bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2426: JAK inhibitors as new drugs for treatment of paclitaxel-resistant anaplastic thyroid cancer
Authors: Fujita Tomoyuki , Sasaki Takayuki , Wang Zheng , Koshikawa Kayoko , Nishimura Hajime , Fujimori Minoru
Published: August 2015

Background: Anaplastic thyroid carcinoma (ATC) is a rare but particularly aggressive solid tumor that has a poor prognosis, despite multimodal treatment approaches. New chemotherapy agents are being developed and taxanes have efficacy against ATC. Targeted agents including fosbretabulin, imatinib, erlotinib and gefitinib have also been examined, but were unsuccessful. These results suggest that innovative strategies are required for treatment of ATC. Therefore, our primary aim was to determine the genes and pathways related to sensitivity to paclitaxel as biomarkers in ATC. Our secondary aim was to identify new genes and pathways as therapeutic targets in ATC.

Materials and Methods: We analyzed differences in gene expression profiles before and after treatment with paclitaxel in two ATC cell lines: KTA-3 cells, which are sensitive to paclitaxel, and TTA-2 cells, which are resistant to paclitaxel. Parametric Analysis of Gene Set Enrichment (PAGE) using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Transcriptional Regulatory Element Database (TRED) were performed to detect significant differences at the level of functional categories such as pathway genes and transcriptionally regulated genes.

Results: Genes in the Janus kinase/signal transducer and activator of transcription (JAK-STAT) pathway (KEGG classification) were downregulated significantly in KTA-3 cells compared with TTA-2 cells after treatment with paclitaxel. PAGE showed that breast cancer susceptibility gene (BRCA)1-related genes including Janus kinase (JAK)1, JAK2 and signal transducer and activator of transcription (STAT)3 were downregulated most significantly in KTA-3 cells compared with TTA-2 cells after paclitaxel treatment. Several JAK inhibitors inhibited cell growth in paclitaxel-resistant ATC cells.

Conclusions: JAK-STAT pathway may be a biomarker of paclitaxel sensitivity in ATC and may represent a new target in drug development for ATC therapy.

Citation Format: Tomoyuki Fujita, Takayuki Sasaki, Zheng Wang, Kayoko Koshikawa, Hajime Nishimura, Minoru Fujimori. JAK inhibitors as new drugs for treatment of paclitaxel-resistant anaplastic thyroid cancer. [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 2426. doi:10.1158/1538-7445.AM2015-2426
Abstract 2428: Translational study of F14512, a novel vectorised epipodophyllotoxin, which demonstrates a marked activity on ovarian cancer models from patients
Authors: Thibault Benoît , Zorza Gregoire , Meignan Samuel , Guilbaud Nicolas , Bailly Christian , Delord Jean-Pierre , Couderc Bettina , Kruczynski Anna , Ferre Pierre , Annereau Jean-Philippe
Published: August 2015

Epithelial ovarian cancer is the fourth cause of death among cancer-bearing women, frequently associated with carboplatin resistance, underlining the need of more efficient and targeted therapies. F14512 is a novel concept of drug vectorization that we propose here to investigate in ovarian cancer models. F14512 is an epipodophyllotoxin-core linked to a spermine chain, which enters selectively tumor cells via the polyamine transport system (PTS), currently in clinical phase II evaluation in AML. We compared the effects of F14512 versus etoposide against OVCAR-3, IGROV-1, SKOV-3, A2780S and A2780R cancer cell lines. Using the F17073 PTS fluorescent probe, we determined the PTS activity of these cells and of 18 clinical samples. As results, F14512 displayed strong anti-proliferative and pro-apoptotic activities in carboplatin-resistant models, being increased in cell lines with high levels of PTS. Consistently, at a dose of 1.25 mg/kg, F14512 significantly inhibited tumor growth in cisplatin-resistant SKOV-3 xenograft model. Interestingly, ex vivo analysis indicated that 15 patients sample out of 18 presented a higher F17073 fluorescent probe incorporation into CD326-positive tumor cells as compared to normal cells, even in the case of 2 platinum-refractory patients. Therefore, F14512 is a targeted drug with a potent anti-tumor efficacy regardless the status of cisplatin resistance. The high PTS activity detected in fresh clinical samples highlights the potential of F14512 as a new therapy for PTS-positive and platinum resistant ovarian cancer patients.

Citation Format: Benoît Thibault, Gregoire Zorza, Samuel Meignan, Nicolas Guilbaud, Christian Bailly, Jean-Pierre Delord, Bettina Couderc, Anna Kruczynski, Pierre Ferre, Jean-Philippe Annereau. Translational study of F14512, a novel vectorised epipodophyllotoxin, which demonstrates a marked activity on ovarian cancer models from patients. [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 2428. doi:10.1158/1538-7445.AM2015-2428
Abstract 2438: Identification of the mitochondrial binding site on the amino-terminal end of hexokinase II
Authors: Bryan Nadezda , Hwang Michelle M. , Raisch Kevin P.
Published: August 2015

