Efficient Antitumor Effect Research Articles

Immune Monitoring of Cancer Patients Prior to and During CTLA-4 or PD-1/PD-L1 Inhibitor Treatment.

Targeting the immune checkpoint receptors cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed cell death 1 ligand 1 (PD-L1) represents a very attractive treatment modality for tumor patients. The administration of antibodies against these receptors can promote efficient antitumor effects and can induce objective clinical responses in about 20–40% patients with various tumor types, accompanied by improved survival. Based on their therapeutic efficiency, several antibodies have been approved for the treatment of tumor patients. However, many patients do not respond to checkpoint inhibitor therapy. Therefore, the identification of biomarkers is required to guide patient selection for this treatment modality. Here, we summarize recent studies investigating the PD-L1 expression or mutational load of tumor tissues as well as the frequency and phenotype of immune cells in tumor patients prior to and during CTLA-4 or PD-1/PD-L1 inhibitor treatment.

Sericin nanomicelles with enhanced cellular uptake and pH-triggered release of doxorubicin reverse cancer drug resistance

Drug resistance is the major challenge facing cancer chemotherapy and nanoscale delivery systems based on natural materials, such as sericin, are a promising means of overcoming drug resistance. Yet, no attempt of introducing synthetic poly(γ-benzyl-L-glutamate) (PBLG) onto sericin polypeptide to fabricate a facile biocompatible and biodegradable micelle has been tried. Here, we prepared a polypeptide-based amphiphilic polymer containing hydrophilic sericin polypeptide backbone and PBLG side chains via ring-opening polymerization (ROP) strategy. The introduction of PBLG side chains remarkably enhances the stability of sericin micelles in water. Meanwhile, the micelles exhibited a high loading capacity and pH-responsive release ability for antitumor drug doxorubicin (DOX), called sericin-PBLG-DOX. Owing to the excellent cell membrane penetration of sericin-PBLG, the cellular uptake of DOX when loaded into micelles was improved. Subsequently, sericin-PBLG-DOX was transferred into perinuclear lysosomes, where the release rate of DOX was accelerated. Compared to the same dose of DOX, sericin-PBLG-DOX could induce a more efficient anti-tumor effect both in vitro and in vivo, and these micelles have promise for future clinical applications in overcoming cancer drug resistance with good biosafety, enhanced cellular uptake, pH-triggered drug release, efficient anti-tumor effects, and minimized systemic toxicity.

