Breast Tumor-bearing Mice Research Articles

Evaluation of a novel monoclonal antibody against tumor-associated MUC1 for diagnosis and prognosis of breast cancer.

There is still a great unmet medical need concerning diagnosis and treatment of breast cancer which could be addressed by utilizing specific molecular targets. Tumor-associated MUC1 is expressed on over 90 % of all breast cancer entities and differs strongly from its physiological form on epithelial cells, therefore presenting a unique target for breast cancer diagnosis and antibody-mediated immune therapy. Utilizing an anti-tumor vaccine based on a synthetically prepared glycopeptide, we generated a monoclonal antibody (mAb) GGSK-1/30, selectively recognizing human tumor-associated MUC1. This antibody targets exclusively tumor-associated MUC1 in the absence of any binding to MUC1 on healthy epithelial cells thus enabling the generation of breast tumor-specific radiolabeled immune therapeutic tools.Methods: MAb GGSK-1/30 was used for immunohistochemical analysis of human breast cancer tissue. Its desferrioxamine (Df')-conjugate was synthesized and labelled with 89Zr. [89Zr]Zr-Df'-GGSK-1/30 was evaluated as a potential PET tracer. Binding and pharmacokinetic properties of [89Zr]Zr-Df'-GGSK-1/30 were analyzed in vitro using human and murine cell lines that express tumor-associated MUC1. Self-generated primary murine breast cancer cells expressing human tumor-associated MUC1 were transplanted subcutaneously in wild type and human MUC1-transgenic mice. The pharmacology of [89Zr]Zr-Df'-GGSK-1/30 was investigated using breast tumor-bearing mice in vivo by PET/MRT imaging as well as by ex vivo organ biodistribution analysis.Results: The mAb GGSK-1/30 stained specifically human breast tumor tissue and can be possibly used to predict the severity of disease progression based on the expression of the tumor-associated MUC1. For in vivo imaging, the Df'-conjugated mAb was radiolabeled with a radiochemical yield of 60 %, a radiochemical purity of 95 % and an apparent specific activity of 6.1 GBq/µmol. After 7 d, stabilities of 84 % in human serum and of 93 % in saline were observed. In vitro cell studies showed strong binding to human tumor-associated MUC1 expressing breast cancer cells. The breast tumor-bearing mice showed an in vivo tumor uptake of >50 %ID/g and clearly visible specific enrichment of the radioconjugate via PET/MRT.Principal conclusions: Tumor-associated MUC1 is a very important biomarker for breast cancer next to the traditional markers estrogen receptor (ER), progesterone receptor (PR) and HER/2-neu. The mAb GGSK-1/30 can be used for the diagnosis of over 90% of breast cancers, including triple negative breast cancer based on biopsy staining. Its radioimmunoconjugate represents a promising PET-tracer for breast cancer imaging selectively targeting breast cancer cells.

Effects of cisplatin on photosensitizer-mediated photodynamic therapy in breast tumor-bearing nude mice.

ObjectiveThis study aimed to evaluate the potential effects of cisplatin on photodynamic therapy (PDT) in breast cancer using a breast tumor-bearing mouse model.MethodsIn this study, breast tumor (experimental mammary tumour-6 cell)-bearing nude mice were used as experimental animals. Photolon® (photosensitizer, 2.5 mg/kg body weight [BW]) was injected intraperitoneally; after 2 hours, the tumors were irradiated (660 nm, 80 J/cm2) using a diode laser tool. Cisplatin (3 mg/kg BW) was injected intraperitoneally 1 hour before the Photolon® injection.ResultsTumor volume increased over time in the control group and was not different from that in the cisplatin group. In the PDT group, the tumor volume increased on day 3, but not on day 7. In the cisplatin+PDT group, tumor volume increased on day 3 but decreased on day 7. There was no significant difference in the levels of thiobarbituric acid reactive substance (TBARS) in tumor tissues between the control and cisplatin groups. The levels of TBARS in the cisplatin+PDT group were higher (47%) than those in the PDT group. Analysis of tumor tissue transcriptomes showed that the expression of genes related to the inflammatory response including CL and XCL genes increased, while that of Fn1 decreased in the cisplatin+PDT group compared with the PDT group.ConclusionThese results suggest that cisplatin enhances the therapeutic effect of PDT in a breast tumor-bearing mouse model. However, further clinical studies involving patients with breast cancer is needed.