Hexokinase II is responsible for the first step in the glycolysis pathway. Hexokinase II adds a phosphate onto the glucose molecule so it can proceed down the pathway to give the cancer cell energy for its continuous growth. Tumor cells overexpress the hexokinase II enzyme. In fact, it is the overexpression of the hexokinase II enzyme that makes the diagnosis of cancer possible when imaged by positron emission tomography (PET). Hexokinase II binds to the voltage-dependent anion channel (VDAC) on the mitochondrial membrane and when it is attached to the mitochondrial membrane it is blocking a major pathway for cell death. Thus, hexokinase II is responsible for two characteristics of cancer cells, rapid tumor growth and difficulty to kill. Therefore the overall goal of our laboratory is to identify novel compounds with the ability to displace or translocate hexokinase II from the mitochondrial membrane to the cytoplasm. To attain our goal, we propose to use the crystal structure of hexokinase II to create a molecular model of the enzyme. However the amino acids responsible for binding to VDAC are not known. Therefore, we made a series of truncations and point mutations to identify the binding site to VDAC. Truncations of the first 10 and 20 amino acids indicated that important amino acids for binding were located within the first 10 amino acids. We made a series of single, double and triple point mutations within the first 10 amino acids. Immunofluorescence and immunoblot data has confirmed that mutating the fifth amino acid from histidine to proline completely abolished binding to the mitochondrial membrane. To prepare hexokinase II for crystallization, we have cloned the enzyme downstream of a thrombin cleavage site and His-tag. We were able to purify hexokinase II using a cobalt column, then eluting hexokinase II using thrombin to cleave at the thrombin cleavage site. Purified hexokinase II is isolated after removal of the thrombin using Protein A beads. After the crystal structure of hexokinase II is obtained, we will use the University of Florida Structure-based Molecular Docking Core facility to identify compounds predicted to fit into the VDAC binding site. The compounds will be characterized to validate a mechanism-of-action of translocating hexokinase II from the mitochondrial membrane to the cytoplasm, blocking glycolysis and decreasing ATP synthesis. The positive compounds will be analyzed to determine the best strategy for moving our studies closer to clinical application in cancer patients.

Citation Format: Nadezda Bryan, Michelle M. Hwang, Kevin P. Raisch. Identification of the mitochondrial binding site on the amino-terminal end of hexokinase II. [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 2438. doi:10.1158/1538-7445.AM2015-2438
Abstract 2442: XPO1 is selinexor prime target: validation by mutating cysteine 528 on both XPO1 alleles using CRISPR/Cas9 genome editing
Authors: Neggers Jasper E. , Vercruysse Thomas , Jacquemyn Maarten , Vanstreels Els , Baloglu Erkan , Shacham Sharon , Crochiere Marsha , Senapedis William , Landesman Yosef , Daelemans Dirk
Published: August 2015

Human Exportin-1 (XPO1) is the key nuclear-cytoplasmic transport protein that exports a variety of different cargo proteins out of the cell's nucleus. Inhibition of XPO1-mediated protein export results in nuclear retention of cargo proteins including tumour suppressor proteins and is a novel therapeutic strategy for cancer. Selinexor, an orally bioavailable XPO1 inhibitor, effectively demonstrates potent activity against multiple types of cancer. Here we directly demonstrate the high selectivity of selinexor for XPO1 inside living cells.

Selinexor binds to the cargo-binding pocket of XPO1 and inhibits the formation of XPO1-cargo complex. The binding of selinexor to XPO1 involves a slowly reversible Michael addition type interaction of its acrylate moiety with cysteine 528 residue of XPO1. Using CRISPR/Cas9 genome editing we have now created a homozygous Jurkat T-ALL cell line carrying a Cys528Ser mutation in XPO1. This cell line was used to study the specificity of selinexor for XPO1 inside the cancer cell. Selinexor was highly toxic to wild-type Jurkat cells in the low nanomolar range while the mutant cells were resistant up to micromolar concentrations. These results were confirmed by resistance to induction of caspase dependent apoptosis as well as cell cycle arrest in mutant cells. The single Cys528Ser mutation thus confers resistance to selinexor. In addition, selinexor failed to accumulate cargo proteins in the nucleus of mutant cells. Moreover, the Cys528Ser substitution conferred resistance to the direct interaction of this drug to XPO1 in cells.

In conclusion, these results validate XPO1 as the selinexor's prime target and pinpoint its unique selectivity to the Cys528 residue of XPO1. Our findings also demonstrate the general utility of CRISPR/Cas9 genome editing for introducing point mutations in the genome of cancer cells for drug-target specificity validation.

Citation Format: Jasper E. Neggers, Thomas Vercruysse, Maarten Jacquemyn, Els Vanstreels, Erkan Baloglu, Sharon Shacham, Marsha Crochiere, William Senapedis, Yosef Landesman, Dirk Daelemans. XPO1 is selinexor prime target: validation by mutating cysteine 528 on both XPO1 alleles using CRISPR/Cas9 genome editing. [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 2442. doi:10.1158/1538-7445.AM2015-2442
Abstract 2456: The transmembrane domain of prostate specific membrane antigen: Deciphering the role of the Small-XXX-Small motif in oligomerization
Authors: Berg Brianna S. , Cook Brandan M. , Hyder Jack R. , Godfroy James I. , Yin Hubert , Saludes Jonel P.
Published: August 2015

