bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 969A: The histone methyltransferase EZH2 is a novel target of anticancer therapy in endometrial cancer
Authors: OKI SHINYA , SONE KENBUN , ODA KATSUTOSHI , NISHIJIMA AKIRA , TAKEUCHI MAKOTO , AGAPITI CHUWA , ASADA KAYO , MAKII CHINAMI , KAWANA KEI , OSUGA YUTAKA , FUJII. TOMOYUKI
Published: July 2016

Besides genetic disorders, dysregulation of epigenetic machinery has been proved to play a crucial role in human carcinogenesis, and the histone methylation/demethylation process has been considered as one of key regulators for this event. However, the roles of these alterations in cancer progression have not been well characterized in endometrial cancer. The aim of this study is to elucidate that one of methyltransferases, enhancer of zeste homolog 2 (EZH2) is a novel target of anti-cancer therapy in endometrial cancer.

We demonstrate that EZH2 plays pivotal roles in human endometrial cancer. To confirm these roles, we performed the expression profile of EZH2 in 11 endometrial cancer cell lines and 50 clinical endometrial cancer specimens, under informed consent and approval of our ethics committee. In addition, we performed the functional analysis of

EZH2 using endometrial cancer cell lines. The expression Quantitative real-time PCR revealed that EZH2 is aberrantly overexpressed in endometrial cancer cell lines and clinical samples compared with immortalized endometrial cell line and normal endometrial tissues (P<0.05). The reduction of EZH2 expression by small interfering RNAS resulted in suppression of growth of cancer cells and caused apoptotic cell death in endometrial cancer cell lines.

Our results suggest that dysregulation of EZH2 plays an important role in the growth regulation of endometrial cancer cells, and further functional studies may affirm the importance of EZH2 as a promising therapeutic target for endometrial cancer.

Citation Format: SHINYA OKI, KENBUN SONE, KATSUTOSHI ODA, AKIRA NISHIJIMA, MAKOTO TAKEUCHI, CHUWA AGAPITI, KAYO ASADA, CHINAMI MAKII, KEI KAWANA, YUTAKA OSUGA, TOMOYUKI FUJII. The histone methyltransferase EZH2 is a novel target of anticancer therapy in endometrial 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 969A.
Abstract 988: A novel long non-coding RNA, TSA-LINC2, regulates cellular growth and is associated with poor prognosis in breast cancer
Authors: Pichler Martin , Cerk Stefanie , Stiegelbauer Verena , Schwarzenbacher Daniela , Ling Hui
Published: July 2016

Background: Long non-coding RNAs (LINCs) are an emerging class of molecules in cancer diagnosis and prognosis. The number of LINCs exceeds the number of protein-coding genes and their role in breast cancer is largely unknown.

Methods: In this study we used non-adherent growing tumor spheres (“mammospheres”) as a model system to identify tumor-sphere associated (TSA) gene expression patterns. We used microarrays to profile different breast cancer cell lines and selected the most up/down-regulated differentially expressed genes by RT-PCR. Clinical correlations including survival analysis of almost 900 breast cancer patients in two independent cohorts and experimental evaluation of the biological function were done.

Results: Among several TSA-genes, one novel not previously reported LINC, (that we termed TSA-LINC2) was significantly up-regulated in mammospheres (up to 50 fold, p<0.05). In patient samples, TSA-LINC2 was significantly up-regulated in cancer tissue compared to normal breast tissue, and high expression was associated with poor survival in different molecular breast cancer subtypes (p<0.05). Knock-down experiments of TSA-LINC2 in a panel of breast cancer cell lines led to significantly altered cellular growth, anchorage-independent growth and mammosphere formation in triple negative (p<0.05). Molecular profiling with gene expression arrays shows that TSA-LINC2 regulates cell cycle-associated genes.

Conclusion: This novel long non-coding RNAis involved in breast cancer progression and might be useful as a prognostic marker in breast cancer patients.

Citation Format: Martin Pichler, Stefanie Cerk, Verena Stiegelbauer, Daniela Schwarzenbacher, Hui Ling. A novel long non-coding RNA, TSA-LINC2, regulates cellular growth and is associated with poor prognosis 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 988.
Abstract 996: STAT3 modulates HOTAIR transcription to influence HNSCC growth in vitro and in vivo
Authors: Zhou Xuan
Published: July 2016

Background

Squamous cell carcinoma is the most common cancer type of head and neck (HNSCC) with poor prognosis. Signal transducer and activator of transcription 3 (STAT3) activation is involved in HNSCC carcinogenesis as a transcript factor. A new class of transcripts, long noncoding RNAs (lncRNAs), has been recently found to be pervasively transcribed in the genome. HOTAIR, lncRNA Hox transcript antisense intergenic RNA, has been characterized as a novel hall marker to predict poor prognosis in HNSCC. HOTAIR regulates downstream target gene transcription by recruiting polycomb repressive complex 2 (PRC2) to the cell nucleus and triggers triple methylation of H3K27.

Methods

RNA sequencing, qPCR and CHIP assay were used to determine HOTAIR is a down-stream gene of STAT3. MTT and western blot were employed to examine the regulatory mechanism between STAT3 and HOTAIR in HNSCC cancers in vitro. Additionally, a cell derived xenograft tumor model was used to further validate the anti tumor effect of targeting STAT3/HOTAIR axis in vivo.

