypoxia and angiogenic growth factors.

EDB-FN-targeted probes for near infrared fluorescent imaging and positron emission tomography imaging of breast cancer in mice.

The extra domain B splice variant of fibronectin (EDB-FN), which is overexpressed in several cancers, is an approved diagnostic and therapeutic target of cancers. The aim of this study was to evaluate the EDB-FN-targeting peptide EDBp as a noninvasive imaging modality for molecular imaging of breast cancer in mice. Western blot, flow cytometry and immunofluorescence were used to assess the expression level of EDB-FN and its binding to EDRp in MCF7, SKBR3, 4T1, EMT6, MDA-MB-231 and MDA-MB-453 cells. Establishment MDA-MB-231-luc cells-based subcutaneous tumor model mice or pulmonary metastasis model mice. The EDRp molecular probes to perform fluorescent probes for near-infrared fluorescence (NIRF)·and PET imaging of model mice. Our results demonstrate that EDBp-Cy5 had a strong binding ability to the MDA-MB-231 cells and exhibited specific tumor accumulation in MDA-MB-231 subcutaneous and pulmonary metastasis model mice. Importantly, the EDBp peptide-based radiotracer [18F]-AlF-NOTA-EDBp provided excellent diagnostic value for positron emission tomography (PET) imaging of breast cancer, especially in subcutaneous model mice. The uptake of [18F]-AlF-NOTA-EDBp in subcutaneous tumors (6.53 ± 0.89%, ID/g) was unexpectedly higher than that in the kidney (4.96 ± 0.20, %ID/g). The high tumor uptake of these probes in mice suggests their potential for application in imaging of EDB-FN-positive breast cancer for disease staging of regional and distant metastases.

Considerations for Exploring Nanosecond Pulsed Electric Fields (nsPEFs) for Treatments of Cancer, Benign Skin Diseases, Atrial Fibrillation, and for New Mechanistic Understandings

Pulsed power includes acquiring electrical energy, compressing it, and releasing it in instantaneous bursts that are low in energy but very high in power. When the pulse duration is near the plasma membrane charging time constant, which is the time during which the cell interior is exposed to the applied pulsed electric field, it affects intracellular structures and functions. The technology is called nanosecond Pulsed Electric Fields (nsPEFs), nanosecond electric pulses (nsEP), or Nanopulse Stimulation (NPSTM) according to Pulse Biosciences, Inc., a company taking the technology to the market. Initial studies showed the elimination of tumor cells in vitro by apoptosis, and other regulated cell death mechanisms, elimination of rodent and canine osteosarcoma, and a basal cell carcinoma clinical trial. In the rat liver and mouse breast cancers, tumor-free animals were in situ vaccinated (ISV), preventing the recurrence of the treated cancers. The technology has also focused on treating benign skin diseases, with some advantages over cryoablation. More recently, the same technology called nanosecond pulsed-field ablation (nsPFA) has been used to treat cardiac arrhythmias like Atrial Fabulation (AFib) with catheters in humans. In pre-clinical studies and now in humans, this technology is showing advantages over radiofrequency ablation and cryoablation. On a new mechanistic landscape, nonlethal nsPEFs modulation of electron transport in the plasma membrane and the mitochondria show potential for controlling redox homeostasis and metabolism. Furthermore, different nsPEF waveforms have different effects on cells; waveforms can differ by pulse duration, rise time, electric field, and/or post-pulse features. So, for nsPEFs, there is a lethal side used for ablation as with NPS and nsPFA and a more recently recognized nonlethal side indicating new possibilities to differentially modify cell physiology depending on the different nsPEF waveforms.

Regulating Manganese-Site Electronic Structure via Reconstituting Nitrogen Coordination for Efficient Non-Oxygen-Dependent Sonocatalytic Therapy against Orthotopic Breast Cancer.

