bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2414: Fibromodulin expression in human prostate cancer tissue: Implications for prostate cancer progression
Authors: Padron Estebana Ines Benedetti , Marzo Angelo De , Valle Javier Baena Del , Geliebter Jan , Reyes Niradiz
Published: July 2017

Background: Fibromodulin is a small leucine-rich proteoglycan important for extracellular matrix organization and essential for tissue repair in multiple organs. Recently, differential expression of fibromodulin has been shown in human prostate cancer cell lines with different cancer phenotypes and in human prostate cancer tissue compared to normal/benign tissue.

Methods: The protein expression level of fibromodulin was analyzed by immunohistochemistry using a prostate tissue microarray (TMA), constructed from archival radical prostatectomy and trans-urethral prostatectomy tissue specimens, from patients with localized prostate cancer (PCa). Stained sections from the donor blocks were evaluated, and a representative area from PCa, high grade prostatic intraepithelial neoplasia (HGPIN), proliferative inflammatory atrophy (PIA), and benign prostate tissue (BPT) was included into the TMA. Staining for each lesion was scored, using H-score, by microscopic assessment of the percentage of epithelial cells with positive staining. H-score values were compared between groups by ANOVA test, and p < 0.05 was considered statistically significant. The Ethical Review Board of the academic institution approved this study.

Results: Fibromodulin expression at protein level was evaluated in 378 cores representing PCa (143 cores), HGPIN (58), PIA (102), and BPT (78). Mean fibromodulin expression in cores with PCa, HGPIN, and PIA was significantly higher than mean of fibromodulin expression in normal glands (p<0.0001). There was a higher mean staining score in PCa (156, 95% CI:144–167), compared to HGPIN (131.4, 95% CI:109-153), PIA (128, 95% CI:117-138), and BPT (33.3, 95% CI:27-38). Thus, fibromodulin expression increased across the PCa progression model.

Conclusions: The expression pattern of fibromodulin showed a significant increase from benign prostate tissue through pre-cancerous lesions to PCa. These findings suggest that this proteoglycan may be involved in the process of prostate cancer progression, with low levels in pre-cancerous lesions and higher levels in cancer tissue. Additional studies are required to determine the biological role and potential clinical implications of fibromodulin in prostate cancer.

Citation Format: Estebana Ines Benedetti Padron, Angelo De Marzo, Javier Baena Del Valle, Jan Geliebter, Niradiz Reyes. Fibromodulin expression in human prostate cancer tissue: Implications for prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2414. doi:10.1158/1538-7445.AM2017-2414
Abstract 2415: Genome-wide alterations in gene expression of prostate cancer (PC) cells surviving neo-adjuvant androgen deprivation therapy
Authors: Ferrari Anna C. , Sabaawy Hatem , Stein Mark , Foran David , Chen Ying , Yegnasubramanian Srinivasan
Published: July 2017

Background: Although androgen deprivation therapy initially decreases PC tumor burden, resistance to further androgen receptor (AR)-directed treatments or chemotherapy is inevitable once CRPC is established. We postulated that the stress of ADT triggers widespread alterations in expression that renders a metastable physiologic state conditioned by epigenetic changes that might be initially reversible by targeting non-androgen pathways. We conducted a pilot study to explore genome-wide expression alterations in PC foci surviving 3 months ADT (eADT).

Methods: mRNA from 7 frozen microdissected PC foci and normal counterparts (NC) were processed for RNA-seq. RNA-seq changes in eADT specimens were compared first with NC and the untreated PC in the TCGA PRAD (TCGA) database to castrate resistant (mCRPC) specimens in the dbGAP study phs000915.v1.p1database. The raw data (fastq files) was quantified using kallisto, normalized by TMM using R package edgeR, batch effects corrected using R package SVA. Analysis of differential gene expression by R package sleuth. Pathway and gene set by GSEA, GAGE/pathview packages for Gene Ontology (GO) and KEGG.

Results: TMPRSS2-ERG+, 5/7. Highest DEG in eADT vs. TCGA vs mCRPC were non-coding RNA’s. Among 17431 differentially regulated paths; GSEA of eADT vs TCGA or mCRPC: 341 (1.95%) and 1366 (7.84%) up- vs 46 (0.26%) and 59 (0.34%) down-regulated. KEGG paths, eADT vs. TCGA or mCRPC, 11 and 53 up vs. 2 and 3 down- respectively. Highly down- path in eADT vs TCGA (log q<10-17) was ribosomal vs. cell cycle and DNA replication in mCRPC. Six paths significantly up- in eADT vs TCGA or mCRPC: Wnt, adherence junction, steroid biosynthesis, unsaturated fatty acids, citrate cycle, ErbB. Calcium, MAPK, insulin, GnRH and Hedgehog were also up- in eADT vs mCRPC. AR full-length was marginally higher in eADT than TCGA and lower than mCRPC, no differences in gene targets.

Conclusions: This pilot data shows that ADT triggers a wide range of gene expression alterations that support PC cell survival and may be vulnerable to therapeutic targeting in addition to the androgen pathway. Validation of these findings is planned in a larger set of samples from the same bank.

