Low-dose Doxorubicin Research Articles

SCIDOT-43. FINAL DATA ANALYSIS OF A PILOT STUDY TESTING THE EFFICACY OF USING LASER INTERSTITIAL THERMAL THERAPY (LITT) TO INDUCE TEMPORARY DISRUPTION OF THE PERITUMORAL BLOOD BRAIN BARRIER (BBB) TO IMPROVE EFFECTIVENESS OF BBB-IMPERMEANT CHEMOTHERAPY IN RECURRENT GLIOBLASTOMA

Abstract BACKGROUND Poor CNS drug delivery is a major limiting factor in GBM therapy. Since most recurrences occur peritumorally where infiltrating glioma cells reside, peritumoral BBB disruption may help improve drug delivery and efficacy. LITT, a minimally invasive cytoreductive treatment for brain tumors, may disrupt BBB as evidenced by post-ablation contrast enhancement. METHODS Patients with recurrent GBM were treated with LITT. The degree of post-LITT peritumoral BBB disruption was measured by the vascular transfer constant (Ktrans) in brain DCE-MRI. Serum levels of brain-specific enolase (BSE) were quantified as an independent measure of BBB disruption. Forty enrollments were planned with equal randomization to weekly low-dose doxorubicin, a BBB-impermeant chemotherapy, either during the BBB-permeable window (Early Dox) or after the resolution of disruption (Late Dox). The primary endpoint is 6-month PFS rate (6-PFS). RESULTS Peritumoral Ktrans peaked immediately post LITT, followed by a gradual decline for the next 4 weeks. Similarly, serum BSE concentrations peaked in 1–3 weeks after LITT before decreasing to baseline by 6 weeks. 41 patients were randomized to Early and Late Dox. 31 patients (14 Early and 17 Late Dox) were evaluable for the primary endpoint. MGMT promoter methylation rate was 28% and 47% in the Early and Late Dox arms, respectively. 6-PFS was 57.1% (8/14) in Early Dox compared to 35.3% (6/17) in Late Dox. PFS was 5.8 (95%CI: 4.1–6.3) months vs. 4.9 (95%CI: 2.4–6.3) months, while OS was 12.8 (95%CI: 7.8–14.5) months vs. 13.6 (95%CI: 10.2–17.1) months, for Early vs. Late Dox, respectively. The most common grade 3–4 toxicities were cytopenia observed in 6 (16%) patients. CONCLUSIONS LITT induces temporary peritumoral BBB disruption lasting 4–6 weeks, providing a rare opportunity to enhance local delivery of potentially efficacious but BBB-impermeant therapeutic agents. 6-PFS strongly favors dox given early during the window of BBB disruption, thus supporting the hypothesis.

Cancer-Cell-Membrane-Coated Nanoparticles with a Yolk-Shell Structure Augment Cancer Chemotherapy.

Despite rapid advancements in antitumor drug delivery, insufficient intracellular transport and subcellular drug accumulation are still issues to be addressed. Cancer cell membrane (CCM)-camouflaged nanoparticles (NPs) have shown promising potential in tumor therapy due to their immune escape and homotypic binding capacities. However, their efficacy is still limited due to inefficient tumor penetration and compromised intracellular transportation. Herein, a yolk-shell NP with a mesoporous silica nanoparticle (MSN)-supported PEGylated liposome yolk and CCM coating, CCM@LM, was developed for chemotherapy and exhibited a homologous tumor-targeting effect. The yolk-shell structure endowed CCM@LM with moderate rigidity, which might contribute to the frequent transformation into an ellipsoidal shape during infiltration, leading to facilitated penetration throughout multicellular spheroids in vitro (up to a 23.3-fold increase compared to the penetration of membrane vesicles). CCM@LM also exhibited a cellular invasion profile mimicking an enveloped virus invasion profile. CCM@LM was directly internalized by membrane fusion, and the PEGylated yolk (LM) was subsequently released into the cytosol, indicating the execution of an internalization pathway similar to that of an enveloped virus. The incoming PEGylated LM further underwent efficient trafficking throughout the cytoskeletal filament network, leading to enhanced perinuclear aggregation. Ultimately, CCM@LM, which co-encapsulated low-dose doxorubicin and the poly(ADP-ribose) polymerase inhibitor, mefuparib hydrochloride, exhibited a significantly stronger antitumor effect than the first-line chemotherapeutic drug Doxil. Our findings highlight that NPs that can undergo facilitated tumor penetration and robust intracellular trafficking have a promising future in cancer chemotherapy.

