bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 969: Tunneling nanotubes, a novel mode of tumor cell-macrophage communication in tumor cell invasion
Authors: Hanna Samer , McCoy-Simandle Kessler , Leung Edison , Condeelis John , Cox Dianne
Published: August 2018

The interaction between tumor cells and macrophages is crucial in promoting tumor invasion and metastasis. These two cell types are engaged in a mutual interaction in which tumor-associated macrophages produce epidermal growth factor (EGF) to activate tumor cells. In turn, tumor cells produce colony-stimulating factor-1 (CSF-1) that stimulates macrophages. The tumor cell - macrophage pairs formed in response to this paracrine signaling are then attracted toward blood vessels under an endothelial cell produced HGF gradient. This mutual signaling interaction leads to the co-migration and invasion of both cell types as imaged both in vitro and in vivo.  . Recent studies have revealed an additional novel mechanism of intercellular communication between macrophages that can transmit signals over long distances through membranous actin-based tunneling nanotubes (TNTs). Our data demonstrates that heterotypic TNTs form between macrophages and tumor cells in co-culture. This novel interaction induced changes in tumor cell morphology consistent with a more invasive phenotype which was dependent on EGF-EGFR signaling. Moreover, the presence of these heterotypic TNTs was important for tumor cell invasion in an in vitro 3D invasion assay. Furthermore, reduction of M-Sec (TNFAIP2) in macrophages, a protein involved in TNT formation, inhibited tumor cell elongation and blocked the ability of tumor cells to invade. Using a modified 1D assay that mimics macrophage-dependent tumor cell streaming observed in vivo, we show a significant increase in long distance directional migration of tumor cells towards an endothelial-coated bead in a TNT dependent manner. We also employed an in vivo zebrafish model that recreates macrophage mediated tumor cell invasion in a more physiological fashion. The presence of macrophages increased tumor spread from the injection site, number of metastatic foci, and the distance of metastatic spread in a macrophage TNT-dependent manner. Overall, our studies support a role for TNTs as a novel means of interaction between tumor cells and macrophages that may lead to tumor progression and metastasis.

Citation Format: Samer Hanna, Kessler McCoy-Simandle, Edison Leung, John Condeelis, Dianne Cox. Tunneling nanotubes, a novel mode of tumor cell-macrophage communication in tumor cell invasion [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 969.
Abstract 971: Three-dimensional gene regulatory landscapes in normal and cancer cells
Authors: Abraham Brian J. , Guo Yang Eric , Hnisz Denes , Li Charles H. , Weintraub Abraham S. , Day Daniel S. , Schuijers Jurian , Lee Tong Ihn , Young Richard A.
Published: August 2018

Key oncogenes can be misregulated in tumor cells by the acquisition of tumor-specific enhancers that direct gene expression through physical contacts (1,2). Identifying the full complement of enhancers regulating each oncogene could identify additional vulnerabilities in tumor expression programs, but remains challenging, because a given enhancer can regulate multiple genes and each of its targets may be genomically distant. Here we use DNA interaction data to construct gene regulatory landscapes for all expressed genes in a tumor cell and demonstrate that sets of enhancers can be assigned to these oncogenes using direct looping and insulated neighborhood data. A subset of these landscapes contains an exceptional amount of transcriptional apparatus, reminiscent of SEs (3), so we term this subset 3D-SEs. Well-characterized oncogenes, including c-Myc, acquire 3D-SEs in tumor cells where a c-Myc¬-associated linear SE was not identified, suggesting SE acquisition by c-Myc and other oncogenes has been underestimated. Each gene's regulatory network can also surprisingly extend beyond the confines of insulated neighborhoods and incorporate additional distal enhancers. Visualizing instances of 3D-SEs with microscopy demonstrates that they are components of liquid-liquid phase-separated bodies in cells, suggesting gene regulatory landscapes underpin these transcriptional condensates. The interactions comprising gene regulatory networks and their target genes thus extend previous interpretations of the targets of enhancers, signaling pathways, and disease-associated enhancer variants.

References: 1. Hnisz, Abraham, Lee, et al. and Young, Cell 2013. 2. Mansour, Abraham, et al. and Young and Look, Science 2014. 3. Whyte, Orlando, Hnisz, Abraham, et al. and Young, Cell 2013.

Citation Format: Brian J. Abraham, Yang Eric Guo, Denes Hnisz, Charles H. Li, Abraham S. Weintraub, Daniel S. Day, Jurian Schuijers, Tong Ihn Lee, Richard A. Young. Three-dimensional gene regulatory landscapes in normal and cancer 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 971.
Abstract 993: Wnt-er is coming: WNT5A promotes a slow cycling phenotype via p53 in conditions of stress
Authors: Webster Marie R. , Fane Mitchell , Kaur Amanpreet , Alicea Gretchen , Ecker Brett L. , Ndoye Abibatou , Kugel Curtis , Basu Subhasree , Valiga Alexander , Appleton Jessica L. , Murphy Maureen E. , Weeraratna Ashani
Published: August 2018

