bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 98: The somatic mutational landscape of the mitochondrial genome in prostate cancer: evaluation of clinical impact
Authors: Hopkins Julia F. , Sabelnykova Veronica Y. , Watson John , Heisler Lawrence E. , Zhang Junyan , Fraser Michael , van der Kwast Theodorus , Bristow Robert G. , Boutros Paul C.
Published: July 2016

Prostate cancer remains the most prevalent and second most lethal non-skin cancer in men. Whole genome studies have provided important insights into specific driver genes, however most of these studies have not assessed one key portion of the genome: the mitochondrial genome. To gain a complete understanding of the most commonly-diagnosed sub-groups of prostate cancer: low- and intermediate-risk localized disease, we surveyed the mitochondrial genomes from next-generation sequencing (NGS) data of over 300 tumour samples from prostate cancer patients. These samples were mainly from prostate cancer patients with clinical Gleason Scores of 3+3, 3+4 and 4+3. All had at least 5 years of follow-up data (median > 8 years), allowing identification of clinical associations with identified somatic mutations via Cox Proportional Hazards modeling and machine-learning. Recurrent somatic mutations in mtDNA were identified, and these were associated with clinical outcomes. One third of patients were found to have a somatic mtDNA mutation. These mutations appear to be associated with age of patient. The mtDNA region with the majority of mutations was the regulatory D-loop region, although certain proteins had high numbers of mutations. Those somatic mutations occurring within the coding regions in general were nonsynonymous. Specific identified candidate somatic mutations were validated via Sanger sequencing. Clinical associations between somatic were also integrated with existing copy-number alteration (CNA) biomarkers using machine learning methods to evaluate performance. mtDNA mutations were also compared to identified aberrations (CNA, PGA, SNVs) within the nuclear genome to determine correlations between the two genomes, in addition to other somatic mutations or altered-expression in nuclear-encoded mitochondrial proteins. Taken together, these data demonstrate a key role for mitochondrial mutations in driving prostate cancer.

Citation Format: Julia F. Hopkins, Veronica Y. Sabelnykova, John Watson, Lawrence E. Heisler, Junyan Zhang, Michael Fraser, Theodorus van der Kwast, Robert G. Bristow, Paul C. Boutros. The somatic mutational landscape of the mitochondrial genome in prostate cancer: evaluation of clinical impact. [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 98.
Abstract 984: LncRNA LINC00668 predicts a poor prognosis of gastric cancer and promotes cell proliferation through epigenetically silencing of CKIs
Authors: Chen Jinfei
Published: July 2016

Recently, long noncoding RNAs (lncRNAs) have been shown to have important regulatory roles in human cancer biology. By utilizing publicly available lncRNAs expression profiling data of gastric cancer and integrating analyses, we screened out LINC00668, whose expression is significantly increased and is correlated with outcomes in gastric cancer (GC). Further experiments revealed that LINC00668 knockdown significantly repressed the proliferation both in vitro and in vivo. Mechanistic investigations showed that LINC00668 was a direct transcriptional target of E2F transcription factor 1 (E2F1). Moreover, we also found that LINC00668 plays a key role in G0/G1 arrest, and further demonstrated that LINC00668 was associated with PRC2 and that this association was required for the epigenetic repression of cyclin-dependent protein kinase inhibitors (CKIs), including p15, p16, p21, p27 and p57, thus contributing to the regulation of gastric cancer cell cycle. To our knowledge, this is the first report showed that the role and molecular mechanism of LINC00668 in cancer. Together, our results suggest that E2F1-regulated LINC00668, as a cell cycle regulator, enriches a mechanistic link between lncRNA and E2F1-mediated cell cycle regulation pathway and may serve as a candidate prognostic biomarker and target for new therapies in human gastric cancer.

Key words: E2F1; LINC00668; cell cycle; proliferation; gastric cancer

Acknowledgements: The work was partly supported by the National 973 Basic Research Program of China (Grant No. 2013CB911300) grants from the National Natural Science Foundation of China (Grant No. 81272469, 81502071 and 81572928) and the clinical special project for Natural Science Foundation of Jiangsu Province (Grant No. BL2012016), and the grant from Nanjing 12th Five-Year key Scientific Project of medicine to Dr. Jinfei Chen.

Citation Format: Jinfei Chen. LncRNA LINC00668 predicts a poor prognosis of gastric cancer and promotes cell proliferation through epigenetically silencing of CKIs. [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 984.
Abstract 985: Downregulation of long noncoding RNA TINCR promotes invasion and metastasis and predicts poor prognosis in tongue squamous cell carcinoma
Authors: Zhuang Zehang , Wang Cheng , Xie Nan , Wu Yue , Hou Jinsong , Liu Xiqiang , Huang Hongzhang
Published: July 2016

Background and aim: Recently long non-coding RNAs (lncRNAs) have emerged as new gene regulators involving in a number of developmental and tumorigenic processes. However, few lncRNAs have been well characterized in tongue squamous cell carcinoma (TSCC). The aim of this study is to determine whether lncRNAs play a role in TSCC progression.

Methods: The expression profiles of lncRNAs and protein-coding genes in TSCC tissues and paired adjacent non-tumor tissues from 10 patients were compared by using lncRNA microarrays. TSCC-specific gene co-expression networks were constructed by differential expression analysis and weighted gene co-expression network analysis (WGCNA). Levels of these differentially expressed lncRNAs were verified in TSCC tissues (n = 45) using Quantitative real-time PCR (qRT-PCR) and further confirmed in another patient cohort (n = 103) by in situ hybridization (ISH). The effects of lncRNA on tumor cell invasion and migration were assessed by silencing or overexpressing the lncRNA in vitro.