CEA-EPO质粒的构建及诱导造血干细胞定向生成红细胞疫苗抗结肠癌的研究

目的：研究CEA-EPO质粒的构建及诱导造血干细胞定向生成红细胞疫苗抗结肠癌的研究。方法：将EPO-cDNA插入pcDNA3.1质粒的多克隆位点，用CEA基因启动子替代pcDNA3.1质粒的CMV启动子，构建成CEA-EPO重组质粒。用含抗体CD117磁珠分离纯化和收集小鼠骨髓造血干细胞，用重组腺病毒法将CEA-EPO基因体外转染CEA-EPOmRNA基因到造血干细胞内，检测CEA-EPO基因和蛋白表达，将疫苗注入小鼠体内，进行扩增，使造血干细胞定向生成携带CEA-EPO双基因红细胞，经过提取和纯化获得CEA-EPO基因共转染红细胞疫苗，再进行双基因共转染红细胞疫苗的体外和体内实验。结果：成功收集造血干细胞，流式细胞仪分析结果表明：纯化前后有明显差异(P < 0.05)；检测CEA-EPOmRNA和蛋白表达的结果表明：造血干细胞体外转染CEA-EPOmRNA基因成功，获得CEA-EPO双基因共转染红细胞疫苗；应用细胞红系相关标志抗体GPA和CD71标记，利用流式细胞证实红细胞疫苗培养成功；研究相关疫苗激活的单核细胞对结肠癌细胞株CT26细胞杀伤作用表明：在比例为40:1时，CEA-EPO疫苗组杀伤作用为57.34 ± 1.13，高于空载组、CEA疫苗组和EPO疫苗组(P < 0.05)，体内试验的成瘤性研究表明：CEA-EPO疫苗组肿瘤的生长的大小为0.29 ± 0.11 (cm3)；高于其他各组的大小(P < 0.05)，CEA-EPO疫苗组的成活期分别为：69 ± 6.91天，高于其他各组的大小(P < 0.05)；CEA-EPO疫苗组在肿瘤大小和小鼠的生存时间上，与空载组、CEA疫苗组，EPO疫苗组之间差异有统计学意义(P < 0.05)。结论：携带CEA-EPO双基因肿瘤抗原的红细胞疫苗对结肠癌有明显的抗肿瘤作用，既可以诱导造血干细胞定向分化成红细胞疫苗，又可以合成肿瘤抗原的红细胞疫苗，是临床治疗结肠的重要疫苗。 Objective: To investigate the effects of recombinant adenovirus-mediated co-transfection of CEA gene and EPO gene on promoting hematopoietic stem cell directly producing erythrocyte vaccine against colon cancer. Method: The expression adenovirus vectors carrying CEA and EPO or green fluorescent protein (GFP) gene were constructed respectively, and recombinant adenovirus car-rying CEA, EPO or GFP were packaged and produced respectively. The bone marrow-derived MSCs of mice were isolated and cultured in vitro by anti-CD117magnetic bead separation, and were transfected with CEA (CEA group), EPO (EPO group) or GFP(GFP group), co-transfected with CEA and EPO (CEA and EPO group), or transfected with no virus (controlgroup). The expression of CEA and EPO gene and protein after transfection in supernatant fluid of culture was detected by RT-PCR and western blot in each group. We have checked and obtained the vaccine with co-transfection of CEA gene and EPO gene by cell red line marker antibody CD71 and GPA, then we carried on experiments with the vaccine in vitro and in vivo. Result: We have successfully gathered the hematopoietic stem cells; flow cytometry analysis result showed that there were significant differences before and after purification (P < 0.05). The expression of double genes (CEA-EPO gene) and protein shows CEA-EPO gene were successfully transfected into the hematopoietic stem cells. We have confirmed erythrocyte vaccine with co-transfection of CEA and EPO gene by antibody CD71 and GPA with flow cytometry. The monocytes cytotoxicity on colon cancer cell line CT26 showed that CEA-EPO group was 57.34 ± 1.13% in proportion of 40:1. Compared with CEAg group and EPO group, there was significant difference between them (P < 0.05). In the experimentation of neoplasma format, the size of murine growth of tumor was 0.29 ± 0.11 cm3 differently in the group of CEA-EPO group; the number of murine live time on day was 69 ± 6.91 days. Compared with the group of CEA and plasmid, EPO, the group of CEA-EPO was significant differences in size and live time (P < 0.05). Conclusion: The erythrocyte vaccine with co-transfection of CEA gene and EPO gene has efficient anti-tumor effects on colon cancer. It not only can promote hematopoietic stem cell directly producing erythrocyte vaccine, but also can produce tumor Antigen vaccine against stomach cancer.

Injectable and Self-Healing Thermosensitive Magnetic Hydrogel for Asynchronous Control Release of Doxorubicin and Docetaxel to Treat Triple-Negative Breast Cancer.

Integration of two or more drugs into a multiagent delivery system has been considered to have profound impact on both in vitro and in vivo cancer treatment due to their efficient synergistic effect. This study presents a cheap and simple chitosan hydrogel cross-linked with telechelic difunctional poly(ethylene glycol) (DF-PEG-DF) for synthesis of an injectable and self-healing thermosensitive dual-drug-loaded magnetic hydrogel (DDMH), which contains both doxorubicin (DOX) and docetaxel (DTX) for chemotherapy and iron oxide for magnetic hyperthermia induced stimuli responsive drug release. The as-prepared DDMH not only have good biocompatibility but also exhibit unique self-healing, injectable, asynchronous control release properties. Meanwhile, it shows an excellent magnetic field responsive heat-inducing property, which means that DDMH will produce a large amount of heat to control the surrounding temperature under the alternative magnetic field (AMF). A remarkably improved synergistic effect to triple negative breast cancer cell line is obtained by comparing the therapeutic effect of codelivery of DOX and DTX/PLGA nanoparticles (DTX/PLGA NPs) with DOX or DTX/PLGA NPs alone. In vivo results showed that DDMH exhibited significant higher antitumor efficacy of reducing tumor size compared to single drug-loaded hydrogel. Meanwhile, the AMF-trigger control release of drugs in codelivery system has a more efficient antitumor effect of cancer chemotherapy, indicating that DDMH was a promising multiagent codelivery system for synergistic chemotherapy in the cancer treatment field.

