bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2599: Association of periodontal disease and breast health in women undergoing screening mammography
Authors: Park Hannah Lui , Acheampong Teofilia , Nguyen Kathleen , Nguyen Cindy , Ziogas Argyrios , Kelly Richard , Alvarez Andrea , Larsen Kathryn M. , Goodman Deborah , Anton-Culver Hoda
Published: July 2016

It is well established that chronic and persistent inflammation contributes to cancer development. Chronic inflammation is often associated with periodontal disease, or gum disease. Periodontal disease, which can be prevented or ameliorated by following proper oral hygiene, is known to be associated with various systemic disorders including coronary heart disease and some cancers, including head and neck cancer and pancreatic cancer. However, little is known about its potential association with breast cancer, with only one report in which periodontal disease was a positive predictor for breast cancer in a Swedish cohort. To examine if a potential link exists between periodontal disease and breast cancer in a separate cohort, mammography patients from the UC Irvine Athena Breast Health Network cohort were recruited to participate in a survey that included questions about their periodontal health. Diagnosis of invasive breast cancer, DCIS, and benign breast diseases was determined through data extraction from electronic medical records. There was no association between periodontal disease and DCIS or invasive breast cancer. However, there was a significant difference in the frequency of breast cysts among women with periodontal disease compared to women without periodontal disease (p<0.01). Women with periodontal disease were at least 4-fold more likely to have breast cysts, even after adjusting for potential confounders including age, race/ethnicity, and smoking history (p<0.05). To our knowledge, this is the first report on an association between periodontal disease and breast cysts. Our data suggest that further studies on potential links between periodontal disease and breast health are warranted.

Citation Format: Hannah Lui Park, Teofilia Acheampong, Kathleen Nguyen, Cindy Nguyen, Argyrios Ziogas, Richard Kelly, Andrea Alvarez, Kathryn M. Larsen, Deborah Goodman, Hoda Anton-Culver. Association of periodontal disease and breast health in women undergoing screening mammography. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2599.
Abstract 2624: Possibility of prostate cancer prevention based on cancer stem cell theory
Authors: Shiozawa Nobuya , Sugahara Ryosuke , Sato Ayami , Ota Masako , Yano Tomohiro
Published: July 2016

Cancer stem cells are considered to be one of the causes of cancer. In recent years, stemness (stem like) of gene expression patterns in the development process of cancer has been observed. Stemness and pathology of cancer are closely related. Elucidation of the stemness regulation of cancer is an important key to the development of new cancer prevention methods. However, as far as we know, there exist no cancer prevention studies focusing on cancer stem cells. In this study, we have investigated the possibility of prostate cancer prevention with a focus on cancer stem cells. We utilized prostate cancer cell lines PC3, DU145 (androgen-independent) and LNCaP (androgen-dependent) cells. Then, using spheroid formed cells, mRNA expression levels of cancer stem cells markers were estimated by RT-real time-PCR. Cancer cells have several malignant phenotypes under hypoxia, and we investigated for the cancer stem cells induced malignant alteration under hypoxia. In addition, under hypoxia, we investigated cell viability effect under tocotrienol-rich fraction (TRF) from annatto. TRF almost consists of delta- tocotrienol (δ-T3) that has the strongest anti-cancer activity. We observed spheroid formation capacity and compared the spheroid sizes and mRNA levels of DU145, PC3 and LNCaP cells. Size of DU145 spheroid is smaller in comparison to spheroids of PC3 and LNCaP. mRNA expression levels of cancer stem cells marker were elevated in PC3 and LNCaP cells. This means that PC3 and LNCaP cells have higher concentration of cancer stem cells. Furthermore, stemness decreases with increase of passage number, the number of cultures. We confirmed the presence of stemness in the formation capacity of spheroid until passage 4. Under hypoxia, cell viability of cancer stem cells was elevated compared to normal cultured prostate cancer cells. In addition, under hypoxia and TRF treatment, cell viability of cancer stem cells decreased with increase in TRF concentration compared to control (0 μg/ml). Our results suggest that TRF suppress cell viability of prostate cancer stem cells under hypoxic states and is effective in prostate cancer prevention.

Citation Format: Nobuya Shiozawa, Ryosuke Sugahara, Ayami Sato, Masako Ota, Tomohiro Yano. Possibility of prostate cancer prevention based on cancer stem cell theory. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2624.
Abstract 2655: Oncogenic chromatin factors drive cell type-specific transcription within megadomains in NUT midline carcinoma
Authors: Kuroda Mitzi I. , Alekseyenko Artyom A. , Walsh Erica M. , Wang Xin , Grayson Adlai , Hsi Peter T. , Kharchenko Peter V. , French Christopher A.
Published: July 2016

