bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2507: Genetic alterations affecting treatment response in locally advanced breast cancers
Authors: Venizelos Andreas , Knappskog Stian , Loees Inger Marie , Eikesdal Hans Petter , Lønning Per Eystein
Published: August 2019

Resistance to chemotherapy remains a main cause of death among cancer patients. The primary aim of the present study was to identify genetic alterations predicting resistance to chemotherapy by whole exome sequencing (WES) of tumors subject to neoadjuvant sequential treatment with epirubicin and docetaxel. A long term goal is to identify biomarkers that may be applicable in testing for drug sensitivity prior to commencement of therapy for individual patients, leading to early administration of optimal treatment and sparing patients from side-effects of inefficient treatment. From a total of 100 patients treated with sequential monotherapy in the neoadjuvant setting, we performed WES on 146 tumor samples and matching blood samples from 51 patients. Biopsies for research were taken before treatment start, at the time of treatment switch and at the time of surgery. In the present work, we have analysed WES data to assess the mutational- and the copy number landscape and compared these results between patients having a good or poor response to the two administered drugs. SNV analysis revealed imbalance in several well established breast cancer related genes, between the different response groups. Copy number assessments revealed a general increase in copy number gains in chromosome 16 and increase of copy number losses in chromosomes 1 and X after treatment with epirubicin, indicating that subclones harbouring different types of CNVs are selected for during treatment. Correspondingly, after treatment with docetaxel we found a general increase of copy number gains in chromosome 8 and an increase of copy number losses in chromosomes 1 and 8. Finally, we assessed overall mutational signatures and observed shifts in these profiles during the two treatments.

Citation Format: Andreas Venizelos, Stian Knappskog, Inger Marie Loees, Hans Petter Eikesdal, Per Eystein Lønning. Genetic alterations affecting treatment response in locally advanced breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2507.
Abstract 2508: Genomic alterations of BRCA1/2 genes in Chinese solid tumor patients
Authors: Wang Junjian , Liu Lingxiang , Ni Bin , Chen Xiaoqian , Li Ling , Shi Junping , Chen Jierong , Yao Ming
Published: August 2019

Background: BRCA1 and BRCA2 are tumor suppressor genes that play an important role in DNA repair pathways. Germline mutations in BRCA1 and BRCA2 contribute to a significant number of familial and hereditary breast and/or ovarian cancers. Additionally, BRCA 1/2 alterations induce sensitivity to poly ADP ribose polymerase inhibitors (PARPi). Therefore, the detection of BRCA 1/2 mutations in solid tumor patients is essential to predict the sensitivity to PARPi therapy.

Methods: FFPE tumor and matched blood samples of 5269 Chinese patients with solid tumor were collected for next generation sequencing (NGS) based assay. Genomic alterations including single nucleotide variations (SNV), short and long insertions/deletions (Indel), copy number variations (CNV) and gene rearrangements and fusions in selected genes were assessed.

Results: Three hundred patients with BRCA1/2 mutations were identified in 5269 Chinese patients with solid tumor. The patients included 177 males and 123 females with a median age of 58. Highest yields of BRCA1/2 mutations were found in patients with ovarian (24.5%) and breast (12.3%) cancers. BRCA1/2 mutations were also identified in gastric cancer (8.9%), cholangiocarcinoma (8.8%), colorectal cancer (7.1%), esophageal cancer (6.1%), gallbladder cancer (5.1%), lung cancer (4.7%), soft tissue tumor (4.1%) and pancreatic cancer (4.0%). SNVs and short Indels (84.9%) were the most common variant types of BRCA1/2, while the percentages of gene rearrangements and fusions, CNV and long Indels were 12.0%, 1.6% and 1.5%, respectively. Among patients with BRCA1/2 mutations, 224 (74.7%) patients harbored somatic mutations, 73 (24.3%) patients harbored germline mutations, 3 (1.0%) patients harbored both somatic and germline mutations. Interestingly, all of the variant types of germline mutations were SNVs and short Indels. The mutation sites were distributed in the full length of BRCA1/2 genes. No hot spot mutation was observed.

Conclusions: Our data revealed that BRCA1/2 mutations occurred in 5.7% of Chinese patients with solid tumor. NGS targeted sequencing provides comprehensive and accurate information of BRCA1/2 mutations. Beyond ovarian and breast cancers, BRCA1/2 mutations could be detected in other solid tumors, which suggests potential clinical benefits from PARPi therapy.

Citation Format: Junjian Wang, Lingxiang Liu, Bin Ni, Xiaoqian Chen, Ling Li, Junping Shi, Jierong Chen, Ming Yao. Genomic alterations of BRCA1/2 genes in Chinese solid tumor patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2508.
Abstract 2524: Hallmarks of kinase fusions in Chinese tumors
Authors: Shi Lin , Ce Limuge , Wang Yanyan , Zhou Zisong , Ma Jing , Dong Hua , Ye Yizhou , Sun Shuyang
Published: August 2019