Sonocatalytic therapy (SCT) has emerged as a promising noninvasive modality for tumor treatment but is hindered by the insufficient generation of ultrasound-induced reactive oxygen species (ROS) and the hypoxic tumor microenvironments. Herein, we fabricated a carbon nanoframe-confined N-coordinated manganese single-atom sonocatalyst with a five-coordinated structure (MnN5 SA/CNF) using a phthalocyanine-mediated pyrolysis strategy. The precise coordination structure was identified by synchrotron X-ray absorption fine structure analyses. The MnN5 SA/CNF exhibits superior and nonoxygen-dependent sonocatalytic activity owing to the optimized coordination structure and cavitation effect enhanced by defects. Additionally, density functional theory studies reveal that the five-coordination structure downshifts the d-band center of Mn from -0.547 to -0.829 eV and enhances the desorption capacity for oxygen-containing intermediates, thus accelerating the catalytic process. Finally, the as-synthesized MnN5 SA/CNF demonstrates a significantly enhanced antitumor effect through mitochondrial apoptosis in an orthotopic breast cancer mouse model. This work explores the potential of SAzymes-supported biomedical interventions by leveraging enzymatic activity with sonocatalytic properties.

Gastrin-releasing peptide receptor as theranostic target in estrogen-receptor positive breast cancer: A preclinical study of the theranostic pair [55Co]Co- and [177Lu]Lu-DOTA-RM26

BackgroundPatients with advanced metastatic estrogen receptor-positive breast cancer often develop resistance to standard treatments, leading to uncontrolled progression. Thus, innovative therapies are urgently needed. The gastrin-releasing peptide receptor (GRPR) is overexpressed in various cancers, including breast cancer, making it an interesting theranostic target. RM26, a GRPR-targeting antagonist, has demonstrated promising in vivo kinetics in prostate cancer models. This study evaluated the theranostic capabilities of [55Co]Co−/[177Lu]Lu-DOTA-RM26 in vitro in estrogen receptor-positive breast cancer cells and assessed the diagnostic potential of [55Co]Co-DOTA-RM26 in vivo in a breast cancer mouse model. MethodsWe analyzed the binding specificity of [57Co]Co-/[177Lu]Lu-DOTA-RM26 in T47D breast cancer cells, using [57Co]Co-DOTA-RM26 as a surrogate for [55Co]Co-DOTA-RM26. The therapeutic efficacy of increasing [177Lu]Lu-DOTA-RM26 concentrations was determined via viability assay in vitro. Ex vivo biodistribution of [57Co]Co-DOTA-RM26 (17.2 ± 2.7 kBq, 33 ± 5.2 pmol/mouse) was investigated in 12 mice (n= 4/group) with orthotopic breast cancer tumors. The mice were sacrificed at 4 and 24 h post-injection (pi), including a blocking group (20 nmol of unlabeled [Tyr4]-Bombesin) at 4 h pi. For imaging, two tumor-bearing mice underwent [55Co]Co-DOTA-RM26 PET/CT, 4 and 24 h pi (2.8 ± 0.2 MBq, 167.5 ± 0.5 pmol/mouse), with or without GRPR blocking. ResultsIn vitro studies revealed high, specific binding of [57Co]Co-DOTA-RM26 (43 ± 1 % of total added activity per 106 cells (%IA/106)) and [177Lu]Lu-DOTA-RM26 (37 ± 4 %IA/106). The activity was predominantly localized at the cell surface: 71 ± 3 % and 80 ± 6 % for [57Co]Co-DOTA-RM26 and [177Lu]Lu-DOTA-RM26, respectively. [177Lu]Lu-DOTA-RM26 significantly reduced cell viability at all activity concentrations >0.625 MBq/mL (p < 0.0001), with cell viability below 1 % at concentrations ≥5 MBq/mL. Biodistribution data (n = 12) indicated a high, specific tumor uptake of [57Co]Co-DOTA-RM26, surpassing all other tissues significantly at both time points, 3.7 ± 0.6 % of the injected activity per gram (%IA/g) 4 h pi and 0.98 ± 0.05 %IA/g 24 h pi. The kidneys showed the second-highest uptake (2.0 ± 0.1 %IA/g 4 h pi), followed by the pancreas (1.4 ± 0.4 %IA/g 4 h pi). PET/CT imaging with [55Co]Co-DOTA-RM26 supported the biodistribution data and, distinctly visualized the tumor 24 h pi and showed an improved tumor-to-background compared to the earlier time points. Effective GRPR blocking significantly reduced tumor uptake in the PET images 24 h pi. ConclusionThese findings suggest that the theranostic pair [55Co]Co−/[177Lu]Lu-DOTA-RM26 holds significant promise as a theranostic agent for estrogen receptor-positive breast cancer.

