Enhancement Of Antitumor Effect Research Articles

Immunotherapy with Dendritic Cells Modified with Tumor-Associated Antigen Gene Demonstrates Enhanced Antitumor Effect Against Lung Cancer

BACKGROUND: Immunotherapy using dendritic cell (DC) vaccine has the potential to overcome the bottleneck of cancer therapy. METHODS: We engineered Lewis lung cancer cells (LLCs) and bone marrow–derived DCs to express tumor-associated antigen (TAA) ovalbumin (OVA) via lentiviral vector plasmid encoding OVA gene. We then tested the antitumor effect of modified DCs both in vitro and in vivo. RESULTS: The results demonstrated that in vitro modified DCs could dramatically enhance T-cell proliferation (P<.01) and killing of LLCs than control groups (P<.05). Moreover, modified DCs could reduce tumor size and prolong the survival of LLC tumor-bearing mice than control groups (P<.01 and P<.01, respectively). Mechanistically, modified DCs demonstrated enhanced homing to T-cell–rich compartments and triggered more naive T cells to become cytotoxic T lymphocytes, which exhibited significant infiltration into the tumors. Interestingly, modified DCs also markedly reduced tumor cells harboring stem cell markers in mice (P<.05), suggesting the potential role on cancer stem-like cells. CONCLUSION: These findings suggested that DCs bioengineered with TAA could enhance antitumor effect and therefore represent a novel anticancer strategy that is worth further exploration.

P3.02c-049 Dendritic Cells Modified with Tumor-Associated Antigen Gene Demonstrate Enhanced Antitumor Effect against Lung Cancer: Topic: IT

Immunotherapy involving dendritic cells (DCs) vaccine has the potential to overcome the bottleneck of cancer therapy. Here, we engineered Lewis Lung cancer cells (LLC) and bone marrow derived DCs to express tumor-associated antigen (TAA), ovalbumin (OVA) via lentiviral vector plasmid encoding OVA gene. We then tested the anti-tumor effect of modified DCs both in vitro and in vivo. The results demonstrated that in vitro modified DCs could dramatically enhance T cells proliferation (P < 0.01) and kill LLC significantly than control groups (P < 0.05). Moreover, modified DCs can reduce tumor size and prolong the survival of tumor-bearing mice than control groups (P < 0.01, P < 0.01; respectively). Modified DCs enhanced homing to T-cell-rich compartments and triggered naïve T cells to become cytotoxic T lymphocytes, which exhibited significant infiltration into the tumors. Interestingly, modified DCs also markedly reduced tumor cells harboring stem cell markers in mice (P < 0.05), suggesting the potential role of eliminating cancer stem-like cells in vivo. These findings indicated that DCs bioengineered with TAA may enhance antitumor effect against murine lung cancer through novel mechanism that is worth further exploration.

Gold Nanoshells: Combined Near Infrared Photothermal Therapy and Chemotherapy Using Gold Nanoshells Coated Liposomes to Enhance Antitumor Effect (Small 30/2016).

Gold nanoshell coated oleanolic acid liposomes mediating by chitosan (GNOLs), are designed and successfully synthesized for the first time by D. Gao and co-workers on page number 4103. An excellent near infrared (NIR) photothermal effect, pH-responsive drug controlled release and tumor targeting properties are demonstrated. By combining NIR photothermal therapy and chemotherapy, the smart drug delivery system exhibits a superior antitumor property in vitro and in vivo.

Combined Near Infrared Photothermal Therapy and Chemotherapy Using Gold Nanoshells Coated Liposomes to Enhance Antitumor Effect.

Novel antitumor system based on the targeting photothermal and pH-responsive nanocarriers, gold nanoshells coated oleanolic acid liposomes mediating by chitosan (GNOLs), is designed and synthesized for the first time. The GNOLs present spherical and uniform size (172.03 nm) with zeta potential (20.7 ± 0.4 mV), which are more easily accumulated in tumor. Meanwhile, the GNOLs exhibit a slow and controlled release of oleanolic acid at pH 7.4, as well as a rapid release at pH 5.5, which is beneficial for tumor-targeting drug release. Under near infrared (NIR) irradiation, hyperthermia can be generated by activated gold nanoshells to perform photothermal therapy effect, which triggers drug release from the carriers by activating the gel to liquid crystalline phase transition of the liposomes. Moreover, the NIR assisting drug release can be easily and selectively activated locally due to the spatially and real-timely controllable property of light. The experimental results also verify that the GNOLs with NIR irradiation achieve more ideal antitumor effects than other oleanolic acid formulations in vitro and in vivo. Hence, the drug delivery system exhibits a great potential in chemo-photothermal antitumor therapy.