Kinase fusions are essential drivers to tumor genesis and generally response well to kinase inhibitors. Kinase fusion protein often represent ideal targets and many fusion genes have been well established as therapeutic targets as well as biomarkers, such as BCR-ABL fusion in CML and ALK fusion in lung cancer. In a CAP certified lab 3DMed we describe here a pan-cancer analysis of 8599 patient samples from assayed with comprehensive genomic profiling. Tissue samples were sequencing with a lab validated Masterview gene panel with intronic baiting for 30 fusion genes. Plasma samples were sequencing with a lab validated CGP150 gene panel with intronic baiting for 16 fusion genes. The kinase fusions genes we analyzed are included in both gene panels. Fusions were detected by a sensitive, breakpoint based method and the results were confirmed by manual inspection of the soft-clipped reads. Tumor mutational burden (TMB) was determined by coding region SNV and indel variant counts per Mb for tumor tissue sample only. We collect evidence for all possible gene fusion alterations in all the qualified samples and then focused on the analysis of kinase fusions in lung tissue samples. We surveyed gene fusions across 20 solid tumor types. 196/8599 (2.3%) samples harbored kinase fusion. 31.7% samples are from lung cancer patients and 74% of the 196 kinase fusions are found in lung cancer samples. The average of TMB score in kinase fusion positive samples was 5.17 vs. 11.35 (Wilcox test, P < 0.001) for lung cancer cases. 13% of the kinase fusions positive lung cancer samples co-occur with a known driver mutation such as EGFR or ALK mutation. TMB score in subgroup with kinase fusion (with or without another oncogene driver mutation) is significantly lower than that of subgroup without fusion (Wilcox test, P < 0.01). TMB scores in the kinase fusion positive patients is significantly lower than the fusion negative patients, which suggests that the kinase fusion positive subgroup may not response well to the immune checkpoint inhibitor. There are unmet clinical needs for more fusion kinase inhibitors with the increasing detection sensitivity for kinase fusions by NGS. Our finding have immediate clinical implications for cancer diagnosis and expand the therapeutic options for cancer patients’ care, as approved or exploratory drugs exist for many of these kinases.

Citation Format: Lin Shi, Limuge Ce, Yanyan Wang, Zisong Zhou, Jing Ma, Hua Dong, Yizhou Ye, Shuyang Sun. Hallmarks of kinase fusions in Chinese tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2524.
Abstract 2540: Mitotic Golgi vesiculation enables human papillomavirus to evade cGAS/STING
Authors: Forte Brittany L. , Bratton Shauna M. , Campos Samuel K.
Published: August 2019

Oncogenic human papillomaviruses (HPVs) infect and replicate in differentiating mucosal epithelium, causing 5% of cancers worldwide and essentially all cervical cancers. During infection, HPV must traffic viral genome (vDNA) to the nuclei of basal keratinocytes. Minor capsid protein L2 facilitates intracellular transport of vDNA to the Golgi; upon mitosis, the L2-vDNA complex penetrates limiting membranes and localizes to mitotic chromosomes, ensuring infection of both daughter cells.

Cytosolic DNA sensor cGAS recognizes cytosolic dsDNA and produces second messenger cGAMP; cGAMP causes activation and relocalization of ER-resident STING to the Golgi, where it recruits TBK1 to phosphorylate and activate IRF3, initiating a type-I IFN response. The cGAS/STING pathway is assumed, though never demonstrated, to be inactive during mitosis to avoid detecting self-DNA. Since the Golgi is a platform for STING/TBK1/IRF3 recruitment and activation, we hypothesize natural Golgi dispersal deactivates cGAS/STING during mitosis. Further, we hypothesize HPV has evolved to traffic to and translocate from the mitotic Golgi as an immunoevasive tactic to avoid detection by cGAS/STING during mitosis.

HaCaTs, a human keratinocyte line, were transfected with DNA or infected with HPV pseudovirions and analyzed for cGAS/STING activation. DNA transfection resulted in IRF3 phosphorylation and nuclear translocation, and STING translocation to the Golgi, indicating cGAS/STING activity. Strikingly, chemical disruption of the Golgi ribbon potently blocked IRF3 activation in response to foreign DNA, suggesting Golgi morphology might modulate cGAS/STING activity during mitosis. In accordance, DNA-dependent IRF3 phosphorylation was transiently reduced in synchronized mitotic cells, but chemical impairment of mitotic Golgi vesiculation enabled cGAS/STING activation, even without foreign DNA transfection. Further, HPV infection resulted in minimal IRF3 phosphorylation, indicating HPV can efficiently evade detection during initial infection.

To determine if HPV’s unique trafficking enables evasion, we used cationic liposomes to permit premature virion translocation across limiting membranes. Such treatment renders a non-infectious, translocation-defective mutant HPV infectious, yet susceptible to cGAS/STING sensing. Overall, the cGAS/STING pathway may be inactivated by mitotic Golgi dispersal, allowing HPV to evade detection during mitosis.

Citation Format: Brittany L. Forte, Shauna M. Bratton, Samuel K. Campos. Mitotic Golgi vesiculation enables human papillomavirus to evade cGAS/STING [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2540.
Abstract 2556: Enhanced expression of human cyclin G1 (CCNG1) gene in metastatic cancer, a novel biomarker in development for CCNG1 inhibitor therapy
Authors: Gordon Erlinda M. , Szeto Christopher , Ravicz Joshua R. , Reddy Sandeep , Morse Michael , Chawla Sant , Hall Frederick
Published: August 2019

Background: Metastatic cancer is associated with, hitherto, an invariably fatal outcome. DeltaRex-G, a CCNG1 inhibitor, has induced long term (9-12 year-) survivorship in patients with metastatic melanoma, sarcoma, lymphoma and cancer of pancreas and breast.

Purpose: To evaluate CCNG1 expression in tumors as a novel biomarker for identification of patients who are likely to benefit from CCNG1 inhibitor therapy.

