bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1686: Glypican-3 (GPC3) induces a mesenchymal-epithelial transition in human breast cancer cells lines
Authors: Castillo Lilian F. , Tascon Rocio , Joffe Elisa Bal de Kier , Peters Giselle
Published: July 2016

Glypicans constitute a family of heparan sulphate proteoglycans which are linked to the extracellular surface of the plasma membrane through a glycosylphosphatidylinositol anchor. Since GPC3 has been linked to cancer, herein we generated and characterized a pre-clinical human breast cancer cell model to evaluate the role of GPC3 in human mammary tumor progression. GPC3 expression was blocked in MCF-7 cells (poorly-metastatic, GPC3 +) by siRNA (generating MCF-7-shGPC3 sublines), while it was overexpressed in MDA-MB231cells (metastatic, GPC3 -) by viral infection (producing MDA-MB231-GPC3 sublines).

We performed in vitro and in vivo characterization of this model. GPC3 silenced MCF-7 cells acquired F-actin stress fibers, enhanced their clonogenic ability (Colony number 130 -shGPC3 vs. 37 -sh Negative Control (NC)) as well as their migration (Wound coverage (%): 15 -shGPC3 vs. 2 -shNC), were less susceptible to cell death induction (Cell death (%): 21.6 -shGPC3 vs. 34 -shNC), diminished the expression of the epithelial marker E-Cadherin while acquired the mesenchymal marker N-Cadherin, and were more invasive and metastatic in vivo. These cells exhibited an upregulation of the EMT-transcription factor ZEB1, and the canonical Wnt/beta-Catenin signaling pathway was activated.

GPC3 overexpressing MDA-MB231 cells misplaced their fibroblast-like appearance as well as their F-actin stress fibers, repressed their clonogenicity (Colony number: 8 -GPC3 vs. 40 -vector) and migratory capacity (Wound coverage (%): 10 -GPC3 vs. 90 -vector), were more sensitive to death in starving condition (Cell death (%) 30 -GPC3 vs. 6.5 -vector), got the ability to form E-Cadherin dependent-spheroids, reexpressed E-Cadherin in cell-cell junctions and downregulated the mesenchymal markers N-Cadherin and vimentin, while were less invasive and metastatic in vivo. The expression of the E-Cadherin repressor ZEB1 was diminished, as well as the activity of the canonical Wnt/beta-Catenin signaling pathway. However, when canonical Wnt signaling was activated by LiCl, the expression of E-Cadherin did not change.

In summary, we present in vitro and in vivo experimental evidence supporting the hypothesis that GPC3 has a protective role of human breast cancer progression by inducing mesenchymal-epithelial transition (MET). The canonical Wnt/beta-Catenin signaling inhibition would not be required for MET process induced by GPC3.

Citation Format: Lilian F. Castillo, Rocio Tascon, Elisa Bal de Kier Joffe, Giselle Peters. Glypican-3 (GPC3) induces a mesenchymal-epithelial transition in human breast cancer cells lines. [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 1686.
Abstract 1703: Expression of Hedgehog signals and growth inhibition by itraconazole in endometrial cancer
Authors: Inoue Kayo , Tsubamoto Hiroshi , Shibahara Hiroaki , Tamura Kazuo
Published: July 2016

Background: There are limited therapeutic opportunities for the treatment of endometrial cancer (EC). Itraconazole, a common antifungal agent and a potent inhibitor of the Hedgehog pathway, has been shown to be clinically effective for various types of cancer, but its clinical efficacy for EC is unknown. Herein, we evaluated the efficacy of itraconazole in treating EC.

Patients and Methods: We reviewed cases of patients with serous endometrial intraepithelial carcinoma (SEIC) and patients who were diagnosed with EC with endometrioid adenocarcinoma grade 1 or 2 at FIGO stage IA with myometrial invasion and negative cytology of ascites and who recurred at our institution from January 2005 to December 2013. We also reviewed cases with endometrioid adenocarcinoma grade 1 or 2 at FIGO stage IA with myometrial invasion and negative cytology of ascites without recurrence over 5 years after surgery during 2006 and 2007. Immunohistochemistry was performed on EC tumour samples including SEIC for sonic Hedgehog (sHh), glioma-associated oncogene homolog 1 (GLI1), Progesterone receptor (PR), and chemokine ligand 18 (CCL18). Furthermore, we examined the effects of itraconazole on human EC cell lines (Ishikawa and HEC-1A cells) using a modified methylthiazol tetrazolium (MTT) assay and a migration assay.

Results: SHh and GLI1 were expressed in SEIC and endometrioid adenocarcinoma. Immunohistochemical evaluation of sHh and GLI1 did not distinguish between recurrent and non-recurrent low-grade FIGO stage IA EC. The MTT assay revealed that itraconazole significantly inhibited the growth of Ishikawa and HEC-1A cells in a dose-dependent and time-dependent manner. However, migration was not significantly effected for either Ishikawa or HEC-1A cells. HEC-1A cells exhibited dose-dependent migration retardation.

Conclusion: Hedgehog signalling plays a role in carcinogenesis and malignant progression in EC. Itraconazole at a physiological dose may suppress progression of EC.