Reprogramming the T cell response to cancer by simultaneous, nanoparticle-mediated PD-L1 inhibition and immunogenic cell death

In this study, dual drug-loaded nanoparticles were constructed to co-deliver low-dose doxorubicin (DOX) and miR-200c (DOX/miR-NPs) to inhibit programmed death-1 receptor (PD-L1) expression and trigger immunogenic cell death (ICD) in cancer cells. Two block copolymers, folic acid (FA)-conjugated PLGA-PEG (PLGA-PEG-FA) and PLGA-PEI, were formulated as folate-targeted NPs and loaded with DOX and miR-200c. The NPs, which were formed as nanosize objects (110.4 ± 2.1) with narrow size distribution (0.19 ± 0.02), effectively protected the miR-200c from degradation in serum. Modifying the NPs with FA increased not only their uptake by cancer cells in vitro but also their accumulation in tumor microenvironments in vivo, as compared with those properties of non-FA-modified NPs. The DOX/miR-NPs also exhibited efficacious inhibition of PD-L1 expression and robust induction of ICD in cancer cells in vitro and in vivo, resulting in increased dendritic cell maturation and CD8+ T cell response towards cancer cells. Furthermore, tumor growth was significantly inhibited by folate-targeted NPs loaded with the low-dose DOX/miR-200c combination, but not by treatments with free DOX, miR-NPs or DOX-NPs. Thus, our results suggest that simultaneous PD-L1 inhibition via microRNAs and the induction of an immunogenic tumor microenvironment via low-dose cytotoxic drugs may improve cancer therapy efficacy.

P6305Activation of invariant natural killer T cells ameliorates doxorubicin-induced cardiomyopathy

Abstract Background Invariant natural killer T (iNKT) cells orchestrate tissue inflammation via regulating various cytokine productions, especially strongly upregulating interferon (IFN)-γ. Activation of iNKT cells have been previously reported to exert protective effects against post-infarcted cardiac remodeling and cardiac ischemia/reperfusion injury. However, the role of iNKT cells has not been determined in doxorubicin (DOX)-induced cardiomyopathy. Purpose The purpose of this study was to examine whether the activation of iNKT cells by α-galactosylceramide (αGC), which specifically activates iNKT cells, could affect DOX-induced cardiomyopathy, and if so, to elucidate its downstream target. Methods C57BL/6J mice were received the intraperitoneal injection of either αGC (0.1μg/g, n=11) or vehicle (n=13). After 1 week, these mice were treated with a low dose of DOX (18mg/kg via intravenous 3 injections over 1 week), and were followed during 14 days. Results DOX mice (DOX+vehicle) showed left ventricular (LV) dysfunction and dilatation, which were significantly ameliorated in DOX mice receiving αGC (DOX+αGC) (LV fractional shortening: 27.4±4.31 vs. 31.5±4.62%, p<0.05, LV end-diastolic diameter: 3.70±0.16 vs. 3.32±0.23mm, p<0.05), with no significant changes in arterial pressure, body weight, and food consumption, 14 days after DOX injection. DOX+vehicle demonstrated a significant decrease in myocardial gene expression of Vα14Jα18, a specific marker of iNKT cells, and IFN-γ compared with control mice. Vα14Jα18 expression levels were higher in DOX+αGC than DOX+vehicle by 9.2 folds (p<0.05). Consistent with this change, IFN-γ was higher in DOX+αGC than DOX+vehicle by 4.4 folds (p<0.05), whereas interleukin (IL)-1, IL-4, IL-6, IL-10, IL-17, IL-23, and tumor necrosis factor (TNF)-α were not altered in both groups. Phosphorylation of Akt, its active form, in the heart was significantly increased in DOX+αGC compared with DOX+vehicle by 1.8 folds (p<0.05). Conclusions Activation of iNKT cells by αGC play a protective role against DOX-induced cardiac dysfunction, which was associated with enhancing expression of IFN-γ and activating Akt. Therapies designed to activate iNKT cells might be beneficial to protect the heart from DOX injury.

P53 prevents doxorubicin cardiotoxicity independently of its prototypical tumor suppressor activities

Doxorubicin is a widely used chemotherapeutic agent that causes dose-dependent cardiotoxicity in a subset of treated patients, but the genetic determinants of this susceptibility are poorly understood. Here, we report that a noncanonical tumor suppressor activity of p53 prevents cardiac dysfunction in a mouse model induced by doxorubicin administered in divided low doses as in the clinics. While relatively preserved in wild-type (p53 +/+ ) state, mice deficient in p53 (p53 -/- ) developed left ventricular (LV) systolic dysfunction after doxorubicin treatment. This functional decline in p53 -/- mice was associated with decreases in cardiac oxidative metabolism, mitochondrial mass, and mitochondrial genomic DNA (mtDNA) homeostasis. Notably, mice with homozygous knockin of the p53 R172H (p53 172H/H ) mutation, which like p53 -/- state lacks the prototypical tumor suppressor activities of p53 such as apoptosis but retains its mitochondrial biogenesis capacity, showed preservation of LV function and mitochondria after doxorubicin treatment. In contrast to p53-null state, wild-type and mutant p53 displayed distinct mechanisms of transactivating mitochondrial transcription factor A (TFAM) and p53-inducible ribonucleotide reductase 2 (p53R2), which are involved in mtDNA transcription and maintenance. Importantly, supplementing mice with a precursor of NAD+ prevented the mtDNA depletion and cardiac dysfunction. These findings suggest that loss of mtDNA contributes to cardiomyopathy pathogenesis induced by doxorubicin administered on a schedule simulating that in the clinics. Given a similar mtDNA protection role of p53 in doxorubicin-treated human induced pluripotent stem cell (iPSC)-derived cardiomyocytes, the mitochondrial markers associated with cardiomyopathy development observed in blood and skeletal muscle cells may have prognostic utility.