NUT midline carcinoma (NMC), a subtype of squamous cell cancer, is one of the most aggressive human solid malignancies known. NMC is driven by the creation of a translocation oncoprotein, BRD4-NUT, which blocks differentiation and drives growth of NMC cells. BRD4-NUT forms distinctive nuclear foci in patient tumors, which we find correlate with ∼100 unprecedented, hyperacetylated expanses of chromatin that reach up to 2 Mb in size. These ‘megadomains’ appear to be the result of aberrant, feed-forward loops of acetylation and binding of acetylated histones. Megadomains drive transcription of underlying DNA in NMC patient cells and in naïve cells induced to express BRD4-NUT. Here we characterize the constituents of BRD4-NUT chromatin complexes using a crosslinking approach, BioTAP-XL. We find many transcriptional activating proteins known to associate with BRD4, along with novel interactors including p300/CBP and a previously uncharacterized BRD4-NUT Megadomain Associated Protein (BMAP1). BMAP1 is expressed in primary NMC tissue and a subset of more common head and neck squamous cell carcinomas (HNSQC). Concurrently, we discovered a patient-derived NMC harboring a novel BMAP1-NUT fusion. BMAP-NUT blocks differentiation, and like BRD4-NUT recruits p300 to form hyperacetylated megadomains, including at the MYC locus. Thus, our proteomic and genetic approaches have converged on a novel mechanism that involves reprogramming very large regulatory regions to drive oncogenic transcription.

Citation Format: Mitzi I. Kuroda, Artyom A. Alekseyenko, Erica M. Walsh, Xin Wang, Adlai Grayson, Peter T. Hsi, Peter V. Kharchenko, Christopher A. French. Oncogenic chromatin factors drive cell type-specific transcription within megadomains in NUT midline carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2655.
Abstract 2659: A novel isoform of TET1 that lacks a CXXC domain is overexpressed in cancer
Authors: Good Charly R. , Madzo Jozef , Maegawa Shinji , Engel Nora , Jelinek Jaroslav , Issa Jean-Pierre
Published: July 2016

TET1 is a DNA demethylase that regulates DNA methylation, hydroxymethylation and gene expression patterns. It has a catalytic domain that oxidizes methylated cytosine into 5-hydroxymethylcytosine and can then be further oxidized or converted to un-methylated cytosine. TET1 has a CXXC domain that allows it to recognize and bind to long stretches of CpG dinucleotides, known as CpG islands (CGIs). Our previous work found TET1 to protect CGIs from aberrant methylation and that the CXXC domain limits its ability to regulate genes outside of CGIs. However, many of the methylation changes in cancer are outside CGIs. To determine if TET1 could possibly play a role in this hypomethylation, we searched for alternatively spliced forms of the protein. We identified a novel isoform of TET1 (TET1ALT) that lacks the CXXC domain but retains the demethylase domain. TET1ALT has a unique transcription start site from a strong alternate promoter upstream of exon 3, yielding a protein with a unique translation start site. We confirmed promoter activity using Luciferase constructs, and confirmed TET1ALT translation and function through overexpression experiments. Gene expression analyses by qPCR found that TET1ALT is silenced in mESCs but becomes activated in select embryonic and adult tissues while full length TET1 is favored in mESCs, but is repressed in adult tissues. Thus, there is an isoform switch during differentiation and TET1ALT is the major isoform expressed in adult cells. TET1ALT is over expressed in several cancer cell lines, including breast cancer. In conclusion, we have identified a novel isoform of TET1 that has the potential to regulate DNA methylation outside of CGIs and is the predominant isoform expressed in adult cells. We are investigating the hypothesis that TET1ALT may contribute to the methylation changes observed in cancer outside of CGIs, such as in gene bodies and in enhancers.

Citation Format: Charly R. Good, Jozef Madzo, Shinji Maegawa, Nora Engel, Jaroslav Jelinek, Jean-Pierre Issa. A novel isoform of TET1 that lacks a CXXC domain is overexpressed in cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2659.
Abstract 2670: Non-metabolic function of asparagine in regulating global protein translation
Authors: Zhang Ji , Pavlova Natalya , White Richard , Thompson Craig
Published: July 2016

Cancer cells rely on extracellular glutamine for growth and survival. Previously, we showed that asparagine, a nonessential amino acid that can be synthesized de novo from glutamine, is both necessary and sufficient for glutamine-dependent cell survival. In addition, asparagine synthetase (ASNS) expression positively correlates with the progression of the disease in human glioma patients, suggesting a critical role of asparagine during tumor progression. Interestingly, mammalian cells cannot catabolize asparagine for use as either a nitrogen source or a bioenergetic substrate, potentially due to the loss of asparaginase activity during evolution. Ectopic expression of yeast or zebrafish asparaginase restores the capacity of mammalian cells to utilize asparagine as both bioenergetic and biosynthetic substrates to support cell growth. Furthermore, asparagine restores translation of fast-turn-over proteins under glutamine starvation. Together, the data suggests that asparagine has been evolved to be a metabolic reserve to regulate cellular adaptation to nonessential amino acid limitation in mammalian cells and is therefore a potential target for cancer therapy.