Results: A total of 815 lncRNAs and 1783 protein-coding genes were differentially expressed between TSCC tissues and paired adjacent non-tumor tissues. WGCNA showed that one of the co-expression networks was significantly enriched for biological process that was relevant to epithelial cell differentiation, among which, TINCR was significantly down-regulated. Both PCR and ISH analyses validated that the down-regulation of TINCR in tumor tissues compared with controls. The expression level of TINCR was associated with tumor size, differentiation, cervical lymph node metastasis status, clinical stage and outcomes in patients with TSCC.Patients with TINCR low expression had a reduced overall survival. COX regression analysis showed that TINCR can be served as an independent prognostic factor for patients with TSCC. More, ectopic transfection of TINCR dramatically suppressed cell invasion and migration in vitro. On the contrary, knockdown of TINCR led to p63 upregulation, and enhanced cell invasion and migration.

Conclusion: Our study suggests that downregulation of TINCR plays a role in TSCC progression, at least partially, by regulating epithelial differentiation-associated genes.

Citation Format: Zehang Zhuang, Cheng Wang, Nan Xie, Yue Wu, Jinsong Hou, Xiqiang Liu, Hongzhang Huang. Downregulation of long noncoding RNA TINCR promotes invasion and metastasis and predicts poor prognosis in tongue squamous cell carcinoma. [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 985.
Abstract 987: A novel cell cycle-associated lncRNA, HOXA11-AS, is transcribed from 5-prime end of HOXA transcript and a biomarker of progression in glioma
Authors: Wang Qixue , Zhang Junxia , Liu Yanwei , Zhou Junhju , Kang Chunsheng , Han Lei
Published: July 2016

The comprehensive lncRNA expression signature in glioma remains fully unknown. We performed a high throughput microarray to detect ncRNA expression profile in 225 human glioma tissues. One novel lncRNA, HOXA11-AS with unknown function, is the antisense transcript of HOX11 gene. The results showed that HOXA11-AS was closely associated with glioma grade and poor prognosis. Multivariate cox regression analysis revealed that HOXA11-AS was an independent prognostic factor in glioblastoma multiforme patients and its expression was correlated with glioma molecular subtype of the Cancer Genome Atlas. Gene set enrichment analysis indicated that gene sets most correlated with HOXA11-AS expression involved in cell cycle progression. Overexpression of HOXA11-AS transcript promoted cell proliferation in vitro while knockdown of HOXA11-AS expression manifested a repressive function during these cellular processes via regulating cell cycle progress. The growth promoting and inhibiting effect of HOXA11-AS was also demonstrated in a xenograft mouse model. For the first time, our data confirms that HOXA11-AS is an important long non-coding RNA that primarily serves as a prognostic factor for glioma patient survival, a biomarker for identifying glioma molecular subtypes, and therapeutic target for glioma patient.

Citation Format: Qixue Wang, Junxia Zhang, Yanwei Liu, Junhju Zhou, Chunsheng Kang, Lei Han. A novel cell cycle-associated lncRNA, HOXA11-AS, is transcribed from 5-prime end of HOXA transcript and a biomarker of progression in glioma. [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 987.
Abstract 999: P16 DNA methylation inactivates transcription of IncRNA ANRIL
Authors: Gan Ying , Zhang Baozhen , Cui Chenghua , Deng Dajun
Published: July 2016

The exonic ANRIL (P15AS) is a 3.8-kb lncRNA transcribed from the antisense strand of the P14 promoter and flanking regions. Recently, we have constructed a P16 promoter DNA methyltransferase (P16-Dnmt) using the pTRIPZ vector that can specifically methylate human P16 CpG islands and found that P16 methylation directly leads to gene transcription silence [Cui et al. Genome Biology 2015, 16:252]. However, whether ANRIL transcription is affected by P16 DNA methylation has not previously been reported. In the present study, correlation between endogenous P16, P15, P14 mRNA and ANRIL levels in a panel of cell lines were determined using quantitative RT-PCR. Unexpectedly, the results showed that ANRIL transcriptional level was positively and significantly correlated with the P16 mRNA level (r = 0.774, P = 0.003), but not correlated with the P15 or P14 mRNA levels (r = 0.09 or 0.30, P = 0.78 or 0.35). These phenomena were confirmed using the public available transcriptome data in the Broad-Novartis Cancer Cell Line Encyclopedia (CCLE). Furthermore, transcription of both ANRIL and P16 mRNA were observed only in cancer cell lines in which the P16 alleles are unmethylated (Caski, SGC7901, BGC823, GES1, Siha and HeLa), but not in these cell lines in which the P16 alleles are fully methylated (Colo205, PC3, MHCC97H, RKO, SW480 and AGS). These suggest the possibility that methylation of the P16 promoter may inactivate transcription of ANRIL as well as P16. To study the possible causality between P16 DNA methylation and transcriptional silence of ANRIL, we employed P16-Dnmt to induce P16-specific DNA methylation in gastric cancer BGC823 cells, and found that transcription levels of both P16 and ANRIL were significantly decreased by the induced P16 DNA methylation (P<0.001 and 0.024, respectively). Besides, transcription level of P14 was also reduced (P = 0.043) while the P14 promoter CpG islands remained to be unmethylated. In contrast, P16 DNA demethylation induced by an artificial P16-specific transcription factor [Zhang et al. Human Gene Therapy 2012, 23:1071-81] re-activated transcription of both ANRIL and P16 in H1299 cells (P<0.001). The mechanism of inactivation of ANRIL expression by P16 DNA methylation is under investigation. In conclusion, transcription of ANRIL is regulated by P16 DNA methylation.

