bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1253: Inhibition of FN14 to suppress KRAS-driven lung cancer migration and survival
Authors: Carson Vashti M. , Kim Seungchan , Inge Landon J. , Whitsett Timothy G.
Published: July 2016

Lung cancer remains the leading cause of cancer related mortality throughout the world, and is estimated to kill more than one million people this year. Mutations in KRAS occur in about 1/3 of all lung adenocarcinomas, the most common histologic subtype of lung cancer. Mutations in KRAS are correlated with poor patient prognosis, advanced disease, therapeutic resistance and metastatic outcomes. There is an unmet clinical need to target KRAS-driven NSCLC towards abating the high mortality rate of this disease. We hypothesize that the tumor necrosis factor receptor, FN14 is induced and sustained by mutant KRAS signaling, and represents a therapeutic target in KRAS-driven NSCLC. Employing The Cancer Genome Atlas (TCGA) data, we showed that within a subgroup of adenocarcinoma patients harboring mutant KRAS, elevated FN14 expression conferred significantly worse survival outcomes compared to those with lower FN14 expression. Alone, elevated expression of FN14 conferred a poor prognosis in adenocarcinoma patients compared to lower expression of FN14. In lung cancer cell lines driven by mutant KRAS, elevated FN14 protein expression was observed. The ectopic induction of mutant KRAS in normal rat lung epithelial cells was sufficient to induce FN14 protein expression, an induction dependent on ERK signaling. In an animal model of mutant KRAS-driven NSCLC, FN14 protein was highly expressed and correlated with metastasis in vivo. TWEAK, the only known ligand for FN14, induced migration in NSCLC cell lines harboring mutant KRAS. Conversely, depletion of FN14 expression through siRNA suppressed KRAS-driven cell migration in vitro. We further demonstrated using a clonogenic assay that depletion of FN14 by siRNA was sufficient to reduce KRAS-driven NSCLC cell survival and significantly enhanced the cell killing effects of standard-of-care treatments such as radiation or cisplatin. These data suggest that NSCLC tumors harboring mutant KRAS may be vulnerable to inhibition of FN14 signaling. The recent development of FN14-targeted therapeutics provides an avenue towards clinical utility. As no therapeutics exist to target KRAS directly, a therapeutic strategy targeting FN14 might impact survival in KRAS-driven tumors and reduce the high mortality rate in this subgroup.

Citation Format: Vashti M. Carson, Seungchan Kim, Landon J. Inge, Timothy G. Whitsett. Inhibition of FN14 to suppress KRAS-driven lung cancer migration and survival. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1253.
Abstract 1254: Small molecule targeting of the kRAS mid-G-quadruplex for potential pancreatic cancer therapeutics
Authors: Morgan Rhianna K. , Brooks Tracy A.
Published: July 2016

Pancreatic cancer is disproportionally lethal (7% of all cancer deaths), as compared to its incidence (3% of cancer incidences) within the United States. One of the most important genetic alterations in pancreatic cancer is within the kRAS oncogene. Over 60% of all pancreatic cancers, and up to 95% of pancreatic ductal adenocarcinomas, harbor mutations in this oncogene. While approaches to therapeutically modulate kRAS activity have not yielded clinical agents, downregulation of expression shows promise in preclinical models. To date, no molecular target has allowed for small molecule mediated downregulation of kRAS expression; however, the promoter region holds promise for a new approach. The kRAS promoter has three distinct guanine-rich regions capable of forming higher order non-B-DNA structures, G-quadruplexes (G4s). In particular the middle (mid) of these three regions forms a stable, inducible, and transcriptionally silencing G4 structures, whereas the more distal (far) region forms no such structure, and the more proximal (near) region has little to no biological function. The structure of this mid-region G4 has been elucidated by electromobility shift assay, DMS footprinting, and circular dichroism (CD). Small molecules capable of stabilizing this structure have been screened from the NCI Diversity Set III by the FRET melt assay, confirmed by CD, and examined for their downregulation of kRAS promoter activity. From the 1600 compounds, the indoloquinolone NSC 317605 is the lead molecule identified. It is particularly interesting as it prefers the mid-, as opposed to the near-, G4 and significantly reduces kRAS promoter activity. This is in contrast to the ellipticine NSC 176327, which favors the near-, over the mid-, G4 and does not decrease kRAS promoter activity. The effect of each compound on cell viability on kRAS transcription is under examination in a panel of pancreatic cancer cells. These works support previous findings that the mid-, and not the near-G4, harbors the potential to transcriptionally downregulate kRAS, and identify a new scaffold for future development.

Brooks Lab startup funds, DoD, Rhianna Morgan GSC Grant, University of Mississippi School of Pharmacy

Citation Format: Rhianna K. Morgan, Tracy A. Brooks. Small molecule targeting of the kRAS mid-G-quadruplex for potential pancreatic cancer therapeutics. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1254.
Abstract 1262: Primate-specific estrogen-induced long noncoding RNAs as targets for breast cancer treatment
Authors: Ju Donghong , Xie Daniel , Cai Juan , Goustin Anton Scott , Kosir Mary A. , Lipovich Leonard
Published: July 2016

Purpose: Estrogen is a proliferative hormone that regulates the growth of estrogen receptor positive cells, including breast cancer cells. Although estrogen is a global regulator of protein-coding genes as well as non-coding RNA (ncRNA) genes, its effects on long ncRNA (lncRNA) genes, the most abundant class of human ncRNAs, remain poorly understood. We previously used custom microarrays and Taqman qRTPCR to identify 127 estrogen-responsive lncRNAs, and demonstrated a direct role for 25 of these in breast cancer cell viability and proliferation: estrogen-induced lncRNAs cause cell proliferation (reversed upon siRNA knockdown of these lncRNAs) and estrogen-repressed lncRNAs cause cell death (induced upon overexpression of those lncRNAs).