Effect of quercetin on the anti-tumor activity of cisplatin in EMT6 breast tumor-bearing mice.

ObjectiveThe purpose of this study was to determine the effect of quercetin on the antitumor activity of cisplatin and its side-effects.MethodsEMT6 cells, a mouse breast cancer cell line, were injected subcutaneously in mice to generate a breast tumor-bearing mouse model. Experimental groups were divided into four groups: control (C), quercetin (Q), cisplatin (CP), and cisplatin+quercetin (CP+Q).ResultsThe tumor volume of the CP+Q group was significantly lower than that of the CP group. Serum blood urea nitrogen and creatinine levels in the CP+Q group were lower than those in the CP group. Renal γ-glutamyltranspeptidase and alkaline phosphatase activities were significantly higher in the CP+Q group than in the CP group, and the content of renal thiobarbituric acid reactive substance was significantly lower in the CP+Q group than that in the CP group. These results suggested that quercetin and cisplatin synergistically increased cellular toxicity in breast cancer cells and mediated cancer growth inhibition, thereby enhancing the antitumor effect of cisplatin compared to when only cisplatin was administered. Quercetin also reduced renal toxicity, which arose as a potential a side effect of cisplatin.ConclusionThe enhanced antitumor effect of cisplatin and decreased renal toxicity after quercetin treatment suggested the applicability of quercetin as an adjuvant for chemotherapeutic agents.

Reduced Breast Tumor Growth after Immunization with a Tumor-Restricted MUC1 Glycopeptide Conjugated to Tetanus Toxoid.

Preventive vaccination against tumor-associated endogenous antigens is considered to be an attractive strategy for the induction of a curative immune response concomitant with a long-lasting immunologic memory. The mucin MUC1 is a promising tumor antigen, as its tumor-associated form differs from the glycoprotein form expressed on healthy cells. Due to aberrant glycosylation in tumor cells, the specific peptide epitopes in its backbone are accessible and can be bound by antibodies induced by vaccination. Breast cancer patients develop per se only low levels of T cells and antibodies recognizing tumor-associated MUC1, and clinical trials with tumor-associated MUC1 yielded unsatisfactory therapeutic effects, indicating an urgent need to improve humoral immunity against this tumor entity. Herein, we demonstrate that preventive vaccination against tumor-associated human MUC1 results in a specific humoral immune response, a slowdown of tumor progression and an increase in survival of breast tumor-bearing mice. For preventive vaccination, we used a synthetic vaccine containing a tumor-associated glycopeptide structure of human MUC1 coupled to Tetanus Toxoid. The glycopeptide consists of a 22mer huMUC1 peptide with two immune dominant regions (PDTR and GSTA), glycosylated with the sialylated carbohydrate STN on serine-17. PyMT (polyomavirus middle T-antigen) and human MUC1 double-transgenic mice expressing human tumor-associated MUC1 on breast tumor tissue served as a preclinical breast cancer model.

Identifying the Most Effective Hydatid Cyst Fluid Fraction for Anticancer Vaccination of 4T1 Breast Tumor-Bearing Mice.

Background:The hydatid cyst fluid antigens have high homology with cancer cell antigens and also exhibit considerable immunogenicity. Therefore, their utilization for cancer immunization can cause an effective antitumor immune response. However, the main challenge is identifying the most effective antigens for this purpose.Methods:Hydatid cyst fluid fractions including the glycolipid fraction, glycoprotein fraction, 78 kDa fraction, and antigen B fraction were prepared. Then, the BALB/c mice were immunized against different antigens and, subsequently, 4T1 cells were subcutaneously implanted. The tumors' growth, metastasis, and tumor-bearing mice survival were assessed in different immunized groups. In addition, IL-2, IL-4, IFN-γ, and TNF-α serum levels were estimated to evaluate the immune system response.Results:BALB/c mice immunization against the complete hydatid cyst fluid antigens exhibited more significant inhibition of the tumors' growth and metastasis and increase of tumor-bearing mice survival in comparison with its derived fractions. However, the 78 kDa fraction exhibited the best results according to the same factors in comparison with all the prepared fractions.Conclusions:The 78 kDa fraction of the hydatid cyst fluid was the most effective fraction of hydatid cyst fluid for immunization against 4T1 breast tumors.