Citation Format: Ying Gan, Baozhen Zhang, Chenghua Cui, Dajun Deng. P16 DNA methylation inactivates transcription of IncRNA ANRIL. [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 999.
Abstract CT121: Demographics of clinical trial participants for new molecular entity (NME) oncology drugs and biologics approved by FDA CDER in 2015
Authors: Wright Hilary , Elahi Merina , Igun Ayomide , Soon Greg , Chen Alice , Pariser Anne , Fadiran Emmanuel
Published: July 2016

Background: In 2015, approximately 810,100 new cancer cases were diagnosed in females in the US. To facilitate the assessment of efficacy and safety of medical products in the diverse populations who might use them after approval, the Food and Drug Administration (FDA) has implemented guidance and regulations to encourage greater participation of women and minorities in clinical trials (CTs).

Objectives: To assess demographics in oncology CTs submitted in support of “new drugs” (i.e., New Molecular Entity New Drug Applications (NME NDAs) and original Biologics License Applications (BLAs)) approved by the FDA's Center for Drug Evaluation and Research (CDER) in 2015.

Methods: Participation by sex, race, and age (<65 years, ?65 years) and presence of sex-based efficacy and safety analyses were assessed from sponsors’ final clinical study reports for new oncology drugs for adult indications approved in 2015. Sex-based analyses were coded as exploratory or conclusive as previously reported.,

Results: Fourteen new oncology drugs were approved by CDER in 2015. One BLA and one NDA were excluded from the analysis because they were for pediatric or sex-specific indications. For the 12 remaining drugs, there were 188 trials (phase 1, 2, or 3) that included a total of 17,702 subjects, 48.1% of whom were women. Of the subjects for which race was reported (94.2% of the total), 78.0% were Caucasian, and of those for which age group was reported (75.3% of all subjects), 33.4% were ?65 years of age. Women were 43.1%, 53.2%, and 53.9% of subjects in phase 1, 2, and 3 CTs, respectively. PPR, defined as the Ratio of the Proportion of women in the indicated disease population in the CTs to the Proportion of women in the disease population, was ?0.8 for 11 new drugs and <0.8 for one new drug. Eleven new drugs included both efficacy and safety sex-based analyses, and one new drug included only efficacy sex-based analysis.

Conclusions: Relative to their proportion in the disease population, female participation was comparable to (i.e., PPR between 0.8 and 1.2) or greater than men's in late-phase trials for 11 of the 12 oncology drugs examined. Female participation in early-phase CTs was lower than in late-phase CTs; however, late-phase clinical trials are typically where FDA's risk-benefit assessments are made.

Citation Format: Hilary Wright, Merina Elahi, Ayomide Igun, Greg Soon, Alice Chen, Anne Pariser, Emmanuel Fadiran. Demographics of clinical trial participants for new molecular entity (NME) oncology drugs and biologics approved by FDA CDER in 2015. [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 CT121.
Abstract CT127: Results from a phase II clinical study in Chinese population: treatment with Chinese medicine cocktail LQ for patients with stage IIIB/IV advanced non-small cell lung cancer
Authors: Zhang Lei , Wu Chengyu
Published: July 2016

OBJECTIVES: To estimate the response of Chinese medicine “cocktail” LQ in patients with advanced non-small cells lung cancer, a phase II multicenter, double-blind, randomized clinical trial was conducted. Patients with IIIB/IV stage received LQ and natural product control Spirulina. The end points for this study included overall survival (OS), progression free survival (PFS), safety of the regimen, disease control rate (DCR) and other criteria.

METHODS: Patients with stage IIIB/IV advanced NSCLC cancer received LQ treatment and Spirulina. Toxicity was assessed. Quality of life was assessed. The primary objective was overall survival.

RESULTS: A hundred and twenty patients were enrolled and 80 were treated. Median age was 60 years (range, 42-75). The median overall survival rate in LQ group and Spirulina group is 10.9 months vs 7.4 months respectively (p<0.0001). Median progression survival free survival is 3.84 months vs 1.97 months in LQ and Spirulina group (p<0.01). There is no side effect were found in there. There were 42 patients with stable disease with the disease control rate of 59.15% in LQ treatment group, Compare with Spirulina group, there were only 4 standard disease, for disease control rate of 11.76% (p<0.001). There are no notable toxicities were found in LQ treatment group.

CONCLUSIONS: This first-in-human phase II study of Chinese medicine cocktail LQ used as first-line therapy in patients with advanced NSCLC. LQ, a promising new drug, provides a safer and high effective therapy for late-stage lung cancer patients.