Prostate cancer (PCa) is the second leading cause of cancer-related deaths among males in the United States. The prevalence of this disease and the benefits associated with early detection and treatment call for closer investigation into potential biomarkers and therapeutics targets. The high expression of the integral membrane protein called prostate specific membrane antigen (PSMA, EC 3.4.17.21) is implicated in PCa invasiveness as well as neovasculature metastasis of nonprostatic solid tumors. Little is known about the exact role of PSMA in PCa progression albeit it is one of the most validated biomarker for the diagnosis and detection of PCa. We have demonstrated that the isolated PSMA transmembrane domain (TMD) is capable of oligomerization under reducing gel electrophoresis conditions, interacting independently of extracellular domain dimerization. Following this discovery, we proceeded to determine the factor(s) responsible for its oligomerization. Since it is known that certain motifs are critical for TMD oligomerization of many transmembrane proteins, we hypothesized that the Small-XXX-Small motif in PSMA TMD may play a role in the oligomerization and subsequent activation of PSMA. Thus, to gain insight into the assembly of PSMA and the factors responsible for this assembly, we investigated if mutations at this TM motif will disrupt TM oligomerization. Our initial studies revealed that PSMA TMD has two repeat units of the Small-XXX-Small motif. This motif is known to be crucial in inducing a strong peptide self-assembly, analogous to the bitopic protein Glycophorin A. We synthesized the PSMA TMD mutant peptides using Biotage Alstra microwave peptide synthesizer, purified by high performance liquid chromatography, and characterized by MALDI-TOF mass spectrometry to establish homogeneity. SDS-PAGE gel shift assays revealed a direct correlation of oligomerization propensity and the presence of the motif, while motif knockdown led to observed loss of this property. ToxR reporter assay that qualitatively assesses relative TMD interactions revealed that oligomerization of PSMA TMD is ∼150% stronger than Glycophorin A. These findings will serve as a road map in the design of tight-binding exogenous anti-TMD peptides that target this oligomerization hot spot for possible diagnostic and therapeutic applications.

Citation Format: Brianna S. Berg, Brandan M. Cook, Jack R. Hyder, James I. Godfroy, Hubert Yin, Jonel P. Saludes. The transmembrane domain of prostate specific membrane antigen: Deciphering the role of the Small-XXX-Small motif in oligomerization. [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 2456. doi:10.1158/1538-7445.AM2015-2456
Abstract 2483: Met degradation by SAIT301, a Met monoclonal antibody, reduces the invasion and migration of nasopharyngeal cancer cells via inhibition of EGR-1 expression
Authors: Lee Bok-Soon , Kang Sam , Kim Kyung-Ah , Song Yun-Jeong , Cheong Kwang Ho , Cha Hyun-Young , Kim Haeng-Jun , Hwang Hye Sook , Kim Yeon Soo , Kim Chul-Ho
Published: August 2015

Nasopharyngeal carcinoma (NPC) is a common malignant tumor with high invasive and metastatic potential. The hepatocyte growth factor (HGF)-Met signaling pathway has a critical role in mediating the invasive growth of many different types of cancer, including head and neck squamous cell carcinoma. HGF also stimulates NPC cell growth and invasion in the cell line model.

In this study, we determined the inhibitory effect of Met, using a Met-targeting monoclonal antibody (SAIT301), on the invasive and growth potential of NPC cell lines. Met inhibition by SAIT301 resulted in highly significant inhibition of cell migration and invasion in both the HONE1 and HNE1 cell lines. In addition, we also found that co-treatment of SAIT301 and HGF decreased the anchorage-independent growth induced by HGF in HNE1 cell lines. After SAIT301 treatment, Met, together with its downstream signaling proteins, showed downregulation of p-Met and p-ERK, but not p-AKT, in both HONE1 and HNE1 cell lines. Interestingly, we found that HGF treatment of NPC cell lines induced early growth response protein (EGR-1) expression, which is involved in cell migration and invasion. In addition, co-treatment with SAIT301 and HGF inhibited the HGF-induced expression of EGR-1. Next, knockdown of EGR-1 using small-interfering RNA inhibited HGF-induced cell invasion in NPC cell lines, suggesting that the expression level of EGR-1 is important in HGF-induced cell invasion of NPC cells. Therefore, the results support that SAIT301 inhibited Met activation as well as the downstream EGR-1 expression and could have therapeutic potential in NPC. Taken together, we suggest that Met is an anticancer therapeutic target for NPC that warrants further investigation and clinical trials and SAIT301 may be a promising tool for NPC therapy.

Citation Format: Bok-Soon Lee, Sam Kang, Kyung-Ah Kim, Yun-Jeong Song, Kwang Ho Cheong, Hyun-Young Cha, Haeng-Jun Kim, Hye Sook Hwang, Yeon Soo Kim, Chul-Ho Kim. Met degradation by SAIT301, a Met monoclonal antibody, reduces the invasion and migration of nasopharyngeal cancer cells via inhibition of EGR-1 expression. [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 2483. doi:10.1158/1538-7445.AM2015-2483
Abstract 2485: Novel monoclonal antibody targeting cancer stem cells
Authors: Holderness Jeff , Turner Amy , dolezal Sam , Wolpe Steve , Pierce Michael , Gelber Cohava
Published: August 2015

Caerus Therapeutics (Caerus) is developing a monoclonal antibody directed to a cancer specific epitope on CD66c (CEACAM6) designated 109.12. CD66c has been shown in preclinical studies to be expressed on the colorectal cancer stem cell population but not on normal intestinal stem cells, making this a potential target for a therapeutic antibody. Previous attempts by other companies to develop anti-CD66c antibodies were unsuccessful due to cross-reactivity with CD66c on normal tissues. Caerus has developed a monoclonal antibody to a cancer-specific, glycan epitope that is only expressed in the adult during malignant transformation, enabling the targeting of CD66c on both cancer stem cells (CSCs) as well as bulk tumor without cross-reactivity with CD66c on normal cells. The glycan epitope recognized by the antibody has a novel structure not previously described that is highly protein-specific and site-specific. The specificity is due to a unique dual-recognition determinant for the site-specific glycosylation.