Resistance to targeted therapy and chemotherapy increases with age. Previously, we found that aged skin fibroblasts secrete sFRP2, which decreases ß-catenin, MITF, and APE1 in melanoma cells, and promotes invasion. Loss of APE1, a key redox effector, increased DNA damage in melanoma cells and caused the cells to become resistant to targeted therapy. Here we show that the aging tumor microenvironment drives a slow cycling phenotype in melanoma cells via WNT5A and p53. We found WNT5A expression in melanoma cells correlates with p53 expression and a higher percent of slow cycling cells. Knocking down WNT5A decreases both p53 expression and the percent of slow cycling cells. When we isolated slow cycling cells by flow cytometry, we found that they have increased WNT5A, p53, and p21 expression. Analysis of patient tumors in the TCGA data base revealed that patients with higher than average p53 expression, also express WNT5A. To determine if WNT5A and p53 may be promoting the survival of metastatic melanoma in an aged microenvironment, we examined tumors from young and aged C57/BL6 mice generated using Yumm1.7 cells. We found that tumors in aged mice have a higher percentage of cells expressing p53 and increased WNT5A expression compared to tumors in young mice. Treatment of human melanoma cells with conditioned media from aged dermal fibroblasts decreases proliferation and increases the percent of slow cycling. Inhibition of p53 re-sensitizes human melanoma cells in conditioned media from aged fibroblasts to combination BRAFi/MEKi. These data suggest, it may be these slow cycling cells driven by WNT5A and p53, which are enriched in an aging microenvironment, that are driving resistance to targeted therapy in aged patients.

Citation Format: Marie R. Webster, Mitchell Fane, Amanpreet Kaur, Gretchen Alicea, Brett L. Ecker, Abibatou Ndoye, Curtis Kugel, Subhasree Basu, Alexander Valiga, Jessica L. Appleton, Maureen E. Murphy, Ashani Weeraratna. Wnt-er is coming: WNT5A promotes a slow cycling phenotype via p53 in conditions of stress [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 993.
Abstract 994: Cancer cells induce a protumorigenic senescent phenotype in fibroblasts through MMP1 but not autophagy in large cell carcinoma of the lung
Authors: Alcaraz Jordi , Gabasa Marta , Ikemori Rafael , Reguart Noemí , Radisky Evette , Radisky Derek
Published: August 2018

Large cell carcinoma (LCC) is among the most aggressive histologic subtypes of non-small cell lung cancer, but the mechanisms underlying such aggressive nature remain unknown. We recently showed that fibroblasts from LCC patients exhibit premature senescence in vitro, and that co-culturing LCC cells (but not cancer cells from other lung cancer subtypes) with normal fibroblasts in transwells is sufficient to induce senescence in the latter in an oxidative stress-dependent manner, supporting that fibroblast senescence is induced by a secreted factor(s) from LCC cells. Remarkably, we also found that senescent fibroblasts secrete factors that stimulate the growth and invasion of LCC cells beyond the stimulation elicited by nonsenescent fibroblasts, revealing that fibroblast senescence may contribute to the aggressive nature of LCC. Whole-genome transcriptional profiling of a panel of lung cancer cell lines identified MMP1 among the genes with larger expression in LCC compared to other lung cancer subtypes. Since MMPs can induce oxidative stress, we examined whether the excessive MMP1 expression in LCC cells was involved in the induction of fibroblast senescence in co-cultures. Knocking down MMP1 in LCC cells was sufficient to abrogate fibroblast senescence in co-cultures as well as the growth and invasion enhancement elicited by the conditioned medium of fibroblasts in LCC cells. In contrast, autophagy, which has been previously associated with fibroblast senescence in breast cancer, was not upregulated in fibroblasts upon co-culture with LCC cells. These results support that the selective aberrant expression of MMP1 in LCC cells plays a major role in their ability to induce a protumorigenic senescent phenotype in adjacent fibroblasts through a mechanism that is independent of autophagy. Moreover, our observations identify MMP1 as a potential therapeutic target against the aberrant cancer cell-fibroblast crosstalk in LCC.

Citation Format: Jordi Alcaraz, Marta Gabasa, Rafael Ikemori, Noemí Reguart, Evette Radisky, Derek Radisky. Cancer cells induce a protumorigenic senescent phenotype in fibroblasts through MMP1 but not autophagy in large cell carcinoma of the lung [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 994.
Abstract CT017: Combined immunotherapy encompassing intratumoral poly-ICLC, dendritic-cell vaccination and radiotherapy in advanced cancer patients
Authors: Rodriguez-Ruiz Maria E. , Perez-Gracia Jose L. , Rodriguez Inmaculada , Alfaro Carlos , Gil-Bazo Ignacio , Gurpide Alfonso , Salazar Andres , Melero Ignacio
Published: August 2018

BACKGROUND: Combination immunotherapy has the potential to achieve additive or synergistic effects. Combined local injections of dsRNA analogues (mimicking viral RNA) and repeated vaccinations with tumor-lysate loaded dendritic cells shows efficacy against colon cancer mouse models. In the context of immunotherapy, radiotherapy can exert beneficial abscopal effects on distant non-irradiated lesions.

PATIENTS AND METHODS: In this pilot phase I study, 15 advanced cancer patients received two 4-week cycles of four intradermal daily doses of monocyte-derived dendritic cells preloaded with autologous tumor lysate and matured for 24h with poly-ICLC (Hiltonol), TNF-α and IFN-α. On days +8 and +10 of each cycle, patients received intratumoral image-guided 0.25 mg injections of the dsRNA-analogue Hiltonol. Cyclophosphamide 600 mg/m2 was administered one week before each cycle. Six patients received stereotactic ablative radiotherapy (SABR) on selected tumor lesions, including those injected with Hiltonol. Expression of 25 immune-relevant genes was sequentially monitored by RT-PCR on circulating PBMCs and serum concentrations of a cytokine panel were sequentially determined before and during treatment.

