bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2477: Exosomal RNA mediates transformation of nontumorigenic human bronchial lung epithelial cells
Authors: Kitdumrongthum Sarunya , Humphrey Sean , Kubo Hana , Tian Feng , Allen Sarah , Atallah Nadia , Hasan Humna , Kasinski Andrea L.
Published: August 2018

Exosomes are nanovesicles with a diameter between 30-150 nm. Exosomes are produced and released by all cell types into body fluids and, thus, play a major role in cell-cell communication through the transfer of proteins, lipids, and nucleic acids into recipient cells. Uptake of bioactive cargo into recipient cells can impart physiologic and biologic changes in the recipient cell. Especially in cancer, exosome released from cancer cells can reprogram cells, driving various hallmarks of cancer, such as proliferation, migration, invasion, and angiogenesis. In this study we evaluated the effects of exosomes, isolated from non-small cell lung cancer (NSCLC) cells, on nontumorigenic human bronchial epithelial cells (HBECs). Firstly, we determined that cancer cells generate more exosomes than nontumorigenic cells and that cancer cell-derived exosomes are readily taken up by nontumorigenic cells. The nontumorigenic cells exposed to NSCLC-derived exosomes gained the ability to migration and invade. In parallel, we observed that NSCLC-derived exosomes promoted changes in epithelial-to-mesenchymal gene profiles, supporting the conclusion that HBECs were becoming transformed. Exosomes were also capable of permeablizing a monolayer of human endothelial cells, suggesting that NSCLC-derived exosomes may disrupt the vasculature enhancing metastatic capabilities. Importantly, the transformative effects of the exosomes were mediated mostly by exosomal RNA. Comparing the RNA profile from a panel of cancerous exosomes to RNAs contained inside of exosomes isolated from nontumorigenic, one long noncoding RNA (lncRNA) was highly elevated. Knockout of this lncRNA greatly diminished the capability of the cancerous exosomes to promote the observed hallmarks of cancer, suggesting that a single lncRNA is responsible for the majority of the tumorigenic capacity of the exosomes. In vivo mouse modeling and patient-based evidence are currently under way to support these cell-based findings.

Citation Format: Sarunya Kitdumrongthum, Sean Humphrey, Hana Kubo, Feng Tian, Sarah Allen, Nadia Atallah, Humna Hasan, Andrea L. Kasinski. Exosomal RNA mediates transformation of nontumorigenic human bronchial lung epithelial 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 2477.
Abstract 2485: CYP24A1-induced vitamin D insufficiency promotes breast cancer growth
Authors: Osanai Makoto , Ono Yusuke , Takasawa Akira , Takasawa Kumi , Murata Masaki , Sawada Norimasa
Published: August 2018

Vitamin D plays a critical role in the maintenance of tissue homeostasis by regulating the expression of genes affecting cell proliferation, differentiation, and apoptosis. The vitamin D 24-hydroxylase CYP24A1 functions in vitamin D target tissues to degrade the hormonal form of vitamin D. Existing knowledge regarding dysregulated CYP24A1 expression supports its candidacy as a putative oncogene. In our presentation, we demonstrate that the suppression of constitutive CYP24A1 expression by CYP24A1-specidic shRNA conferred target cells with increased susceptibility to apoptosis and consequently inhibited anchorage-independent growth in breast carcinoma cells. In addition, suppression of vitamin D metabolism following knockdown of CYP24A1 significantly reduced tumor growth in vivo. Since these data provide substantial evidence for a pro-survival and stimulatory oncogenic effect of CYP24A1 in breast carcinoma cells, we will discuss the potential feasibility of CYP24A1-inhibitory cancer therapies.

Citation Format: Makoto Osanai, Yusuke Ono, Akira Takasawa, Kumi Takasawa, Masaki Murata, Norimasa Sawada. CYP24A1-induced vitamin D insufficiency promotes breast cancer 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 2485.
Abstract 2507: Axl suppression inhibits cell migration, invasion and survival in breast and prostate cancer cell lines
Authors: Tanaka Mai , Dykes Samantha S. , Siemann Dietmar W.
Published: August 2018

Cancer is the second leading cause of death in the United States with approximately 90% of cancer-related deaths resulting from metastatic disease. In tumor cells, upregulation of certain signaling pathways promote metastatic phenotypes characterized by enhanced invasion, migration, survival, proliferation and induction of angiogenesis. One pathway of considerable interest involves the receptor tyrosine kinase Axl that is expressed in a variety of tumor types and is associated with poor prognosis and metastasis. Furthermore,

Axl's ligand, Growth arrest specific 6 (Gas6) protein, can activate a number of downstream signaling pathways that promote metastatic phenotypes. The purpose of the current study was to characterize Axl and Gas6 in a number of human tumor cell lines and to determine the effect of Axl suppression on the metastatic phenotypes, specifically cell migration, invasion and survival. A panel of human tumor cell lines, including prostate, breast, colorectal, renal, and osteosarcoma, were characterized for Axl expression by Western blot and qPCR. Gas6 expression was assessed by qPCR and Gas6 secretion was determined in conditioned media by ELISA. Axl was genetically inactivated by shRNA

in prostate (DU145) and breast (MDA-MB-231) cancer cell lines. The efficiency of knockdown was determined by Western blot. The effect of Axl knockdown on the migratory and invasive potentials of these cell lines was evaluated by transwell migration and invasion assays. A clonogenic cell survival assay was used to assess the impact of Axl knockdown on tumor cell viability. Axl-expressing tumor cells expressed and secreted its ligand Gas6, suggesting that Axl is co-expressed with Gas6, and may be mediated by autocrine regulation. Genetic inactivation of Axl (shRNA) inhibited cell migration, invasion and reduced clonogenic cell survival in both the MD-MB-231 breast and DU145 prostate cancer cell lines. These findings suggest that Axl may be a novel therapeutic target to inhibit the dissemination of tumor cells. Ongoing experiments are evaluating the impact of the Axl-targeting agent R428 on Axl signaling and metastatic phenotype.

