bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-152: Macrophage control of cancer cell stemness and tumor metastasis
Authors: Gorjestani Sara
Published: May 2015

A characteristic feature of cancer is the presence of an abundant inflammatory infiltrate, which includes tumor-associated macrophages. In response to diverse tumor-derived chemoattractants, macrophages invade the tumor microenvironment, promoting angiogenesis, growth, immunosuppression and metastasis. Because they stimulate tumor progression and metastasis, it is possible that tumor-associated macrophages enhance cancer initiating cell populations leading to increased tumorigenicity and metastasis. In the tumor microenvironment, macrophages are characterized into having two phenotypes, classical (M1) or alternative (M2). M2 macrophages suppress T-cell activation and promote angiogenesis and tumor progression, while M1 macrophages produce immunostimulatory cytokines and stimulate T cell mediated anti-tumor immunity. Whether and how macrophages affect cancer cell stemness and metastasis is not well understood. Recently our lab showed that suppression of PI3Kinase-gamma signaling in myeloid cells leads to a reduction in tumor growth, angiogenesis, and metastasis. Genetic or pharmaceutical blockade of PI3Kinase-gamma or its target alpha4beta1 integrin inhibits the trafficking of monocytes to tumors and blocks expression of M2 macrophage factors, such as TGF-beta, Arginase and IL-6. To discover how PI3Kinase-gamma regulates the macrophage phenotype we performed RNA sequencing (RNA-seq) of classical and alternative polarization conditions in PI3Kinase-gamma-deficient and WT macrophages. Using this approach, we identified gene clusters associated with tumor immunity and metastasis that are regulated by PI3Kinase-gamma. Furthermore, we observed that macrophages polarized to the M2 phenotype enhanced the colony formation of breast and lung cancer cell lines in an anchorage independent tumor spheroid outgrowth assay whereas M1 polarization inhibited colony formation. Taken together, our data support the hypotheses that PI3Kinase-gamma expressing M2 macrophages promote cancer cell stemness and tumor metastasis. These studies could lead to new approaches for cancer therapy by encouraging the use of PI3Kinase-gamma antagonists as adjuvants for immunotherapy of human cancer.

Citation Format: Sara Gorjestani. Macrophage control of cancer cell stemness and tumor metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-152. doi:10.1158/1538-7445.AM2014-LB-152
Abstract LB-156: A diet-derived sialic acid promotes inflammation and hepatocellular cancer
Authors: Samraj Annie N. , Laubli Heinz , Pearce Oliver , Secrest Patrick , Garcia-Bingman Andrea E. , Varki Nissi , Varki Ajit
Published: May 2015

N-glycolylneuraminic acid (Neu5Gc) is a non-human sialic acid derived from the diet (primarily red meat) that can be metabolically incorporated into human tissues despite being an antigen. Since this incorporation occurs in the face of circulating anti-Neu5Gc antibodies, we hypothesized that this generates an antibody-antigen reaction and leads to inflammation termed “xenosialitis”. Although red meat consumption is prominently associated with cancer development, pathological mechanisms behind this link are yet to be conclusively proven. The purpose of our research is to investigate the relationship between “xenosialitis”, inflammation and cancer. We used a Cmah null mouse model (mimicking the human lack of Neu5Gc) to provide evidence for such inflammation and cancer promotion. Anti-Neu5Gc antibodies were generated by immunizing Cmah null mice, with chimpanzee red blood cell membranes, or with human red blood cell membranes as controls. Pooled immune or control sera were repeatedly adsorbed with human red blood cells, and the resulting polyclonal antisera passively transferred into additional Cmah null mice that were on a diet with or without Neu5Gc. Mice fed with Neu5Gc and injected with anti-Neu5Gc antibodies showed dose-dependent elevation in acute phase proteins (Serum Amyloid A and Haptoglobin) in the serum as compared to controls. Such C57BL/6 mice are prone to developing hepatic adenomas and occasional carcinomas. Cmah null but not wild-type C57BL/6 mice immunized with chimpanzee red blood cell membranes and fed with Neu5Gc developed a higher frequency of hepatocellular cancer and liver histology showed Neu5Gc accumulation and foci of inflammation. In conclusion, Neu5Gc that has metabolically incorporated into tissues from the diet interacts with anti-Neu5Gc antibodies, generating xenosialitis. Potential correlations of human anti-Neu5Gc antibody levels with red meat consumption and cancer risk are being investigated. Methods to flush out the xenogenic Neu5Gc are being pursued. Similar mechanisms may be operative in other chronic inflammatory processes in diseases epidemiologically associated with red meat consumption, such as atherosclerosis.

Citation Format: Annie N. Samraj, Heinz Laubli, Oliver Pearce, Patrick Secrest, Andrea E. Garcia-Bingman, Nissi Varki, Ajit Varki. A diet-derived sialic acid promotes inflammation and hepatocellular cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-156. doi:10.1158/1538-7445.AM2014-LB-156
Abstract LB-173: Early detection of pancreatic cancer using a new 5-gene classifier
Authors: Bhasin Manoj , Bullock Andrea , Gu Xuesong , Bucur Octavian , Najarian Robert , Haines Jon Cody , Ruping Karl , Miksad Rebecca , Libermann Towia , Khosravi-Far Roya
Published: May 2015

Background: Largely due to late diagnosis when curative resection is no longer possible, Pancreatic Adenocarcinoma (PDAC) is a devastating disease marked by a mortality rate nearly equivalent to its incidence rate. While serum CA19-9 is associated with PDAC, it lacks the sensitivity and specificity needed for early and accurate diagnosis. Thus, early diagnosis of PDAC is critical to improving survival for PDAC patients and for accurate PDAC risk stratification.