Citation Format: Kayo Inoue, Hiroshi Tsubamoto, Hiroaki Shibahara, Kazuo Tamura. Expression of Hedgehog signals and growth inhibition by itraconazole 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 1703.
Abstract 1706: Evaluation of LGR5 protein expression in colon cancer stem cells
Authors: Fu Wei , Gonzalez Rachel , Yuan Kehu , Chen Caiwei , Wei Haitao , Lu Hsiangmin , Ren Qi , Logis Evelin , Kelly Sean , He Wei-Wu , Ma Donghui
Published: July 2016

Cancer stem cells are a subpopulation of cancer cells responsible for cancer initiation, development and metastasis. A number of studies demonstrated that Leucine-rich repeat containing G-protein-coupled receptor 5 (LGR5) can drive cancer development through triggering canonical Wnt signaling and its downstream gene expression. LGR5 is an important biomarker specifically expressed on colon cancer stem cells. In this study, we have successfully developed an LGR5 antibody with high specificity to detect endogenous LGR5 expression in different immunoassay application.

By screening multiple anti-LGR5 hybridoma clones, antibody generated by clone UMAB212 was proven to be highly specific on our high density protein microarray chip assay. Here our experimental data demonstrated that clone UMAB212 recognizes not only human LGR5 protein but also mouse LGR5 protein in both western blot and flow cytometry applications. No cross-reactivity was observed with the other two LGR family members, LGR4 and LGR6. Furthermore, this antibody also works great on immunohistochemistry application on FFPE tissue blocks. In summary, UMAB212 is great tool for us to study LGR5 protein in different immunoassay setting and it could also be a potential cancer diagnostic reagent.

Citation Format: Wei Fu, Rachel Gonzalez, Kehu Yuan, Caiwei Chen, Haitao Wei, Hsiangmin Lu, Qi Ren, Evelin Logis, Sean Kelly, Wei-Wu He, Donghui Ma. Evaluation of LGR5 protein expression in colon cancer stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1706.
Abstract 171: Comparative genomic analyses of synchronous colorectal cancers by exome sequencing
Authors: Hänninen Ulrika A. , Tanskanen Tomas , Katainen Riku , Böhm Jan , Taipale Minna , Taipale Jussi , Mecklin Jukka-Pekka , Mäkinen Netta , Aaltonen Lauri A.
Published: July 2016

Colorectal cancer (CRC) is the third most common cancer type and the second leading cause for cancer deaths in the Western world. Around 3.5% of CRC patients have more than one primary colorectal carcinoma at the time of diagnosis. These so-called synchronous colorectal cancers (SCRC) are more common in men and have been associated with predisposing conditions, such as hereditary nonpolyposis colorectal cancer (HNPCC), familial adenomatosis polyposis (FAP) and inflammatory bowel disease. Such conditions account for slightly more than 10% of SCRC cases. The pathological and clinical features of the tumors have been widely studied. The underlying molecular mechanisms in SCRC have not been well described, though. The research has mainly focused on single factors such as microsatellite instability (MSI) status or APC-, KRAS-, and p53-mutations.

By exome sequencing a tumor pair and corresponding normal sample from 23 patients, we aim to study the extent of genetic overlap between the synchronous tumors to assess if they derive from a common progenitor. The tumor data will be filtered against the normal tissue data to verify the somatic origin of the observed mutations. The comparison of the mutation profiles in each tumor pair will take into account the number of shared variants that occur in the exact same positions in the coding region. If the tumors share a high number of changes in exactly the same base it would suggest they have a common origin. Different mutation patterns, with possibly a few coincidental shared mutations, may support a stochastic process in the genesis of the two tumors. We will also identify commonly mutated genes - those that are mutated in both tumors of a synchronous pair or among synchronous pairs of different patients.

The patient material derives mainly from a consecutive, population-based colorectal cancer collection “Suolisyöpä Keski-Suomi 2000-2010” from Jyväskylä, Finland. In addition three SCRC-cases were included from our in-house collections. Knowledge on the molecular basis of SCRC, which haven't been studied to this extent before, provides insight on how these tumors arise and allows for development of more personalized treatments.

Citation Format: Ulrika A. Hänninen, Tomas Tanskanen, Riku Katainen, Jan Böhm, Minna Taipale, Jussi Taipale, Jukka-Pekka Mecklin, Netta Mäkinen, Lauri A. Aaltonen. Comparative genomic analyses of synchronous colorectal cancers by exome sequencing. [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 171.
Abstract 1710: Novel syngeneic mouse gastric cancer models identified Sca-1 as a gastric cancer stem cell marker
Authors: Park Jun Won , Kim Hark K.
Published: July 2016

Genetically well-defined syngeneic mouse models for gastric cancer are not available in the scientific community, but critical for the development of immunotherapeutic agents. We generated primary mouse gastric cancer cell line NCC-S1 (S1) established from a Villin-cre;Smad4F/F;Trp53F/F;Cdh1F/wt mouse and its metastatic variant cell line NCC-S1M (S1M). These cells closely recapitulated human diffuse type gastric cancers in histology and molecular profiles. S1M cells showed enhanced in vivo growth and metastatic potentials compared with S1 cells, and developed orthotopic and heterotopic tumors in immunocompetent mice in predictable manner. S1M allograft model was useful for testing the efficacy of an immunotherapeutic agent, anti-4-1BB. Sca-1 was overexpressed in S1M cells compared with S1 cells. Approximately 7% of gastric cancer cells in primary tumors expressed Sca-1. Sca-1high cells were more tumorigenic according to the in vivo limiting dilution assay, and more resistant to cisplatin and fluorouracil. Sca-1high cells overexpressed CD133, CD44, EPCAM and Bcl-xL. A chromatin immunoprecipitation analysis demonstrated that Sca-1 was a β-catenin/LEF1 target gene. Expression profiles of 85 genes overexpressed in Sca-1high S1 cells clustered 123 pretreatment gastric cancer patient samples according to the overall survival following cisplatin/fluorouracil chemotherapy. Thus, our novel metastatic gastric cancer cell lines are useful resources for drug development, and identified Sca-1 as a novel gastric cancer stem cell marker that mediates β-catenin signaling.