Furthermore, since over 60% of human lncRNAs, including CR593775, are primate-specific, eight additional primate-specific lncRNAs were used in functional assays to determine whether primate-specific lncRNAs are functional in breast cancer.

Methods/Results: We ablated two new estrogen-induced primate-specific lncRNAs with two independent siRNAs each and validated the knockdowns by qRTPCR. Post-transfection MTT and crystal violet cell proliferation assays revealed that for one lncRNA, both knockdowns reduced cell viability and proliferation. We also used Stellaris RNA fluorescent in situ hybridization (FISH) to determine that the primate-specific estrogen-repressed cell death inducer lncRNA BC041455 is cytoplasmic in MCF7 cells. In addition, CR593775, our top estrogen-induced lncRNA, does not regulate the viability and proliferation of nonmalignant MCF10A breast cells as compared to breast cancer cells that are estrogen receptor positive (T47D, MCF7) and negative (MDA-MB-231).

Conclusion: The primate-specific estrogen-induced lncRNAs are cytoplasmic targets for breast cancer treatment that leads to reduced proliferation and cell viability.

Citation Format: Donghong Ju, Daniel Xie, Juan Cai, Anton Scott Goustin, Mary A. Kosir, Leonard Lipovich. Primate-specific estrogen-induced long noncoding RNAs as targets for breast cancer treatment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1262.
Abstract 1282: Combination of PI3K targeting with cetuximab and irradiation: a preclinical study on an orthotopic xenograft model of head and neck cancer
Authors: Milano Gérard , Bozec Alexandre , Ebran Nathalie
Published: July 2016

The PI3-kinase (PI3K)/AKT/mTOR signaling pathway is of particular interest in head and neck squamous cell carcinoma (HNSCC). Its activation has been identified as an important mechanism implicated in tumor progression and resistance to epidermal growth factor receptor (EGFR) inhibitors. The anti-EGFR monoclonal antibody cetuximab (Cet), radiotherapy (RT) and their combination are widely used in the therapeutic management of patients with HNSCC. Inhibition of the PI3K/AKT/mTOR signaling pathway has been shown to potentialize the effects of anti-EGFR agents and RT. We conducted a preliminary in vitro study demonstrating synergistic effects of Cet followed by the PI3K inhibitor BKM120 (Buparlisib) in both PI3KCA wild-type and mutated cells. The aim of the present study was to investigate the effects of combining BKM120 with Cet and RT on an orthotopic xenograft model of HNSCC.

In the present study we have used an orthotopic (floor of the mouth) model of human HNSCC to measure the effects of a treatment including BKM120 (40 mg/kg, 5 days/week, p.o.), Cet (2,5 mg/kg/day, 1 day/week, i.p.) and RT (6 Gy/dose, 3 days/week), administered alone or in combination. Investigations were performed using the human PI3KCA-mutated (H1047R) HNSCC cell line, CAL33, injected into the mouth floor of nude mice. The tumor growth was followed by IVIS imagery on days 3, 7 and 12 and tumor size was checked with a caliper ruler on day 13 after animal euthanasia.

As compared with the control, the BKM120-Cet and the BKM120-Cet-RT combinations led to the highest tumor inhibition and induced almost complete tumor growth arrest (p < 0.001). The addition of BKM120 and Cet to RT significantly enhanced the impact of RT alone on tumor growth (p < 0.001). The highest inhibitory effects of treatments on cell proliferation (Ki67 labelling), MAPK (pERK labelling) and PI3K/AKT/mTOR (pS6R labelling) signaling pathways were found with the BKM120-Cet association. RT alone (p = 0.10) tended to activate the MAPK pathway but the association of BKM120 and Cet to RT inhibited the RT-induced activation of the MAPK pathway (p = 0.03).

In conclusion, in this orthotopic HNSCC model, the combination of BKM120 with Cet and RT produced synergistic effects on tumor growth. These results could serve as a strong preclinical basis for innovative treatments combining PI3K inhibition with anti-EGFR therapies and RT in patients with HNSCC.

Citation Format: Gérard Milano, Alexandre Bozec, Nathalie Ebran. Combination of PI3K targeting with cetuximab and irradiation: a preclinical study on an orthotopic xenograft model of head and neck cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1282.
Abstract 1286: Cytokine response of stromal cells to prostate cancer chemotherapeutics
Authors: Gales Dominique , Yates Clayton C. , Samuel Temesgen
Published: July 2016

