Mouse Model Of Cancer Research Articles

Engineered extrachromosomal oncogene amplifications promote tumorigenesis.

Focal gene amplifications are among the most common cancer-associated mutations1 but have proven challenging to engineer in primary cells and model organisms. Here we describe a general strategy to engineer large (more than 1 Mbp) focal amplifications mediated by extrachromosomal DNAs (ecDNAs)2 in a spatiotemporally controlled manner in cells and in mice. By coupling ecDNA formation with expression of selectable markers, we track the dynamics of ecDNA-containing cells under physiological conditions and in the presence of specific selective pressures. We also apply this approach to generate mice harbouring Cre-inducible Myc- and Mdm2-containing ecDNAs analogous to those occurring in human cancers. We show that the engineered ecDNAs spontaneously accumulate in primary cells derived from these animals, promoting their proliferation, immortalization and transformation. Finally, we demonstrate the ability of Mdm2-containing ecDNAs to promote tumour formation in an autochthonous mouse model of hepatocellular carcinoma. These findings offer insights into the role of ecDNA-mediated gene amplifications in tumorigenesis. We anticipate that this approach will be valuable for investigating further unresolved aspects of ecDNA biology and for developing new preclinical immunocompetent mouse models of human cancers harbouring specific focal gene amplifications.

Developing Multiple Media Approach to Investigate Reproducible Characteristic VOCs of Lung Cancer Cells.

Cellular volatile organic compound (VOC) detection is crucial for studying lung cancer biomarkers. However, the reported VOC biomarkers from the same cell line seem to be inconsistent across different research groups. It is possibly related to the variation in culture media, and the result obtained by a conventional single medium approach (SMA) depends on what medium is used in the cell experiment. This study proposes a multiple media approach (MMA) to investigate reproducible characteristic VOCs of lung cancer cells. Using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) in combination with untargeted analysis, we conducted two independently repetitive experiments to compare lung cancer cells (A549) and normal lung cells (BEAS-2B) under three culture media conditions (RPMI 1640, DMEM, and Ham's F12). Both experiments indicated that, compared with 62-96 VOCs obtained by the SMA, only two VOCs (3-methyl-1-butanol and 2-methyl-1-butanol) were reproducibly achieved by the MMA. Moreover, their concentrations were significantly lower in lung cancer cells than in normal cells. Further targeted analysis confirmed the downregulation trend of both VOCs in subcutaneous and primary tumor tissues from the lung cancer model mouse. The present work demonstrated that the MMA cell experiment, just like the multicenter trials for cell lines, can facilitate the discovery of reproducible characteristic VOCs. This provides a cellular experimental basis and scientific evidence for lung cancer biomarker investigation and even breath biopsy technique development.

Spatiotemporal Mapping of Lymphatic Metastases in Gastric Cancer Using Tumor-Trackable and Enzyme-Activatable Near-Infrared Fluorescent Nanoprobes.

Sentinel lymph node biopsy holds significant importance in cancer management, yet the challenge persists in early detection and precise resection of metastasis lymph nodes (LNs) due to the absence of specific and sensitive optical probes. This study reports metastatic LN reporters (MLRs) with an activatable optical output for accurate spatiotemporal mapping of lymphatic metastases in gastric cancer. MLRs are self-assembled entities incorporating mixed amphiphiles with a lipophilic tail and a tumor-targeting ligand or a fluorescent moiety that is caged with a switch cleavable by tumor-specific β-galactosidase (β-Gal). After draining into LNs, MLRs selectively activate their near-infrared fluorescence in the presence of spreading tumor cells. In orthotopic gastric cancer mouse models, the representative reporter MLR1 distinguishes macro/micrometastatic LNs from benign LNs and enables early detection of skip LNs metastasis patterns in a spatial-dependent manner. Such an active sensing mechanism provides a high level of sensitivity and specificity comparable to those of flow cytometry analysis. In surgically resected patient specimens, MLR1 differentiates cancerous tissues and metastatic LNs from normal tissues and benign LNs within 1 h. This study thus presents NIRF nanoprobes that permit facile detection of LN metastases in GC patient samples and highlights a generic translatable nanoprobe design for understanding metastatic progression.