MiR-375 delivered by lipid-coated doxorubicin-calcium carbonate nanoparticles overcomes chemoresistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent and lethal disease that is characterized by drug resistance. Doxorubicin (DOX) is a widely used chemotherapeutic drug and miR-375 has been shown to be a tumor suppressor in HCC. Here, we reported that miR-375 and DOX co-loaded into lipid-coated calcium carbonate nanoparticles (LCC-DOX/miR-375 NPs), enhanced the anti-tumor effects through combination therapy, and were highly effective in reversing drug resistance in HCC. LCC-DOX/miR-375 NPs were prepared by a reverse microemulsions method. In vitro, LCC-DOX/miR-375 NPs exhibited enhanced intracellular accumulation, pH-sensitive DOX release and potent cytotoxicity. In vivo, LCC-DOX/miR-375 NPs showed efficient antitumor effect both in xenograft and primary HCC murine models. Our results showed that the LCC-DOX/miR-375 nanoparticles provide a novel strategy to overcome the drug resistance and promote addictive effect between miR-375 and DOX in HCC.

Synthesis of N-methylpiperidin-4-one derivatives and evaluation of their anti-endometrial cancer activity

Four novel N-methylpiperidin-4-one derivatives were synthesized and characterized by IR, 1H NMR, HRMS, and single crystal X-ray crystallography. The anticancer activity of these compounds was studied on five human endometrial cancer cell lines (RL-95-2, HEC-1A, HEC-1B, AN3CN and HECCL-1). Efficient antitumor effect was found for the 3,5-difluorophenyl- and 3-cyanophenyl-substituted derivatives.

Multifunctional Nanosystem for Synergistic Tumor Therapy Delivered by Two-Dimensional MoS2.

A multifunctional nanosystem based on two-dimensional molybdenum disulfide (MoS2) was developed for synergistic tumor therapy. MoS2 was stabilized with lipoic acid (LA)-modified poly(ethylene glycol) and modified with a pH-responsive charge-convertible peptide (LA-K11(DMA)). Then, a positively charged photosensitizer, toluidine blue O (TBO), was loaded on MoS2 via physical absorption. The negatively charged LA-K11(DMA) peptide was converted into a positively charged one under acidic conditions. Charge conversion of the peptide could reduce the binding force between positively charged TBO and MoS2, leading to TBO release. Furthermore, the positively charged nanosystem was easily endocytosed by cells. Photo-induced hyperthermia of MoS2 in the tumor areas could promote TBO release and exhibited photothermal therapy. In vitro and in vivo results demonstrated that fluorescence and photo-induced reactive oxygen species (ROS) generation of TBO were severely decreased by MoS2 under normal conditions. While in the acidic condition, the pH-responsive nanosystem exhibited a highly specific and efficient antitumor effect with TBO release and photo-induced ROS generation, suggesting to be a promising accessory for synergistic tumor therapy.

Gold nanoshell-based betulinic acid liposomes for synergistic chemo-photothermal therapy

A novel synthesis approach is first developed to fabricate a multifunctional smart nanodrug delivery system: gold nanoshell-coated betulinic acid liposomes (AuNS-BA-Lips) mediated by a glutathione. The AuNS-BA-Lips exhibited good size distribution (149.4±2.4nm), preferable photothermal conversion ability and synergistic chemo-photothermal therapy. Additionally, the absorption wavelength of AuNS-BA-Lips showed a significantly red-shifted to near infrared (NIR) region, which can strongly absorbed NIR laser and efficiently convert it into localized heat, thus providing controlled drug release and antitumor thermotherapy. Moreover, the nanocarriers excited by NIR light significantly promoted cell uptake compared to those without irradiation, resulting in an enhanced intracellular drug accumulation. Upon NIR irradiation, the AuNS-BA-Lips showed highly efficient antitumor effects on tumor-bearing mice with an inhibition rate of 83.02%, thus demonstrating a remarkable synergistic therapeutic effect of chemotherapy and thermotherapy. Therefore, this work provides new insight into developing a multifunctional antitumor drug.