660. Enhance Antitumor Effect by Combining Oncolytic Virus HF10 and Bevacizumab in the Treatment of Human Breast Cancer Xenograft

Background: The high prevalence and poor prognosis of breast cancer provides a strong rationale for developing new treatment strategies. Oncolytic herpes simplex viruses has a promising prospect because of its selectivity, and the replicating and tumor killing ability. In our study, the antitumor effect by combining oncolytic virus HF10 and Bevacizumab in the treatment of human breast cancer xenograft is evaluated. Methods: The VEGFA gene transcription and protein expression were measured in candidate cell lines (MCF-7,T47D and MDA-MB-231) by RT-PCR, Western blot and ELISA. The MTT analysis was applied to evaluate the efficiency of the combination therapy in vitro. Viral replication was assessed by PCR and plaque assay. Animal models were formed by implanting MDA-MB-231 tumor in the flank site of female BALB/c nude mice. The HF10 group of advanced tumor model received two injections of 106 pfu/dose intratumorally on Day 1 and Day 14. The HF10 group of single tumor model received single injection of 106 pfu/dose intratumorally on Day 1. The Bevacizumab group received 5µg/g Bevacizumab intra-peritoneally twice a week for two weeks. The combination group received both intratumoral HF10 and intraperitoneal Bevacizumab at the same dose of single treatment groups. The tumor diameter was measured twice a week. On Day 3 and Day 36, the tumors were collected and observed respectively. Histopathological parameters were HIF1α, VEGFA, CD31 driven microvascular density, Caspase 3 and HSV-1 antigen. Results: MDA-MB-231 cells have the highest level of VEGFA expression, while T47D cells have the lowest level. The cytotoxic effect of HF10 is time- and dose- dependent in vitro. The combination therapy does not affect viral replication in vitro. The combination group has the smallest tumor volume comparing with other groups in both animal models (P<0.05). The combination therapy induces synergistic antitumor effect in both animal models. Viral distribution is significantly enhanced in the combination group compared to the HF10 group on both Day 3 and Day 36. Enhanced tumor hypoxia and the up-regulation of angiogenesis gene as well as enlarged population of apoptotic cells in the combination group are also demonstrated in the tumor sample on Day 3. Conclusions: Increased angiogenesis effect and limited viral distribution remain obstacles of oncolytic viral therapy. Anti-angiogenesis reagent is considered to be effective to achieve better antitumor effect of oncolytic virus. Our results show that Bevacizumab enhances viral distribution as well as tumor hypoxia and enlarges the population of apoptotic cells, and therefore induces a synergistic antitumor effect. It can be a promising virus-associated agent in the anticancer treatment.

MP03-07 RADIOFREQUENCY ABLATION OF PRIMARY TUMORS COMBINED WITH ANTI-PROGRAMMED DEATH-1 (PD-1) ANTIBODY RESULTS IN AN ENHANCED ANTITUMOR EFFECT AGAINST ADVANCED RENAL CELL CARCINOMA