In addition to its expression on colorectal tumorspheres, the epitope recognized by the 109.12 antibody is expressed by a wide variety of cancers including colon, pancreatic, lung stomach and a subtype of breast cancer. The biological role of CD66c in malignancy and tumor dissemination is well documented; the specificity of the antibody for a CD66c epitope only expressed in malignant cells offers multiple opportunities for immunotherapy and diagnosis of a diverse spectrum of cancers.

Citation Format: Jeff Holderness, Amy Turner, Sam dolezal, Steve Wolpe, Michael Pierce, Cohava Gelber. Novel monoclonal antibody targeting cancer stem 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 2485. doi:10.1158/1538-7445.AM2015-2485
Abstract 2492: Eradication of breast cancer with bone metastasis by autologous formalin- fixed tumor vaccine (AFTV) and radiation
Authors: Kuranishi Fumito , Uemae Yoji , Ohno Tadao , Sumi Yusuke
Published: August 2015

INTRODUCTION) Bone-metastatic mammary carcinoma patients show the downhill course to a tragic ending despite of intensive chemo-radiation therapy, except an our case concomitantly treated with AFTV (AACR2013, World J Surg Oncol 2013; 11:127). We here report, as the second successful case, eradication of a large bone metastasis of advanced breast cancer after treatment with AFTV and radiation. (CASE) A 47-years old female with stage II breast cancer was operated in July, 2000. Left axillar recurrence was found 13 years later by ultrasonography and FNBC. PET scan revealed a huge bone metastasis in sternum. She was treated with radiation and AFTV (J Neurosurgery 2014;4:1) in Oct. - Nov. 2013. Follow-up PET (Sep. 2014) showed no hot spot, and we diagnosed the patient, complete remission.

(CONCLUSION) Complete remission of bone metastasis of mammary carcinoma is very rare. The initial successful case beared triple-negative breast cancer. Treatment with AFTV and radiation without intensive chemotherapy like the present case will be acceptable to any patient with bone-metastatic mammary carcinoma, though a large scale clinical trial should be required to confirm the therapeutic efficacy of AFTV.

Citation Format: Fumito Kuranishi, Yoji Uemae, Tadao Ohno, Yusuke Sumi. Eradication of breast cancer with bone metastasis by autologous formalin- fixed tumor vaccine (AFTV) and radiation. [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 2492. doi:10.1158/1538-7445.AM2015-2492
Abstract 2494: Vaccine-induced TNF alpha producing T cells synergize with cisplatin in tumor eradication
Authors: Melief Cornelis J. , van der Sluis Tetje C. , van der Burg Sjoerd H.
Published: August 2015

Previously we have shown that Synthetic Long Peptide (SLP) vaccination against Human Papilloma Virus (HPV) oncogenic proteins is safe and induces functional T-cell responses in mice and humans. Although vaccination induces potent clinical responses in mice and in patients with premalignant lesions, no clinical responses were observed in patients with cervical cancer. Here we show in a preclinical mouse model for HPV induced malignancies that SLP vaccination can be safely combined with clinically relevant chemotherapeutics to eradicate tumors. In mice that received either peptide vaccination or chemotherapy, only a temporary regression in tumor size was observed. Importantly, combined chemo-immunotherapy induced complete and sustained tumor eradication in nearly all mice. The chemotherapeutic agent cisplatin displayed the strongest synergy with SLP vaccination. Long term regression of tumors occurred at both the maximal tolerated dose of cisplatin and at 40% of that dose when combined with SLP vaccination, but at the later dose side effects such as body weight loss were absent. Upon vaccination tumors were highly infiltrated with Tumor Necrosis Factor alpha (TNFα) and Interferon gamma (IFN-γ) producing CD8+ CTLs. Tumor cells incubated with these cytokines and cisplatin in vitro strongly enhance their chemokine expression, compatible with the abundant leukocyte infiltration into the tumor upon combined chemo-immunotherapy. Accordingly, when combined with cisplatin treatment, SLP vaccine-induced CTLs appeared to migrate earlier from the tumor rim into the tumor beds. Moreover, analysis of the tumor cells in vivo showed that combined treatment significantly decreased the proliferative capacity of tumor cells compared to single treated or untreated tumors. Furthermore, we showed that TNFα enhanced cisplatin- induced, JNK dependent tumor cell apoptosis. This cell death was accompanied by an increased expression of pro-apoptotic molecules. The synergy between cisplatin and SLP vaccination was largely abolished by in vivo treatment with monoclonal antibody against TNFα. Together, our data show that combined peptide treatment with cisplatin leads to superior tumor eradication in the absence of T cell immunosuppression.