Development and Characterization of a High-Affinity Selective Galectin-3 Mouse Tool Compound in Mouse Models of Cancer.

The interest in galectin-3 as a drug target in the cancer and fibrosis space has grown during the past few years with several new classes of compounds being developed. The first orally available galectin-3 inhibitor, GB1211 (h-galectin-3 Kd = 0.025 μM), is currently in phase 2 clinical trials. Due to structural differences between human and mouse galectin-3 a significant reduction in mouse galectin-3 affinity is observed for most highly potent human galectin-3 inhibitors including GB1211 (m-galectin-3 Kd = 0.77 μM). Pharmacokinetic experiments in mouse dosing GB1211 up to 100 mg/kg results in free plasma levels below m-galectin-3 Kd, which is not comparable to the data observed in humans. To better support translation into clinical studies, a new improved mouse galectin-3 tool compound, GB2095, was developed. Dosing this new compound in in vivo syngeneic mouse models of cancer resulted in reduction of the growth of breast and melanoma cancers.

HDC downregulation induced by chronic stress promotes ovarian cancer progression via the IL-6/STAT3/S100A9 pathway

ObjectiveThis study aimed to investigate the underlying mechanism of chronic stress promoting ovarian cancer growth comorbid with depression and evaluate the potential role of histamine (HIS) in treating this comorbidity.MethodsChronic unpredictable mild stress (CUMS) was used to establish a comorbid mouse model of ovarian cancer and depression. The behavioral phenotypes were assessed using the sucrose preference test (SPT), tail suspension test (TST), forced swimming test (FST), and open field test (OFT). Ovarian cancer growth was monitored by tracking the tumor volume and weight. Histidine decarboxylase (HDC) expression in the tumor tissue was analyzed using Western blot and qRT-PCR techniques. The serum levels of inflammatory factors (IL-6 and IL-17A), stress hormones (norepinephrine, NE and cortisol, and COR), histamine, and 5-hydroxytryptamine (5-HT) were detected by enzyme-linked immunosorbent assay (ELISA). In vitro experiments were conducted to explore the direct impacts of stress hormones on A2780 and ES-2 ovarian cancer cell lines, as well as the modulation of these effects by histamine. HDC knockdown and overexpression approaches were used to study its regulatory role in the IL-6/STAT3/S100A9 signaling pathway.ResultsChronic stress not only induced depressive behaviors but also accelerated ovarian cancer growth in mice by downregulating HDC expression in tumors, whereas exogenous HIS treatment alleviated depressive symptoms, suppressed cancer growth, and countered the decreased levels of HIS and increased levels of IL-6, IL-17A, NE, COR, and 5-HT induced by CUMS. Furthermore, HIS positively modulated the immune response by increasing the populations of CD3+T and CD8+ T cells and reducing IL-17A secretion. In vitro experiments revealed that stress hormones downregulated HDC expression, consequently promoting cancer cell proliferation, migration, and invasion via the IL-6/STAT3/S100A9 pathway. Knockdown of HDC activated this pathway, whereas HDC overexpression inhibited its activation.ConclusionChronic stress leads to the downregulation of HDC expression, thereby facilitating the progression of ovarian cancer through the IL-6/STAT3/S100A9 pathway. HIS might serve as a potential molecule for treating the comorbidities of ovarian cancer and depression.

Evaluation of Metastasis Inhibition by ABD-IL-2 Compared to Human IL-2 in a Breast Cancer Mouse Model.