Non-responsiveness to chemotherapeutic drugs presents a significant challenge to the effective treatment of advanced prostate cancer. Exploration of the therapeutic response in prostate cancer has largely focused on the epithelial tumor cells. However, evidence suggests that the tumor microenvironment may modulate response to chemotherapeutics. The tumor microenvironment consists of immune, fibroblastic, and vascular cells, as well as extracellular matrix (ECM) and stromal-derived soluble factors, all of which contribute to interactions within the tumor microenvironment. It has been demonstrated that tumor cells cross-talk with stromal cells, to establish a protective niche at primary and distant sites and to facilitate survival of cancer cells. Such tumor-stroma cell cross-talk often involves secreted factors, such as cytokines. Previous studies have illustrated the importance of cytokines and cytokine receptors as modulators of drug response. In this study, we sought to identify cytokine factors expressed in response to drugs clinically used to control prostate cancer. To obtain the expression profiles, we conducted a human cytokine and chemokine array, which consisted of 84 specific genes. Analysis of the prostate cancer and stromal cells treated with Docetaxel (4nM), Enzalutamide (30μM) and Bicalutamide (30μM) revealed differential expression patterns. The effect of chemotherapeutics on the expression of the cytokine IL-16 and its cognate receptors CD9 and CCR5 in prostate cancer and stromal cell lines was further examined. We found IL-16 expression increased several fold following chemotherapeutic treatment in stromal cell lines compared to prostate cancer cell lines. To validate gene expression, we examined the expression of IL-16 and its receptors by RT-PCR. All experiments were performed in triplicates. Student t- tests were used to determine the statistical significance between groups. IL-16 expression increased following exposure to chemotherapeutics in stromal cell lines. CCR5 expression showed a decrease in PC3 prostate cancer cells but no significant changes were observed in LNCaP cells. CD9 expression showed an increase in both LNCaP and PC3 cell lines. Collectively, these results indicate that chemotherapy of prostate cancer may alter the expression of IL-16 and its receptors. We hypothesize that IL-16 is a soluble stromal factor that is expressed in response to anticancer drugs, and may have paracrine activity on neighboring cells that express the cognate receptors.

Citation Format: Dominique Gales, Clayton C. Yates, Temesgen Samuel. Cytokine response of stromal cells to prostate cancer chemotherapeutics. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1286.
Abstract 1288: Targeting the Hippo pathway in NF-2 deficient papillary kidney cancers
Authors: Sourbier Carole , Liao Penny , Ricketts Christopher J. , Wei Darmood , Yang Youfeng , Baranes Sarah M. , Kijima Toshiki , Krane Louis S. , Boufraqech Myriem , Ohanjanian Lernik , Gibbs Ben , Wei Ming-Hui , Neckers Len , Vocke Cathy D. , Linehan. W. Marston
Published: July 2016

About 10% of papillary renal cell carcinomas (PRCC) bear mutations in NF2 or SAV1, two members of the Hippo pathway, which controls cell growth by regulating the transcriptional activity of YES1-Associated Protein YAP1. NF2 or SAV1 mutations lead to aberrant YAP1 activation resulting in cell proliferation and anti-apoptotic signals. The src family kinase YES1 is a known regulator of YAP1 transcriptional activity in the context of β-catenin-dependent tumors. Dasatinib and saracatinib are 2 src inhibitors that have shown to also have potent inhibitory effects on YES1. We hypothesized that inhibition of the Hippo pathway might provide a valuable therapeutic approach for patients with PRCC tumors bearing NF2 mutation, and that inhibiting YES1 might inhibit YAP1 in PRCC. Our data demonstrate that inhibition of the Hippo pathway is lethal to NF2-deficient PRCC cell lines, and that inhibiting YES1 with dasatinib or saracatinib effectively inhibits YAP1 and its downstream targets BIRC5 (survivin), CCND1 (cyclin D1) and CTGF (CTGF). Further, dasatinib proves to have an anti-tumor effect in vivo and was cytotoxic in vivo and in vitro, causing G0-G1 cell cycle arrest in NF2-deficient PRCC cell lines. Thus, inhibiting YES1 and the subsequent transcriptional activity of YAP1 with dasatinib or saracatinib might be a viable therapeutic approach for NF2-deficient PRCC tumors.

Citation Format: Carole Sourbier, Penny Liao, Christopher J. Ricketts, Darmood Wei, Youfeng Yang, Sarah M. Baranes, Toshiki Kijima, Louis S. Krane, Myriem Boufraqech, Lernik Ohanjanian, Ben Gibbs, Ming-Hui Wei, Len Neckers, Cathy D. Vocke, W. Marston Linehan. Targeting the Hippo pathway in NF-2 deficient papillary kidney cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1288.
Abstract 129: Integrated genomic analysis of survival outliers in glioblastoma
Authors: Peng Sen , Dhurv Harshil , Armstrong Brock , Kiefer Jeffrey , Salhia Bodour , Ross Julianna , Legendre Christophe , Virk Selene , Sloan Andrew E. , Ostrom Quinn T. , Barnholtz-Sloan Jill , Tran Nhan L. , Berens Michael E.
Published: July 2016