Citation Format: Mai Tanaka, Samantha S. Dykes, Dietmar W. Siemann. Axl suppression inhibits cell migration, invasion and survival in breast and prostate cancer cell lines [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 2507.
Abstract 2550: Generation of CAR-iPS-T cells expressing CD8β
Authors: Ueda Tatsuki , Iriguchi Shoichi , Kawai Yohei , Minagawa Atsutaka , Miyoshi Hiroyuki , Terakura Seitaro , Uemura Yasushi , Woltjen Knut , Kodama Yuzo , Seno Hiroshi , Hitoshi Yasumichi , Nakatsura Tetsuya , Tamada Koji , Kaneko Shin
Published: August 2018

Chimeric antigen receptor (CAR) is an artificial protein that provides HLA-independent antigen specificity to T cells. CAR-T therapy has shown remarkable clinical responses especially in hematologic malignancies. But this therapy needs cell preparation for each patient. That limits its applicability. We have reported regeneration of T cells from iPSCs (Cell Stem Cell 2013). This technology provides unlimited number of T cells, so CAR-T therapy using iPSCs can broadens its applicability. Regenerated T cells previously described in some reports including ours have some different characters from peripheral T cells. In particular, they express only CD8α, and do not express CD8β. We successfully generate CAR-iPS-T cells expressing CD8β with some modification of differentiation protocols. We assayed the function of CAR-iPS-T cells in view of the difference between CD8β positive and negative iPS-T cells. We found CD8β positive CAR-iPS-T cells showed enhanced function to suppress tumor progression compared with CD8β negative CAR-iPS-T cells in subcutaneous xenograft model. In vivo kinetics study revealed that CD8β positive CAR-iPS-T cells have superior function to traffic to target expressing tumor site and enhanced sustainability in vivo compared with CD8β negative CAR-iPS-T cells. These findings indicate that CD8β positive CAR-iPS-T cells may be a potent cell source for iPSC-based cancer immunotherapy.

Citation Format: Tatsuki Ueda, Shoichi Iriguchi, Yohei Kawai, Atsutaka Minagawa, Hiroyuki Miyoshi, Seitaro Terakura, Yasushi Uemura, Knut Woltjen, Yuzo Kodama, Hiroshi Seno, Yasumichi Hitoshi, Tetsuya Nakatsura, Koji Tamada, Shin Kaneko. Generation of CAR-iPS-T cells expressing CD8β [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 2550.
Abstract 2571: An integral genomic/expression analysis reveals a cooperative role of APC and TP53 mutations in identifying cetuximab-sensitive colorectal cancer
Authors: Yang Mingli , Schell Michael J. , Loboda Andrey , Nebozhyn Michael V. , Li Jiannong , Teer Jamie K. , Pledger W. Jack , Yeatman Timothy J.
Published: August 2018

The epidermal growth factor receptor (EGFR) is a major therapeutic target in metastatic colorectal cancer (CRC). Mutations in KRAS/NRAS have been identified as the resistance mechanisms to anti-EGFR antibody therapy (cetuximab/pantiumab). However, genomic understanding of the sensitivity to the EGFR-targeted therapy is lacking. A pre-specified, 203-gene cetuximab sensitivity (CTX-S) expression signature score was first validated on two previously published datasets: (1) 77 CTX-treated CRC tumors (progression free survival (PFS)>7 days), and (2) 147 in vitro CTX-treated CRC cell lines. The CTX-S signature was found to be consistently correlated with a newly developed 24-gene APC (truncating) mutations-specific Wnt/β-catenin score on four independent CRC datasets that also include Moffitt (n=468) and TCGA (n=624) CRC datasets. This promoted us to carry out a variety of analyses that revealed a cooperative role of mutant APC + mutant TP53 in identifying cetuximab sensitive subpopulations, which was further evidenced by additional validation analysis on two CRC PDX datasets (n=52 and n=98). While debating or inconclusive, other potential predictive markers of EGFRi therapies have been reported, including BRAF(V600E), PIK3CA mutations, loss of PTEN, and overexpression of HER2 as negative indicators, as well as increased EGFR copy number, and overexpression of EGFR ligands epiregulin and amphiregulin as positive indicators. Here, for the first time, we report that the mutant genes may cooperatively act as positive indicators of EGFRi response. Our study suggests that addition of the routine sequencing of APC and TP53 to extended RAS testing may refine the patient selection strategy to improve cetuximab/pantiumab response and potentially expand the therapeutic opportunity to previously-excluded mutant KRAS/NRAS patients who have “APC + TP53” mutations.