Citation Format: Anna C. Ferrari, Hatem Sabaawy, Mark Stein, David Foran, Ying Chen, Srinivasan Yegnasubramanian. Genome-wide alterations in gene expression of prostate cancer (PC) cells surviving neo-adjuvant androgen deprivation therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2415. doi:10.1158/1538-7445.AM2017-2415
Abstract 2430: The expression of BCL6 and ZEB family transcription factors and their correlation in breast cancers
Authors: Zhao Min , Ang Lin , Zheng Li , Wang Jin , Huang Jin , Hu Hongguang , Zou Qiang
Published: July 2017

The proto-oncogene B-cell lymphoma 6 (BCL6) is an evolutionarily conserved zinc finger protein and a potent transcriptional repressor. It is also the master regulator of B-lymphocyte development. Emerging evidence indicates that BCL6 may play an important role in breast cancer progression. In this study, we investigated the expression of BCL6 and tis correlation with the expression of epithelial-mesenchymal transition (EMT)-associated transcription factors zinc finger E-box-binding homeobox 1 (ZEB1) and ZEB2 in invasive breast cancers. The mRNA and protein expression of BCL6, ZEB1 and ZEB2 were examined using in situ hybridization and immunohistochemistry, respectively, in 228 breast cancer patients and 80 patients with breast benign diseases. The association of BCL6, ZEB1 and ZEB2 expression with clinicopathological parameters and patient survival were analyzed. We found that the expression of BCL6, ZEB1 and ZEB2 protein and mRNA were significantly higher in breast cancer tissues than in breast benign disease tissues (P<0.05). The expression levels of BCL6, ZEB1 and ZEB2 were all positively correlated with the tumor size, lymph node metastasis and higher tumor stages (P<0.05). Furthermore, patients with BCL6, ZEB1 and ZEB2 protein-positive primary tumors were associated with a significant lower overall survival (OS) rate (P=0.001, 0.002 and 0.001, respectively) and post-operative relapse-free survival (RFS) rate (P=0.002, 0.001 and 0.003 for the expression of BCL6, ZEB1 and ZEB2, respectively). The mRNA expression of ZEB1 and ZEB2 were positively correlated with BCL6 mRNA expression (rs=0.326, P<0.001; and rs=0.382, P<0.001, respectively); the protein expression of ZEB1 and ZEB2 were also positively correlated with BCL6 protein expression (rs=0.449, P<0.001; and rs=0.669, P<0.001, respectively). These results indicate that BCL6, ZEB1 and ZEB2 may be as potential biomarkers for predicting invasion, metastasis and prognosis of breast cancer and that BCL6 may be a regulator of ZEB family transcription factors (ZEB1 and ZEB2).

Note: This abstract was not presented at the meeting.

Citation Format: Min Zhao, Lin Ang, Li Zheng, Jin Wang, Jin Huang, Hongguang Hu, Qiang Zou. The expression of BCL6 and ZEB family transcription factors and their correlation in breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2430. doi:10.1158/1538-7445.AM2017-2430
Abstract 2431: Single cell gene expression profiling in breast cancer cells with the Her2/neu gene knockout by CRISPR-Cas9
Authors: Wang Xiaoyang , Lomas Chip , Tycon Michael A. , Betts Craig , Weaver Suzanne
Published: July 2017

The Her2/neu gene is amplified and overexpressed in 15%-30% of breast cancers. The overexpression of this oncogene is strongly correlated with decreased survival, increased cancer relapse, and poor prognosis. Although therapy has been successfully developed to target this oncogene, a better understanding of this oncogene will provide further insight for breast cancer biology and future drug development. In recent years, the CRISPR-Cas9 system has emerged as an efficient method for genetic engineering, enabling targeted gene knockout with minimal off-target effects.

In this study, we employed a plasmid-based CRISPR-Cas9 system to knock out the Her2/neu gene in breast cancer cells. Puromycin selected, GFP-positive (two indicators of the incorporation of the CRISPR-Cas9 system), Her2-negative individual cells were index-sorted using a BD FACSMelody™ system into individual wells of a 96-well BD™ Precise plate with sample barcoding and molecular indexing. A whole transcriptome amplification (WTA) assay was performed to obtain a gene expression profile for each of the Her2/neu knockout cells. Her2 gene knockout was performed on two cell lines: T47D, a ductal carcinoma-derived breast cancer cell line with no Her2 amplification that shows low to intermediate Her2/neu expression; and SKBR3, an adenocarcinoma-derived breast cancer cell line known for Her2/neu gene amplification and overexpression. For comparison, WTA assays were also carried out on parental cells without gene editing. Comparison of the gene expression profiles reveals downstream changes in gene expression correlated to the Her2 knockout.

The profiling of gene expression in Her2/neu CRISPR-Cas9 knockout cells on a single cell level promises to provide insight into the mechanisms in these aggressive cancers that could help future drug discovery.

For Research Use Only. Not for use in diagnostic or therapeutic procedures.

23-19341-00

Citation Format: Xiaoyang Wang, Chip Lomas, Michael A. Tycon, Craig Betts, Suzanne Weaver. Single cell gene expression profiling in breast cancer cells with the Her2/neu gene knockout by CRISPR-Cas9 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2431. doi:10.1158/1538-7445.AM2017-2431
Abstract 2435: Smoothened a new perspective for uterine leiomyoma treatment
Authors: Garcia Natalia , Anjos Laura Gonzalez , Maffazioli Giovana De Nardo , Bozzini Nilo , Baracat Edmund Chada , Carvalho Katia Candido
Published: July 2017

Background: Uterine leiomyomas (LM) are the most common gynecologic tumors occurring in women of reproductive age. Patients may present clinical complications such as bleeding, pain and infertility. Additionally, some researchers believe that a leiomyosarcoma can arise from a degenerated LM. Efficient treatments for LM are still limited. Identification of gene markers can help to elucidate these tumors pathogenesis and to reveal molecules that can be used as therapeutic targets.