Citation Format: Lei Zhang, Chengyu Wu. Results from a phase II clinical study in Chinese population: treatment with Chinese medicine cocktail LQ for patients with stage IIIB/IV advanced non-small cell lung 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 CT127.
Abstract CT154: Phase I dose-escalating PoC study to evaluate the safety and tolerability of LiPlaCis (liposomal cisplatin formulation) in patients with advanced or refractory tumors
Authors: Lassen Ulrik , Mau-Sørensen Morten , Hald Buhl Ulla , Madsen Mogens W. , Balslev Eva , Pluim Dick , Schellens Jan H. M. , Knudsen Steen , Jensen Peter B.
Published: July 2016

LiPlaCis is a novel liposomal formulation of cisplatin, designed to be specifically degraded by secretory phospholipase A2 (sPLA2) which is over-expressed in tumor tissue. sPLA2 has been shown to be present in a number of different tumor tissues - e.g. prostate, lung, ovarian, breast etc. (T. Abe 1997). Thus, LiPlaCis is intended to improve the therapeutic index due to an improved therapeutic efficacy and possibly also an improved safety and tolerability profile. Objectives: The primary objectives were safety and determination of MTD. Secondary objectives were evaluation of PK, clinical activity, and PD. This included two PoC cohorts to study platinum-DNA adducts in tumor compared to normal tissue following administration of LiPlaCis. Methods: A standard 3+3 design was used to include patients with advanced solid tumors and PS 0-1. LiPlaCis was administered weekly on day 1, day 8 and possibly day 15 every 3 wks. CTCAE v4.03 and RECIST were used to assess safety and tumor activity. Paired tumor and normal tissue biopsies obtained pre-treatment and on day 2 were used to assess sPLA2-IIA protein levels and platinum-DNA adducts (by 32P-postlabeling assay) in two PoC cohorts of 60 and 90 mg LiPlaCis. Results: A total of 16 patients were included at dose levels of 60, 90 and 120 mg. At 120 mg two DLTs were observed and an intermediate dose level of 90 mg Day 1 and 8 and 45 mg Day 15 was explored. After 1 DLT, this dose level was halted and the PoC cohorts were initiated sequentially. The observed DLTs included renal toxicity and infusion reactions. Most frequent AEs of all grades were fatigue, hypomagnesemia and vomiting. The most common (>10%) grade 3-4 AEs were hypomagnesemia, hypokalemia and anemia. Clinical activity was observed in a patient with H&N cancer; 60 mg (PR), SCC skin;120 mg (PR), BC; 60 mg (SD-ongoing), CRC; 90 mg (SD -18 wks) and gastric cancer; 90 mg (SD-21 wks). In the 60 mg PoC cohort of 3

pts the tumor- to normal tissue ratio of platinum-DNA adducts was from 5.7 to 8.3 fold. Conclusion: MTD has not yet been determined, but ongoing PoC cohorts indicate that LiPlaCis is preferably released in tumor by sPLA2 compared to normal tissue which potentially could improve the therapeutic index of cisplatin.

Citation Format: Ulrik Lassen, Morten Mau-Sørensen, Ulla Hald Buhl, Mogens W. Madsen, Eva Balslev, Dick Pluim, Jan H. M. Schellens, Steen Knudsen, Peter B. Jensen. Phase I dose-escalating PoC study to evaluate the safety and tolerability of LiPlaCis (liposomal cisplatin formulation) in patients with advanced or refractory tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT154.
Abstract CT160: Clinical application of a natural polypeptide, poly-γ-glutamic acid, which has immunotherapeutic efficacy
Authors: Lee Jae-Kwan , Min Kyung-Jin , Kim Kwang , Poo Haryoung , Sung Moon-Hee
Published: July 2016

Poly-gamma-glutamic acid (γ-PGA) is known as viscous component of Korean chungkookjang and a natural polypeptide consisting of only glutamic acid with gamma-amide linkages. High molecular weight γ-PGA was isolated and mass-produced from Bacillus subtilisChungkookjang. Previously, accumulating evidences indicate that the γ-PGA inducesinnate immune response including natural killer (NK) cell activation and interferon secretion throughtoll-like receptor 4 (TLR4). To evaluate the immunotherapeutic effects, we’ve investigated the effect of γ-PGA on human NK cell activity and antiviral effect. First human study involving 99 healthy volunteers revealed thathigh-dosage γ-PGA group were significantly higher cytotoxic activities of NK cells than the low dosage and placebo groups at weeks 4 and 8 after the treatment. Furthermore, westudied the effect of γ-PGA on the treatment of vaginal intraepithelial neoplasia (VAIN). A retrospectiveobservational study on γ-PGA therapy for biopsy-proven VAIN suggest that γ-PGA may be helpful for the cytological regression and reduction of viral load in patients with high-risk HPV-positive VAIN. Since previous human studies showed the possibility of drug, we have accomplished a phase I dose escalation study to determine the safety, tolerance and pharmacokinetics of γ-PGA in healthy adult male subjects. The phase I study of oral γ-PGA was conducted in 20 healthy volunteers. There was no any significant difference in abnormal diagnoses or clinically relevant changes in laboratory parameters, vital signs, or other safety parameters. Currently, we have initiated a phase II trial to determine the efficacy and safety of γ-PGA compared with placebo in patients with cervical intraepithelial neoplasia grade 1 (CIN1). Total 200 patients with CIN1 will be administered with γ-PGA or placebo for 4 weeks followed by 8 weeks observation and compare the regression rate of CIN1.So far there was no serious adverse event (SAE) during phase II study. These results indicate that the oral administration of γ-PGAcan serve as treatment option that are safe and clinical efficacy via inducing NK cell activity and anti viral effect.