Despite the general poor prognosis for patients with GBM, a proportion survives well beyond the median survival of 12-14 months following diagnosis. To elucidate molecular features associated with disproportionately protracted survival, we conducted deep genomic comparative analysis of a cohort of patients receiving standard therapy (surgery plus concurrent radiation and temozolomide) wherein “GBM outliers” were identified: patients who responded (long-term survivor, LTS) versus those who failed rapidly (short-term survivor, STS). The datasets enabled interrogation for signatures indicative of tumor vulnerability. Whole genomic, transcriptomic and epigenetic analyses of 18 patients, including 8 LTS with an average 30 months overall survival (OS) and 10 STS with an average of 7 months OS were performed to capture single nucleotide variants (SNVs), indels, translocations, intra-chromosomal rearrangements, copy number variants, along with DNA methylation and mRNA expression. LTS and STS cases showed equal proportion of 7p11.2 (EGFR) amplification and 9p21.3 (CDKN2A) deletion. However, LTS GBM showed frequent chromosomal gains in 4q12 (PDGFRA and KIT) and 12q14.1 (CDK4) and deletion in 19q13.33 (BAX, BCAT2 and CD33), whereas, STS GBM showed frequent deletion in 9p11.2 (FOXD4L2 and AQP7P3) and 22q11.21 (HIC2). In addition, LTS GBM showed a 2-fold increased copy number alteration (specifically deletion) as compared to STS GBM. By gene expression analysis, supervised clustering using the CIN70 signature (prognostic) showed an increased expression in STS GBM. Overall, whole genome methylation analyses showed that STS GBM tumors harbor more hypomethylation in probes situated in -200 bp of transcription start site (TSS) and both exon 1 and 5’UTR region. A methylation signature consist of 89 probes distantly separate LTS from STS GBM tumors. We posit that genomic instability (broadly inclusive) is associated with vulnerability of GBM to standard therapy; conversely, genomic instability coupled with genetic and epigenetic signatures may identify patients where up-front entry into alternative, targeted regimens would be a preferred, more-efficacious management.

Supported by a grant from the Ben & Catherine Ivy Foundation.

Citation Format: Sen Peng, Harshil Dhurv, Brock Armstrong, Jeffrey Kiefer, Bodour Salhia, Julianna Ross, Christophe Legendre, Selene Virk, Andrew E. Sloan, Quinn T. Ostrom, Jill Barnholtz-Sloan, Nhan L. Tran, Michael E. Berens. Integrated genomic analysis of survival outliers in glioblastoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 129.
Abstract 1290: Actinomycin D enhanced immunotoxin RG7787 killing of cancer cells
Authors: Liu Xiu Fen , Xiang Laiman , Prunotto Marco , Niederfellner Gerhard , Pastan Ira
Published: July 2016

Immunotoxins are recombinant fusion proteins that contain an antibody fragment directed against a tumor selective surface antigen attached to a protein toxin. RG7787 is a newly developed, mesothelin-targeted immunotoxin designed to be less immunogenic and better tolerated than the previous clinical candidate SS1P. The targeting moiety of RG7787 consists of a humanized anti-mesothelin Fab, while its effector moiety is a truncated portion of Pseudomonas exotoxin A (PE) consisting essentially only of the catalytic domain III fused via a furin cleavable linker to the Fab fragment. The domain III variant used in RG7787 contains mutations that silence all known human B-cell and some T-cell epitopes. RG7787 targets and kills mesothelin-positive tumor cells, which are prevalent in mesothelioma, ovarian, lung, and pancreatic cancers. Safety and immunogenicity of RG7787 are being assessed in these tumor indications in an ongoing phase I trial. In order to further enhance the anti-tumoral activity of RG7787, we screened for clinically used drugs that can synergize with RG7787 in vitro and/or in vivo. Actinomycin D (Act D) is a potent transcription inhibitor and is used for treating a variety of cancers, including gestational trophoblastic neoplasia, Wilms tumor, rhabdomyosarcoma, and Ewing's sarcoma. In this study we found that the combination of Act D with RG7787 greatly stimulated cell killing of mesothelin positive cell lines, such as KB31, KLM1, and Hay. The combination also produced complete regressions of KLM1 pancreatic tumor xenografts in mice. To investigate the mechanism of killing we used an apoptosis RNA array and found that both Act D and RG7787 stimulate apoptotic stress responsive genes including TNFα, TRAILR2 (DR5), NFκB, GAD45A and TP53. The combination also increased cleavage and activation of the pro-apoptotic proteins caspase-3, -9, and PARP. Taken together our data indicate that combining RG7787 and Act D reduces the threshold for activation of apoptosis in cancer cells.

Citation Format: Xiu Fen Liu, Laiman Xiang, Marco Prunotto, Gerhard Niederfellner, Ira Pastan. Actinomycin D enhanced immunotoxin RG7787 killing of cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1290.
Abstract 1291: Applicability of integrative tumor response assays for recurrent colorectal cancer
Authors: Yoon Yong Sik , Kim Jin Cheon
Published: July 2016

Introduction

Drug response assays use autologous viable tumors to evaluate susceptibility to specific agents in vitro. Histoculture drug reponse assay (HDRA) is a representative methyl thiazolyl-diphenyl-tetrazolium bromide (MTT) assay, which has the advantage of more correctly reflecting the in vivo microenvironment. Many studies showed 66-92% of accuracy rates for clinical correlation of chemotherapy in solid tumors including colorectal cancer (CRC). However, in recurrent cases of metastatic CRC, there is no usable assay to predict second-line chemo-sensitivity. Thus, authors invented novel technique, the integrative tumor response assay (ITRA), can identify drug responses for both first- and second-line chemotherapy simultaneously. We investigated the chemo-sensitivity to clinically used regimens using ITRA of samples from patients with metastatic CRC, and compared their chemo-sensitivity with the observed clinical response.