Prokineticin Receptor-1 Signaling Inhibits Dose- and Time-Dependent Anthracycline-Induced Cardiovascular Toxicity Via Myocardial and Vascular Protection

ObjectivesThis study investigated how different concentrations of doxorubicin (DOX) can affect the function of cardiac cells. This study also examined whether activation of prokineticin receptor (PKR)-1 by a nonpeptide agonist, IS20, prevents DOX-induced cardiovascular toxicity in mouse models. BackgroundHigh prevalence of heart failure during and following cancer treatments remains a subject of intense research and therapeutic interest. MethodsThis study used cultured cardiomyocytes, endothelial cells (ECs), and epicardium-derived progenitor cells (EDPCs) for in vitro assays, tumor-bearing models, and acute and chronic toxicity mouse models for in vivo assays. ResultsBrief exposure to cardiomyocytes with high-dose DOX increased the accumulation of reactive oxygen species (ROS) by inhibiting a detoxification mechanism via stabilization of cytoplasmic nuclear factor, erythroid 2. Prolonged exposure to medium-dose DOX induced apoptosis in cardiomyocytes, ECs, and EDPCs. However, low-dose DOX promoted functional defects without inducing apoptosis in EDPCs and ECs. IS20 alleviated detrimental effects of DOX in cardiac cells by activating the serin threonin protein kinase B (Akt) or mitogen-activated protein kinase pathways. Genetic or pharmacological inactivation of PKR1 subdues these effects of IS20. In a chronic mouse model of DOX cardiotoxicity, IS20 normalized an elevated serum marker of cardiotoxicity and vascular and EDPC deficits, attenuated apoptosis and fibrosis, and improved the survival rate and cardiac function. IS20 did not interfere with the cytotoxicity or antitumor effects of DOX in breast cancer lines or in a mouse model of breast cancer, but it did attenuate the decreases in left ventricular diastolic volume induced by acute DOX treatment. ConclusionsThis study identified the molecular and cellular signature of dose-dependent, DOX-mediated cardiotoxicity and provided evidence that PKR-1 is a promising target to combat cardiotoxicity of cancer treatments.

Transcription-independent and -dependent p53-mediated apoptosis in response to genotoxic and non-genotoxic stress

We previously reported that p53-mediated apoptosis is determined by severity of DNA damage, not by the level of p53, in doxorubicin-treated prostate cancer cells. In addition to doxorubicin, our results here indicated that camptothecin and bortezomib, which are a topoisomerase 1 poison and a 26 S proteasome inhibitor, respectively, could also induce apoptosis in a p53-dependent manner in prostate cancer. Then, we examined whether p53-mediated apoptosis induced by genotoxic and non-genotoxic stress occur in the same or a different way. By using dominant negative p53 to compete with wild-type p53 in transcription activity, we demonstrated that p53-mediated apoptosis in response to doxorubicin- or camptothecin-induced genotoxic stress is transcription-independent. In contrast, p53-mediated apoptosis from bortezomib-induced stress is transcription-dependent. Interestingly, we also found that doxorubicin-induced p21 expression is activated by p53 in transcription-dependent manner, while camptothecin-induced p21 expression is p53-independent. We then investigated the p53 ratio of nucleus to cytosol corresponding to low and high dose doxorubicin, camptothecin, or bortezomib treatment. The results suggested that p53 translocation from cytoplasm to nucleus actively drives cells toward apoptosis in either transcription-dependent or -independent manner for responding to non-genotoxic or genotoxic stress, respectively.

Mechanisms of doxorubicin-induced drug resistance and drug resistant tumour growth in a murine breast tumour model

BackgroundDoxorubicin is currently the most effective chemotherapeutic drug used to treat breast cancer. It has, however, been shown that doxorubicin can induce drug resistance resulting in poor patient prognosis and survival. Studies reported that the interaction between signalling pathways can promote drug resistance through the induction of proliferation, cell cycle progression and prevention of apoptosis. The aim of this study was therefore to determine the effects of doxorubicin on apoptosis signalling, autophagy, the mitogen-activated protein kinase (MAPK)- and phosphoinositide 3-kinase (PI3K)/Akt signalling pathway, cell cycle control, and regulators of the epithelial-mesenchymal transition (EMT) process in murine breast cancer tumours.MethodsA tumour-bearing mouse model was established by injecting murine E0771 breast cancer cells, suspended in Hank’s Balances Salt Solution and Corning® Matrigel® Basement Membrane Matrix, into female C57BL/6 mice. Fourty-seven mice were randomly divided into three groups, namely tumour control (received Hank’s Balances Salt Solution), low dose doxorubicin (received total of 6 mg/ml doxorubicin) and high dose doxorubicin (received total of 15 mg/ml doxorubicin) groups. A higher tumour growth rate was, however, observed in doxorubicin-treated mice compared to the untreated controls. We therefore compared the expression levels of markers involved in cell death and survival signalling pathways, by means of western blotting and fluorescence-based immunohistochemistry.ResultsDoxorubicin failed to induce cell death, by means of apoptosis or autophagy, and cell cycle arrest, indicating the occurrence of drug resistance and uncontrolled proliferation. Activation of the MAPK/ extracellular-signal-regulated kinase (ERK) pathway contributed to the resistance observed in treated mice, while no significant changes were found with the PI3K/Akt pathway and other MAPK pathways. Significant changes were also observed in cell cycle p21 and DNA replication minichromosome maintenance 2 proteins. No significant changes in EMT markers were observed after doxorubicin treatment.ConclusionsOur results suggest that doxorubicin-induced drug resistance and tumour growth can occur through the adaptive role of the MAPK/ERK pathway in an effort to protect tumour cells. Previous studies have shown that the efficacy of doxorubicin can be improved by inhibition of the ERK signalling pathway and thereby treatment failure can be overcome.