X-ray visible and doxorubicin-loaded beads based on inherently radiopaque poly(lactic acid)-polyurethane for chemoembolization therapy

The aim of current study was to develop drug-loaded polymeric beads with intrinsic X-ray visibility as embolic agents, targeting for noninvasive intraoperative location and postoperative examination during chemoembolization therapy. To endow polymer with inherent radiopacity, 4,4′-isopropylidinedi-(2,6-diiodophenol) (IBPA) was firstly synthesized and employed as a contrast agent, and then a set of radiopaque iodinated poly(lactic acid)-polyurethanes (I-PLAUs) via chain extender method were synthesized and characterized. These I-PLAU copolymers possessed sufficient radiopacity, in vitro non-cytotoxicity with human adipose-derived stem cells, and in vivo biocompatibility and degradability in rabbit model via intramuscular implantation. Doxorubicin (DOX), as a chemotherapeutic agent, was further incorporated into I-PLAU beads via a double emulsification (W/O/W) method. For drug release, two ratios of DOX-loaded I-PLAU beads exhibited calibrated size (200-550μm), porous internal structure, good X-ray visibility, evenly drug loading as well as tunable drug release. A preliminary test on in vitro tumor cell toxicity demonstrated that the DOX-loaded I-PLAU beads performed efficient anti-tumor effect. This study highlights novel X-ray visible drug-loaded I-PLAU beads used as promising embolic agents for non-invasive in situ X-ray tracking and efficient chemotherapy, which could bring opportunities to the next generation of multifunctional embolic agents.

Enhanced Oncolytic Activities of the Telomerase-Specific Replication-Competent Adenovirus Expressing Short-Hairpin RNA against Dicer.

Oncolytic viruses have been receiving much attention as potential agents for cancer treatment. Among the various types of oncolytic viruses, the telomerase-specific replication-competent adenovirus (TRAD), which carries the tumor-specific promoter-driven E1 gene expression cassette, exhibits efficient antitumor effects. The development of a novel TRAD that shows higher replication efficiency and antitumor activity would be highly beneficial for safer and more efficient cancer therapy. We recently demonstrated that the endoribonuclease Dicer significantly inhibits the replication of wild-type adenovirus (Ad) via the processing of viral-associated (VA)-RNAs, which are Ad-encoded small noncoding RNAs, and that the knockdown of Dicer leads to enhanced VA-RNA expression and Ad replication after infection with wild-type Ad. Based on these findings, we herein developed a novel TRAD expressing short-hairpin RNA against Dicer (shDicer; TRAD-shDicer). After infection, TRAD-shDicer efficiently induced the knockdown of Dicer. TRAD-shDicer showed significantly higher replication efficiency and tumor cell lysis activity compared with the conventional TRAD in tumor cells. The Dicer expression levels and viabilities of normal cells were not altered by infection with TRAD-shDicer. These results indicate that TRAD-shDicer is a potent antitumor reagent by virtue of its enhanced oncolytic activity. Mol Cancer Ther; 16(1); 251-9. ©2016 AACR.

Near-infrared photoimmunotherapy with galactosyl serum albumin in a model of diffuse peritoneal disseminated ovarian cancer.

Near-infrared photoimmunotherapy (NIR-PIT) is a highly cell-selective cancer therapy based on an armed antibody conjugated with a phthalocyanine-based photo-absorber, IRDye700DX (IR700). NIR-PIT can quickly kill target cells that express specific proteins on the cellular membrane but only when the antibody-IR700 conjugate binds to the cell membrane and is then exposed to NIR light. NIR-PIT is highly selective based on the specificity of the antibody. Galactosyl serum albumin (GSA) is composed of albumin decorated with galactose molecules conjugated to the carboxyl groups of albumin. GSA binds to beta-D-galactose receptors, a surface lectin, which are overexpressed on the cell surface of many cancers, including ovarian cancers and is quickly internalized after binding. Here, we demonstrate the feasibility of NIR-PIT in a model of disseminated peritoneal ovarian cancer (SHIN3 cells) using GSA-IR700 that binds to beta-D-galactose receptors. GSA-IR700 bound quickly to SHIN3 cells, then accumulated in the endo-lysosomes. Cell-specific killing was observed in vitro, yet a relatively large dose of NIR light exposure was required for cell killing compared to antibody-IR700 conjugates. To evaluate in vivo therapeutic effects of GSA-IR700 NIR-PIT, peritoneal disseminated SHIN3 tumor-bearing mice were separated into four groups: no treatment; NIR light only; GSA-IR700 only; and GSA-IR700 NIR-PIT. Repeated NIR-PIT showed significant suppression of tumor based on bioluminescence compared to the other groups (p < 0.05). Thus, repeated NIR-PIT using GSA-IR700 can achieve efficient antitumor effects, although GSA-IR700 NIR-PIT was less effective than antibody-IR700 NIR-PIT conjugates likely due to the rapid internalization of GSA-IR700.