Micelle-encapsulated IR783 for enhanced photothermal therapy in mouse breast cancer

BackgroundPhotothermal therapy, an emerging cancer treatment, selectively eliminates lesions using photothermal compounds that convert light into heat. IR783, a near-infrared fluorescent heptamethine cyanine dye, has been used to achieve selective hyperthermic effects in target tissues via near-infrared irradiation. To implement IR783 as a photothermal agent, IR783 biodistribution must be calibrated to achieve a constant and uniform concentration in target cells. Accordingly, we developed micelle-encapsulated IR783 (IR783 micelles) and evaluated their effectiveness as photothermal drugs. MethodsIn vitro, the photothermic effects of free IR783 and IR783 micelle solutions induced by near-infrared light irradiation were analyzed. Additionally, we investigated the mechanism of cell death mediated by photothermal therapy using free IR783 and IR783 micelles in mouse breast cancer (EMT6) cells. In vivo, the efficacy of photothermal therapy with both free IR783 and IR783 micelles was examined in EMT6-bearing mice. ResultsIn vitro, the temperature of free and micelle-encapsulated IR783 solutions increased after near-infrared irradiation. Near-infrared irradiation with free IR783 and IR783 micelles induced cytotoxicity in cancer cells by generating heat. In vivo, IR783 micelles elicited more preferential tumor tissue uptake and enhanced the antitumor effects of photothermal therapy at a lower light dose relative to free IR783. ConclusionsOverall, these results suggest that IR783 micelles could accumulate in mouse breast cancer tissues and exhibit enhanced antitumor effects when used as a photothermal therapy, with superior effects obtained at 2.1 W/cm2 (252 J/cm2) compared with that of free IR783.

Targeting RNA helicase DDX3X with a small molecule inhibitor for breast cancer bone metastasis treatment

Patients who present with breast cancer bone metastasis only have limited palliative treatment strategies and efficacious drug treatments are needed. In breast cancer patient data, high levels of the RNA helicase DDX3 are associated with poor overall survival and bone metastasis. Consequently, our objective was to target DDX3 in a mouse breast cancer bone metastasis model using a small molecule inhibitor of DDX3, RK-33. Histologically confirmed live imaging indicated no bone metastases in the RK-33 treated cohort, as opposed to placebo-treated mice. We generated a cell line from a bone metastatic lesion in mouse and found that it along with a patient-derived bone metastasis cell line gained resistance to conventional chemotherapeutics but not to RK-33. Finally, differential levels of DDX3 were observed in breast cancer patient metastatic bone samples. Overall, this study indicates that DDX3 is a relevant clinical target in breast cancer bone metastasis and that RK-33 can be a safe and effective treatment for these patients.

Enhanced anti-tumor efficacy of S3I-201 in breast cancer mouse model through Wharton jelly- exosome

ObjectiveExosomes, membrane-enveloped vesicles found in various cell types, including Wharton’s jelly mesenchymal stem cells, play a crucial role in intercellular communication and regulation. Their use as a cell-free nanotechnology and drug delivery system has attracted attention. Triple-negative breast cancer (TNBC) is a major global health problem and is characterized by a high mortality rate. This study investigates the potential of Wharton’s Jelly mesenchymal stem cell-derived exosomes (WJ-Exo) as carriers of S3I-201 and their effects on STAT3 expression in breast cancer cell lines, and evaluates whether these exosomes can enhance the anti-tumor effect of S3I-201.MethodsThe filtered WJ-Exos were analyzed by Transmission Electron Microscopy (TEM), Scanning electron microscopy (SEM), Dynamic Light Scattering (DLS), flow cytometry, and Western blotting. These exosomes were then used for loading with S3I-201, resulting in the nano-formulation WJ-Exo(S3I-201). The effect of WJ-Exo(S3I-201) on 4T1 cancer cells was investigated in vitro using MTT assay, flow cytometry, wound healing assay, Western blotting and Quantitative Real-Time Polymerase chain reaction (qPCR) analysis. Finally, the therapeutic efficacy of the nano-formulation was investigated in vivo using a tumor-bearing mouse model.ResultsIn vitro experiments showed that co-incubation of 4T1 cells with the nano-formulation resulted in a significant reduction in p-STAT3 levels, induction of apoptosis, modulation of Bcl-2, Bax and caspase-3 protein and gene expression, and inhibition of migration. In vivo, treatment of tumor-bearing mice with WJ-Exo(S3I-201) showed a strong antitumor effect that exceeded the efficacy observed in the S3I-201 group.ConclusionOur results demonstrate that WJ-Exo is an effective carrier for targeting S3I-201 to tumor cells and enhances the therapeutic efficacy of S3I-201 in tumor-bearing mice.

