Model Of Human Breast Cancer Research Articles

Comparative analysis of the molecular subtype landscape in canine and human mammary gland tumors

Breast cancers in humans belong to one of several intrinsic molecular subtypes each with different tumor biology and different clinical impact. Mammary gland tumors in dogs are proposed as a relevant comparative model for human breast cancer; however, it is still unclear whether the intrinsic molecular subtypes have the same significance in dogs and humans. Using publicly available data, we analyzed gene expression and whole-exome sequencing data from 158 canine mammary gland tumors. We performed molecular subtyping using the PAM50 method followed by subtype-specific comparisons of gene expression characteristics, mutation patterns and copy number profiles between canine tumors and human breast tumors from The Cancer Genome Atlas (TCGA) breast cancer cohort (n = 1097). We found that luminal A canine tumors greatly resemble luminal A human tumors both in gene expression characteristics, mutations and copy number profiles. Also, the basal-like canine and human tumors were relatively similar, with low expression of luminal epithelial markers and high expression of genes involved in cell proliferation. There were, however, distinct differences in immune-related gene expression patterns in basal-like tumors between the two species. Characteristic HER2-enriched and luminal B subtypes were not present in the canine cohort, and we found no tumors with high-level ERBB2 amplifications. Benign and malignant canine tumors displayed similar PAM50 subtype characteristics. Our findings indicate that deeper understanding of the different molecular subtypes in canine mammary gland tumors will further improve the value of canines as comparative models for human breast cancer.

Increased lung metastasis with sevoflurane in breast cancer surgery is associated with VEGF and elevated vascular permeability by VEGF in a mouse model of human breast cancer.

e13060 Background: An on-going controversy is whether general anesthetics used in cancer surgery substantially influence the outcome of cancer patients. Thousands of cancer patients undergo surgery with hope of cure. However, postoperative metastasis remains a deadly disease that affects millions of lives, even with all the recent therapeutic advancements. Anesthesia is required for surgical resection of solid tumors and we have shown that general anesthetics substantially influences the process of breast cancer lung metastasis through increasing pulmonary permeability in animal models. Our previous study demonstrates that inhaled anesthetic sevoflurane used during resecting primary breast tumors promotes lung metastasis via IL6 pathway in syngeneic model of murine 4T1 breast cancer cells, compared with an intravenous anesthetic propofol. Methods: Xenograft model of human MDA-MB 231 breast cancer of spontaneous metastasis was utilized in this study to evaluate the effect of commonly used general anesthetics including sevoflurane and propofol on breast cancer lung metastasis and explore the potential mechanism. Results: In this study we show that the metastatic promoting effect of sevoflurane is associated with elevated secretion of VEGF and increased vascular permeability in xenograft model of human MDA-MB 231 breast cancer of spontaneous metastasis. Cytokine array profiling reveals that the mice receiving sevoflurane have increased levels of pro-angiogenic factor VEGF in serum and lung tissues. Sevoflurane enhances the expression level of VEGFR on HUVEC cells. Furthermore, sevoflurane disrupts endothelial monolayer in vitro and elevates pulmonary vascular permeability in vivo. The sevoflurane-promoted breast cancer lung metastasis is reversed by DC101, an antibody targeting mouse VEGFR-2. Conclusions: Our results show that the inhaled anesthetic sevoflurane during surgical removal of primary tumor alter the course of metastasis through regulating secretion of VEGF and associated vascular remodeling. The mechanistic study of general anesthetics on cancer cell metastasis establishes the causal link and could provide the potential therapeutic intervention and guide the clinical trials.