Analysis of the Expression and Regulation of PD-1 Protein on the Surface of Myeloid-Derived Suppressor Cells (MDSCs).

Myeloid-derived suppressor cells (MDSCs) that are able to suppress T cell function are a heterogeneous cell population frequently observed in cancer, infection, and autoimmune disease. Immune checkpoint molecules, such as programmed death 1 (PD-1) expressed on T cells and its ligand (PD-L1) expressed on tumor cells or antigen-presenting cells, have received extensive attention in the past decade due to the dramatic effects of their inhibitors in patients with various types of cancer. In the present study, we investigated the expression of PD-1 on MDSCs in bone marrow, spleen, and tumor tissue derived from breast tumor-bearing mice. Our studies demonstrate that PD-1 expression is markedly increased in tumor-infiltrating MDSCs compared to expression in bone marrow and spleens and that it can be induced by LPS that is able to mediate NF-κB signaling. Moreover, expression of PD-L1 and CD80 on PD-1+ MDSCs was higher than on PD-1− MDSCs and proliferation of MDSCs in a tumor microenvironment was more strongly induced in PD-1+ MDSCs than in PD-1− MDSCs. Although we could not characterize the inducer of PD-1 expression derived from cancer cells, our findings indicate that the study on the mechanism of PD-1 induction in MDSCs is important and necessary for the control of MDSC activity; our results suggest that PD-1+ MDSCs in a tumor microenvironment may induce tumor development and relapse through the modulation of their proliferation and suppressive molecules.

An innovative anti-cancer Chinese herbal formula exhibited multi-targeted efficacies in metastatic breast cancer mouse model

BackgroundThe incidence and mortality of cancer metastasis is high worldwide. Despite of the chemotherapeutic agents, many cancer patients still take traditional Chinese herbal prescriptions as adjuvant treatments. However, most of these herbal formulae/products lack of evidence-based efficacy. Based on our previous investigations on anti-tumor, anti-angiogenic, anti-metastatic, bone protective and immunomodulating activities of various Chinese herbal medicines, four constituent herbs, namely Andrographis paniculata, Acanthopanax senticosus, Camellia sinensis, and Hedyotis diffusa were eventually selected to form an innovative herbal formula.MethodsThe anti-tumor efficacies of the formula were evaluated in metastatic breast cancer mice model. The bone protective and immunomodulatory effects were also assessed after formula treatment.ResultsOur results showed that the breast tumor weight as well as lung and liver metastasis in mice could be reduced after herbal formula treatment for 4 weeks. The breast tumor-induced osteolysis in mice was restored by herbal formula treatment, in which the bone volume in treated mice tibia was comparable to that in the non-tumor bearing normal mice. The IL-12 level was augmented and the survival of mice with metastatic breast tumors was prolonged after treatment. Furthermore, combination of herbal formula with chemotherapeutic agent doxorubicin resulted in better anti-tumor efficacy and increased life span in tumor-bearing mice, when compared with doxorubicin alone treatment.ConclusionsIn summary, our innovative Chinese herbal formula was demonstrated to possess anti-tumor, anti-metastatic and bone-protective activities in metastatic breast tumor-bearing mice. The preclinical data generated in this study would lead to the development of evidence-based supplement as adjuvant therapy for metastatic breast cancer.