Lattice expansion in ruthenium nanozymes improves catalytic activity and electro-responsiveness for boosting cancer therapy

Nanozymes have been attracting widespread interest for the past decade, especially in the field of cancer therapy, due to their intrinsic catalytic activities, strong stability, and ease of synthesis. However, enhancing their catalytic activity in the tumor microenvironment (TME) remains a major challenge. Herein, we manipulate catalytic activities of Ru nanozymes via modulating lattice spacing in Ru nanocrystals supported on nitrogen-doped carbon support, to achieve improvement in multiple enzyme-like activities that can form cascade catalytic reactions to boost cancer cell killing. In addition, the lattice expansion in Ru nanocrystals improve the responsiveness of the nanozymes to self-powered electric field, achieving maximized cancer therapeutic outcome. Under the electrical stimulation provided by a human self-propelled triboelectric device, the Ru-based nanozyme (Ru1000) with a lattice expansion of 5.99% realizes optimal catalytic performance and cancer therapeutic outcome of breast cancer in female tumor-bearing mice. Through theoretical calculations, we uncover that the lattice expansion and electrical stimulation promote the catalytic reaction, simultaneously, by reducing the electron density and shifting the d-band center of Ru active sites. This work provides opportunities for improving the development of nanozymes.

Platelet Angiopoietin-1 Protects Against Murine Models of Tumor Metastasis.

In addition to their fundamental roles in preserving vascular integrity, platelets also contribute to tumor angiogenesis and metastasis. However, despite being a reservoir for angiogenic and metastatic cytokines, platelets also harbor negative regulators of tumor progression. Angpt1 (angiopoietin-1) is a cytokine essential for developmental angiogenesis that also protects against tumor cell metastasis through an undefined mechanism. Although activated platelets release Angpt1 from α-granules into circulation, the contributions of platelet Angpt1 to tumor growth, angiogenesis, and metastasis have not been investigated. Using cytokine arrays and ELISAs, we first compared platelet Angpt1 levels in breast and melanoma mouse tumor models to tumor-free controls. We then assessed tumor growth and metastasis in mice lacking megakaryocyte and platelet Angpt1 (Angpt1Plt KO). The spontaneous metastasis of mammary-injected tumor cells to the lungs was quantified using RT-PCR (reverse transcription-polymerase chain reaction). The lung colonization of intravenously injected tumor cells and tumor cell extravasation were determined using fluorescent microscopy and flow cytometry. Platelet Angpt1 is selectively upregulated in the PyMT (polyoma middle tumor antigen) breast cancer mouse model, and platelets are the principal source of Angpt1 in blood circulation. While primary tumor growth and angiogenesis were unaffected, Angpt1Plt KO mice had both increased spontaneous lung metastasis and tumor cell lung colonization following mammary or intravenous injection, respectively. Although platelet Angpt1 did not affect initial tumor cell entrapment in the lungs, Angpt1Plt KO mice had increased tumor cell retention and extravasation. Serum from Angpt1Plt KO mice increased endothelial permeability and reduced VE (vascular endothelial)-cadherin expression at endothelial junctions compared with serum from control mice (Angpt1WT). Platelets provide an intravascular source of Angpt1 that restrains tumor metastasis by preserving the lung microvasculature to limit tumor cell extravasation.