Objective: To assess gene and miRNAs expression, and DNA methylation profiles of genes related to the Sonic Hedgehog (SHH) signaling pathway in uterine leiomyoma samples in order to look for potential therapeutic targets.

Methods: 80 samples of LM and 20 myometrium (MM) were obtained in the Department of Obstetrics and Gynecology at HCFMUSP/Sao Paulo - Brazil. Expression profile of 106 genes and 84 miRNAs sequences related to SHH regulation, and the percentage of methylation in the promoter region of the SHH, PTCH1, SMO, SUFU, GLI and GLI3 genes were performed by quantitative Real Time PCR. Results: Among 106 genes evaluated, 16 showed hyper- and 11 showed hypoexpression in LM samples, compared to MM. Only SMOOTHENED (SMO) was found hyperegulated in LM. miRNAs analysis showed 16 sequences with different regulation profiles between LM and MM. None of them is involved in the regulation of SMO expression. DNA methylation profile showed a higher percentage of methylation in LM samples, but this difference did not exceed 2% of methylation for the PTCH1, SMO, GLI1 and GLI3 genes. Conclusion: Our results suggest an activation of SHH pathway in LMs by hyperexpression of SMO. These results are very interesting because there are SMO specific drugs approved by FDA for other tumors types.

Citation Format: Natalia Garcia, Laura Gonzalez Anjos, Giovana De Nardo Maffazioli, Nilo Bozzini, Edmund Chada Baracat, Katia Candido Carvalho. Smoothened a new perspective for uterine leiomyoma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2435. doi:10.1158/1538-7445.AM2017-2435
Abstract 2453: Chromatin remodeling genes are frequently somatically altered in cervical carcinomas
Authors: Ojesina Akinyemi , Sundaresan Aishwarya , Srinivasasainagendra Vinodh , Tiwari Hemant , Huh Warner
Published: July 2017

Introduction: Cervical cancer is responsible for 15% of all deaths due to cancer in women worldwide. There is a need to identify somatic mutations driving this cancer in order to facilitate development of novel therapeutic strategies.

Experimental procedures: We analyzed whole exome sequencing data from 430 cervical carcinomas. The data were derived from a combination of our previously published work (Ojesina et al. Nature 2014; Chung et al, Int J Cancer 2015), and publicly available data generated by the Cancer Genome Atlas (TCGA). The Mutect2.0 and MutSig2CV algorithms were used to identify somatic mutations and significantly mutated genes (SMGs) respectively. Copy number alterations were analyzed using the GISTIC algorithm.

Findings: Based on MutSig2CV false discovery rate threshold of 0.1, we identified MLL3 (19%) and MLL2 (13%) as novel significantly mutated genes (SMGs) in cervical cancer. In addition, other chromatin modifying genes including EP300 (12%) and ARID1A (7%) were confirmed as SMGs. Further investigation of genes that did not meet the threshold revealed that 228 of 430 (53%) of cervical tumors harbored at least one somatic mutation in a chromatin modifying gene. These include genes in the myeloid/lymphoid or mixed-lineage leukemia (MLL) family (28%), lysine (K)-specific demethylase (KDM) family (23%), AT rich interactive domain (ARID) family (13%), SWI/SNF related, matrix associated, actin dependent regulator of chromatin (SMARC) family (8%) and histone cluster 1 (HIST1) family (4%).

Conclusions: We have demonstrated that a majority of cervical cancers harbor somatic mutations in chromatin remodeling genes. This novel finding was facilitated by the larger sample size derived from combining multiple datasets, and may have diagnostic and therapeutic implications in cervical cancer.

Citation Format: Akinyemi Ojesina, Aishwarya Sundaresan, Vinodh Srinivasasainagendra, Hemant Tiwari, Warner Huh. Chromatin remodeling genes are frequently somatically altered in cervical carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2453. doi:10.1158/1538-7445.AM2017-2453
Abstract 2455: Human glioblastoma arises from the distant subventricular zone normal appearing but harboring tumor-initiating mutations
Authors: Lee Joo Ho , Lee Jeong Eun , Kahng Jee Ye , Park Junseong , Yoon Seon Jin , Kim Se Hoon , Chang Jong Hee , Kang Seok-Gu , Lee Jeong Ho
Published: July 2017

Glioblastoma multiforme (GBM) is the most devastating and incurable brain tumor. Although the identification of cells with tumor initiating mutations or their location can provide the fundamental basis for understanding disease progression, the origin of GBM remains controversial due to the lack of direct evidence in human GBM patients. Here, we performed ultra-deep sequencing of triple-matched tissues of i) radiologically and pathologically normal subventricular zone (SVZ), which is distant from tumor, ii) GBM tumor, and iii) blood (or normal cortical tissues) from patients with GBM (IDH-wildtype), compared to those with other type of brain tumors such as GBM (IDH-mutant), meningioma, oligodendrgolioma, metastatic brain tumor, and GBM (IDH-wildtype) with SVZ-invasion. Surprisingly, we found that in 55.5% of IDH-WT GBM patients (5 of 9), normal appearing and distant SVZ already contained the low level of GBM mutations such as TP53, EGFR, RB1, PDGRF or TERT variations observed in the matched tumor. Single cell sequencing of GBM tumors and laser capture microdissection analysis of the SVZ show that mutations are enriched in the astrocyte ribbon area, which clonally evolved from the SVZ to the distant GBM tumor. Furthermore, using CRISPR-Cas9 system in the postnatal mouse brain, we showed that neural stem cells with TP53, PTEN, EGFR mutations migrated away from the mutated SVZ site and then formed the high grade malignant glioma in the distant cortical region. Taken together, this study provides the direct evidence that human glioblastoma arises from the distant SVZ that is normal-appearing but harboring tumor-initiating mutations.