Methods: RNA sequence analysis was used to compare CCNG1 expression in tumor (TCGA, N=9161) versus normal tissues (TGCA, N=678 and GTEx, N=7187) from 20 organ sites, and in primary vs metastatic melanoma (N=106 & 367 respectively). Using IHC staining, the significance of differences between the number of CCNG1+ and Ki-67+ cells in normal tissues vs tumors were evaluated using paired Student’s t test. Pearson’s coefficient of correlation was used to evaluate the relationship between the number of Ki-67+ vs CCNG1+ cells.

Results: CCNG1 gene expression, by RNA sequence analysis, was significantly enhanced in melanoma, sarcoma, leukemia, and cancers of the lung, thyroid, brain, liver, prostate, testicle, head and neck, bladder, kidney, adrenal, cervix, and pancreas, compared to normal tissues (p = 0.006- 1.8E-58), and even greater, in metastatic vs primary melanoma. In a subset of melanoma tumors, there was overall positive correlation with progression/metastasis in both Ki67 and CCNG1 expression levels. Consistent with these findings, IHC showed significant differences when comparing CCNG1 nuclear staining percentages between analogous healthy and cancerous tissues (p = 0.002, df = 11). The nuclear staining percentages of CCNG1 and Ki-67 share a statistically significant, positive correlation (r = .936977, p < 0.00001). Further, in some patients, the level of CCNG1 expression by IHC fluctuated over time.

Conclusion: Taken together, these data indicate that (1) CCNG1 expression, is frequently enhanced in cancerous tumors compared to their normal analogous counterparts, and (2) the level of CCNG1 expression may change over time, necessitating real time analysis in order to determine the optimal timing for CCNG1 inhibitor therapy. A Phase 2 basket study of DeltaRex-G cell cycle checkpoint inhibitor therapy is planned to correlate treatment outcome parameters with CCNG1 expression in patients’ tumors and circulating tumor cells.

Citation Format: Erlinda M. Gordon, Christopher Szeto, Joshua R. Ravicz, Sandeep Reddy, Michael Morse, Sant Chawla, Frederick Hall. Enhanced expression of human cyclin G1 (CCNG1) gene in metastatic cancer, a novel biomarker in development for CCNG1 inhibitor therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2556.
Abstract 2599: Pleiotropic effects of PPARD accelerate colorectal tumorigenesis progression and invasion
Authors: Liu Yi , Deguchi Yasunori , Tian Rui , Wei Daoyan , Wu Ling , Chen Weidong , Xu Weiguo , Xu Min , Liu Fuyao , Gao Shen , Jaoude Jonathan C. , Chrieki Sarah P. , Moussalli Micheline J. , Gagea Mihai , Morris Jeffrey S. , Broaddus Russell , Zuo Xiangsheng , Shureiqi Imad
Published: August 2019

APC mutations activate aberrant β-catenin signaling to drive colorectal cancer (CRC) initiation. CRC progression however requires additional molecular mechanisms. PPAR-delta (PPARD) is a downstream target of β-catenin and upregulated in CRC. PPARD germline genetic deletion has however been reported to promote intestinal tumorigenesis in Apcmin mice, which has questioned PPARD effects on β-catenin aberrant activation and CRC. Addressing this knowledge gap is important because PPARD is a druggable protein. Mice with targeted PPARD overexpression/deletion into intestinal epithelial cells (IECs) were bred with mice with intestinally targeted ApcΔ580 mutation via CDX2-cre (ApcΔ580) or CDX2-cre-ERT2 (ApcΔ580-TMX). APCΔ580 mice treated with PPARD agonist (GW501516) or antagonist (GSK3787), and human CRC organoid cells were also tested. PPARD expression was examined in human CRC invasive fronts and their paired colorectal adenomas and cancer centers. PPARD’s mechanisms to promote CRC were screened by Functional Proteomics Reverse Phase Protein Assay (RPPA) and subsequently validated in in-vitro and in-vivo studies. PPARD overexpression/deletion in IECs in mice augmented/suppressed β-catenin activation via upregulation/downregulation of BMP7/TAK1 signaling and strongly promoted/suppressed CRC .PPARD downregulation by siRNA in human CRC organoid cells inhibited BMP7/β-catenin signaling and suppressed organoid self-renewals. GW501516 enhanced while GSK3787 suppressed CRC tumorigenesis in ApcΔ580 mice. PPARD expression was significantly higher in human CRC invasive fronts versus their paired invasive tumor centers and adenomas. RPPA and validation studies identified PPARD upregulation of multiple other pro-invasive pathways: PDGFRβ, connexin 43, AKT1, EIF4G1 and CDK1, Our data demonstrate that PPARD strongly potentiates multiple pro-tumorigenic pathways to promote CRC progression and invasiveness.