Methods: We have identified key PDAC biomarkers through an optimized meta-analysis strategy of raw data (training sets). From this analysis, the top ranking genes that distinguish PDAC from normal pancreas were selected through statistical significance comparison of the consistency in differential PDAC gene expression across studies. The biomarker panel with the highest sensitivity and specificity in the training sets was chosen for assessment of predictive power in nine independent validation datasets. For a subset of genes in the panel, immunohistochemistry (IHC) analysis was performed in human PDAC and pancreatitis to validate our panel.

Results and Conclusions: We have identified a 5-gene classifier panel with specificity of 88.9% and sensitivity of 100% with an overall accuracy of 93.3% and AUC of 0.94 for discriminating PDAC from non-malignant (normal or pancreatitis) tissue. IHC analysis of two of the proteins confirmed enhanced expression in PDAC cells. Cell-based experiments demonstrated that both proteins enhance migration and invasion of PDAC cells as well as soft agar growth indicating that they may be causative in PDAC. The 5-gene predictor discriminated PDAC from healthy controls, as well as pancreatitis, with highest accuracy in nine independent validation sets. Our identified PDAC panel may facilitate early diagnosis and improve risk-stratification.

Citation Format: Manoj Bhasin, Andrea Bullock, Xuesong Gu, Octavian Bucur, Robert Najarian, Jon Cody Haines, Karl Ruping, Rebecca Miksad, Towia Libermann, Roya Khosravi-Far. Early detection of pancreatic cancer using a new 5-gene classifier. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-173. doi:10.1158/1538-7445.AM2014-LB-173
Abstract LB-18: Bcl2-associated athanogene 3 and major vault protein regulate cell survival and resistance to apoptosis in senescent cells by regulating ERK activation
Authors: Pasillas Martina , Shields Sarah , Reilly Rebecca , Mulrane Laoighse , Strnadnel Jan , Jirstrom Karin , Connor Darran O , Gallagher William , Gonias Steven , Coppinger Judith
Published: May 2015

Senescence is a prominent solid tumor response to therapy in which cells avoid apoptosis and instead enter into prolonged cell cycle arrest. We applied a quantitative proteomics screen to identify signals that lead to therapy-induced senescence (TIS) and discovered that Bcl2-associated athanogene 3 (Bag3) is upregulated after adriamycin treatment in MCF7 cells. Bag3 protein is a member of the BAG family of co-chaperones that interacts with Hsp70. Bag3 also regulates major signaling pathways. Mass Spectrometry analysis of the Bag3 Complex revealed a novel interaction between Bag3 and Major Vault Protein (MVP). Silencing of Bag3 or MVP shifts the cellular response to adriamycin in favor apoptosis. We demonstrate that Bag3 and MVP contribute to apoptosis resistance in TIS by activation of extracellular signal-regulated kinase1/2 (ERK1/2). Bag3 and MVP were required for ERK1/2 activation in response to adriamycin and silencing either gene product decreased cell survival in response to the drug. An increase in nuclear accumulation of MVP is observed during TIS and the shift in MVP subcellular localization is Bag3-dependent. We propose a model in which Bag3 binds to MVP and facilitates MVP accumulation in the nucleus, which sustains ERK1/2 activation. We demonstrate that Bag3 and MVP are expressed in a panel of diverse breast cancer cell lines and human tumor samples from patients. Silencing of Bag3 and MVP shifts the response to apoptosis and regulates ERK1/2 signaling in ER positive MCF7, ZR751 cell lines and triple negative MDA-MB-231 and MDA-MB-468 cells. Overall this study highlights Bag3-MVP as an important complex that regulates a potent pro-survival signaling pathway in breast cancer.

Citation Format: Martina Pasillas, Sarah Shields, Rebecca Reilly, Laoighse Mulrane, Jan Strnadnel, Karin Jirstrom, Darran O Connor, William Gallagher, Steven Gonias, Judith Coppinger. Bcl2-associated athanogene 3 and major vault protein regulate cell survival and resistance to apoptosis in senescent cells by regulating ERK activation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-18. doi:10.1158/1538-7445.AM2014-LB-18
Abstract LB-205: Genome-wide copy number analysis of pediatric hepatocellular carcinomas: Identification of characteristic aberrations
Authors: Pietsch Torsten , Carmichael A. , Vokuhl Christian , Leuschner Ivo
Published: May 2015

Hepatocellular carcinomas (HCC) of childhood are rare neoplams. Their pathogenesis is believed to be different from HCC in adulthood. The differential diagnosis from hepatoblastoma (HBL)is important because of worse prognosis of pediatric HCC (pHCC) and different treatment approaches. However, the diagnosis by conventional histological analysis may be difficult in some cases. Informations on chromosomal alterations in pHCC are lacking.

The aim of this study was to identify recurrent chromosomal aberrations in a larger cohort of pHCC and compare it to a previously published cohort of HBL (Weber et al., American Journal of Pathology, 2000) to identify characteristic chromosomal alterations of pHCC. Genomic DNA was extracted from FFPE samples of a cohort of 34 pHCC including 4 cases of the fibrolamellar subtype and 3 cases with partial fibrolamellar differentiation from the archives of the German Pediatric Tumor Registry, University of Kiel. Genome-wide copy analysis was performed by molecular inversion profiling. GISTIC analysis was done to identify significant large and focal aberrations.