Citation Format: Jun Won Park, Hark K. Kim. Novel syngeneic mouse gastric cancer models identified Sca-1 as a gastric cancer stem cell marker. [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 1710.
Abstract 1717: Circulating tumor cells from in vitro 3D culture systems have tumor-initiating capacity in vivo
Authors: Cabrera Marina C. , Hurt Elaine , Chen Xiaoru , Xiaoqing Shi , Bao Haifeng
Published: July 2016

Circulating tumor cells (CTCs) are cells that have detached from the primary tumor and entered the bloodstream with the potential to seed metastatic tumors in distal sites. High CTC numbers correlate with aggressive disease, increased metastasis, and decreased time to relapse. It has also been shown that cancer stem cells (CSCs) represent a proportion of the CTCs present in patients. Given that CSCs are resistant to chemotherapy and are responsible for tumor initiation, it is posited that the CSCs are the seeds of metastasis. However, direct evidence for this hypothesis is limited because there are few methods for culturing and studying these rare cells. We are using a 3D culture chamber system (RealBio D4™) to establish long-term cultures of human-derived breast and pancreatic tumors. We observed that the system's 3D matrix supported culture development and incorporation of tissue organization and microenvironment. Further, the chamber design allowed CTCs generated within the cultures to migrate out of the cell mass into the circulating nutrient medium where they were collected for characterization. The isolated CTCs displayed CSC properties via CellSearch® (CD44+,CD24-; CD44+,CD24+ for breast and pancreas respectively). In addition, these isolated CTCs displayed tumor-initiating capacity when implanted into mice. Future studies will compare CTCs isolated from 3D culture with cells from tumors, blood, and tissue grown on scaffold through RT-PCR, histology, and gene expression assays.

Citation Format: Marina C. Cabrera, Elaine Hurt, Xiaoru Chen, Shi Xiaoqing, Haifeng Bao. Circulating tumor cells from in vitro 3D culture systems have tumor-initiating capacity 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 1717.
Abstract 172: Managing metastatic breast cancer via serial monitoring with circulating cell-free tumor DNA next generation sequencing testing
Authors: Austin Laura , Nagy Rebecca , Zill Oliver , Lanman Richard B. , Talasaz AmirAli , Cristofanilli Massimo
Published: July 2016

Background: Metastatic breast cancer (MBC) is an incurable disease with complex molecular features including somatic mutations that evolve in relation to genomic instability and selective treatment pressure. Patients with treatment-refractory MBC may benefit from tumor genomic evaluation using next generation sequencing (NGS). Furthermore, analysis of circulating tumor DNA (ctDNA) in patients with advanced disease offers the possibility of non-invasive molecular monitoring.

Methods: A patient with MBC was tested at each progression with a ctDNA NGS panel (Guardant360™) that includes all NCCN-recommended somatic genomic variants for solid tumors and sequences complete exons of >50 genes to report single nucleotide variants (SNVs), fusions, amplifications, and indels with high sensitivity and ultra-high specificity (>99.9999%). The patient was diagnosed with invasive breast cancer at age 44 and treated with surgery and hormonal therapy. At age 61, she had axillary adenopathy and liver metastases. Treatment details are in Table 1.

Results: ctDNA analysis was performed at the time of metastatic diagnosis and at 5 additional time points over the course of treatment. All samples revealed an ERBB2 exon 19 indel (p.Leu755_Glu757delinsSer), and multiple SNVs and gene amplifications. ERBB2 amplification was seen in 4 of 6 samples. Mutant allele fractions (Table 1) correlated with clinical response to treatment and progression.

Conclusions: Analysis of ctDNA in this patient identified an ERBB2 exon 19 indel, which are present in 2-4% of non-small cell lung cancers but 1-2% in breast cancer. Treatment with anti-HER2 monoclonal antibody or dual anti-EGFR/ERBB2 tyrosine kinase inhibitor therapies may show clinical benefit. ctDNA analysis can detect emergence of actionable resistance mutations with the advantage of serial evaluation, allowing capture of inter- and intra-tumor heterogeneity and illustration of molecular progression and response. Table 1.Blood DrawDisease status at time of blood drawMutant allele fraction of ERBB2 indel (* = ERBB2 amplification)Treatment1Initial diagnosis9%trastuzumab, pertuzumab and docetaxel (TPD), cycle 12Stable disease1%*TPD cycle 23Progressing10%*TPD cycle 34Progressing62%*trastuzumab, emtansine (TDM1) 3 cycles5Progressing70%*vinorelbine, trastuzumab, everolimus6Partial response1%flourouracil, epirubicin, cyclophoasphamide