Interleukin-2 (IL-2) is a well-known cytokine that plays a crucial role in stimulating immune cells, including natural killer (NK) cells and cytotoxic T cells. It has been studied as an immunotherapy for a variety of diseases, including cancer. However, due to its short serum half-life, high doses of IL-2 are required which can result in systemic toxicities like capillary leak syndrome. To demonstrate the enhanced antitumor efficacy of Albumin Binding Domain-conjugated IL-2 (ABD-IL-2) at a lower dose compared to IL-2. IL-2 and ABD-IL-2 were purified using Ni-NTA resin with a histidine sequence added to their C-terminal region for purification purpose. Peripheral blood lymphocytes were stimulated with IL-2 and ABD-IL-2 to assess their function. 4T1 cells were injected into BALB/c mice to establish a breast cancer model with metastasis evaluated in the lungs. Both recombinant proteins significantly stimulated T lymphocyte proliferation compared to the negative control (P=0.000, P=0.001). Administration of both proteins reduced the size of isolated tumors in the breast cancer mouse model. The control group had more nodules and larger lung metastatic centers (P=0.000). Metastasis to secondary lymphoid organs occurred only in the control group. By using ABD-IL-2 at a one-third concentration compared to IL-2, we aimed to reduce administration toxicity associated with high doses of IL-2 in immunotherapy. This approach shows potential for improving IL-2-based treatments while minimizing adverse effects.

CHD1L Inhibitor OTI-611 Synergizes with Chemotherapy to Enhance Antitumor Efficacy and Prolong Survival in Colorectal Cancer Mouse Models

Colorectal cancer (CRC) is one of the most prevalent and deadly forms of cancer. It is universally treated with a combination of the DNA damaging chemotherapy drugs irinotecan, 5-Fluorouracil (5-FU), and oxaliplatin. CHD1L is a novel oncogene that plays critical roles in chromatin remodeling and DNA damage repair, as well as the regulation of malignant gene expression. We show that an inhibitor of CHD1L, OTI-611, when combined with chemotherapy significantly increases DNA damage in CRC cell lines. OTI-611 also synergizes with SN-38, 5-FU, and oxaliplatin in killing CRC tumor organoids. We also demonstrate that, as in breast cancer, OTI-611 traps CHD1L, PARP1, and PARP2 onto chromatin. The entrapment of CHD1L causes the deprotection of PAR chains in the nucleus, ultimately resulting in cell death by CHD1Li-mediated PARthanatos, as measured by AIF translocation to the nucleus. Finally, the combination of low doses of OTI-611 with irinotecan significantly reduces tumor volume and extends survival in CRC xenograft mouse models compared to irinotecan alone. The combination of standard of care chemotherapy drugs with CHD1Li represents a promising advancement in future therapeutic strategies for CRC and other cancers driven by CHD1L.

Antitumor Activity and Immunostimulant Properties of Liposomes Containing Rosemary Extract on a Mouse Model of Colorectal Cancer.

Rosemary (Ros) is a member of the Lamiaceae family known for its antitumor properties. However, its low water solubility and impaired bioavailability are limiting factors when using rosemary extract. Liposomes are synthetic vesicles that offer permeability, improved bioavailability, and lack of immunogenicity and toxicity, making them ideal for delivering various drugs. To prepare liposomes (HSPC/Chol/mPEG2000-DSPE) containing rosemary alcoholic extract (LipRos) and evaluate its antitumor properties in a mouse model of colorectal cancer (CRC). LipRos were prepared and characterized. CRC was induced in Balb/c mice by subcutaneous injection of C26 cells, and tumor size was monitored continuously. The MTT assay was performed to evaluate cytotoxicity, and liver and kidney function tests were conducted to assess safety. The expression of the pro-apoptotic gene B-cell-lymphoma-2 (Bcl-2), the anti-apoptotic gene Bcl-2-associated-X-protein (Bax), and the expression of cytokines Tumor-necrosis-factor-alpha (TNF-α), Transforming-growth-factor-beta (TGF-β), and Interferon-gamma (IFN-γ) were investigated using real-time PCR. Flow cytometry was used to evaluate the count of cytotoxic (CTL) and regulatory T lymphocytes (Tregs) in spleen and tumor tissue. The results showed that the size of liposomal formulations and their encapsulation efficiency were 113.4 nm and 85%, respectively. The MTT assay demonstrated insignificant cytotoxicity of LipRos on splenocytes, and the tumor size was significantly reduced in the LipRos group (P=0.00045). LipRos also significantly decreased Bcl-2 gene expression (P=0.0086), increased Bax and IFN-γ gene expression (P=0.031), and enhanced the infiltration of CTLs in tumor tissue (P=0.023). This study showed that PEGylated (Poly-Ethylene-Glycol) liposomes containing rosemary extract exhibit an antitumor effect on C26 colorectal cancer cells through multiple mechanisms. These findings can be utilized in future studies.