You have accessJournal of UrologyKidney Cancer: Advanced (including Drug Therapy) I1 Apr 2016MP03-07 RADIOFREQUENCY ABLATION OF PRIMARY TUMORS COMBINED WITH ANTI-PROGRAMMED DEATH-1 (PD-1) ANTIBODY RESULTS IN AN ENHANCED ANTITUMOR EFFECT AGAINST ADVANCED RENAL CELL CARCINOMA Xiaofeng Chang Xiaofeng ChangXiaofeng Chang More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1900AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Radiofrequency ablation therapy (RFA) is a radical treatment for renal cancers and induces tumor antigen-specific immune responses. Immune checkpoint inhibitors targeting the PD-­1 pathway have shown longer overall survival and fewer grade 3 or 4 adverse events in patients with advanced renal cell carcinoma in a randomized, open-label, phase 3 study. However, the patients’ response to PD-­1 inhibition is not consistent and the objective response rate is relatively low. We sought to enhance the antitumor effect of RFA by combining it with PD­1 inhibition. METHODS Balb/c mice were injected subcutaneously with renal cancer cells (Renca) in their bilateral flanks. After the establishment of tumors 10 days after the injection of cancer cells, the mice were treated with IgG alone, anti­PD­-1 monoclonal antibodies (mAbs), surgery/RFA of the subcutaneous tumor on one flank alone, or surgery/ RFA + anti­PD­1. Anti­PD­1 mAbs were administered by intravenous injection every other day for three times. The antitumor effect of the treatment was evaluated by measuring the size of the tumor on the opposite flank and observing the survival time, and the immunological responses were assessed using peripheral blood immune parameters. RESULTS Treatment of mice bearing s.c. tumors with RFA and anti-PD-1 mAbs resulted in significantly greater growth suppression of primary tumors and enhanced survival compared with mice treated with the other modalities (P<0.05). Treatment of a tumor with combination of RFA and i.v anti-PD-1 mAbs also showed antitumor effects against a distant untreated tumor (P<0.05). In the rechallenge test, mice treated with RFA and anti-PD-1 mAbs showed immunologic memory for having the ability to reject subsequent challenges of Renca cells (P<0.05). ELISA analysis showed that mice treated with RFA and i.v anti-PD-1 mAbs had higher level of IFN-γ, TNF-α, IL-2, IL-4 and IL-5 in the peripheral blood after treatment compared with the other groups (P<0.05). CONCLUSIONS The combination of RFA and anti-PD-1 mAbs resulted in distant tumor suppression and a significantly improved survival in this pre­clinical model of advanced RCC. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e21 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Xiaofeng Chang More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Enhancement of antitumor effect by peptide vaccine therapy in combination with anti-CD4 antibody: Study in a murine model

PurposeThe clinical efficacy of cancer peptide vaccine therapy is insufficient. To enhance the anti-tumor effect of peptide vaccine therapy, we combined this therapy with an anti-CD4 mAb (GK1.5), which is known to deplete CD4+ cells, including regulatory T cells (Tregs). MethodsTo determine the treatment schedule, the number of lymphocyte subsets in the peripheral blood of mice was traced by flow cytometry after administration of anti-CD4 mAb. The ovalbumin (OVA)257–264 peptide vaccine was injected intradermally and anti-CD4 mAb was administered intraperitoneally into C57BL/6 mice at different schedules. We evaluated the enhancement of OVA peptide-specific cytotoxic T lymphocyte (CTL) induction in the combination therapy using the ELISPOT assay, CD107a assay, and cytokine assay. We then examined the in vivo metastasis inhibitory effect by OVA peptide vaccine therapy in combination with anti-CD4 mAb against OVA-expressing thymoma (EG7) in a murine liver metastatic model. ResultsWe showed that peptide-specific CTL induction was enhanced by the peptide vaccine in combination with anti-CD4 mAb and that the optimized treatment schedule had the strongest induction effect of peptide-specific CTLs using an IFN-γ ELISPOT assay. We also confirmed that the CD107a+ cells secreted perforin and granzyme B and the amount of IL-2 and TNF produced by these CTLs increased when the peptide vaccine was combined with anti-CD4 mAb. Furthermore, metastasis was inhibited by peptide vaccines in combination with anti-CD4 mAb compared to peptide vaccine alone in a murine liver metastatic model. ConclusionThe use of anti-CD4 mAb in combination with the OVA peptide vaccine therapy increased the number of peptide-specific CTLs and showed a higher therapeutic effect against OVA-expressing tumors. The combination with anti-CD4 mAb may provide a new cancer vaccine strategy.

Co-delivery of Pirarubicin and Paclitaxel by Human Serum Albumin Nanoparticles to Enhance Antitumor Effect and Reduce Systemic Toxicity in Breast Cancers.

