bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5866: Discovery and profiling of a highly potent and selective ERK5 inhibitor: BAY-885
Authors: Lemos Clara , Nguyen Duy , Wortmann Lars , Bömer Ulf , Holton Simon , Lechner Christian , Prechtl Stefan , Sülzle Detlev , Siegel Franziska , Mumberg Dominik , Bauser Marcus , Hägebarth Andrea
Published: August 2018

ERK5 (Extracellular signal regulated kinase 5, also known as MAPK7, Gene ID: 5598) is a key integrator of cellular signal transduction and it has been shown to play a role in various cellular processes such as proliferation, differentiation, apoptosis and cell survival. Several studies have demonstrated that inhibition of ERK5 with siRNA or shRNA decreases proliferation and increases cell death in different tumor models, thereby highlighting the potential of ERK5 as a therapeutic target in cancer. By HTS and subsequent lead identification, we discovered a highly potent and selective ERK5 inhibitor, BAY-885, which was used to investigate the therapeutic potential of ERK5 in tumor cells displaying ERK5 genomic amplifications or with constitutive activation of the ERK5 pathway. BAY-885 inhibited ERK5 enzymatic activity with IC50 = 40 nM and was highly selective vs. 357 kinases (Eurofins panel). Inhibition by BAY-855 was confirmed in a cellular setting using a MEF2 reporter cell line (SN12C-MEF2-luc). The EGF-stimulated MEF2 transcriptional activity was strongly inhibited by BAY-885 (IC50 = 115 nM; IC90 = 691 nM). In contrast, the compound had no effect on a reporter cell line with constitutive luciferase expression (SN12C-CMV-luc, IC50 > 50 µM), thereby ruling out potential effects as a general inhibitor of transcription or translation. Importantly, despite its high potency, BAY-885 failed to inhibit the proliferation of cells with ERK5 genomic amplification (SN12C, SNU-449, MFM-223) or with constitutively active ERK5 signaling (BT-474, SK-BR-3). Altogether, our results demonstrate that inhibition of ERK5 kinase and transcriptional activity with a small molecule did not translate into antiproliferative activity in different relevant cell models, thus raising doubts as to the viability of ERK5 as a therapeutic target for anticancer drug development. The availability of potent and selective chemical probes, as the one described here, will contribute to further understanding the biology of ERK5 signaling in cancer.

Citation Format: Clara Lemos, Duy Nguyen, Lars Wortmann, Ulf Bömer, Simon Holton, Christian Lechner, Stefan Prechtl, Detlev Sülzle, Franziska Siegel, Dominik Mumberg, Marcus Bauser, Andrea Hägebarth. Discovery and profiling of a highly potent and selective ERK5 inhibitor: BAY-885 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5866.
Abstract 5869: TT-00420, a dual mechanism kinase inhibitor targeting both mitosis and tumor microenvironment, is highly active against TNBC both in vitro and in vivo
Authors: Peng Peng , Yang Xiaoju , Qiang Xiaoyan , Li Lin , Ni Shumao , Sun Xiaofen , Wu Di , Wu Frank
Published: August 2018

The hallmarks of cancer comprise dysregulated cell cycle and mitosis, active angiogenesis, tumor-promoting inflammation, and immune escape as well as other features. Therapeutic targeting one of the hallmarks has shown promising but short-lived efficacy in cancer therapy. Therefore, combination of two or more mechanisms holds great promise of next generation oncology drug development. Aurora kinase A and B are often over expressed in many malignancies and associated with poor prognosis. Several anti-angiogenesis agents have been approved alone or in combination with other oncology drugs. In addition to its role for tumor growth, recent studies illustrate that angiogenesis also plays critical roles in the complexity and dynamic regulation of tumor microenvironment (TME). With the rapid advancement of immune-oncology, several attractive targets involved in tumor-promoting inflammation and immune escape have emerged. We have focused our efforts on the discovery and development of small molecule kinase inhibitors with novel mechanisms to treat cancer. Kinase profiling showed that TT-00420, one of our leading compounds, inhibited Aurora A/B, RTKs involved in angiogenesis, and a few other targets directly involved in tumor-assocated inflammation and immune escape with low nano molar activities. In a screening of human breast cancer cell lines, TT-00420 was highly efficacious against triple negative breast cancer (TNBC) cells while leaving ER+ cells intact, which is completely complimentary to the activity of CDK4/6 inhibitors. This anti-TNBC activity was confirmed in a patient derived xenograft (PDX) TNBC model in vivo, in which TT-00420 was highly active both as first-line and second-line treatment. TT-00420 demonstrated good oral bioavailability and pharmacokinetic properties in mice, rats and dogs. 2-week repeated dose-range finding studies revealed mechanism-related but manageable toxicities of TT-00420 in the 3 species mentioned above. Its dual mechanism involving anti-mitosis and TME modulation will be discussed in this presentation. TT-00420 is now under active development for IND filings both in the US and China.

Citation Format: Peng Peng, Xiaoju Yang, Xiaoyan Qiang, Lin Li, Shumao Ni, Xiaofen Sun, Di Wu, Frank Wu. TT-00420, a dual mechanism kinase inhibitor targeting both mitosis and tumor microenvironment, is highly active against TNBC both in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5869.
Abstract 5891: ABCG2 expression contributes to CC-115 resistance
Authors: Beebe Jenny
Published: August 2018

Introduction: A major obstacle in the treatment of cancers is innate or acquired resistance. Multi-drug resistance proteins such as MDR1, ABCG2, MRP1, and LRP have been shown to be involved in resistance and are predictors of clinical outcomes. Expression of ABCG2, an ATP-binding cassette efflux transporter, may be responsible for observed variability of the efficacy of CC-115, a dual mTOR/DNA-PK inhibitor, currently in clinical trials. Here we evaluate the role of ABCG2 in CC-115 resistance.