Results

STAT3 depleted HNSCC cell showed decreased HOTAIR expression by qPCR assay. CHIP assay indicated STAT3 bind to the promoter region of HOTAIR encoding gene. Combined inhibition of STAT3 and HOTAIR significantly inhibited cell proliferation, sensitive to cisplatin in HNSCC. Up-regulating HOTAIR partially compensated anti-tumor effect of targeting STAT3 in HNSCC.

Conclusion

Our data suggested that HOTAIR overexpression is depended on constitutive STAT3 activation in HNSCC and targeting STAT3/HOTAIR axis showed significant therapeutic potential in vitro and in vivo.

Citation Format: Xuan Zhou. STAT3 modulates HOTAIR transcription to influence HNSCC growth in vitro and in vivo. [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 996.
Abstract 997: Hotair promotes glioma cell cycle through a b-catenin mediated mRNA network
Authors: Wang Qixue , Huang Kai , Ren Yu , Wang Yunfei , Zhou Bingcong , Tan Yanli , Fang Chuan , Li Jie , Kang Chunsheng
Published: July 2016

Background:

LncRNA hotair is an oncogene that involves in the progression of several cancers. Previously we and others have reported that hotair promotes glioblastoma progression by regulating cell cycle. However, further mechanism still needs to be explored. The wnt/b-catenin signaling pathway is a crucial factor in the development of many cancers. B-catenin is a nuclear transcription factor that regulates multiple genes involved in cell proliferation, survival and EMT that contribute to glioma development.

Methods:

Positive correlation genes of hotair were picked up from CGGA (Chinese Glioma Genome Atlas) database by bioinformatics analysis. Real Time PCR is used to test the mRNA expression levels in U87 cells and astrocytes. Western blot is emplored to determine PKM2 expression after knocking down hotair. Further more, and nude mouse glioma intracranial model is employed to examine in vivo impact of hotair on GBM.

Results:

Hotair is a cell cycle related lncRNA as previously reported. Bioinformatics analysis indicated that various genes play important roles on cell cycle are positively correlated with hotair. Theses genes might be the executors of hotair on cell cycle regulating. We constructed a top 18 hotair-related genes network by connectivity. To test the hypothesis, we knock down hotair expression in U87 cells, and found out that FOXM1, CCNA2, CEP55, CENEP, CCNB2, HMMR, NCAPG, NUSAP were down-regulated significantly. In addition, overexpression of hotair in astrocytes could upregulate the mRNA of those genes. To further explore the regulatory mechanism, we analyed the promoter of these hotair-regulated genes and found out b-catenin/TCF4 binding site on all of them. This indicated that hotair might upregulate cell cycle associated genes through b-catenin/TCF4 pathway. FH535 is an inhibitor of wnt/b-catenin. The mRNA expression of these genes could be suppressed by FH535 treatment, which confirms the promoter analysis. It is reported that PKM2 could promote b-catenin nuclear translocation. Interestingly, we found out that binding site of miR-330 exists on both of hotair and PKM2 mRNA. Knocking-down of hotair inhibited PKM2 mRNA and protein expression in U87, U87vIII, U251 and LN229 cells. Further more, hotair siRNA could inhibit glioma growth in vivo.

Conclusion:

Our data indicated that hotair promotes glioma cell cycle through a b-catenin mediated mRNA network, and hotair could be a a biomarker and therapeutic target in glioblastoma. Meanwhile, there are still a lot of work to be done.

Citation Format: Qixue Wang, Kai Huang, Yu Ren, Yunfei Wang, Bingcong Zhou, Yanli Tan, Chuan Fang, Jie Li, Chunsheng Kang. Hotair promotes glioma cell cycle through a b-catenin mediated mRNA network. [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 997.
Abstract CT016: Abexinostat (ABX) as a means to reverse pazopanib (PAZ) resistance: a phase I study in advanced solid tumor malignancies
Authors: Aggarwal Rahul , Thomas Scott , Grabowsky Jennifer , Harb Armand , Leng Jim , Reinert Anne , Mastroserio Ilaria , Truong Thach-Giao , Munster Pamela N.
Published: July 2016

Background: PAZ is a tyrosine kinase inhibitor of VEGFR, PDGFR, and c-KIT approved for use in renal cell carcinoma (RCC). ABX is a potent pan-HDAC inhibitor (HDACi). Pre-clinical models suggest that HDACi-mediated epigenetic modulation of VEGF expression prevents PAZ resistance and potentiates efficacy. We therefore designed a Phase I clinical trial combining ABX with PAZ in pts with advanced solid tumors with an expansion cohort in RCC.

Methods: The primary endpoint was the maximal tolerated dose (MTD) of PAZ plus ABX. Secondary endpoints included pharmacokinetics (PK) and efficacy. PAZ was dosed days 1-28 and ABX days 1-5, 8-12, and 15-19 of 28-day cycle (schedule A) with at a starting dose of 400 mg/day and 45 mg/m2 orally twice daily respectively. An alternate ABX dosing schedule days 1-4, 8-11, and 15-18 was investigated (schedule B) due to toxicity of Schedule A.

Results: 52 patients (pts) (RCC; N = 23) with advanced solid tumors were enrolled (N = 22 schedule A; N = 30 schedule B). There were six dose-limiting toxicities including fatigue (N = 2), thrombocytopenia (N = 2), and elevated AST/ALT (N = 2). The most common grade ? 3 related adverse events observed were fatigue (13%), thrombocytopenia (12%), and diarrhea (10%). The MTD was PAZ 800 mg/day + ABX 45 mg/m2 BID on schedule B. 8 evaluable pts (19%) (N = 6 RCC; 2 thyroid; median number of prior lines of therapy = 3) achieved partial tumor response (PR), with median duration of response of 9.2 months (1-33.2+). 7/9 (78%) of pts with prior disease progression on PAZ monotherapy had reduction in tumor burden on study. 15 out of 48 evaluable pts (31%) experienced stable disease or better for ? 6 months, and two previously PAZ-refractory pts with PRs remain on study for > 20 and 37 mos respectively. PK analyses did not reveal drug-drug interaction. Degree of histone acetylation and metabolomic profile are being evaluated.