Citation Format: Laura Austin, Rebecca Nagy, Oliver Zill, Richard B. Lanman, AmirAli Talasaz, Massimo Cristofanilli. Managing metastatic breast cancer via serial monitoring with circulating cell-free tumor DNA next generation sequencing testing. [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 172.
Abstract 1729: Withaferin A blocks formation of IFN-γ-induced metastatic cancer stem cells through inhibition of the CXCR4/CXCL12 pathway in the UP-LN1 carcinoma cell model
Authors: Chou Andy Shau-Bin , Ting Li-Lei , Hsieh Chin-Hsuan , Pang See-Tong , Liao Shuen-Kuei
Published: July 2016

As our understanding of cancer stem cell (CSC) biology improves, there is an urgent need to search for inhibitory agents of CSCs and metastatic CSCs (mCSCs) positive for CXCR4. Withaferin A (WA), a withanolide extracted from the medicinal plant Withania somnifera, has been shown to exhibit anti-cancer effects through multiple mechanisms. Whether WA could selectively target CSCs, mCSCs, or non-CSCs of a gastrointestinal (GI) carcinoma tumor remains unclear. Side population analysis, flow cytometric phenotyping and sorting, non-invasive imaging in conjunction with xenotransplantation, and immunohistology were used in this investigation. Using the lymph node metastatic GI cancer cell line UP-LN1, consisting of CD44high/CD24low grape-like floating (F) and CD44low/CD24high adherent (A) cell subsets, this study demonstrated that, as compared with parental UP-LN1 cells or A cells, WA preferentially reduced F-cell proliferation, tumor sphere formation, and side population cells in vitro in greater efficiencies by apoptosis. This action was mechanistically mediated via the down-regulation of CXCR4/CXCL12 and STAT3/IL-6 pathways, both of which are instrumental in the acquisition of metastatic ability. Attenuation of IFN-γ-induced CXCR4 expression in F cells by knockdown with siRNA or blocking with anti-CXCR4 antibody, followed by Western blot analysis, showed significantly reduced metastatic potential in vitro. The extent of in vitro anti-invasive effect of WA on the IFN-γ-treated F cells was significantly greater than on the F cells without WA treatment, or F cells treated with control siRNA or with control IgG antibody. The observed in vitro effects of WA on the CSC and mCSC targeting were validated by data obtained with non-invasive imaging in NOD/SCID mouse xenotransplantation. We conclude that WA could efficiently block the formation of both CSCs and mCSCs in the UP-LN1 cell line, suggesting that WA may be considered an effective therapeutic agent for GI malignancies exhibiting grape-like tumor sphere.

Citation Format: Andy Shau-Bin Chou, Li-Lei Ting, Chin-Hsuan Hsieh, See-Tong Pang, Shuen-Kuei Liao. Withaferin A blocks formation of IFN-γ-induced metastatic cancer stem cells through inhibition of the CXCR4/CXCL12 pathway in the UP-LN1 carcinoma cell model. [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 1729.
Abstract 1748: The relationship between nut consumption and risk of colorectal cancer
Authors: Lee Jeeyoo , Shin Aesun , Lee Jeonghee , Park Ji Won , Oh Jae Hwan , Kim Jeongseon
Published: July 2016

Introduction

Nuts consumption has been associated with reduced risk of obesity, diabetes mellitus, and cardiovascular diseases. However, the association between nuts and colorectal cancer risk remains unclear.

Objective

In this study, we aimed to investigate the relationship between nuts consumption and colorectal cancer risk in a case-control study.

Methods

A case-control study was conducted with 923 colorectal cancer patients and 1846 controls recruited from the National Cancer Center in Korea. Information on dietary intake was collected using a food frequency questionnaire (FFQ) with 106 items. Nuts consumption level was classified by sex-specific quartile of control group. Binary and polytomous logistic regression models were used to estimate odds ratios (OR) and their 95% confidence intervals (CI) for the association between nuts consumption and colorectal cancer risk.

Results

High nuts consumption was strongly associated with a reduced risk of colorectal cancer in women (OR, 0.18; 95% CI 0.10-0.32 for highest vs. lowest quartile) and similar inverse association was observed for men (OR, 0.36; 95% CI 0.25-0.52). In subsite analysis, adjusted ORs (95% (CI)) comparing the highest vs the lowest quartile of nuts consumption were: 0.49 (0.24-0.99) for proximal colon cancer, 0.38 (0.23-0.64) for distal colon cancer, and 0.29 (0.18-0.46) for rectal cancer in men. An inverse association was also found in women for proximal colon cancer (0.16 (0.05-0.51)), distal colon cancer (0.16 (0.07-0.37)) and rectal cancer (0.25 (0.12-0.51)).

Conclusion

We found a statistically significant association between higher nuts intake and reduced risk of colorectal cancer and the association was observed for all subsites of colorectum in both men and women.

Citation Format: Jeeyoo Lee, Aesun Shin, Jeonghee Lee, Ji Won Park, Jae Hwan Oh, Jeongseon Kim. The relationship between nut consumption and risk of colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1748.
Abstract 1763: Body size and incidence of TMPRSS2:ERG fusion-positive and fusion-negative prostate cancer
Authors: Ahearn Thomas , Graff Rebecca E. , Pettersson Andreas , Pernar Claire , Markt Sarah C. , Wilson Kathryn M. , Fiorentino Michelangelo , Loda Massimo , Giovannucci Edward L. , Mucci Lorelei A.
Published: July 2016

Background: Evidence suggests that genetic, lifestyle, and hormonal factors are differentially associated with the incidence of TMPRSS2:ERG fusion-positive and fusion-negative tumors, suggesting that these molecular subtypes have distinct etiologies. There is scant literature on whether anthropometrics are differentially associated the risk of developing fusion-positive and fusion-negative prostate cancer.