Asparagus officinalis L. extract exhibits anti-proliferative and anti-invasive effects in endometrial cancer cells and a transgenic mouse model of endometrial cancer.

Endometrial cancer is the most common malignancy of the female reproductive system in the United States. Asparagus officinalis is a versatile, nutrient-dense, low-calorie vegetable that contains various bioactive metabolites that have shown a variety of biologic functions beneficial to health. The metabolites from asparagus officinalis extracts or asparagus officinalis extracts exhibit significant anti-tumorigenic activity in some pre-clinical models of cancer. Endometrial cancer cells were used to study the effects of asparagus officinalis on anti-proliferation, anti-invasion and increased sensitivity to cisplatin, and obese and lean Lkb1 fl/fl p53 fl/fl mouse model of endometrial cancer was used to study the role of asparagus officinalis in tumor growth. Treatment with increasing concentrations of Asparagus officinalis extracts significantly inhibited cell proliferation, reduced glycolytic activity, induced cellular stress and apoptosis, caused cell cycle G1 arrest, increased the sensitivity of cells to cisplatin, reduced cell adhesion and invasion, and activation of AMPK and inhibition of the AKT/mTOR and MAPK signaling pathways in endometrial cancer cells. Moreover, asparagus officinalis extracts suppressed cell adhesion and invasion through the modulation of the epithelial-to-mesenchymal transition process. Asparagus officinalis extract treatment for 4weeks resulted in a significant reduction in tumor growth in Lkb1 fl/fl p53 fl/fl mice under both obese and lean conditions, with a decrease in Ki-67 and vascular endothelial growth factor expression and an increase in Bip expression in endometrial tumors. These findings provide strong preclinical evidence for the potential therapeutic benefit of asparagus officinalis extract as a novel dietary strategy in the treatment of endometrial cancer. Further clinical trials of dietary intervention of asparagus officinalis or combination with cisplatin in patients with endometrial cancer are warranted.

Nanomedicine based on chemotherapy-induced immunogenic death combined with immunotherapy to enhance antitumor immunity.

Chemo-immunotherapy based on inducing tumor immunogenic cell death (ICD)with chemotherapy drugs has filled the gaps between traditional chemotherapy and immunotherapy. It is verified that paclitaxel (PTX) can induce breast tumor ICD. From this basis, a kind of nanoparticle that can efficiently deliver different drug components simultaneously is constructed. The purpose of this study is for the sake of exploring the scheme of chemotherapy-induced ICD combined with other immunotherapy to enhance tumor immunogenicity and inhibit the growth, metastasis, and recurrence of breast tumors, so as to provide a research basis for solving the tough problem of breast cancer treatment. Nanomedicine loaded with PTX, small interference RNA that suppresses CD47 expression (CD47siRNA, siCD47), and immunomodulator R848 were prepared by the double emulsification method. The hydrodynamic diameter and zeta potential of NP/PTX/siCD47/R848 were characterized. Established the tumor-bearing mice model of mouse breast cancer cell line (4T1) in situ and observed the effect of intravenous injection of NP/PTX/siCD47/R848 on the growth of 4T1 tumor in situ. Flow cytometry was used to detect the effect of drugs on tumor immune cells. NP/PTX/siCD47/R848 nano-drug with tumor therapeutic potential were successfully prepared by double emulsification method, with particle size of 121.5 ± 4.5nm and surface potential of 36.1 ± 2.5mV. The calreticulin on the surface of cell membrane and extracellular ATP or HMGB1 of 4T1 cells increased through treatment with NPs. NP/PTX-treated tumor cells could cause activation of BMDCs and BMDMs. After intravenous injection, NP/PTX could quickly reach the tumor site and accumulate for 24h. The weight and volume of tumor in situ in the breast cancer model mice injected with nanomedicine through the tail vein were significantly lower than those in the PBS group. The ratio of CD8+/CD4+ T cells in the tumor microenvironment and the percentage of dendritic cells in peripheral blood increased significantly in breast cancer model mice injected with nano-drugs through the tail vein. Briefly, the chemotherapeutic drug paclitaxel can induce breast cancer to induce ICD. The nanomedicine which can deliver PTX, CD47siRNA, and R848 at the same time was prepared by double emulsification. NP/PTX/siCD47/R848 nano-drug can be enriched in the tumor site. The experiment of 4T1 cell tumor-bearing mice shows that the nano-drug can enhance tumor immunogenicity and inhibit breast tumor growth, which provides a new scheme for breast cancer treatment. (Graphical abstract).