Conclusion: The combination of PAZ + ABX was well tolerated and durable tumor control (> 3 yrs) was observed in RCC and thyroid cancer. Tumor regressions observed in majority of PAZ-refractory tumors preliminarily support the potential of ABX to reverse therapeutic resistance. A randomized phase 2 study with cross-over design is planned to further evaluate the combination of PAZ + HDACi.

Citation Format: Rahul Aggarwal, Scott Thomas, Jennifer Grabowsky, Armand Harb, Jim Leng, Anne Reinert, Ilaria Mastroserio, Thach-Giao Truong, Pamela N. Munster. Abexinostat (ABX) as a means to reverse pazopanib (PAZ) resistance: a phase I study in advanced solid tumor malignancies. [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 CT016.
Abstract CT077: PRECISION (Profiling Early Breast Cancer for Radiotherapy Omission): a phase II study of breast-conserving surgery without adjuvant radiotherapy for favorable-risk breast cancer
Authors: Braunstein Lior Z. , Taghian Alphonse G. , Harris Jay R.
Published: July 2016

Background: Radiation therapy (RT) following breast conserving surgery (BCS) is well-known to improve outcomes for patients with invasive breast cancer. However, RT poses an inconvenience to patients and confers a small, yet real, risk of long-term adverse effects. In addition, reports have suggested that not all patients stand to benefit equally from RT, with certain disease features portending an excellent prognosis regardless of the adjuvant treatment approach. Specifically, favorable luminal A cancers exhibit a 10-year locoregional recurrence (LRR) rate of 2% following BCS and RT, suggesting very low putative risk in the absence of RT. While luminal A breast cancers are the most favorable among subtypes, robustly distinguishing them from luminal B tumors is a challenge. This trial seeks to employ a molecular profiling approach to identify favorable-risk, early-stage breast cancer patients who may feasibly omit RT following BCS.

Methods: To identify a low-risk, luminal A cohort of breast cancer patients, we will employ well-characterized clinicopathologic parameters in addition to molecular profiling. Eligible patients will be 50-75 years of age and must have invasive breast cancer ?2 cm (T1), that is estrogen receptor positive, low- or intermediate-grade, without HER2 amplification, and with negative margins (no ink on tumor) following BCS. Following resection, tumor samples will undergo prediction analysis of microarray 50 (PAM50) profiling via the NanoString Prosigna assay to characterize intrinsic biologic subtype. Patients with tumors classified as luminal A (low-risk score) will be eligible for the omission of RT. The trial is a single-arm prospective cohort study designed to assess the viability of RT omission in this favorable population. The primary endpoint will be LRR at 5 years and a rate of <5% will be considered of interest. Projected accrual will be 345 patients to be enrolled over 4 years. Using this design, the study has 90% power to distinguish a 5-year LRR rate of 1% from 5% using a one-sample exponential test with one-sided type I error of 0.025. Secondary endpoints include 5- and 10-year recurrence rates of any type (local, regional and/or distant), disease-free survival, invasive-disease-free survival and overall survival, in addition to rates of salvage mastectomy and radiotherapy. (ClinicalTrials.gov: NCT02653755)

Citation Format: Lior Z. Braunstein, Alphonse G. Taghian, Jay R. Harris. PRECISION (Profiling Early Breast Cancer for Radiotherapy Omission): a phase II study of breast-conserving surgery without adjuvant radiotherapy for favorable-risk 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 CT077.
Abstract CT114: Phase Ib/II Study of RX-0201, a novel AKT-1 antisense, combined with everolimus to treat metastatic clear cell renal carcinoma - Phase Ib results
Authors: Tagawa Scott , Chatta Gurkamal S. , Pal Sumanta K. , Goel Sanjay , Mazhari Reza , Heaton Callie , Benaim Ely , Agarwal Neeraj
Published: July 2016

Background: RX-0201, a novel, oligonucleotide that binds native AKT-1 mRNA, prevents downstream phosphorylation to p-AKT. RX-0201, in combination with everolimus, additively inhibited Caki-1 cell growth in vitro and is in development for the treatment of metastatic clear cell renal carcinoma

Methods: The phase Ib/II proof of concept, multicenter, open label study is conducted in 2 phases. The phase Ib was a dose-escalation study of RX-0201 administered in combination with everolimus. RX-0201 was administered as a continuous intravenous infusion for 14 days followed by 7 days of rest; everolimus was administered at a starting dose of 10mg once daily. Subjects were enrolled at increasing doses of RX-0201 in a modified 3+3 design. Plasma concentrations were measured in phase Ib and noncompartmental pharmacokinetic parameters were calculated using WinNonlin, Version 6.4. The dose of RX-0201 identified in phase Ib is being studied further in phase II, which is the randomized, 2-arm study of RX-0201 in combination with everolimus versus everolimus alone.