Ultrastructural Changes and Antitumor Effects of Doxorubicin/Thymoquinone-Loaded CaCO3 Nanoparticles on Breast Cancer Cell Line.

Background: Combination chemotherapy of anticancer drugs is extensively being researched since it could reduce multidrug resistance and side effects as a result of lower dosage of each drug. In this study, we evaluated the effects of doxorubicin-loaded (Dox-ACNP), thymoquinone-loaded (TQ-ACNP) and a combined doxorubicin/thymoquinone-loaded cockle shell-derived aragonite calcium carbonate nanoparticles (Dox/TQ-ACNP) on breast cancer cell line and compared with their free drugs counterpart.Methods: Cell viability using MTT assay, apoptosis with Annexin V-PI kit, morphological changes using contrast light microscope, scanning electron microscope and transmission electron microscope, cell cycle analysis, invasion assay, and scratch assay were carried out. The cell viability was evaluated in breast cancer cell line (MDA MB231), normal breast cells (MDF10A) and normal fibroblast (3T3).Results: MDA MB231 IC50 dosages of drug-loaded nanoparticle were not toxic to the normal cells. The combination therapy showed enhanced apoptosis, reduction in cellular migration and invasion when compared to the single drug-loaded nanoparticle and the free drugs. Scanning electron microscope showed presence of cell shrinkage, cell membrane blebbing, while transmission electron microscope showed nuclear fragmentation, disruption of cell membrane, apoptotic bodies, and disruption of mitochondrial cistern.Conclusion: The results from this study showed that the combined drug-loaded cockle shell-derived aragonite calcium carbonate nanoparticles (Dox/TQ-ACNP) showed higher efficacy in breast cancer cells at lower dose of doxorubicin and thymoquinone.

Abstract 4440: Genetic knockdown of the E3 ubiquitin ligase Itch increases pancreatic cell line sensitivity to cancer therapeutics: A comparison between different gene editing techniques

Abstract Introduction: E3 ligases are responsible for tagging ubiquitin onto substrates to either activate, relocate or target the substrate for degradation via the proteasome. Previous studies have shown that genetic knockdown of the E3 ubiquitin ligase Itch caused an increase in sensitivity to gemcitabine in pancreatic cancer models both in-vitro (cell lines) and in-vivo (mouse xenografts). Here we test the hypothesis that Itch knockdown sensitises pancreatic cell lines to existing cancer therapeutics, using both transient and stable knockdown methods. Experimental Procedures: Knockdown of Itch in MiaPaCa2 (p53 mutant) and Capan 2 (p53 WT) cells was performed using both siRNA and CRISPR-Cas9 techniques; validated by western blot and RT-PCR. Alongside parental and scrambled controls, cells were treated with either doxorubicin, gemcitabine or γ-radiation. For doxorubicin and gemcitabine treatment, cells were exposed to the drug for 24 hours before it was removed. In the case of irradiation; cells were subject to 0-4Gy of radiation before being passaged onto plates. Cell viability was assessed in 96-well plates using a combination of a Sulforhodamine B assay (SRB) to quantify live cells 4 days post-treatment, and automated cytometry analysis (Celigo) to assess well confluence over each of the 4 days. Clonogenicity was also assessed by aliquoting cells at low initial density and treating the cells with distinct doses dependent on mode of treatment and cell line. After 7 days number of colonies using a colony formation algorithm on Celigo. Data Summary: Transient knockdown of Itch in p53-/- cells was sufficient to decrease cell viability. This decrease in cell viability was further potentiated by the application of gemcitabine, doxorubicin or radiation. Stable knockdown using CRISPR-Cas9 increased MiaPaCa2 cell sensitivity to low-dose doxorubicin and radiation (5-10nM and 0.5-1Gy respectively). Whilst statistically significant, the change in response was not as large as that observed with the transient knockdown. In p53 WT cells there was no significant difference in cell sensitivity upon Itch knockdown. Conclusions: The data from this investigation support the hypothesis of Itch being a possible target for sensitising pancreatic cell lines to cancer therapeutics. However the discrepancies in response to treatment between the transient and stable Itch knockdown scenarios raises the possibility that, in the case of the stable knockdown, the cells have adapted to the absence of Itch. This presents a potential weakness in using CRISPR-Cas9 in long-term experiments where the downstream consequences of gene silencing are not immediate. Citation Format: Oliver J. Read, David J. Harrison, Paul A. Reynolds. Genetic knockdown of the E3 ubiquitin ligase Itch increases pancreatic cell line sensitivity to cancer therapeutics: A comparison between different gene editing techniques [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4440.