A Nanoparticle Carrier for Co-Delivery of Gemcitabine and Small Interfering RNA in Pancreatic Cancer Therapy.

BACKGROUND: The concept of precision medicine to treat cancer shows promise and a co-delivery carrier for chemotherapy drugs and target genes is the key tool for both basic research and clinical application. To address this, we developed a cancer-targeting nanoparticle vector to transfer gemcitabine (Gem) and small interfering RNA (siRNA) to pancreatic cancer. METHODS: Iron oxide nanoparticles (IONPs) resonant at 15 nm were conjugated with the single chain variable fragment (scFv) against CD44v6 (scFvCD44v6), which has proven pancreatic cancer-targeting specificity as reported in our previous study. Gem was then linked through a lysosomally cleavable tetrapeptide linker, resulting in a scFv-targeted nanoparticle construct, which was subsequently conjugated to siRNA targeting the Bmi-1 oncogene (siBmi-1) to obtain the multifunctional nanoparticle scFv-Gem-siBmi-1-NPs. A series of biological experiments were performed to test its biophysical characterization, gene silencing efficacy and anti-tumor effect in vitro and in vivo. RESULTS: The multifunctional nanoparticle not only possesses an ultra-small size of approximately 80 nm, excellent biocompatibility and biodegradability, but also exerts a synergistic anti-tumor effect both in vitro and in vivo, such as inhibition of tumor cell growth, invasion and migration, reduction of cell cycle progression and promotion of tumor apoptosis. Furthermore, this nanoparticle can efficiently target pancreatic cancer in vivo, resulting in the enhanced bioavailability and efficacy of Gem. CONCLUSION: scFv-Gem-siBmi-1-NPs provide an effective and targeted co-delivery of Gem and siBmi-1 to pancreatic cancer, and exert an efficient and corporate anti-tumor therapeutic effect. This prospective vector shows promise for precise treatment of pancreatic cancer.

Abstract 1945: Identification of a miRNA/mRNA network driving non-small cell lung cancer (NSCLC) dissemination

Abstract Background: Non-small cell lung cancer (NSCLC) is one of the most aggressive tumor entities and first data indicate that microRNAs (miRNAs) are central regulators of NSCLC dissemination. Since each miRNA is able to modulate the expression of several transcripts, they are promising targets for the development of drugs that cause efficient antitumor effects and low resistance. However, the relevant network of miRNA/mRNA driving NSCLC metastasis has not been identified yet. Methods: The differential expression of miRNAs was compared between NSCLC samples from patients with and without lymph node metastasis (N1, N2 and N3 vs. N0) in a cohort of The Cancer Genomic Atlas (TCGA) database (n = 449). The dysregulation of the miRNAs in tumors versus normal lung samples (n = 39) was also analyzed. For validation, fresh-frozen samples from an independent patient cohort (n = 108) were analyzed by qRT-PCR. The role of selected miRNAs in tumor dissemination was assessed by migration and invasion experiments after transfection of respective antagomirs and agomirs in NSCLC cells (time-lapse microscopy). The novel algorithm “miRlastic” was used to identify potential miRNA targets through the integration of miRNA-mRNA expression data by negative multiple linear regression analysis. Moreover, differential methylation of the miRNA genomic locations was studied as a possible mechanism of miRNA dysregulation by analyzing Illumina Infinium 450 k DNA methylation TCGA data (n = 29). Results: By using a stringent selection process, we identified 135 miRNAs differentially induced or reduced in NSCLCs with lymph node metastasis (p≤0.05). Interestingly, 22/135 (16.3%) of the selected miRNAs were located in the chromosomal cluster 14q32.31. Elevated expression of miR-323b, miR-487a and miR-539, which are located in 14q32.31, significantly correlated with poor patient survival. Time-resolved and quantitative analysis of lateral migration illustrated that these miRNAs increased tumor migration without affecting cell viability. Moreover, miRlastic identified several metastasis-related genes as potential downstream targets of these miRNAs. The connection between miRNAs encoded in 14q32.31 and candidate targets was confirmed in NSCLC cell lines (e.g. Pumilio RNA-Binding Family Member-2; PUM2). Lastly, hypomethylation of the 14q32.31 cluster in tumor tissues might explain increased expression of these miRNAs. Conclusions: Our results demonstrate that miRNAs located in the chromosomal cluster 14q32.31 are driving NSCLC dissemination. Therefore, we hypothesize that the coordinated overexpression of these miRNAs is part of a genetic network supporting cancer progression and that they represent promising cancer biomarkers and therapeutic targets. Citation Format: Margarita González-Vallinas, Marco Albrecht, Adriana Pitea, Manuel Rodríguez-Paredes, Damian Stichel, Steffen Sass, Julian Gutekunst, Jennifer Schmitt, Thomas Muley, Michael Meister, Arne Warth, Peter Schirmacher, Fabian J. Theis, Nikola S. Müller, Franziska Matthäus, Kai Breuhahn. Identification of a miRNA/mRNA network driving non-small cell lung cancer (NSCLC) dissemination. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1945.