Results: In the Phase Ib, seven males and 3 females, (median age 61 years) were treated with 125 mg/m⁁2/day (n = 3), 200 mg/m⁁2/day (n = 4), and 250 mg/m⁁2/day (n = 3) RX-0201 in combination with 10 mg everolimus. They received 1-3 lines of therapy prior to study entry (median = 1). The most common toxicities attributed to the combination were rash, mouth ulceration, weight loss, thrombocytopenia, facial edema, fatigue, and pruritus. No significant events were attributed to RX-0201 alone. Most events (81%) were mild or moderate in severity. Based on the tolerability, 250 mg/m⁁2/day RX-0201 dose was declared the recommended phase II dose. Three subjects in the phase Ib have experienced stable disease for 383, 191, and 122 days; a tumor burden reduction of 16 and 36% was seen in 2 subjects. RX-0201 PK demonstrated a dose proportional exposure.

Conclusions: RX-0201, in combination with everolimus, appears to be safe and well tolerated in patients with metastatic renal cancer at doses up to 250 mg/m⁁2/day. Randomized phase II of this trial is currently ongoing.

Citation Format: Scott Tagawa, Gurkamal S. Chatta, Sumanta K. Pal, Sanjay Goel, Reza Mazhari, Callie Heaton, Ely Benaim, Neeraj Agarwal. Phase Ib/II Study of RX-0201, a novel AKT-1 antisense, combined with everolimus to treat metastatic clear cell renal carcinoma - Phase Ib results. [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 CT114.
Abstract CT133: Association of programmed death-ligand 1 (PD-L1) and 2 (PD-L2) expression with nivolumab (NIVO) efficacy in advanced melanoma (MEL)
Authors: Rodig Scott J. , Gjini Evisa , Desai Kaushal , Jin Chelsea , Horak Christine , Ruisi Mary , Weber Jeffrey , Freeman Gordon J. , Hodi F. Stephen
Published: July 2016

Background: NIVO inhibits the interaction of the PD-1 receptor with its ligands, PD-L1 and PD-L2. While high tumor PD-L1 expression results in greater clinical benefit with NIVO, MEL patients (pts) with low-to-no PD-L1 expression also benefit from NIVO. This may be partially attributed to PD-L2. Here, we analyzed the association between PD-L1/PD-L2 expression and efficacy from a phase II study (CheckMate 064) evaluating NIVO followed by ipilimumab (IPI) vs IPI followed by NIVO in MEL.

Methods: Pts were randomized 1:1 to receive sequential treatment with NIVO (3 mg/kg IV Q2W x 6) then IPI (3 mg/kg IV Q3W x 4) (cohort A) or IPI then NIVO (cohort B). Pts were biopsied prior to treatment and at Wk 13; pts had only received one agent at Wk 13. PD-L1 and PD-L2 expression were assessed by immunohistochemistry on formalin-fixed, paraffin-embedded tumor samples with the Dako PD-L1 28-8 pharmDx assay and a novel PD-L2 assay (antibody clone 9E5). Dichotomization of the percent expression of PD-L1 and PD-L2 was optimized by ROC analyses.

Results: In pre-treatment samples, 32/97 (33%) pts had PD-L1 expression ?5% and 38/83 (46%) pts had PD-L2 expression ?70%. No consistent change from baseline in PD-L1 or PD-L2 was observed in either cohort with treatment. The frequency of pts with PD-L2 expression ?70% was higher among pts with PD-L1 ?5% vs PD-L1 <5%: 63% (19/30) vs 36% (17/47). In cohort A, there was a greater mean tumor burden reduction and higher response rates at Wk 13 among pts with high vs low PD-L2 expression, even in pts with low-to-no PD-L1 (Table). No association between PD-L2 and efficacy was observed in cohort B.

Conclusions: Similar to PD-L1, PD-L2 expression may enrich response to NIVO in MEL. PD-L2 expression may partially explain the efficacy of NIVO in pts with low-to-no PD-L1. However, NIVO is still active in pts with low-to-no expression of both ligands, suggesting other factors may explain the activity of NIVO. Further analysis is required to delineate these factors. ExpressionStatus, %NCheckMateCheckMate064064Cohort ACohort BPD-L1PD-L2Tumor response, n/N (%)Reduction in tumor burden, %Tumor response, n/N (%)Reduction in tumor burden, %≥5≥70197/13 (54)-26.62/6 (33)4.9≥5<70112/7 (29)-13.30/4 (0)49.8<5≥70174/10 (40)-28.40/7 (0)58.0<5<70304/18 (22)-2.80/12 (0)31.3

Citation Format: Scott J. Rodig, Evisa Gjini, Kaushal Desai, Chelsea Jin, Christine Horak, Mary Ruisi, Jeffrey Weber, Gordon J. Freeman, F. Stephen Hodi. Association of programmed death-ligand 1 (PD-L1) and 2 (PD-L2) expression with nivolumab (NIVO) efficacy in advanced melanoma (MEL). [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 CT133.
Abstract LB-015: XIAP induction by the MAPK-eIF4G1 pathway drives NFκB activation in inflammatory breast cancer growth and therapeutic resistance
Authors: Evans Myron K. , Geradts Joseph , Edwards Courtney , Price Arianna , Arora Arjun J. , Aldrich Amy J. , Ramirez Adrian , Robinson Timothy J. , Vermeulen Peter B. , van Laere Steven , Devi Gayathri R.
Published: July 2016