Effects of BCc1 nanoparticle and its mixture with doxorubicin on survival of murine 4T1 tumor model.

Background: Our previous findings showed that BCc1, a nanoparticle designed based on nanochelating technology, can be considered a new anti-cancer nanoparticle if confirmed by complementary studies.Goal: In the present study, we investigated the effects of the BCc1 nanoparticle alone on some gene expressions influencing the apoptosis pathway, and also the effect of the mixture of BCc1 nanoparticle and doxorubicin on survival.Method: Using an in vitro study, the effects of the BCc1 nanoparticle on Bax, Bcl2, p53, Caspase7 and p21 gene expressions were assessed after a 24-h treatment using real-time PCR in MCF-7 and MEFs; in addition, using an in vivo study, 4T1 tumor-bearing female Balb/c mice were treated with different doses of the BCc1 nanoparticle and doxorubicin alone and together and then their mean and median survival was evaluated.Result: The results showed that the BCc1 nanoparticle increased gene expressions of RB, p53, Caspase7, p21, and Bax and decreased gene expressions of Bcl2 in MCF-7 significantly, but no change was observed in MEFs expressions. The findings revealed that the BCc1 nanoparticle, when used orally, had the highest mean and median survival time. A mixture of a high dose of the BCc1 nanoparticle (1 mg/kg) and a low dose of doxorubicin (0.1 mg/kg) showed synergistic effects on enhanced life span, while doxorubicin dose was prescribed approximately 50 times less than the murine applicable dose (5 mg/kg).Conclusion: Our results demonstrated that the BCc1 nanoparticle not only has the potential to become a novel nanomedicine for cancer therapy, but it can also provide the basis of a new medicine for cancer management when mixed with a lower applicable dose of doxorubicin.

Comparison of the Efficacy of Two Microsphere Embolic Agents for Transcatheter Arterial Chemoembolization in Hepatocellular Carcinoma Patients.

PurposeTransarterial chemoembolization (TACE) delivers cytotoxic drugs intra-arterially and induces ischemic necrosis by arterial embolization. Embolization is achieved using a variety of agents that differ widely in particle size and range, deformation, and in vivo arterial distribution. The clinical significance of these differences has not been thoroughly characterized. The present study is to compare the efficacy of Embosphere and Embozene microspheres in TACE therapy for hepatocellular carcinoma.Materials and MethodsThis retrospective study includes 108 hepatocellular carcinoma (HCC) patients who received TACE/doxorubicin with Embozene (70 patients) or Embosphere (38 patients) at a single medical center. Patient outcomes, including liver function, tumor size, tumor response, and complications after treatment, were analyzed. The change in total target lesion size and tumor response was evaluated according to embolization agent and clinical characteristics.ResultsThe postoperative glutamate oxaloacetate transaminase (mean, 194.5 vs. 147.5; p=0.032) and bilirubin (mean, 1.11 mg/dL vs. 0.73 mg/dL; p=0.016) were higher among patients treated with Embozene, the decrease in the number (55.86±25.55% vs. 41.81±38.51%, p=0.027) and size (56.37±25.91 mm vs. 43.44±37.89 mm, p=0.001) of liver tumors relative to baseline was greater in these patients than in those treated with Embosphere. These greater antitumor effects were achieved using lower doses of doxorubicin than for treatment with Embozene. Minor complications were more common among patients treated with Embosphere than with Embozene.ConclusionThese results suggest that Embozene is more efficacious than Embosphere for HCC treatment using TACE/doxorubicin.

In Situ Dendritic Cell Vaccine for Effective Cancer Immunotherapy

A cancer vaccine is an important form of immunotherapy. Given their effectiveness for antigen processing and presentation, dendritic cells (DCs) have been exploited in the development of a therapeutic vaccine. Herein, a versatile polymersomal nanoformulation that enables generation of tumor-associated antigens (TAAs) and simultaneously serves as adjuvant for an in situ DC vaccine is reported. The chimeric cross-linked polymersome (CCPS) is acquired from self-assembly of a triblock copolymer, polyethylene glycol-poly(methyl methyacrylate- co-2-amino ethyl methacrylate (thiol/amine))-poly 2-(dimethylamino)ethyl methacrylate (PEG-P(MMA- co-AEMA (SH/NH2)-PDMA). CCPS can encapsulate low-dose doxorubicin hydrochloride (DOX) to induce immunogenic cell death (ICD) and 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH), a photosensitizer to facilitate photodynamic therapy (PDT) for reactive oxygen species (ROS) generation. This combination is able to enhance the population of TAAs and DC recruitment, eliciting an immune response cascade. In addition, CCPS with primary and tertiary amines act as adjuvant, both of which can stimulate DCs recruited to form an in situ DC vaccine after combination with TAAs for MC38 colorectal cancer treatment. In vivo results indicate that the all-in-one polymersomal nanoformulation (CCPS/HPPH/DOX) increases mature DCs in tumor-draining lymph nodes (tdLNs) and CD8+ T cells in tumor tissues to inhibit primary and distant MC38 tumor growth following a single intravenous injection with a low dose of DOX and HPPH.