Efficient antitumor effect of co-drug-loaded nanoparticles with gelatin hydrogel by local implantation.

Tetrandrine (Tet) could enhance the antitumor effect of Paclitaxel (Ptx) by increasing intracellular Reactive Oxygen Species (ROS) levels, which leads to the possibility of co-delivery of both drugs for synergistic antitumor effect. In the current study, we reported an efficient, local therapeutic strategy employing effective Tet and Ptx delivery with a nanoparticle-loaded gelatin system. Tet- and Ptx co-loaded mPEG-PCL nanoparticles (P/T-NPs) were encapsulated into the physically cross-linked gelatin hydrogel and then implanted on the tumor site for continuous drug release. The drug-loaded gelatin hydrogel underwent a phase change when the temperature slowly increased. In vitro study showed that Tet/Ptx-loaded PEG-b-PCL nanoparticles encapsulated within a gelatin hydrogel (P/T-NPs-Gelatin) inhibited the growth and invasive ability of BGC-823 cells more effectively than the combination of free drugs or P/T-NPs. In vivo study validated the therapeutic potential of P/T-NPs-Gelatin. P/T-NPs-Gelatin significantly inhibited the activation of p-Akt and the downstream anti-apoptotic Bcl-2 protein and also inducing the activation of pro-apoptotic Bax protein. Moreover, the molecular-modulating effect of P/T-NPs-Gelatin on related proteins varied slightly under the influence of NAC, which was supported by the observations of the tumor volumes and weights. Based on these findings, local implantation of P/T-NPs-Gelatin may be a promising therapeutic strategy for the treatment of gastric cancer.

Antitumor and Antimetastasis Activities of Heparin-based Micelle Served As Both Carrier and Drug

Effective treatments for tumors are not easy to achieve due to the existence of metastases, which are responsible for most tumor death. Hence, a new drug delivery system is a pressing need, which should be biocompatible, stimuli-responsive, and multifunctional, including antitumor, antimetastasis, and antiangiogenesis effects. However, it is challenging to achieve all of these properties in one drug delivery system. Here, we developed a system of drug DOX and heparin into one self-assemble nanoparticle via pH-sensitive hydrazone bond and hydrophobic groups, deoxycholate. In the process, heparin itself was not only as the hydrophilic segments of the carrier, but also processed multiple biological functions such as antiangiogenesis and antimetastasis effect. The micelle nanoparticle HD-DOX processed good stability and acidic pH-triggered drug release property. After systemic administration, heparin-based micelle nanoparticle showed longer half-time and enhanced accumulation of DOX in tumors through the enhanced permeability and retention effect, leading to more efficient antitumor effects. In addition, heparin could hinder platelet-induced tumor cells epithelial-mesenchymal transition (EMT) and partially affect cell actin cytoskeletal arrangement, resulting in the disorganization of the actin cytoskeleton. Therefore, HD-DOX exhibited significant inhibitory effect on the metastasis in melanoma animal model in C57BL/6 mouse. Meanwhile, benefited from the antiangiogenesis effect of heparin, tube formations in endothelial cells were effectively inhibited and tumor vascular density was decreased by HD-DOX. Taken together, our study developed a self-assembly nanoplatform that both the drug and carrier had therapeutic effects with ideal antitumor efficacy.