Methods: We examined the associations between adult height, recalled BMI at age 21, and updating BMI over time with risk of prostate cancer defined by TMPRSS2:ERG subtype using a prospective cohort of 49,372 men from the Health Professionals Follow-up Study. Tumor TMPRSS2:ERG status was assessed by ERG immunohistochemistry on tissue microarrays constructed from radical prostatectomy of the prostate specimens. We utilized multivariable competing risks models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of fusion-positive disease and, separately, fusion-negative disease.

Results: During 23 years of follow-up, we identified 5,847 total prostate cancer cases. Among them, 2,402 were treated with RP, of whom 913 (15.6% of all cases) were assayed for ERG status. Height (per 5 inches) was positively associated with the risk of developing ERG-positive prostate cancer (HR = 1.24, 95% CI 1.03-1.50), but not associated with ERG-negative disease (HR = 0.98, 95% CI = 0.82-1.18, Pheterogenity = 0.07). Updated BMI (per 5 kg/m2) was inversely associated with the risk of developing ERG-positive disease (HR = 0.86, 95% CI = 0.74-1.00), but not associated with ERG-negative disease (HR = 1.03, 95% CI = 0.90-1.18, Pheterogenity = 0.07). BMI at age 21 was not differentially associated with the risk of developing ERG-positive or ERG-negative disease.

Conclusion: Our results suggest that height and obesity are differentially associated with the risk of developing fusion-positive and fusion-negative prostate cancer.

Citation Format: Thomas Ahearn, Rebecca E. Graff, Andreas Pettersson, Claire Pernar, Sarah C. Markt, Kathryn M. Wilson, Michelangelo Fiorentino, Massimo Loda, Edward L. Giovannucci, Lorelei A. Mucci. Body size and incidence of TMPRSS2:ERG fusion-positive and fusion-negative 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 1763.
Abstract 1775: Differential expression of exosomes-associated onco-microRNAs in African Americans with prostate cancer
Authors: Moustafa Ahmed A. , Sholl Andrew B. , Tsumagari Koji , Hassan Mohamed , Kandil Emad , Abdel-Mageed Asim B. , Abd Elmageed Zakaria Y.
Published: July 2016

Background: The mortality rate of prostate cancer (PCa) is two times higher in African American (AA) than Caucasian American (CA) men. The molecular mechanisms underlying these health disparities among AA men have yet to be fully elucidated. Our study aimed to evaluate the role of exosomes-associated onco-microRNAs (miRs) as biological determinant for the racial disparity of PCa patients.

Methods: Exosomes were isolated from the conditioned medium of MDA-PCa-2b (AA-origin), PC-3 (CA origin), C4-2B and RWPE-1 (non-tumorigenic) cell lines to study the endogenous expression of a number of onco-miRs and their anticipated target genes using Real-Time PCR and Western blot analyses. The potential candidates were validated in exosomes procured from plasma of human AA PCa patients and their counterparts. Onco-miRs target genes such as Lats-2, PDCD4, and SMEK1 were validated on cellular and exosomes derived from cells and human specimens. Onco-miRs and their targets were correlated with age and Gleason score of the disease.

Results: Not only onco-miR-125b, miR-155, and miR-3613 were upregulated in PCa versus normal RWPE1 cells but also in AA versus CA PCa cells. Onc-miR-3613 and miR-3680 were 3-4 times upregulated in cells and in C4-2B-derived exosomes compared to RWPE-1-derived vesicles. Also, these miRs were upregulated (∼2.5 fold) in MDA-PCa-2b versus PC-3 cells. The expression of tumor suppressor genes, such as Lats2, PDCD4, and SMEK1, were downregulated in PCa cells compared to normal cells. Differential expression of PCa exosomes-associated onco-miRs was also demonstrated in AA PCa patients compared to CA PCa and their age-matched normal subjects. A positive correlation was found between onco-miR-125b and high Gleason score (r = 0.763, p<0.01).

Conclusion: Our findings underline the role of exosomes-associated onco-miRs in health disparity of PCa. The differential expression of onco-miRs and their tumor suppressor genes in AA men projects their potential role as prognostic markers and/or future therapeutic targets in the context of racial disparity.

Citation Format: Ahmed A. Moustafa, Andrew B. Sholl, Koji Tsumagari, Mohamed Hassan, Emad Kandil, Asim B. Abdel-Mageed, Zakaria Y. Abd Elmageed. Differential expression of exosomes-associated onco-microRNAs in African Americans with 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 1775.
Abstract 1781: Ethnic disparity in pediatric leukemia relapse
Authors: Gillespie Mirinda , Hale Greg , Amankwah Ernest K.
Published: July 2016

Background: Leukemia is the most prevalent pediatric malignancy, representing 25% of all cancer diagnoses among children. Despite recent substantial improvements in therapy that have dramatically increased survival, 10-20% of cases develop relapse and become refractory to treatment. Although racial/ethnic disparity in survival is well documented, limited knowledge currently exists on the disparity in relapse. The objective of this study was to compare the risk of pediatric leukemia relapse between Hispanic Whites and non-Hispanic Whites.