Citation Format: Ji Zhang, Natalya Pavlova, Richard White, Craig Thompson. Non-metabolic function of asparagine in regulating global protein translation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2670.
Abstract 2673: Inhibition of fatty-acid oxidation as a therapy for MYC-overexpressing triple-negative breast cancer
Authors: Camarda Roman , Zhou Alicia Y. , Kohnz Rebecca A. , Balakrishnan Sanjeev , Mahieu Celine , Anderton Brittany , Eyob Henok , Kajimura Shingo , Tward Aaron , Krings Gregor , Nomura Daniel K. , Goga Andrei
Published: July 2016

Expression of the oncogenic transcription factor MYC is disproportionately elevated in triple-negative breast cancer (TNBC) compared to estrogen, progesterone and/or human epidermal growth factor 2 receptor-positive (RP) breast tumors. We and others have shown that MYC alters metabolism during tumorigenesis. However, the role of MYC in TNBC metabolism remains largely unexplored. We hypothesized that pharmacologic inhibition of MYC-driven metabolic pathways may serve as a therapeutic strategy for this clinically challenging subtype of breast cancer. Using a targeted metabolomics approach, we identified fatty-acid oxidation (FAO) intermediates as dramatically upregulated in a MYC-driven model of TNBC. A lipid metabolism gene signature was identified in patients with TNBC in the TCGA and multiple other clinical datasets, implicating FAO as a dysregulated pathway critical for TNBC metabolism. We find that MYC-overexpressing TNBC, including a transgenic model and patient-derived xenograft (PDX), display increased bioenergetic reliance upon FAO. Pharmacologic inhibition of FAO catastrophically decreases energy metabolism of MYC-overexpressing breast cancer, blocks growth of a MYC-driven transgenic TNBC model and MYC-overexpressing PDX. Our results demonstrate that inhibition of FAO is a novel therapeutic strategy against TNBCs that overexpress MYC.

Citation Format: Roman Camarda, Alicia Y. Zhou, Rebecca A. Kohnz, Sanjeev Balakrishnan, Celine Mahieu, Brittany Anderton, Henok Eyob, Shingo Kajimura, Aaron Tward, Gregor Krings, Daniel K. Nomura, Andrei Goga. Inhibition of fatty-acid oxidation as a therapy for MYC-overexpressing triple-negative breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2673.
Abstract 2683: The landscape of chromosomal aberrations in mouse models of breast cancer reveals driver-specific routes to tumor development
Authors: Ben-David Uri , Ha Gavin , Khadka Prasidda , Jin Xin , Franke Lude , Golub Todd R.
Published: July 2016

Aneuploidy and large copy number alterations (CNAs) are a hallmark of human cancer. Although genetically engineered mouse models (GEMMs) are commonly used to model human cancer, their chromosomal landscape remains largely unexplored because large-scale CNA data have not been generated. Here we used gene expression profiles to infer CNAs in 3,108 samples from 45 mouse models, providing the first comprehensive catalog of chromosomal aberrations in cancer GEMMs. Mining this expansive resource, we found that most chromosomal aberrations accumulated late during breast tumorigenesis, and we observed marked differences in CNA prevalence between mouse mammary tumors initiated with distinct drivers. Some of these aberrations were recurrent and unique to specific GEMMs, suggesting distinct driver-dependent routes to tumor development. Synteny-based comparison of mouse and human tumors narrowed critical regions in CNAs, thereby identifying candidate driver genes that were not obvious from the analysis of either dataset alone. Specifically, we experimentally validated that loss of Stratifin (SFN) promotes HER2-induced tumorigenesis in human cells. These results demonstrate the power of GEMM CNA analysis in the understanding of human cancer pathogenesis.

Citation Format: Uri Ben-David, Gavin Ha, Prasidda Khadka, Xin Jin, Lude Franke, Todd R. Golub. The landscape of chromosomal aberrations in mouse models of breast cancer reveals driver-specific routes to tumor development. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2683.
Abstract 2704: Radiotherapy and immunotherapy in cancer: A mathematical model
Authors: Serre Raphael , Muracciole Xavier , Ciccolini Joseph , Benzekry Sebastien , Barbolosi Dominique
Published: July 2016

The rise of immunotherapy is a major breakthrough in oncology. Recently, the combination of radiotherapy with the blockade of immune checkpoint inhibitors such as the PD1-PDL1 axis or the CTLA4 pathway has shown a synergistic potential: in addition to the direct cell kill induced by irradiation, radiotherapy unleashes neoantigens that can further induce an anti-tumoral immune response. However, this immune response can be inhibited by the immunosuppressive nature of the tumor micro-environment (TME). Hence, radiotherapy combined with immune check-point inhibitors is a promising solution and is the subject of preclinical and clinical research. However, defining the most efficient scheduling between radiotherapy and immunotherapy is a crucial issue that cannot be properly addressed solely by empirical trial-and-error practices. Consequently, developing mathematical models that can describe the synergy between immune checkpoint inhibitors and radiotherapy is critical. Hence, we have built a pharmocodynamic model of the combination of radiotherapy with inhibitors of the PD1-PDL1 axis and/or the CTLA4 pathway. We describe a mathematical representation of how a growing tumor first elicits and then inhibits an anti-tumoral immune response. This anti-tumoral immune response is described by a primary and a secondary response. The primary immune response appears first and is down-regulated by the PD1-PDL1 axis, while the secondary immune response happens next and is down-regulated by the CTLA4 pathway. We describe the effects of irradiation by a slightly modified version of the Linear-Quadratic model. In particular, we explain the biphasic relationship between the size of a tumor and its immunogenicity, as measured by the abscopal immune response. The ability of the model to forecast pharmacodynamic endpoints was retrospectively validated by reproducing results from experimental studies investigating radiotherapy and immune checkpoint inhibitors. This model clarifies the issue of synchronisation of immunotherapy with radiotherapy and it also explains why the CTLA4 blockade often occurs with a delay. The model also explains why a sustained response to immunotherapy may or may not happen after treatment discontinuation. We believe that this mathematical model could be further used as a simulation tool to help decision-makers determine the optimal scheduling between radiotherapy and immunotherapy and could be a building block for the in-silico design of optimized multimodal strategies.