Most frequent copy number alterations were gains of chromosome 1q (65%), 2q (35%), 6p (35%), 20 (35%), 19q (32%) and 8q (29%) and losses of chromosomal regions 1p (56%) and 4q (38%). In addition, GISTIC analysis identified several significant fokal alterations including losses of the AXIN1 tumor suppressor locus on 15q26 in 53% of cases. 6/34 pHCC lacked any larger chromosomal imbalances. Of note, 5 of these 6 genomically stable tumors showed fibrolamellar differentiation. When pHCC with fibrolamellar differentiation were compared to the other pHCC, loss of 1p and 4q and gains of 1q, 2q, 6q and 20 occurred significantly more frequent in the latter. When pHCC were compared to HBL, both entities shared similar alterations including gains if 1q and 2q, but losses of 1p (56% vs. 3%), and gains of 6p (35% vs. 3%) and 19q (32% vs. 0%) were significantly more frequent in pHCC.

In this genome-wide copy number analysis of a large cohort of pHCC we were able to identify for the first time characteristic alterations which may indicate a specific pathogenesis of these neoplasms, may help to subclassify pHCC and to differentiate these tumors from HBL.

Supported by the German Childhood Cancer Foundation.

Citation Format: Torsten Pietsch, A. Carmichael, Christian Vokuhl, Ivo Leuschner. Genome-wide copy number analysis of pediatric hepatocellular carcinomas: Identification of characteristic aberrations. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-205. doi:10.1158/1538-7445.AM2014-LB-205
Abstract LB-215: The TAM family of receptor tyrosine kinases play a role in acquired resistance to cetuximab
Authors: Brand Toni Michel , Iida Mari , Corrigan Kelsey L. , Luthar Neha , Hornung Megan , Toulany Mahmoud , Gill Parkash , Salgia Ravi , Wheeler Deric L.
Published: May 2015

Cetuximab is an anti-epidermal growth factor receptor (EGFR) monoclonal antibody that has shown efficacy in metastatic colorectal cancer, head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC). Clinical data suggests that patients whom initially respond to cetuximab eventually acquire resistance, highlighting the importance of understanding resistant mechanisms for the development of better treatment regimes for cancer patients. Recent studies have identified a role for the TAM family of receptor tyrosine kinases (Tyro, Axl, and Mer) in tumor biology, and more specifically the Axl receptor as playing a key role in promoting tumor growth and metastasis. In the current study, we utilized NSCLC and HNSCC models of acquired resistance to cetuximab and found that Axl was overexpressed, activated, and highly associated with EGFR as compared parental controls. Further, using siRNA technology and novel Axl targeting agents (antibody and tyrosine kinase inhibitor), Axl was found to regulate proliferation, EGFR activation, and MAPK signaling in cetuximab resistant clones (CtxR). Additionally, Axl mRNA expression was regulated by EGFR induced MAPK activation in resistant cells. To investigate the role of Axl in in vivo models of acquired resistance to cetuximab, de novo acquired resistance was created by prolonged treatment of cetuximab sensitive (CtxS) tumor xenografts with cetuximab. Analysis of resultant CtxR tumors demonstrated that Axl was hyperactivated and highly associated with EGFR as compared to vehicle treated tumors. In addition, CtxR tumors expressing the highest levels of phosphorylated Axl also expressed hyperactivated EGFR, supporting the role of Axl in EGFR activation. Finally, to expand these findings to other members of the TAM family, Tyro, Axl, or Mer were stably overexpressed in CtxS parental NSCLC cells and tested for cetuximab response. The results of this experimentation indicated that stable overexpression of each TAM receptor rendered CtxS cells resistant to cetuximab therapy. Collectively, the studies presented herein identify the TAM family of receptors as key players in acquired resistance to cetuximab and provide rationale for the clinical evaluation of anti-TAM receptor therapeutics in the resistant setting.

Citation Format: Toni Michel Brand, Mari Iida, Kelsey L. Corrigan, Neha Luthar, Megan Hornung, Mahmoud Toulany, Parkash Gill, Ravi Salgia, Deric L. Wheeler. The TAM family of receptor tyrosine kinases play a role in acquired resistance to cetuximab. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-215. doi:10.1158/1538-7445.AM2014-LB-215
Abstract LB-217: CK2 protein kinase promotes resistance to MAPK pathway inhibition
Authors: Zhou Bingying , Kassner Michelle , Yin Holly , Der Channing J. , Cox Adrienne D.
Published: May 2015