Citation Format: Yi Liu, Yasunori Deguchi, Rui Tian, Daoyan Wei, Ling Wu, Weidong Chen, Weiguo Xu, Min Xu, Fuyao Liu, Shen Gao, Jonathan C. Jaoude, Sarah P. Chrieki, Micheline J. Moussalli, Mihai Gagea, Jeffrey S. Morris, Russell Broaddus, Xiangsheng Zuo, Imad Shureiqi. Pleiotropic effects of PPARD accelerate colorectal tumorigenesis progression and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2599.
Abstract 2606: Genetic contribution of MYC to the development of primary prostate cancer
Authors: Whitlock Nichelle C. , Trostel Shana , Atway Rayann , Walton Elizabeth , Capaldo Brian J. , Ye Huihui , Sowalsky Adam G.
Published: August 2019

Despite the predictive value of Gleason score (Gs), the molecular characteristics and associated biology that underpin specific Gleason patterns (Gp) remain understudied. Based on previous data showing increased MYC activity in higher-grade Gp4 versus lower-grade Gp3 tumor foci and addressing the paradox that prostate cancer is not hyper-proliferative, we sought to examine the genetic contribution of MYC to locally-advanced prostate cancer development. We screened a series of Gs7 cancers in which the Gp3 and Gp4 components were adjacent and represented contributing elements of the index lesion. Tumor foci were collected by laser capture microdissection based on MYC staining and purified for RNA; transcriptome profiling was performed. To further guide our bioinformatics analyses, we generated a LNCaP prostate cancer cell line harboring MYC knockdown. RNA-seq and ChIP-seq was performed to identify differentially bound regions of the cistrome that correlate with altered gene expression and elucidate potential mechanism(s) of action for MYC in primary prostate cancer. In contrast to other reports, MYC knockdown had the effect of increasing global transcription. Moreover, the publicly available Cancer Genome Atlas (TCGA) prostate cancer dataset was curated according to MYC status based on extreme case design using reverse phase protein assay data. Preliminary results show: (1) increased MYC protein levels, but not proliferation, in Gp4 tumor foci as compared to adjacent Gp3, (2) distinct histology and biology based on MYC tumor status, and (3) found recurrent enrichment for gene sets cross-referencing differentially expressed genes between TCGA, tissue, and our engineered cell line. Of note, we observed recurrent enrichment for the Acosta Proliferation Independent MYC Targets Up gene set, which correlated with MYC activity. When this gene set was cross-referenced between all three datasets, the gene NOLC1 was identified. Nucleolar and coiled-body phosphoprotein 1 (NOLC1) plays an important role in rRNA synthesis and ribosome biosynthesis; its role in tumorigenesis appears context dependent. NOLC1 was found to be positively correlated with MYC expression and may thus contribute to MYC-driven prostate cancer. Although further cases are needed to determine the frequency at which NOLC1 drives MYC-driven prostate cancer, our results suggest a novel role for MYC in mediating development of locally-advanced prostate cancer.

Citation Format: Nichelle C. Whitlock, Shana Trostel, Rayann Atway, Elizabeth Walton, Brian J. Capaldo, Huihui Ye, Adam G. Sowalsky. Genetic contribution of MYC to the development of primary prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2606.
Abstract 2625: Identification of CTX-30916 as a novel antagonist of progesterone receptor signaling pathways
Authors: Lala Deepak , Haque Tasir
Published: August 2019

Breast cancer is the most commonly diagnosed cancer in women and the second leading cause of cancer related death in women. Progesterone is a major mitogen in the adult human mammary epithelium that, in addition to estrogen, is a key driver of breast cancer cell proliferation. Activated PR signaling through MAPK-driven phosphorylation of the progesterone receptor (PR) is also an important driver of breast cancer stem cells. PR expression is associated with the presence of estrogen receptor-alpha (ESR1) mutations that are constitutively active and linked to resistance in the clinic in response to aromatase inhibitors, antiestrogens and CDK4/6 inhibitors. Thus, PR may play a role in tumor relapse and resistance in the clinic and blocking both estrogen and progesterone receptors would likely be an effective approach in 2L treatment for patients with advanced breast cancer. There is great interest in evaluating antiprogestins in the clinic in combination with antiestrogens or CDK4/6 inhibitors. Apristor®, an extended release formulation of onapristone, a full antagonist of PR, that has efficacy in multiple in vivo and in vitro models in combination with antiestrogestins and CDK4/6 inhibitors, is currently being evaluated in several human clinical trials.

In this study we have examined the in vitro properties of CTX-30916, a novel mono-N-desmethyl analog of onapristone. CTX-30916 binds potently to PR and acts as an antagonist in cell-based transfection assays. CTX-30916 displays selectivity against other steroid receptors in binding assays and is also a potent inhibitor of T47D breast cancer cell proliferation. Interestingly, CTX-30916 leads to a unique co-regulator binding pattern in the Microarray Assay for Real-time Co-regulator-Nuclear receptor interaction (MARCoNI) assay compared with onapristone and mifepristone indicating that the co-regulator peptide-PR interaction landscape is different between the various antiprogestins. These data suggest that CTX-30916 binding to PR leads to a distinct receptor conformation and antagonizes PR signaling pathways in cancer through a unique mechanism of action compared to other antiprogestins.