Citation Format: Raphael Serre, Xavier Muracciole, Joseph Ciccolini, Sebastien Benzekry, Dominique Barbolosi. Radiotherapy and immunotherapy in cancer: A mathematical model. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2704.
Abstract 2714: Inhibition of human telomerase by new purine analogs
Authors: Hernandez-Sanchez Wilnelly M. , Baus Diane , Berdis Anthony J. , Taylor Derek J.
Published: July 2016

Telomeres are the end caps of linear chromosomes that help to ensure genomic stability. Because of the inability of DNA polymerases to synthesize the extreme ends of the lagging strand, telomeres get slightly shorter each time a cell divides. When telomeres get extremely short, a state of senescence is triggered which halts cell division. Some cells that require an extended lifespan (e.g. embryonic cells, germ lines and stem cells) use an enzyme called telomerase to maintain telomeres at a length that is sufficient to escape senescence. Whereas telomerase is undetectable, in adult somatic tissue, it is upregulated in 85-90% of all metastatic tumors; enabling cancer cells to divide indefinitely. Due to this unique property of cancer cells, targeting telomerase is a viable chemotherapeutic approach. Nucleotide analogs have been shown to inhibit telomerase activity (e.g. azidothymidine or AZT), albeit modestly, to promote telomere shortening in cancer cell lines. Also, most of these nucleotide analogs are limited by requirement of high dosage (e.g. The IC50 of AZT varies from 0.25 to 1.35 mM). Therefore, while promising, there is a need to develop other nucleotide analogs that are more potent in inhibiting telomerase activity. We have screened a series of new purines analogs using a direct in vitro telomerase assay. These nucleotide analogs were developed to have different chemical modifications around the indole group of the nucleobase. We have identified two purine analogs (5-MeCITP and 6-NITP) that inhibit telomerase activity in vitro. 5-MeCITP was measured to have an inhibition constant (ki) of ∼45μM, which is significantly efficient. Future efforts will include evaluation of the lead nucleoside analogs in telomerase positive cancer cell lines to determine their effect on telomere length and cell survival.

Citation Format: Wilnelly M. Hernandez-Sanchez, Diane Baus, Anthony J. Berdis, Derek J. Taylor. Inhibition of human telomerase by new purine analogs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2714.
Abstract 2715: Cell cycle regulated mitophagy: a key step at the G1/S metabolic checkpoint
Authors: Annibali Daniela
Published: July 2016

How tumor cells coordinate their high demand for biosynthetic processes with nutrient availability, proliferation rate and oxidative stress tolerance is still not completely understood. We recently showed that highly proliferating cells, whether normal or tumorigenic, display different metabolic requirements throughout the cell cycle, in term of glucose and glutamine utilization. The role of autophagy in cancer cells is still debated, but recent evidence pointed to its involvement in the regulation of cellular bioenergetics and nutrients utilization. To investigate autophagy regulation during cancer cells proliferation and to characterize in detail the metabolic behaviour associated with tumor cell proliferation in the different phases of the cell cycle, we used synchronized HeLaS3, a human epithelial carcinoma cell line. Treatment of the cells with a double thymidine block (DTB) results in an arrest at the G1/S boundary and the possibility to study their progression through a complete division cycle. Here we show that in the highly proliferating HeLaS3 cancer cells basal autophagy is a cell cycle regulated phenomenon, responsible for mitochondria quality control and that it plays an essential role at the G1/S checkpoint. Both general autophagy genetic inhibition and mitophagy pharmacological inhibition with Mdivi-1 during cell cycle progression lead the cells to enter faster in S phase. However, probably due to the high levels of oxidative stress dictated by their proliferation rate, autophagy-incompetent cells start to accumulate insulted and less functional mitochondria. Autophagy is likely to be involved in the induction of resistance mechanisms to treatments in different types cancers. Because of this, there is an increased interest in the possibility to use inhibitors of the autophagic pathways as adjuvants for current anti-tumor therapies. Further investigations of the mechanisms here described will be of importance to elucidate whether drugs which inhibit autophagy may be a viable and effective approach in combination with chemotherapy for the treatment of highly proliferating cancers.