Cascade therapy with doxorubicin and survivin-targeted tailored nanoparticles: An effective alternative for sensitization of cancer cells to chemotherapy

Chemotherapy frequently involves combination treatment protocols to maximize tumor cell killing. Unfortunately these intensive chemotherapeutic regimes, often show disappointing results due to the development of drug resistance and higher nonspecific toxicity on normal tissues. In cancer treatment, it is critically important to minimize toxicity while preserving efficacy. We have previously addressed this issue and proposed a nanoparticle-based combination therapy involving both a molecularly targeted therapy and chemotherapeutic agent for neutralizing antiapoptotic survivin (BIRC5) to potentiate the efficacy of doxorubicin (DOX). Although the particles exhibited strong anticancer effect on the lung carcinoma A549 and the cervical carcinoma HeLa cells, there were lower-level therapeutic outcomes on the colon carcinoma HCT-116, the leukemia Jurkat and the pancreatic carcinoma MIA PaCa-2 cells. Since targeted therapies are one of the key approaches for overcoming drug resistance, tailoring the treatment of cancer cells with distinct characteristics is necessary to improve the therapeutic outcome of cancer therapy and to minimize potential pharmacokinetic interactions of drugs. In the light of this issue, this study examined whether a cascade therapy with low-dose DOX and survivin-targeted tailored nanoparticles is more effective at sensitizing HCT-116, Jurkat and MIA PaCa-2 cancer cells to DOX-chemotherapy than simultaneous combination therapy. The results demonstrated that the sequential therapy with the protocol comprising addition of the nanoparticles after incubation of cells with DOX clearly advanced the therapeutic outcome of related cancer cells, whereas the reverse protocol resulted in a reduction or delay in apoptosis, emphasizing the critical importance of formulating synergistic drug combinations in cancer therapy.

Disruption of the Rbm38-eIF4E Complex with a Synthetic Peptide Pep8 Increases p53 Expression.

Rbm38 is a p53 target and an RNA-binding protein known to suppress p53 translation by preventing eukaryotic translation initiation factor 4E (eIF4E) from binding to p53 mRNA. In this study, we show that synthetic peptides corresponding to the binding interface between Rbm38 and eIF4E, including an 8 amino acid peptide (Pep8) derived from Rbm38, are effective in relieving Rbm38-mediated repression of p53. Molecular simulations showed that Ser-6 in Pep8 forms a hydrogen bond with Asp-202 in eIF4E. Substitution of Ser-6 with Lys, but not with Asp, enhanced the ability of Pep8 to inhibit the Rbm38-eIF4E complex. Importantly, Pep8 alone or together with a low dose of doxorubicin potently induced p53 expression and suppressed colony and tumor sphere formation and xenograft tumors in Rbm38- and p53-dependent manners. Together, we conclude that modulating the Rbm38-eIF4E complex may be explored as a therapeutic strategy for cancers that carry wild-type p53. SIGNIFICANCE: Disruption of the Rbm38-eIF4E complex via synthetic peptides induces wild-type p53 expression, suppresses tumor growth and progression, and may serve as a novel cancer therapeutic strategy.

Abstract A135: Combining low-dose chemotherapy with an NK cell-based immunotherapy as a treatment for triple-negative breast cancer