Small molecule kinase inhibitors have opened potential new avenues for treating cancers dependent on the RAS-RAF-MEK-ERK MAPK pathway, yet identification of both de novo/innate/intrinsic and acquired resistance mechanisms will be critical for the successful application of these inhibitors in the clinic. We interrogated the kinome to identify resistance mechanisms towards the novel ERK1/2-selective inhibitor SCH772984. We first utilized a kinome-focused RNAi screen to identify genes that, when silenced, sensitized KRAS-dependent pancreatic cancer cells to SCH772984. In our drug dose-response screen of 711 kinases (QIAGEN library), we used 4 independent siRNA duplexes to knock down each gene, treated at 5 different drug doses, then evaluated viability with a standard CellTiter-Glo assay. Nineteen kinases enhanced sensitivity to SCH772984 (where at least 2 siRNAs for each target decreased IC50) at least 5-fold, indicating that they could drive ERK1/2 inhibitor resistance. Among these were 4 of the 9 protein kinases (Cot, Raf-1, PAK3 and PRKCH) identified in a cDNA expression screen for kinases that caused resistance of BRAF-mutant melanoma to the BRAF inhibitor vemurafenib. We therefore hypothesized that at least some of the kinases that scored positive in this screen might be conserved both across the MAPK pathway and across different cancer types. The tetrameric protein kinase CK2 (formerly casein kinase II) has crucial roles in cell survival, proliferation and differentiation, and its expression and/or activity is dysregulated in cancers including melanoma. In very recent studies, we have now determined that the alpha subunit of CK2 is sufficient to cause resistance to each of the three ERK MAPK pathway inhibitors currently approved for treatment of melanoma: vemurafenib (BRAFi), dabrafenib (BRAFi) and trametinib (MEKi). Co-inhibition of the MAPK pathway and CK2 (e.g., with CX-4945, currently in phase I trials) further enhanced sensitivity. Thus, this combination may offer an effective regimen to forestall or delay tumor relapse. We also observed that CK2alpha maintains ERK phosphorylation in the presence of MAPK inhibitors, and that it posttranslationally reduces abundance of the ERK phosphatase DUSP6/MKP-3, in a kinase-dependent manner. The relationship of these findings to CK2-mediated mechanisms of drug resistance will be discussed.

Citation Format: Bingying Zhou, Michelle Kassner, Holly Yin, Channing J. Der, Adrienne D. Cox. CK2 protein kinase promotes resistance to MAPK pathway inhibition. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-217. doi:10.1158/1538-7445.AM2014-LB-217
Abstract LB-238: Antitumor activity of mini-IGFBP-3, a protease-resistant derivative of human IGF binding protein-3
Authors: Godeau François , Leneuve Patricia , Costa Laetitia D. , Bouc Yves L. , Renoir Jack-Michel
Published: May 2015

Insulin-like growth factors (IGF) are polypeptide hormones with potent anabolic and mitogenic properties that regulate cell growth and differentiation. Dysregulation of the IGF axis has been well documented in the development and progression of multiple types of cancer. Consequently, targeting the IGF axis has become an area of intense preclinical and clinical research through the development of 3 major classes of therapeutic compounds: antibodies that target IGF-IR, dual IGF-IR and IR tyrosine kinase inhibitors (TKI), and IGF ligands (IGF-I and IGF-II) neutralizing antibodies.

Due to their high affinities for IGF-I and IGF-II, six IGFBPs regulate IGF bioavailability and IGFBP-3 is the main carrier of circulating IGFs in postnatal serum. In order to efficiently neutralize the excess of free IGF ligand maintaining tumor progression, we have produced, using the baculovirus insect cell system, a protease-resistant mutein of human IGFBP-3 with conserved affinities towards both IGF-I and IGF-II that was fused to the human IgG1 Fc fragment. In vitro, the resulting immunoadhesin (mIGFBP-3-Fc), evaluated in both regular and 3D culture, was found to block proliferation, arrest cell cycle and induce apoptosis in various types of cancer cell lines (Colon Adenocarcinoma, Ewing's Sarcoma, Adrenocortical Carcinoma and Multiple Myeloma (MM). mIGFBP-3-Fc antitumor activity was evaluated in vivo using RPMI-8226 luciferase-expressing MM cells xenografts. When MM cells were grafted subcutaneouly, daily mIGFBP-3-Fc injections drastically reduced tumor growth and induced tumor cell apoptosis. Similarly, after iv tumor cell injection, bone marrow localization of MM cells was substantially reduced in the mIGFBP-3-Fc-treated group. Furthermore, when used in association with the proteasome inhibitor Bortezomib, mIGFBP-3-Fc was shown to enhance the antitumor effect of Bortezomib used as single agent. Altogether, these data support the concept that mIGFBP-3-Fc could improve MM treatment either as a single agent or in association with proteasome inhibitors.

Citation Format: François Godeau, Patricia Leneuve, Laetitia Da Costa, Yves Le Bouc, Jack-Michel Renoir. Antitumor activity of mini-IGFBP-3, a protease-resistant derivative of human IGF binding protein-3. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-238. doi:10.1158/1538-7445.AM2014-LB-238
Abstract LB-247: Circulating proteolytic products of tumor-resident enzyme as potential biomarkers for early detection of breast cancer
Authors: Hu Ye
Published: May 2015