Citation Format: Deepak Lala, Tasir Haque. Identification of CTX-30916 as a novel antagonist of progesterone receptor signaling pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2625.
Abstract 2643: TNFAIP2 interacts with EGFR to modulate EGF-induced EGFR auto-phosphorylation and internalization and sequential ERK1/2 activation in nasopharyngeal carcinoma cells
Authors: Liu Hao-Ping , Wu Chih-Ching
Published: August 2019

TNFAIP2 (TNF-α-inducible protein 2) is identified as an angiogenic and proinflammatory factor and is essential for formation of tunneling nanotubes connecting between remote cells. Cancer-associated TNFAIP2 overexpression is first demonstrated in nasopharyngeal carcinoma (NPC) and is significantly correlated with poor survival of patients. We previously revealed that TNFAIP2 is associated with actin filaments, inducing actin remodeling and membrane protrusion and promotes cell motility of NPC cells. To elucidate functional roles of TNFAIP2 in cancer progression, we exploited co-immunoprecipitation (co-IP) coupled with mass spectrometry (MS)-based proteomic analysis to identify interacting proteins of TNFAIP2 in NPC cells. Epidermal growth factor (EGF) receptor (EGFR) is one of the identified candidates and is frequently overexpressed in various cancer types. We validated the interaction between TNFAIP2 and EGFR in two types of NPC cell lines; nevertheless, the interaction of TNFAIP2 with EGFR was reduced along with EGF stimulation. Reciprocal domain mapping analyses and immunofluorescence staining further demonstrated that the C-terminal amino acid residues 461-520 of TNFAIP2, which are dispensable for its association with the plasma membrane, are required for TNFAIP2 interaction with EGFR. On the other hand, the intracellular juxtamembrane domain (amino acids 645-689) and kinase domain (amino acids 690-945) of EGFR are needed for its interaction with TNFAIP2. Furthermore, EGF-triggered internalization of EGFR was significantly interfered in TNFAIP2-knockout NPC cells generated using the CRISPR-Cas9 system, accompanied by alleviated auto-phosphorylation of EGFR on the 1068 and 1173 tyrosine residues and subsequent activation of downstream ERK1/2. This impairment of liganded EGFR-transduced signaling in TNFAIP2-knockout NPC cells was correlated with a decrease in cell migration as revealed by transwell migration assays. These data collectively reveal a novel role of TNFAIP2 in modulation of EGF-triggered EGFR activation and sequential signaling transduction through protein-protein interactions. Efforts are made to pursue if the aforementioned events involve modulation of EGFR oligomerization or recruitment of internalized activated EGFR into endosomes. The results could shed light on how TNFAIP2 promotes cancer progression via coordinating with EGFR and the impact of TNFAIP2 on EGFR-targeted cancer therapy.

Citation Format: Hao-Ping Liu, Chih-Ching Wu. TNFAIP2 interacts with EGFR to modulate EGF-induced EGFR auto-phosphorylation and internalization and sequential ERK1/2 activation in nasopharyngeal carcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2643.
Abstract 2659: IRE1á-dependent increase of Gá12, a gep oncogene, augments ER stress-induced catastrophic cell death
Authors: Tak Jihoon , Kim Tae Hyun , Kim Sang Geon
Published: August 2019

Hepatocellular carcinoma (HCC) belongs to the most deadly types of cancer since it has a poor prognosis due to its aggressive metastatic phenotype. Endoplasmic reticulum (ER) stress is closely associated with the incidences of a variety of liver diseases including liver injury, regeneration, fibrosis, cirrhosis and often HCC. G protein-coupled receptor (GPCR) signals lead to activation of their downstream pathways through G proteins. Previously, we reported that Gα12 overexpression enhances HCC malignancy, promoting cancer migration and microvascular invasion. However, the role of Gα12 in ER stress-associated pathophysiology in the liver was unclear. Given the link between ER stress and HCC malignancy, this study investigated the effect of ER stress on Gα12, the role of Gα12 in ER stress-mediated hepatocyte death, and the underlying pathway. In the analyses of RNA-sequencing data from mouse liver or primary mouse embryonic fibroblasts challenged with ER stress, Gα12 and C/EBP homologous protein (CHOP) levels correlated with each other. Increases in Gα12 level by unfolded protein response (UPR) under ER stress condition was verified using primary hepatocytes or hepatocyte-derived cell line, confirmative of the close association between Gα12 and UPR. Of note, enforced Gα12 expression under ER stress condition augmented IRE1α level in a RhoA/Rock-dependent pathway. Among the canonical pathways, IRE1α gene silencing distinctly inhibited Gα12 induction elicited by ER stress in hepatocytes. Consistently, overexpression of IRE1α enhanced Gα12 level upon tunicamycin treatment. Similar outcomes were obtained in cells or mice treated with acetaminophen, a representative liver toxicant inducing ER stress response. Overall, our results provide evidence that IRE1α-dependent increase of Gα12 potentiates ER stress response in the liver as mediated by the RhoA-ROCK pathway, enhancing catastrophic death of hepatocytes.

Citation Format: Jihoon Tak, Tae Hyun Kim, Sang Geon Kim. IRE1á-dependent increase of Gá12, a gep oncogene, augments ER stress-induced catastrophic cell death [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2659.
Abstract 2665: Zinc dysregulation as an emerging molecular target in epithelial cancers
Authors: Perer Jessica , Justiniano Rebecca , Hua Anh , Wondrak Georg T.
Published: August 2019