Citation Format: Mingli Yang, Michael J. Schell, Andrey Loboda, Michael V. Nebozhyn, Jiannong Li, Jamie K. Teer, W. Jack Pledger, Timothy J. Yeatman. An integral genomic/expression analysis reveals a cooperative role of APC and TP53 mutations in identifying cetuximab-sensitive colorectal 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 2571.
Abstract 258: Targeting Nanog in 3D explant models for the evaluation of cancer prevention agents
Authors: Khan Sam , Karmokar Ankur , Sidat Zahirah , Foreman Nalini , Moore David , Higgins Jennifer , Parrott Emma , Theofanous Despoina , Hobbs Dominic , Howells Lynne , Thomas Anne , Brown Karen
Published: August 2018

Background: The transcription factor Nanog is crucial for the self-renewal of cancer stem-like cells (CSCs). Nanog expression in colorectal cancer (CRC) tissue correlates with lymph node metastasis and poor prognosis. Since Nanog is not expressed in most tissues, including normal adult stem-cells, it represents a therapeutic target specific to cancer cells. Curcumin inhibits proliferation and expansion of CSCs derived from CRC and adenomas. In NOD/SCID mice bearing xenografts from patient-derived CRC CSCs, curcumin significantly inhibited tumour growth and improved survival. In addition, curcumin binds directly to Nanog recombinant protein (quantified using microscale thermophoresis). We have developed 3D in-vitro primary human explant models to further characterise the effects of curcumin on Nanog. In this work the hypothesis is tested that Nanog may be an early marker of response for CRC prevention agents.

Methods: Patient-derived CRC and adenoma tissue was cubed (2x2x2mm) and treated for 24 hours with curcumin. Following treatment, explant tissues were processed for analysis by immunohistochemistry (IHC) (n=6) and flow cytometry (n=17). The effect of curcumin on CSCs (defined by expression of aldehyde dehydrogenase (ALDH) or Nanog) and differentiation (via Mucin 2 expression) was analysed using IHC. Additionally, cells expressing Nanog (Nanog+) or Nanog plus proliferation marker Ki67 (Nanog+Ki67+) were assessed using flow cytometry.

Results: A range of adenoma (n=5) and Dukes stage A-C CRC (n=18) samples were studied. Following exposure to curcumin, a 30% reduction was observed in Nanog+ and Nanog+Ki67+ cells. Nanog+ cell number was decreased in a curcumin concentration-dependent fashion in 6 samples and concentration-independently in a further 8. No response was observed in 3 samples. A reduction in Nanog and ALDH with concurrent increase in differentiation was observed via IHC in one sample.

Conclusion: Our data suggest Nanog is targeted by curcumin in adenoma and CRC tissues. Nanog may serve as a biomarker in clinical trials to identify individuals most amenable to treatment with curcumin alone or in combination treatment. Crucially, this will help select those who are likely to benefit from curcumin as a cancer prevention agent. Ultimately, this concept may be applicable to the evaluation of novel CRC prevention agents.

Citation Format: Sam Khan, Ankur Karmokar, Zahirah Sidat, Nalini Foreman, David Moore, Jennifer Higgins, Emma Parrott, Despoina Theofanous, Dominic Hobbs, Lynne Howells, Anne Thomas, Karen Brown. Targeting Nanog in 3D explant models for the evaluation of cancer prevention agents [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 258.
Abstract 2581: Plasma HPV cell free DNA as an earlier predictor of treatment response in advanced oropharyngeal cancer
Authors: Hanna Glenn J. , Supplee Julianna G. , Kuang Yanan , Geary Kate , Janne Pasi A. , Haddad Robert I. , Paweletz Cloud P.
Published: August 2018

Purpose: Human papillomavirus (HPV) is associated with the majority of oropharyngeal squamous cell carcinomas (OPSCC), with a rising incidence of OPSCC predominantly among middle-aged men. Tumor-derived HPV cell-free (cf)DNA can be detected and quantified in circulation with high sensitivity and specificity. Although cfDNA has limited clinical application in monitoring locoregional spread of these tumors, up to 10% of HPV+ OPSCC patients present or recur with distant, metastatic disease. The potential of HPV DNA monitoring in this setting remains largely unexplored.

Methods: We present a proof-of-concept prospective observational cohort of recurrent, metastatic (R/M) HPV+ OPSCC patients treated with standard systemic therapies. We utilized droplet digital (dd)PCR to identify and quantify HPV cfDNA (strains 16, 18, 31, 33 and 45) at multiple time points throughout treatment. We then compared HPV cfDNA concentration at various timepoints with clinical parameters such as disease burden and treatment response.

Results: Clinicopathologic data from 12 R/M patients revealed a predominantly male cohort (11/12, 92%) with a median age of 55 at diagnosis. Eight (67%) were on immunotherapy treatments and the other four on standard chemotherapy during the study period (2.5 months). Plasma HPV cfDNA was detected in 6/12 (50%) samples (range 0-4460 copies/mL) in at least one timepoint during the study. All patients with undetectable HPV cfDNA had evidence of stable, low burden disease or no measurable lesions (near-complete response) on their current therapy. HPV cfDNA levels strongly correlated with both disease burden (p < 0.01) and distant disease sites (p < 0.01). In three cases, HPV DNA levels declined prior to contrast enhanced imaging findings which later confirmed treatment response (up to 14 days prior to planned imaging).

Conclusion: Our results suggest that high sensitivity plasma HPV cfDNA levels can be an early indicator of treatment response. HPV cfDNA monitoring could significantly impact clinical decision-making and improve patient outcomes by informing treatment response or failure. Further studies are underway to validate these findings and determine how early cfDNA can detect metastatic disease.