In our study, we aimed to develop a codelivery nanoparticulate system of pirarubicin (THP) and paclitaxel (PTX) (Co-AN) using human serum albumin to improve the therapeutic effect and reduce systemic toxicities. The prepared Co-AN demonstrated a narrow size distribution around 156.9 ± 3.2 nm (PDI = 0.16 ± 0.02) and high loading efficiency (87.91 ± 2.85% for THP and 80.20 ± 2.21% for PTX) with sustained release profiles. Significantly higher drug accumulation in tumors and decreased distribution in normal tissues were observed for Co-AN in xenograft 4T1 murine breast cancer bearing BALB/c mice. Cytotoxicity test against 4T1 cells in vitro and antitumor assay on 4T1 breast cancer in vivo demonstrated that the antitumor effect of Co-AN was superior to that of the single drug or free combination. Also, Co-AN induced increased apoptosis and G2/M cell cycle arrest against 4T1 cells compared to that of the single drug formulation. Remarkably, Co-AN exhibited significantly lower side effects regarding bone marrow suppression and organ and gastrointestinal toxicities. This human serum albumin-based codelivery system represents a promising platform for combination chemotherapy in breast cancers.

Targeted concurrent chemoradiotherapy, by using improved microcapsules that release carboplatin in response to radiation, improves detectability by computed tomography as well as antitumor activity while reducing adverse effect in vivo

PurposeThe effect of alginate-hyaluronate microcapsules that release carboplatin in response to radiation was improved by adding ascorbic acid (AA). Materials and MethodsFour measures of the effectiveness of the microcapsules were evaluated: 1) release of carboplatin in response to radiation in vitro and in vivo; 2) detectability of their accumulation by computed tomography (CT) in vivo; 3) enhancement of antitumor effects in vivo; and 4) reduction of adverse effects in vivo. ResultsThere were significant increases in the rupture of microcapsules by adding AA in vitro. Subcutaneously injected microcapsules around the tumor could be detected by using CT and the alteration of CT-values correlated with the accumulation of the microcapsules. Those microcapsules released carboplatin and resulted in synergistic antitumor effect with concomitant radiation. With the encapsulation of carboplatin, chemotherapeutic effects were still observed two weeks after treatment. However, addition of AA did not result in increased antitumor effect in vivo. A reduction in adverse effects was observed with the encapsulation of carboplatin, through localization of carboplatin around the tumor. ConclusionAddition of AA to the materials of microcapsules did not result in increasing antitumor effect. However encapsulation of carboplatin will be useful as a clinical cancer-therapy option.

Abstract 840: Enhancement of antitumor effect of platinum complexes by PXR antagonist

Abstract The goal of this study was to evaluate the enhancing ability of PXR antagonists for the antitumor effect of platinum complex. Cell lines used in this study were human hepatoma cell line HepG2, human ovarian cancer cell line 2008 and human colon cancer cell line HCT116. Changes in mRNA expression were assessed by real-time RT-PCR, and the ability of apoptosis induction was assessed as caspase-3 activity. Cytotoxicity of platinum complexes was assessed by SRB assay, and IC75 and IC90 values of them were determined. They did not induce apoptosis at IC75 but did it markedly at IC90. Previously, we reported that though apoptosis in HepG2 was induced by IC90 dose of CDDP, addition of a PXR agonist, rifampicin, from 24-hr before treatment and during treatment with CDDP was almost suppressed. Moreover, we found that apoptosis in 2008 and HCT116 induced by IC90 dose of CDDP or oxaliplatin was suppressed by rifampicin. That suggests a nuclear receptor PXR affects on the cytotoxicity of platinum complexes for cancer cells other than HepG2. Ketoconazole (KTZ) and phenethyl isothiocyanate (PEITC) were selected as PXR antagonists that were added with platinum complex. Both drugs at 30 μM induced cytostatic cell growth inhibition in HepG2, 2008 and HCT116 but did not affect on caspase-3 activity compared with control in those cells. When these PXR antagonists at 30 μM were added to cancer cell lines from 24-hr before treatment and during treatment with CDDP at IC75, caspase-3 activity was significantly increased compared with that in CDDP alone. Also, when cells were exposed to CDDP and a PXR antagonist without PXR antagonist pretreatment, caspase-3 activity was increased but the level was reduced compared with that in the combination with pretreatment. Similarly, oxaliplatin in combination with KTZ or PEITC markedly induced apoptosis in HCT116. In HepG2, KTZ reduced the level of MRP2 mRNA. That suggests that pretreatment with KTZ might increase the intracellular platinum content and enhance the cytotoxicity of platinum complex. We concluded that PXR antagonist can be an agent enhancing the antitumor activity of platinum complex, and one of the mechanism is to suppress the expression of the platinum efflux transporter. Citation Format: Shuichi Kishimoto, Erika Bou, Kaho Higashi, Ryosuke Suzuki, Shoji Fukushima. Enhancement of antitumor effect of platinum complexes by PXR antagonist. [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 840. doi:10.1158/1538-7445.AM2014-840

Melatonin enhances the anti-tumor effect of fisetin by inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways.

Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy.

Combination of Bubble Liposomes and High-Intensity Focused Ultrasound (HIFU) Enhanced Antitumor Effect by Tumor Ablation

Ultrasound (US) is used in the clinical setting not only for diagnosis but also for therapy. As a therapeutic US technique, high-intensity focused ultrasound (HIFU) can be applied to treat cancer in a clinical setting. Microbubbles increased temperature and improved the low therapeutic efficiency under HIFU; however, microbubbles have room for improvement in size, stability, and targeting ability. To solve these issues, we reported that "Bubble liposomes" (BLs) containing the US imaging gas (perfluoropropane gas) liposomes were suitable for ultrasound imaging and gene delivery. In this study, we examined whether BLs and HIFU could enhance the ablation area of the tumor and the antitumor effect. First, we histologically analyzed the tumor after BLs and HIFU. The ablation area of the treatment of BLs and HIFU was broader than that of HIFU alone. Next, we monitored the temperature of the tumor, and examined the antitumor effect. The temperature increase with BLs and HIFU treatment was faster and higher than that with HIFU alone. Moreover, treatment with BLs and HIFU enhanced the antitumor effect, which was better than with HIFU alone. Thus, the combination of BLs and HIFU could be efficacious for cancer therapy.

Enhancement of Anti-tumor Activity of Newcastle Disease Virus by the Synergistic Effect of Cytosine Deaminase

This study was conducted to investigate enhancement of anti-tumor effects of the lentogenic Newcastle disease virus Clone30 strain (NDV rClone30) expressing cytosine deaminase (CD) gene against tumor cells and in murine groin tumor-bearing models. Cytotoxic effects of the rClone30-CD/5-FC on the HepG2 cell line were examined by an MTT method. Anti-tumor activity of rClone30-CD/5-FC was examined in H22 tumor-bearing mice. Compared to the rClone30-CD virus treatment alone, NDV rClone30-CD/5-FC at 0.1 and 1 MOIs exerted significant cytotoxic effects (P<0.05) on HepG2 cells. For treatment of H22 tumor-bearing mice, recombinant NDV was injected together with 5-FC given by either intra-tumor injection or tail vein injection. When 5-FC was administered by intra-tumor injection, survival for the rClone30-CD/5-FC-treated mice was 4/6 for 80 days period vs 1/6 , 0/6 and 0/6 for the mice treated with rClone30-CD, 5-FC and saline alone, respectively. When 5-FC was given by tail vein injection, survival for the rClone30-CD/5-FC-treated mice was 3/6 vs 2/6 , 0/6 and 0/6 for the mice treated with rClone30-CD, 5-FC or saline alone, respectively. In this study, NDV was used for the first time to deliver the suicide gene for cancer therapy. Incorporation of the CD gene in the lentogenic NDV genome together with 5-FC significantly enhances cell death of HepG2 tumor cells in vitro, decreases tumor volume and increases survival of H22 tumor-bearing mice in vivo.

Abstract B87: Preclinical investigation of the potentiation in antitumor effect of TAS-102, a novel oral anti-neoplastic nucleoside agent, in combination with irinotecan (CPT-11) in colorectal cancer.