Citation Format: Joo Ho Lee, Jeong Eun Lee, Jee Ye Kahng, Junseong Park, Seon Jin Yoon, Se Hoon Kim, Jong Hee Chang, Seok-Gu Kang, Jeong Ho Lee. Human glioblastoma arises from the distant subventricular zone normal appearing but harboring tumor-initiating mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2455. doi:10.1158/1538-7445.AM2017-2455
Abstract 2468: Gene aberrations for precision medicine against lung adenocarcinoma
Authors: Saito Motonobu , Kono Koji , Kohno Takashi
Published: July 2017

Lung adenocarcinoma (LADC) is often triggered by an aberration in a driver oncogene. LADC harboring EGFR mutation and ALK fusion can be treated with anti-cancer drugs that target the aberrant gene products. These molecularly targeted drugs showed significant positive effectiveness for the LADC patients with EGFR mutations and ALK fusions. Additional oncogene aberrations, including RET, ROS1, and NRG1 fusions, skipping of exon 14 of MET, and mutations in BRAF, HER2, NF1, and MEK1, were recently added to the list of such “druggable” driver oncogene aberrations, and their responses to targeted therapies are currently being evaluated in several clinical trials. On the other hand, about 30% and 50% of LADCs in patients in Japan and Europe/USA, respectively, lack the driver oncogene aberrations listed above. Therefore, novel therapeutic strategies, such as those that exploit the vulnerabilities of cancer cells with non-oncogene aberrations, are urgently required. In this presentation, we show gene mutation profiles according to driver oncogenes and summarize the frequencies of those aberrations. We also compare driver aberrations between Japan and USA according to smoking status and sex. This will provide the current status of research on precision medicine against LADC and enumerates the research priorities for the near future.

Citation Format: Motonobu Saito, Koji Kono, Takashi Kohno. Gene aberrations for precision medicine against lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2468. doi:10.1158/1538-7445.AM2017-2468
Abstract 2474: The mechanistic role of polyamines in DNA double-strand break repair
Authors: Lee Chih-Ying , Su Guan-Chin , Ko Min-Yu , Huang Wen-Yen , Chang Geen-Dong , Lin Sung-Jan , Chi Peter
Published: July 2017

Polyamines are essential organic cations for cell growth, proliferation and tissue remodeling. The rate-limiting step in the biosynthesis of polyamines is catalyzed by ornithine decarboxylase (ODC). The activity of ODC and the level of intracellular polyamines significantly increase in many cancers, indicating the critical role of polyamines in tumorigenesis. Depletion of polyamines sensitizes cells to DNA damage agents that lead to DNA double-strand breaks (DSBs), suggesting that endogenous polyamines may participate in DNA repair process. However, the mechanistic role of polyamines in DSB repair remains largely unknown. Here, we wish to ascertain the role of polyamines in DSBs repair pathway and to delineate the underlying mechanism by combining biochemical analyses, cell-based and animal approaches. Our cell-based experiments demonstrated that polyamines indeed participate in DNA double-strand break repair. Specifically, the level of intracellular polyamines regulates homologous recombination (HR) repair pathway rather than non-homologous end joining (NHEJ). Furthermore, our in vitro reconstitution system and functional analyses demonstrated that polyamines significantly enhance RAD51-mediated DNA strand exchange reaction. Importantly, we reveal that the stimulatory effect of polyamines by RAD51 stems from the enhancement of duplex DNA captures in the DNA exchange reaction. Finally, the physiological role of polyamines in DSBs repair was examined by using mouse hair follicle as a model system. The animal model clearly highlights the significant contribution of polyamines to the DNA repair in vivo. Our findings thus furnish valuable insight into the mechanistic basis of polyamines in DNA repair.

Citation Format: Chih-Ying Lee, Guan-Chin Su, Min-Yu Ko, Wen-Yen Huang, Geen-Dong Chang, Sung-Jan Lin, Peter Chi. The mechanistic role of polyamines in DNA double-strand break repair [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2474. doi:10.1158/1538-7445.AM2017-2474
Abstract 248: Eicosapentaenoic acid attenuates obesity-related hepatocellular carcinogenesis
Authors: Inoue-Yamauchi Akane , Itagaki Hiroko , Oda Hideaki
Published: July 2017