Citation Format: Glenn J. Hanna, Julianna G. Supplee, Yanan Kuang, Kate Geary, Pasi A. Janne, Robert I. Haddad, Cloud P. Paweletz. Plasma HPV cell free DNA as an earlier predictor of treatment response in advanced oropharyngeal 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 2581.
Abstract 2648: Prognostic significance of thyroid hormone receptor-alpha-2 (THRα2) expression in triple-negative breast cancer: A TCGA study
Authors: Jerzak Katarzyna J. , Dvorkin-Gheva Anna , Cockburn Jessica G. , Bane Anita , Hassell John A.
Published: August 2018

Background: Thyroid hormones promote breast cancer cell proliferation and expression of their cognate nuclear receptors has shown prognostic potential in small cohort studies. Among two isoforms of thyroid hormone receptor alpha (THRα), the alpha1 splice variant (THRα1) promotes thyroid hormone mediated cell proliferation whereas the alpha2 variant (THRα2) opposes it. Hence, THRα2 expression may be a favorable prognostic biomarker in breast cancer.

Methods: A publicly available database of breast tumors archived by The Cancer Genome Atlas (TCGA) was employed for this study. We analyzed RNA expression of THRα1 and THRα2 in 106 triple negative breast cancers (TNBCs) and correlated it with tumor stage (I vs II vs III) and nodal involvement (positive vs negative). Tumor grade was not uniformly reported. Univariate Cox proportional hazards regression models were fitted to determine the prognostic impact of THRα1 and THRα2 expression on overall survival (OS) and multivariate models were adjusted for age, tumor stage and radiation treatment.

Results: The median age of women was 54 (range 29-90) and 12.3% died. The majority (62.3%) of patients presented with stage II disease; 16.0% were stage III and 17.9% were stage I at diagnosis. There was no significant correlation between THRα1 or THRα2 expression and tumor stage or nodal involvement. Expression of THRα2 was associated with improved OS in both uni- and multi-variate models (Table).

Conclusions: In this study, THRα2 expression was independently prognostic for improved OS in TNBC. We previously demonstrated similar results in 158 TNBCs via immunohistochemistry but differentiation between RNA (as opposed to protein) splice variants is more precise. These results support investigation of THRα2 up-regulation or THRα1 inhibition as therapeutic strategies.

Table. Prognostic associations of THRα2 expression in TNBCVariableUnivariate HR (95%CI)p valueMultivariate HR (95%CI)p valueLog (THRα2)0.46 (0.26-0.81)<0.010.28 (0.09-0.84)0.02Log (THRα1)0.54 (0.31-0.94)0.031.38 (0.53-3.62)0.51Age (years)0.98 (0.94-1.02)0.370.92 (0.84-1.01)0.10Stage (I vs II vs III vs IV)6.14 (2.19-17.22)<0.0126.03 (4.05-167.14)<0.01Radiation therapy (yes vs no)0.23 (0.04-1.22)0.080.10 (0.02-0.73)0.02

Citation Format: Katarzyna J. Jerzak, Anna Dvorkin-Gheva, Jessica G. Cockburn, Anita Bane, John A. Hassell. Prognostic significance of thyroid hormone receptor-alpha-2 (THRα2) expression in triple-negative breast cancer: A TCGA study [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 2648.
Abstract 267: Nonsteroidal anti-inflammatory drugs induce ER stress- and BID-dependent immunogenic cell death to suppress colorectal tumorigenesis
Authors: Fletcher Rochelle Elayne , Leibowitz Brian , Wang Yijun , Concha-Benavente Fernando , Ferris Robert , Schoen Robert , Yu Jian , Zhang Lin
Published: August 2018

Prevention or early detection represents a key approach for reducing the mortality and morbidity of CRC. Use of non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with decreased risk of CRC in numerous epidemiological studies, clinical trials, and animal model studies. However, the mechanism by which NSAIDs suppress colorectal tumorigenesis has remained unclear. We previously demonstrated that the chemopreventive effect of NSAIDs is mediated by a synthetic lethal interaction between death receptor signaling and loss of the gatekeeper APC tumor suppressor, which is dependent on the BH3-only Bcl-2 family member BID. In this study, we found a critical role of endoplasmic reticulum (ER) stress upstream of death receptor signaling and BID activation. Elevated levels of ER stress and cell death markers were detected in advanced adenomas from patients taking NSAIDs including aspirin. Inhibiting ER stress using a pharmacological approach abolished the apoptotic effect of NSAIDs in CRC cells and normal colonic epithelial cells with APC loss and also suppressed the chemopreventive activity of the NSAID sulindac in APCMin/+ mice. Importantly, our results unveiled a critical role of ER stress and BID-dependent cell death in triggering immune-mediated elimination of nascent cells that lose APC. Markers of immunogenic cell death (ICD), including plasma membrane translocation of calreticulin and phagocytosis by dendritic cells, were suppressed in cells with BID knockout or ER stress inhibition. BID knockout or ER stress inhibition also reduced tumor infiltrating lymphocytes (TILs) in sulindac-treated APCMin/+ mice. Collectively, our results suggest that NSAIDs suppress colorectal tumorigenesis by enhancing immunosurveillance through ER stress and BID-dependent ICD. These results provide novel insight into the chemopreventive mechanism of NSAIDs, which may help design more effective chemopreventive strategies and agents.