Phase 1 first-in-human trial of MTB-9655, the first oral inhibitor of ACSS2, in patients with advanced solid tumors.

e20609 Background: ACSS2 catalyzes the ligation of acetate with Co-enzyme A to generate Acetyl-CoA. Selection to an acetate dependent state has been demonstrated and is associated with the induction of ACSS2 gene expression in certain human cancers. The ACSS2 gene is amplified in human breast cancers, and its expression is up-regulated in human colorectal, breast, ovarian and lung cancers. MTB-9655 is a potent (IC50 = 0.15nM in biochemical, and EC50 = 3nM in cellular assays) oral inhibitor of ACSS2 and induces anti-tumor effects in xenograft mouse models of human colorectal, breast and lung cancers that express high levels of ACSS2. Methods: Using a combined accelerated (single patient for the first two dose levels) and 3+3 dose escalation and dose expansion design, MTB-9655 was administered on a once daily (QD) schedule in 21-day cycles in a Phase 1 trial to assess safety, tolerability, PK and potential anti-tumor activity in patients with advanced solid tumors. Re-staging was performed every 2 cycles. Results: To-date, 10 subjects have received MTB-9655 at doses up to 225mg. MTB-9655 was absorbed rapidly post oral dosing with a half-life of 6-12 hours. Dose proportional exposure was observed on day 1 of the first dosing cycle, and steady-state exposure was noted between day 8 and day 1 of the second dosing cycle. Dose limiting toxicities or Grade 3 treatment-related adverse events (AEs) have not been observed up to the 225mg dose level. The most common AE was nausea (29%). Low grade increase in bilirubin levels was observed in 1 patient at 225mg dose, without changes in other liver enzyme levels. Increased bilirubin levels were readily reversed with dose interruption. As MTB-9655 is a 729nM inhibitor of the UGT1A1 enzyme, the increase in bilirubin levels is likely attributed to off-target UGT1A1 inhibitory activity. Conclusions: MTB-9655 has been well tolerated, and the safety profile was predictable based on preclinical studies in rodents and non-human primates. Dose proportional plasma drug levels were observed and predicted to have reached biologically active levels. Expected increase in bilirubin levels was observed in 1 patient, which may be used as a marker of significant drug exposure. MTD has not reached up to the 225mg dose and the dose escalation is continuing. Development of MTB-9655 is planned as a single agent, and based on animal model studies, in combination with standard of care platinum-based agents and gemcitabine. Clinical trial information: NCT04990739.

Micro RNA differential expression profile in canine mammary gland tumor by next generation sequencing.

Canine mammary gland tumors are very common and represent a potential model of human breast cancer, and microRNA (miRNAs) are promising biomarkers and therapeutic targets for these tumors. Accordingly, we aimed to identify miRNAs differentially expressed in canine mammary gland tumors using next generation sequencing (NGS), with subsequent confirmatory qPCR and target gene analyses. Mammary gland tissue was collected from healthy dogs (n=7) and dogs with suspected tumors (n=80). A subset of samples was analyzed with NGS to identify differentially expressed miRNAs with CLC Genome Workbench. Normal (n=10), tumor-adjacent (n=6), and tumor-bearing (n=76) mammary gland tissue samples were analyzed for the identified miRNAs using qPCR. An in silico analysis (TargetScan) was performed to predict the miRNAs' target genes using gene ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database (DAVID). We identified four miRNAs (cfa-miR-1-3p, cfa-miR-133a-3p, cfa-miR-133b-3p, and cfa-miR-133c-3p) as down regulated in canine mammary gland tumor tissues relative to normal and tumor adjacent tissues. KEGG analysis revealed the potential target genes of cfa-miR-1-3p are related to the Rap1 signaling pathway, adherens junction, and Ras signaling pathway, and those of the miR-133 family are related to the TGF-beta signaling pathway, synaptic vesicle cycle, and sphingolipid signaling pathway. In combination, these target genes are related to the regulation of transcription and DNA binding transcription (GO analysis), and the Hippo signaling pathway, adherens junction, and endocytosis (KEGG analysis). Accordingly, we suggest these four miRNAs are promising potential biomarker candidates for canine mammary gland tumors warranting further investigation.

Micro- and Nanosecond Pulses Used in Doxorubicin Electrochemotherapy in Human Breast and Colon Cancer Cells with Drug Resistance.