Tumor-derived miR-9-5p-loaded EVs regulate cholesterol homeostasis to promote breast cancer liver metastasis in mice

Cancer cells secrete extracellular vesicles (EV) encapsulating bioactive cargoes to facilitate inter-organ communication in vivo and are emerging as critical mediators of tumor progression and metastasis, a condition which is often accompanied by a dysregulated cholesterol metabolism. Whether EVs are involved in the control of cholesterol homeostasis during tumor metastasis is still undefined and warrant further investigation. Here, we find that breast cancer-derived exosomal miR-9-5p induces the expression of HMGCR and CH25H, two enzymes involved in cholesterol synthesis and the conversion of 25-hydroxycholesterol from cholesterol by targeting INSIG1, INSIG2 and ATF3 genes in the liver. Notably, in vivo miR-9-5p antagomir treatment and genetic CH25H ablation prevents tumor metastasis in a mouse model of breast cancer. Thus, our findings reveal the regulatory mechanism of tumor-derived miR-9-5p in liver metastasis by linking oxysterol metabolism and Kupffer cell polarization, shedding light on future applications for cancer diagnosis and treatment.

Engineered platelets as targeted protein degraders and application to breast cancer models.

Clinical application of chimeric molecules for targeted protein degradation has been limited by unfavorable drug-like properties and biosafety concerns arising from nonspecific biodistribution after systemic administration. Here we develop a method to engineer platelets for degradation of either intracellular or extracellular proteins of interest (POIs) in vivo by covalently labeling heat shock protein 90 (HSP90) in platelets with a POI ligand. The degrader platelets (DePLTs) target wound areas and undergo activation. Depending on the tethered POI ligand and transport mechanism of the prelabeled HSP90, activated DePLTs can mediate targeted protein degradation in the target cell through the ubiquitin-proteasome machinery or the lysosome. HSP90 packaged into platelet-derived microparticles uses the ubiquitin-proteasome system to degrade intracellular POIs, whereas released free HSP90 redirects extracellular POIs to lysosomal degradation. In postsurgical breast cancer mouse models, DePLTs engineered with corresponding POI ligands effectively degrade intracellular bromodomain-containing protein 4 or extracellular programmed cell death ligand 1, thereby suppressing cancer recurrence or metastasis.

Concurrent intratumoural Treg cell depletion and CD8+ T cell expansion via a cleavable anti-4-1BB-interleukin-15 fusion protein.