Citation Format: Rochelle Elayne Fletcher, Brian Leibowitz, Yijun Wang, Fernando Concha-Benavente, Robert Ferris, Robert Schoen, Jian Yu, Lin Zhang. Nonsteroidal anti-inflammatory drugs induce ER stress- and BID-dependent immunogenic cell death to suppress colorectal tumorigenesis [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 267.
Abstract 2671: 17beta-hydroxywithanolides inhibit the proliferation of castration-resistant prostate cancer cells by reducing levels of cFLIP
Authors: Brooks Alan D. , Wright Nicola E. , Xu Ya-ming , Wijeratne Kithsiri , Tewary Poonam , Cross Neil , Gunatilaka A. A. Leslie , Sayers Thomas J.
Published: August 2018

Using a high throughput gene expression profiling assay directly targeting genes of the androgen receptor pathway, we previously identified the 17beta-hydroxywithanolide (17-BHW), physachenolide C (PCC), as a potent inhibitor of prostate cancer cell growth. Using a panel of prostate cancer cell lines, PCC at low concentrations (IC50 20-50 nM) reduced prostate cancer cell numbers under both standard and 3D in vitro growth conditions. This reduction in cell number was due to growth inhibition and not apoptosis, with PCC causing reductions in the levels of cyclin D, an increase in p21 and arrest of cells in the G1 phase of the cell cycle. Subsequently over 150 natural and semi-synthetic withanolides were evaluated for their ability to inhibit prostate cancer cell growth. All highly active withanolides were 17-BHWs, and some were up to 4-fold more active than PCC. Preliminary structure-activity relationship (SAR) studies suggested that the enone moiety in ring A was essential for activity. In addition, acetoxylation at C-18, an alpha orientation of the side-chain lactone group and the double bond at C-24(25) of the lactone ring played important roles in determining the activity of 17-BHWs as inhibitors of prostate cancer cell growth. Interestingly highly active 17-BHWs rapidly reduced levels of both antiapoptotic cFLIPL and cFLIPS proteins in 22Rv1 prostate cancer cells. However, this reduction did not sensitize 22Rv1 cells to apoptosis. Nonetheless specific reduction of cFLIPL in the castration-resistant 22Rv1 cells using siRNA significantly inhibited their proliferation. This suggests that cFLIPL plays a critical role in the proliferation of some castration-resistant prostate cancer cells. Since the 17-BHW scaffold is amenable to optimization by a medicinal chemistry approach, this could lead to the identification of highly active natural product-based inhibitors of castration-resistant prostate cancer cell proliferation. The cellular molecular target(s) of active 17-BHWs that promote cFLIP reduction are currently under further investigation.

Funded by FNLCR Contract HHSN261200800001E and the University of Arizona.

Citation Format: Alan D. Brooks, Nicola E. Wright, Ya-ming Xu, Kithsiri Wijeratne, Poonam Tewary, Neil Cross, A. A. Leslie Gunatilaka, Thomas J. Sayers. 17beta-hydroxywithanolides inhibit the proliferation of castration-resistant prostate cancer cells by reducing levels of cFLIP [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 2671.
Abstract 2674: Novel tubulin polymerization inhibitors repress tumor xenografts in nude mice and leukemia in zebrafish
Authors: Xie Yanqi , Kril Liliia , Zhang Wen , Frasinyuk Mykhaylo , Bondarenko Svitlana , Hausman Elizabeth , Martin Zachary , Wyrebek Przemyslaw , Yu Tianxin , Zhan Changguo , Sviripa Vitaliy , Blackburn Jessica , Watt David , Liu Chunming
Published: August 2018

In an effort to screen natural compounds and their derivatives as novel agents for cancer treatment, we developed two semisynthetic nature compounds, A14 and A52, which have potencies in an in vitro cell proliferation studies against LS174T and PC-3 cells in the mid-nanomolar range. A14 inhibited more than 90% of in vitro cancer cell proliferation around 300 nM and also inhibited in vivo PC-3 prostate cancer xenografts in nude mice. Cell morphology studies and comparisons with known antineoplastic agents suggested that A14 disrupted microtubule organization. In vitro tubulin polymerization assay suggested that A14 inhibited this process. Based on molecular docking, A14 fits very well in the colchicine-binding site at the interface between the alpha-tubulin and beta-tubulin. Further analyses suggest that A14 sensitivity may correlate with CDK/cyclin activity. A14 inhibited PC-3 prostate cancer xenografts in nude mice. In addition to solid tumors, A14 and its analog A52 strongly inhibited a panel of human leukemia cancer cell lines. Furthermore, these compounds inhibited Myc-induced T cell acute lymphoblastic leukemia (T-ALL) in a zebrafish model. Although many tubulin inhibitors were available, there is no compound that targeting the colchicine-binding site has been approved by FDA for cancer treatment. This new family of tubulin polymerization inhibitors could be further developed for the treatment of both solid and liquid tumors.

Citation Format: Yanqi Xie, Liliia Kril, Wen Zhang, Mykhaylo Frasinyuk, Svitlana Bondarenko, Elizabeth Hausman, Zachary Martin, Przemyslaw Wyrebek, Tianxin Yu, Changguo Zhan, Vitaliy Sviripa, Jessica Blackburn, David Watt, Chunming Liu. Novel tubulin polymerization inhibitors repress tumor xenografts in nude mice and leukemia in zebrafish [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 2674.
Abstract 2688: ZB716 is orally efficacious in blocking tumor growth in mouse xenograft models
Authors: Guo Shanchun , Zhang Changde , Liu Jiawang , Zheng Shilong , Yang Lin , Wang Guangdi
Published: August 2018

Advances in oral SERDs development so far have been confined to nonsteroidal molecules such as those containing a cinnamic acid moiety, which are in early-stage clinical evaluation. ZB716 was previously reported as an orally bioavailable SERD structurally analogous to fulvestrant. In this study, we examined the binding details of ZB716 to the estrogen receptor alpha (ERα) by computer modeling to reveal its interactions with the ligand binding domain as a steroidal molecule. The ability of ZB716 to inhibit cell growth and downregulate ER expression in endocrine resistant, ERα mutant breast cancer cells was demonstrated. Moreover, in the MCF-7 xenograft and two patient derived xenograft models, orally administered ZB716 showed superior efficacy in blocking tumor growth when compared to fulvestrant. Importantly, such enhanced efficacy of ZB716 was shown to be attributable to its markedly higher bioavailability, as evidenced in the final plasma and tumor tissue concentrations of ZB716 in mice where drug concentrations were found significantly higher than in the fulvestrant treatment group.