Methods: The study included children (<21 years) diagnosed with leukemia between January 2006 and December 2014 at the All Children's Hospital Johns Hopkins Medicine, St. Petersburg, FL. Patients’ demographic and clinical information were obtained from an electronic health record-derived data warehouse. Ethnicity was self-reported. Leukemia diagnosis and relapse were identified using appropriate ICD-9 codes. Relapse-free survival was defined as the time from diagnosis to the first documentation of relapse. Hazard ratios (HR) and 95% confidence intervals (95% CI) for relapse-free survival were calculated using Cox proportional hazard models adjusting for age at diagnosis, gender and type of insurance (commercial vs government).

Results: The study included 66 Hispanic Whites and 202 non-Hispanic Whites. The median age for both groups was 7 years. However compared to non-Hispanic Whites, Hispanic Whites were more likely to be males (59% vs 53%), to have government insurance (71% vs 35%) and had a shorter median follow up time (52 vs 66 months). Approximately 15% of Hispanic Whites developed relapse compared to only 5% non-Hispanic Whites. Kaplan-Meier survival analysis showed a difference in relapse between the two groups (log-rank p = 0.006). After adjusting for age at diagnosis, gender and type of insurance, Hispanic Whites were three times more likely to develop relapse compared to non-Hispanic Whites (HR = 3.1, 95%CI = 1.2-8.0, p = 0.02).

Conclusion: Although the findings of this study suggest that ethnic disparity in pediatric leukemia may exist, our findings are limited by the inability to control for potential confounders such as medication adherence, timing of diagnosis, white blood cells at diagnosis and minimal residual disease. Future studies should further investigate this racial/ethnic disparity.

Citation Format: Mirinda Gillespie, Greg Hale, Ernest K. Amankwah. Ethnic disparity in pediatric leukemia relapse. [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 1781.
Abstract 179: Atypical protein kinase C inhibition in prostate cancer cells: a study of ICA-1 and ACPD
Authors: Apostolatos Andre H.
Published: July 2016

Aggressive and metastatic prostate cancers are highly lethal tumors and are one of the leading causes of death among men. Certain prostate cancers are highly lethal tumors due to the emergence of therapy-resistant cancer cells. There is a gap in knowledge relating to which intracellular chemicals confer the emergence of therapy-resistant prostate cancer cells, which intracellular chemicals are responsible for prostate cancer survival and which chemicals regulate intracellular signaling pathways in prostate cancer. To address this critical problem, we investigated two drugs that act as inhibitors of atypical Protein Kinase C Iota. The objective of this study was to test the effectiveness of ACPD as an atypical PKC inhibitor and ICA-1 as an inhibitor of PKC iota. [The Inter. J. Biochem. & Cell Biol. 43:784-794(2011)] DU-145 and PC-3 prostate carcinoma cells and non-malignant prostate RWPE-1 cells were each cultivated in separate flasks. They were treated with drugs of interest for three consecutive days. The cells were counted before and after the treatments and a statistical analysis was performed. The cells were lysed and levels of PKC iota and PKC zeta were measured by Western blotting and immunoprecipitation. Our preliminary results show that treatment of DU-145 and PC-3 showed a statistically significant decrease in cells that was proportional to the concentration in both drugs. Treatment of the RWPE-1 cells showed no statistically significant change in population. The Western blotting showed both drugs decreased PKC iota. In conclusion ACPD and ICA1 are effective inhibitors of PKC iota and PKC zeta and consequently significantly reduced the neogenesis of the prostate DU-145 and PC-3 carcinoma cells while having negligible effect on the non-malignant prostate RWPE-1 cells.

Citation Format: Andre H. Apostolatos. Atypical protein kinase C inhibition in prostate cancer cells: a study of ICA-1 and ACPD. [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 179.
Abstract 1796: Metformin may function as an anti-cancer agent of pancreatic cancer via targeting RET signaling pathway
Authors: Tan Xiang-Lin , Yue Wen , Wang Tao , Carpizo Darren , Lin Yong , Zheng Xi , Yang Chung S. , Zhang Lanjing , Xu Qing , DiPaola Robert S.
Published: July 2016

Pancreatic cancer (PaCA) is one of the most lethal human cancers and is the fourth leading cause of cancer-related deaths in the United States. However, there are currently no established recommendations for prevention of PaCA using pharmacological agents. Metformin has recently gained attention as an anti-cancer drug and/or a chemoprevention agent because of its effects on inhibiting mTOR, lowering hyperinsulinemia, modulating inflammatory responses, and selectively killing cancer stem cells. However, the key underlying molecular mechanisms for the inhibitory effects of metformin on PaCA progression remain largely unknown. Using RNA sequencing followed by the confirmation of RT-PCR and Western blotting, we found that metformin significantly decreased the mRNA and protein levels of RET (REarranged during Transfection), a single-pass transmembrane receptor tyrosine kinase (RTK). RET and its ligand, glial cell-derived neurotrophic factor (GDNF), were strongly expressed in PaCA and correlated to invasion and worse survival after surgical resection. GDNF, as a chemoattractant for PaCA cells, can activate RET to induce tumor progression, migration and invasion in vitro and in vivo. We further observed that metformin significantly inhibited GDNF-induced migration and invasion of PANC-1 cells. These data indicate that targeting RET with metformin or the combination of metformin and RET inhibitors may be an attractive and novel strategy for the prevention and treatment of PaCA progression and metastasis. To elucidate the molecular mechanisms for the inhibitory effects of metformin on the growth and spread of PaCA in humans, further in vitro and in vivo studies are warranted to investigate how metformin modulates RET signaling to inhibit the progression and metastasis of PaCA. Such studies have potential clinical significance using metformin as adjuvant preventive and therapeutic options for PaCA prevention and treatment. [This work was supported by grants from the National Cancer Institute at the National Institutes of Health (K07CA190541 and P30CA072720) and the National Natural Science Foundation of China (Grant No.: 81470132)]