Methods: Western blots, methylene blue and MTT assays, and FACS were used to determine ABCG2 expression, cell survival/viability with and without inhibitors, and accumulation of CC-115 respectively.

Results: MCF7/AdVp3000 (M3K) cells have been shown to have a significant increase in ABCG2 as compared to parental MCF7 cells. M3K cells had a 50-fold increase in IC50 to CC-115 compared to MCF7. Use of ABCG2 inhibitors FTC and C8 (1uM), decreased the IC50 of CC-115 in M3K cells by 10-fold. Accumulation studies using FACS showed that M3K cells had significantly lower accumulation of CC-115 as compared to MCF7 and addition of FTC and C8 (1uM) significantly enhanced accumulation of CC-115 to the same extent as seen in MCF7 cells. Next, HEK293/ABCG2 stable clone with overexpression of ectopic ABCG2 and its control HEK293/vec cells were used to determine ABCG2's direct impact on CC-115 resistance. HEK293/ABCG2 cells had a 10-fold increase in resistance to CC-115 with an IC50 of 2.05 uM as compared to 0.23 uM in HEK293/vec cells. Addition of FTC and C8 (1uM) decreased the IC50 by 10-fold in HEK293/ABCG2 cells. Accumulation of CC-115 in HEK293/ABCG2 cells was also significantly lower than that in HEK293/vec cells and addition of FTC and C8 (1uM) significantly increased its accumulation only in HEK293/ABCG2 cells.

Discussion: The results from this study suggest that ABCG2 contributes to and possibly is responsible for CC-115 resistance and that inhibiting ABCG2 could lead to reversal of CC-115 resistance, increased response rate, highlights the importance of personalized therapies, and has the potential to increase patient survival.

Citation Format: Jenny Beebe. ABCG2 expression contributes to CC-115 resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5891.
Abstract 59: 14-3-3zeta overexpressing breast cancer cells promote fibroblast senescence and CAF-like phenotype
Authors: Li Hongzhong , Xiao Yi , Yuan Xiangliang , Kuo Wenling , Li Ping , Yu Dihua
Published: August 2018

14-3-3ζ overexpression in breast cancer is associated with accelerated cancer progression and poor clinical outcome in patients. Our previous study revealed that 14-3-3ζ overexpression promotes epithelial mesenchymal transition (EMT) of breast cancer cells, which facilitates progression of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC). However, the impact of 14-3-3ζ overexpressing breast cancer cells on tumor microenvironment (TME) and the underlying mechanisms have not been explored. We found dramatically increased cancer associated fibroblast (CAF) signatures in patients' matched IDC lesions compared to their DCIS lesions, suggesting that activated fibroblasts may be involved in DCIS to IDC transition. Global gene expression profiling uncovered increased expression of pro-inflammatory cytokines/chemokines, including IL6 and IL8, in 14-3-3ζ AND ErbB2 co-overexpressed 10A.ErbB2.1433ζ cells compared to ErbB2 overexpressed 10A.ErbB2 cells. This finding was further confirmed by ELISA and validated in other breast cancer cell lines. We tested whether increased pro-inflammatory cytokines in the conditional medium (CM) from 14-3-3ζ overexpressed cancer cells promotes CAF-like phenotype. Indeed, CM from 14-3-3ζ overexpressed cancer cells significantly increased SMA+ activated fibroblast cells compared to controls. Additionally, up-regulation of β-galactosidase and reduced cell proliferation, hallmarks of senescence cells, were detected in fibroblast cells cultured in CM from 14-3-3ζ overexpressed cancer cells. Next, we explored potential mechanism of how 14-3-3ζ overexpression in cancer cells leads to up-regulation of pro-inflammatory cytokines/chemokines. Since NF-kappaB is one of the master upstream regulator of IL-6 and IL-8, we next investigated the NF-kappaB signaling activation in 14-3-3ζ overexpressed vs control cancer cells. 14-3-3ζ overexpressing cancer cells had hyperactive canonical NF-kappaB responses, including accelerated IκBα degradation, p65 phosphorylation, as well as nuclear translocation compared to 14-3-3ζ low cancer cells. Prolonged NF-kappaB signaling activation upon pro-inflammatory cytokine stimulation was also detected in 14-3-3ζ overexpressing cancer cells. These results suggest that 14-3-3ζ overexpressing cancer cells may promote fibroblast cell senescence and CAF-like phenotype by creating by a chronic inflammatory microenvironment, which ultimately enhances DCIS to IDC transition.

Citation Format: Hongzhong Li, Yi Xiao, Xiangliang Yuan, Wenling Kuo, Ping Li, Dihua Yu. 14-3-3zeta overexpressing breast cancer cells promote fibroblast senescence and CAF-like phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 59.
Abstract 707: Circulating immune profile in childhood neuroblastoma displays an activated response with simultaneous expression of checkpoint proteins by T cells and monocytes
Authors: Oliveira Flavia B. , Magalhães Luísa M. , Passos Livia S. , Neto Joaquim C. Aguirre , Dutra Álvaro P. , Martins Patricia R. , Salles Paulo G. Oliveira , Dutra Walderez O. , Gollob Kenneth J.
Published: August 2018