Inflammatory breast cancer (IBC) is the most lethal, distinct form of breast cancer, however, the basis for its aggressiveness and rapid acquisition of drug resistance is not fully understood. Using immunohistochemical analysis, we identified a strong correlation between high grade, high stage, and triple-negative status and elevated expression of the X-linked inhibitor of apoptosis protein (XIAP) in IBC. Molecular profiling of multiple IBC cell lines revealed that modulating XIAP expression can significantly alter the expression pattern of a 79-gene, characteristic IBC profile that was previously obtained from clinical samples. Using specific antagonists and RNAi, we determined that the mitogen activated protein kinase (MAPK) pathway and its interaction with the protein synthesis initiation factor eIF4G1, both of which are elevated in IBC, cooperate to drive XIAP induction and resistance to therapeutic apoptosis. Further, we found that XIAP expression directly correlates with activation of the transcription factor NFκB, a molecular component defining IBC. Mutational analysis revealed that the BIR1 domain of XIAP is essential for subsequent TAB1:IKKβ-dependent NFκB activation. After determining this association between XIAP and TAB1, we tested a peptide-mediated strategy used to block the BIR1:TAB1 interaction antagonized NFκB activity which led to decreased anchorage independent growth and reversed resistance to an EGFR tyrosine kinase inhibitor. Most significantly, orthotopic implantation of XIAP silenced IBC cells revealed the necessity of expression for IBC tumor growth, while overexpression of XIAP enhanced tumor growth. Our findings establish that XIAP augments the malignant properties in IBC by enhancing NFκB function, identify a druggable pathway with multiple targets, and provide feasibility for the development of novel therapeutics targeting the BIR1 domain of XIAP in IBC.

Grant Support: Supported by American Cancer Society, the Duke Cancer Institute as part of the P30 Cancer Center Support Grant NIH CA014236, the Duke Department of Surgery, and DOD grant W81XWH-13-1-0047.

Citation Format: Myron K. Evans, Joseph Geradts, Courtney Edwards, Arianna Price, Arjun J. Arora, Amy J. Aldrich, Adrian Ramirez, Timothy J. Robinson, Peter B. Vermeulen, Steven van Laere, Gayathri R. Devi. XIAP induction by the MAPK-eIF4G1 pathway drives NFκB activation in inflammatory breast cancer growth and therapeutic resistance. [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 LB-015.
Abstract LB-039: Genetic dissection of mechanisms underlying epidermal growth factor receptor-independent colorectal cancer development
Authors: Mantilla-Rojas Carolina , Yu Ming , Threadgill David
Published: July 2016

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the United States. Substantial effort has gone into understanding molecular mechanisms governing CRC progression with the goal of developing potent targeted therapies. Epidermal growth factor receptor (EGFR) was one of the first molecular targeted therapies. However clinical trials using EGFR inhibitors are not as efficient, suggesting an alternative and independent EGFR-CRC progression mechanism. In this study, we also evaluated the importance of ERBB3, a related EGF receptor, in EGFR-independent colorectal cancer progression. Using intestine-specific genetic ablation of Egfr in the ApcMin/+ (genetic) and axozymethane (carcinogenic) CRC mouse models, we show that 10% of colonic tumors arise independent of EGFR activity. Molecular analysis confirmed the lack of Egfr in these tumors and the formal proof for the existence of an EGFR-independent pathway. Tumors developing in absence of EGFR are larger in size than those developing under normal EGFR activity suggesting that EGFR independent tumors may have a faster growth rate. We also have evidence that ERBB3 may mediate compensatory pathways. Using intestinal specific ablation of Erbb3 (Erbb3f/f) we previously showed that the number of intestinal tumors in the ApcMin/+ model is greatly reduced. Importantly, polyps forming in absence of ERBB3 are significantly smaller than controls, suggesting that normal levels of ERBB3 signaling is essential for tumor growth in the ApcMin/+ model. More recently, we have generated a combinatorial model that conditionally inactivates both Erbb3 and Egfr in the intestinal epithelia. These models will provide powerful tools to genetically dissect molecular pathways contributing to CRC, and aid in identifying molecular biomarkers that can differentiate EGFR-independent from EGFR-dependent CRC. These studies may advance understanding of ERBB biology during colonic tumorigenesis and help design better therapies in combination with EGFR-targeted agents.

Citation Format: Carolina Mantilla-Rojas, Ming Yu, David Threadgill. Genetic dissection of mechanisms underlying epidermal growth factor receptor-independent colorectal cancer development. [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 LB-039.
Abstract LB-063: A high-resolution, quantitative proteomic map of human prostate cancer cells
Authors: Zhou Bo , Freeman Michael R. , Yang Wei
Published: July 2016

Prostate cancer is the second leading cause of cancer death in American men. Despite remarkable progress in the past decade, the molecular basis of prostate cancer development and progression remains incompletely understood. Owing to the rapid advancement of next generation sequencing technologies, whole-genome and -transcriptome sequencing have been increasingly applied to analyze prostate cancer. In comparison, whole-proteome sequencing of prostate cancer remains very challenging. Here, by applying three different endoproteinases (i.e., trypsin, Glu-C and Asp-N) and two-dimensional liquid chromatography-tandem mass spectrometry, we generated a high-resolution and quantitative proteomic map for DU145, a widely used human prostate cancer cell line. A total of 11,759 non-redundant protein groups were identified with a false discovery rate of 1%, corresponding to 10,561 genes. The absolute abundance of each identified protein was computed, ranging from 110 million to several copies (median = 35,700 copies). In addition, a recent RNA-Seq analysis of DU145 cells suggested that only 10,964 genes have FPKM values of ? 1, indicating that our proteomic profiling covers almost the entire proteome. Among the 10,561 identified genes, at least 904 (e.g., BRAF, BRCA1, EZH2, FGFR1, HNF1B, and STAT3) express two to eight different protein isoforms, some of which have not been characterized before. In addition, proteogenomic analysis identified over 40 aberrant proteins derived from alternative splicing and site mutation as well as translation from 5’UTR, long non-coding RNAs, and pseudogenes. In conclusion, we generated the first near-complete quantitative proteomic map for prostate cancer cells, which may guide the discovery of prostate cancer-specific protein biomarkers.