Citation Format: Daniela Annibali. Cell cycle regulated mitophagy: a key step at the G1/S metabolic checkpoint. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2715.
Abstract 2719: ADA3, a cell cycle regulator, regulates chromosome segregation
Authors: Srivastava Shashank , Mohibi Shakur , Wang-France June , Mirza Sameer , Zhao Xiangshan , Band Hamid , Bnad Vimla
Published: July 2016

The RNA polymerase II mediated transcription requires the higher degree structure of chromatin to be relieved so that general transcription machinery can access the DNA. The acetylation of DNA bound histones at specific loci is the major epigenetic modification by which opening of chromatin is achieved. HATs (Histone Acetyl Transferase) are the enzymes that catalyze the acetylation of histones and require association with mediator proteins for their function. One such mediator protein is ADA3 (Alteration/Deficiency in Activation 3), which was initially discovered as a component of multi-protein complex that contains either GCN5 (General Control Non-repressed 5) or PCAF (p300/CBP Associated Factor) as HAT and subsequent studies showed that ADA3 associates with another HAT, p300. As a HAT interacting protein, ADA3 enhances the acetylation of histones as well as non-histone proteins, such as p53.

We have recently shown that ADA3 is a cell cycle regulatory protein and is important for both G1 to S phase transition as well as mitosis. Conditional deletion of Ada3 from Ada3FL/FL MEFs (Mouse Embryonic Fibroblasts) causes cell cycle arrest and severe mitotic defects. To further explore the mechanism of ADA3 mediated mitosis, we performed ChIP-seq analyses and found that ADA3 bound to higher order repeat region of the centromere across most of the chromosomes. Further studies showed ADA3 interaction with centromere was mediated by a centromeric protein CENP-B. More importantly, siRNA mediated knockdown of ADA3 decreases the occupancy of CENP-B at centromere and causes chromosomal segregation defects during mitosis. These studies demonstrate a novel function of ADA3 in cell cycle regulation. Our current studies are focused on defining the exact mechanism of recruitment of ADA3 complex to CENP-B to regulate mitosis and its effect on genomic stability.

Citation Format: Shashank Srivastava, Shakur Mohibi, June Wang-France, Sameer Mirza, Xiangshan Zhao, Hamid Band, Vimla Bnad. ADA3, a cell cycle regulator, regulates chromosome segregation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2719.
Abstract 273: Inhibition of EGFR/STAT3/CEBPD axis reverses cisplatin cross-resistance with paclitaxel in urothelial carcinoma of urinary bladder
Authors: Wang. Ju-Ming
Published: July 2016

Cisplatin (CDDP) is frequently used in combination chemotherapy with paclitaxel (PTX) in the treatment of urothelial carcinomas of the urinary bladder (UCUB). The development of CDDP cross-resistance with PTX has been suggested and remains a challenge that hinders successful UCUB treatment. Consequently, elucidating the mechanisms underlying CDDP-induced anticancer drug resistance is imperative, and this knowledge will aid in the development of novel strategies. CEBPD expression was maintained in post-operative chemotherapy patients, and this expression was responsive to CDDP even in CDDP-resistant UCUB cells. Upon CDDP treatment, CEBPD activated ABCB1 and ABCC2. The EGFR/STAT3 pathway contributed to CDDP-induced CEBPD expression in UCUB cells. Treatment with gefitinib and S3I-201 significantly decreased CEBPD expression and enhanced sensitivity of CDDP-resistant NTUB1/P cells to CDDP and PTX. Our results demonstrate the risk of CEBPD activation in CDDP-resistant UCUB cells and suggest a potential therapeutic strategy for treating patients with UCUB and UCUB with CDDP-induced PTX resistance using CDDP in combination with either gefitinib or S3I-201.

Citation Format: Ju-Ming Wang. Inhibition of EGFR/STAT3/CEBPD axis reverses cisplatin cross-resistance with paclitaxel in urothelial carcinoma of urinary bladder. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 273.
Abstract 2733: Novel function of the RAI2 protein in genomic integrity of breast cancer cells
Authors: Werner Stefan , Borgmann Kerstin , Pantel Klaus , Wikman Harriet
Published: July 2016

We have recently identified the RAI2 protein as putative metastasis-suppressor related to dedifferentiation, early occurring bone metastasis formation, and survival of hormone dependent breast carcinomas. Nevertheless, low RAI2 expression is also predictive for poor patient outcome in hormone independent tumors and is furthermore associated with mutation of p53 in primary breast tumors. Thus, besides sustaining luminal differentiation, RAI2 might possess a general function as tumor suppressor that is, as indicated by association with p53 status, possibly related to maintenance of genomic stability.

In order to characterize its potential role in genomic integrity, we screened lysates from RAI2 depleted MCF-7 and KPL-1 breast cancer cell lines with phosphorylation-specific antibody arrays. Additionally, we analyzed changes in expression of cell cycle related genes and proteins by qPCR and Western Blot analysis. We also conducted cytogenetic assays to investigate whether RAI2 depletion affects chromosomal stability and mitotic progression. Finally, we evaluated a possible association of RAI2 expression with aneuploidy in published expression data sets from breast cancer patients.