Abstract Background: Irinotecan (CPT-11) is a topoisomeraseI (TopoI) inhibitor, which is widely used for the treatment of metastatic colorectal cancer. CPT-11 inhibits DNA religation by TopoI, thus it stabilizes DNA-TopoI complexes and subsequently induces cytotoxicity. TAS-102, a novel oral antitumor agent, consisting of trifluorothymidine(FTD) and thymidine phosphorylase inhibitor, has reported promising clinical results in metastatic colorectal cancer. Several reports indicated that aberrant nucleoside incorporation into DNA, such as with cytarabine or gemcitabine, enhanced DNA-TopoI complexes. FTD, the effector of TAS-102, is a nucleoside which is efficiently incorporated and retained into DNA. Here, we evaluated the potency of TAS-102 in combination with CPT-11 in vitro and in vivo Materials and Methods: The combinational effect of FTD and SN-38 which is the active metabolite of CPT-11 was evaluated with several treatment schedules. Various colorectal cancer cell lines (SW48, SW620, LS174T and HCT116) were used in this assay. In one set, cells were washed after a 24 hour pre-exposure to FTD followed by a 48 hour exposure to SN-38 (FTD pre-exposure schedule); in the other set, cells were washed after a 6 hour pre-exposure to SN-38 followed by a 66 hour exposure to FTD (SN-38 pre-exposure schedule). A combinational intensity was estimated by using a combination index (CI) which indicates synergism (CI&amp;lt;0.8), additivity (0.8&amp;lt;CI&amp;lt;1.2), or antagonism (CI&amp;gt;1.2). Additionally, the antitumor effect of TAS-102 in combination with CPT-11 was investigated in a human colorectal cancer xenograft model. TAS-102 was orally administered for 14 days consecutively and CPT-11 was intravenously administered once a week to mice. Results: The combination of SN-38 and FTD showed a synergistic effect (SW48, SW620 and LS174T) or an additive effect (HCT116) in both the FTD pre-exposure schedule as well as the SN-38 pre-exposure schedule. Also, the enhancement of antitumor effect of TAS-102 in combination with CPT-11 was observed in vivo. Furthermore, these cell lines had various genotypes as regards KRAS, PI3CA and other DNA repair enzymes frequently detected in colorectal cancer, indicating that the combination's efficacy seemed to be independent of genetic status. Conclusion: TAS-102/CPT-11 represents a novel combination strategy for the treatment of advanced colorectal cancer. A synergistic effect was observed in both schedules tested, suggesting that various underlying mechanisms may exist. One potential mechanism is that FTD uptake or incorporation into DNA is increased by TopoI inhibition, and that FTD incorporation then further stabilizes the CPT-11 induced cleavable complex. However, the precise mechanism needs to be elucidated in the future. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B87. Citation Format: Keiji Ishida, Nozomu Tanaka, Sayaka Tsukioka, Kokoro Eshima, Akio Fujioka, Keisuke Yamamura, Satoko Ito, Kenichi Matsuo, Teruhiro Utsugi. Preclinical investigation of the potentiation in antitumor effect of TAS-102, a novel oral anti-neoplastic nucleoside agent, in combination with irinotecan (CPT-11) in colorectal cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B87.

Augmenting adoptive T cell therapy through universal chimeric costimulators

Adoptive transfer of Tumor Infiltrating Lymphocytes (TIL), T-cell receptor (TCR)-transduced PBL and Chimeric Antigen Receptor (CAR)-transduced PBL have proven to be clinically effective. CARs have evolved by introducing cytoplastic costimulatory domains. Higher cytokine secretion and longer persistence of CAR-transduced T-cells in vivo imply important roles of costimulatory signals. In contrast, costimulation of TIL or TCR-transduced PBL in vivo relies on the expression of costimulatory receptors on T-cells and ligands on tumor cells or antigen presenting cells (APCs). One way to give T-cells their desired costimulation signal independent of the endogenous receptor/ligand expression would be to introduce a fusion molecule that is comprised of a receptor whose ligand is frequently expressed on tumor cells and an intra-cellular costimulatory domain. In a pursuit for a “universal costimulator” that is applicable to various tumors, we produced fusions of CD2 and various costimulators such as CD28, 4-1BB, ICOS, CD27 and OX-40 (Figure ​(Figure1).1). CD2 is the receptor for CD58 that is expressed on various tumor cells. Since CD2-CD58 complex localizes to the Supramolecular Activation Complex (SMAC) on activation of TCR, CD2-costimulators may signal in a TCR-activation dependent manner. Human PBL were retrovirally transduced with genes that encode NY-ESO-1-reactive TCR and each CD2-costimulator. In vitro co-culture assay showed higher IFN-γ and IL-2 secretion by CD2-CD28 and higher IFN-γ by CD2-OX40. To examine the in vivo effect of these fusion costimulators, vascularized SK23 melanoma tumor was established in NOD scid gamma (NSG) immunodeficient mice and human CD8+ T-cells transduced with anti-NY-ESO1 TCR and each fusion costimulator were injected. Out of five costimulators tested, CD2-CD28 showed a significant enhancement of anti-tumor effect. These results suggest that the CD2-CD28 costimulator may improve TIL and TCR-transduced PBL therapy. Figure 1