Neuroblastoma (NB) is a rare childhood cancer typically affecting children under five and arising from neural crest sympathoadrenal linage cells. Despite its rarity, it is the most frequent solid tumor in children under five. Determination of the circulating immune response in childhood NB before treatment has begun can help in the identification of potential cells and pathways involved in disease development and suitability for immunotherapy. These studies were designed to investigate the cellular and soluble immune response (cytokines) using flow cytometry with peripheral blood samples in a group of seven NB patients and four non-NB solid tumor patients between the age of 20-42 months. These data of the systemic immune response were compared to the intensity of tumor infiltrating lymphocytes and disease outcome after 18 months of treatment. Analysis of peripheral blood cellular immune status revealed that the NB group displayed an increase in the frequency of effector memory T cells (p <0.05), as well as an increase in the expression of inhibitory molecules CTLA-4 and PD-1 by CD4 + T lymphocytes (p < 0.05), and CTLA-4 by CD8+ T cells (p <0.06). Moreover, an increase in PD-L2 was seen on transitional (CD14+CD16+) and non-classical (CD14-CD16+) monocytes from NB (p <0.05). Further studies analyzing circulating cytokines (IL-2, 4, 5, 6, 9, 10, 13, 17A, 17F, 21, 22, IFN-gamma and TNF-alpha) in the plasma of the same patients showed an overall pattern of increased cytokines from the NB group as compared to the control group with increased IL-5, IL-6, IL-9 and IL-10 (p < 0.10). Lastly, the NB group showed an intense tumor infiltrating lymphocyte response in both the septa region and tumor nests, which was correlated with circulating TNF-alpha levels (R2 = 0.82, p = 0.06). Overall these findings of the systemic immune response in this rare childhood cancer indicate an active immune response with profiles consistent with both a down modulatory response and an overall activated profile based on soluble cytokines and tumor infiltrating lymphocyte intensity. These findings point to a systemic immune-modulation profile of the cellular response associated with NB disease.

Citation Format: Flavia B. Oliveira, Luísa M. Magalhães, Livia S. Passos, Joaquim C. Aguirre Neto, Álvaro P. Dutra, Patricia R. Martins, Paulo G. Oliveira Salles, Walderez O. Dutra, Kenneth J. Gollob. Circulating immune profile in childhood neuroblastoma displays an activated response with simultaneous expression of checkpoint proteins by T cells and monocytes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 707.
Abstract 748: Non-internalizing site-specific antibody-drug conjugates based on maytansinoids display curative properties
Authors: Sala Gianluca , Capone Emily , Piccolo Enza , Ponziani Sara , Gentile Roberta , Ippoliti Rodolfo , Giansanti Francesco , Iacobelli Stefano
Published: August 2018

Antibody-Drug Conjugates (ADCs) are highly potent biopharmaceuticals that use the targeting ability of monoclonal antibodies to selectively bind to tumor cells where the conjugated cancer drug is released. Traditionally, the anticancer efficacy of ADCs relies on their selective internalization by cancer cells. However, it has recently been shown that non-internalizing, linkerless ADCs targeting the tumor extracellular environment can display a potent therapeutic activity. LGALS3BP (aka Mac-2 BP or 90K) represents an appealing target for non-internalizing ADC development, as the protein is largely secreted by the majority of human tumors, while being virtually undetectable in normal adult tissues except for the prostate and the colorectum. Additionally, once secreted the protein stops from spreading and clusters on the plasma membrane where it binds to some endogenous ligands. Here, we show that an engineered variant of the humanized 1959 antibody to human LGALS3BP selectively localizes around the tumor cells and once site-specifically coupled to the maytansinoid drugs DM3 or DM4 by means of disulfide linker can display a potent therapeutic activity. Both the 1959sss-DM3 and -DM4 conjugates mediated potent antitumor activity in mice bearing human tumor xenografts. Quantitative biodistribution studies confirmed a preferential accumulation of 1959sss-DM3 and -DM4 conjugates around the tumor cells. Notably, we found that both conjugates were well tolerated and cured 100% of tumor-bearing mice. Our findings offer a preclinical proof-of-concept for curative non-internalizing ADC endowed with an innovative mechanism of action.

Citation Format: Gianluca Sala, Emily Capone, Enza Piccolo, Sara Ponziani, Roberta Gentile, Rodolfo Ippoliti, Francesco Giansanti, Stefano Iacobelli. Non-internalizing site-specific antibody-drug conjugates based on maytansinoids display curative properties [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 748.
Abstract 754: Unique pharmacologic properties of Dolaflexin-based ADCs—a controlled bystander effect
Authors: Clardy Susan M. , Yurkovetskiy Alex , Yin Mao , Gumerov Dmitry , Xu Ling , Ter-Ovanesyan Elena , Bu Charlie , Johnson Alex , Protopopova Marina , Zhang Qingxiu , Bodyak Natalya , Damelin Marc , Lee David H. , Bergstrom Donald , Lowinger Timothy B.
Published: August 2018