Efficient anti-tumor effect of photodynamic treatment with polymeric nanoparticles composed of polyethylene glycol and polylactic acid block copolymer encapsulating hydrophobic porphyrin derivative

To develop potent and safer formulation of photosensitizer for cancer photodynamic therapy (PDT), we tried to formulate hydrophobic porphyrin derivative, photoprotoporphyrin IX dimethyl ester (PppIX-DME), into polymeric nanoparticles composed of polyethylene glycol and polylactic acid block copolymer (PN-Por). The mean particle size of PN-Por prepared was around 80nm and the zeta potential was determined to be weakly negative. In vitro phototoxicity study for PN-Por clearly indicated the significant phototoxicity of PN-Por for three types of tumor cells tested (Colon-26 carcinoma (C26), B16BL6 melanoma and Lewis lung cancer cells) in the PppIX-DME concentration-dependent fashion. Furthermore, it was suggested that the release of PppIX-DME from PN-Por would gradually occur to provide the sustained release of PppIX-DME. In vivo pharmacokinetics of PN-Por after intravenous administration was evaluated in C26 tumor-bearing mice, and PN-Por exhibited low affinity to the liver and spleen and was therefore retained in the blood circulation for a long time, leading to the efficient tumor disposition of PN-Por. Furthermore, significant and highly effective anti-tumor effect was confirmed in C26 tumor-bearing mice with the local light irradiation onto C26 tumor tissues after PN-Por injection. These findings indicate the potency of PN-Por for the development of more efficient PDT-based cancer treatments.

Programmable Biopolymers for Advancing Biomedical Applications of Fluorescent Nanodiamonds

A versatile biopolymer platform for advancing nanodiamonds (NDs) as unique magnetooptic materials for biomedical applications is presented here. Precision biopolymer coatings are designed by chemical reprogramming the functionalities of serum albumin via a straightforward synthesis protocol. Such biopolymers offer high biocompatibility and precise modification with various functional entities due to the large number of available reactive amino acid residues. Premodification of these biopolymers provides a convenient approach to customized surface functionalization of NDs. As an example, the anticancer drug doxorubicin (DOX) is conjugated to the biopolymer with high reproducibility and full characterization. The biopolymer‐coated NDs reveal excellent colloidal stabilities in all physiological media tested, even after loading with high numbers of hydrophobic DOX. The intracellular distribution of NDs and DOX is analyzed in living cells by recording the fluorescence spectra in different cellular compartments, which proves efficient intracellular release of DOX from the carrier. Studies in vitro as well as in a chick tumor xenograft model reveal efficient antitumor effects. The facile and versatile biopolymer coating strategy reported herein will greatly accelerate the availability of customized NDs with reliable and reproducible features to exploit their great potential in single molecular bioimaging, in vivo biosensing, and high resolution quantum optics.

Abstract 3548: Oncolytic adenovirus Ad5dlE1b replication efficiency is dependent on p53 mutation type in cancer cells

Abstract Adenoviruses are the most popular viral DNA vectors in the development of gene therapies and oncolytic therapy. Oncolytic adenoviruses are genetically modified to provide a means of tumor-selectivity by conditionally replicating in tumor cells and substantially killing them via their viral lytic cycle. The p53 molecule is a tumor suppressor protein that regulates the genomic integrity of the cell by controlling apoptosis and cell cycle events. Upon viral infection, normal cell (p53 intact cell) responds through the activation of apoptosis by the p53 dependent pathway. The adenovirus E1B 55kDa protein inactivates p53 and prevents apoptosis leading to progressive viral lytic cycle. Although demonstrating a moderate successes rate in some cancers, Ad deleted E1B 55kDa has not been approved as a standard therapy for all cancer types. Several studies have revealed that E1B deleted Ad replication was independent of p53 status in the cell, as the virus replicated better in some p53 deficient cancers more than others. However, this relationship has not been investigated deeply on the molecular level. However, this relationship has not been investigated deeply on the molecular level. Therefore, the objective of this study is to understand the correlation between p53 status, levels, and functional activity, and oncolytic Ad5dl E1B 55kDa replication efficiency at the molecular level. We evaluated the effect of p53's functional status on the replication efficiency of oncolytic Ad5dl E1B 55kDa. Multiple mutant p53 were engineered and viral growth was evaluated with each mutant form in H1299 cells. P53-R175H mutant successfully rescued viral growth and its transcriptome analysis showed partial loss of wild type activity as well as gain of new function by allowing the virus to grow and to exert its mechanism of selectivity. The mechanism entailed deregulating the expression of specific cellular genes in the p53 pathway, cell cycle and apoptosis, to promote its production leading to efficient oncolytic effect. These results confirmed that onclytic Ad5dl E1B 55kDa sensitivity is mutation type-specific. Therefore, before it is applied clinically as cancer therapy for p53 deficient tumors, the type of p53 mutation must be determined and also more screening for the effect of other mutations should be done for successful rescuing and efficient antitumor effect. Citation Format: Moemen Abdalla, Basma M. Abbas, Yousef Haj-Ahmad. Oncolytic adenovirus Ad5dlE1b replication efficiency is dependent on p53 mutation type in cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3548. doi:10.1158/1538-7445.AM2015-3548