Intelligently Targeted Drug Delivery and Enhanced Antitumor Effect by Gelatinase-Responsive Nanoparticles

AimsThe matrix metalloproteinase (MMP) 2/9, also known as collagenases IV and gelatinases A/B, play a key role in cancer invasion and metastasis. However, the clinical trials of the MMP inhibitors (MMPIs) ended up with disappointing results. In this paper, we synthesized a gelatinase-responsive copolymer (mPEG-PCL) by inserting a gelatinase cleavable peptide (PVGLIG) between mPEG and PCL blocks of mPEG-PCL for anticancer drug delivery to make use of MMP2/9 as an intelligent target for drug delivery.Materials and MethodsmPEG-pep-PCL copolymer was synthesized via ring-opening copolymerization and double-amidation. To evaluate whether Nanoparticles (NPs) prepared from this copolymer are superior to NPs prepared from mPEG-PCL, NPs prepared from mPEG-PCL copolymer were used as positive control. Docetaxel-loading NPs using mPEG-pep-PCL and mPEG-PCL were prepared by nano-precipitation method, mentioned as Gel-NPs and Con-NPs, respectively. The morphologic changes of the NPs after treatment with gelatinases were observed macroscopically by spectrophotometer and microscopically by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The cellular uptake amount and cytotoxicity of Gel-NPs and Con-NPs, respectively, in cell lines with different levels of gelatinase expression were studied. Moreover, the cytotoxicity study on the primary cancer cells isolated from pericardial fluids from a patient with late-stage lung cancer was conducted.ResultsThe Gel-NPs aggregated in response to gelatinases, which was confirmed macroscopically and microscopically. The cellular uptake amount of Gel-NPs was correlated with the level of gelatinases. The in vitro antitumor effect of Gel-NPs was also correlated with the level of gelatinases and was superior to Taxotere (commercially available docetaxel) as well as the Con-NPs. The cytotoxicity study on the primary lung cancer cells also confirmed the effectiveness of Gel-NPs.ConclusionThe results in this study preliminarily demonstrated the effectiveness of gelatinase-responsive targeting strategy and the prospect of this intelligent nano-drug delivery system though further studies are needed.

Enhanced Antitumor Effect of Curcumin Liposomes with Local Hyperthermia in the LL/2 Model

Curcumin previously was proven to inhibit angiogenesis and display potent antitumor activity in vivo and in vitro. In the present study, we investigated whether a combination curcumin with hyperthermia would have a synergistic antitumor effect in the LL/2 model. The results indicated that combination therapy significantly inhibited cell proliferation of MS-1 and LL/2 in vitro. LL/2 experiment model also demonstrated that the combination therapy inhibited tumor growth and prolonged the life span in vivo. Furthermore, combination therapy reduced angiogenesis and increased tumor apoptosis. Our findings suggest that the combination therapy exerted synergistic antitumor effects, providing a new perspective fpr clinical tumor therapy.

Abstract 3316: Oncolytic adenovirus-armed p53 induces apoptosis significantly through upregulating miR-93 and 106b in human osteosarcoma cells..