Citation Format: Shanchun Guo, Changde Zhang, Jiawang Liu, Shilong Zheng, Lin Yang, Guangdi Wang. ZB716 is orally efficacious in blocking tumor growth in mouse xenograft models [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 2688.
Abstract 2697: Alterations in the HSP70 interactome are induced by overexpression of MUC1 in pancreatic cancer
Authors: Nitika . , Wolfgeher Donald J. , Mukherjee Pinku , Truman Andrew W.
Published: August 2018

Heat Shock Protein 70 (HSP70) is an evolutionarily well-conserved molecular chaperone involved in several cellular processes such as folding of proteins, modulating protein-protein interactions and transport of proteins across membranes. HSP70 works synergistically with a series of chaperones, co-chaperones, adaptors, and folding enzymes known as the HSP70 “interactome”. Previous work has demonstrated that HSP70 interactome changes can be promoted by overexpression of oncoproteins. An important “client” of HSP70 is the oncoprotein MUC1. MUC1 is overexpressed and promotes drug resistance in pancreatic cancer. We applied quantitative affinity-purification mass spectrometry (AP-MS) to characterize the HSP70 interactome differences between PC3/NEO and PC3/MUC1 cell lines. 439 HSP70-interacting proteins were identified and quantified via LC-MS/MS. Interestingly while 53% of HSP70 interactions remained constant upon MUC1 overexpression, 29% significantly increased and 18% decreased. Many of the altered proteins were key co-chaperones that regulate and maintain HSP70 activity. High levels of MUC1 promoted HSP70 association with 15 co-chaperones (HSPA5, DNAJB1, STIP1, TXNDC5, HSPB1, CCT2, TCP1, P4HB, CCT6A, CCT8, PDIA3 and HSP90B). Conversely, MUC1 overexpression triggered the loss of HSP70 interaction with only 2 co-chaperones (PPIB and DNAJA2). We are currently validating these altered interactions using an array of biochemical techniques. Our hope is that by understanding these HSP70 interactome changes, we may be able to uncover novel ways to inhibit MUC1 function in pancreatic cancer.

Citation Format: . Nitika, Donald J. Wolfgeher, Pinku Mukherjee, Andrew W. Truman. Alterations in the HSP70 interactome are induced by overexpression of MUC1 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 2697.
Abstract 2713: Preclinical development of first-in-class antibodies targeting Siglec-9 immune checkpoint for cancer immunotherapy
Authors: Bénac Olivier , Gaudin Marion , Ors Mélody , Roy Aude Le , Blanc Hélène Rispaud , Soulas Caroline , Chanteux Stéphanie , Rossi Benjamin , Gauthier Laurent , Paturel Carine , Morel Yannis , Perrot Ivan , Cornen Stéphanie
Published: August 2018

Siglec-9 is a MHC class I-independent inhibitory receptor expressed on NK and myeloid cells (including dendritic cells, monocytes and neutrophils). Its ligands are sialic acid-containing carbohydrates which are over-expressed on various tumor types compared to normal tissues (1). Sialylation of tumor cells is involved in tumor cell malignancy and is reported for decades as a mechanism of escape from immune surveillance (2). The loss of beta-2-microglobulin, an essential component of MHC class I antigen presentation, was recently described as a common mechanism of resistance to checkpoint blockade in clinical trials and revealed the need for MHC class I-independent therapies (3-4). Thus, Siglec-9-sialic acid interaction disruption may promote anti-tumor immunity independently of MHC class I expression by tumors. Here, we describe the discovery and characterization of first-in class anti-human Siglec-9 antibodies as new checkpoint blockade therapy in a wide range of cancers. Antibodies were discovered that efficiently block the interaction between Siglec-9 and its ligands. Epitope mapping revealed that antibodies bind to distinct epitopes on Siglec-9 near the sialic acid binding site. In vitro assays showed that they potently reverse inhibitory functions of Siglec-9 on NK cells leading to subsequent sialic acid-expressing tumor cell killing. Interestingly, Siglec-9 is enhanced on both CD4+ and CD8+ T cells from RCC, melanoma and NSCLC PBMC patients suggesting a putative additional role on adaptive immunity. Siglec-9 was also co-expressed with other inhibitory receptors on NK cells and combination with other immune checkpoint blockers in in vitro assays is ongoing. The antibodies displaying the most interesting features were successfully humanized. (1) Pathol Oncol Res. 2016 Jul;22(3):443-7 (2) Nature. 1968 Jun 29;218(5148):1254-5 (3) Nat Commun. 2017 Oct 26;8(1):1136 (4) N Engl J Med. 2016 Sep 1;375(9):819-29

Citation Format: Olivier Bénac, Marion Gaudin, Mélody Ors, Aude Le Roy, Hélène Rispaud Blanc, Caroline Soulas, Stéphanie Chanteux, Benjamin Rossi, Laurent Gauthier, Carine Paturel, Yannis Morel, Ivan Perrot, Stéphanie Cornen. Preclinical development of first-in-class antibodies targeting Siglec-9 immune checkpoint for cancer immunotherapy [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 2713.
Abstract 273: Upregulation of 15-hydroxyprostaglandin dehydrogenase expression by 15-Deoxy-Δ12,14-prostaglandin J2 through inactivation of DNA methyltransferase 1
Authors: Jang Hye-Ok , Kim Hye-Rim Kim , Lee Ha-Na , Kim Do-Hee , Surh Young-Joon , Na Hye-Kyung
Published: August 2018