Potent agonists of the inducible co-stimulatory receptor 4-1BB are too toxic for patients with advanced cancer. Here, on the basis of observations of a weak agonist of 4-1BB depleting regulatory T (Treg) cells within the tumour microenvironment without leading to substantial restoration of dysfunctional cytotoxic T cells (CTLs), we show that effective tumour control can be achieved via concurrent Treg cell depletion and CTL expansion through an anti-4-1BB antibody fused to interleukin-15 (IL-15) via a peptide sensitive to tumour proteases. In mouse models of advanced cancers, intraperitoneal injection of the bifunctional protein attenuated the activity of the interleukin mostly in the periphery of the primary tumour while allowing for the expansion of CTLs within the tumour microenvironment, led to more effective tumour inhibition and to lower systemic toxicity than treating the cancers with combinatorial treatment with unlinked anti-4-1BB antibody and IL-15, and reduced the resistance of tumours to checkpoint blockade. Concurrent eradication of Treg cells and activation of tumour-infiltrating lymphocytes may represent a general strategy for the effective control of advanced metastatic tumours.

Jaboticaba Peel Extract Exerts Chemopreventive Effects in Transgenic Mouse Model of Prostate Cancer

Introduction: Angiogenesis, oxidative stress, and epigenetic alterations involved in prostate cancer (PCa) are associated with different risk factors, such as a high-fat diet (HFD), overweight, and obesity. Jaboticaba peel extract (PJE) has shown antiproliferative, antiangiogenic, and antioxidant activities in the prostate of senile mice. Method: This study aimed to evaluate the effect of PJE on the dorsolateral prostate microenvironment in male transgenic mice for the prostate adenocarcinoma model, considering different pathological alterations, changed or unchanged by HFD, focusing on histopathology, and molecules related to extracellular matrix (ECM), oxidative stress, angiogenesis, and Dact-1. Western blotting and immunohistochemistry were performed on Dact-1-associated tumor suppressor genes in transgenic mice. Mice were fed HFD and received patented jaboticaba peel extract (PJE) treatment. The plasma levels of systemic oxidative stress were evaluated. Results: Our results showed that PJE protected the dorsolateral prostate against proliferation and increased MMP9, TGFβ, and VEGF levels. PJE reduced oxidative stress and lipid peroxidation by modulating catalase, SOD 2, and 4HNE. PJE exhibited an epigenetic action, evidenced by increased Dact-1 gene expression in PCa. Conclusion: PJE could be a natural protector of PCa and prostate lesions associated with HFD intake.

Therapeutic Potential of Silica Nanoparticles, Cisplatin, and Quercetin on Ovarian Cancer: In Vivo Model

The present study evaluated the effect of silica nanoparticles, quercetin, and cisplatin against ovarian cancer. Cisplatin is a potent antineoplastic agent but has greater toxicity against cancer. Quercetin is a powerful flavonoid with remarkable anti-cancer activity due to its anti-apoptotic nature. Forty female albino rats were randomly divided into eight groups, with five rats per group. Group 1 (G1) was normal control, G2 received Carboxymethylcellulose; G3 was the normal control and treated with quercetin, G4 was given silica nanoparticles, G5 was treated with cisplatin. G6 was the tumor control. Tumor induction was done by 7, 12-dimethylbenz (a) anthracene (DMBA), G7 was treated with quercetin-cisplatin-silica nanoparticles, and in G8 quercetin-cisplatin silica nanoparticles were used to treat the induced tumor. Chemically synthesized silica nanoparticles were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and Fourier Transform Infrared (FTIR). After the treatment, animals were sacrificed and tested for biochemical and hormonal assays. G6 displayed increased body weight and a significant rise in CA125 as compared to G1. G6 also exhibited an altered hormonal profile, with a particular increase in estrogen, FSH, and testosterone, along with reduced LH and progesterone levels. Lipid profile, liver enzymes, and renal parameters (urea and creatinine) increased in G6, but G8 significantly ameliorated all damaging effects of DMBA as observed in G6. The current study revealed that silica nanoparticles combined with cisplatin and quercetin demonstrated greater protection against drastic changes induced by carcinogens in ovarian cancer mice models.

Modulating the tumor microenvironment in a mouse model of colon cancer using a combination of HIF-1α inhibitors and Toll-Like Receptor 7 agonists.