(1) Background: Pulsed electric field (PEF) techniques are commonly used to support the delivery of various molecules. A PEF seems a promising method for low permeability drugs or when cells demonstrate therapy resistance and the cell membrane becomes an impermeable barrier. (2) Methods: In this study, we have used doxorubicin-resistant and sensitive models of human breast cancer (MCF-7/DX, MCF-7/WT) and colon cancer cells (LoVo, LoVoDX). The study aimed to investigate the susceptibility of the cells to doxorubicin (DOX) and electric fields in the 20–900 ns pulse duration range. The viability assay was utilized to evaluate the PEF protocols’ efficacy. Cell confluency and reduced glutathione were measured after PEF protocols. (3) Results: The obtained results showed that PEFs significantly supported doxorubicin delivery and cytotoxicity after 48 and 72 h. The 60 kV/cm ultrashort pulses × 20 ns × 400 had the most significant cytotoxic anticancer effect. The increase in DOX concentration provokes a decrease in cell viability, affected cell confluency, and reduced GSSH when combined with the ESOPE (European Standard Operating Procedures of Electrochemotherapy) protocol. Additionally, reactive oxygen species after PEF and PEF-DOX were detected. (4) Conclusions: Ultrashort electric pulses with low DOX content or ESOPE with higher DOX content seem the most promising in colon and breast cancer treatment.

MitoQ Prevents Human Breast Cancer Recurrence and Lung Metastasis in Mice

Simple SummaryEntry in the metastatic phase is often devastating for cancer patients. Metastases originate from metastatic progenitor cells that are selected in the primary tumor and which simultaneously possess several phenotypic capabilities, including migration, invasion, and clonogenicity. We previously provided in vitro evidence that these features are collectively enforced by mitochondrial superoxide in a paradigm where mitochondria act as metabolic sensors of the tumor microenvironment and produce subcytotoxic levels of superoxide to prime metastatic progenitor cells. We also showed that these metastatic traits can be collectively countered by MitoQ, a mitochondria-targeted antioxidant that selectively deactivates mitochondrial superoxide. Here, we further establish that MitoQ prevents primary tumor recurrence after surgery, tumor take and metastasis as a whole, notably in a model of human breast cancer in mice. Since MitoQ already successfully passed Phase I clinical trials, our findings support the development of this drug as a preventive treatment against breast cancer metastasis.In oncology, the occurrence of distant metastases often marks the transition from curative to palliative care. Such outcome is highly predictable for breast cancer patients, even if tumors are detected early, and there is no specific treatment to prevent metastasis. Previous observations indicated that cancer cell mitochondria are bioenergetic sensors of the tumor microenvironment that produce superoxide to promote evasion. Here, we tested whether mitochondria-targeted antioxidant MitoQ is capable to prevent metastasis in the MDA-MB-231 model of triple-negative human breast cancer in mice and in the MMTV-PyMT model of spontaneously metastatic mouse breast cancer. At clinically relevant doses, we report that MitoQ not only prevented metastatic take and dissemination, but also local recurrence after surgery. We further provide in vitro evidence that MitoQ does not interfere with conventional chemotherapies used to treat breast cancer patients. Since MitoQ already successfully passed Phase I safety clinical trials, our preclinical data collectively provide a strong incentive to test this drug for the prevention of cancer dissemination and relapse in clinical trials with breast cancer patients.

Honokiol Inhibits HIF-1α-Mediated Glycolysis to Halt Breast Cancer Growth

Background: Hypoxia-inducible factor-1α (HIF-1α) induces the expression of glycolysis-related genes, which plays a direct and key role in Warburg effect. In a recent study, honokiol (HNK) was identified as one of the potential agents that inhibited the HIF-1α signaling pathway. Because the HIF- 1α pathway is closely associated with glycolysis, we investigated whether HNK inhibited HIF-1α-mediated glycolysis. Methods: The effects of HNK on HIF-1α-mediated glycolysis and other glycolysis-related genes’ expressions, cancer cells apoptosis and tumor growth were studied in various human breast cancer models in vitro and in vivo. We performed the following tests: extracellular acidification and oxygen consumption rate assays, glucose uptake, lactate, and ATP assays for testing glycolysis; WST-1 assay for investigating cell viability; colony formation assay for determining clonogenicity; flow cytometry for assessing cell apoptosis; qPCR and Western blot for determining the expression of HIF-1α, GLUT1, HK2 and PDK1. The mechanisms of which HNK functions as a direct inhibitor of HIF-1α were verified through the ubiquitination assay, the Co-IP assay, and the cycloheximide (CHX) pulse-chase assay. Results: HNK increased the oxygen consumption rate while decreased the extracellular acidification rate in breast cancer cells; it further reduced glucose uptake, lactic acid production and ATP production in cancer cells. The inhibitory effect of HNK on glycolysis is HIF-1α-dependent. HNK also downregulated the expression of HIF-1α and its downstream regulators, including GLUT1, HK2 and PDK1. A mechanistic study demonstrated that HNK enhanced the self-ubiquitination of HIF-1α by recruiting two E3 ubiquitin ligases (UFL1 and BRE1B). In vitro, HNK inhibited cell proliferation and clonogenicity, as well as induced apoptosis of cancer cells. These effects were also HIF1α-dependent. In vivo, HNK inhibited tumor growth and HIF-1α-mediated glycolysis. Conclusion: HNK has an inhibitory effect on HIF-1α-mediated glycolysis in human breast cancer. Our research revealed a new mechanism of HNK as an anti-cancer drug, thus representing a novel strategy to improve the prognosis of cancer.