In theory, any or all of tumor-secreted proteins can serve as cancer biomarkers. However, the reality is challenging to monitor because of the large degree of fluctuation in abundance and localization of these tumor-secreted proteins, especially in the early stage of tumor development and/or metastasis. As such, it seems feasible that we might take advantage of the fact that secreted proteases/peptidases in the tumor microenvironment generate proteolytic products, also referred to as “circulating peptides”, which are detectable in bloodstream and provide ample information about the body, “coded” in the patterns and quantity of these peptides. Herein we clearly link the catalytic activity of Carboxypeptidase N (CPN) to its proteolytic products during breast tumor progression in mouse model and clinical samples. CPN plays important roles in regulating vasoactive peptide hormones, growth factors, and cytokines by specifically cleaving their C-terminal basic residues. Circulating fragment profiling, by an approach combining nanopore fractionation and mass spectrometry, revealed the nature and extent of cleavage by CPN. These results correlated with the level of CPN-catalyzed peptides in blood taken from the tumor-bearing mice, healthy women and breast cancer patients. We showed that generation of C3f_R1310-L1319 specifically correlated with the CPN expression level. In both mouse and clinical patient samples, the amount of CPN was increased in tumor tissues compared to that seen in normal breast tissue, while its counterpart in blood remained constant. The amount of 6 CPN-catalyzed peptides predominantly increased in sera taken from both the mice at 2 weeks after orthotropic implantation and the patients’ plasma as early as the first pathologic stage of breast cancer. In conclusion, the circulating level of the selected 6 CPN-catalyzed proteolytic products reflects the extent of this enzyme's activity in tumors, and our results clearly indicate their strong potential as biomarkers for non-invasive early diagnosis of breast cancer.

Citation Format: Ye Hu. Circulating proteolytic products of tumor-resident enzyme as potential biomarkers for early detection of breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-247. doi:10.1158/1538-7445.AM2014-LB-247
Abstract LB-257: Immunoadjuvant ISG15 enhances human papillomavirus 16 antigen-specific cell-mediated antitumor immunity
Authors: Villarreal Daniel , Wise Megan C. , Yang Jian , Weiner David B.
Published: May 2015

Adjuvants are critical components of most clinically used vaccines and act as substances to enhance adaptive immune responses to an antigen. Here we examine a new immunoadjuvant, interferon stimulated gene 15 (ISG15), for its adjuvant effects in an HPV-associated cancer immune therapy model where cell-mediated immunity is crucial for protection. ISG15 is an ubiquitin-like protein induced by type I interferon and associated with antiviral activity. Recent studies of ISG15 have re-established that ISG15 is also a secreted molecule with cytokine-like properties. However, the potential ability of ISG15 to influence the Th1 and CD8 T cell immune responses and act a vaccine adjuvant, has not been well defined. To this end, we developed a highly optimized DNA-vector encoding the ISG15 protein and evaluated its immunogenicity to increase the cellular immune responses in combination with a DNA consensus-based fusion HPV16 E6/E7 construct. We demonstrate that ISG15 can enhance Ag-specific Th1 memory responses to HPV16 E6/E7 antigen by IFN-γ ELISpot analysis. Moreover, ISG15 elicited strong HPV16 Ag-specific polyfunctional CD8+ T cells that secrete both anti-viral IFN-γ and/or TNF-α cytokines. Vaccination conferred remarkable 100% protection against challenge with HPV E6 and E7-expressing tumors. Overall, these findings lay the groundwork of ISG15 as a new immunoadjuvant candidate in the context of cancer immunotherapy.

Citation Format: Daniel Villarreal, Megan C. Wise, Jian Yang, David B. Weiner. Immunoadjuvant ISG15 enhances human papillomavirus 16 antigen-specific cell-mediated antitumor immunity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-257. doi:10.1158/1538-7445.AM2014-LB-257
Abstract LB-266: Generation of antagonistic anti-TIM-3 and anti-LAG-3 monoclonal antibodies for potential novel immunotherapy combinations
Authors: Jun H. Toni , McNeeley Patricia A. , Lassen Andrew , Hynes Brandon , Altobell Larry , Chhoa Mark , Olvera Jesus , MacLaren Josh , Do Minjee , Brown Michael , Correia Jean da Silva , King David
Published: May 2015

Among the most promising approaches in the treatment of cancer is the activation of antitumor immunity by blockade of immune checkpoints. These inhibitory immune checkpoints are crucial for maintaining self-tolerance in the normal immune system but can be co-opted in cancer to allow tumor escape from immune surveillance. Therapeutic validation has been provided using antibodies that inhibit the CTLA-4 and PD-1 signaling pathways, which have shown significant clinical activity. Interestingly, blockade of other T-cell inhibitory signaling molecules TIM-3 and LAG-3 has also been shown to be effective in mouse models of cancer. Potential therapeutic molecules that inhibit the negative signaling of TIM-3 or LAG-3 were identified by screening the AnaptysBio Evolvable Library (ABEL) of fully human germline antibodies. The initial ABEL screens used the soluble extra cellular domains (ECD) of either TIM-3 or LAG-3, followed by screening on cell-surface expressed antigens. The resulting panels of human antibodies were matured to high affinity and potency using SHM-XEL™ which uses mammalian cell display of human IgG followed by in vitro somatic hypermutation (SHM). We have explored the activity of these antibodies both as single agents as well as simultaneous blockade of multiple pathways in in vitro cell-based assays. Inhibition of each pathway in isolation demonstrated immune stimulatory activity as evidenced by increased secretion of IL-2 in a mixed lymphocyte reaction or an activated T-cell assay. Combination of an anti LAG-3 or an anti TIM-3 antibody with an anti-PD-1 inhibitory antibody could increase IL-2 secretion over that seen with blockade of a single checkpoint alone. The magnitude of this effect was donor cell dependent. These data are suggestive that combination immunotherapy towards these targets is worthy of clinical evaluation and may lead to increased efficacy.