The immunosuppressive tumor microenvironment (TME) plays a pivotal role in the response to various anticancer therapies, such as immune and chemotherapeutic agents. In this study, the synergistic effects of gene-targeting HIF-1α siRNA combined with Toll-Like Receptor 7 agonist on TME remodeling were investigated in a mouse model of colorectal cancer (CRC). A HIF-1α-specific siRNA duplex was formulated based on the ionic gelation of tripolyphosphate (TPP) with cationic chitosan (CH) as a nanoplex and evaluated in terms of size, charge, polydispersity index and gel retardation assay. MTT assay was conducted to assess the cytotoxicity of the specific siRNA duplex against CT26 cells. Hypoxic condition was generated to evaluate the gene and protein expression levels of HIF-1α, respectively. CT26 mouse model was established to assess the synergistic effect of silencing HIF-1α combined with oxaliplatin (OXA) and imiquimod (IMQ) on tumor growth. The mean diameter of the CH/siRNA nanoparticles was 243 ± 6 nm, as confirmed with Micrograph scanning electron microscope. There were no significant differences observed between the CT26 cells treated with nanoparticles alone and the untreated cells, indicating that these nanoparticles are safe and physiologically biocompatible (p ≥ 0.05). Triple combination therapy involving HIF-1α siRNA, OXA, and IMQ significantly retarded tumor growth and led to elevated levels of cytokines linked to cellular immunity (INF-γ and IL-12) compared with those in the other groups (P < 0.05). The positive correlation coefficient (r = 0.68) between tumor size and HIF-1α expression levels was statistically significant (P = 0.003). Compared with those in the control group, the expression levels of the anti-inflammatory cytokines IL-10 and IL-4 significantly decreased (P < 0.05). In conclusion, our findings suggest that inhibiting HIF-1α could serve as a rational strategy to enhance the antitumor response in the TME.

Imaging tumor and ascites-associated macrophages in a mouse model of metastatic ovarian cancer

BackgroundTumor-Associated Macrophages (TAMs) play a critical role in the pathogenesis and progression of ovarian cancer, a lethal gynecologic malignancy. [124I]iodo-DPA-713 is a PET radiotracer that is selectively trapped within reactive macrophages. We have employed this radioligand here as well as a fluorescent analog to image TAMs associated with primary tumors, secondary pulmonary metastases and gastrointestinal tract-associated macrophages, associated with ascites accumulation in a syngeneic mouse model of metastatic ovarian cancer. Intact female C57BL/6 mice were engrafted with ID8-Defb29-VEGF tumor pieces. One month after engraftment, the mice were selected for positive bioluminescence to show primary and secondary tumor burden and were then scanned by PET/MRI with [124I]iodo-DPA-713, observing a 24 h uptake time. PET data were overlayed with T2-weighted MRI data to facilitate PET uptake tissue identity. Additionally, mice were imaged ex vivo using Near IR Fluorescence (NIRF), capturing the uptake and sequestration of DPA-713-IRDye800CW, a fluorescent analog of the radioligand used here. Additionally, cell culture uptake of DPA-713-IRDye680LT in ID8-DEFb29-VEGF, IOSE hTERT and RAW264.7 cells was conducted to measure tracer uptake in ovarian cancer cells, ovarian epithelial cells and macrophage.ResultsPET/MRI data show an intense ring of radiotracer uptake surrounding primary tumors. PET uptake is also associated with lung metastases, but not healthy lung. Mice displaying ascites also display PET uptake along the gastrointestinal tract while sham-operated mice show minimal gastrointestinal uptake. All mice show specific kidney uptake. Mice imaged by NIRF confirmed TAMs uptake mostly at the rim of primary tumors while 1 mm secondary tumors in the lungs displayed robust, homogeneous uptake of the radio- and fluorescent analog. Ex vivo biodistribution of [124I]iodo-DPA-713 showed that contralateral ovaries in middle-stage disease had the highest probe uptake with tissues sampled in mid- and late-stage disease showing increasing uptake.Conclusion[124I]iodo-DPA-713 and DPA-713-IRDye800CW sensitively identify and locate TAMs in a syngeneic mouse model of metastatic ovarian cancer.