Ultrasound and magnetic resonance imaging of cyclic arginine glycine aspartic acid-gadopentetic acid-polylactic acid in human breast cancer by targeting αvβ3 in xenograft-bearing nude mice

ABSTRACT Effective early detection shows the potential to reduce breast cancer mortality. This study aimed to establish a targeted contrast agent for Magnetic Resonance Imaging (MRI)/ultrasound dual-modality molecular radiography for breast cancer. The cyclic arginine-glycine-aspartate-gadopentetic acid-polylactic acid (cRGD and Gd-DTPA) coated by multi-functional blank poly (lactic-co-glycolic acid) (PLGA) nanoparticles) was successfully constructed by chemical synthesis method with high stability. The safety of cRGD-Gd-DTPA-PLGA was demonstrated in vitro and in vivo, and their affinity to breast cancer cells was revealed. Moreover, MRI/ultrasound dual-modality molecular radiography in vitro showed that as the concentration of contrast agent increased, the echo enhancement and signal intensity of MRI imaging were also elevated. The mouse models of human breast cancer also indicated significant target enhancements of cRGD-Gd-DTPA-PLGA magnetic nanoparticles in the mouse tumor. Thus, cRGD-Gd-DTPA-PLGA magnetic nanoparticles were suggested as qualified MRI/ultrasound dual-modality molecular radiography contrast agent. We further explored the targeting mechanism of cRGD-Gd-DTPA-PLGA in breast cancer. The results showed that αvβ3 was highly expressed in breast cancer tissues, and cRGD-Gd-DTPA-PLGA used for MRI/ultrasound dual-modality molecular radiography by targeting αvβ3. Additionally, we found that the signal-to-noise ratio of MRI was positively correlated with microvessel density (MVD). The cRGD-Gd-DTPA-PLGA dynamicly and quantitatively monitored breast cancer by monitoring the state of neovascularization. In conclusion, in the present study, we successfully constructed the cRGD-Gd-DTPA-PLGA magnetic nanoparticles for MRI/ultrasound dual-modality molecular radiography. The cRGD-Gd-DTPA-PLGA showed potential in early detection and diagnosis of metastasis, and dynamic evaluation of the efficacy of molecular targeted therapy of integrin αvβ3.

Celastrol Inhibits Canine Mammary Tumor Cells by Inducing Apoptosis via the Caspase Pathway.

Canine mammary tumor is a serious disease threatening the health of dogs and can be used as a research model for human breast cancer. The study of canine mammary tumor has a role in improving the welfare of dogs. Most common canine mammary tumor chemotherapy drugs have limited effects and drug resistance. Celastrol is an extract of Tripterygium wilfordii, which has a wide range of biological activities, including significant anti-tumor effects. At present, celastrol has not been used in the clinical treatment for canine mammary tumor. This study investigated the anti-tumor properties of celastrol through in vitro assay of cell proliferation inhibition, cell colony, cell migration, and invasion; flow cytometry, qPCR, and Western Blot methods were used to explore the anti-tumor mechanism of celastrol. The results showed that celastrol can inhibit the proliferation of canine mammary tumor cells in vitro, and decrease the migration and invasion ability of canine mammary tumor cells. We also found that celastrol can upregulate Cleaved Caspase-3 and Cleaved Caspase-9 protein expression levels to promote cell apoptosis, and can regulate cell cycle-related proteins to induce cell cycle arrest. In summary, celastrol may inhibit canine mammary tumor cells through the Caspase pathway, providing a new direction for anti-canine mammary tumor drugs, and is expected to become a new anti-cancer drug for canine mammary tumors.