Abstract In addition to being less toxic and having a lower impact on a patient’s quality of life, evidence suggests that low-dose or metronomic chemotherapy modulates adaptive and innate antitumor immune responses. In this study, we examined whether the treatment of breast cancer cells and animals bearing breast cancer cell-derived tumors with low, nontoxic doses of chemotherapies promotes sensitivity to natural killer (NK) cells, based on target cell killing in vitro and the control of tumor growth and metastasis in vivo. We have developed a low-dose doxorubicin treatment protocol that sensitizes triple-negative breast cancer (TNBC) cells (MDA-MB-231, MDA-MB-468) to killing by NK cells. Specifically, low-dose doxorubicin treatment induced a “senescent-like” state in breast cancer cells concomitant with an impaired proliferative capacity, as shown by a decreased expression of Ki-67. Treatment of breast cancer cells also upregulated their expression of ligands for activatory NK cell receptors (e.g., MICA/B, ULBP1, ULBP2, ULBP3) and markedly increased their sensitivity to lysis by donor-derived, primary NK cells and the NK-92 cell line, as assessed using an in vitro flow cytometry-based assay. The cytotoxicity of donor-derived NK cells was markedly increased by prior stimulation with IL-2. The therapeutic potential of low-dose chemotherapy alone and in combination with adoptively transferred resting and activated NK cells was evaluated using immunodeficient NSG mice bearing MDA-MB-231/RFP/LUC-derived human TNBC xenografts. Although low-dose doxorubicin treatment alone reduced the growth of the primary tumors, as assessed using caliper measurements and in vivo imaging, the growth of the primary tumor was more markedly reduced following the adoptive transfer of healthy-donor derived NK cells (mean tumor volume: 70.56mm3 versus 228.8mm3 in control groups at day 49). Importantly, although treatment with low-dose doxorubicin alone also delayed the onset of metastasis by 7 days (day 49 in control animals, day 56 in treated animals), no signs of metastasis were observed in healthy-donor derived NK cell-treated animals at the time of culling on day 50. The expression of MICA/B was 8.5 times greater on tumor cells derived from mice that received the combination treatment (p=0.0001) and these cells were more sensitive to killing by NK-92 cells in vitro (3-fold increase at E:T 1:5). Furthermore, in vitro studies demonstrating that the treatment of MDA-MB-231 cells with low-dose doxorubicin reduces the number of CD44High/CD24−/low/EpCAM+ Cancer Initiating Cells (CICs) were confirmed by there being a significantly lower number of CICs in tumors derived from treated mice. These novel findings indicate that this approach has the capacity of preventing the primary tumor “fueling” the dissemination of aggressive, metastatic disease. Taken together, these studies demonstrate that the treatment of breast cancer with low, nontoxic doses of chemotherapies promotes their sensitivity to killing by NK cells in vitro and in vivo. We have shown that administering human NK cells to mice bearing human breast tumors that have been treated with low-dose doxorubicin reduces the growth and metastasis of tumors and eliminates the aggressive cells that “feed” this process. Ongoing studies are further interrogating the influence of this approach on breast cancer metastasis. In summary, this strategy offers a promising opportunity for more effectively treating patients with aggressive, triple-negative breast cancer. Citation Format: Sarra Idri, Graham Pawelec, Yvonne Barnett, Graham Pockley. Combining low-dose chemotherapy with an NK cell-based immunotherapy as a treatment for triple-negative breast cancer [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A135.

Dendritic cell vaccination plus low-dose doxorubicin for the treatment of spontaneous canine hemangiosarcoma

Angiosarcoma is a deadly neoplasm of the vascular endothelium. Metastatic disease is often present at diagnosis, and 5-year survival is only 10–35%. Although there exist no immunocompetent mouse models of angiosarcoma with which to study immune-based approaches to therapy, angiosarcoma is a major killer of companion dogs, responsible for up to 2% of all canine deaths in some susceptible breeds or an estimated 120,000 per year in the US. The canine disease (HSA) often presents in the spleen as acute hemoabdomen secondary to splenic rupture. Even if life-saving splenectomy is performed, median overall survival (OS) is only 48 days, and 1-year survival is negligible. Here we report the analysis of a pilot phase I open-label trial of chemo-immunotherapy performed on consecutively presenting splenectomized canines with histologically verified HSA. Subjects received an abbreviated course of low-dose doxorubicin plus alpha interferon and an autologous dendritic cell-therapy reported to enhance durable CD8+ memory. Disease was monitored monthly by abdominal ultrasound, chest X-ray, and echocardiogram. Median OS in the per protocol population was 109 days including one of five animals that died cancer-free at 16 months after documented resolution of relapsed disease. These results indicate that therapeutic administration of chemo-immunotherapy is both feasible and safe, substantiating the rationale for additional veterinary and human clinical studies.

Ultrastructural Changes and Antitumor Effects of Doxorubicin/thymoquinone-loaded CaCO3 Nanoparticles on Breast Cancer Cell Line