Citation Format: Cornelis J. Melief, Tetje C. van der Sluis, Sjoerd H. van der Burg. Vaccine-induced TNF alpha producing T cells synergize with cisplatin in tumor eradication. [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 2494. doi:10.1158/1538-7445.AM2015-2494
Abstract 2503: Efficient crosspresentation of oncofetal antigen (Glypican-3)-derived long peptides encompassing CTL and promiscuous Th cell epitopes using a novel liposome
Authors: Sayem Mohammad A. , Tomita Yusuke , Yuno Akira , Hirayama Masatoshi , Irie Atsushi , Tsukamoto Hirotake , Senju Satoru , Yuba Eiji , Yoshikawa Toshiaki , Kono Kenji , Nakatsura Tetsuya , Nishimura Yasuharu
Published: August 2015

Glypican-3 (GPC3), a human oncofetal antigen, is specifically overexpressed in hepatocellular carcinoma (HCC) and melanoma cells. GPC3-derived short peptides (SPs) vaccine carrying CTL epitopes were safe, and induced measurable immune and some clinical responses in a phase I clinical trial for treatment of HCC (Clin Cancer Res 18:3686, 2012). In this study we aim to identify GPC3-derived long peptides (LPs) carrying promiscuous HLA class II-binding Th1 cell epitopes. We predicted five candidate LPs using computer algorithm and proved antigenicity of all five GPC3-LPs to induce specific CD4+ T-cells by IFN-γ-ELISPOT assays. To determine the restriction HLA molecules involved in antigen presentation, blocking of antigen-induced IFN-γ production was investigated by adding anti-HLA-class II monoclonal antibodies (mAbs). Determination of specific restriction HLA molecules were carried out using L cells transfected with single pair of HLA class II α and β genes or allogeneic PBMC with shared HLA-class II molecule and found that these Th cells were restricted by seven frequent HLA class II molecules. Majority of these Th cell lines secreted Th1-type cytokines in response to autologous PBMCs pulsed with the cognate LPs. Th cells induced by four GPC3-LPs responded to autologous DCs pre-loaded with recombinant human GPC3 suggesting a possible natural processing of these LPs from GPC3 protein. One of the LPs was well cross-presented to GPC3-SP-specific CTLs when they were cocultured with DCs preloaded with GPC3-LPs encapsulated in a novel pH-sensitive liposome that can deliver LPs from endosome to cytoplasm. HLA-A2 transgenic mice immunized with the same LP showed increased GPC3-SP-specific and HLA-A2-restricted CTL response as compared to mice immunized with GPC3-SP alone. A part of this augmented response may be attributed to the help of CD4+ T cell response, because this LP stimulated specific mouse I-Ab-restricted CD4+ T cell response in vivo. GPC3-LPs-specific and HLA-Class II-restricted T cell responses were also observed in 12 out of 20 HCC patients vaccinated with GPC3-SPs. These GPC3-LPs may be applicable to immunotherapy of HCC.

Citation Format: Mohammad A. Sayem, Yusuke Tomita, Akira Yuno, Masatoshi Hirayama, Atsushi Irie, Hirotake Tsukamoto, Satoru Senju, Eiji Yuba, Toshiaki Yoshikawa, Kenji Kono, Tetsuya Nakatsura, Yasuharu Nishimura. Efficient crosspresentation of oncofetal antigen (Glypican-3)-derived long peptides encompassing CTL and promiscuous Th cell epitopes using a novel liposome. [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 2503. doi:10.1158/1538-7445.AM2015-2503
Abstract 251: Combining Ibrutinib with immune checkpoint blockade to induce therapeutic antitumor immune response in solid tumors
Authors: Sagiv-Barfi Idit , Kohrt Holbrook , Czerwinski Debra , Ng Patrick , Chang Betty , Levy Ronald
Published: August 2015

The ability of T-cell responses to effectively attack tumors is restricted by multiple negative checkpoint regulators. Monoclonal antibodies blocking negative regulators of T -cells, such as CTLA-4 and PD-L1 can amplify pre-existing immune responses and evoke new therapeutic responses. Ibrutinib (Imbruvica®), a covalent inhibitor of BTK has shown therapeutic efficacy in several blood cancers, by a mechanism thought to be a direct effect on a critical signaling pathway intrinsic to the malignant B cell. Since BTK is predominantly expressed in hematopoietic cells, solid tumors have not been an obvious target of this drug. An additional target of ibrutinib is the inhibition of ITK, a key enzyme in the survival of Th2 T cells. It has been reported that ibrutinib can alter the balance of Th1 and Th2 T cells leading to enhanced immune responses.

Here we report that the combination of ibrutinib and a-PD-L1 antibody suppresses tumor growth, reduces lung metastasis and improves survival of mice bearing solid tumors such as 4T1-triple negative breast cancer and CT26-colon cancer. Moreover, the combination of ibrutinib and a-PD-L1 was able to overcome ibrutinib resistance in mouse models of lymphoma and myeloma. We present evidence that the synergistic therapeutic activity of Ibrutinib with anti PD1 blockade results in enhanced T cell anti-tumor immune responses.

In preclinical models, by combining inhibitory checkpoint blockade while shifting the immune response towards CD4 Th1 with ibrutinib, immune tolerance to tumors can be overcome. These results provide rationale for several newly planned clinical trials combining ibrutinib with PD-1 blockade in solid tumor and exploration of such a combination in hematologic malignancies.