Methods

A total of 129 patients with metastatic CRC were prospectively enrolled. First-stage HDRAs were performed using 5-fluorouracil with leucovorin and oxaliplatin (FX) or irinotecan (FR). Second-stage HDRAs (ITRA) were done for survived cells after first-stage HDRA, using FX, FR, and their combinations with bevacizumab and cetuximab. The inhibition rate of tumor growth (IR) cut-off value for a positive response was determined to be ≥ 30%. For clinical validation, treatment responses of chemotherapy were evaluated using the Response Evaluation Criteria in Solid Tumors (RECIST). The primary endpoint of this study was a correlation between the ITRA results and the clinical response in the response rate (RR). This was defined as positive for the effect of chemotherapy for tumor responses between complete response (CR) and partial response (PR).

Results

Among 129 used samples, ITRA failure was 9 (7%), due to deficient volume of samples. Out of 79 evaluated first-line chemotherapeutic regimes, RR was 53% (42/79). The correlation rate of HDRA for first-line chemotherapy was 70.9% (56/79), with a 71.4% (30/42) of sensitivity and 70.3% (26/37) of specificity. For 42 cases completing second-line chemotherapy, RR was 43% (18/42). The accuracy rate of ITRA for second-line chemotherapy was 61.9% (26/42), with a 44.4% (8/18) of sensitivity and 75% (18/24) of specificity.

Conclusions

ITRA might be further developed to be a feasible and useful technique for predicting therapy efficacy and selecting the appropriate anticancer regimen for individual patients despite its relatively low accuracy.

Citation Format: Yong Sik Yoon, Jin Cheon Kim. Applicability of integrative tumor response assays for recurrent colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1291.
Abstract 1292: Camalexin, an indole phytoalexin from Arabidopsis thaliana, displays activity against ovarian cancer stem cells
Authors: Mezencev Roman , McDonald John F.
Published: July 2016

Ovarian cancer is the most lethal of all gynecological cancers. Current treatment of advanced ovarian cancers, which includes debulking surgery and chemotherapy, is initially effective in majority of patients; however, 70-90% of them eventually develop disease recurrence with limited treatment options. This recurrence can be attributed to therapy-resistant cancer stem cells (CSC), which represent a subset of all malignant cells that form the bulk of ovarian cancers. CSC may remain as a minimal residual disease after the bulk of ovarian tumor mass has been removed by surgery and/or chemotherapy; therefore, there is considerable current interest in the development of new therapies that can effectively target this insidious subpopulation of tumor cells. Here we report on the anticancer activity of camalexin, a major indole phytoalexin of Arabidopsis thaliana, against ovarian cancer stem cells. We demonstrate that camalexin inhibits proliferation and induces cell death in ovarian cancer stem cells that exhibit various molecular mechanisms of anticancer drug resistance. Furthermore, we present the mode of action of this prospective anticancer agent identified by combined approach that included in silico predictions, comprehensive analysis of whole-genome gene expression data and target-specific assays. Lastly, we demonstrate the relevance of the identified mode of action in context of ovarian cancer cell signaling.

Citation Format: Roman Mezencev, John F. McDonald. Camalexin, an indole phytoalexin from Arabidopsis thaliana, displays activity against ovarian cancer stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1292.
Abstract 1296: Vascular shutdown anti-tumor effect of tetra-arsenic oxide on cervical cancer cells
Authors: Kim. Yong-Wan
Published: July 2016

Background: Tetra arsenic oxide (As4O6) is a novel arsenic compound that exhibits potent anti-vascular activity and significantly suppresses solid tumor growth. The present study was conducted to investigate the vascular shutdown effects in HPV E6/E7-expressing tumors bearing mice.

Methods: After tumors reached 300-350 mm3 in volume, mice were randomly divided into four groups and treated intraperitoneally with three different dose of As4O6 at 1-week interval. Tumor blood perfusion and vascularity were visualized using Hoechst 33342, CD31 staining respectively from 1 hour to 1 week after As4O6 treatment. Histopathological features were observed following hematoxylin and eosin staining. Apoptosis, TNF-a, caspase activity and tumor regression were used to determine the mechanisms for vascular shutdown effects.

Results: As4O6 significantly suppressed tumor growth compared with control group. This tumor growth inhibition led to massive necrosis and vascular shutdown in tumor tissue, and also tumor tissue necrosis and apoptosis. Mice treated with As4O6 had a reduction in tumor vessel dimensions compared with the control animals, with CD31 stained microvessels still being apparent at the outer edge of the tumor. Additionally, in the control group, vessel area and diameter increased over time, whereas in the tumors from the As4O6-treated group, vessel area and diameter remained stable or decreased. Apoptotic cell populations induced by As4O6 were increased by double staining the TC-1 cells with annexin V and propidium iodide.

Conclusions: The results suggest that As4O6 has potential anticancer activity that is exerted by vascular shutdown in C57BL/6 mice transplanted with TC-1 cells. The study is novel in the observation of recovery of disturbed vascular function.