Abstract 792: Usefulness of alternate-day administration of S-1 and leucovorin in a xenograft mouse model of colorectal cancer: A shorter drug-free interval leads to more efficient antitumor effects

Abstract [Background] A clinical trial of S-1 with leucovorin (S-1/LV) in metastatic colorectal cancer (CRC) patients demonstrated promising efficacy; however, the gastrointestinal toxicities were so severe that it has not been applied in the clinical setting. On the other hand, alternate-day administration of S-1 has been proposed to attenuate the adverse events without reducing its anticancer activity. The aim of this study was to confirm the feasibility of alternate-day administration of S-1/LV in in vivo xenograft tumor models. [Methods] Mice were treated with S-1/LV either in a daily group (two weeks of administration followed by two weeks of withdrawal) or an alternate-day group (administration on alternate days for four weeks), then the mice of both groups were sacrificed and the xenograft tumors were resected. To assess the adverse reactions, the body weight changes, the condition of feces, mucosal injury of small intestine and myelosuppression were compared between both groups. Furthermore, tumor volume, tumor growth inhibition (TGI) and the expression of Ki67, TUNEL, cIAP2 and XIAP were analyzed to evaluate the antitumor activity and tumor apoptosis. [Results] Severe weight loss, diarrhea, mucosal injury and myelosuppression were observed only in the daily group; however, no adverse reactions were observed in the alternate-day group, except slight myelosuppression. The TGI in the alternate-day group was better than that in the daily group, possibly resulting from apoptosis of tumor cells due to the suppression of cIAP2. [Conclusion] Our findings suggest that alternate-day administration of S-1/LV for CRC treatment can achieve higher antitumor activity without severe adverse reactions. Therefore, we propose that clinical trials with this regimen should be conducted in CRC patients. Citation Format: Toshihiro Komura, Shinobu Ohnuma, Koh Miura, Tetsuhiko Shirasaka, Taiki Kajiwara, Katsuyoshi Kudoh, Sho Haneda, Masahide Toshima, Atsushi Kohyama, Hiroaki Musha, Takeshi Naitoh, Yu Katayose, Michiaki Unno. Usefulness of alternate-day administration of S-1 and leucovorin in a xenograft mouse model of colorectal cancer: A shorter drug-free interval leads to more efficient antitumor effects. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 792. doi:10.1158/1538-7445.AM2014-792

Signaling Intermediates (MAPK and PI3K) as Therapeutic Targets in NSCLC

The RAS/RAF/MEK/ ERK and the PI3K/AKT/mTOR pathways govern fundamental physiological processes, such as cell proliferation, differentiation, metabolism, cytoskeleton reorganization and cell death and survival. Constitutive activation of these signal transduction pathways is a required hallmark of cancer and dysregulation, on either genetic or epigenetic grounds, of these pathways has been implicated in the initiation, progression and metastastic spread of lung cances. Targeting components of the MAPK and PI3K cascades is thus an attractive strategy in the development of novel therapeutic approaches to treat lung cancer, although the use of single pathway inhibitors has met with limited clinical success so far. Indeed, the presence of intra- and inter-pathway compensatory loops that re-activate the very same cascade, either upstream or downstream the point of pharmacological blockade, or activate the alternate pathway following the blockade of one signaling cascade has been demonstrated, potentially driving preclinical (and possibly clinical) resistance. Therefore, the blockade of both pathways with combinations of signaling inhibitors might result in a more efficient anti-tumor effect, and thus potentially overcome and/or delay clinical resistance, as compared with single agent. The current review aims at summarizing the current status of preclinical and clinical research with regard to pathway crosstalks between the MAPK and PI3K cascades in NSCLC and the rationale for combined therapeutic pathway targeting.