Citation Format: Bo Zhou, Michael R. Freeman, Wei Yang. A high-resolution, quantitative proteomic map of human prostate 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 LB-063.
Abstract LB-088: Heterodimeric IL-15 enhances tumor infiltration, persistence and effector functions of adoptively transferred tumor-specific T cells in the absence of lymphodepletion
Authors: Ng Sinnie , Bergamaschi Cristina , Nagy Bethany , Alicea Candido , Jensen Shawn M. , Fox Bernard A. , Felber Barbara K. , Pavlakis George N.
Published: July 2016

Adoptive cell transfer (ACT) is a promising immunotherapeutic approach for cancer. Lymphodepletion of the host is associated with favorable ACT outcomes but it may cause detrimental effects in humans. Lymphodepletion results in high level of homeostatic cytokines including Interleukin-15 (IL-15) that support survival and proliferation of the transferred lymphocytes. We tested the hypothesis that exogenous IL-15 enhances ACT in the absence of lymphodepletion. We have previously shown that bioactive IL-15 in vivo comprises a stable complex of the IL-15 chain with the IL-15 Receptor alpha chain, termed heterodimeric IL-15 (hetIL-15). We therefore evaluated the effects of the combination regimen ACT+hetIL-15 in absence of lymphodepletion by transferring melanoma-specific Pmel-1 T cells into B16 melanoma-bearing mice. hetIL-15 promoted infiltration and persistence of both adoptively transferred Pmel-1 cells and endogenous CD8+ T cells in the tumor. Following lymphodepletion by irradiation, Pmel-1 cells also localized to tumor sites efficiently, but their persistence was severely reduced in comparison to mice treated with hetIL-15. Importantly, we found that hetIL-15 preferentially enriched Pmel-1 cells in the tumor sites. hetIL-15 treatment also supported proliferation and cytotoxic function of tumor-infiltrating Pmel-1 cells, while reducing their expression level of PD-1, and resulted in improved tumor control and survival benefit. Thus, hetIL-15 administration improves the outcome of ACT in non-lymphodepleted hosts, and can be a valuable addition to strategies for cancer immunotherapy.

Citation Format: Sinnie Ng, Cristina Bergamaschi, Bethany Nagy, Candido Alicea, Shawn M. Jensen, Bernard A. Fox, Barbara K. Felber, George N. Pavlakis. Heterodimeric IL-15 enhances tumor infiltration, persistence and effector functions of adoptively transferred tumor-specific T cells in the absence of lymphodepletion. [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 LB-088.
Abstract LB-093: Vaccine based immunotherapy regimen (VBIR) for the treatment of prostate cancer
Authors: Cho Helen , Cockle Paul , Joe Binder , Risini Weeratna , White Phil , Jooss Karin
Published: July 2016

A successful cancer vaccine will activate the host immune system to induce a balanced T- and B-cell response to tumor-specific antigens that can lead to tumor regression. Effective cancer vaccines will need to overcome several challenges to accomplish this goal, such as to break tolerance to the tumor associated antigens which are mostly self antigens, induce and maintain high tumor-specific T-cell titers to keep the immune pressure on the tumor as well as to overcome the immune suppressive tumor microenvironment to keep the T-cells active at the tumor site. We have applied the lessons learned in the field to the development of a multi-component cancer immunotherapy regimen that has entered clinical testing at the beginning of 2016 for the treatment of patients with prostate cancer. The vaccine regimen consists of a chimpanzee adenovirus prime vaccination administered intramuscularly followed by DNA boost vaccinations delivered with an electroporation device and with each vaccination low dose of an anti-CTLA4 antibody is administered locally, in close proximity of the vaccine draining lymph nodes. The adenovirus and DNA express the three prostate cancer antigens PSA, PSMA and PSCA. Lastly, sutent or anti-PD-1 is added to the regimen to counter the immune suppressive tumor microenvironment by lowering myeloid derived suppressor cells (by sutent doses that are lower than the approved clinical dose) or interfering with the PD-L1/PD-1 signaling pathway (by anti-PD-1). Data will be presented in tumor-bearing mice and non human primates (NHPs) demonstrating the attributes of the heterologous prime/boost vaccine with local anti-CTLA4 that induces potent, polyclonal and functional tumor-antigen specific T- and B cell responses that are maintained at high levels for up to a year in NHPs. We could also demonstrate that low dose of sutent is highly effective at lowering MDSCs in tumors and the periphery of tumor bearing mice, resulting in significantly enhanced potency of a heterologous prime/boost cancer vaccine. Lastly, our data suggest that - in the context of active vaccination - local delivery of anti-CTLA4 is superior to systemic delivery of the immune modulator at enhancing vaccine induced T-cell responses, thereby broadening the therapeutic window of the immune modulator.