RESULTS: Combined treatment was feasible, safe and well tolerated, without grade 3-4 adverse events. One heavily pretreated castration-resistant prostate cancer patient experienced a remarkable mixed abscopal response to SABR and combined treatment. No objective responses were observed, while nine patients (Disease control rate=71%) presented stable disease (five in the six-patient radiotherapy cohort). Intratumoral Hiltonol increased IFN-β and IFN-α mRNA in circulating PBMC. Dendritic-cell vaccination increased serum IL-12 and IL-1β concentrations, especially in patients presenting stable disease.

CONCLUSIONS: This radio-immunotherapy combination strategy, aimed at resembling viral infection in tumor tissue in combination with a dendritic-cell vaccine and SABR, is safe and provides evidence of immune-associated activity and signs of preliminary clinical efficacy.

Citation Format: Maria E. Rodriguez-Ruiz, Jose L. Perez-Gracia, Inmaculada Rodriguez, Carlos Alfaro, Ignacio Gil-Bazo, Alfonso Gurpide, Andres Salazar, Ignacio Melero. Combined immunotherapy encompassing intratumoral poly-ICLC, dendritic-cell vaccination and radiotherapy in advanced cancer patients [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 CT017.
Abstract CT039: Cyclin E1 (CCNE1) expression associates with benefit from palbociclib in metastatic breast cancer (MBC) in the PALOMA3 trial
Authors: Turner Nicholas C. , Liu Yuan , Zhu Zhou , Loi Sherene , Colleoni Marco , Loibl Sibylle , DeMichele Angela , Harbeck Nadia , André Fabrice , Zhang Zhe , Giorgetti Carla , Bartlett Cynthia Huang , Cristofanilli Massimo
Published: August 2018

BACKGROUND: The CDK4/6 inhibitor palbociclib in combination with fulvestrant (F) improved progression-free survival (PFS) vs F alone in previously-treated MBC. Prior pre-clinical research, and the NeoPalAna window study, identified high CCNE1 expression as a potential palbociclib resistance marker. We conducted large panel gene expression analysis of baseline tumor tissue to identify biomarkers (BMs) that predicted the relative benefit of palbociclib.

METHODS: The PALOMA3 trial randomized 521 patients (pts) with endocrine-pretreated MBC to receive palbociclib + F or placebo (PBO) + F. All pts, except bone only or early relapse, provided FFPE tissue taken from recurrent disease. EdgeSeq Oncology BM Panel (HTG Molecular Diagnostics) was used for mRNA profiling, assessing 2534 cancer related genes. Primary objective was to evaluate the association of cell cycle pathway with palbociclib + F vs F alone treatment effect by using gene expression as a continuous variable or dichotomization by median level with Cox regression analysis.

RESULTS: 302 pts had tumor tissue analyzed (194/347 [56%] palbociclib + F; 108/174 [62%] PBO+F). The BM and overall populations had similar treatment effect. Benefit from palbociclib was greater in patients with low tumor CCNE1 expression (median PFS: palbociclib + F 14.1 mo vs PBO+F 4.8 mo, HR 0.32) than high tumor CCNE1 expression (palbociclib + F 7.6 mo vs PBO+F 4.0 mo; HR 0.85) (interaction p=0.0024). Similar results were observed with CCNE1 as a continuous variable (interaction p=0.0008). Expression levels of CDK4, CDK6, cyclin D1 and RB1 did not associate with benefit from palbociclib, and both luminal A and B tumors derived benefit from palbociclib. In exploratory analysis, high E2F-regulon expression predicted for relative resistance to palbociclib.

CONCLUSION: Higher expression of CCNE1 was associated with relative resistance to palbociclib, although all biomarker groups derived benefit from treatment. This data supports CDK2 as the key bypass kinase of CDK4/6 inhibition, and potential to target CDK2 to subvert resistance. Sponsor: Pfizer

Citation Format: Nicholas C. Turner, Yuan Liu, Zhou Zhu, Sherene Loi, Marco Colleoni, Sibylle Loibl, Angela DeMichele, Nadia Harbeck, Fabrice André, Zhe Zhang, Carla Giorgetti, Cynthia Huang Bartlett, Massimo Cristofanilli. Cyclin E1 (CCNE1) expression associates with benefit from palbociclib in metastatic breast cancer (MBC) in the PALOMA3 trial [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 CT039.
Abstract CT084: HEPANOVA: A phase II trial of tumor treating fields concomitant with sorafenib for advanced hepatocellular carcinoma
Authors: Grosu Anca-Ligia , Strouthos Josif , Brunner Thomas , Weinberg Uri
Published: August 2018

Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of glioblastoma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of hepatocellular carcinoma (HCC), leading to a significant increase in cell death. The Phase 2 HEPANOVA study is the first trial testing TTFields in HCC patients, and is designed to test the safety and efficacy of adding TTFields to sorafenib in advanced HCC.