Systemic infection with Candida albicans in breast tumor bearing mice: Cytokines dysregulation and induction of regulatory T cells

ObjectiveThe effect of candidemia on immunologic parameters in breast tumor bearing patients is not well studied. Here, we hypothesised that candidemia in the tumor background may change the outcome of immunologic parameters and tumor condition. MethodMice were divided into four groups, including normal, tumor, Candida infected (only Candidiasis) and tumor/Candidiasis groups. Tumor changes were recorded daily after tumor transplantation and induction of candidemia. Splenocytes of mice were harvested, cultured, and stimulated with PHA; afterwards, IL-4, IL-10, IFN-γ, TNF-α and TGF-β cytokines were assessed using ELISA kits. We also evaluated the population of CD4+CD25+Foxp3+ regulatory T cells in the tumor infiltrated and splenocytes. ResultsThe results showed that infection with C. albicans decreased the IFN-γ/IL-4 ratio in tumor/candidiasis and candidiasis groups versus their non-infected controls. IL-10, TGF-β and TNF-α levels increased in the candidiasis group. In addition, Candidemia led to an increase in the Treg population in tumor microenvironment and splenocytes of experimental groups compared with non-infected controls. Finally, candidemia increased tumor growth of tumor/Candidiasis group compared with the tumor group. ConclusionIt seems that systemic infection with C. albicans could not only induce regulatory T cells but also result in dysregulation of cytokine network and thereby facilitate tumor growth.

Image-Guided Neutron Capture Therapy Using the Gd-DO3A-BTA Complex as a New Combinatorial Treatment Approach.

Gadolinium-neutron capture therapy (Gd-NCT) is based on the nuclear capture reaction that occurs when 157Gd is irradiated with low energy thermal neutrons to primarily produce gamma photons. Herein, we investigated the effect of neutron capture therapy (NCT) using a small molecular gadolinium complex, Gd-DO3A-benzothiazole (Gd-DO3A-BTA), which could be a good candidate for use as an NCT drug due to its ability to enter the intracellular nuclei of tumor cells. Furthermore, MRI images of Gd-DO3A-BTA showed a clear signal enhancement in the tumor, and the images also played a key role in planning NCT by providing accurate information on the in vivo uptake time and duration of Gd-DO3A-BTA. We injected Gd-DO3A-BTA into MDA-MB-231 breast tumor-bearing mice and irradiated the tumors with cyclotron neutrons at the maximum accumulation time (postinjection 6 h); then, we observed the size of the growing tumor for 60 days. Gd-DO3A-BTA showed good therapeutic effects of chemo-Gd-NCT for the in vivo tumor models. Simultaneously, the Gd-DO3A-BTA groups ([Gd-DO3A-BTA(+), NCT(+)]) showed a significant reduction in tumor size (p < 0.05), and the inhibitory effect on tumor growth was exhibited in the following order: [Gd-DO3A-BTA(+), NCT(+)] > [Gd-DO3A-BTA(+), NCT(−)] > [Gd-DO3A-BTA(−), NCT(+)] > [Gd-DO3A-BTA(−), NCT(−)]. On day 60, the [Gd-DO3A-BTA(+), NCT(+)] and [Gd-DO3A-BTA(−), NCT(−)] groups exhibited an approximately 4.5-fold difference in tumor size. Immunohistochemistry studies demonstrated that new combinational therapy with chemo-Gd-NCT could treat breast cancer by both the inhibition of tumor cell proliferation and induction of apoptosis-related proteins, with in vivo tumor monitoring by MRI.

Folate receptor-targeted liposomal nanocomplex for effective synergistic photothermal-chemotherapy of breast cancer in vivo.

An effective nanoparticle-based drug delivery platform holds great promise for non-invasive cancer therapy. This study explores the breast tumor regression in vivo by synergistic photothermal-chemotherapy based on liposomal nanocomplex (folic acid-gold nanorods-anticancer drug-liposome). The proposed liposomal nanocomplex can enhance the tumor targeting by functionalizing folic acid (FA) molecules on the surface of liposome that encapsulates both gold nanorods (AuNRs) and the doxorubicin (DOX) to combine the photothermal therapy and the chemotherapy, respectively. Herein, 7-nm gold nanorods were fabricated and co-encapsulated with DOX into nanoliposomes functionalized with FA, with an average diameter of 154 nm, for active targeting to the cancer cells. The experimental results showed that the FA targeting liposomes had better cellular uptake than the non-targeting liposomes (AuNRs-DOX-LPs). Especially, upon 5 min exposure to near infrared (NIR) irradiation (808 nm) triggered DOX release could be achieved to 46.38% in 60 min at pH 5.5. In addition, in vitro cell proliferation assays indicated that, with synergistic photothermal-chemotherapy, the targeting liposomes could significantly enhance the toxicity towards the cancer cells with the IC50 value of 1.90 ± 0.12 μg mL-1. Furthermore, in vivo experiments on the breast tumor-bearing mice showed that the targeting liposomes could effectively inhibit the growth of the tumors using the combined strategy.