Citation Format: Idit Sagiv-Barfi, Holbrook Kohrt, Debra Czerwinski, Patrick Ng, Betty Chang, Ronald Levy. Combining Ibrutinib with immune checkpoint blockade to induce therapeutic antitumor immune response in solid tumors. [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 251. doi:10.1158/1538-7445.AM2015-251
Abstract 2511: Therapeutic dendritic cell targeting MIP3α-gp100 DNA vaccination with immunomodulatory αIL-10 and αPD-1 antibodies significantly enhances survival in a mouse melanoma model system
Authors: Gordy James , Markham Richard B.
Published: August 2015

The current study demonstrates that the combination of a DNA vaccine encoding the chemokine MIP-3α fused to melanoma antigen gp100 with immunomodulatory antibodies prolongs survival in a melanoma mouse model. The current studies utilize the B16F10 mouse spontaneous melanoma syngeneic transplantable mouse model system. Previous published work with this vaccine platform has indicated the MIP-3α component targets nascent peptides to immature dendritic cells leading to processing by class I and class II MHC pathways. It has further been shown in this tumor system that prophylactic vaccination with the DNA construct alone delayed tumor growth. Other studies have provided evidence that αPD-1 or αIL-10 neutralizing antibodies enhance immunological melanoma therapies by modulating the tolerogenic tumor microenvironment. First, this study expanded previous results by finding a significant decrease in tumor burden and increase in survival by prophylactic intramuscular electroporation [IM EP] of the DNA vaccine construct. Adding three therapeutic doses of αIL-10 given subcutaneously [subQ] at the tumor site to the treatment further increased mouse survival. The development of cell-mediated and humoral immune responses were documented for the first time in this system by Elispot and in-cell ELISA assays. Secondly, a novel therapeutic vaccination protocol was developed by initiating vaccination and antibody therapies after tumor challenge. With this therapeutic protocol, we demonstrated for the first time that vaccine significantly delays tumor burden and increases median survival from 17 to 21 days (p = 0.006). Addition of αIL-10 (subQ) and αPD-1 (intra-peritoneally) antibodies led to further highly significant decreases in tumor burden and increased median survival from 17 to 25 days (p = 0.0005). Efficient targeting of antigen to immature dendritic cells with a chemokine fusion vaccine offers a potential alternative approach to the ex vivo dendritic cell antigen loading protocols currently undergoing clinical investigation. Combining this approach with agents able to modulate the tolerogenic tumor microenvironment offers promise as a novel melanoma therapy.

Citation Format: James Gordy, Richard B. Markham. Therapeutic dendritic cell targeting MIP3α-gp100 DNA vaccination with immunomodulatory αIL-10 and αPD-1 antibodies significantly enhances survival in a mouse melanoma model system. [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 2511. doi:10.1158/1538-7445.AM2015-2511
Abstract 2513: Anti-tumor therapeutic effects in mice treated with Listeria monocytogenes (Lm)-LLO immunotherapy in combination with PD-L1
Authors: Molli Poonam , Wallecha Anu
Published: August 2015

Published reports have shown that Listeria monocytogenes (Lm) LLO immunotherapies can be combined with different cytotoxic modalities such as radiation, chemotherapy or immunotherapy for treatment of cancer. In a recent study, the combination of Lm-LLO immunotherapy (ADXS11-001) with an anti-PD-1 antibody significantly inhibited tumor growth and prolonged survival in animals. The combined treatment significantly increased the generation of antigen-specific immune responses in the periphery, and the infiltration of CD8 T cells into the tumor. These findings demonstrated that Lm-LLO immunotherapy combined with blocking of the PD-1/PD-L1 interaction was a feasible approach. The expression of PD-L1 by tumor cells serves as a protective function that can lead to suppression of tumor-infiltrating effector lymphocytes, thus allowing tumors to escape immune surveillance. We hypothesized that the combination of an Lm-LLO immunotherapy with an anti-PD-L1 antibody may potentially increase the therapeutic efficacy of either single agent alone and may be translatable to the clinical setting. To evaluate this hypothesis, a tumor regression study was initiated in a mouse model where established tumors were treated with ADXS11-001, PD-L1 antibody or combination ADXS11-001/PD-L1 antibody and tumor growth was monitored. In addition to tumor regression, serum samples were collected at different timepoints post-treatment to evaluate the changes in expression of various cytokines and chemokines using mouse inflammation map (Myriad RBM). The initial results indicated that the combination of ADXS11-001 and PD-L1 was better at controlling tumor growth kinetics than the single agent treatments. Serum cytokine analysis indicated treatment-related differences in the kinetics of cytokines and chemokines induced after single agent or combination treatments during different days of the study. Currently, we are evaluating the anti-tumor effects and immune responses generated in the periphery as well as in the tumor microenvironment. The results of this study will provide further insight as to the anti-tumor potential of combination of Lm-LLO immunotherapies with PD-1/PD-L1 specific antibodies.

Citation Format: Poonam Molli, Anu Wallecha. Anti-tumor therapeutic effects in mice treated with Listeria monocytogenes (Lm)-LLO immunotherapy in combination with PD-L1. [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 2513. doi:10.1158/1538-7445.AM2015-2513
Abstract 2515: Tumor presenting cells: a new strategy for cancer immunotherapy
Authors: Kreutz Fernando T.
Published: August 2015