Trial Design: Patients (N=25) with unresectable HCC who are not amenable to any local treatment will be enrolled in this prospective, single-arm study. The study enrolls patients with ECOG score of 0-2 and Barcelona clinic liver cancer (BCLC) stage 0-C. Patients must have a measurable disease per RECIST Criteria. Having implanted electronic devices in the torso is exclusionary. Sorafenib will be administered at standard dose (400 mg daily). TTFields (150kHz) will be deilvered for 18 hours/day until local disease progression per RECIST Criteria. Clinical follow up will be performed q4w, and a CT/MRI scan q12w. Following disease progression in the liver, patients will discontinue TTFields and be followed monthly for survival. Overall response rate will be the primary endpoint and in-field control rate, progression-free survival rate at 12 month (PFS12), OS rate at 1 year and toxicity will all be secondary endpoints. Sample size was calculated using an Exact test for proportions considering the weighted average of ORR of patients who had either complete or partial response per RECIST criteria in historical studies with sorafenib is 4.5%. A sample size of 25 patients was required to achieve a power of approximately 80% at a one-sided alpha level of 0.05 using a single sample Exact test for proportions.

Citation Format: Anca-Ligia Grosu, Josif Strouthos, Thomas Brunner, Uri Weinberg. HEPANOVA: A phase II trial of tumor treating fields concomitant with sorafenib for advanced hepatocellular carcinoma [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 CT084.
Abstract CT108: Tumor treating fields (TTFields) in combination with Lomustine (CCNU) in the EF-14 phase III clinical study: A safety analysis
Authors: Kinzel Adrian , Lavy-Shahaf Gitit , Kirson Eilon D
Published: August 2018

Introduction:

TTFields are low intensity (1-3V/cm), intermediate frequency (100-300 KHz) alternating electrical fields for the treatment of solid tumors. In the EF-14 phase 3 study, TTFields showed a significant overall and progression-free survival benefit for patients with newly diagnosed glioblastoma (GBM), in combination with Temozolomide (TMZ) (OS from randomization 20.9 vs. 16.0 months, p-value<0.001). The OS and PFS benefit of TTFields was seen in all patient subgroups, and was independent of MGMT promotor methylation-status, age, performance status and gender. TTFields were not associated with additional systemic toxicity. At recurrence, patients were allowed to continue TTFields with second line therapies. Here, we analyzed the safety data of TTFields + lomustine (CCNU) to evaluate the safety and feasibility of this combination.

Methods:

Patients in the EF-14 trial received TTFields until second progression, or for 24 months. Change in chemotherapy regimen was allowed in both groups after tumor progression. We compared the patients who received lomustine as second-line chemotherapy in combination with TTFields (n=134) to the patients who received lomustine as monotherapy after first progression (n=39). We compared baseline characteristics and the adverse event profile between the two groups.

Results:

Baseline characteristics were well balanced between both groups except for less female patients in the lomustine only group (7.7% vs. 22.4%). Median age in the TTFields/lomustine group was 55.5 years (29-83) compared to 50.0 years (19-71) for lomustine alone. The addition of TTFields to lomustine therapy was not associated with any significant increase in rates of systemic adverse events compared to lomustine therapy alone (number of patients with > 1 SAE 30 % vs. 31 %) and the distribution, severity and overall incidence of adverse events were not statistically different in patients in the two treatment groups.

Discussion:

The data show that the combination of TTFields and lomustine is a safe and feasible combination. This analysis emphasizes again the strong safety profile of TTFields and the high potential of combining TTFields with other therapy modalities. This data is especially important in light of the recently presented promising data from a small randomized trial that tested the combination of lomustine + TMZ in newly diagnosed (MGMT promotor-methylated only) GBM patients.

Citation Format: Adrian Kinzel, Gitit Lavy-Shahaf, Eilon D Kirson. Tumor treating fields (TTFields) in combination with Lomustine (CCNU) in the EF-14 phase III clinical study: A safety analysis [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 CT108.
Abstract CT157: PANOVA-3: A phase III study of TTFields with nab-paclitaxel and gemcitabine for front-line treatment of locally-advanced pancreatic adenocarcinoma (LAPC)
Authors: Weinberg Uri , Farber Ori , Giladi Moshe , Bomzon Zeev , Lavy-Shahaf Gitit , Kirson Eilon D.
Published: August 2018

Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of patients with glioblastoma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of pancreatic cancer. The Phase 2 PANOVA study was the first trial testing TTFields in pancreatic cancer patients, and demonstrated the safety of TTFields when combined with nab-paclitaxel and gemcitabine in both metastatic and LAPC. The Phase 3 PANOVA-3 trial (NCT03377491) is designed to test the efficacy of adding TTFields to nab-paclitaxel and gemcitabine combination in LAPC.

Trial Design: Patients (N=556) with unresectable, LAPC (per NCCN guidelines) will be enrolled in this prospective, randomized trial. Patients should have an ECOG score of 0-2 and no prior progression or treatment. Patients will be stratified based on their performance status and geographical region, and will be randomized 1:1 to TTFields plus nab-paclitaxel and gemcitabine or to nab-paclitaxel and gemcitabine alone. Chemotherapy will be administered at standard dose of nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2 once weekly). TTFields (150kHz) will be deilvered at least 18 hours/day until local disease progression per RECIST Criteria V1.1. Follow up will be performed q8w, including a CT scan of the chest and abdomen. Following local disease progression, patients will be followed monthly for survival. Overall survival will be the primary endpoint and progression-free survival, objective response rate, rate of resectability, quality of life and toxicity will all be secondary endpoints. Sample size was calculated using a log-rank test comparing time to event in patients treated with TTFields plus chemotherapy with control patients on chemotherapy alone. PANOVA-3 is designed to detect a hazard ratio 0.75 in overall survival. Type I error is set to 0.05 (two-sided) and power to 80%.