Citation Format: Helen Cho, Paul Cockle, Binder Joe, Weeratna Risini, Phil White, Karin Jooss. Vaccine based immunotherapy regimen (VBIR) for the treatment of prostate 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 LB-093.
Abstract LB-119: Single-cell live imaging of paclitaxel-resistant cancer cell generation
Authors: Niu Na , Zhang Jie , Zhang Ning , Mercado-Uribe Imelda , Tao Fangfang , Han Zhenbo , Pathak Sen , Multani Asha , Kuang Jian , Yao Jun , Bast Robert , Sood Anil , Hung Mien-Chie , Liu Jinsong
Published: July 2016

Polyploid giant cancer cells (PGCCs) are abundant in cancers after chemotherapy. PGCCs have generally been considered nonviable because of their inability to execute mitosis. However, our recently reported studies challenged this paradigm by showing that PGCCs were capable of tumor initiation. To understand the role of PGCCs in chemoresistance, we monitored paclitaxel-induced PGCCs by conventional and live-cell fluorescence time-lapse recording. We found that paclitaxel induced massive cell death but also initiated endoreplication to form PGCCs. These PGCCs continued to grow via endoreplication, endomitosis, or cytofission before generating new mononuclear or multinucleated daughter cells via nuclear fragmentation or budding. These daughter cells resumed mitosis with a new stable karyotype and exhibited drug resistance. Budding from PGCCs was also observed in chemotherapy-treated ovarian cancer specimens from patients. On the basis of our findings, we propose the existence of an amitotic giant cell cycle composed of four phases: initiation, maintenance, termination, and speciation. We believe this is the first report of fluorescent live-cell imaging of the birth of resistant cancer cells at the single-cell level in response to paclitaxel treatment. Our findings provide strong evidence that a stress-induced amitotic giant cell cycle may be a programmed event underlying chemotherapy resistance and cancer relapse.

Citation Format: Na Niu, Jie Zhang, Ning Zhang, Imelda Mercado-Uribe, Fangfang Tao, Zhenbo Han, Sen Pathak, Asha Multani, Jian Kuang, Jun Yao, Robert Bast, Anil Sood, Mien-Chie Hung, Jinsong Liu. Single-cell live imaging of paclitaxel-resistant cancer cell generation. [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 LB-119.
Abstract LB-128: High prevalence of elevated TRPV6 mRNA in pancreatic ductal adenocarcinoma
Authors: Lutes Tyler , Dugourd Dominique , Davey Michelle , Rice Christopher , St-Pierre Stephanie , Stewart Jack M.
Published: July 2016

SOR-C13, a 13-mer peptide derived from soricidin, the paralytic protein component of saliva of the Northern Short-tailed shrew, just completed an open-label, all comers phase I clinical trial for the treatment of epithelial-derived cancers. SOR-C13 is a first-in-class drug candidate that specifically targets and inhibits the TRPV6 calcium channel - a recognized oncochannel over-expressed in a number of epithelial cancers (e.g. breast, ovarian, prostate). TRPV6 over-expression is associated with a poor prognosis particularly with breast and prostate cancers. SOR-C13 is the first TRPV6-targeting drug to enter clinical development. Pancreatic patients were enrolled in the phase I clinical trial for SOR-C13 and for this reason the TRPV6 gene expression in pancreatic tumour biopsies was assessed. Association of TRPV6 oncochannel expression with aggressive pancreatic adenocarcinoma compared to neuroendocrine tumours has never been investigated. Pancreatic adenocarcinoma represents 90% of the pancreatic tumours and is associated with a poor prognosis compared to neuroendocrine tumours. TRPV6 gene expression was assessed in 19 pancreatic tumor biopsies including five adenocarcinoma (Grade I to III), one acinar cell (exocrine), and 13 neuroendocrine (Islet cell) tumors by two-step RT-qPCR. TRPV6 and β-actin (reference gene) mRNA expression was evaluated in duplicate in a reproducible TRPV6 plus β-actin duplex two-step RT-qPCR assay. The acinar cell, and 69% (9/13) of the neuroendocrine tumors had no detectable TRPV6 mRNA expression with >90% of neuroendocrine tumors (12/13) having very little TRPV6 mRNA expression (<30 copies/ng RNA). Of the five pancreatic adenocarcinoma biopsies 4/5 (80%) had 67-285 copies of TRPV6 mRNA/ng RNA, indicating a high level of TRPV6 expression in this type of aggressive pancreatic cancer. The β-actin CT was between 24 and 30 for all tumours (mean 28.5 ± 1.2) indicating that the lack TRPV6 amplification in a majority of the neuroendocrine tumors was not due to RT-qPCR failure or a lack of quality of the biopsy cDNA. Results indicate that drugs specifically targeting TRPV6 oncochannel, like SOR-C13, have the potential to be used to treat the high medical need in pancreatic ductal adenocarcinoma.

Citation Format: Tyler Lutes, Dominique Dugourd, Michelle Davey, Christopher Rice, Stephanie St-Pierre, Jack M. Stewart. High prevalence of elevated TRPV6 mRNA in pancreatic ductal adenocarcinoma. [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 LB-128.
Abstract LB-131: Birinapant and carboplatin co-therapy can effectively target platinum resistant ovarian cancer initiating cells
Authors: La Vincent , Fujikawa Rachel , Janzen Deanna , Bainvoll Liat , Memarzadeh Sanaz
Published: July 2016