Solid tumor cells as other non-immunological cells do not present MHC Class II. The MHC class II is a critical molecule responsible for peptide presentation to T helper cells. The presence of a not-self peptide on a MHC II molecule trigger the production of cytokines responsible for different steps on T cell expansion and maturation. Without the appropriate cytokine stimulation, cytotoxic T cells that identified a not-self peptide associate to a MHC class I molecules, may not proliferate or even be induce to anergy. We hypothesized that lack of anti-tumor immune responses on the majority of cancer patients (too little, too late) is due to a not appropriate MHC II peptide presentation. In our model, solid tumor cells (prostate cancer) are induce to express MHCII on their surface. In this novel approach of Cell Based Cancer Immunotherapy, patient's tumor cells were expanded in tissue culture and treated causing de novo expression of MHC II and activation of the MHC II peptide presentation pathway. Thus, the modified cancer cells are bifunctional, being capable of activating both helper T cells (MHC II) and cytotoxic T cells (MHCI), leading to cytokine production and a surprisingly robust and cancer-specific immune response. The modified solid tumor cell by itself will now behave as an antigen-presenting cell creating a Tumor Presenting Cell (TPC). As previous reported on a Phase IIb clinical trial done in Brazil (FK-Biotec/UFRGS/PUCRS), a population of local advance prostate cancer patients were treated with TPC. The study showed a significant (p = 0,03) increase in number of patients with undetectable levels of PSA (biochemical cure) after 5 years, 85% versus 48% on the control group. Also shown a trend of lowering mortality by prostate cancer, 9% in the threated group versus 19% in the control group. In conclusion, we are describing a novel Cell Based Cancer Immunotherapy that could be apply to several different tumor types.

Citation Format: Fernando T. Kreutz. Tumor presenting cells: a new strategy for cancer immunotherapy. [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 2515. doi:10.1158/1538-7445.AM2015-2515
Abstract 2517: Effects of toll-like receptor 4 agonist on the anti-tumor immune response to the GVAX vaccine
Authors: Korrer Michael J. , Bulte Jeff W.m. , Levitsky Hyam I.
Published: August 2015

We evaluated the immune response elicited by co-administration of a novel toll-like receptor 4 agonist, glucopyranosyl lipid A (GLA), with a genetically modified tumor cell based vaccine (GVAX) in mice. We have previously reported that the addition of GLA to the GVAX vaccine in mice resulted in a paradoxical decrease in delivery of tumor antigen to the draining lymph node, yet an increase in therapeutic benefit. The addition of GLA to GVAX altered the distribution of the vaccine induced anti-tumor T cell response. In mice vaccinated with GVAX + GLA adjuvant tumor-specific T cells accumulated in the spleen, liver and footpad as soon as two days following vaccination. In contrast, in mice vaccinated with GVAX alone, tumor-specific T cells accumulated primarily only in the dLN.

Since our previous study established that incorporation of GLA into the GVAX vaccine did not alter the magnitude of the anti-tumor T cell response, we set out to determine if the co-administration of GLA with GVAX altered the functional capabilities of the anti-tumor T cell response. We found that GLA did not increase in vivo tumor-specific cytotoxic activity or increase the number of anti-tumor interferon-γ expressing T cells found in the tumor or spleen following vaccination. We next determined if the addition of GLA to GVAX altered the kinetics of the anti-tumor T cell response. We found that the addition of GLA to the GVAX vaccine resulted in rapid accumulation of activated anti-tumor T cells in the spleen. Our results suggest that addition of GLA to the GVAX vaccine does not increase the magnitude or significantly improve functional capabilities of the anti-tumor immune response. These findings are consistent with the hypothesis that the addition of GLA to the GVAX vaccine increases therapeutic benefit by altering the distribution of the response, resulting in a more systemic anti-tumor immune response.

Citation Format: Michael J. Korrer, Jeff W.m. Bulte, Hyam I. Levitsky. Effects of toll-like receptor 4 agonist on the anti-tumor immune response to the GVAX vaccine. [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 2517. doi:10.1158/1538-7445.AM2015-2517
Abstract 2518: Effective vaccination against melanoma in an animal study: Combination of laser-assisted dermal skin delivery and cross-presenting XCR1+ dermal DCs targeting
Authors: Terhorst Dorothea , Fossum Even , Baranska Anna , Tamoutounour Samira , Malosse Camille , Garbani Mattia , Lechat Elmira , Crameri Reto , Winteler Roland , Bogen Bjarne , Malissen Bernard , Henri Sandrine
Published: August 2015

Background/Aim/Method

The induction of CD8+ cytotoxic T lymphocytes (CTL) is critical to eradicate tumor cells. In mouse skin, a subset of dendritic cell characterised by the expression of the chemokine receptor XCR1 is highly potent to activate CD8+ T cells. By combining PLEASE-assisted laser poration of the skin allowing dermal delivery and the use of dimeric vaccine molecule in which the XCR1 ligand, Xcl1, was fused to the antigen, we targeted specifically this XCR1+ dermal subset.

Results

Dermal delivery of this vaccine molecule after skin laser-poration induced specific strong T cell proliferation in an XCR1-dependent manner. A single immunization allowed protecting against melanoma in both therapeutic and prophylactic protocols.

Discussion & Conclusion

Thus, specific targeting of cross-presenting skin DCs represents a promising vaccine strategy for induction of CD8+ T cell responses and protection against cancers.

Citation Format: Dorothea Terhorst, Even Fossum, Anna Baranska, Samira Tamoutounour, Camille Malosse, Mattia Garbani, Elmira Lechat, Reto Crameri, Roland Winteler, Bjarne Bogen, Bernard Malissen, Sandrine Henri. Effective vaccination against melanoma in an animal study: Combination of laser-assisted dermal skin delivery and cross-presenting XCR1+ dermal DCs targeting. [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 2518. doi:10.1158/1538-7445.AM2015-2518
Abstract 2525: MLN4924 synergistically enhances cisplatin-induced cytotoxicity via JNK and Bcl-xL pathways in human urothelial carcinoma - In vitro and in vivo study
Authors: Ho I-Lin , Kuo Kuan-Lin , Chou Chien-Tso , Hsu Chen-Hsun , Pu Yeong-Shiau , Hsieh Ju-Ton , Huang Kuo-How
Published: August 2015

Introduction

Cisplatin-based chemotherapy is the main treatment for metastatic bladder urothelial carcinoma; however, the response rate is only approximately 40-65%. Many patients will encounter drug resistance to chemotherapy eventually. Therefore, combination therapies to enhance the efficacy of cisplatin and to overcome drug resistance are imperative for the treatment of urothelial carcinoma. The aim of this study was to investigate the antitumor effect and underlying mechanisms for the combination of cisplatin and MLN4924, a NEDD8-activating enzyme inhibitor, in human bladder urothelial carcinoma.