Antibody-drug conjugates (ADCs) are designed to bind tumor-associated antigens and deliver conjugated cytotoxic payloads to antigen-positive cells. Some ADCs also kill neighboring cells (including antigen-negative cells) by a mechanism referred to as the bystander effect. This effect can be beneficial when the antigen has heterogeneous expression among cells in a solid tumor, but it can also increase off-target toxicity of ADCs. Herein, we report on a unique pharmacologic property of the Dolaflexin platform, which provides a controlled bystander effect that retains the benefits of the bystander effect with respect to antitumor cytotoxicity but reduces the off-target toxicity. The controlled bystander effect, termed “Dolalock,” was achieved through design of a payload, auristatin F-hydroxypropylamide (AF-HPA), that is membrane-permeable and capable of bystander killing but is further catabolized to membrane-impermeable auristatin F (AF). This catabolism of the payload “locks” the highly potent AF in the cell. Using Dolaflexin-based ADCs, we investigated the extent of intracellular AF-HPA and AF release, tumor cell retention and bystander activities in vitro and in vivo. We observed both auristatin species within cells. Co-culture assays with HER2-positive and HER2-negative cells confirmed the cell permeability and bystander-killing capabilities of AF-HPA released from a Dolaflexin-based ADC. Biodistribution studies of Dolaflexin-based ADCs revealed time-dependent concentrations of AF-HPA and AF as well as significant accumulation of AF in xenografted tumor cells, consistent with the Dolalock mechanism. An additional benefit of AF formation was seen in multidrug-resistant transporter studies, which demonstrate that AF, in contrast to AF-HPA, is not a P-glycoprotein 1 (Pgp) substrate. This property may offer additional benefit in Pgp-expressing tumors. In summary, we have shown that the novel AF-HPA payload used in the Dolaflexin platform allows for a controlled bystander effect that likely contributes to the enhanced efficacy and lack of neutropenia we have observed with Dolaflexin-based ADCs.

Citation Format: Susan M. Clardy, Alex Yurkovetskiy, Mao Yin, Dmitry Gumerov, Ling Xu, Elena Ter-Ovanesyan, Charlie Bu, Alex Johnson, Marina Protopopova, Qingxiu Zhang, Natalya Bodyak, Marc Damelin, David H. Lee, Donald Bergstrom, Timothy B. Lowinger. Unique pharmacologic properties of Dolaflexin-based ADCs—a controlled bystander effect [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 754.
Abstract 784: NCI CPTAC phase III, proteogenomic analysis of 10 cancers
Authors: Thiagarajan Mathangi
Published: August 2018

The National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium (CPTAC) is an international effort to accelerate the understanding of the molecular basis of cancer through the application of large-scale proteomic and genomic analysis, or proteogenomics. Leidos Biomedical Research, a prime contractor to NCI, provides a robust infrastructure for supporting the collection and sequencing of high-quality biospecimens and data, in addition to project and subcontract management for this program. CPTAC applies the understanding of the molecular basis of cancer to identify biomarker candidates. CPTAC phase III began late 2016 to collect and analyze 200 cases of each of ten additional cancers. The cancers include sarcoma, pancreatic ductal adenocarcinoma, head and neck squamous cell carcinoma, lung adenocarcinoma, lung squamous cell carcinoma, uterine corpus endometrial carcinoma, clear cell renal cell carcinoma, glioblastoma multiforme, and acute myeloid leukemia. The program completed the discovery phase collection of 100 cases for 3 tumor types in the first year. The study entails collection and pathology evaluation of biospecimens, high-quality clinical data and images from clinical sites around the world. A biorepository evaluates and processes the biospecimens, sending nucleic acids to sequencing centers and tissues to proteomics groups. Data are combined and analyzed by proteogenomic data analysis and translational centers. Genomic data are made available to the research community through the NCI Genomic Data Commons. Proteomic and proteogenomic data are made available through the Data Coordinating Center. Imaging data are made available through NCI imaging archive. We report here on progress in collection of tissues and clinical data, the preliminary analysis trends and the integration of biorepository, proteomics and genomics and analysis centers.

Citation Format: Mathangi Thiagarajan. NCI CPTAC phase III, proteogenomic analysis of 10 cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 784.
Abstract 795: Isatin analog for the treatment of acute myeloid leukemia
Authors: Gowda Krishne , Annageldiyev Charyguly , Desai Dhimant , Amin Shantu , Claxton David , Sharma Arati
Published: August 2018

Acute myeloid leukemia (AML) is a heterogeneous disease with therapeutic modalities relying on traditional cytotoxic therapies and hematopoietic stem cell transplantation. Current first-line cytotoxic chemotherapy exhibits limited success, with 50% of younger patients and 80% of older patients succumbing to the disease. There is an urgent unmet need for new therapeutics in acute myeloid leukemia (AML) as standard therapy has not changed in the past three decades and outcome remains poor for most patients. Our group has reported cytotoxic potential of dibromo-derivative of isatin, 5,7-dibromo-N-(p-thiocyanomethylbenzyl)isatin (KS99) against variety of solid tumors and multiple myeloma (MM) cells by inhibiting BTK, AKT and tubulin polymerization. In this study, we examined the ability of KS99, to inhibit the growth of panel of human AML cell lines and primary samples collected from AML patients. After 48h exposure, KS99 inhibited the growth of AML cell lines (IC50, 150-225nM) and primary blast samples (IC50, 600-1300nM) in a dose dependent manner. KS99 treatment also selectively reduced the clonogenicity of human acute myeloid leukemia patient cells compared to the hematopoietic stem cells. We also found that KS99 induced apoptosis by modulating expression of Mcl-1 and Bcl-2. Further studies will aim to determine the mechanism of action of KS99 and as a single agent and in combination with anti-leukemia agents and demonstrate the preclinical efficacy in AML animal models including AML patient derived xenografts. Together, these data demonstrate the therapeutic efficacy of Isatin analog and suggest that KS99 should be further developed as a novel therapeutic agent for AML.