15-Hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the oxidation of prostaglandin E2 (PGE2) to a biologically inactive keto metabolite 15-keto-PGE2. However, the molecular mechanisms underlying regulation of 15-PGDH expression remain largely elusive. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), an endogenous ligand of peroxisome proliferator-activated receptor γ, has been reported to have anti-inflammatory and anti-carcinogenic activities. In the present study, we have found that 15-PGJ2 upregulates expression and catalytic activity of 15-PGDH in human breast cancer (MDA-MB-231) cells. 15d-PGJ2 treatment decreased the CpG methylation in the 15-PGDH promoter in MDA-MB-231 cells as determined by the bisulfite genome sequencing and methyl-specific PCR. 15d-PGJ2 inhibited catalytic activity of methyltransferase 1 (DNMT1) but did not influence DNMT expression. 15d-PGJ2 increased the expression of c-Fos which is a functional subunit of AP-1. Chromatin-immunoprecipitation analysis revealed that 15d-PGJ2 significantly attenuated DNMT1 binding to the site for AP-1 transcription factor present in the 15-PGDH promoter regions, while increasing c-Fos binding. Biotin-tagged 15d-PGJ2 directly bound to DNMT1, and reduced its catalytic activity. A non-electrophilic analogue 9,10-dihydro-15d-PGJ2 failed to suppress the methylation of CpG islands present in 15-PGDH promoter and did not affect both DNMT1 activity and 15-PGDH expression. This findings suggests that the α,β-unsaturated carbonyl group of 15d-PGJ2 is essential for its inactivation of DNMT1 and expression of 15-PGDH. In conclusion, 15d-PGJ2 directly interacts with DNMT1 and consequently suppresses DNMT1-mediated hypermethylation of 15-PGDH promoter, leading to upregulation of 15-PGDH expression.

Citation Format: Hye-Ok Jang, Hye-Rim Kim Kim, Ha-Na Lee, Do-Hee Kim, Young-Joon Surh, Hye-Kyung Na. Upregulation of 15-hydroxyprostaglandin dehydrogenase expression by 15-Deoxy-Δ12,14-prostaglandin J2 through inactivation of DNA methyltransferase 1 [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 273.
Abstract 2733: Developing novel anti-OX40 antibodies on Biocytogen's in vivo drug screening platform
Authors: Guo Chaoshe , Guo Yanan , Shen Yuelei , Yang Benny
Published: August 2018

OX40, also known as CD134 or TNFRSF4, is a member of the TNFR superfamily of receptors. OX40 is a co-stimulatory receptor, and it interacts with its ligand to providepositive signal for T cell activation. OX40 is not expressed on resting naïve T cells, however its expression goes up after 24 to 72 hours following activation. Disruption of OX40 pathway led to defective T cell responses and overexpression of OX40 caused massive immune activation. Due to its importance in keeping immune homeostasis, strategies modulating the OX40 pathway hold great promise in fighting against cancer and autoimmune diseases. We have interests in developing novel OX40 antibodies for boosting cancer patients' own immunityinlight of other successful immune checkpoint modulators. We developed a cohort of OX40 specific antibodies using the classic hybridoma technology. In order to screen their efficacy to stimulate anti-tumor activity in live animals, we managed to rank these antibodies using Biocytogen'shumanized mouse platform of immune checkpoints. Specifically, we utilized humanized OX40 mice (h-OX40) and implanted syngeneic tumors subcutaneously, followed by treating mice with purified testing antibodies. Via this approach, we are able to discern several lead antibodies that effectively inhibited tumor growth without prior knowledge of their in vitro activities. Furthermore, we identified that one clone works in concert with Keytruda in the dual humanized model of h-OX40 and h-PD1. We are currently investigating the mechanisms of action underlying these potentially useful antibodies.

Citation Format: Chaoshe Guo, Yanan Guo, Yuelei Shen, Benny Yang. Developing novel anti-OX40 antibodies on Biocytogen's in vivo drug screening platform [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 2733.
Abstract 2745: EpCAM targeted immunotoxin prolongs survival of metastatic colorectal cancer patients by a previously unknown immunostimulatory mechanism
Authors: Fodstad Øystein , Dueland Svein , Flatmark Kjersti , Inderberg Else Marit , Kvalheim Gunnar , Andersson Yvonne
Published: August 2018

A first-in-man study of the anti-EpCAM immunotoxin MOC31PE with and without parallel immunosuppression with Cyclosporin A (CsA) was performed in metastatic colorectal cancer (CRC) patients. The safety and maximum tolerable doses in patients with EpCAM-positive tumors were determined, and only mild and reversible dose-limiting liver toxicity was seen, with no subjective side effects to the patients. Although no complete or partial responses were observed on CT scans at eight weeks, upon evaluation of the overall survival (OS) of the patients we surprisingly found that CRC patients treated with immunotoxin alone (n=15) had a median OS of 16.3 months (95% CI=5.6-27.0) compared to 6.0 months (CI=5.8-6.2) (p<0.001) for the combination group (n=18) (hazard ratio (HR): 0.248, 95% credible interval (CrI): 0.109-0.564). The 6.0 months OS for the patients treated with CsA in addition to the immunotoxin is comparable to OS of patients with progressive disease on last line of standard chemotherapy. The Th1 cytokine profile in sera from patients treated with MOC31PE alone indicated that the immuntoxin induces an immunogenic cell death resulting in T-cell activation, and that this effect disappeared in the patients who had received simultaneous treatment with CsA. Further, we demonstrate in in vitro experiments that the immunogenic cell death factors ATP and HMGB1 were secreted from CRC cell lines treated with MOC31PE alone. Finally, conditioned media from MOC31PE treated CRC cells induced maturation of dendritic cells and promoted activation of killer (CD8+) and helper (CD4+) T cells, showing that MOC31PE treatment induces release of immune stimulating factors. The present results demonstrate the novel and exciting finding that MOC31PE induces an immunogenic effect resulting in prolonged overall survival of patients with metastatic CRC, an effect obliterated by the parallel immunosuppression of CsA.