AS1411 aptamer-targeted gold nanoclusters effect on the enhancement of radiation therapy efficacy in breast tumor-bearing mice.

Herein, the AS1411 aptamer-targeted ultrasmall gold nanoclusters (GNCs) were assessed at different aspects as a radiosensitizer. AS1411 aptamer-conjugated gold nanoclusters (Apt-GNCs) efficacy was evaluated at cancer cells targeting, radiosensitizing effect, tumor targeting, and biocompatibility in breast tumor-bearing mice. Flow cytometry and fluorescence microscopy exhibited more cellular uptake for Apt-GNCs in comparison with GNCs. In addition, inductively coupled plasma optical emission spectrometry results demonstrated its effective tumor targeting as the tumors' gold content for GNCs and Apt-GNCs were 8.53 and 15.33μg/g, respectively. Apt-GNCs significantly enhanced radiotherapy efficacy as mean tumors' volume decreased about 39% and 9 days increase in the mice survival was observed. Both GNCs and Apt-GNCs were biocompatible. The Apt-GNCs is a novel and efficient radiosensitizer.

Abstract 3875: Lymphatically directed MAPK/PI3K/mTOR inhibitor for treatment of cancer growth and metastasis

Abstract The Ras-ERK and PI3K/mTOR signaling pathways have profound effects on cancer cell survival, differentiation, proliferation, metabolism and motility. Due to the importance of these pathways, a myriad of compounds has been developed to inhibit key signaling nodes including MEK, PI3K and PI3K/mTOR inhibitors. Evidence has shown that extensive cross-talk and compensation between pathways occurs shifting therapeutic efforts towards strategies to target multiple pathways to improve therapeutic outcomes. However, clinical trials evaluating MAPK and PI3K combination therapies have revealed poor tolerability leading to early discontinuation. Here we show a multifunctional molecular inhibitor (ST-182) capable of simultaneous inhibition of MAPK, PI3K and mTOR pathways. Kinase assays were used to determine IC50s for MEK1, PI3K α, β, δ, γ and mTOR confirming in vitro targeting of these signaling nodes. Phosphorylation changes of ERK and AKT as surrogate markers for kinase inhibition were confirmed in multiple breast cancer cell lines and determined to be independent of their BRCA1 mutational status. Reverse phase protein array performed in MDA-MB-231 cells indicated both efficient MAPK and PI3K/mTOR pathway inhibition and along with differential regulation of epithelial-mesenchymal transition (EMT) pathways compared to combination therapy of single agents (MEK plus PI3K inhibitor). Using excised breast cancer tissue from orthotopic mammary tumor mouse models (MDA-MB-231 and AT-3), ST-182 was found to modulate MEK and PI3K/mTOR activities demonstrating in vivo bioavailability confirming simultaneous multifunctional inhibition of Ras/MEK/ERK and PI3K/AKT/mTOR pathways. Innovative Kinase Translocation Reporters (KTR) were used to confirm in vitro and in vivo inhibition of these pathways. Treatment of breast tumor bearing mice daily with ST-182 (400 mg/kg, PO) achieved a significant reduction in volumetric tumor growth versus control animals with no observed systemic toxicity. Furthermore, we observed a reduction in metastatic tumor load in these mouse models underpinning its regulation of EMT proteins. Pharmacokinetics evaluation of ST-182 following oral administration revealed unique physiochemical properties promoting direct lymphatic system uptake as the primary absorption route at an astonishing &amp;gt;95% level rather than traditional portal vein absorption. Significant implications of lymph-directed uptake include circumventing first pass metabolism, enhanced bioavailability and reduction in systemic toxicities. This paradigm shift in drug development is anticipated to open up new opportunities for delivery of receptor tyrosine kinase (RTK) inhibitors using lymph-directed compounds to improve clinical outcome of breast cancer along with other tumor types. Citation Format: Stefanie Galbán, Carlos Espinoza, Kathryn E. Luker, Gary D. Luker, Marcian Van Dort, Brian D. Ross. Lymphatically directed MAPK/PI3K/mTOR inhibitor for treatment of cancer growth and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3875.