Citation Format: H. Toni Jun, Patricia A. McNeeley, Andrew Lassen, Brandon Hynes, Larry Altobell, Mark Chhoa, Jesus Olvera, Josh MacLaren, Minjee Do, Michael Brown, Jean da Silva Correia, David King. Generation of antagonistic anti-TIM-3 and anti-LAG-3 monoclonal antibodies for potential novel immunotherapy combinations. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-266. doi:10.1158/1538-7445.AM2014-LB-266
Abstract LB-27: Develop mutant isocitrate dehydrogenase 1 (IDH1)-expressing gliomas using RCAS/tv-a technology
Authors: Kim Youngmi , Lindberg Nanna , Bolouri Hamid , Delrow Jeffrey , Ozawa Tatsuya , Holland Eric
Published: May 2015

Malignant brain tumors are the second leading cause of cancer deaths in people under the age of 35, and median survival for glioblastomas, the most aggressive brain tumor, is only 12-14 months. A recent genomewide mutational analysis of glioblastomas discovered that somatic mutations of the isocitrate dehydrogenase 1 gene (IDH1) most frequently occur in young glioma patients. A point mutation at codon 132 of IDH1 synthesizes 2-Hydroxyglutarate (2-HG), which results in the disruption of many enzymatic reactions and alters epigenetics. Although many independent research groups have explored brain tumors expressing mutant IDH1 (muIDH1) and worked toward developing inhibitors for this particular target, the lack of suitable brain tumor models for muIDH1 hinders research progress. Thus, we utilize RCAS/tv-a technology to create muIDH1-expressing murine brain tumors. The preliminary data demonstrates that our murine gliomas express muIDH1, and their molecular profiling is similar to human muIDH1-expressing glioma. We believe that our muIDH1-expressing murine glioma model may benefit many aspects of research: from studying gliomagenesis of muIDH1-expressing gliomas to developing specific targets and performing clinical trials for this glioma subtype.

Citation Format: Youngmi Kim, Nanna Lindberg, Hamid Bolouri, Jeffrey Delrow, Tatsuya Ozawa, Eric Holland. Develop mutant isocitrate dehydrogenase 1 (IDH1)-expressing gliomas using RCAS/tv-a technology. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-27. doi:10.1158/1538-7445.AM2014-LB-27
Abstract LB-279: Nonsteroidal anti-inflammatory drug (NSAID) use and risk of lethal renal cell carcinoma
Authors: Preston Mark A. , Cheng Jed-sian , Barrisford Glen , Sanchez Alex , Feldman Adam S. , Rodriguez Dayron , Choueiri Toni K. , Stampfer Meir , Willett Walter C. , Cho Eunyoung
Published: May 2015

Background: Studies suggest that non-steroidal anti-inflammatory drug (NSAID) use may increase risk of renal cell cancer (RCC), but the relationship to the lethal form of RCC remains unknown.

Methods: We examined the relationship between NSAID use and RCC risk in two large prospective cohorts: the Nurses’ Health Study and the Health Professionals Follow-up Study. Use of aspirin and other NSAIDs was ascertained in 1990 in the Nurses’ Health Study and in 1986 in the Health Professionals Follow-up Study, and every 2 years thereafter. We evaluated baseline use and duration of NSAID use. We defined the lethal form of RCC as RCC that resulted in death due to the disease.

Results: During follow-up of 18 years among 77,524 women and 20 years among 49,403 men, we documented 364 cases of RCC, of which 102 were fatal. Regular use of non-aspirin NSAIDs was associated with an increased overall RCC risk; there was a dose-response relationship between duration of non-aspirin NSAID use and RCC risk; compared with non-regular use, the pooled multivariable relative risks (RRs) were 0.78 (95% CI, 0.58-1.06) for use of less than 4 years, 1.29 (95% CI, 0.95-1.74)) for 4 to less than 10 years, and 2.21 (95% CI 1.39-3.49) for use for 10 or more years (P for trend, 0.0006). Furthermore, non-aspirin NSAID users of 4-10 years (pooled multivariable RR 3.13, 95% CI 1.70-5.77) and more than 10 years (pooled multivariable RR 7.23, 95% CI 2.51-20.83) had a significantly increased risk of lethal RCC. Aspirin use was not associated with increased risk of overall (pooled multivariable RR 1.07, 95% CI 0.84-1.34) or lethal RCC (pooled multivariable RR 1.59, 95% CI 0.85-2.96).

Conclusion: Our prospective data suggest that non-aspirin NSAID use is associated with an increased incidence of RCC, especially the lethal form of RCC.

Citation Format: Mark A. Preston, Jed-sian Cheng, Glen Barrisford, Alex Sanchez, Adam S. Feldman, Dayron Rodriguez, Toni K. Choueiri, Meir Stampfer, Walter C. Willett, Eunyoung Cho. Nonsteroidal anti-inflammatory drug (NSAID) use and risk of lethal renal cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-279. doi:10.1158/1538-7445.AM2014-LB-279
Abstract LB-295: The roles of genetic polymorphisms for susceptibility of colorectal cancer in Chinese Lynch syndrome families
Authors: Yeh Chih-Ching , Tang Reiping , Chien Huei-Tzu , Lai Chih-Hsiung , Chiu Li-Ling , Lo Tsai-Ping , Hung Kuan-Yi , Wang Chun-Yi , You Jeng-Fu , Hsiung Chao A. , Hsieh Ling-Ling
Published: May 2015

Background: Lynch syndrome is associated with germ-line mutations in DNA mismatch repair (MMR) genes. Polymorphisms in candidate genes that have been implicated in sporadic colorectal cancer (CRC) risk may also play roles in hereditary CRC risk. In this retrospective analysis, we examined multiple polymorphisms (including MSH2 IVS10+12A>G, MLH1 A-93G, NAT1, GSTM1, GSTP1 Iel105Val, GSTA1 C-69T, TP53 Arg72Pro, CYP17A1 T-34C, CYP1A1*2C, CYP1A1*1F, TGFBR1 IVS7+24G>A, and TGFBR2 G-875A) to assess the genetic effect on the CRC risk in MLH1 and MSH2 mutation carriers.