Evaluation of Curcumin Therapeutic Effects on Histological Subtypes of Canine Mammary Gland Tumours

Canine mammary gland tumors (CMGTs) are the most frequent types of cancer in bitches and proposed as a model of human breast cancer. The anticancer effect of curcumin on human breast cancer has been extensively studied. The aim of this study was to evaluate the therapeutic effect of curcumin in two different histologies (simple carcinoma [SC] and squamous cell carcinoma [SCC]) of CMGTs. Primary canine mammary cells were isolated from the tumoral tissues surgically resected from two bitches (Case 1 and Case 2). Cell viability, apoptotic percentage, cell cycle progression and the changes in the cell morphology were evaluated. Curcumin inhibited the growth of both SC (Case 1) and SCC (Case 2) cells. However, Case 1 cells (43.48% ± 3.87% at 0.5 µM) were more sensitive to curcumin than Case 2 cells (59.36% ± 2.09% at 0.5 µM). Curcumin induced total apoptotic cell death through G0/G1 arrest, and this effect was more profound in Case 1 cells. Furthermore, cytoplasmic vacuolization, apoptotic bodies and membrane blebbing were observed in both cells following curcumin treatment. Our findings provide a novel approach for the effects of curcumin as a natural compound on CMGTs. Further investigations should be performed to investigate the molecular mechanisms of the differences in curcumin efficacy for different histological subtypes.

NGS-identified miRNAs in Canine Mammary Gland Tumors Show Unexpected Expression Alterations in qPCR Analysis.

Canine mammary gland tumors (MGTs), as a potential model of human breast cancer, have a well-defined histological classification system. MicroRNA (miRNA) expression is a key part of the molecular signatures of both MGTs and human breast cancer, although the signatures alone do not yet provide a sufficient basis for definitive diagnosis. In this study, we investigated the association between miRNA expression patterns and histological classification. Mammary gland tissue was collected from healthy dogs (n=7) and dog patients (n=80). Further samples (n=5) were obtained from established MGT cell lines. We targeted miRNAs differentially expressed in metastatic tumor tissue versus non-metastatic and normal tissue. A subset of samples was analyzed using small RNA next generation sequencing (NGS) with subsequent qPCR. Six differentially expressed miRNAs were selected from the NGS analysis and submitted for large-scale qPCR. The large-scale qPCR analysis revealed greater alternations in miRNA expression. Large-scale analysis, based on 79 samples, revealed a hierarchical clustering based on selected miRNAs that did not strikingly match the histopathological subtype classification. We successfully investigated the large-scale miRNA expression pattern in canine MGT and provided the whole miRNA expression. The selected miRNA demonstrated that there is no straightforward mapping between molecular signatures and histological classification of canine MGTs at the miRNA level.

Novel Combination of Multi-Wall Carbon Nanotubes and Gold Nano-Composite for Photothermal Therapy in Human Breast Cancer Model

Novel Combination of Multi-Wall Carbon Nanotubes and Gold Nano-Composite for Photothermal Therapy in Human Breast Cancer Model

Mesoporous Doxorubicin-Loaded Polydopamine Nanoparticles Coated with a Platelet Membrane Suppress Tumor Growth in a Murine Model of Human Breast Cancer.