Citation Format: Øystein Fodstad, Svein Dueland, Kjersti Flatmark, Else Marit Inderberg, Gunnar Kvalheim, Yvonne Andersson. EpCAM targeted immunotoxin prolongs survival of metastatic colorectal cancer patients by a previously unknown immunostimulatory mechanism [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 2745.
Abstract 2752: EGFR tyrosine kinase inhibitor limits tumor relapse through enhancing anti-tumor T cell responses
Authors: Liu Zhida , Han Chuanhui , Shen Aijun , Dong Chunbo , Qiao Jian , Fu Yang-Xin
Published: August 2018

EGFR tyrosine kinase inhibitors (TKIs) have been clinically considered as the first line therapy for EGFR-driven tumor patients. Although the initial outcome of patients has significantly improved, almost all patients eventually relapse. Fully understanding the mechanisms of the anti-tumor effect of EGFR TKIs will help promote the clinical development of more efficient therapeutic strategies. The traditional view of the main mechanism is that the inhibitors can directly inhibit EGFR downstream signaling pathways to induce tumor cell death. Whether and how EGFR TKIs affect the host immune system is largely unknown. In current study, we have established syngeneic murine tumor models that are sensitive to EGFR TKIs treatment. To our surprise, we revealed that EGFR TKI treatment could control tumor growth and limit tumor relapse in T cells dependent manner. Mechanistically, EGFR TKI triggers type I IFN and its stimulation gene CXCL10 production through the Myd88 signaling pathway to enhance tumor specific T cells infiltration and activation. However, EGFR TKI cannot efficiently limit tumor relapse in advanced tumor models because of PD-L1 upregulation in the tumor microenvironment after treatment. We have observed that anti-PDL1 blockade can synergize with EGFR TKI to control advanced tumors. Our study will challenge the current regimen of EGFR TKI in clinic and provide new efficient therapeutic strategies for EGFR dependent cancer patients.

Citation Format: Zhida Liu, Chuanhui Han, Aijun Shen, Chunbo Dong, Jian Qiao, Yang-Xin Fu. EGFR tyrosine kinase inhibitor limits tumor relapse through enhancing anti-tumor T cell responses [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 2752.
Abstract 2799: New-generation glucose transporter inhibitors targeting non-small cell lung cancer and triple-negative breast cancer
Authors: Shriwas Pratik , Qian Yanrong , Wang Xuan , Roberts Dennis , Bergmeier Stephen , Chen Xiaozhuo
Published: August 2018

Cancer is a top killer second only to cardiovascular diseases. Cellular metabolic reprogramming and altered energetics are key features of cancer. Opportunistic uptake of extracellular nutrients has recently been named as an emerging hallmark of cancer metabolism. Glucose is a key nutrient taken in by cancer cells to meet their high energy and biosynthesis needs. Drastic upregulation of glucose uptake and glycolytic activity, a phenomenon called the Warburg effect, is prevalent in most cancers, including non-small cell lung cancer (NSCLC) and triple-negative breast cancer (TNBC). Cancer cells overexpress specific glucose transporters (GLUTs), particularly GLUT1, on their membranes to transport glucose via facilitated diffusion. Considering the addiction of cancer cells for glucose and their sensitivity and vulnerability to changes in glucose supply, GLUTs, especially GLUT1, have been recognized as an attractive anticancer target. We previously reported the identification of first-generation lead GLUT1 inhibitor WZB117. WZB117 treatment of human NSCLC A549 cells resulted in inhibition of glucose uptake, glycolysis and induction of apoptosis and necrosis (1). In addition, WZB-117 reduced tumor growth by more than 70% in an A549 tumor mouse model (1). Through a structure activity relationship (SAR) study of WZB117, a second-generation lead, DRB18, has been identified. DRB-18 is much more stable and 5 to 10 times more potent than WZB117 in inhibiting growth and proliferation in more than 90% of the 60 different cancer cell lines in 9 major cancer types as revealed by NCI-60 screenings. The compound shows particularly higher potency against cell lines with more metastatic potential such as HOP92 (NSCLC) and MDA-MB-231 (TNBC) with IC50 values in high nM range. DRB-18 also demonstrates a favorable liver microsomal metabolic profile and a maximal tolerance dose (MTD). All these indicate that DRB-18 is a potential therapeutic candidate for treating NSCLC and TNBC.

Reference: 1. Liu Y, Cao Y, Zhang W, et al. A small-molecule inhibitor of glucose transporter 1 downregulates glycolysis, induces cell-cycle arrest, and inhibits cancer cell growth in vitro and in vivo. Mol Cancer Ther 2012;11(8):1672-82.

Citation Format: Pratik Shriwas, Yanrong Qian, Xuan Wang, Dennis Roberts, Stephen Bergmeier, Xiaozhuo Chen. New-generation glucose transporter inhibitors targeting non-small cell lung cancer and triple-negative breast 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 2799.