Material and Methods: DNA samples from 284 mutation-positive Lynch syndrome participants were genotyped by Sequenom iPLEX MassArray. Univariate and multivariate analysis was used to analyze the association between the genetic polymorphisms and CRC risk.

Results: We found significant associations between the presence of variant alleles in TP53 Arg72Pro (G>C) and TGFBR2 G-875A genes and the risk of developing CRC among MLH1 and MSH2 mutation carriers. The TP53 Arg72Pro GC+CC genotypes were associated with decreased risk of CRC (hazard ratio (HR) = 0.63, 95% confidence interval (CI) = 0.42-0.94). However, the TGFBR2 G-875A GA+AA genotypes were associated with increased risk of CRC (HR = 1.60, 95% CI = 1.06-2.42). None of the other gene polymorphisms examined were associated with CRC risk.

Conclusion: To our best knowledge, our study is the first and largest study investigating multiple genetic modifiers that may influence CRC risk in Chinese Lynch syndrome families. Our results suggested that TP53 and TGFBR2 polymorphisms may associate with CRC risk among MLH1 and MSH2 mutation carriers. Such knowledge may be helpful in identifying high-risk individuals who require more intensive surveillance.

Citation Format: Chih-Ching Yeh, Reiping Tang, Huei-Tzu Chien, Chih-Hsiung Lai, Li-Ling Chiu, Tsai-Ping Lo, Kuan-Yi Hung, Chun-Yi Wang, Jeng-Fu You, Chao A. Hsiung, Ling-Ling Hsieh. The roles of genetic polymorphisms for susceptibility of colorectal cancer in Chinese Lynch syndrome families. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-295. doi:10.1158/1538-7445.AM2014-LB-295
Abstract LB-297: Mortality trends from lung and bronchus cancer in Boone County, W.V., USA before and after mountaintop removal mining practices
Authors: Crosby Lynn M. , DeVera Christina , Charles Kaylene , Orem William
Published: May 2015

Publically-available databases (CDC/NCI) report causes of mortality at the national, state and recently, county level. However, county or sub-county-wide health in West Virginia is difficult to assess due to the rural, sparse and isolated nature of many counties. In Boone County, WV, villages are arranged in a narrow, winding valley or ‘hollow’ lying between mountain peaks and situated along a creek or river. This region, rich with subterranean coal seams, has been mined for over 100 years; however, mountaintop removal mining (MTR), which began in the 1980s, now allows for the removal of previously-inaccessible seams by surface mining techniques in the top third of a mountain. Mountaintop removal mining has increased dramatically and current estimates suggest greater than 30 percent of West Virginia’s coal is produced using this technique. For people residing near MTR sites, dust particulates or other mobilized constituents (minerals, metals, coal, or excipients) may present a health hazard by entering the food chain via vegetables or fruit grown in a home garden, through drinking water, or by breathing or ingestion. To evaluate whether the rate of lung and bronchus cancer deaths have changed over the past fifty years, mortality records were examined from 1962 and 1972-3 (before mountaintop mining removal was widely used) and compared with those from 2006-12. The Chi-squared statistic was used to compare the frequency distributions for the rate of lung and bronchus cancer deaths in eight age categories between 1962, 1972-3, and 2006-12. We found the three time periods were significantly different from one another (α=0.005), and that the number of lung and bronchus cancer deaths had increased in those aged 45 years or older. Smoking rates and socioeconomic status within the county have remained relatively constant during the past decade. Taken together societal and environmental changes and medical advances have influenced causes of mortality in this coal-rich Appalachian county.

Citation Format: Lynn M. Crosby, Christina DeVera, Kaylene Charles, William Orem. Mortality trends from lung and bronchus cancer in Boone County, W.V., USA before and after mountaintop removal mining practices. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-297. doi:10.1158/1538-7445.AM2014-LB-297
Abstract LB-3: Apolipoprotein (E) is a determinant of colon carcinogenesis potentially by regulating inflammation and β-catenin independently of its role in lipid metabolism
Authors: Elbahrawy Ali I. , Tarhuni Abdelmetalab , Naura Amarjit S. , Errami Youssef , Alwan Mohamed , Hammad Samar , Trillo-Tinoco Jimena , Hemeida Ramadan , Brim Hassan , Ashktorab Hassan , Valle Luis Del , Boulares Hamid A.
Published: May 2015