Bringing together photothermal therapy and chemotherapy (photothermal-chemotherapy, PT-CT) is a highly promising clinical approach but requires the development of intelligent multifunctional delivery vectors. In this work, we prepared mesoporous polydopamine nanoparticles (MPDA NPs) loaded with the chemotherapeutic drug doxorubicin (DOX). These NPs were then coated with the platelet membrane (PLTM). The coated MPDA NPs are spherical and clearly mesoporous in structure. They have a particle size of approximately 184 nm and pore size of ca. 45 nm. The NPs are potent photothermal agents and efficient DOX carriers, with increased rates of drug release observed in vitro in conditions representative of the tumor microenvironment. The NPs are preferentially taken up by cancer cells but not by macrophage cells, and while cytocompatible with healthy cells are highly toxic to cancer cells. An in vivo murine model of human breast cancer revealed that the NPs can markedly slow the growth of a tumor (ca. 9-fold smaller after 14 days' treatment), have extended pharmacokinetics compared to free DOX (with DOX still detectable in the bloodstream after 24 h when the NPs are applied), and are highly targeted with minimal off-site effects on the heart, liver, spleen, kidney, and lungs.

Exosomes Derived from Radioresistant Breast Cancer Cells Promote Therapeutic Resistance in Naïve Recipient Cells.

Radiation resistance is a significant challenge in the treatment of breast cancer in humans. Human breast cancer is commonly treated with surgery and adjuvant chemotherapy/radiotherapy, but recurrence and metastasis upon the development of therapy resistance results in treatment failure. Exosomes are extracellular vesicles secreted by most cell types and contain biologically active cargo that, when transferred to recipient cells, can influence the cells’ genome and proteome. We propose that exosomes secreted by radioresistant (RR) cells may be able to disseminate the RR phenotype throughout the tumour. Here, we isolated exosomes from the human breast cancer cell line, MDA-MB-231, and the canine mammary carcinoma cell line, REM134, and their RR counterparts to investigate the effects of exosomes derived from RR cells on non-RR recipient cells. Canine mammary cancer cells lines have previously been shown to be excellent translational models of human breast cancer. This is consistent with our current data showing that exosomes derived from RR cells can increase cell viability and colony formation in naïve recipient cells and increase chemotherapy and radiotherapy resistance, in both species. These results are consistent in cancer stem cell and non-cancer stem cell populations. Significantly, exosomes derived from RR cells increased the tumoursphere-forming ability of recipient cells compared to exosomes derived from non-RR cells. Our results show that exosomes are potential mediators of radiation resistance that could be therapeutically targeted.

Evaluation of the immunomodulatory activity of thalidomide on tumor-associated macrophages in the 4T1 murine metastatic breast cancer model

ABSTRACT The present work evaluated the immunomodulatory effect of thalidomide (Thal) at different doses on tumor-associated macrophages (TAMs) using a mouse model of human breast cancer. Mice were inoculated with 4T1 cells in the left flank and treated with Thal once a day at concentrations of 50, 100, and 150mg/kg body weight from the 5th day until the 28th day of tumor inoculation. The tumors were sized, proliferation index and TAMs count were evaluated in primary tumors and metastatic lungs. In addition, the metastasis rate was evaluated in the lungs. Thal at 150mg/kg significantly decreased tumor growth, proliferation index, and TAMs infiltration in primary tumors. Conversely, a higher number of TAMs and lower proliferation index were observed in metastatic lungs in mice treated with 150mg/kg of Thal. Furthermore, Thal at 150mg/kg significantly decreased the metastatic nodules in the lungs. Our findings demonstrated that Thal treatment considerably decreased the primary tumor and lung metastasis in mice associated with different TAM infiltration effects in these sites.

Enhanced Anti-Tumor Effect of Folate-Targeted FA-AMA-hyd-DOX Conjugate in a Xenograft Model of Human Breast Cancer

Folate-aminocaproic acid-doxorubicin (FA-AMA-hyd-DOX) was firstly synthesized by our group. It was indicated that FA-AMA-hyd-DOX was pH-responsive, and had strong cytotoxicity on a folate receptor overexpressing cell line (KB cells) in vitro. The aim of our study was to further explore the potential use of FA-AMA-hyd-DOX as a new therapeutic drug for breast cancer. The cellular uptake and the antiproliferative activity of the FA-AMA-hyd-DOX in MDA-MB-231 cells were measured. Compared with DOX, FA-AMA-hyd-DOX exhibited higher targeting ability and cytotoxicity to FR-positive tumor cells. Subsequently, the tissue distribution of FA-AMA-hyd-DOX was studied, and the result confirmed that DOX modified by FA can effectively increase the selectivity of drugs in vivo. After determining the maximum tolerated dose (MTD) of FA-AMA-hyd-DOX in MDA-MB-231 tumor-bearing nude mice, the antitumor effects and the in vivo safety of FA-AMA-hyd-DOX were systematically evaluated. The data showed that FA-AMA-hyd-DOX could effectively increase the dose of DOX tolerated by tumor-bearing nude mice and significantly inhibit MDA-MB-231 tumor growth in vivo. Furthermore, FA-AMA-hyd-DOX treatment resulted in almost no obvious damage to the mice. All the positive data suggest that FA-targeted FA-AMA-hyd-DOX is a promising tumor-targeted compound for breast cancer therapy.