Citation Format: Uri Weinberg, Ori Farber, Moshe Giladi, Zeev Bomzon, Gitit Lavy-Shahaf, Eilon D. Kirson. PANOVA-3: A phase III study of TTFields with nab-paclitaxel and gemcitabine for front-line treatment of locally-advanced pancreatic adenocarcinoma (LAPC) [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 CT157.
Abstract LB-011: Novel nano-formulation of paclitaxel for pancreatic cancer therapy
Authors: Hafeez Bilal B. , Massey Andrew E. , Kashyap Vivek K. , Sikander Mohammad , Shetty Advit , Chaib Mehdi , Mandil Hassan , Yallapu Mohan , Jaggi Meena , Chauhan Subhash C.
Published: August 2018

Pancreatic cancer (PanCa) is one of the leading causes of cancer-related mortality in the United States due to very limited therapeutic options. Thus, there is an urgent need to develop novel therapeutic strategies for the management of this disease. Paclitaxel (PTX), a natural product derived from the Pacific Yew tree, is an agent typically used in combination therapy for PanCa. Currently, PTX nanoparticles (Abraxane®) along with gemcitabine are in use for the treatment of advanced PanCa. Herein, we have generated and characterized a novel nano-formulation of PTX comprised of PLGA core, stabilized with polyvinyl alcohol (PVA) and coated with poly-L-lysine (PLL). Dynamic light scattering (DLS) characterization indicated that the average particle size of this formulation was approximately 160 nm, and exhibited Zeta potentials of ~ -6.02 mV in 10% serum, along with an outstanding PL loading efficiency. We also evaluated the uptake mechanism of PPNPs in PanCa cells using different endocytosis inhibitors (Genistein, amiloride, nocodazole, chlorpromazine, and methyl beta cyclodextrin). Our results demonstrated that PPNPs were taken up mainly by lipid raft mediated endocytosis pathway in an energy-dependent manner. Next, we evaluated its therapeutic efficacy and underlying molecular mechanisms in human PanCa cells (HPAF-II, Panc1, and MiaPaCa-2) by performing various in vitro experiments. We first performed MTS and colony formation assays to determine the effects of free PTX and PPNPs on growth of PanCa cells. In this experiment, cells were treated with various concentrations of free PTX or abraxane, or PPNPs (2.5-160 nM) for 48 hrs. As a result, the PPNPs formulation showed more therapeutic effect over free abraxane as determined by decrease in cell proliferation and enhanced apoptosis induction in PanCa cells. PPNPs also showed a significant (P<0.01) inhibition in colony formation compared to free PTX. Moreover, PPNPs showed a superior inhibition of the invasive and migratory potential of HPAF-II and Panc1 as determined by commercially available kits (Invitrogen). PPNPs more effectively inhibited expression of GLI-1 and SHH as determined by qPCR and Western blot analysis. In conclusion, our findings suggest that PPNPs formulation has more anti-cancer potential than free PTX/Abraxane against PanCa and could be a novel therapeutic modality for the treatment of PanCa.

Citation Format: Bilal B. Hafeez, Andrew E. Massey, Vivek K. Kashyap, Mohammad Sikander, Advit Shetty, Mehdi Chaib, Hassan Mandil, Mohan Yallapu, Meena Jaggi, Subhash C. Chauhan. Novel nano-formulation of paclitaxel for pancreatic cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-011.
Abstract LB-042: Successful tumor formation following xenotransplantation of primary human ovarian cancer cells into severe combined immunodeficient (SCID) pigs
Authors: Boettcher Adeline N. , Kiupel Matti , Adur Malavika , Cocco Emiliano , Santin Alessandro , Charley Sara , Risinger John , Tuggle Christopher , Shapiro Erik
Published: August 2018

Ovarian cancer (OvCa) is the most lethal gynecologic malignancy, with 2/3 of patients having late-stage disease (stages II-IV) at diagnosis. Preclinical animal models for cancer research have primarily been restricted to rodents, but many preclinical cancer drug trials that succeed in mice fail in humans, potentially due to vast differences in physiology and size. Therefore, we sought to determine if pigs, which are more similar to humans in terms of anatomy and physiology, would be a viable preclinical animal model for OvCa. Our group has pioneered the development of severe combined immunodeficiency (SCID) pigs for biomedical research, a key technological advancement for xenotransplantation of human ovarian cancer cells to form tumors. In this study, we injected human OSPC-ARK-1 cells, a chemotherapy-resistant primary ovarian serous papillary carcinoma cell line, into the neck muscle and ear tissue of four SCID and two non-SCID pigs. Tumors developed in the ears of three SCID pigs, while two SCID pigs developed tumors in neck tissue, all of which were confirmed at pathology as true neoplasms. Non-SCID animals did not develop tumors in any location. Confirmation that OSPC-ARK1 cells can form tumors in SCID pigs substantiates further development of orthotopic models of OvCa in pigs for researching improved OvCa therapeutic and diagnostic methods.