As revealed by antibody array analysis, RAI2 depletion causes activation of p53 protein in MCF-7 and KPL-1 breast cancer cells, which was accompanied by a significant increase of senescent cells in the corresponding cell populations. Furthermore RAI2 depletion causes downregulation of several key factors of G2/M transition, like Aurora kinases A and B as well as Cyclins A2, B1 and B2. Concomitantly, we found in RAI2-depleted cell cultures reduction of mitotic index, increase of unattached chromosomes in metaphase and lagging chromosomes and during anaphase. This finding was further approved by an increase of numerical aberrations in RAI2 knockdown cells. Finally, we could show an association between low RAI2 expression and higher level of chromosomal instability in primary tumors from breast cancer patients.

In conclusion, we found that loss of RAI2 function is associated with decreased mitotic fidelity. Thus, besides sustaining differentiation in hormone dependent breast tumor, RAI2 also acts as general tumor suppressor that maintains genomic integrity.

Reference: Werner S et al., Cancer Discovery. 2015 May;5(5):506-19

Citation Format: Stefan Werner, Kerstin Borgmann, Klaus Pantel, Harriet Wikman. Novel function of the RAI2 protein in genomic integrity of breast cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2733.
Abstract 2737: Quantitative assessment of chromosome instability induced through chemical disruption of mitotic progression
Authors: Markossian Sarine , Arnaoutov Alexei , Saba Nakhle S. , Larionov Vladimir , Dasso Mary
Published: July 2016

Most solid tumors are aneuploid, carrying an abnormal number of chromosomes, and they missegregate whole chromosomes in a phenomenon termed chromosome instability (CIN). CIN is associated with poor prognosis in many cancer types, and targeting of CIN is an attractive strategy for anti-cancer therapeutics. The mechanisms causing CIN and its contributions to tumor initiation and growth are not well defined, partly because there is no straightforward, quantitative assays for CIN in human cells. To address this problem, we have developed the first Human Artificial Chromosome (HAC)-based quantitative live-cell assay for mitotic chromosome segregation in mammalian cells, with which we can easily score the rates of CIN within one cell division under different experimental conditions.

We have constructed a HAC encoding copies of enhanced green fluorescent protein (eGFP) fused to the destruction box (DB) of hSecurin, a substrate of the anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase, which becomes active during anaphase to catalyze the proteolysis of critical mitotic target proteins. This HAC also contains tet operator (tetO) arrays and sequences encoding the tetracycline repressor fused to monomeric cherry fluorescent protein (tetR-mCherry). We have produced human U2OS cells (U2OS-Phoenix) carrying this HAC, in which we monitor HAC segregation in two ways: First, APC/C degrades the DB-eGFP fusion expressed from the HAC at anaphase onset, and DB-eGFP re-accumulates in the daughter cells after G1 phase, when APC/C becomes inactive. Daughter cells that do not obtain a copy of the HAC will thus be GFP negative in the subsequent interphase. Second, because tetR-mCherry binds to the tetO arrays, the HAC itself could be followed by live imaging. Following the HAC by live cell imaging experiments, we show that U2OS-Phoenix cells have low inherent levels of CIN, but HAC missegregation is markedly increased by treatment with Reversine, an inhibitor of Mps1, and microtubule agents Nocodazole and Paclitaxel.

In summary, we have developed new assays to score CIN levels in human cells and have shown that CIN levels increase upon chemical disruption of mitotic progression, which makes our assays ideal for chemical screens.

Citation Format: Sarine Markossian, Alexei Arnaoutov, Nakhle S. Saba, Vladimir Larionov, Mary Dasso. Quantitative assessment of chromosome instability induced through chemical disruption of mitotic progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2737.
Abstract 2738: Establishing an in vitro cell culture model for studying the function of FAM190A deletions
Authors: Calhoun Eric S.
Published: July 2016

A growing number of studies have reported a variety of genetic alterations to FAM190A (CCSER1) in cancer. Interestingly, a large percentage of these are focused on deleting downstream exons producing in-frame arrangements for this protein. An analysis of coding sequences reveals that regions of FAM190A are highly conserved throughout the N-terminus, however, with no recognizable protein domains. Published immunofluorescence and shRNA knockdown studies have since suggested that FAM190A is localized to the midbody during cytokinesis and may function in maintaining genome stability. Unfortunately, attempts to overexpress FAM190A were not successful by these authors. The aim of our current study was to try to generate an in vitro model that would allow us to examine the effect of a C-terminal deletion on cellular division and FAM190A's ability to associate with the spindle and/or midbody structures. To accomplish this, full length FAM190A and a deletion mutant construct lacking exons 8-11 were separately cloned into mammalian expression vectors that include a N-terminal HaloTag Fusion marker and a modified CMV promoter. Current studies are focused on introducing these constructs into the pancreatic cancer cell line, PL-5, to generate FAM190A stably expressing cell lines.