Curcumin Administered in Combination with Glu-GNPs Induces Radiosensitivity in Transplanted Tumor MDA-MB-231-luc Cells in Nude Mice.

Curcumin is a type of plant polyphenol extracted from Curcuma longa L. rhizome, which demonstrates antitumor activity in breast cancer cells in vitro. To investigate the combined effect and possible mechanism of curcumin and glucose-gold nanoparticles (Glu-GNPs), the radiosensitivity of breast carcinoma xenografts was assessed in nude mice. MDA-MB-231 cells labeled with firefly luciferase were inoculated into the mammary fatty pads of nude mice to establish a transplantation tumor model of human breast cancer. The tumor-bearing mice were treated with different drugs (curcumin, Glu-GNPs, and cisplatin) for 3 weeks prior to radiotherapy. The body weights and tumor volumes of the mice were measured in regular intervals. Tumor bioluminescence intensity was determined in real-time using an in vivo bioluminescence imaging system to monitor tumor growth. Transplanted tumor tissue samples were taken for hematoxylin and eosin (HE) staining, and the expression of VEGF, HSP90, HIF-1α, and MMP9 was evaluated via reverse transcription-quantitative PCR or immunohistochemistry. The results revealed that the breast tumor-bearing nude mouse model was successfully established, as evidenced by a stable expression of luciferase. Curcumin inhibited the growth of tumors without causing significant weight loss in mice. Furthermore, additive inhibition was demonstrated when curcumin was administered in combination with Glu-GNPs and irradiation. Tumor bioluminescence intensity was decreased in the model group following curcumin, Glu-GNPs, and irradiation treatment. HE staining demonstrated that transplanted tumors were malignant, with necrotic tissue exhibited centrally. It was concluded that curcumin administered in combination with Glu-GNPs and X-ray irradiation could reduce the protein expression of VEGF, HSP90, HIF-1α, and MMP9 in tumor tissue when compared with the model group. Curcumin and Glu-GNPs administered with X-ray irradiation significantly inhibited tumor growth and induced radiosensitivity, which may be associated with the inhibition of angiogenesis in tumor tissue.

An immune-humanized patient-derived xenograft model of estrogen-independent, hormone receptor positive metastatic breast cancer

BackgroundMetastatic breast cancer (MBC) is incurable, with a 5-year survival rate of 28%. In the USA, more than 42,000 patients die from MBC every year. The most common type of breast cancer is estrogen receptor-positive (ER+), and more patients die from ER+ breast cancer than from any other subtype. ER+ tumors can be successfully treated with hormone therapy, but many tumors acquire endocrine resistance, at which point treatment options are limited. There is an urgent need for model systems that better represent human ER+ MBC in vivo, where tumors can metastasize. Patient-derived xenografts (PDX) made from MBC spontaneously metastasize, but the immunodeficient host is a caveat, given the known role of the immune system in tumor progression and response to therapy. Thus, we attempted to develop an immune-humanized PDX model of ER+ MBC.MethodsNSG-SGM3 mice were immune-humanized with CD34+ hematopoietic stem cells, followed by engraftment of human ER+ endocrine resistant MBC tumor fragments. Strategies for exogenous estrogen supplementation were compared, and immune-humanization in blood, bone marrow, spleen, and tumors was assessed by flow cytometry and tissue immunostaining. Characterization of the new model includes assessment of the human tumor microenvironment performed by immunostaining.ResultsWe describe the development of an immune-humanized PDX model of estrogen-independent endocrine resistant ER+ MBC. Importantly, our model harbors a naturally occurring ESR1 mutation, and immune-humanization recapitulates the lymphocyte-excluded and myeloid-rich tumor microenvironment of human ER+ breast tumors.ConclusionThis model sets the stage for development of other clinically relevant models of human breast cancer and should allow future studies on mechanisms of endocrine resistance and tumor-immune interactions in an immune-humanized in vivo setting.