Zinc plays an established role in structure and function of enzymes and transcription factors, and zinc signaling has now been recognized as a molecular determinant of epithelial differentiation and cell fate. Intracellular zinc homeostasis is regulated by zinc importers (ZIPs encoded by the SLC39A gene family). Cumulative evidence suggests that dysruption of zinc homeostasis is an emerging hallmark of various tumor types, characterized by downregulation of ZIP expression upstream of intracellular zinc depletion. In nonmelanoma skin cancer (NMSC) examined in TMA format we have observed downregulation of ZIP2 (involved in epidermal differentiation) that occurs with zinc depletion and impaired differentiation. Likewise, in pancreatic ductal adenocarcinoma (PDAC) tumor tissue, downregulation of ZIP3 and zinc depletion are detectable. We therefore tested feasibility of pharmacological induction of intracellular zinc overload for chemotherapeutic intervention. Using the small molecule ionophore ZnPT (zinc pyrithione) as an experimental chemotherapeutic, rapid induction of zinc overload followed by metal stress response signaling and cell death were observable in a panel of malignant epithelial cell lines (NMSC: SCC-25; HaCaT-ras II-4; PDAC: BxPC-3, MIA PaCa-2, PANC-1). Remarkably, PDAC cell lines displayed nanomolar sensitivity to ZnPT-induced cytotoxicity. In BxPC-3 cells, pronounced upregulation of stress response gene expression (MT2A, HSPA6, HMOX1) and signaling (p-p38, p-eIF2α, HO-1) was detectable within one hour of ZnPT exposure. Accumulation of protein-ubiquitin conjugates further substantiated the rapid occurrence of ZnPT-induced proteotoxic stress and UPR, consistent with a role of ZnPT in the inhibition of proteasome-associated deubiquitinating enzymes (DUBs). Next, we confirmed NMSC-directed anti-tumor activity of ZnPT in a photocarcinogenesis SKH1 mouse model, followed by exploratory chemotherapeutic intervention targeting BxPC-3 PDAC xenografts. Taken together, our data suggest that ZIP-based dysruption of intracellular zinc homeostasis may be a valid molecular target in specific epithelial cancers. [This research was funded in part by NCI: P30 CA023074 & R03 CA230949.]

Citation Format: Jessica Perer, Rebecca Justiniano, Anh Hua, Georg T. Wondrak. Zinc dysregulation as an emerging molecular target in epithelial cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2665.
Abstract 2694: A first-in-class small-molecule modulator of the p300/CBP interactome exhibits broad efficacy in xenograft models of solid tumors and hematologic malignancies
Authors: Hentsch Bernd , Cattori Valentino , Labelle Marc , Kessler Ulrich
Published: August 2019

Background: Dysregulation of the cellular transcription machinery is a fundamental feature of cancer. E1A binding protein (p300) and CREB binding protein (CBP) are two closely related paralog transcription co-activators involved in the expression of oncogenic drivers in cancer cells.

Methods: Small molecule ligands of the CH1/TAZ1 domain of p300/CBP were rationally designed and optimized for their anti-proliferative activity in vitro. Subsequent characterization focused on their ability to modulate downstream biological processes controlled by p300/CBP, including hormone-dependent androgen receptor signalling, the HIF-1 alpha/VEGF pathway and reactivation of p53 in HPV-positive carcinomas.

The in vivo efficacy of this novel compound class was assessed in a variety of patient and cell line derived xenograft models, and pharmacodynamic effects were investigated.

Results: Several modulators of p300/CBP exhibited anti-proliferative effects at low nanomolar concentrations in more than 60 cancer cell lines inducing both senescence and apoptosis in a highly context dependent manner. Transcriptome analyses revealed the downregulation of various drivers of cell cycle progression.

Once daily oral administration triggered strong growth-inhibitory effects in several xenograft models up to complete tumor eradication at well tolerated doses. p300/CBP dependent biomarkers like VEGF (colon cancer) and PSA (prostate cancer) were significantly downregulated in the tumors of treated animals. In an orthotopic model of acute myeloid leukemia, the growth of primary tumors and metastasis was almost completely inhibited.

Conclusions: Reprogramming the transcriptional profile of cancer cells by modulation of p300/CBP activity by targeting the CH1/TAZ1 domain represents a novel and broadly applicable approach for the treatment of cancer. The presented data illustrate the clinical potential of this new class of therapeutics against a broad variety of tumor types, including prostate and colon cancer as well as hematological malignancies.

Citation Format: Bernd Hentsch, Valentino Cattori, Marc Labelle, Ulrich Kessler. A first-in-class small-molecule modulator of the p300/CBP interactome exhibits broad efficacy in xenograft models of solid tumors and hematologic malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2694.
Abstract 2701: Functionally specialized subsets of exhausted CD8+ T cells mediate tumor control and differentially respond to checkpoint blockade
Authors: Miller Brian C. , Sen Debattama R. , Abosy Rose Al , Bi Kevin , Virkud Yamini V. , LaFleur Martin W. , Yates Kathleen B. , Lako Ana , Felt Kristen , Naik Girish S. , Manos Michael , Gjini Evisa , Hodi F. Stephen , Rodig Scott J. , Sharpe Arlene H. , Haining W. Nicholas
Published: August 2019

T cell dysfunction in the tumor microenvironment (TME) is a hallmark of many cancers. Reinvigoration of T cell function by PD-1 checkpoint blockade can result in striking clinical responses, but is only effective in a minority of patients. The basis for T cell dysfunction in the TME, as well as the mechanisms by which anti-PD-1 therapy acts on dysfunctional T cells are not fully understood. Here we show that anti-PD-1 therapy acts on a specific subpopulation of CD8+ tumor-infiltrating lymphocytes (TILs) in melanoma mouse models, which can also be found in patients with melanoma. We find that dysfunctional CD8+ TILs possess canonical epigenetic and transcriptional features of T cell exhaustion, mirroring those seen in chronic viral infection. Similar to chronic viral infection, exhausted CD8+ TILs contain a subpopulation of “progenitor exhausted” T cells that have a distinct regulatory state. Progenitor exhausted TILs also have critical functional attributes that are not shared by the majority “terminally exhausted” TILs: they retain more polyfunctionality, persist following transfer into tumor-bearing mice, and differentiate to repopulate terminally exhausted TILs in the TME. As a result, progenitor exhausted CD8+ TILs are better able to control tumor growth than terminally exhausted cells. Progenitor exhausted, but not terminally exhausted, CD8+ TILs can respond to anti-PD-1 therapy but this occurs without reversion of their exhausted epigenetic state. Human melanomas contain CD8+ T cells with a progenitor exhausted phenotype and patients with a higher fraction of this subpopulation in their tumors have a significantly longer duration of response to combination checkpoint blockade therapy. Therefore, approaches to expand progenitor exhausted CD8+ T cells in the tumor microenvironment may be an important component of improving checkpoint blockade response.