Citation Format: Jae-Kwan Lee, Kyung-Jin Min, Kwang Kim, Haryoung Poo, Moon-Hee Sung. Clinical application of a natural polypeptide, poly-γ-glutamic acid, which has immunotherapeutic efficacy. [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 CT160.
Abstract LB-001: Functional role of Pak1/Erk signaling in Rac1-related diseases
Authors: Araiza-Olivera Daniela , Chernoff Jonathan
Published: July 2016

The RAS/MAPK signaling pathway regulates key cellular processes, including proliferation, differentiation, and survival. Somatic mutations of the RAS pathway are found in 30% of human cancers, including pancreatic, colon, thyroid, lung and melanoma. Furthermore, germ-line mutations in this pathway, collectively termed Rasopathy syndromes, cause abnormal development. Affected patients often present with cognitive defects, heart problems, facial aberrancies, skin abnormalities and in some cases a predisposition to cancer.

As p21-activated kinases (Paks) have been shown to be required for the activation of ERK by Ras, we evaluated Pak1 and its activator Rac1 as potential therapeutic targets in both Rasopathies and in melanoma. Using a zebrafish model, we first asked if the phenotypic consequences of Ras pathway overactivation during development could be blocked by Pak small molecule inhibitors. Introducing gain-of-function genes such as BRAF V600E, KRAS 4AG12V, and Rac1 P29S into one-cell zebrafish embryos produced a Rasopathy phenotype, characterized by abnormal head and heart development. These phenotypes were suppressed by a Pak-specific small molecule inhibitor. pERK and pPAK levels were increased in embryos expressing BRAF V600E, KRAS 4AG12V, or Rac1 P29S, and were restored to baseline upon addition of Pak1 or Rac1 small molecule inhibitors. We then studied the effect of these small molecule inhibitors in human malignant melanoma cell lines bearing activating mutations in BRAF, PREX (an activator of Rac1), and/or RAC1. Treatment with PAK or RAC inhibitors decreased the migration and proliferation of cells with mutant PREX or RAC1 mutations, but not those with BRAF mutations; the reverse was true when these cells were treated with a BRAF inhibitor. These data suggest that Pak1 might serve as a useful therapeutic target in PREX- or RAC1-driven cancers such as malignant melanoma.

Citation Format: Daniela Araiza-Olivera, Jonathan Chernoff. Functional role of Pak1/Erk signaling in Rac1-related diseases. [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-001.
Abstract LB-007: Interaction between integrin α4β1 and IGF1 and its role in IGF signaling in hematologic malignancies
Authors: Cedano Prieto Dora M. , Yu Jessica , Takada Yoko , Takada Yoshikazu
Published: July 2016

Integrins are transmembrane αβ heterodimers that function as cell adhesion receptors. Integrins are aberrantly overexpressed in cancer cells and also in tumor-associated cells. They are involved in cancer cell proliferation, invasion and survival. It has been proposed that the interaction between integrin α4β1, a major integrin in hematologic cancer, and VCAM-1 and fibronectin is responsible for drug resistance in these malignances, since antagonists to this integrin reduce drug resistance. However these results are based on the assumption that VCAM-1 and fibronectin are the only ligands for α4β1. Insulin-like growth factor 1 (IGF1) signaling plays a critical role in drug resistance and radio resistance hematologic cancer. IGF1 is a polypeptide hormone that binds to tyrosine kinase receptor IGF1R and activates the PI3K/Akt signaling pathway. This pathway is involved in cell proliferation, survival, and inhibition of apoptosis. In various types of cancer IGF1 is over expressed and the PI3K/Akt pathway is activated at a much higher rate than in normal cells. This results in the growth of cancer cells and resistance to chemotherapy. IGF1 signaling is implicated in drug resistance, and is a good therapeutic target in hematologic cancers. It is unclear if α4β1 and IGF signaling work independently in drug resistance. Recently we established that IGF1 binds to integrins αvβ3 and α6β4, and subsequent integrin-IGF1-IGF1R ternary complex formation is a critical step in IGF signaling in non-hematologic cancer. We developed the R36E/R37E IGF1 mutant that is defective in integrin binding and a dominant-negative antagonist of IGF signaling. Here we show that IGF1 is a ligand for integrin α4β1 and induces a ternary complex with IGF1R and α4β1. Antagonists to integrin α4β1 and the R36E/R37E IGF1 mutant reduced intracellular signaling in Chinese hamster ovary cells expressing human integrin α4 (α4-CHO cells) and also in different hematologic cancer cells such as Reh, Molt-4, U937 and JY cells. These results suggest that integrin α4β1 is involved in IGF signaling through direct binding to IGF1 in hematologic cancer. The α4β1-IGF1 interaction is a novel therapeutic target for drug resistance in hematologic cancer.