Citation Format: Xiang-Lin Tan, Wen Yue, Tao Wang, Darren Carpizo, Yong Lin, Xi Zheng, Chung S. Yang, Lanjing Zhang, Qing Xu, Robert S. DiPaola. Metformin may function as an anti-cancer agent of pancreatic cancer via targeting RET signaling pathway. [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 1796.
Abstract 1805: CYP3A4 regulation of androgen receptor signaling in ER+ breast cancer
Authors: Gorjala Priyatham , Goodman Jr Oscar , Mitra Ranjana
Published: July 2016

Purpose: Eighty percent of breast cancers that are estrogen receptor-positive (ER+) express AR. According to American Cancer Society, every two out of three women are ER+ and initially respond to estrogen-receptor targeted therapies but later almost 50% of breast cancers, despite the presence of ER, fail to respond. Acquired resistance to these therapies is common and portends a poor prognosis, frequently requiring the use of cytotoxic therapies. Our preliminary results indicate that endocrine-resistant tumors express higher levels of AR and may depend on AR for their growth. Hence AR targeted therapies may be appropriate for these resistant tumors. As we have recently demonstrated that CYP3A regulates androgen receptor signaling, we wish to ascertain the role of CYP3A in regulating AR in endocrine-resistant breast cancer.

Methods: The ER+ cell lines MCF7 and T47D were used to study the role of AR in breast cancer. To study endocrine resistance in breast cancer, tamoxifen resistant MCF7 and T47D lines were generated with recurrent treatment of IC90 dosage of tamoxifen over 6 months’ time period. Cell fractionation, western blotting and q-RTPCR techniques were used to study the role of AR. siRNA inhibition of CYP3A4, the isoform expressed in breast, was used to study its role in regulating AR in breast cancer.

Results: Our results indicate that both MCF7 and T47D express active AR, inducible by DHT and R1881. Similar to prostate cancer we also observe that AR in these lines is regulated by CYP3A4. Cell fractionation studies indicate that inhibition of CYP3A4 by siRNA results in reduced AR migration to the nucleus inhibiting its role as a transcription factor. Our results also indicate that tamoxifen resistant cell lines express increased levels of AR. Tamoxifen resistant cell lines respond to bicalutamide/enzalutamide with a lower IC50 value than the native cell lines, reflecting their AR dependence. The resistant cell lines also show increased AR nuclear migration with R1881 induction as compared to native breast cell lines.

Conclusions: Endocrine-resistant breast cancer is sensitive to antiandrogen therapy. CYP3A4 may play an important role in endocrine-resistant breast cancer by negatively regulating AR activity.

Citation Format: Priyatham Gorjala, Oscar Goodman Jr, Ranjana Mitra. CYP3A4 regulation of androgen receptor signaling in ER+ 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 1805.
Abstract 181: Constitutive IRAK1/4 kinase activation contributes to NF-kB activity and chemoresistance in pancreatic cancer
Authors: Zhang Daoxiang , Li Lin , Jiang Hongmei , Yu Jinsheng , Knolhoff Brett , Head Richard , Lockhart Albert C. , DeNardo David G. , Wang-Gillam Andrea , Ruzinova Marianna B. , Lim Kian-Huat
Published: July 2016

Constitutive activation of the NF-κb transcription factor is a major molecular mechanism that contributes to the aggressive behavior and treatment resistance of pancreatic cancer. Understanding the molecular mechanisms that activate NF-κB will provide novel therapeutic opportunities to improve the dismal outcome of pancreatic cancer patients. In the present study, we showed that the Interleukin-1 Receptor-Associated Kinases 1 and 4 (IRAK1 and IRAK4) are constitutively activated in a majority of pancreatic cancer cell lines and patients samples, and are major drivers of NF-κB activity. Notably, we found that constitutive phosphorylation of IRAK4 is associated with poor patient prognosis. Suppression of IRAK1 and IRAK4 with small molecule inhibitor or RNA-interference in pancreatic cancer cells significantly reduces NF-κB activity, three-dimensional growth, invasiveness, production of inflammatory, and augment their sensitivity to chemotherapeutic agents in vitro. Notably, we showed that the NF-κB activity of pancreatic cancer cell with IRAK4 ablated using CRISPR technology can be restored with wild-type, but not kinase-dead IRAK4 mutant, supporting development of IRAK4 inhibitor as a novel therapeutic agent in pancreatic cancer. Silencing of IRAK1 or IRAK4, and more potently both, significantly abrogated the tumorigenic potential of human and murine pancreatic cancer cells as xenograft in mice. Lastly, we showed that IRAK1/4 inhibitor augments the therapeutic effect of gemcitabine in tumor-bearing mice by suppressing proliferation and increasing apoptosis of neoplastic cells, and reducing stromal fibrosis. Together, our data established IRAK4 kinase inhibitors as a promising novel class of targeted agent in pancreatic cancer.