Abstract Bone and soft tissue sarcomasare the third most common cancer in children and account for 15.4% of all childhood malignancies. About one fourth of the patients show a poor response to conventional chemo-radiotherapy, resulting in subsequent recurrence and leading to a poor prognosis. Therefore, the development of a novel therapeutic strategy is required. We previously developed an oncolytic adenovirus, OBP-301 (Telomelysin), in which the hTERT gene promoter drives the expression of the E1A and E1B genes linked to an internal ribosome entry site (IRES). Recently, we revealed that OBP-301 shows the cytopathic activity in human bone and soft tissue sarcoma cells. However, some human osteosarcoma cells (MNNG/HOS, SaOS-2) were less sensitive to cytopathic activity of OBP-301. Therefore, we developed a telomerase-specific p53-armed oncolytic adenovirus (OBP-702). In this study, we examined the antitumor effect of OBP-702 in OBP-301-resistant osteosarcoma cells, and revealed the mechanism. We compared the antitumor effects of OBP-702 and OBP-301 using XTT assay. The 50% inhibiting dose (ID50) value of OBP-702 and OBP-301 for each cell was calculated using cell viability data obtained on day 5 after virus infection. We further evaluated the expression of p53, p21 and cleaved-PARP proteins using western blot analysis in OBP-301-resistant osteosarcoma cells after infection with OBP-702 or Ad-p53, which is a p53-expressing replication-defective adenovirus. OBP-702 showed more cytopathic activity compared to OBP-301. The ID50 value of OBP-702 was much lower than that of OBP-301 in all cell lines. Western blot analysis showed OBP-702 infection induced the cleavage of PARP in a dose-dependent manner and cell cycle analysis also showed that OBP-702 induced the highest percentages of sub-G1 population in MNNG/HOS cells compared to Ad-p53 or OBP-301. These results suggest that OBP-702 induces increased apoptosis compared to Ad-p53 or OBP-301. OBP-702 infection induced more profound p53 expression than Ad-p53, but p53-downstream target p21 proteins were not activated by OBP-702. The expression levels of miR-93 and miR-106b increased after OBP-702 infection. When SaOS-2 cells were infected with Ad-p53 at an MOI of 10 for 48 hours, pre-transfection with miR-93, miR-106b or both efficiently suppressed Ad-p53-induced p21 expression. These results suggest that OBP-702 suppresses p21 expression through E1A-dependent upregulation of miR-93 and miR-106b. In conclusion, we have clearly demonstrated that the p53-expressing oncolytic adenovirus OBP-702 has a much stronger antitumor effect than OBP-301 and Ad-p53. Oncolytic adenovirus-mediated p53 gene transduction would induce profound p53 expression without p21 activation regulated by miR-93 and 106b, resulting in the enhancement of antitumor effect. Citation Format: Joe Hasei, Tsuyoshi Sasaki, Hiroshi Tazawa, Yuuri Hashimoto, Toshiyuki Kunisada, Yasuo Urata, Toshifumi Ozaki, Toshiyoshi Fujiwara. Oncolytic adenovirus-armed p53 induces apoptosis significantly through upregulating miR-93 and 106b in human osteosarcoma cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3316. doi:10.1158/1538-7445.AM2013-3316

Enhancement of Antitumor Effects of a New Boron Compound Combined with Ultrasound on the Mouse Ascites Tumor

Enhancement of Antitumor Effects of a New Boron Compound Combined with Ultrasound on the Mouse Ascites Tumor

Enhanced Antitumor Effect of Combination Therapy With Gemcitabine and Guggulsterone in Pancreatic Cancer

Guggulsterone is a dietary plant sterone possessing therapeutic potential against cancers. However, the antitumor effect of this natural compound on pancreatic cancer has not been determined yet. This study was designed to investigate the therapeutic efficacy of guggulsterone in pancreatic cancer. In this study, we examined the effect of guggulsterone on cell proliferation and apoptosis in pancreatic cancer cell lines, and then, we investigated the mechanisms responsible for the effect of guggulsterone. Finally, we investigated whether the combination of guggulsterone and gemcitabine had an additional therapeutic effect compared to gemcitabine single regimen in pancreatic cancer cell lines (in vitro) and in a xenograft model using nude mice (in vivo). In vitro, the combination treatment resulted in more growth inhibition and apoptosis through the down-regulation of nuclear factor κB activity with suppression of Akt and BcL-2 and through the activation of c-Jun NH(2)-terminal kinase and Bax in pancreatic cancer cell lines. In vivo, the combination therapy augmented tumor growth inhibition through the same mechanisms in tumor tissue. The combination of guggulsterone to gemcitabine enhanced antitumor efficacy through apoptosis induction by suppressing Akt and nuclear factor κB activity and by modulating apoptosis-related protein expression in pancreatic cancer.