Citation Format: Dora M. Cedano Prieto, Jessica Yu, Yoko Takada, Yoshikazu Takada. Interaction between integrin α4β1 and IGF1 and its role in IGF signaling in hematologic 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 LB-007.
Abstract LB-008: KRAS engages AGO2 to enhance cellular transformation
Authors: Shankar Sunita , Pitchiaya Sethuramasundaram , Malik Rohit , Kothari Vishal , Hosono Yasuyuki , Yocum Anastasia K. , Gundlapalli Harika , White Yasmine , Firestone Ari , Cao Xuhong , Dhanasekaran Saravana M. , Stuckey Jeanne , Bollag Gideon , Shannon Kevin , Walter Nils , Kumar-Sinha Chandan , Chinnaiyan Arul M.
Published: July 2016

Oncogenic mutations in RAS provide a compelling yet intractable therapeutic target. Approximately 30% of all cancers harbor activating mutations in the RAS family of small GTPase proteins, making it one of the most common oncogenic aberrations in humans. Normal RAS proteins (H, K or N-RAS) localize to the inner cell membrane and transduce extracellular growth signals by cycling between an “active” GTP-bound state and “inactive” GDP-bound state. Our understanding of RAS biology is primarily from RAS protein-effector interactions that activate a variety of effectors at the plasma membrane like RAF/PI3K/RalGDS. Yet, targeting mutant RAS proteins or its effectors / pathways remains a challenging endeavor for treating RAS driven cancers.

For a comprehensive identification of RAS interactors, we recently performed co-immunoprecipitation (Co-IP) Mass Spectrometric analysis of RAS immunoprecipitates from multiple cancer cell lines with differing KRAS mutation status. In all the cell lines studies, we uncovered an interaction between RAS and the core component of the RNA silencing machinery, Argonaute 2 (AGO2). Endogenously expressed RAS and AGO2 co-sediment and co-localize in intracellular membrane bound endoplasmic reticulum. AGO2 binds the Switch II region in KRAS, irrespective of GDP/GTP bound to RAS. Both endogenous and overexpressed mutant forms of KRAS, attenuate AGO2 related gene silencing function. Using NIH3T3 AGO2-/- cells, we demonstrate that the RAS-AGO2 interaction is required for maximal mutant KRAS expression and cellular transformation. Overall, our studies suggest that through its interaction with AGO2, RAS function extends well beyond its canonical role in intracellular signaling. We will present detailed characterization of the RAS-AGO2 interaction and its functional aspects that we have discovered so far.

Citation Format: Sunita Shankar, Sethuramasundaram Pitchiaya, Rohit Malik, Vishal Kothari, Yasuyuki Hosono, Anastasia K. Yocum, Harika Gundlapalli, Yasmine White, Ari Firestone, Xuhong Cao, Saravana M. Dhanasekaran, Jeanne Stuckey, Gideon Bollag, Kevin Shannon, Nils Walter, Chandan Kumar-Sinha, Arul M. Chinnaiyan. KRAS engages AGO2 to enhance cellular transformation. [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-008.
Abstract LB-011: PAK1 inhibitor FRAX1036 sensitizes ovarian cancer cells with amplified 11q13 to cytotoxic effect of rottlerin
Authors: Prudnikova Tatiana , Chernoff Jonathan
Published: July 2016

p21-activated kinases (PAKs) are Cdc42/Rac-activated serine-threonine protein kinases that regulate several key cancer-relevant signaling pathways, such as the Mek/Erk, PI3K/Akt, and Wnt/b-catenin. Pak1 is frequently overexpressed and/or hyperactivated in different human cancers, including human breast, ovary, prostate, and brain cancer, due to amplification of the PAK1 gene in an 11q13 amplicon. In our previous in vitro and in vivo studies we have shown that ovarian cancer cells with amplified/overexpressed Pak1 were significantly more sensitive to pharmacologic or genetic inhibition of Pak1 compared to cells without 11q13 amplification. In the present study we examined the combination effect of the Pak1 inhibitor FRAX1036 in ovarian cancer cells using ICCB Known Bioactives Library (Enzo). We found that the cytotoxic effect of FRAX1036 was significantly higher when combined with the PKC delta inhibitor, Rottlerin.

We tested FRAX1036 alone and in combination with Rottlerin on 11q13-amplified human ovarian cancer cell lines with respect to cell proliferation, migration and apoptosis. FRAX1036 alone inhibited cell proliferation and migration in 11q13-amplified ovarian cancer cell lines. Co-administration of FRAX1036 with Rottlerin further synergized the inhibition of cell proliferation in vitro and decreased tumor growth in vivo. To explain the synergistic inhibition of cell proliferation induced by the FRAX1036/Rottlerin combination we analyzed Pak1 and PKC delta down-stream signaling molecules. Western blot data indicated that FRAX1036 and Rottlerin synergistically inhibited phosphorylation of critical signaling molecules such as MEK, ERK1/2, b-Catenin, and 4EBP1.

Our findings suggest that Pak1 small molecule inhibitors in combination with Rottlerin hold potential clinical value as chemotherapeutic drugs for the ∼25% of ovarian cancers characterized by PAK1 gene amplification.

Citation Format: Tatiana Prudnikova, Jonathan Chernoff. PAK1 inhibitor FRAX1036 sensitizes ovarian cancer cells with amplified 11q13 to cytotoxic effect of rottlerin. [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-011.
Abstract LB-014: Targeting insulin receptor splicing as a therapeutic intervention for pediatric rhabdomyosarcoma
Authors: Chandler Dawn S. , Brown Chelsea , Bid Hemant , Bebee Thomas , Comiskey Daniel F. , Rigo Frank , Houghton Peter J.
Published: July 2016

The insulin receptor (IN-R) alternatively spliced variant A, encoding a receptor lacking exon 11, is the predominant isoform expressed in both pediatric sarcoma cells and vascular endothelial cells. Exon 11 of the IN-R gene is composed of 36 nucleotides that encode 12-amino acids that reside at the carboxyl terminus of the alpha subunit. Though only a small change in the protein composition, deletion of these 12 amino acids results in a receptor that has increased binding affinity for the IGF-2 growth factor and is exquisitely capable of responding to autocrine and paracrine signaling. Cells expressing both the IN-R A variant and the IGF-2 growth factor are therefore programmed for growth and angiogenesis, two essential steps in tumorigenesis. Furthermore, the IGF-2 can maintain angiogenesis through IN-R A when the IGF-1 receptor is blocked. We also demonstrate that hypoxia induces IN-R alternative splicing. This finding is particularly intriguing since recent studies have shown that adaptation to hypoxic environments is a hallmark of the neoplastic phenotype. We therefore hypothesize that the expression of splicing factors is altered by hypoxia leading to the generation of the IN-R A isoform, which contributes to cancer progression beyond the micrometastatic stage.