Citation Format: Adeline N. Boettcher, Matti Kiupel, Malavika Adur, Emiliano Cocco, Alessandro Santin, Sara Charley, John Risinger, Christopher Tuggle, Erik Shapiro. Successful tumor formation following xenotransplantation of primary human ovarian cancer cells into severe combined immunodeficient (SCID) pigs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-042.
Abstract LB-047: Novel anti-psychotic drug for pancreatic cancer treatment
Authors: Ramachandran Sharavan , Srivastava Sanjay K.
Published: August 2018

Pancreatic cancer is one of the most deadly malignancy with a five-year survival rate of 7%. Despite advances in cancer treatment, this disease is still incurable and the treatment outcomes are limited. Few studies have shown that neuroleptic drugs exert better anti-proliferative effects in pancreatic cancer cells when compared to conventional chemotherapeutic agents gemcitabine and oxaliplatin. In the current study, we evaluated the anti-cancer effects of pimavanserin, an anti-psychotic drug used for the treatment of Parkinson's disease psychosis. Pimavanserin significantly suppressed the proliferation of AsPC1, BxPC3, PANC1, MIAPaCa2 and PO2 pancreatic cancer cells with the IC50 between 3 - 9µM at 24, 48 and 72 hours. Pimavanserin treatment induced 2-5 fold apoptosis in pancreatic cancer cells. Notably, no significant cell death was observed in normal human pancreatic ductal epithelial (HPDE-6) cells by pimavanserin treatment. Furthermore, pimavanserin treatment inhibits the expression of key oncogenic proteins and cancer stem cell markers such as pAkt(S473), pSTAT3(Y705), β-catenin, GLI-1, GLI-2, c-Myc, Oct-4, SOX-2, NANOG and CD44. We further evaluated the efficacy of pimavanserin in two different in vivo tumor models. Oral administration of 10mg/kg pimavanserin suppressed 50% of sub-cutaneously implanted BxPC3 tumors in athymic nude mice. In another setting, 10mg/kg pimavanserin by oral gavage inhibited the growth of orthotopically implanted PANC1 pancreatic tumors by 75%. Moreover, chronic administration of pimavanserin did not show any general signs of toxicity and no apparent changes were observed in the behavioral activity of mice. Further mechanistic studies are in progress. Since pimavanserin is already available in the clinic with established safety profile, our results will accelerate its clinical development for treatment of patients with pancreatic cancer. Our study is the first to demonstrate the anti-cancer effects of pimavanserin.

Citation Format: Sharavan Ramachandran, Sanjay K. Srivastava. Novel anti-psychotic drug for pancreatic cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-047.
Abstract LB-056: Novel molecular mechanism underlying cancer drug resistance: Involvement of p58IPKchaperone pathway
Authors: Athar Mohammad , Srivastava Ritesh
Published: August 2018

Rhabdomyosarcoma (RMS) is an aggressive and highly malignant form of pediatric cancer that develops from skeletal muscle cells. A third of these cancers become drug resistant, metastatic and fatal. Current therapeutic approaches have not resulted in significant improvement in outcome for patients with recurrent and/or metastatic disease. Here, employing two RMS-derived cell lines (RH30, a drug sensitive and RD, a drug resistant), we demonstrate a novel underlying molecular mechanism of drug resistance in these tumor subtypes. We show that in response to chemotherapeutics drugs [actinomysin D, torisol, etoposide and arsenic trioxide (ATO)], endoplasmic reticulum (ER) stress associated unfolded protein response (UPR) signaling pathway could be induced in RH30 cell only, while drug resistance RD cells largely lack this ability. The mechanism underlying UPR induction involves activation of multifunctional molecular chaperone P58IPK that besides regulating protein homeostasis is an inhibitor of the interferon-induced double-stranded RNA-activated protein kinase (PKR). We observed that the expression of p58IPK is high in drug resistance RD cells as compared to drug sensitive RH30 cells. To confirm its role in drug resistance, we ablated or overexpressed p58IPK respectively in drug resistant RD and drug sensitive RH30 cells. The p58IPK depleted RD cells became sensitive to chemotherapeutic agents while overexpressing p58IPK RH30 cells manifested drug resistance. To further demonstrate the known functional consequences of manipulation in the expression of p58IPK we found that P58IPK over-expression in RH30 cells inhibited eIF2α phosphorylation and diminished apoptosis by downregulating ATF4/CHOP/Cleaved caspase-3, while silencing of p58IPK in RD cells enhanced eIF2α phosphorylation and increased ATF4/CHOP/Cleaved caspase-3-dependent apoptosis in response to chemotherapeutic drug treatment. The underlying mechanism by which P58IPK alters drug sensitivity in RMS cells involves its chaperone function by its binding to drug transporters ABCB-1 and ABCC-1. At baseline, in RD cells with high p58IPK manifest significantly higher dye efflux as compared to RH30 with low p58IPK. This baseline drug exclusion profile correlated with the ATPase activity of these ABC transporters. However, ablation or overexpression of p58IPK respectively, in RH30/RD cells reversed their drug resistance phenotype. Thus, we have identified a novel drug resistance mechanism in RMS. These results may have translational implications in overcoming drug-resistance in deadly neoplasm. These studies are in progress in our laboratory.