Abstract 69: Chemotherapy-induced cancer cell death diminishes therapeutic efficacy through heme oxygenase-1-mediated inactivation of M1-like tumor associated macrophages

Abstract One of the most common treatment options for cancer is a chemotherapy. After chemotherapy, however, unwanted host effects provoke tumor recurrence and aggressiveness of cancer cells, which often arise as a consequence of disruption in the patient's immune system. Lymphocytes, such as CD8+ cytotoxic T lymphocytes (CTLs), which have capability of suppressing cancer progression, are depleted following chemotherapy. Conventional chemotherapeutic agents kill cancer cells, which boosts recruitment of myeloid cells. Tumor-associated macrophages (TAMs), emerging as abundant tumor-infiltrating myeloid cells in tumor microenvironment, play an important role in immunosuppression caused by conventional chemotherapy. Chemotherapy-induced dying cancer cells could hijack accumulated TAMs, provoking tumor recurrence. Therefore, reprogramming of TAMs to maximize the chemotherapeutic efficacy is considered a promising novel anticancer strategy. In this study, we investigated whether dying cancer cells after chemotherapy could reduce therapeutic efficacy by modulating tumor-infiltrating macrophage activity. In a 4T1 syngeneic mouse breast cancer model, there was a marked decrease in the proportion of M1-like TAMs expressing CD86 with tumor-suppressive activity and reduced tumor infiltration of CTLs following treatment with paclitaxel. Paclitaxel treatment also resulted in an enhancement of heme oxygenase-1 (HO-1) mRNA levels in tumor-infiltrating myeloid cells engulfing dying cancer cells. Consistent with the in vivo profile of TAMs, bone marrow-derived macrophages (BMDMs) phagocytosing dying breast cancer cells exhibited significant upregulation of HO-1 expression. HO-1 induction in BMDMs engulfing dying breast cancer cells facilitated M2 polarization. In contrast, abrogation of HO-1 activity sustained M1 activation of BMDMs co-cultured with dying breast cancer cells. Pharmacologic inhibition of HO-1 activity with zinc protoporphyin IX augmented paclitaxel efficacy by stimulating tumor infiltration of CTLs in a 4T1 breast cancer model. Furthermore, blockade of HO-1 in breast tumor-bearing mice induced increased M1-like TAMs expressing CD86 that plays an important role in stimulating antitumor immune response. Taken together, HO-1 induction by the chemotherapy-derived dying cancer cells in TAMs dampens antitumor effects of chemotherapy by manipulating innate and adaptive immunity. Our results demonstrate that targeting overexpressed HO-1 in the breast tumor microenvironment can control the immune system to potentiate the efficacy of chemotherapy. Citation Format: Seung Hyeon Kim, Xiancai Zhong, Shin-Young Gwak, Ishrat Aklima Muna, Sin-Aye Park, Young-Nam Cha, Young-Joon Surh. Chemotherapy-induced cancer cell death diminishes therapeutic efficacy through heme oxygenase-1-mediated inactivation of M1-like tumor associated macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 69.