To characterize sequence elements and RNA binding proteins in the regulation of IN-R alternative splicing, we have designed a hypoxia-induced splicing system that recapitulates the IN-R splicing seen in tumors. We have shown that sequence elements flanking the regulated exon are important for the hypoxia-induced splicing changes. Furthermore, have performed an antisense oligonucleotide (ASO) walk to target these splicing enhancer and repressor sequences to interfere with IN-R splicing. We have successfully targeted the CUGBP1 negative regulator of splicing that resides in intron 10 to increase the IN-R B full-length isoform. We have shown that an ASO used to drive production of the IN-R B isoform in a rhabdomyosarcoma (RMS) cell line, which normally expresses the IN-R A isoform, affects cancer cell behavior to induce reduced motility and cell migration. We therefore postulate that modulation of the splicing of the IN-R, alone or in conjunction with IGF-1R blocking antibodies, could be used as a therapeutic intervention in pediatric RMS cells.

Citation Format: Dawn S. Chandler, Chelsea Brown, Hemant Bid, Thomas Bebee, Daniel F. Comiskey, Frank Rigo, Peter J. Houghton. Targeting insulin receptor splicing as a therapeutic intervention for pediatric rhabdomyosarcoma. [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-014.
Abstract LB-018: Loss of function mutations of an ETS repressor expand the ETS positive subset of prostate cancer
Authors: Bose Rohit , Abida Wassim , Karthaus Wouter , Armenia Joshua , Iaquinta Phillip , Wongvipat John , Doran Michael , Hieronymus Haley , Watson Philip , Sullivan Patrick , Liang Yupu , Schultz Nikolaus , Sawyers Charles
Published: July 2016

Recent genomic profiling of both primary and metastatic prostate cancers has revealed novel loss-of-function point mutations and copy number deletions of the gene ERF, an ETS transcriptional repressor with a nearly identical DNA-binding domain to the TMPRSS2-ERG oncogene product. Furthermore, ERF homozygous loss or point mutations occur exclusive of the ERG upregulation that occurs in 50% of prostate cancers following fusion of androgen-regulated upstream genomic elements of TMPRSS2 to the ERG gene.

We characterized the function of ERF, as well as its relationship to ERG using CRISPR and shRNA technology to investigate both normal prostate- and patient tumor-derived organoid cultures, as well as existing TMPRSS2-ERG positive models. In both normal prostate and tumor models lacking upregulated ERG, inhibition of the ERF repressor leads to an expansion of the androgen transcriptome, and recapitulates phenotypic features seen with ERG upregulation. Cistromic analysis reveals that ERF occupies androgen-receptor (AR) associated chromatin, overlapping with potential ERG sites. Accordingly, in the presence of the upregulated ERG oncogene, ERF is now unable to bind any AR associated chromatin, and the AR transcriptome is expanded. CRISPR-mediated loss of ERG in TMPRSS2-ERG positive models leads to a halt of tumor cell growth, but concomitant loss of the ERF repressor partially restores cellular proliferation.

We conclude that ERF is an endogenous repressor of androgen signaling in normal prostatic tissue and a potential tumor suppressor in prostate cancer. It occupies chromatin associated with AR-regulated genes and inhibits their transcriptional regulation. Loss of ERF function, either by mutation or more frequently by competition with the TMPRSS2-ERG gene product, leads to an expansion of the androgen transcriptome. Thereby, the ETS positive subtype of prostate cancer, currently defined by an activating ETS fusion event (e.g. TMPRSS2-ERG) should be expanded to encompass genomic loss of a repressive ETS factor.

Citation Format: Rohit Bose, Wassim Abida, Wouter Karthaus, Joshua Armenia, Phillip Iaquinta, John Wongvipat, Michael Doran, Haley Hieronymus, Philip Watson, Patrick Sullivan, Yupu Liang, Nikolaus Schultz, Charles Sawyers. Loss of function mutations of an ETS repressor expand the ETS positive subset 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-018.
Abstract LB-028: CIRP promotes keratinocytes survival following low-dose UVB irradiation through Stat3-mediated Bag-1/S expression
Authors: Liao Yi , Tang Liling , Wu Shiyong
Published: July 2016