Citation Format: Mohammad Athar, Ritesh Srivastava. Novel molecular mechanism underlying cancer drug resistance: Involvement of p58IPKchaperone pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-056.
Abstract LB-066: A high-throughput screen of an annotated small molecule library identifies substrates of P-glycoprotein
Authors: Lee Tobie D. , Lee Olivia W. , Brimacombe Kyle R. , Shen Min , Chen Lu , Guha Rajarshi , Tebase Bethelihem , Robey Robert W. , Ambudkar Suresh V. , Gottesman Michael M. , Hall Matthew D.
Published: August 2018

A major difficulty in treating cancer is the development of cellular resistance to chemotherapeutics, a phenomenon known as multidrug resistance (MDR). MDR is primarily conferred by an upregulation of ATP-binding cassette (ABC) transporters, most notably P-glycoprotein (P-gp, MDR1, ABCB1), which are responsible for the active transport of drugs out of the cells thereby minimizing drug-target interactions. While numerous strategies to overcome transporter-mediated MDR have been explored, none have proved successful. An alternative approach is to exploit resistance by identifying drugs that target MDR cells over the nonresistant parental cells from which they were selected. As such, the development of MDR1-selective agents represents a novel and relatively unexplored strategy for resolving multidrug resistance. To identify such agents, we developed a series of robust, high-throughput assays to examine differential toxicity between drug-naïve cancer cell lines and their drug-selected, multidrug-resistant sublines. We performed high-throughput screens against several libraries of annotated compounds including the NCATS Pharmaceutical Collection (NPC), a comprehensive collection of all clinically approved drugs - to identify P-gp substrates, and classes of small molecules that exhibit selective toxicity against MDR tumor lines. Further mechanistic evaluation of these compounds has provided valuable insight into targets or pathways that appear to have been rendered more sensitive to inhibition in the course of multidrug resistance development.

Citation Format: Tobie D. Lee, Olivia W. Lee, Kyle R. Brimacombe, Min Shen, Lu Chen, Rajarshi Guha, Bethelihem Tebase, Robert W. Robey, Suresh V. Ambudkar, Michael M. Gottesman, Matthew D. Hall. A high-throughput screen of an annotated small molecule library identifies substrates of P-glycoprotein [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-066.
Abstract LB-189: Novel bone morphogenetic protein receptor inhibitor JL5 suppresses tumor cell survival signaling and induces regression of human lung cancer
Authors: Newman Jenna H. , NeMoyer Rachel E. , Augeri David , Malhotra Jyoti , Langenfeld Elaine , Chesson Charles B. , Lee Micheal J. , Tarabichi Saeed , Jhawar Sachin R. , Bommareddy Praveen K. , Marshall Sh'rae , Sadimin Evita T. , Kerrigan John E. , Goedken Michael , Minerowicz Christine , Jabbour Salma K. , Li Shengguo , Dobias Natalie , Carayannopolous Mary O. , Zloza Andrew , Langenfeld John
Published: August 2018

Purpose: Studies have shown that bone morphogenetic protein (BMP) signaling is aberrantly expressed in lung and other carcinoma leading to pro-oncogenic effects on tumor growth. The BMP receptor inhibitor DMH2 induces death of lung cancer cells through the downregulation of anti-apoptotic proteins XIAP, TAK1, and Id1-Id3. Since DMH2 does not downregulate BMP signaling in vivo because of metabolic instability and poor pharmacokinetics better BMP inhibitors are needed.

Experimental Design: Here, we identified a site of metabolic instability of DMH2 and designed a novel BMP receptor inhibitor, JL5. We examined the effects of JL5 to downregulate BMP signaling and induce cell death of lung cancer cells in vitro and in vivo. We also queried the The Cancer Genome Atlas (TCGA) to assess if genetic alterations in lung cancer would affect drug targetability of the BMP receptors.

Results: We show that JL5 has improved pharmacokinetic profile compared to DMH2. JL5 suppresses BMP signaling in lung cancer cells in vitro and in tumor xenografts. Moreover, we demonstrate JL5-induced tumor cell death and tumor regression in xenograft mouse models without immune cells and humanized with adoptively transferred human immune cells. In humanized mice, JL5 additionally induces the infiltration of immune cells within the tumor microenvironment. The TCBA database analysis suggests that genetic alterations in the BMP signaling cascade will not limit targeting with small molecule inhibitors.

Conclusion: Our studies show that the BMP signaling pathway is targetable and BMP receptor inhibitors should be developed as a therapeutic to treat lung and other cancer patients.

Citation Format: Jenna H. Newman, Rachel E. NeMoyer, David Augeri, Jyoti Malhotra, Elaine Langenfeld, Charles B. Chesson, Micheal J. Lee, Saeed Tarabichi, Sachin R. Jhawar, Praveen K. Bommareddy, Sh'rae Marshall, Evita T. Sadimin, John E. Kerrigan, Michael Goedken, Christine Minerowicz, Salma K. Jabbour, Shengguo Li, Natalie Dobias, Mary O. Carayannopolous, Andrew Zloza, John Langenfeld. Novel bone morphogenetic protein receptor inhibitor JL5 suppresses tumor cell survival signaling and induces regression of human lung 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 LB-189.
Abstract LB-197: Transposon mutagenesis and CRISPR/Cas9 screening reveal pathways driving peripheral nerve sheath tumor development and maintenance
Authors: Reyes German L. Velez , Koes Nicholas , Kaufmann Gabriel , Ryu Esther , Largaespada David A.
Published: August 2018