Event Abstract Back to Event Ultrastructural Changes and Antitumor Effects of Doxorubicin/thymoquinone-loaded CaCO3 Nanoparticles on Breast Cancer Cell Line Kehinde M. Ibiyeye1, 2* and Abu Bakar Z. Zuki2* 1 Institute of Bioscience, University Putra Malaysia, Malaysia 2 Laboratory of Molecular Biomedicine, Institute of Bioscience, University Putra Malaysia, Malaysia Ultrastructural Changes and Antitumor Effects of Doxorubicin/thymoquinone-loaded CaCO3 Nanoparticles on Breast Cancer Cell Line Kehinde Muibat Ibiyeye 1, Norshariza Nurdin2, Mokrish Ajat3 and Abu Bakar Zakaria Zuki1,3 1Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia, Selangor, Malaysia 2Genetics and Regenerative Medicine Research Centre, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia 3Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Selangor, Malaysia The corresponding author: Abu Bakar Zakaria Zuki, zuki@upm.edu.my Background Combination chemotherapy of anticancer drugs is extensively being researched since it could reduce multidrug resistance and side effects as a result of lower dosage of each drug. In this study, we evaluated the effects of doxorubicin-loaded (Dox-ACNP), thymoquinone-loaded (TQ-ACNP) and a combined doxorubicin/thymoquinone-loaded cockle shell-derived aragonite calcium carbonate nanoparticles (Dox/TQ-ACNP) on breast cancer cell line and compared with their free drugs counterpart. Methods Cell viability using MTT assay, apoptosis with Annexin V-PI kit, morphological changes using contrast light microscope, scanning electron microscope and transmission electron microscope, cell cycle analysis, invasion assay and scratch assay were carried out. The cell viability was evaluated in breast cancer cell line (MDA MB231), normal breast cells (MDF10A) and normal fibroblast (3T3). Results MDA MB231 IC50 dosage of drug-loaded nanoparticle was not toxic to the normal cells. This was confirmed by light microscopic assessment of cell morphology. The combination therapy showed enhanced apoptosis, reduction in cellular migration and invasion when compared to the single drug loaded nanoparticle and the free drugs. Scanning electron microscope showed presence of cell shrinkage, cell membrane blebbing, while transmission electron microscope showed nuclear fragmentation, disruption of cell membrane, apoptotic bodies, and disruption of mitochondrial cistern. Conclusion The results from this study showed that the combined drug-loaded cockle shell-derived aragonite calcium carbonate nanoparticles (Dox/TQ-ACNP) showed higher efficacy in breast cancer cells at lower dose of doxorubicin or thymoquinone. Keywords: Doxorubicin, Thymoquinone, Nanoparticle, Breast cancer Keywords: Doxorubicin, Thymoquinone, combination therapy, nanoparticle, breast cancer Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Poster Presentation Topic: Cancer Citation: Ibiyeye KM and Zuki AZ (2019). Ultrastructural Changes and Antitumor Effects of Doxorubicin/thymoquinone-loaded CaCO3 Nanoparticles on Breast Cancer Cell Line. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2019.63.00018 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 12 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Ms. Kehinde M Ibiyeye, Institute of Bioscience, University Putra Malaysia, Serdang, Malaysia, kehindebiyeye@gmail.com Prof. Abu Bakar Z Zuki, Laboratory of Molecular Biomedicine, Institute of Bioscience, University Putra Malaysia, Serdang, Malaysia, zuki@upm.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Kehinde M Ibiyeye Abu Bakar Z Zuki Google Kehinde M Ibiyeye Abu Bakar Z Zuki Google Scholar Kehinde M Ibiyeye Abu Bakar Z Zuki PubMed Kehinde M Ibiyeye Abu Bakar Z Zuki Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Zinc Oxide Composites of Doxorubicin in the Form of Coating, Composite Films and Gels with a High Antitumor Activity and Low Toxicity

This work is devoted to the formation doxorubicin (DOX) zinc oxide composites in the form of coating (DOX + ZnO), hydrogels and composite films of DOX with polyvinyl alcohol (DOX + PVA + ZnO) by DC-magnetron deposition of ZnO nanoscale particles (ZnO NPs) on their surfaces (DOX, DOX + PVA) with higher (two times and more) antitumor activity and considerable smaller toxicity at low doses of DOX in compositions compared to the initial drug. Using the methods of spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray Powder Diffraction (XRD), the role of ZnO NPs size on the antitumor activity of doxorubicin zinc oxide compositions is shown. AFM shows presence of many ZnO NPs on the surface DOX. A comparison of the FTIR spectra of DOX and its zinc oxide compositions has shown the presence of new bands of OH valence and deformation vibrations. It is possible to assume that interaction between ZnO and DOX takes place in the form of hydrogen bond, promoting the complexes formation. It is possible that both synergic and hydrogen-bonding ZnO with DOX increase the antitumor activity.

Enhanced chemotherapeutic efficacy of the low-dose doxorubicin in breast cancer via nanoparticle delivery system crosslinked hyaluronic acid

Despite the development of treatment options in breast cancer, many patients die of recurrence and metastasis. Owing to enhanced permeability and retention in solid tumor tissue, nanoparticle (NP) delivery systems have been emerged as novel strategy in cancer chemotherapy. As extracellular matrix, glycosaminoglycan hyaluronan (HA) could bind its surface receptor adhesion molecule CD44 which is strongly expressed on breast cancer. We have previously reported a doxorubicin (DOX)-loaded HA-Lys-LA X-NPs (X-NP-DOX) NP delivery system for breast cancer treatment. In this study, we further investigated the antitumor effect of X-NP-DOX NP delivery system using low-dose DOX in both in vitro and in vivo systems. We demonstrated that low-dose X-NP-DOX possessed the ability for inhibiting MCF-7 breast cancer cell growth, invasion, and migration, and inducing apoptosis in vitro. In in vivo experiments, injection of low-dose X-NP-DOX into tumor-bearing mouse resulted in significant reduction of tumor size. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining further revealed that low-dose X-NP-DOX induced higher percentage of apoptotic cells compared with free DOX or saline. Furthermore, our study demonstrated that low-dose X-NP-DOX inhibited Notch1 and Ras/MAPK pathways, decreased cancer stem cell population, and reduced tumorigenesis compared to free DOX in both in vitro and in vivo settings. Owing to its enhanced efficacy and higher targetability compared to free DOX, low-dose DOX delivered by NP system may be a promising novel strategy for breast cancer treatment.