Citation Format: Yong-Wan Kim. Vascular shutdown anti-tumor effect of tetra-arsenic oxide on cervical cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1296.
Abstract 1317: IT-143: A nanoparticle delivery platform that encapsulates daunorubicin and widens therapeutic window
Authors: Costich Tara Lee , Crouse Rick , Carie Adam , Buley Taylor , Ellis Tyler , Repp Lauren , Semple J.Edward , Vojkovsky Tomas , Bakewell Suzanne , Sill Kevin
Published: July 2016

Daunorubicin is an anthracycline family chemotherapeutic with a narrow therapeutic window. Employing our nanoparticle drug delivery platform we encapsulated daunorubicin non-covalently in the hydrophobic core of a polymer micelle (IT-143). IT-143 is a nanoparticle formulation comprised of a hydroxamic acid triblock polymer with ferric crosslinking that increases stability for improved drug circulation and results in a pH dependent release of the encapsulated daunorubicin. Formulation characterization demonstrates a 3.7% weight loading (v/v) of daunorubicin resulting in an average micellar size of 58 nm. In vitro cytotoxicity is comparable to daunorubicin free drug with an IC50 ranging between 60-100 nM, dependent on cell line, compared to 67-114 nM for daunorubicin. In vivo we compared IT-143 plasma pharmacokinetics to daunorubicin administered as free drug and the Cmax was extended from 0.18 μg/mL for daunorubicin to 27.0 μg/mL for IT-143 at the 3 mg/kg dose, and to 49.4 μg/mL at the 6 mg/kg dose. We increased the maximum tolerated dose (MTD) from 7.5 mg/kg to 17.5 mg/kg in mice and improved anti-tumor efficacy. Furthermore, IT-143 eliminated in vivo toxicity compared to equivalent daunorubicin dosed at its MTD. Efficacy studies in 3 xenograft models (HCT116, HT-1080 and HOS-MNNG) compared intravenous bolus administration of IT-143 at equivalent and equitoxic dose to daunorubicin treatment. IT-143 inhibited HCT116 colorectal tumor volume growth by 21% compared to 7% at the equivalent daunorubicin dose, and by 51% at the 17.5 mg/kg dose. In the HT-1080 fibrosarcoma model IT-143 inhibited tumor volume by 38% compared to 37% inhibition at the equivalent daunorubicin dose, and by 94% at the 17.5 mg/kg dose. In the HOS-MNNG osteosarcoma model IT-143 did not inhibit tumor volume compared to 21% inhibition at the equivalent daunorubicin dose, but inhibited tumor volume by 34% at the 17.5 mg/kg dose. The encapsulation of daunorubicin as IT-143 exhibits increased dosage of daunorubicin with decreased toxicities not possible with free daunorubicin. These studies indicate that IT-143 widens the therapeutic window of daunorubicin treatment, providing a safer way to reduce patient toxicity yet increasing antitumor efficacy.

Citation Format: Tara Lee Costich, Rick Crouse, Adam Carie, Taylor Buley, Tyler Ellis, Lauren Repp, J.Edward Semple, Tomas Vojkovsky, Suzanne Bakewell, Kevin Sill. IT-143: A nanoparticle delivery platform that encapsulates daunorubicin and widens therapeutic window. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1317.
Abstract 132: Comprehensive genomic analysis of human papillomavirus-associated oral cancers
Authors: Symer David E. , Akagi Keiko , Coombes Kevin R. , Xiao Weihong , Pickard Robert K. L. , Agrawal Amit , Gillison Maura L.
Published: July 2016

Human papillomavirus-associated oral cancers comprise a distinct disease that is increasing in frequency in Western countries. Recent genomic landscape studies of oral cancers and of HPV-associated cervical cancers identified the most commonly mutated genes in each. Here we report a comprehensive analysis of 83 HPV-positive oropharyngeal cancers studied by whole genome sequencing (WGS), and an additional 46 tumors evaluated by the Cancer Genome Atlas project (TCGA) by exome sequencing. We confirmed recurrent mutations in previously reported, frequently mutated candidate driver genes including PIK3CA, as well as several novel gene targets, each occurring recurrently at frequencies of more than approximately 3%. Our WGS data demonstrated recurrent focal genomic instability associated with HPV insertional mutagenesis. We observed dramatic changes in genomic copy number variants (CNVs) at chromosome 3q as well as numerous other chromosomal regions that are recurrently gained or lost in HPV-positive tumors. RNA-Seq data from this collection of oral cancers defined differentially expressed transcript levels and other molecular alterations associated with single nucleotide variants (SNVs), CNVs and other genomic structural variants in the tumors. Together, our results reveal a unique pattern of somatic variants that distinguishes HPV+ oral cancers both from HPV- oral cancers as well as other HPV+ tumors arising in distinct tissues including the uterine cervix. These data shed new light on the molecular pathogenesis of oral cancers, and provide new opportunities for development of diagnostic and therapeutic strategies for affected patients.