Citation Format: Krishne Gowda, Charyguly Annageldiyev, Dhimant Desai, Shantu Amin, David Claxton, Arati Sharma. Isatin analog for the treatment of acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 795.
Abstract 995: Tumor-stroma IL-1β-IRAK4 feedforward circuitry drives tumor fibrosis, chemo-resistance and is associated with poor prognosis in pancreatic cancer
Authors: Zhang Daoxiang , Li Lin , Jiang Hongmei , Wang-Gillam Andrea , Yu Jinsheng , Head Richard , Liu Jingxia , Ruzinova Marianna B , Lim Kian-Huat
Published: August 2018

Targeting the desmoplastic stroma of pancreatic ductal adenocarcinoma (PDAC) holds promise to augment the effect of chemotherapy, but so far success remains limited in the clinic. Furthermore, preclinical mouse models suggest that near-depletion of cancer-associated fibroblasts (CAFs) carries a risk of accelerating PDAC progression. These concerns underscore the need to concurrently target the key signaling mechanisms that drive the malignant attributes of both CAFs and PDAC cells. We previously reported that inhibition of Interleukin-1 Receptor Associated Kinase 4 (IRAK4) suppresses NF-kB activity and promotes chemotherapy response in PDAC cells. In this study, we show that CAFs in PDAC tumors robustly express activated IRAK4 and NF-kb. The role of IRAK4 and NF-kB in PDAC CAFs has not been reported, and should be clarified before advancing IRAK4 inhibitors to the clinic. Using shRNAs and small molecular inhibitors, we found that IRAK4 is a key driver of NF-kB activity in CAFs. We showed that CAFs utilizes IRAK4 to drive tumor fibrosis, support PDAC cells proliferation, survival and chemo-resistance in vitro and in vivo. From cytokine array analysis of CAFs and microarray analysis of PDAC cells, we identified IL-1b as a key cytokine that activates IRAK4 in CAFs. Targeting IRAK4 or IL-1b renders PDAC tumors less fibrotic and more sensitive to gemcitabine in vivo.Moreover, high IL-1b expression by immunohistochemistry in PDAC samples is strongly associated with poor overall survival. Together, our studies established a tumor-stroma IL-1b-IRAK4 feedforward circuitry that can be therapeutically disrupted to render chemotherapy more effective in PDAC.

Citation Format: Daoxiang Zhang, Lin Li, Hongmei Jiang, Andrea Wang-Gillam, Jinsheng Yu, Richard Head, Jingxia Liu, Marianna B Ruzinova, Kian-Huat Lim. Tumor-stroma IL-1β-IRAK4 feedforward circuitry drives tumor fibrosis, chemo-resistance and is associated with poor prognosis in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 995.
Abstract CT019: ASN003, a novel highly selective BRAF and PI3K dual inhibitor: Phase I PK/PD results in patients with advanced solid tumors
Authors: Rasco Drew , Lakhani Nehal , Sullivan Ryan , Mita Monica , Shah Jaimini , Usansky Helen , Reddy Sanjeeva , Rao Niranjan S. , Toker Sarper , Denis Louis , Flaherty Keith , Tolcher Anthony
Published: August 2018

Background RAS-RAF-MEK and PI3K-AKT-mTOR are two major pathways involved in tumor cell signaling and growth. Components of these pathways are frequently mutated in a broad range of tumors. ASN003 is a highly selective and potent (low nM IC50) inhibitor of BRAF and PI3K-α and -δ. ASN003 shows strong antitumor activity in tumor models harboring BRAF and PIK3CA mutations, and also in patient-derived xenograft (PDX) models that are resistant to selective BRAF and MEK inhibitors.

Patients and Methods: Oral once-daily ASN003 is being evaluated for safety/tolerability and preliminary efficacy in eligible patients with advanced solid tumors using an accelerated dose titration design (Part A) and enrolling cohorts of patients diagnosed with melanoma, CRC, NSCLC and other solid tumors with a BRAF, PIK3CA mutations at MTD (Part B). Pharmacokinetic (PK) profile and the pharmacodynamic (PD) effects of ASN003 on tumor tissue biomarkers such as pERK and pS6 are being investigated in both parts of the study.

Results: Patient accrual in Part A is ongoing. As of January 2018, fifteen eligible patients were enrolled in dose levels ranging from 10 - 400 mg QD and 400 mg BID. ASN003 has been well tolerated. Treatment-related adverse events (TRAEs) were mostly mild (G1) to moderate (G2). TRAEs include, rash (G3), hypersensitivity (G3) (n=1), diarrhea (G2) (n=1), hyperglycemia (G2) (n=1), rash maculo-papular (G2) (n=1), vomiting (G1) (n=3), nausea (G1) (n=2), hyperglycemia (G1) (n=2), and dry mouth/lips/skin, transient blurred vision, rash acneiform, ALT increase, cognitive disturbance and hyperkalemia. The PK profile showed dose-dependent increase in systemic exposure at steady state (Cmax up to 5,990 ng/mL, AUC0-T up to 110,000 ng.h/mL) and a half-life of 14-25 hours in general. Early evidence of biomarker changes in repeat biopsies, and clinical disease control have been observed.

Conclusions: ASN003 is a novel small molecule, with uniquely selective and potent inhibition of BRAF, PI3K-α and -δ kinases. To date, ASN003 was well tolerated at doses up to 400 mg QD/BID and achieved good systemic exposure. Updated and detailed clinical safety/efficacy and PK/PD results will be presented.

Citation Format: Drew Rasco, Nehal Lakhani, Ryan Sullivan, Monica Mita, Jaimini Shah, Helen Usansky, Sanjeeva Reddy, Niranjan S. Rao, Sarper Toker, Louis Denis, Keith Flaherty, Anthony Tolcher. ASN003, a novel highly selective BRAF and PI3K dual inhibitor: Phase I PK/PD results in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT019.
Abstract CT056: The first-in-human clinical trial of MG7-CART for metastasis colon cancer
Authors: Yuan Jijun
Published: August 2018

MG7 antigen, a highly glycosylated CEACAM5 molecule, is specifically expressed in human gastrointestinal cancers. An MG7-CART therapy has been developed and showed great efficacy in gastric cancer PDX model. Here we present the first-in-human clinical trial results of MG7-CART therapy for metastasis colon cancer treatment.