Materials & Methods

We used MTT assays and CalcuSyn software to calculate the combination index of cisplatin and MLN4924. The expression levels of DNA damage response regulators, apoptotic-related molecules, MAPK and Bcl-xL were revealed by western blot. c-Jun N-terminal kinase (JNK) inhibitor (SP600125) and overexpression of Bcl-xL were used to investigate the relationship between JNK and Bcl-xL. The in vitro findings were further confirmed in vivo via xenograft mouse model.

Results

The combination of cisplatin and MLN4924 exerted synergistic cytotoxicity on two high-grade bladder urothelial carcinoma cell lines, NTUB1 and T24 (combination index <1). In addition, MLN4924 potentiated cisplatin-induced apoptosis and activation of caspase-3, 7, phospho-histone H2A.X and PARP. We also observed c-Jun N-terminal kinase (JNK) activation with down-regulation of Bcl-xL during cisplatin and MLN4924 treatment. The inhibition of JNK activation partially restored cell viability as well as the expression of B-cell lymphoma-extra large (Bcl-xL); moreover, the overexpression of Bcl-xL rescued cell viability. In the in vivo study, MLN4924 significantly potentiated cisplatin-induced tumor suppression in urothelial carcinoma xenograft mice.

Conclusion

In summary, MLN4924 synergistically enhanced the antitumor effect of cisplatin through increasing DNA damage, JNK activation and down-regulating Bcl-xL in urothelial carcinoma cells. These findings provide a new therapeutiuc strategy for bladder cancer.

Citation Format: I-Lin Ho, Kuan-Lin Kuo, Chien-Tso Chou, Chen-Hsun Hsu, Yeong-Shiau Pu, Ju-Ton Hsieh, Kuo-How Huang. MLN4924 synergistically enhances cisplatin-induced cytotoxicity via JNK and Bcl-xL pathways in human urothelial carcinoma - In vitro and in vivo study. [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 2525. doi:10.1158/1538-7445.AM2015-2525
Abstract 2528: Vardenafil is superior to idarubicin in treatment of glioma
Authors: Ashour Abdelkader E. , Alzahrani Abdulrahman Z. , Abdel-Hamied Hala E. , Zoheir Khairy M. , Ahmed Sheikh F. , Al-Rejaie Salem S. , Abd-Allah Adel R.
Published: August 2015

Idarubicin (IDA) is a very potent second generation anthracycline that has shown high efficacy against glioma in vitro. However, this agent has failed to exert satisfactory therapeutic response in patients with brain tumors.

Phosphodiesterase (PDE-5), an enzyme which hydrolyzes intracellular cyclic guanosine monophosphate (cGMP), is highly expressed in many brain tumor cell lines. We proposed that increasing cGMP in the brain by the potent PDE-5 inhibitor vardenafil (VAR) will augment the antitumor efficacy of IDA against glioma. We also proposed that VAR will induce apoptosis of glioma cells. Here we show for the first time that VAR (10 mg/kg) enhanced the antitumor activity of IDA (0.1mg/kg). VAR alone inhibited tumor growth and prolonged survival of glioma bearing rats. Histopathological examination revealed that tumors from glioma bearing rats treated with VAR alone or VAR+ IDA presented a significant reduction in mitotic index, indicating less proliferative tumors, as compared to those which received PBS (control) or IDA. Real time PCR results demonstrated that VAR inhibited mRNA expression of PDE-5 in the brains of animals treated with VAR, compared to control-treated group, implicating an important role for the inhibition of PDE-5 in the antitumor activity of VAR. Interestingly, the antitumor activity of VAR was similar to that of IDA. Moreover, animals receiving either VAR alone or VAR+IDA demonstrated statistically significant improvement in overall survival when compared with control (PBS) or IDA groups. In order to explain such an unexpected finding, we examined the antiproliferative, pro-apoptotic and anti-invasive activities VAR in vitro. MTT assay results showed that VAR significantly inhibited the growth of rat C6 glioma cells. Annexin V propidium iodide assay results revealed that the inhibition of C6 cell growth is mediated at least in part by inducing C6 apoptosis. Wound healing and soft agar colony formation assays showed that VAR inhibited the migration and anchorage-independent growth of C6 cells, respectively. This suggests that the enhanced antitumor effect of VAR could be due to a combined antiproliferative, pro-apoptotic and anti-invasive activities.

Together, our data support anti-glioma properties of VAR, and provide a proof-of-concept basis for further development of VAR as potential adjuvant for treatment of brain tumors.

Citation Format: Abdelkader E. Ashour, Abdulrahman Z. Alzahrani, Hala E. Abdel-Hamied, Khairy M. Zoheir, Sheikh F. Ahmed, Salem S. Al-Rejaie, Adel R. Abd-Allah. Vardenafil is superior to idarubicin in treatment of glioma. [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 2528. doi:10.1158/1538-7445.AM2015-2528