UV induces CIRP expression and subsequent Stat3 activation, but the biological function and mechanism of CIRP and Stat3 in mediating UVB-induced skin carcinogenesis have not been fully elucidated. In this study, we demonstrate that CIRP is elevated in all tested melanoma and non-melanoma skin cancer cell lines; and the expression of CIRP is upregulated in keratinocytes after being irradiated with relatively low dose (<5 mJ/cm2), but not high dose (50 mJ/cm2), UVB acutely and chronically. The increased expression of CIRP, either induced by UVB or through overexpression, leads to resistance of keratinocytes to UVB-induced growth arrest and death; and reduced expression of CIRP by RNA knockdown sensitizes keratinocyte cells to the low dose UVB irradiation. We also demonstrated that CIRP expression is required for the low dose UVB-induced Tyr705-phosphorylation, but not total amount, of Stat3. The p-Stat3 level is correlated with the expression levels of cyclin D1 and VEGF, two known downstream cell growth regulators of Stat3, as well as Bag-1/S, an apoptosis regulator. Inhibition of Stat3 DNA-binding activity by S3I-201 leads to a reduction of the p-Stat3 and Bag-1/S along with growth and survival of keratinocytes post-UVB; and the effect of S3I-201 on the UVB-irradiated cells can be partially inhibited by overexpression of CIRP or Bag-1/S. Furthermore, the overexpression of Bag-1/S can totally inhibit UVB-induced PARP cleavage and caspase 3 activation. The results presented above led us to propose that CIRP-p(705)-Stat3 cascade promotes cell proliferation and survival post-UVB via upregulating the expression of cyclin D1 and Bag-1/S respectively.

Citation Format: Yi Liao, Liling Tang, Shiyong Wu. CIRP promotes keratinocytes survival following low-dose UVB irradiation through Stat3-mediated Bag-1/S expression. [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-028.
Abstract LB-031: Generation of inducible oncogenic chromosomal translocations using CRISPR-Cas9 genomic editing
Authors: Spraggon Lee , Martelotto Luciano , Hmeljak Julija , Slotkin Emily , Wang Lu , Reis-Filho Jorge , Ladanyi Marc
Published: July 2016

Specific, reciprocal chromosomal translocations are found in numerous cancers, typically leading to the formation and expression of fusion genes with oncogenic properties. It has been demonstrated that by inducing double-stranded breaks (DSBs) in genomic DNA, using either zinc fingers nucleases (ZF), transcription activator-like effector nucleases (TALENs), or the CRISPR-Cas9 system, it is possible to faithfully recapitulate such chromosomal translocations in human cell lines.

A potential pitfall is that the induction of the chromosomal translocation generates a constitutively active oncogenic fusion product, which can be detrimental to cell growth or viability in certain heterologous cell types. To overcome these obstacles, we have combined homology directed repair (HDR) with CRISPR-Cas9 genome editing to generate conditionally inducible chromosomal translocations. As proof of principle, we have used this approach to engineer human cell lines to carry the molecular hallmark present in Ewing Sarcoma, the t(11;22)(q24;q12) translocation.

Our approach allows for the de novo generation and capture of the desired chromosomal translocation in the context of a conditional allele. Whole genome sequencing (WGS) and fluorescence in situ hybridization (FISH) confirmed the accuracy of our genomic editing approach, whilst analysis of mRNA and protein levels confirmed the selective inducibility and generation of biologically functional EWSR1-FLI1 fusion oncogene. Therefore, our approach establishes an innovative platform for constructing isogenic and conditionally inducible biologically relevant models for a variety of cancers driven by chromosomal translocations.

Citation Format: Lee Spraggon, Luciano Martelotto, Julija Hmeljak, Emily Slotkin, Lu Wang, Jorge Reis-Filho, Marc Ladanyi. Generation of inducible oncogenic chromosomal translocations using CRISPR-Cas9 genomic editing. [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-031.
Abstract LB-038: Constitutive activation of mTORC1 in endothelial cells leads to the development and progression of lymphangiosarcoma through VEGF autocrine signaling
Authors: Sun Shaogang , Chen Song , Liu Fei , Wu Haige , McHugh Jonathan , Bergin Ingrid , Gupta Anita , Adams Denise , Guan Jun-Lin
Published: July 2016

Angiosarcoma/ lymphangiosarcoma is a rare malignancy with poor prognosis, for which animal models with a defined molecular pathogenesis are lacking. Here, we generated a new mouse model with an inducible endothelial cell specific deletion of Tsc1 to examine the potential role of abnormal activation of mTORC1 signaling in lymphangiosarcoma. We found that loss of Tsc1 increased EC proliferation and retinal angiogenesis in neonates. In adult mice, Tsc1 deletion led to a spectrum of endothelial proliferative lesions, ranging from vascular malformations to vascular tumors. Studies using rapamycin indicated that sustained mTORC1 signaling is required for both the development and maintenance of lymphangiosarcomas. Further analysis showed increased VEGF expression through increased activity of HIF1α and c-Myc transcription factors in tumor cells, and that blockade of autocrine VEGF signaling decreased proliferation of these cells both in vitro and in vivo. Lastly, we found significant correlations between mTORC1 activation and expression of VEGF, HIF1α and c-Myc in human angiosarcoma samples. Together, these studies demonstrate critical mechanisms of aberrant mTORC1 activation in the development of lymphangiosarcoma, and validate Tsc1iΔEC mice as a valuable novel model of lymphangiosarcoma with known molecular underpinnings for further study.

Citation Format: Shaogang Sun, Song Chen, Fei Liu, Haige Wu, Jonathan McHugh, Ingrid Bergin, Anita Gupta, Denise Adams, Jun-Lin Guan. Constitutive activation of mTORC1 in endothelial cells leads to the development and progression of lymphangiosarcoma through VEGF autocrine signaling. [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-038.