Distal metastasis was observed in pelvic cavity, peritoneal, spleen, liver and uterus after the patient received 6 rounds of bevacizumab plus EXLOX treatments. Intratumoral injections of MG7-CART (1-1.2x107/site) were given to the patient sequentially in peritoneal, spleen and uterus metastasis and two rounds of intravenous injections of MG7-CART (1x107 to 1.5x108) were given at the same time.

Over 80% tumor necrosis could be observed in peritoneal and liver metastasis 40 days after injection and MG7-CART cell expansion could also be detected by PCR. During the treatment, the patient experienced transient body temperature increase and cytokine release.

The first-in-human clinical trial result showed that MG7-CART therapy is efficacious and safe with no observed adverse effects.

Citation Format: Jijun Yuan. The first-in-human clinical trial of MG7-CART for metastasis colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT056.
Abstract CT067: A phase Ib study of Toca 511, a retroviral replicating vector, followed by Toca FC in patients with advanced cancer
Authors: Merchan Jaime , Rodon Jordi , Falchook Gerald , Venkat Shree , Ostertag Derek , Tejera Dalissa , Kheoh Thian , Jolly Douglas J. , Gruber Harry E. , Shorr Jolene S.
Published: August 2018

Toca 511 (vocimagene amiretrorepvec) is an investigational, conditionally lytic retroviral replicating vector (RRV) that selectively infects cancer cells. Toca 511 spreads through tumors, stably delivering an optimized cytosine deaminase (CD) gene that converts the prodrug, Toca FC (investigational, extended-release 5-FC), into 5-FU. Based on preclinical studies, 5-FU kills infected dividing cancer cells and diffuses and kills surrounding cancer cells, myeloid derived suppressor cells, and tumor associated macrophages, thus reestablishing tumor immunity. In a previous Phase 1 study, intravenous (IV) injection of Toca 511 successfully delivered and expressed CD protein to high grade glioma tumors. In animal models of metastatic colorectal cancer, IV Toca 511 infected metastatic sites, and subsequent 5-FC treatment resulted in decreased tumor size and improved survival. Toca 6 is a Phase 1b, multicenter, open-label study in patients with advanced solid tumors or lymphoma (NCT02576665) designed to investigate changes in immune activity after treatment with Toca 511 & Toca FC. Vector deposition and transgene expression in tumor tissue following IV delivery of Toca 511 also is followed. Toca 511 is injected IV daily for 3 days, with subsequent injection either intratumorally after biopsy or, in the brain tumor setting, into resection cavity walls following resection. Oral Toca FC is started approximately 4 weeks later and repeated every 4-6 weeks. A total of 30 patients are planned to be enrolled. In patients treated to date, viral RNA, DNA, and CD protein expression after IV Toca 511 delivery have been detected in liver metastases from colorectal cancer and mesenteric lymph node metastases from pancreas cancer, demonstrating IV delivery of virus to and transgene expression in tumor. Preliminary data indicate treatment has been generally well tolerated to date, with few related adverse events. Data on changes from baseline in immune activity in tumor (infiltrating T-cell subpopulations, B cells, monocytes) and peripheral blood (effector, memory, Treg, and myeloid lineage cells), viral and CD protein expression in tumor, and safety will be presented.

Citation Format: Jaime Merchan, Jordi Rodon, Gerald Falchook, Shree Venkat, Derek Ostertag, Dalissa Tejera, Thian Kheoh, Douglas J. Jolly, Harry E. Gruber, Jolene S. Shorr. A phase Ib study of Toca 511, a retroviral replicating vector, followed by Toca FC in patients with advanced cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT067.
Abstract LB-018: ARQ 531, a novel and reversible inhibitor of Bruton's tyrosine kinase, displays favorable oral bioavailability and exposure in patients with B-cell malignancies
Authors: Hall Terence , Yu Yi , Eathiraj Sudharshan , Stephens Deborah , Flinn Ian , Woyach Jennifer , Schwartz Brian , Savage Ronald E.
Published: August 2018

Background: ARQ 531 is a novel, ATP competitive reversible inhibitor Bruton's tyrosine kinase (BTK). BTK is a key regulator of the B cell receptor (BCR) signaling pathway that mediates signaling from the cell surface to the cytoplasm and into the nucleus. ARQ 531 is not metabolized by any of the major drug metabolizing CYP450 enzymes. Here we report pharmacokinetic profile of ARQ 531 in a phase I study evaluating safety, pharmacokinetics and pharmacodynamics activity and clinical activity of ARQ 531 in selected subjects with relapsed/refractory B-cell malignancies. Preclinical studies in rats, dogs and monkeys are also described.

Methods: Oral and intravenous single dose pharmacokinetic studies of ARQ 531 were conducted in rats, dogs, and monkeys to determine oral bioavailability and drug exposure. In a standard ‘3+3' dose-escalation study design, ARQ 531 was given orally once per day beginning at 5 mg/dose and escalating for 4 weeks [NCT03162536]. Plasma samples were collected to determine ARQ 531 concentrations and whole blood / PBMCx to quantify pBTK inhibition. Plasma samples from each species were analyzed by liquid chromatography-mass spectrometry/ mass spectrometry (LC-MS/MS).