Citation Format: Brian C. Miller, Debattama R. Sen, Rose Al Abosy, Kevin Bi, Yamini V. Virkud, Martin W. LaFleur, Kathleen B. Yates, Ana Lako, Kristen Felt, Girish S. Naik, Michael Manos, Evisa Gjini, F. Stephen Hodi, Scott J. Rodig, Arlene H. Sharpe, W. Nicholas Haining. Functionally specialized subsets of exhausted CD8+ T cells mediate tumor control and differentially respond to checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2701.
Abstract 2726: Functional multiomic profiling identifies Aurora kinase inhibition as a therapeutic strategy in RIT1-mutant lung adenocarcinoma
Authors: Vichas Athea , Nkinsi Naomi T. , Berger Alice
Published: August 2019

Treatment of lung cancer is evolving from standard cytotoxic to personalized treatment based on the molecular alterations unique to each patient’s tumor. In our recent work with TCGA and others, we identified somatic mutations in the gene encoding the RAS-related small GTPase, RIT1, in lung adenocarcinomas. In addition, somatic RIT1 mutations have also been identified in myeloid malignancies and germline RIT1 mutations are found in the developmental “RAS-opathy,” Noonan syndrome. In all these diseases, RIT1 mutations are mutually-exclusive with other RAS/MAPK pathway mutations, including mutations in EGFR, KRAS, and ALK. While our previous work demonstrated that gain-of-function RIT1 mutations induce activation of PI3K and MEK signaling, the specific effectors used by RIT1 to promote tumorigenesis are unknown. To genetically dissect the signaling pathways downstream of RIT1, KRAS, EGFR, and PIK3CA, we performed genome-wide CRISPR/Cas9 screens in four isogenic lung adenocarcinoma cell lines in which cell survival is dependent on the expression of the oncogene. Through integrative analysis of essential genes across the four cell lines, we identified synthetic lethal relationships unique and shared in each isogenic background. Among the dependencies identified was the requirement of aurora kinase pathway genes for survival of RIT1-mutant cells, raising the possibility of therapeutic aurora kinase inhibition in RIT1-positive tumors. To evaluate whether the dependence on Aurora kinases extended to small molecule inhibition, we performed a screen of 160 small molecules in clinical development or approved by the FDA. Consistent with our CRISPR/Cas9 results, we find that RIT1-mutant cells depend on Aurora kinase activity for survival. Interestingly, global phosphoproteomic profiling identified RIT1 regulation of an Aurora kinase-Haspin axis. Taken together these results identify a new arm of RIT1 signaling and nominate Aurora kinase inhibition as a potential therapeutic strategy in RIT1-mutated tumors.

Citation Format: Athea Vichas, Naomi T. Nkinsi, Alice Berger. Functional multiomic profiling identifies Aurora kinase inhibition as a therapeutic strategy in RIT1-mutant lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2726.
Abstract 2732: Frameshift neoantigen vaccination prevent Lynch syndrome mouse model intestinal cancer
Authors: Gelincik Ozkan , Ibrahim Hamza , Ozkan Mine , Ahadova Aysel , Sei Shizuko , Shoemaker Robert , Kloor Mattias , Doeberitz Magnus Von Knebel , Lipkin Steven M.
Published: August 2019

Microsatellite-unstable (MSI) cancers occurring in the context of Lynch syndrome elicit pronounced tumor-specific immune responses directed against frameshift peptide (FSP) neoantigens, which result from mismatch repair (MMR) deficiency-induced insertion/deletion mutations in coding microsatellites (cMS). We have recently completed a clinical phase I/IIa trial that successfully demonstrated safety and immunogenicity of an FSP neoantigen-based vaccine in MSI colorectal cancer patients (Clinical trial number: NCT01461148). The vaccine was safe and induced robust cellular and humoral immune responses in all vaccinated patients. To further develop a cancer preventive vaccine against MSI cancers in Lynch syndrome, we aimed to establish a preclinical mouse model. A systematic database search was performed to identify cMS sequences in the murine genome. Subsequently, intestinal tumors obtained from Lynch syndrome mice (Msh2flox/flox VpC+/+) were evaluated for mutations affecting these candidate microsatellites. Thirteen candidate cMS were detected that presented with a mutation frequency of 15% or higher. Epitope prediction using the netMHC4.0 algorithm was performed, and ten most promising FSP neoantigens were synthesized. Immunogenicity was evaluated after vaccination of C57BL/6 mice using IFN-gamma ELISpot. Four FSP neoantigens derived from cMS mutations in the genes Nacad, Maz, Xirp1, and Senp6 elicited strong antigen-specific cellular immune responses. CD4-specific T cell responses were detected for Maz, Nacad, and Senp6 and CD8-positive T cells were detected for Xirp1 and Nacad. Vaccination with peptides encoding these four intestinal cancer FSP neoantigens promoted anti-neoantigen immunity, reduced intestinal tumorigenicity and prolonged overall survival (P<0.01). Additionally, NSAIDs, which have chemopreventive efficacy for Lynch syndrome, increase T cell immunity against neoantigens. Mechanistic tumor mutation burden and adaptive immune response studies will be shown. In summary, these data support the further development of vaccination strategies for preventing cancers associated with Lynch syndrome.