Anti-tumor effects of propranolol: Adjuvant activity on a transplanted murine breast cancer model

Propranolol (Pro), a non-specific β-adrenergic blocking drug, competitively prevents the binding of catecholamines to receptors and suppresses cancer cells. The anti-tumor activity of propranolol has been proved in different kinds of cancers. In this study, we assessed the adjuvant activity of propranolol combined with a tumor vaccine model on the immunological parameters of breast tumor-bearing mice. Breast tumor pieces were implanted into the flank of inbred BALB/C female mice from stock mice. Tumor-bearing mice were treated with tumor antigen lysate vaccine and propranolol/Vaccine (Pro/Vac) combination (as treatment groups), propranolol and PBS (as control groups) for 5 consecutive days, every 12 h. Moreover, all experimental groups received vaccine for three times with one-week interval via s.c injection. After immunization courses, spleens of tumor-bearing mice were removed and dissected, cell suspension was stimulated in vitro, and the cytokine levels in supernatant of splenocytes were measured via commercial ELISA kits. Compared with the vaccine group, immunization with tumor lysate in combination with propranolol significantly increased IL-2, IL-4, IL-12, IL-17, and IFN-γ cytokines. Considering the suppression of tumor growth, propranolol seems to be a potent immunomodulator capable of inducing cellular immune responses against breast cancer.

General synthesis of silica-based yolk/shell hybrid nanomaterials and in vivo tumor vasculature targeting.

Multifunctional yolk/shell-structured hybrid nanomaterials have attracted increasing interest as theranostic nanoplatforms for cancer imaging and therapy. However, because of the lack of suitable surface engineering and tumor targeting strategies, previous research has focused mainly on nanostructure design and synthesis with few successful examples showing active tumor targeting after systemic administration. In this study, we report the general synthetic strategy of chelator-free zirconium-89 (89Zr)-radiolabeled, TRC105 antibody-conjugated, silica-based yolk/shell hybrid nanoparticles for in vivo tumor vasculature targeting. Three types of inorganic nanoparticles with varying morphologies and sizes were selected as the internal cores, which were encapsulated into single hollow mesoporous silica nanoshells to form the yolk/shell-structured hybrid nanoparticles. As a proof-of-concept, we demonstrated successful surface functionalization of the nanoparticles with polyethylene glycol, TRC105 antibody (specific forCD105/endoglin), and 89Zr (a positron-emitting radioisotope), and enhanced in vivo tumor vasculature-targeted positron emission tomography imaging in 4T1murine breast tumor-bearing mice. This strategy could be applied to the synthesis of other types of yolk/shell theranostic nanoparticles for tumor-targeted imaging and drug delivery.

Tracking the fate of adoptively transferred myeloid-derived suppressor cells in the primary breast tumor microenvironment.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid progenitor cells that are expanded in cancer and act as potent suppressors of the anti-tumor immune response. MDSCs consist of two major subsets, namely monocytic (M-) MDSCs and granulocytic (G-) MDSCs that differ with respect to their phenotype, morphology and mechanisms of suppression. Here, we cultured bone marrow cells with IL-6 and GM-CSF in vitro to generate a population of bone marrow MDSCs (BM-MDSCs) similar to G-MDSCs from tumor-bearing mice in regards to phenotype, morphology and suppressive-function. Through fluorescent labeling of these BM-MDSCs and optical imaging, we could visualize the recruitment and localization of BM-MDSCs in breast tumor-bearing mice in vivo. Furthermore, we were able to demonstrate that BM-MDSCs home to primary and metastatic breast tumors, but have no significant effect on tumor growth or progression. Ex vivo flow cytometry characterization of BM-MDSCs after adoptive transfer demonstrated both organ-and tumor-specific effects on their phenotype and differentiation, demonstrating the importance of the local microenvironment on MDSC fate and function. In this study, we have developed a method to generate, visualize and detect BM-MDSCs in vivo and ex vivo through optical imaging and flow cytometry, in order to understand the organ-specific changes rendered to MDSCs in breast cancer.