Citation Format: Eric S. Calhoun. Establishing an in vitro cell culture model for studying the function of FAM190A deletions. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2738.
Abstract 2744: Synthetic lethal killing of RAD54B-deficient cancer cells by PARP1 silencing and inhibition
Authors: McAndrew Erin N. , Lepage Chloe C. , McManus Kirk J.
Published: July 2016

Colorectal Cancer (CRC) is the second leading cause of cancer-related deaths in North America. Currently, many chemotherapeutics are non-specific and preferentially kill cancer cells based on their high proliferation rate. However, due to the lack of tumor specificity, many treatments have unwanted side effects. Accordingly, identifying novel therapeutic strategies and drug targets that better target and combat cancer are needed. To address this need, synthetic lethal (SL) approaches are now being explored in many cancer contexts. Synthetic lethality refers to the lethal combination of two independently viable mutations and functions by exploiting the aberrant genetics contained within cancer cells. RAD54B is an excellent candidate to exploit using a SL paradigm as it normally functions in homologous recombination repair (HRR) and hypomorphic expression and/or function are implicated in tumorigenesis in a wide array of cancers. We predict that RAD54B and PARP1 are SL, as BRCA1 and BRCA2, which also encode functions within HRR, are SL with PARP1. To identify PARP1 as a novel SL interactor of RAD54B, we employed an established RNAi-based screening approach along with a RAD54B isogenic CRC model. Conceptually, following PARP1 silencing, a SL interaction will result in fewer cells within the RAD54B-deficient cells relative to RAD54B-proficient controls. Accordingly, we sought to determine whether PARP1 silencing or inhibition (Olaparib or BMN673) would induce selective killing within RAD54B-deficient HCT116 cells relative to controls. As predicted, PARP1 silencing with either individual or pooled siRNA duplexes and inhibition with both Olaparib and BMN673 was associated with statistically significant decreases in the number of RAD54B-deficient cells relative to controls. To confirm the SL interaction did not occur due to de novo mutations within the RAD54B-deficient cells, dual silencing of RAD54B and PARP1 was performed within the parental line and confirmed the above findings. Finally, real-time cellular analyses were conducted and revealed the decrease in cell numbers was due to cellular cytotoxicity rather than cell cycle arrest. Collectively, these data show that RAD54B and PARP1 are SL, and identify PARP1 is a candidate lead target in CRCs harboring RAD54B defects.

Citation Format: Erin N. McAndrew, Chloe C. Lepage, Kirk J. McManus. Synthetic lethal killing of RAD54B-deficient cancer cells by PARP1 silencing and inhibition. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2744.
Abstract 275: Combining low dose microtubule targeting agents with belinostat potentiates cytotoxic response in HDACi resistant diffuse large b-cell lymphoma
Authors: Havas Aaron P. , Bhakta Anvi , Rodrigues Kameron , Smith Catharine L.
Published: July 2016

Patients diagnosed with Diffuse Large B-cell lymphoma have an overall 60% five-year survival rate. New therapeutic approaches are needed to effectively treat aggressive forms of DLBCL that are refractory to the standard treatment or that relapse within two years of treatment. Histone deacetylase inhibitors (HDACi) are novel therapeutics that are well tolerated in humans and are being extensively evaluated in combination with other therapeutics against hematologic malignancies. Rational selection of companion therapeutics has been difficult due to the cell type-specific mechanisms of HDACi action. In order to address this, we have developed a pre-clinical model system of sensitivity and resistance to HDACi-induced cytotoxicity in DLBCL cell lines that share characteristics with aggressive DLBCL tumors. We previously reported that HDACi resistance is associated with reversible arrest in G1 that involves sustained up-regulation of cyclin-dependent kinase inhibitors. In the current study we demonstrate that HDACi-sensitive cell lines undergo mitotic arrest prior to anaphase in response to treatment with the approved HDACi, belinostat, consistent with activation of the spindle assembly checkpoint (SAC). In contrast, HDACi-resistant cell lines are capable of completing mitosis in the presence of belinostat. To force SAC activation in HDACi resistant cell lines, we used low dose microtubule targeting agents (MTA) vincristine and paclitaxel to induce maximal mitotic arrest with minimal cytotoxicity. The combination of these low dose MTAs and belinostat efficiently caused SAC failure, mitotic slippage, and apoptosis in a synergistic manner. A key mechanism associated with resistance to MTAs is their ability to induce aneuploid cell populations that survive and undergo endoreduplication. The addition of belinostat eliminated the accumulation of a vincristine-induced aneuploid population. Pan-caspase inhibition in conjunction with belinostat and vincristine co-treatment resulted in a sustained survival of the aneuploid population. Thus belinostat triggers apoptosis in the aneuploid cells to enhance the cytotoxic effects of vincristine. Our study identifies the use of low dose MTA/HDACi combination as a potential therapeutic strategy for treatment of relapsed or refractory DLBCL.