Citation Format: Ozkan Gelincik, Hamza Ibrahim, Mine Ozkan, Aysel Ahadova, Shizuko Sei, Robert Shoemaker, Mattias Kloor, Magnus Von Knebel Doeberitz, Steven M. Lipkin. Frameshift neoantigen vaccination prevent Lynch syndrome mouse model intestinal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2732.
Abstract 2759: Chemoproteomic profiling of the oncometabolite fumarate
Authors: Bergholtz Sarah E. , Briney Chloe A. , Kulkarni Rhushikesh A. , Wei David , Bak Daniel W. , Shrimp Jonathan H. , Weerapana Eranthie , Linehan W. Marston , Meier Jordan L.
Published: August 2019

Dysregulated metabolism is a feature of many diseases, including cancer. In addition to providing energy and building blocks to growing cells, altered metabolism can assist in tumor growth by producing “oncometabolites”. For example, in hereditary leiomyomatosis and renal cell carcinoma (HLRCC) inactivating mutations in fumarate hydratase (FH) leads to accumulation of millimolar levels of an oncometabolite, fumarate. At such high concentrations, fumarate can spontaneously react with protein cysteine residues leading to a post-translational modification (PTM) called cysteine succination. This PTM can directly stimulate tumorigenic signaling, however, current methods to study this PTM are limited. Our lab has developed chemical proteomic methods to investigate proteome-wide targets of cysteine succination. Using these methods, we have identified hundreds of targets of fumarate in normal kidney cells as well as HLRCC cells. One interesting target identified that has implications in cancer progression is SMARCC1, a core subunit of a nucleosome remodeling complex known as the SWI/SNF complex. The SWI/SNF complex is a well-known tumor suppressor and mutation of this complex leads to cancer development. We have demonstrated that excess fumarate levels result in hyper-modification of SMARCC1 and decrease in SWI/SNF complex stability. This instability also results in an increase in EZH2 expression as well as activity, and an increase in H3K27Me3. Our current efforts are aimed at understanding how fumarate affects the function of this complex in vivo and exploring the potential of using EZH2 inhibitors in the treatment of HLRCC.

Citation Format: Sarah E. Bergholtz, Chloe A. Briney, Rhushikesh A. Kulkarni, David Wei, Daniel W. Bak, Jonathan H. Shrimp, Eranthie Weerapana, W. Marston Linehan, Jordan L. Meier. Chemoproteomic profiling of the oncometabolite fumarate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2759.
Abstract 2764A: Elucidating the pharmacological effects of covalent microtubule stabilizing taccalonolides through functional tagging
Authors: Yee Samantha S. , Du Lin , Risinger April L.
Published: August 2019

Microtubule stabilizing taxanes are highly effective in the treatment of solid tumors and continue to be used as single agents and in combination with targeted therapies and immunotherapies. However, limitations of taxane therapy include acquired and inherent drug resistance. The taccalonolides are a novel class of microtubule stabilizers that circumvent clinically relevant forms of drug resistance to the taxanes in vitro and in vivo. The taccalonolides are efficacious in taxane-resistant models due to their distinct mechanism of microtubule stabilization that involves covalent binding to β-tubulin. Pharmacological studies of the taccalonolides have been complicated by their irreversible binding to tubulin. A functional tagged taccalonolide would facilitate a greater understanding of the pharmacological, cellular, and physiological effects of this novel drug class. We have generated and characterized a series of fluorescently tagged taccalonolides that retain microtubule binding and stabilizing activities to serve as functional pharmacological taccalonolide probes. Biochemical tubulin polymerization, live cell fluorescence, immunofluorescence imaging, and the sulforhodamine B cytotoxicity assay were conducted to evaluate the microtubule binding and stabilizing effects of these taccalonolide probes. We identified stable taccalonolide probes that retain the biological activities of untagged taccalonolides and facilitate their detection in live cells and in cell lysates. The rates of taccalonolide uptake and tubulin binding in cells, tumors, and normal tissues were determined. These studies have also allowed for an evaluation of the anatomical distribution of the taccalonolides in vivo, which can inform on their potential for antitumor efficacy in distinct tumor sites. Furthermore, we have generated a cellular model to evaluate the kinetics of taccalonolide binding to β-tubulin mutants that are predicted to influence drug binding based on the crystal structure. These studies have confirmed the covalent interaction between the taccalonolides and D224 on β-tubulin and informed on other residues critical for drug binding. The generation of a functional tagged taccalonolide will continue to be a valuable tool in evaluating the pharmacokinetics of these agents and inform on drug targeting strategies that will facilitate their clinical development.

Citation Format: Samantha S. Yee, Lin Du, April L. Risinger. Elucidating the pharmacological effects of covalent microtubule stabilizing taccalonolides through functional tagging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2764A.