High-grade serous ovarian cancers (HGSOCs) contain CA125-negative cancer-initiating cells resistant to standard platinum therapy. High expression of cellular inhibitors of apoptosis proteins (cIAPs) in these platinum resistant HGSOC initiating cells causes resistance to apoptosis despite platinum-induced DNA damage. cIAPs can be degraded with the addition of birinapant, a SMAC-mimetic, sensitizing cancer initiating cells to carboplatin and resulting in their elimination. Using in vitro drug assays, we demonstrate that more than half of human HGSOCs (13/23 independent samples) can be targeted with birinapant and carboplatin co-therapy. Importantly, treatment with this co-therapy eliminated tumor cells irrespective of their clinically-defined platinum sensitivity suggesting that this therapeutic approach could be efficacious with patient who have platinum sensitive and/or resistant disease. Pre-clinical trials in mice bearing intra-peritoneal low-passage human-derived HGSOC cell lines demonstrate that birinapant and carboplatin co-therapy significantly improves overall survival. A vast majority of co-therapy treated mice are still alive, 5 months after all animals treated with vehicle or carboplatin monotherapy have succumbed to tumor. Given that co-therapy was efficacious in approximately 50% of HGOSCs, evaluation of biomarkers that can predict this response are clinically relevant. The expression of cIAP levels were quantified using western blot and then immunohistochemistry in the CA125 negative fraction of our 23 clinical samples. We found that expression of ≥24ng of cIAP in the CA125-negative HGSOC cell lysate could accurately predict response to co-therapy with 100 percent accuracy. Detection and quantification of cIAP in CA125 negative cells by immunohistochemistry (IHC) could also predict a response to co-therapy with 95 percent accuracy. We report on careful analysis of two sets of biomarkers specifically measuring druggable targets in ovarian cancer initiating cells that could predict a response to co-therapy with birinapant and carboplatin. This therapeutic approach, that can overcome platinum resistance in ovarian cancer initiating stem cells, will be tested in an upcoming clinical trial alongside our proposed companion diagnostic biomarkers of response.

Citation Format: Vincent La, Rachel Fujikawa, Deanna Janzen, Liat Bainvoll, Sanaz Memarzadeh. Birinapant and carboplatin co-therapy can effectively target platinum resistant ovarian cancer initiating 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 LB-131.
Abstract LB-161: Exploiting non-canonical heterochromatin-mediated telomere protection mechanisms in human cells
Authors: Chow Tracy T. , Blackburn Elizabeth H.
Published: July 2016

Mammalian telomeres are inherently heterochromatic. While enhanced telomere maintenance is evident in malignant cancers, some cancers appear to maintain telomeres by neither the common telomerase nor the alternative telomere repeat recombination mechanisms. Specifically, the roles of epigenetic modifications in telomere protection are largely unknown in human cancers. I have combined newly developed cellular and molecular approaches to show that in some cancer cell types, experimentally enhanced heterochromatinization localized specifically at telomeres reduced damage-induced foci at telomeres, suggesting augmentation of telomere stability. These results lead to the intriguing hypothesis that manipulating the epigenetic status at telomeres may be exploited to elicit damage at the telomeres of cancer cells as a novel approach to fight cancer. My current work in progress focuses on identifying novel chromatin modifiers that weaken telomere protection by modulating telomere compaction. It is especially urgent to understand the plasticity and modes of telomere protection by which some human cancers escape the requirement of telomerase activation to sustain immortalization. Results from this work can potentially advance the development of novel combinatorial telomere-directed cancer treatments.

Citation Format: Tracy T. Chow, Elizabeth H. Blackburn. Exploiting non-canonical heterochromatin-mediated telomere protection mechanisms in human 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 LB-161.
Abstract LB-195: The intronic DPYD variant rs75017182 correlates with a modest reduction in DPD enzyme activity
Authors: Shrestha Shikshya , Offer Steven M. , Diasio Robert B.
Published: July 2016

Nearly one-third of cancer patients that receive the commonly prescribed chemotherapy drug 5-fluorouracil (5-FU) experience severe (grade 3+) adverse toxicity related to treatment. Approximately 1,300 deaths are directly attributed to 5-FU toxicity annually in the U.S. While three deleterious genetic variations in the dihydropyrimidine dehydrogenase (DPD) gene (DPYD) are well-established predictors of severe toxicity (i.e., *2A, p.I560S, p.D949V), they only explain 30-35% of adverse cases of 5-FU toxicity. Recently, an intronic variant (rs75017182) has been suggested to contribute to 5-FU toxicity risk by promoting the alternative splicing of DPYD. However, recent clinical studies are conflicting as to the degree to which rs75017182 affects DPD enzyme function, and it remains unclear as to the extent to which DPYD splicing is affected in carriers. The primary aim of this study was to directly determine correlations between rs75017182, DPD enzyme function, and DPYD splicing. Genotyping for rs75017182, *2A, p.I560S, and p.D949V was performed on DNA obtained from 3950 healthy participants in the Mayo Clinic Biobank. Individuals carrying one or more of the genotyped variants, as well as matched non-carriers, were asked to provide an additional blood sample that was used to measure DPYD expression, DPYD splicing relevant to rs75017182, and DPD enzyme activity (n = 204). A moderate, but significant, reduction was noted in the expression of canonically spliced DPYD in rs75017182 carriers compared to non-carriers. DPD enzyme activity in peripheral blood mononuclear cells was similarly reduced in rs75017182 carriers. The degree to which DPD activity was reduced in rs75017182 carriers was not as severe as was noted for carriers of the toxicity-associated variants *2A, p.I560S, or p.D949V. Collectively, our data support a model in which rs75017182 leads to alternative splicing of a fraction of primary transcripts that harbor the variant, which in turn causes a modest reduction in the levels of functional DPD enzyme. The modest phenotypes noted may partially explain some of the discrepant results noted between various clinical studies that have attempted to evaluate the variant.

Citation Format: Shikshya Shrestha, Steven M. Offer, Robert B. Diasio. The intronic DPYD variant rs75017182 correlates with a modest reduction in DPD enzyme activity. [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 LB-195.