The population of obesity caused by excess energy intake and insufficient physical activity is increasing worldwide. Excess accumulation of body fat is a risk of health, indeed obesity is associated with the pathogenesis of various disease including type II diabetes, cardiovascular disease and cancer. Among various kinds of cancer, the risk of hepatocellular carcinoma (HCC) is strongly influenced by obesity. Studies using diet-induced obesity mouse models show that obesity enhances tumor development inducing chronic inflammation in liver. In fact, obesity failed to promote HCC formation in the absence of inflammatory cytokines IL-6 and TNF-α. Eicosapentaenoic acid (EPA), an omega-3 polysaturated fatty acid, has been shown its anti-inflammatory properties and could be therapeutically useful to ameliorate inflammatory diseases. However, little is known about the effects of EPA on liver cancer which is linked to obesity-related inflammation. Therefore, we tested the effects of EPA on obesity-induced inflammatory response and following tumor development. We used the hepatic procarcinogen dietylnitrosamine (DEN) to induce HCC formation in mice. Since high-fat diet (HFD) can induce obesity and significantly enhance HCC formation in DEN-injected mice, this model is useful to assess tumor promotion on obesity. Using this model, we examined therapeutic potential of EPA in obesity-related cancer. As a result, we found that tumor growth in mice fed HFD supplemented with EPA was reduced compared to HFD-fed mice, indicating that EPA attenuates obesity-related hepatocarcinogenesis. Interestingly, EPA had no obvious effects on obesity-induced inflammation, instead, inhibited tumor growth by suppression of the protumorigenic transcription factor Stat3 signaling. These data suggest translational implications for the treatment of obesity-related HCC.

Citation Format: Akane Inoue-Yamauchi, Hiroko Itagaki, Hideaki Oda. Eicosapentaenoic acid attenuates obesity-related hepatocellular carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 248. doi:10.1158/1538-7445.AM2017-248
Abstract 2481: RAD51 and AICDA define a new synthetic lethal interaction that is targetable in multiple tumor types
Authors: Mills Kevin D. , Roche Marly I. , Cyr Amber , Maclay Tyler , Hasham Muneer G. , Lamont Kristin , Branca Jane , Cavallo Francesca , Cavallo Francesca , Jasin Maria , Stern Alvin , Kwon Youngho , Zhao Weixing , Sung Patrick
Published: July 2017

Antigen stimulated B-cells transiently express Activation Induced Cytidine Deaminase (AID) which initiates point mutations and DNA double strand breaks (DSB) in immunoglobulin genes to promote B-cell maturation. However, AID is capable of broadly damaging the B-cell genome. We have shown that AID-induced DSBs require the homologous recombination factor RAD51 for their repair. Using genetic approaches, we discovered that reduced HR function is cytotoxic to AID-expressing B-cells. We subsequently demonstrated the feasibility of small molecule inhibition of RAD51 to sensitize AID-overexpressing tumor cells. Here we build on those observations, finding that AID-RAD51 synthetic lethality occurs via mitotic catastrophe, involving the mTOR pathway. We have now developed potent and selective RAD51 modulatory small molecules that preferentially kill AID-expressing tumor cells. Using mouse models of lymphoma and leukemia we provide in vivo efficacy data demonstrating the potential therapeutic feasibility of RAD51 modulation. These studies provide evidence for a novel “synthetic lethal” approach for treating AID-expressing malignancies, via the induction of mitotic catastrophe.

Citation Format: Kevin D. Mills, Marly I. Roche, Amber Cyr, Tyler Maclay, Muneer G. Hasham, Kristin Lamont, Jane Branca, Francesca Cavallo, Francesca Cavallo, Maria Jasin, Alvin Stern, Youngho Kwon, Weixing Zhao, Patrick Sung. RAD51 and AICDA define a new synthetic lethal interaction that is targetable in multiple tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2481. doi:10.1158/1538-7445.AM2017-2481
Abstract 2482: Inhibition of RAD51 with a cell penetrating antibody, 3E10
Authors: Glazer Peter M. , Turchick Audrey
Published: July 2017

Many human malignancies arise in the setting of defective DNA repair pathways, leading to genetic instability, carcinogenesis and tumor progression. However, DNA repair deficiency can provide for a therapeutic window that can be exploited with targeted agents. One such anti-cancer agent is 3E10, a unique cell penetrating, anti-DNA autoantibody. 3E10 by itself is considered non-toxic to normal cells but has been shown to have deleterious effects on cells with DNA repair deficiencies. Specifically, 3E10 has been shown to reduce the efficiency of homologous recombination (HR). This has been attributed to its ability to preferentially binding to ssDNA tails, thereby inhibiting Rad51 mediated strand exchange. Prior work has shown that treatment with 3E10 alone can selectively kill cells with genetic mutations that lead to abnormal DNA repair. For example, 3E10 has been shown to be synthetically lethal in BRCA2 deficient human cancer cells. Additionally, 3E10 sensitizes cells to radiation and other DNA damaging therapies. The goal of this project is to characterize the specific mechanism by which 3E10 inhibits DNA repair pathways. Previously, the mechanism by which 3E10 inhibits HR was attributed to 3E10’s DNA binding ability. Through the biochemical evaluation of 3E10 variants, new evidence now suggests that 3E10 inhibits HR independently of 3E10’s ability to bind DNA. We have found that this HR inhibition is a result of a physical interaction between 3E10 and Rad51. Biochemical analysis revealed that 3E10 binds to the N-terminal domain of Rad51, the domain that plays a role in Rad51 homo-oligomerization and filament formation. This 3E10-Rad51 interaction impairs Rad51’s ability to localize to the nucleus and form repair foci. Taken together, this data suggests that 3E10 inhibits HR by physically interacting with Rad51. Overall, 3E10 holds promise as a novel therapeutic agent for certain subsets of cancer.