Citation Format: David E. Symer, Keiko Akagi, Kevin R. Coombes, Weihong Xiao, Robert K. L. Pickard, Amit Agrawal, Maura L. Gillison. Comprehensive genomic analysis of human papillomavirus-associated oral cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 132.
Abstract 1321: IT-147: A stabilized polymer micelle formulation of epothilone D for treatment of solid tumors
Authors: Carie Adam , Buley Taylor , Sullivan Bradford , Semple J.Edward , Ellis Tyler , Costich Tara Lee , Sethuraman Jyothi , Crouse Rick , Sill Kevin , Bakewell Suzanne
Published: July 2016

IT-147 is a formulation of epothilone D encapsulated in a stabilized polymer micelle. Epothilones are a class of cytotoxic chemotherapeutics that induce apoptosis via microtubule stabilization. Epothilone D is a poor substrate for P-glycoprotein efflux pumps and has demonstrated equivalent activity against drug-sensitive and multidrug-resistant human cancer cell lines. This offers a distinct advantage over other microtubule stabilizing agents such as taxanes, however clinical utility is limited by a narrow therapeutic window due to dose limiting toxicities such as peripheral sensory neuropathy, GI toxicities, and cognitive abnormalities. We have optimized a lead formulation comprising 2% epothilone D (w/w) encapsulated in a polymer micelle that is crosslinked with iron to provide micelle stability upon dilution. IT-147 has an average diameter of 70 nm. The iron-mediated crosslinking provides pH-dependent release of epothilone D such that drug can be released in the tumor microenvironment as well as in the endosome/lysosome upon cellular entry. In addition, the geometrical arrangement of iron molecules around the core of the micelle imparts superparamagnetic properties that allow for imaging of intact nanoparticles by MRI. IT-147 demonstrates a low nanomolar IC50 against a panel of human cancer cell lines in vitro. In vivo, IT-147 demonstrates a 4-fold increase in maximum tolerated dose in a mouse model compared to epothilone D free drug. Pharmacokinetics (PK) in a cannulated rat model for a 20 mg/kg epothilone D dose demonstrates a 6.5-fold increase in area under the time versus concentration curve (AUC), and a 14.3-fold increase in the terminal half-life compared to free drug. Dose escalation of IT-147 to 30 and 40 mg/kg epothilone D in the rat PK model results in linear increases in AUC from 53.5 h*μg/mL at 20 mg/kg to 82.9 and 110.8 h*μg/mL at 30 and 40 mg/kg, respectively. Treatment with IT-147 at the MTD in an HCT116 tumor xenograft model led to tumor stasis during the course of treatment, and MRI imaging of mice treated with IT-147 demonstrates tumor accumulation over 24 and 48 hours post administration. Taken together, data for IT-147 demonstrates successful encapsulation of epothilone D leading to a safer, more effective formulation with the potential for MRI imaging as a predictor for response.

Citation Format: Adam Carie, Taylor Buley, Bradford Sullivan, J.Edward Semple, Tyler Ellis, Tara Lee Costich, Jyothi Sethuraman, Rick Crouse, Kevin Sill, Suzanne Bakewell. IT-147: A stabilized polymer micelle formulation of epothilone D for treatment of solid tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1321.
Abstract 133: Integrated molecular characterization of uterine carcinosarcoma in The Cancer Genome Atlas (TCGA) project
Authors: Akbani Rehan ,   The Cancer Genome Atlas Research Network, Levine Douglas A.
Published: July 2016

We used array- and sequencing-based technologies to perform an integrated genomic, epigenomic, transcriptomic, and proteomic characterization of the rare tumor type uterine carcinosarcoma (UCS) within the context of The Cancer Genome Atlas (TCGA) project using 57 cases that had stringent histopathologic review. Cohort samples had extensive copy number alterations and highly recurrent somatic mutations. Nearly all (91%) cases had TP53 mutations, similar to ovarian and serous uterine carcinomas, and frequent mutations were also found in PTEN, PIK3CA, PPP2R1A, FBXW7, and KRAS, similar to endometrioid and serous uterine carcinomas. Transcriptome sequencing identified a strong EMT gene signature in a subset of 17 (30%) cases, and cases with EMT signatures had decreased expression of mir-200 family members that was attributable to epigenetic alterations at miRNA promoters. The range of EMT signatures scores in UCS was the largest among all the TCGA tumor types studied. UCS shared proteomic features with both gynecologic carcinomas and non-gynecologic mesenchymal-like tumors. Our results indicate that UCS tumors share many features with serous-like endometrial carcinomas, including frequent TP53 mutations and extensive somatic copy number alterations, though with greater EMT features. Multiple somatic mutations and copy number alterations in genes that are therapeutic targets were identified. There was a high degree of mutational clonality, consistent with tumors being derived from a single cell of origin. Taken together, these data suggest that while some UCS tumors develop from an endometrioid lineage, the majority likely de-differentiate from a serous precursor, potentially accounting for their clinical aggressiveness and poor response to treatment.

Citation Format: Rehan Akbani, The Cancer Genome Atlas Research Network, Douglas A. Levine. Integrated molecular characterization of uterine carcinosarcoma in The Cancer Genome Atlas (TCGA) project. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 133.
Abstract 1338: Ferulic acid as a natural bioactive compound enhances PARP inhibitor sensitivity in breast cancer cells
Authors: Park Eunmi , Lee Hyuna
Published: July 2016

Homologous-recombination (HR)-dependent repair defective cells are hypersensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. Combinations of defective HR pathway and PARP inhibitors have been an effective chemotherapy strategy. We previously showed that knockdown of the WD40-repeat containing protein, Uaf1, is HR repair defect in mouse embryo fibroblast cells and is sensitive to ABT-888, a chemotherapy drug commonly used for inhibiting PARP. Consistent with the HR defective mouse genetic study, here, we show that ferulic acid inhibits Rad 51 foci formation and accumulates γ-H2AX in breast cancer cells. Ferulic acid treatment reduces HR repair and causes breast cancer cells to become hypersensitive to ABT-888 treatment. Our study indicates that ferulic acid with PARP inhibitor treatment may be useful for the combination chemotherapy as a natural bioactive compound.