Citation Format: Daoxiang Zhang, Lin Li, Hongmei Jiang, Jinsheng Yu, Brett Knolhoff, Richard Head, Albert C. Lockhart, David G. DeNardo, Andrea Wang-Gillam, Marianna B. Ruzinova, Kian-Huat Lim. Constitutive IRAK1/4 kinase activation contributes to NF-kB activity and chemoresistance in pancreatic 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 181.
Abstract 1810: Heterogeneous activation of PP-1 and Akt determines AR-v7 protein expression in prostate cancer cells under AR inhibition
Authors: Li Yinan , Xie Ning , Gleave Martin E. , Rennie Paul , Dong Xuesen
Published: July 2016

Background: Blocking the androgen receptor (AR) signaling is the first- and second-line treatment for metastatic prostate cancers. Although the newly developed AR pathway inhibitor (ARPI) improves patient survival, tumors invariably recurs and are most often driven by reactivation of the AR signaling. Enhanced expression of the AR splice variant, AR-v7, had been demonstrated to be one of the key mechanisms that confer prostate tumors with therapy resistance. However, molecular mechanisms by which control AR-v7 protein expression remain unclear.

Experimental Design: Multiple prostate cancer lines were challenged with androgen depletion and/or Enzalutamide treatment. Protein phosphatase-1 (PP-1) and Akt kinase activation were measured. AR and AR-v7 serine phosphorylation, ubiquitination, protein degradation as well as subcellular localization were determined.

Results: Enzalutamide induces differential activation of protein phosphatase-1 (PP-1) and Akt kinase depending on the genetic background of prostate cancer cell lines. PP-1 activation prevents AR-v7 from serine213 phosphorylation, Mdm2-mediated ubiquitination modification, cytoplasmic localization and proteasomal protein degradation. By contrast, Akt activation functions in the opposite to PP-1 and stimulates AR-v7 degradation. Therefore, the balance of PP-1 and Akt activations under ARPI treatment determines AR-v7 protein expression in prostate cancer cells.

Conclusion: Our studies highlight the decisive roles of PP-1 and Akt for AR-v7 protein expression and activities when AR is functionally blocked. It also provides an explanation on heterogeneous AR-v7 protein expression in prostate tumor biopsies.

Citation Format: Yinan Li, Ning Xie, Martin E. Gleave, Paul Rennie, Xuesen Dong. Heterogeneous activation of PP-1 and Akt determines AR-v7 protein expression in prostate cancer cells under AR inhibition. [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 1810.
Abstract 1825: ONC201 induces cell death in androgen receptor positive prostate cancer cells and shows synergistic effect with anti-prostate cancer drugs
Authors: Lev Avital , Lulla Amriti R. , Dicker David T. , El-Deiry Wafik S.
Published: July 2016

Prostate cancer is the most common cancer and the second leading cause of cancer related death among men in the United States. Current therapy for advanced prostate cancer is mainly based on androgen deprivation, though in many cases tumors become androgen-independent and resistant to available treatments. Thus, accessing novel therapies for prostate cancer and resistant tumors remains an important goal in the field. ONC201 is a first-in-class small molecule anti-cancer drug, shown to selectively induce cell death in most cancer cells tested in contrast to matched normal cells. In this study we investigated the single-agent and combination efficacy of ONC201 on a panel of prostate cancer cell lines with varied androgen receptor (AR) and receptor tyrosine kinases (RTKs) expression status. Our preliminary data suggests that the pro-apoptotic effects of ONC201 correlate with expression of androgen receptor and other receptor tyrosine kinases (RTKs). Specifically, high AR and low RTK (c-MET, EGFR, HER2 and IGFR) expression demonstrated higher sensitivity to ONC201 as compared to low AR and high RTK expression as evaluated by cell viability using the Cell-Titer Glo assay. We further modeled these findings in ONC201-sensitive 22Rv1 and ONC201-resistant DU145 cell lines. ONC201 induced robust apoptosis (cleaved PARP) in ONC201-sensitive 22Rv1 cells as compared to ONC201-resistant DU145 cells In addition, ONC201-sensitive 22RV1 cells showed abrogation of total AR expression 72 hours following treatment with ONC201. Thus, AR and RTK status seem to be emerging efficacy markers for response of ONC201 in prostate cancer cells. We are further investigating the involvement of ONC201 in the signal transduction pathway of AR and other RTKs in prostate cancer. Lastly, our initial screening for treatment of cells with a combination of ONC201 and FDA-approved therapies for prostate cancer showed synergistic potential of ONC201 with everolimus and docetaxel in both AR-dependent and independent cells. As expected, synergism of anti-androgen MDV3100 (enzalutamide) with ONC201 was restricted to AR positive prostate cancer cell lines. Our results indicate that ONC201 has therapeutic potential both as a single agent and in combination therapy for prostate cancer. Our long-term goal is to integrate our pre-clinical studies and translate the findings to single agent/combination trials of ONC201 for prostate cancer patients.

Citation Format: Avital Lev, Amriti R. Lulla, David T. Dicker, Wafik S. El-Deiry. ONC201 induces cell death in androgen receptor positive prostate cancer cells and shows synergistic effect with anti-prostate cancer drugs. [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 1825.