Stress alleviation strategy in cancer treatment: Insights from a mathematical model

AbstractTumors generate mechanical forces during growth and progression, which are able to compress blood and lymphatic vessels, reducing perfusion rates and creating hypoxia. Tumor vessels—while nourishing the tumor—are usually leaky and tortuous, which further decreases perfusion. Consequently, vessel leakiness together with vessel compression causes a uniformly elevated interstitial fluid pressure that hinder drug delivery and compromise therapeutic outcomes. To enhance treatment efficacy, stress alleviation and vascular normalization strategies have been developed to improve tumor perfusion and drug delivery. Stress alleviation strategy aim to decrease solid stress levels and reopen compressed blood vessels leading to improve perfusion and drug delivery. On the other hand, vascular normalization strategy aims to restore the abnormalities in tumor vasculature by decreasing vessel leakiness and thus enhance drug efficacy. Here, we employed a mathematical model to study the stress alleviation strategy using published experimental data and performing new experiments in mice bearing breast tumors. Specifically, we accounted for variations in tumor hydraulic conductivity, elastic modulus and swelling related to changes in extracellular matrix components induced by the anti‐fibrotic and stress alleviating drug, tranilast. We showed that alleviation of mechanical stresses in tumors reduces the tumor interstitial fluid pressure to normal levels and increases the functionality of the tumor vasculature resulted in improved drug delivery and treatment outcome. Finally, we used model predictions to show that vascular normalization can be combined with stress alleviation to further improve therapeutic outcomes.

Influence of BCYRN1 on Proliferation and Migration of Breast Cancer Cell Line MCF7 and Tumor-bearing Mice

Influence of BCYRN1 on Proliferation and Migration of Breast Cancer Cell Line MCF7 and Tumor-bearing Mice

Optimizing the dosing schedule of l-asparaginase improves its anti-tumor activity in breast tumor-bearing mice

Proliferation of acute lymphoblastic leukemic cells is nutritionally dependent on the external supply of asparagine. l-asparaginase, an enzyme hydrolyzing l-asparagine in blood, is used for treatment of acute lymphoblastic leukemic and other related blood cancers. Although previous studies demonstrated that l-asparaginase suppresses the proliferation of cultured solid tumor cells, it remains unclear whether this enzyme prevents the growth of solid tumors in vivo. In this study, we demonstrated the importance of optimizing dosing schedules for the anti-tumor activity of l-asparaginase in 4T1 breast tumor-bearing mice. Cultures of several types of murine solid tumor cells were dependent on the external supply of asparagine. Among them, we selected murine 4T1 breast cancer cells and implanted them into BALB/c female mice kept under standardized light/dark cycle conditions. The growth of 4T1 tumor cells implanted in mice was significantly suppressed by intravenous administration of l-asparaginase during the light phase, whereas its administration during the dark phase failed to show significant anti-tumor activity. Decreases in plasma asparagine levels due to the administration of l-asparaginase were closely related to the dosing time-dependency of its anti-tumor effects. These results suggest that the anti-tumor efficacy of l-asparaginase in breast tumor-bearing mice is improved by optimizing the dosing schedule.

Detection of lymph node metastasis using photoacoustic imaging and glycol-chitosan-coated gold nanoparticles

Metastases, rather than primary tumors, are responsible for majority of deaths in cancer patients. We developed a non-invasive method to detect sentinel lymph node (SLN) metastasis using combined ultrasound and photoacoustic (US/PA) imaging with glycol-chitosan-coated gold nanoparticles (GC-AuNP). The spatio-temporal distribution of GC-AuNP is affected by presence of metastasis, which is detected by US/PA. GC-AuNPs (100 μl, 0.1 mg Au/ml) were injected peritumorally in breast tumor-bearing mice, and allowed to drain for 24 hours into the SLN. The SLN was located using b-mode ultrasound, and multi-wavelength PA was used to detect GC-AuNPs. Spectroscopic analysis allowed to isolate the signal from GC-AuNPs and quantify their accumulation in the SLN after cellular uptake and transport by immune cells. Results show that distribution of GC-AuNPs in the SLN was affected by presence of metastasis. The overall accumulation was also reduced, with more than 20% signal decrease compared to non-metastatic controls. Histological analysis confirmed that distribution of GC-AuNP-containing immune cells is reduced due to presence of metastatic cells. Our method successfully distinguishes metastatic from non-metastatic lymph nodes using biocompatible nanoparticles and could aid physicians in detection of micrometastasis thus guiding and avoiding unnecessary SLN biopsy.