Citation Format: Eunmi Park, Hyuna Lee. Ferulic acid as a natural bioactive compound enhances PARP inhibitor sensitivity in breast cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1338.
Abstract 1343: P32-targeting TT1 peptide delivers nanoparticles to intracranial glioblastomas
Authors: Säälik Pille , Hunt Hedi , Tobi Allan , Willmore Anne-Mari Anton , Toome Kadri , Sharma Shweta , Kotamraju Ramana , Bergers Gabriele , Bjerkvig Rolf , Ruoslahti Erkki , Teesalu Tambet , Teesalu Tambet
Published: July 2016

Targeted delivery of cancer therapeutics using affinity ligands can dramatically improve antitumor efficacy. Over the years a number of homing peptides that upon systemic injection accumulate in solid tumors have been identified by in vivo peptide phage display. In a quest to find homing peptides optimally suited for drug delivery to high-grade gliomas, our laboratories are using advanced mouse models of glioblastoma (GBM) to systematically audit known tumor-homing peptides and to perform new in vivo screens using peptide phage libraries.

P32 is a mitochondrial chaperone that is aberrantly expressed on the cell surface in activated malignant and stromal cells in tumors. P32 is a receptor for widely used LypP-1 peptide and for recently identified TT1 peptide. Here we show that iron oxide nanoworms (IONW) functionalized with linear TT1 peptide (CKRGARST) strongly home to intracranial GBMs grafted in immune deficient mice. IONW are paramagnetic nanoparticles that are PEGylated to extend blood half-life, and have, because of their elongated shape, more effective targeting properties than spherical nanoparticles. Five hours after intravenous injection of IONW (7.5 mg/kg), macroscopic fluorescence imaging demonstrated robust homing of TT1-IONW in GBMs of murine origin (WT GBM and VEGF KO GBM from the G. Berger lab) and in a patient-derived glioma model (P13 model from the Bjerkvig lab). Confocal microscopy confirmed the presence of TT1 but not control IONW in gliomas, with TT1-IONW signal showing partial overlap with blood- and lymphatic vessel markers (CD31 and LYVE-1) in WT GBM and P13 gliomas, whereas lower level of colocalization with these markers was detected for mouse GBM not expressing VEGF. In addition, moderate colocalization between TT1-IONW and the macrophage marker CD11b was detected in the P13 tumors. Detailed phenotyping and functional characterization of TT1-positive macrophages is ongoing.

Our data suggest that TT1 peptide has potential applications as a glioma-targeting vehicle. Currently, we are evaluating TT1-targeted IONWs as a contrast agent for glioma MRI and as carriers for cytotoxic compounds.

Citation Format: Pille Säälik, Hedi Hunt, Allan Tobi, Anne-Mari Anton Willmore, Kadri Toome, Shweta Sharma, Ramana Kotamraju, Gabriele Bergers, Rolf Bjerkvig, Erkki Ruoslahti, Tambet Teesalu, Tambet Teesalu. P32-targeting TT1 peptide delivers nanoparticles to intracranial glioblastomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1343.
Abstract 1352: High-throughput matrix screening reveals synergistic chemotherapeutic combinations with blockade of CD47 to enhance cytotoxicity in breast cancer
Authors: Roberts David D. , Smith Ashley , Sipes John M. , Wilson Adam , Mathews-Griner Lesley , Guha Rajarshi , Thomas Craig J. , Ferrer Marc , Soto-Pantoja David R.
Published: July 2016

CD47 is a widely expressed cell surface receptor that serves as a counter-receptor for SIRPα in recognition of self by the innate immune system. On the other hand CD47 also serves as a signaling receptor for the matricellular protein thrombospondin-1 (TSP-1), regulating cell growth and survival. Clinical studies consistently show that increased expression of CD47 is an independent poor prognosis factor in several types of cancer, including breast cancer. Moreover elevated expression of CD47 is associated with development of resistance to chemotherapy by inhibiting cell death pathways. Therefore, agents targeting CD47 are attractive to overcome therapeutic resistance in breast cancer. Using a high-throughput assay in a 1536-well microplate format we screened a comprehensive set of approved and late stage development oncology drugs in combination with an anti-CD47 morpholino to find combinatorial strategies that are more cytotoxic against breast cancer cells. Potency and efficacy measurements during the primary screen identified compounds that synergized with anti-CD47 to augment their cytotoxicity effect. One of the compound groups that demonstrated increased synergism with CD47 were the anthracycline family of drugs. We further validated these results in a syngeneic model of breast cancer and demonstrated that blockade of CD47 in combination with doxorubicin improves chemotherapeutic response when compared to mice administered doxorubicin alone. Furthermore the anti-tumor response with anti-CD47 combination is associated with a reduction in glycolytic flux and a selective up regulation of mitophagy. Overall this indicates that blockade of CD47 in the clinic may synergize with chemotherapeutic strategies to improve patient curative responses.

Citation Format: David D. Roberts, Ashley Smith, John M. Sipes, Adam Wilson, Lesley Mathews-Griner, Rajarshi Guha, Craig J. Thomas, Marc Ferrer, David R. Soto-Pantoja. High-throughput matrix screening reveals synergistic chemotherapeutic combinations with blockade of CD47 to enhance cytotoxicity in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1352.