Fra-2 overexpression upregulates pro-metastatic cell-adhesion molecules, promotes pulmonary metastasis, and reduces survival in a spontaneous xenograft model of human breast cancer

PurposeThe transcription factor Fra-2 affects the invasive potential of breast cancer cells by dysregulating adhesion molecules in vitro. Previous results suggested that it upregulates the expression of E- and P-selectin ligands. Such selectin ligands are important members of the leukocyte adhesion cascade, which govern the adhesion and transmigration of cancer cells into the stroma of the host organ of metastasis. As so far, no in vivo data are available, this study was designed to elucidate the role of Fra-2 expression in a spontaneous breast cancer metastasis xenograft model.MethodsThe effect of Fra-2 overexpression in two stable Fra-2 overexpressing clones of the human breast cancer cell line MDA MB231 on survival and metastatic load was studied after subcutaneous injection into scid and E- and P-selectin-deficient scid mice.ResultsFra-2 overexpression leads to a significantly shorter overall survival and a higher amount of spontaneous lung metastases not only in scid mice, but also in E- and P-deficient mice, indicating that it regulates not only selectin ligands, but also selectin-independent adhesion processes.ConclusionThus, Fra-2 expression influences the metastatic potential of breast cancer cells by changing the expression of adhesion molecules, resulting in increased adherence to endothelial cells in a breast cancer xenograft model.

Safety and Efficacy Evaluation In Vivo of a Cationic Nucleolipid Nanosystem for the Nanodelivery of a Ruthenium(III) Complex with Superior Anticancer Bioactivity.

Simple SummaryThe availability of selective, effective, and safe anticancer agents is a major challenge in the field of cancer research. As part of a multidisciplinary research project, in recent years our group has proposed an original class of nanomaterials for the delivery of new anticancer drugs based on ruthenium(III) complexes. In cellular models, these nanosystems have been shown to be effective in counteracting growth and proliferation of human breast cancer cells. Compared to conventional metallochemotherapeutics such as platinum-based agents whose clinical practice is associated with serious undesirable effects, ruthenium complexes share improved biochemical profiles making them more selective towards cancer cells and less cytotoxic to healthy cells. Their combination with biocompatible nanocarriers further enhances these promising features, as here showcased by our research carried out in an animal model which underscores the efficacy and safety in vivo of one of our most promising ruthenium-based nanosystems.Selectivity and efficacy towards target cancer cells, as well as biocompatibility, are current challenges of advanced chemotherapy powering the discovery of unconventional metal-based drugs and the search for novel therapeutic approaches. Among second-generation metal-based chemotherapeutics, ruthenium complexes have demonstrated promising anticancer activity coupled to minimal toxicity profiles and peculiar biochemical features. In this context, our research group has recently focused on a bioactive Ru(III) complex—named AziRu—incorporated into a suite of ad hoc designed nucleolipid nanosystems to ensure its chemical stability and delivery. Indeed, we proved that the structure and properties of decorated nucleolipids can have a major impact on the anticancer activity of the ruthenium core. Moving in this direction, here we describe a preclinical study performed by a mouse xenograft model of human breast cancer to establish safety and efficacy in vivo of a cationic Ru(III)-based nucleolipid formulation, named HoThyRu/DOTAP, endowed with superior antiproliferative activity. The results show a remarkable reduction in tumour with no evidence of animal suffering. Blood diagnostics, as well as biochemical analysis in both acute and chronic treated animal groups, demonstrate a good tolerability profile at the therapeutic regimen, with 100% of mice survival and no indication of toxicity. In addition, ruthenium plasma concentration analysis and tissue bioaccumulation were determined via appropriate sampling and ICP-MS analysis. Overall, this study supports both the efficacy of our Ru-containing nanosystem versus a human breast cancer model and its safety in vivo through well-tolerated animal biological responses, envisaging a possible forthcoming use in clinical trials.