Hyperactivity of the IL-33-ILC2s-IL-13-M-MDSCs axis promotes cervical cancer progression

The interleukin-33(IL-33) – group 2 innate lymphoid cells (ILC2s) – interleukin-13(IL-13) – monocytic myeloid-derived suppressor cells (M-MDSCs) axis plays a critical role in promoting immune evasion in tumors; however, its specific function in cervical cancer remains poorly understood. In this study, we observed that the proportion of IL-33-ILC2s-IL-13-M-MDSCs were significantly elevated in both cervical cancer patients and the subcutaneous U14 cervical cancer mouse model, compared to normal controls. Our results suggest that IL-33 stimulates ILC2s to secrete IL-13, which, in turn, regulates M-MDSCs to enhance their immune evasion capabilities. Notably, in vitro blockade of IL-33 and IL-13 partially restored the levels and functions of both ILC2s and M-MDSCs. In conclusion, these findings imply that the overactivation of the IL-33-ILC2s-IL-13-M-MDSCs axis may contribute to cervical cancer progression. However, further in vivo blockade studies are required to fully elucidate the precise mechanisms underlying this interaction and to assess its potential therapeutic implications for cervical cancer.

Therapeutic co-assemblies for synergistic NSCLC treatment through dual topoisomerase I and tubulin inhibitors

Camptothecin (CPT) and podophyllotoxin (PPT) function as topoisomerase (TOP) I and tubulin inhibitors, respectively, with potent anticancer effects in a variety of cancers. Despite its promise, the clinical applicability of the combination of CPT and PPT faces challenges, including potential side effect and limited therapeutic efficacy. In this study, we designed co-assembly nanomedicines with the different weight (w/w) ratios of amphiphilic Evans blue conjugated CPT prodrug (EB-ss-CPT) and PPT molecules, denoted as ECT Nano. The co-assembly of EB-ss-CPT and PPT without other excipients has nearly 100% drug loading efficiency and high drug loading content of PPT of up to 74.29 ± 0.90 wt%. Notably, the ECT Nano (1:2) equipped with the ability to inhibit TOP I activity and tubulin polymerization, which provided a highly efficient strategy to improve synergistic efficacy and decrease side toxicity in non-small cell lung cancer mouse model. This work represents a step forward to the development of practical applications for dual TOP I and tubulin inhibitors and especially hopeful to the rational design of combination nanomedicine for therapeutic purposes.

C/EBPβ-dependent autophagy inhibition hinders NK cell function in cancer

NK cells are endowed with tumor killing ability, nevertheless most cancers impair NK cell functionality, and cell-based therapies have limited efficacy in solid tumors. How cancers render NK cell dysfunctional is unclear, and overcoming resistance is an important immune-therapeutic aim. Here, we identify autophagy as a central regulator of NK cell anti-tumor function. Analysis of differentially expressed genes in tumor-infiltrating versus non-tumor NK cells from our previously published scRNA-seq data of advanced human prostate cancer shows deregulation of the autophagic pathway in tumor-infiltrating NK cells. We confirm this by flow cytometry in patients and in diverse cancer models in mice. We further demonstrate that exposure of NK cells to cancer deregulates the autophagic process, decreases mitochondrial polarization and impairs effector functions. Mechanistically, CCAAT enhancer binding protein beta (C/EBPβ), downstream of CXCL12-CXCR4 interaction, acts as regulator of NK cell metabolism. Accordingly, inhibition of CXCR4 and C/EBPβ restores NK cell fitness. Finally, genetic and pharmacological activation of autophagy improves NK cell effector and cytotoxic functions, which enables tumour control by NK and CAR-NK cells. In conclusion, our study identifies autophagy as an intracellular checkpoint in NK cells and introduces autophagy regulation as an approach to strengthen NK-cell-based immunotherapies.