Citation Format: Peter M. Glazer, Audrey Turchick. Inhibition of RAD51 with a cell penetrating antibody, 3E10 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2482. doi:10.1158/1538-7445.AM2017-2482
Abstract 2493: Identification of the mutant p53-PARP-MCM chromatin axis as a triple negative breast cancer replication stress target
Authors: Qiu Wei-Gang , Polotskaia Alla , Xiao Gu , Di Lia , Zhao Yuhan , Hu Wenwei , Philip John , Hendrickson Ronald , Bargonetti Jill
Published: July 2017

Approximately 15% of all breast cancer is triple-negative and of these about 80% are found to have mutations in the gene for the tumor suppressor p53 (TP53). Many TP53 mutations encode gain-of-function oncogenic mutant p53 (GOF mtp53) protein. We used inducible knockdown of endogenous GOF mtp53 in MDA-MB-468 cells in conjunction with stable isotope labeling with amino acids in cell culture (SILAC) and subcellular fractionation. We sequenced over 70,000 total peptides for chromatin and cytoplasmic reciprocal data sets and were able to identify 3,010 unique cytoplasmic fraction proteins and 3,403 unique chromatin fraction proteins. We found that the heterohexomeric minichromosome maintenance (MCM) complex (MCM 2-7) along with PARP are high mtp53-chromatin associated pathways. When we depleted R273H mtp53 we found a large reduction of the amount of MCM complex and PARP proteins on the chromatin. Furthermore a direct mtp53-MCM2 interaction was detected. Overexpressed mtp53, but not wild type p53, showed a protein-protein interaction with MCM2 and MCM4. We treated cells with the PARP inhibitor talazoparib and the alkylating agent temozolomide and detected synergistic activation of apoptosis only in the presence of functional MCM2-7 and mtp53. The mtp53-PARP-MCM axis has potential use as a therapeutic and diagnostic target.

Citation Format: Wei-Gang Qiu, Alla Polotskaia, Gu Xiao, Lia Di, Yuhan Zhao, Wenwei Hu, John Philip, Ronald Hendrickson, Jill Bargonetti. Identification of the mutant p53-PARP-MCM chromatin axis as a triple negative breast cancer replication stress target [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2493. doi:10.1158/1538-7445.AM2017-2493
Abstract 2513: Multi-omics-based approach to colorectal cancer metabolism
Authors: Satoh Kiyotoshi , Soga Tomoyoshi
Published: July 2017

Cancer cells exhibit many metabolic alterations to acquire energy and cellular components required for their proliferation and thus, cancer specific metabolic pathways are attractive targets for cancer therapy. However, the regulation mechanisms underlying metabolic reprogramming are poorly understood. Here, we performed multi-omics-based analyses of paired normal and tumor tissues from patients with colorectal cancer (CRC) to understand the regulation mechanisms of metabolism in colorectal cancer. First, we carried out capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS)-based metabolome profiling of tumor and normal tissue obtained from 275 patients with CRC. S-adenosylmethionine (SAM), a principal methyl group donor produced by one-carbon metabolism, was the most increased metabolite in tumor tissue. Glucose was the second most decreased metabolite in tumor tissue, whereas lactate was accumulated, indicating activation of glycolysis, commonly known as the Warburg effect. Every amino acid except glutamine, the starting metabolite in glutaminolysis, was significantly accumulated in tumor tissue. Interestingly, most of the changes in metabolite levels were occurred in the adenoma stage. In addition, next-generation and Sanger sequencing analyses of genomic DNA obtained from tumor tissue revealed that metabolic alterations occurred independently of mutations in oncogenes and tumor suppressor genes, such as KRAS, APC, and TP53. Furthermore, DNA microarray analysis of paired normal and tumor tissues from CRC patients demonstrated that expression profiles of many metabolic genes were also altered at the adenoma stage. Most of genes regulating purine/pyrimidine synthesis, one-carbon metabolism and fatty acid synthesis were highly expressed, whereas those in fatty acid oxidation were down-regulated in tumor tissue. We will discuss the raised questions, which molecules contribute to the regulation of metabolic reprogramming of colorectal cancer metabolism.

Citation Format: Kiyotoshi Satoh, Tomoyoshi Soga. Multi-omics-based approach to colorectal cancer metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2513. doi:10.1158/1538-7445.AM2017-2513
Abstract 2519: Analysis of gene expression patterns and metabolomics correlated to obesity, diabetes, and outcomes in patients with epithelial ovarian cancer
Authors: Montgomery Allison M. , Londono Angelina I. , Craig Eric R. , Tawfik Cindy , Smith Haller J. , Leath Charles A. , Katre Ashwini A. , Cooper Sara J. , Arend Rebecca C.
Published: July 2017

Objective: Diabetes and obesity have been associated with a poor prognosis in ovarian cancer (OVCA); the exact mechanism has yet to be determined. Data suggests that obesity diminishes normal immunological response and better prognoses in non-obese patients may be attributable to an intact immune response. The objective of this study was to analyze the correlation between gene expression pattern/metabolomics and obesity/diabetes in OVCA patients..

Methods: Following IRB approval, UAB patients with suspected OVCA undergoing surgery were consented. Tissue was collected during cytoreduction and 35 samples were analyzed using RNAseq technology and mass spectrometry-based metabolomics. DESeq2 was used for RNAseq analysis to identify gene expression differences between diabetics and non-diabetics stratified by BMI: obese (BMI ≥30) and non-obese (BMI <30). Gene set enrichment analysis was conducted to determine whether there was an over-representation of immune pathways among altered genes. Profiles were normalized in the analysis of the metabolite profiles using ChromaTOF.