Colorectal cancer is a leading cause of cancer-related mortality. Apolipoprotein E (ApoE) is a major player in cholesterol metabolism and has been suggested, through association studies, to play a role in colon homoeostasis and cancer. Genetic studies suggested that polymorphisms in the ApoE alleles constitute a risk factor for the development of colon cancer. Collectively, these studies explored the role of ApoE in colon cancer by narrowly focusing on its established function in lipid metabolism. In the current study, we utilized a genetic mouse model (ApcMin mouse) of colon cancer to test the hypothesis that ApoE is a determinant in the disease progression. We show that ApoE gene heterozygosity, which reduces the protein (∼50%) and minimally affects the lipid profile, significantly increased tumor burden in ApcMin mice both in the small intestine and the colon. Surprisingly, ApoE gene knockout, which completely eliminates the protein and drastically elevates the lipid profile, did not aggravate the tumor burden in ApcMin mice compared to that caused by gene heterozygosity, suggesting a novel and cholesterol-metabolism-independent function for ApoE in colon homeostasis. In vitro studies with primary colon epithelial cells, isolated using a novel technique developed by our laboratory, show that ApoE-deficiency achieved by ApoE heterozygosity, knockout, or knockdown increased the level of active β-catenin in the absence of any stimulation. It appears that such increase in β-catenin may be at an mRNA level. ApoE deficiency was also associated with an increase in inflammatory factors including VCAM-1, MCP-1, and COX-2 in TNF-treated colon epithelial cells. Altogether, our preliminary results suggest a major role of ApoE in colon homeostasis and that deficiency in ApoE levels may constitute a risk factor for colon cancer progression.

Citation Format: Ali I. Elbahrawy, Abdelmetalab Tarhuni, Amarjit S. Naura, Youssef Errami, Mohamed Alwan, Samar Hammad, Jimena Trillo-Tinoco, Ramadan Hemeida, Hassan Brim, Hassan Ashktorab, Luis Del Valle, Hamid A. Boulares. Apolipoprotein (E) is a determinant of colon carcinogenesis potentially by regulating inflammation and β-catenin independently of its role in lipid metabolism. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-3. doi:10.1158/1538-7445.AM2014-LB-3
Abstract LB-306: The Ras exchange factor RasGRP1 opposes proliferative EGFR-SOS1 Ras signals and restricts intestinal epithelial cell growth
Authors: Depeille Philippe , Henricks Linda M. , Ven Robert van de , Lemmens Ed , Matli Mary , Haigis Kevin M. , Donner David , Warren Robert , Roose Jeroen P.
Published: May 2015

The character of EGFR signals can influence cell fate. Anti-EGFR treatment has been successful as cancer therapy but not in colorectal cancer (CRC) where activating somatic KRAS mutations (KRASMUT) are prevalent. While relevant to CRC, intestinal EGFR signaling is poorly understood, particularly in the context of KRASMUT. Here we show that two distinct Ras nucleotide exchange factors, RasGRP1 and SOS1, lie downstream of the EGFR but act in functional opposition to one another in the context of KRASMUT. RasGRP1 creates a negative feedback loop that limits EGFR-SOS1-Ras signals and restricts CRC growth. Genetic Rasgrp1 depletion from KRasMUT mice exacerbates intestinal epithelial cell growth and dysplasia, leading to a highly serrated colonic epithelium. Furthermore, low RasGRP1 expression in CRC patient specimens correlates with poor clinical outcome. The unexpected inhibitory role of EGFR-RasGRP1 signals in KRASMUT gastrointestinal malignancies reveals an intricacy of EGFR signaling that should be considered for future molecular therapeutics.

Citation Format: Philippe Depeille, Linda M. Henricks, Robert van de Ven, Ed Lemmens, Mary Matli, Kevin M. Haigis, David Donner, Robert Warren, Jeroen P. Roose. The Ras exchange factor RasGRP1 opposes proliferative EGFR-SOS1 Ras signals and restricts intestinal epithelial cell growth. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-306. doi:10.1158/1538-7445.AM2014-LB-306
Abstract LB-307: Giα proteins exhibit functional differences in activation of ERK1/2, Akt and mTORC1 by growth factors in normal and breast cancer cells
Authors: Chu Wen-Ming
Published: May 2015

Background

In a classic model, Giα proteins, Gi1α, Gi2α and G3α, are important for transducing signals from Gi protein-coupled receptors (GPCRs) to their downstream cascades in response to hormones and neurotransmitters. Our previous study has suggested that Giα proteins are also important for activation of the PI3K/Akt/mTORC1 pathway by epidermal growth factor (EGF) and its family members. However, a genetic role of Giα proteins in activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) by EGF is largely unknown. Further, it is not clear whether Giα proteins are also engaged in activation of both the Akt/mTORC1 and ERK1/2 pathways by other growth factor family members. Additionally, a role of Giα proteins in breast cancer remains to be elucidated.

Results

We found that Giα deficient MEFs showed defective ERK1/2 activation by EGFs, IGF-1 and insulin, and Akt and mTORC1 activation by EGFs and FGFs. Giα1/2/3 knockdown breast cancer cells exhibited a similar defect in this activation and a defect in in vitro growth and invasion. Giα proteins associated with RTKs, Gab1, FRS2 and Shp2 in breast cancer cells and their ablation impaired Gab1's interactions with Shp2 in response to EGF and IGF-1, or with FRS2 and Grb2 in response to bFGF.

Conclusions

Giα proteins differentially regulate activation of Akt, mTORC1 and ERK1/2 by different families of growth factors. Giα proteins are important for breast cancer cell growth and invasion.

Citation Format: Wen-Ming Chu. Giα proteins exhibit functional differences in activation of ERK1/2, Akt and mTORC1 by growth factors in normal and breast cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-307. doi:10.1158/1538-7445.AM2014-LB-307