Citation Format: Aaron P. Havas, Anvi Bhakta, Kameron Rodrigues, Catharine L. Smith. Combining low dose microtubule targeting agents with belinostat potentiates cytotoxic response in HDACi resistant diffuse large b-cell lymphoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 275.
Abstract 2756: SMARCAD1 depletion enhances hyperthermia-mediated radiosensitization by decreasing resection and enhancing stalled replication forks
Authors: Chakraborty Sharmistha , Hunt Clayton R. , Hambarde Shashank , Mujoo Kalpana , Horikoshi Nobuo , Pandita Raj K. , Mattoo Abid , Teh Bin , Pandita Tej K.
Published: July 2016

Hyperthermia is the most effective chemo- and radio-sensitizer in use clinically for containing tumor growth. Hyperthermia is proposed to induce degradation of BRCA2, the protein involved in homologous recombination (HR) repair of DNA double strand breaks and, thus sensitizes cells to poly (ADP-ribose) polymerase (PARP)-1 inhibition. We and other laboratories have reported that hyperthermia inhibits DNA damage repair. Since HR includes single-strand annealing, gene conversion and break-induced replication, it is critical for DNA replication during recovery of stalled replication forks, but it is not yet clear how hyperthermia affects these important steps in HR.

Here we report that SMARCAD1 depletion increases hyperthermia induced cell death and chromosome damage in irradiated S-phase cells. Combined SMARCAD1 depletion and hyperthermia treatment decreased repair and recruitment of repairosome proteins to ISce-1 induced DSBs as well as decreased IR-induced repairosome foci formation. This effect was limited to S-phase cells, where homologous recombination is up regulated and the predominant pathway of DSB repair. Hyperthermia decreased the quantity of 5′ single stranded DNA intermediates at endonuclease-generated DNA break sites, an effect that was further decreased by SMARCAD1 depletion. Consistent with these results, simultaneous SMARCAD1 depletion and hyperthermia increased replication fork stalling and affected firing of new replication origins. The results presented here support a mechanism by which SMARCAD1 depletion and hyperthermia mediate radiosensitization through inhibition of the DNA resection step that precedes strand homology search during HR repair of IR-induced DSBs.

Citation Format: Sharmistha Chakraborty, Clayton R. Hunt, Shashank Hambarde, Kalpana Mujoo, Nobuo Horikoshi, Raj K. Pandita, Abid Mattoo, Bin Teh, Tej K. Pandita. SMARCAD1 depletion enhances hyperthermia-mediated radiosensitization by decreasing resection and enhancing stalled replication forks. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2756.
Abstract 2767: Expression of miR-1252 and its target PRR4 gene in laryngeal carcinoma
Authors: BUYRU NUR , EKIZOGLU SEDA , GULIYEV JALAL , KARAMAN EMIN , ULUTIN. TURGUT
Published: July 2016

Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer worldwide and includes neoplasias of the paranasal sinuses, the oral cavity, the trachea, the pharynx and the larynx. The most important risk factors are tobacco use, alcohol consumption and infection with human papillomavirus (HPV). Besides the exogenous risk factors, genetic factors may play a key role in the development of the HNSCC. Cancer of the larynx accounts for 25% of all head and neck malignancies.

The PRR4 (Prolin Rich Protein 4) gene is localized on human chromosome 12p13 and encodes a protein which is secreted from the acinar cells of the lacrimal gland, the submandibular gland, the parotis and the sublingual glands. Recent studies have demonstrated that PRR4 may play an important role as an antimicrobial protein to protect the ocular surface and the oral cavity. Additionally, it has been shown that PRR4 is highly expressed in the human submucosal glands.

microRNAs are small non-coding RNAs which regulate gene expression at the post-transcriptional level. They bind to their target RNA with their seed sequence complementary to the 3’UTR region. This interaction results in either up- or down-regulation of the target messenger RNA.

To understand the role of the PRR4 gene in laryngeal carcinogenesis, we investigated its mRNA expression levels in laryngeal tumor tissue and adjacent non-cancerous tissue samples from 90 patients by quantitative real-time PCR. As a complementary region between the seed sequence of miR-1252 and 3’UTR region of PRR4 gene exists, we also analyzed whether miR-1252 binds to this region and regulates the expression of PRR4.

We found that PRR4 gene expression was decreased in 65 (72.2%) and increased in 24 (26.7%) of 90 tumor tissues when compared to normal tissue. Statistically significant downregulation of the PRR4 mRNA was observed in laryngeal tumors (p<0.001). No significant correlation was found between PRR4 gene expression and clinicopathological parameters including age, sex, stage, histological grade and tumor location (p>0.05). We also analyzed miR-1252 expression levels in a subset of tumor samples. miR-1252 upregulation was observed only in 24% of tumor tissues compared to non-cancerous tissue. The miR-1252 level was same in the 62.5% of the remaining samples. We did not observe any correlation between the PRR4 and miR-1252 expression levels. Our results indicate that the PRR4 gene may have an impact in the progression of laryngeal carcinoma.

Citation Format: NUR BUYRU, SEDA EKIZOGLU, JALAL GULIYEV, EMIN KARAMAN, TURGUT ULUTIN. Expression of miR-1252 and its target PRR4 gene in laryngeal carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2767.