Results: 76 genes (p-value <0.05) were differentially expressed in the tumor samples from patients with BMI ≥30 to those <30. These genes were highly enriched for immune-related genes, including 34 immunoglobulin genes, and complement activation. The list of identified genes also included 3 HLA genes (HLA-G(down), HLA-H(up) and HLA-DMA(down). Furthermore, when analyzing tumor from diabetics (n=7), there were 18 genes differentially expressed compared to controls. These genes are not statistically enriched for any functional class. Additionally, genes associated with response to platinum-based therapy, differentiating patients with BMI≥30 v. <30 were analyzed. No genes met genome-wide significance; however, there were 14 genes with a genome-wide p-value<0.1. When diabetes status as a covariate was controlled for, this number was reduced to 9.

Conclusion: By evaluating the transcriptomic profiles generated through RNAseq analysis, a significant number of differences in RNA expression were identified in comparing obese to non-obese OVCA patients. Due to the small sample size, no genes were identied as being associated with the presence or absence of diabetes.

Citation Format: Allison M. Montgomery, Angelina I. Londono, Eric R. Craig, Cindy Tawfik, Haller J. Smith, Charles A. Leath, Ashwini A. Katre, Sara J. Cooper, Rebecca C. Arend. Analysis of gene expression patterns and metabolomics correlated to obesity, diabetes, and outcomes in patients with epithelial ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2519. doi:10.1158/1538-7445.AM2017-2519
Abstract 2535: MicroRNA-518c-5p promotes the metastasis of oral cancer
Authors: Kinouchi Makoto , Uchida Daisuke , Kuribayashi Nobuyuki , Komiyama Yuske , Tsuchida Shuji , Kawamata Hitoshi
Published: July 2017

We have demonstrated that CXCR4 system is involved in the metastatic process of oral cancer. Recently, we identified the miR-518c-5p as a downstream target of the CXCR4 system. In this study, we examined the function of miR-518c-5p on the metastasis of oral cancer. We transfected miR-518c expression vector into oral cancer cells, B88 and CAL27, and isolated stable transfectants, B88-518c and CAL27-518c, respectively. The growth and migration of both cells were significantly enhanced in compared with those of mock cells. LNA-based miR-518c-5p inhibitor significantly impaired the enhanced cell growth and migration of these cells, indicating that these phenomena were dependent on the expression of miR-518c-5p, not on that of miR-518c-3p. Next, we examined the function of miR-518c-5p in vivo. miR-518c or mock transfectants were inoculated into the masseter muscle or the blood vessels of nude mice. Tumor volume, lymph nodes metastasis, and lung metastasis were significantly increased in the mice inoculated with miR-518c transfectants. Furthermore, we examined the mRNA expression induced by miR-518c-5p using B88 cells and B88-518c cells by cDNA microarray analysis. Consequently, some of the genes involved in the cell growth and metastasis were upregulated in the B88-518c cells.

These results indicate that CXCR4 system regulates the metastases of oral cancer via induction of miR-518c-5p.

Citation Format: Makoto Kinouchi, Daisuke Uchida, Nobuyuki Kuribayashi, Yuske Komiyama, Shuji Tsuchida, Hitoshi Kawamata. MicroRNA-518c-5p promotes the metastasis of oral cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2535. doi:10.1158/1538-7445.AM2017-2535
Abstract 2543: The novel long non-coding RNA TALNEC2, regulates tumor cell growth and the stemness and radiation response of glioma stem cells
Authors: Jiang Wei , Brodie Shlomit , Cazacu Simona , Xiang Cunli , Poisson Laila , Kalkanis Steve , Ginsberg Doron , Brodie Chaya
Published: July 2017

Despite advances in novel therapeutic approaches for the treatment of glioblastoma (GBM), the median survival of 12-14 months has not changed significantly. Therefore, there is an imperative need to identify molecular mechanisms that play a role in patient survival. Here, we analyzed the expression and functions of a novel lncRNA, TALNEC2 that was identified using RNA seq of E2F1-regulated lncRNAs. TALNEC2 was localized to the cytosol and its expression was E2F1-regulated and cell-cycle dependent. TALNEC2 was highly expressed in GBM with poor prognosis, in GBM specimens derived from short-term survivors and in glioma cells and glioma stem cells (GSCs). Silencing of TALNEC2 inhibited cell proliferation and arrested the cells in the G1\S phase of the cell cycle in various cancer cell lines. In addition, silencing of TALNEC2 decreased the self-renewal and mesenchymal transformation of GSCs, increased sensitivity of these cells to radiation and prolonged survival of mice bearing GSC-derived xenografts. Using miRNA array analysis, we identified specific miRNAs that were altered in the silenced cells that were associated with cell-cycle progression, proliferation and mesenchymal transformation. Two of the downregulated miRNAs, miR-21 and miR-191, mediated some of TALNEC2 effects on the stemness and mesenchymal transformation of GSCs. In conclusion, we identified a novel E2F1-regulated lncRNA that is highly expressed in GBM and in tumors from patients of short-term survival. The expression of TALNEC2 is associated with the increased tumorigenic potential of GSCs and their resistance to radiation. We conclude that TALNEC2 is an attractive therapeutic target for the treatment of GBM.