Results: Consistent with preclinical studies, patients enrolled in the phase I study showed favorable exposures, the steady state peak to trough ratio was generally 3:1 or lower. ARQ 531 had an elimination half-life at steady state of ~24 hr and Cmax occurred 2 to 3 hours after dosing. Pharmacodynamic changes included suppression of BTK phosphorylation. No drug related AEs or DLTs have been observed thus far in the study.

Conclusions: ARQ 531 demonstrates a favorable PK profile in humans supporting once daily dosing. Sufficient plasma levels are attained and high levels of pBTK inhibition in peripheral blood can be achieved following oral dosing. Additional dose and schedule evaluations continue, and updated clinical and biomarker results will be presented.

Citation Format: Terence Hall, Yi Yu, Sudharshan Eathiraj, Deborah Stephens, Ian Flinn, Jennifer Woyach, Brian Schwartz, Ronald E. Savage. ARQ 531, a novel and reversible inhibitor of Bruton's tyrosine kinase, displays favorable oral bioavailability and exposure in patients with B-cell malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-018.
Abstract LB-045: Iron depletion suppress the stemness markers and functions of cancer stem cells
Authors: Ohara Toshiaki , Katsura Yuki , Noma Kazuhiro , Narusaka Toru , Kato Takuya , Sato Hiroaki , Komoto Satoshi , Tomono Yasuko , Ninomiya Takayuki , Tazawa Hiroshi , Kagawa Shunsuke , Shirakawa Yasuhiro , Fujiwara Toshiyoshi
Published: August 2018

Background: Cancer stem cells (CSCs) have been proposed to be responsible for tumor initiating, drug resistance, metastasis, and recurrence. Although CSCs are considered to be important targets therapeutically, clinically effective CSC targeting strategies have not yet been established. Iron plays an important role in critical cellular processes, such as energy production and DNA synthesis. Although adequate iron levels are essential for human health, iron overload is known to cause some types of cancer. CSCs are considered to be involved in the tumor regardless of early stage. Thus we have focused on the relationship between iron and CSCs. We previously reported that the expression of stemness markers was suppressed by iron chelator in miPS and miPS inducible CSC model cells (miPS-LLCcm). Here, we hypothesized that the expression of stemness markers and function were also suppressed by iron chelator in high malignant cancer cells with stemness potential.

Method: We used 4 stemness markers expressing cancer cell lines (HSC-2: Oral squamous cancer, TE-4 and OE33: Esophageal cancer, and NT-2: Embryonal cell carcinoma). Deferasirox (DFX), an oral iron chelator, was used. The stemness markers expression including Nanog, Sox2, Oct3/4, Klf-4 and c-Myc was examined by western blot analysis. Self-renewal ability was examined by sphere formation assay. Anti-proliferative effect of DFX was assessed combined with CDDP using HSC-2 cells.

Result: DFX suppressed the expression of stemness markers and sphere formation ability in 4 cancer cell lines. In contrast, CDDP could not suppressed them. In HSC-2 cells, combination therapy with CDDP and DFX synergistically suppressed the proliferation with suppression of stemness markers.

Conclusion: Our results indicated that iron depletion generally suppressed the stemness markers and functions of high malignant cells same as miPS and miPS-LLCcm. Thus iron depletion can be a novel therapy for CSCs via suppression of CSCs function.

Citation Format: Toshiaki Ohara, Yuki Katsura, Kazuhiro Noma, Toru Narusaka, Takuya Kato, Hiroaki Sato, Satoshi Komoto, Yasuko Tomono, Takayuki Ninomiya, Hiroshi Tazawa, Shunsuke Kagawa, Yasuhiro Shirakawa, Toshiyoshi Fujiwara. Iron depletion suppress the stemness markers and functions of cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-045.
Abstract LB-106: Allorepertoire-derived HLA class I/peptide-specific T cell receptor transgenic CD4+ T cells mediate antitumor responses in Ewing sarcoma mimicking allo-rejection
Authors: Schober Sebastian J. , Thiede Melanie , Schirmer David , Wohlleber Dirk , Richter Guenther , Busch Dirk H. , Thiel Uwe , Burdach Stefan E.
Published: August 2018

Introduction: Innovative therapies are urgently warranted to cure patients with advanced Ewing sarcoma (ES). Specific cellular-based approaches for immunotherapy of solid cancers show promising results in first clinical trials. Mostly, CD8+ effector T cells are genetically modified to recognize and kill tumor cells. In organ transplantation, alloreactive CD4+ T helper 1 cells have shown to be an underestimated key player in allo-rejection.

In previous works we observed massive CD4+ cell tissue-infiltration in tumor-free Rag2-/-c-/- mice after adoptive transfer of ES-specific CD8+ T cells combined with peripheral mononuclear cells in tumor bearing mice, suggesting an important role of CD4+ cells in disease control. In this study we transduce CD4+ T cells from healthy donors with an HLA class I allorepertoire-derived TCR specific for the ES-associated antigen STEAP1130 for which in vivo ES control by adoptively transferring CD8+ cells with the same transgene was demonstrated in previous works.

Methods: STEAP1/HLA-A*02:01 specific TCR transgenic CD4+ T cells were generated and characterized by flow cytometry, interferon-, granzyme-B release and xCelligence assays to study direct cytotoxicity and tumor growth inhibition, in comparison to STEAP1/HLA-A*02:01 specific TCR transgenic CD8+ T cells. In vivo functionality was validated in Rag2-/-c-/- mice.

Results: STEAP1/HLA-A*02:01 specific TCR CD4+ transduced T cells exhibit high peptide specificity. In vitro, CD4+ TCR transgenic T cells show similar tumor growth inhibition compared to CD8+ cells with the same transgene. Furthermore, in vivo data suggest a synergistic anti-ES effect of CD4+ and CD8+ cells transduced with the same STEAP1/HLA-A*02:01 specific TCR.