Malignant Peripheral Nerve Sheath tumors(MPNSTs) are highly aggressive soft tissue sarcomas derived Schwann cell tumors. Half of these tumors occur sporadically, while the rest occur in the context of Neurofibromatosis Type 1 Syndrome (NF1) developing from pre-existing plexiform neurofibromas. NF1 is characterized by loss-of-function mutations in the gene encoding neurofibromin, a negative regulator of the oncogenic Ras pathway. To better understand genetic factors that give rise to MPNSTs, we performed a Sleeping Beauty (SB) transposon screen in mice. The results implicated Wnt/β-catenin, PI3K-AKT-mTOR, growth factor receptor signaling, and other pathways. It is our goal to understand the role of these pathways in human Schwann cell transformation, tumorigenesis, and tumor maintenance. We next sought to validate SB screen gene hits in a human cellular model using CRISPR/Cas9 technology as a tool to induce loss-of-function mutations in tumor suppressor gene (TSG) and oncogene candidates. A total 103 genes were independently targeted with multiple guideRNAs in immortalized human Schwann and MPNST cell lines and effects on transformation assessed. Transformation was assessed by anchorage-independent colony formation in soft agar, transwell migration, and tumor formation in NRG mice. In these assays, more than 30 genes scored as TSG candidates. Our results revealed a role for the Wnt/β-catenin, Hippo/Yap, PI3K-AKT-mTOR, Rho, and growth factor receptor signaling pathways in human neurofibroma and MPNST development and maintenance. These are generating hypothesis driven pre-clinical treatment studies we're pursuing now.

Citation Format: German L. Velez Reyes, Nicholas Koes, Gabriel Kaufmann, Esther Ryu, David A. Largaespada. Transposon mutagenesis and CRISPR/Cas9 screening reveal pathways driving peripheral nerve sheath tumor development and maintenance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-197.
Abstract LB-205: hnRNPM-IRES-mediated translation promotes colon cancer tumorigenesis
Authors: Chen Tsung-Ming , Lai Ming-Chih , Li Yi-Han , Tsai Shaw-Jenq , Sun H. Sunny
Published: August 2018

Internal Ribosome Entry Site (IRES)-mediated translation is known to play a vital role for cell survival under stress conditions, yet the crucial players involved in this translational reprogramming remain largely unidentified. This study aims to elucidate the missing piece of pathway underlying the hypoxia-induced, IRES-mediated translational activation in the cancer genome. By using the proteomic profiling approach, we discovered hnRNPM as a new IRES interacting factor to activate translation in colon cancer cells. Mechanistic studies revealed that hypoxia increases hnRNPM binding onto mRNA and promotes translation of a set of critical genes relating to cell survival and metabolism. Transcriptomics and translatomics analyses discovered a unique set of hnRNPM-target mRNAs with increased ribosome occupancy under hypoxia to provoke tumorigenesis. Clinical specimen and mouse carcinogenesis model showed that hnRNPM overexpression accompanies colorectal cancer development and positively correlated with hypoxia biomarker. Collectively, these data highlight the novel role of hnRNPM-IRES-mediated translation in transforming hypoxia-induced proteome toward malignancy and demonstrate significant implications for targeting hnRNPM in future anticancer therapy.

Citation Format: Tsung-Ming Chen, Ming-Chih Lai, Yi-Han Li, Shaw-Jenq Tsai, H. Sunny Sun. hnRNPM-IRES-mediated translation promotes colon cancer 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 LB-205.
Abstract LB-206: Inhibition of MYC by the SMARCB1 tumor suppressor
Authors: Weissmiller April M. , Wang Jing , Lorey Shelly L. , Howard Gregory C. , Martinez Ernest , Liu Qi , Tansey William P.
Published: August 2018

The SMARCB1 tumor suppressor (SNF5) is a known interaction partner of the oncoprotein c-MYC (MYC), and thought to serve as a co-activator of its transcriptional properties. This role of SNF5, however, is at odds with the tumor suppressor function of SNF5, and with findings that loss of SNF5 is associated with activation of MYC target gene signatures. We have used biochemical, genetic, and genome-wide approaches to reexamine the relationship of SNF5 with MYC within the context of malignant rhabdoid tumor (MRT), an aggressive childhood cancer in which SNF5 is lost. We find that, consistent with activation of MYC target gene signatures in tumors that lack SNF5, MYC function is important for multiple aspects of MRT biology. Surprisingly, SNF5 is capable of inhibiting MYC binding to E boxes in vitro and globally within the context of chromatin. Using ATAC-seq, RNA-seq, and PRO-Seq, we demonstrate that regulation of MYC binding by SNF5 is independent of the role of SNF5 in chromatin remodeling, but instead is responsible for controlling RNA polymerase pause release at MYC-regulated genes. These findings inform a novel model of MRT tumorigenesis in which loss of SNF5 derepresses MYC function, raising the possibility that MYC contributes to disease progression in this malignancy.

Citation Format: April M. Weissmiller, Jing Wang, Shelly L. Lorey, Gregory C. Howard, Ernest Martinez, Qi Liu, William P. Tansey. Inhibition of MYC by the SMARCB1 tumor suppressor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-206.