Citation Format: Wei Jiang, Shlomit Brodie, Simona Cazacu, Cunli Xiang, Laila Poisson, Steve Kalkanis, Doron Ginsberg, Chaya Brodie. The novel long non-coding RNA TALNEC2, regulates tumor cell growth and the stemness and radiation response of glioma stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2543. doi:10.1158/1538-7445.AM2017-2543
Abstract 2544: The lncRNA Meg3 acts as an epigenetic determinant of oncogenic signaling in multiple endocrine neoplasia type 1
Authors: Iyer Sucharitha , Agarwal Sunita
Published: July 2017

Loss of tumor suppressors and gain of oncogenic properties is a hallmark of cancer. But the pathways leading to tumor formation are poorly understood. A good example is the multiple endocrine neoplasia type 1 (MEN1) syndrome, in which patients inherit germline mutations in the MEN1 gene, predisposing to tissue-specific loss of the encoded tumor suppressor protein menin. Consequently, tumors develop in multiple endocrine organs - the pituitary, the parathyroids, and the duodeno-pancreatic tissues, including pancreatic neuroendocrine tumors (PNETs). Insulinomas are the most common type of functioning PNETs that also occur in MEN1 patients. We investigated the molecular pathways associated with insulinomas. We previously showed that menin loss downregulated Maternally Expressed Gene 3 (MEG3), a long non-coding RNA (LncRNA), by eliciting promoter hypermethylation along with the loss of Histone H3 lysine 4 trimethylation (H3K4me3). Gene expression microarray analyses and RT-PCR, of mouse insulinoma MIN6 cells stably transfected with Meg3, showed a 5-fold decrease in the proto-oncogenic signaling receptor c-Met, suggesting a tumor suppressor function for Meg3. We also found MEG3 downregulation with concurrent upregulation of c-MET in PNETs. However, the molecular underpinnings of MEG3 governed c-MET repression remain elusive. To identify the mechanisms by which MEG3 inhibits oncogenic c-MET signaling to suppress tumorigenesis, we examined the effect of various Meg3 isoforms, explored Meg3 association with the epigenetic regulatory machinery, and RNA-DNA triplex formation. We provide direct evidence for the first time that ectopically expressed Meg3 isoforms could attenuate the highly abundant c-Met transcript in MIN6 insulinoma cells. Meg3 also interacted with components of the epigenetic machinery, such as the Polycomb Repressive Complex 2 (PRC2) protein conglomerate, to regulate c-Met RNA expression. Additionally, analyses of triplex forming oligos (TFOs) in MIN6 cells revealed that triple helix formation between Meg3 and dsDNA could potentially disrupt c-Met transcription. Combined, these data offer mechanistic insight into the dysregulation of c-MET repression in PNETs, and support the conclusion that MEG3 acts as an important determinant of oncogenic signaling in MEN1-associated endocrine tumor cells (insulinoma). These findings warrant further investigation into the tumorigenic pathways that may result from the loss of tumor suppressor MEG3 and gain of oncogenic c-MET signaling in other MEN1-associated endocrine tumors.

Citation Format: Sucharitha Iyer, Sunita Agarwal. The lncRNA Meg3 acts as an epigenetic determinant of oncogenic signaling in multiple endocrine neoplasia type 1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2544. doi:10.1158/1538-7445.AM2017-2544
Abstract 2548: Oncogenic function and molecular mechanism of H19 noncoding RNA in colorectal cancer
Authors: Ling Hui , Ohtsuka Masahisa , Ivan Cristina , Pichler Martin , Chen Meng , Slaby Ondrej , Goel Ajay , Radovich Milan , Calin George
Published: July 2017

The clinical significance of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC) remains largely unknown. We analyzed a large panel of cancer-associated lncRNAs in 483 TCGA CRC cases, and identified that H19 correlates most significantly with overall survival and disease-free survival, independent of stage and other clinical parameters. We validated the TCGA findings with two additional CRC cohorts. As one of the “oldest” lncRNAs, diverse activities of H19 including interaction with epigenetic regulators, regulation of microRNAs as competing endogenous RNA (ceRNA), and production of miR-675 as a primary transcript have been reported. However, an unbiased study to clarify the essential mechanisms of H19 is lacking. To decipher the functional involvement of H19 in CRC, we used an integrative approach combining unbiased microarray analysis, experimental validation, and bioinformatic analysis of clinical data. With such approach, we revealed not only previously reported mechanisms such as let-7 and MYC regulation by H19, but also several novel mechanisms that have not been appreciated before. We discovered a mechanism of H19 on regulating RB-E2F signaling and accordingly controlling cell cycle progression. We also identified for the first time that H19 regulates CDK8, an oncogenic driver in CRC pathogenesis, and consequently affects β-catenin activity (Firestein et al., Nature, 2008). We further identified an interaction of H19 with macroH2A, a histone variant reported to repress CDK8 transcription (Kapoor et al., Nature, 2010). Importantly, expression correlation analysis with clinical samples strongly supported the above-identified mechanisms. Combined analysis of H19 with its targets showed strong independent prediction power for CRC survival. These data indicate the clinical relevance of Rb-E2F and CDK8/β-catenin signaling in mediating H19’s oncogenic activity in CRC.

Citation Format: Hui Ling, Masahisa Ohtsuka, Cristina Ivan, Martin Pichler, Meng Chen, Ondrej Slaby, Ajay Goel, Milan Radovich, George Calin. Oncogenic function and molecular mechanism of H19 noncoding RNA in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2548. doi:10.1158/1538-7445.AM2017-2548