Conclusion: STEAP1/HLA-A*02:01 TCR transgenic CD4+ T cells exhibit direct cytotoxicity and execute synergistic helper functions. Combination of adoptively transferred TCR transgenic CD4+ and CD8+ T cells may result in better tumor control compared to transfer of respective TCR transgenic CD4+ or CD8+ T cells alone.

* U.T. and S.E.G.B. share senior authorship

Citation Format: Sebastian J. Schober, Melanie Thiede, David Schirmer, Dirk Wohlleber, Guenther Richter, Dirk H. Busch, Uwe Thiel, Stefan E. Burdach. Allorepertoire-derived HLA class I/peptide-specific T cell receptor transgenic CD4+ T cells mediate antitumor responses in Ewing sarcoma mimicking allo-rejection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-106.
Abstract LB-322: Casein kinase 2 is a major regulator of medulloblastoma growth
Authors: Nitta Ryan , Bolin Sara Matilda , Nwagbo Ginikachi , Purzner Teresa , Kahn Suzana , Cho Yoon-Jae , Li Gordon
Published: August 2018

Medulloblastoma (MB) is the most common malignant pediatric brain tumor, accounting for about 20% of all cases. While surgery, craniospinal irradiation, and chemotherapy have resulted in a cure rate of 70%, the surviving patients are afflicted with neurocognitive impairment, endocrine dysfunction, and a severe decrease in quality of life. Consequently, better and more effective treatments are needed to treat these young patients. Casein kinase 2 (CK2) is an intriguing therapeutic target for MB because it is dysregulated in all the MB molecular subgroups and patients with high CK2 expression have a significantly worse prognosis. To elucidate the role of CK2 in MB we transduced multiple MB cell lines with CK2 isoforms. We discovered that a CK2 isoform, CK2a, increased tumorigenesis in both the Sonic Hedgehog and Group 3 MB subgroups, while knocking down expression ameliorated MB growth. Through these transduced cell lines we also determined that CK2 can regulate MB tumorigenesis through b-catenin and potentially GLI1. Moreover, mice orthotopically injected with MB cells over-expressing CK2a or CK2b displayed a reduced survival compared to control. We extended our analysis to a CK2 inhibitor, CX-4945, which is currently undergoing phase I/II clinical trials for toxicity and safety. Treatment with CX-4945 reduced MB cell growth and also reduced expression of MGMT, a well-known regulator of temozolomide (TMZ) efficacy. Our findings were corroborated when we screened 4,000 FDA approved compounds to identify molecules that work synergistically with CX-4945. TMZ was one of the major compounds that were identified in the screen, suggesting that CX-4945 treatment can sensitize MB cells to TMZ by dysregulating MGMT. Combinatorial treatment with CX-4945 and TMZ had a synergistic effect on reducing MB tumor growth. Together, our findings suggest that CK2 is a novel therapeutic target for MB and that combining CX-4945 and TMZ can lead to a promising new MB therapy.

Citation Format: Ryan Nitta, Sara Matilda Bolin, Ginikachi Nwagbo, Teresa Purzner, Suzana Kahn, Yoon-Jae Cho, Gordon Li. Casein kinase 2 is a major regulator of medulloblastoma growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-322.
Abstract LB-358: Abnormal O-glycosylation promotes prostate cancer stemness and mediates metastatic niche
Authors: Tsai Chin-Hsien , Tzeng Sheue-Fen
Published: August 2018

Oncofetal Galβ1-3GalNAc O-glycan, T antigen, is increased in about 60% carcinomas of breast, colon, stomach, and prostate. Notably, coexpression of T antigen with CD44 or CD133, markers of cancer stem cells, has been identified in lung, breast, and liver cancers. Using spontaneous metastasis model of 22Rv1 cells, we derived high metastatic 22Rv1-M4 cells and found altered O-glycosylation in the 22Rv1-M4 cells and also 22Rv1-M4-derived host microenvironment compared to parental cells. Our study indicated that high expressions of T antigen synthase C1GALT1 are associated with metastatic PCa and poor survival, probably contributed by the interaction of galectin-4 and glycan. Galectin-4 engaged with MYC-dependent C1GALT1 mediated O-glycan and resulted in RTK phosphorylation; activation of RTKs enhanced not only androgen-independent growth but also metastatic colonization which mediated by ERK-AP1-mediated SOX9 expression. Downregulation of SOX9 significantly inhibited the tumorsphere formation and in vivo metastasis. Moreover, coexpression of SOX9 and MYC in immortalized prostate epithelial cells RWPE1 generates the heterogeneous population presenting both epithelial type and cancer-like cells in mouse renal capsule. On the other hand, analyses of lung tissues from mice bearing tumor of 22Rv1-M4 cells relative to that bearing tumor of 22Rv1 parental cells exhibit the upregulated O-glycosylation enzymes, which associated with increased plant Jacalin lectin staining, CD45+ cells infiltration, and endothelial permeability indicated by dextran leakage. Tail-vein injection of 22Rv1-M4 cells exhibits aggressive systemic metastasis in a mouse conditioned by subcutaneous 22Rv1-M4 tumor compared to that in a mouse conditioned by subcutaneous 22Rv1 tumor These data suggest high metastatic prostate cancer cells adapt the lung microenvironment for seeding and colonization of cancer cells.

Citation Format: Chin-Hsien Tsai, Sheue-Fen Tzeng. Abnormal O-glycosylation promotes prostate cancer stemness and mediates metastatic niche [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-358.