bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4304: Development of a new nucleoside triphosphate transporter (NTP) technology for rapid DNA labeling that measures cell cycle progression in live cancer cells
Authors: Asbrock Nick , Chu Vi , Su Kevin , Kraus Tomas
Published: August 2018

At its core, cancer is a disease of uncontrolled cell division. Mutations in different genes cause or accelerate cancer by increasing cell division rates or inhibiting cell proliferation control mechanisms such as apoptosis and tumor suppression. Traditional DNA incorporation cell proliferation assays that label nucleic acids (BrdU, EdU) have been popular but are limited by requiring cell fixation, high cost and lengthy protocols. Here, we have developed a new NTP transporter technology that allows the incorporation of Cyanine-3 fluorescently labeled dUTP's into DNA during the S-phase of the cell cycle to measure cell proliferation in live cancer cells (U2OS). Similar cell cycle profiles were produced using this new NTP transporter technology as analyzed by FACS analysis and live cell imaging vs. BrdU based cell proliferation assays. This technology will allow new insights into cancer cell proliferation and progression.

Citation Format: Nick Asbrock, Vi Chu, Kevin Su, Tomas Kraus. Development of a new nucleoside triphosphate transporter (NTP) technology for rapid DNA labeling that measures cell cycle progression in live cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4304.
Abstract 4313: Methylated BAF155 promotes cancer metastasis by cooperating with BRD4 to potentiate genes addicted to super-enhancers
Authors: Kim Eui-Jun , Wang Yidan , Lu Li , Rui Lixin , Zhong Xuehua , Wisinski Kari B. , Xu Wei
Published: August 2018

Triple-negative breast cancers (TNBC) lack the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). TNBC is the most aggressive breast cancer subtype and is often associated with distant metastasis, poor prognosis, and lack of targeted treatment options. The failure to identify a few genes driving metastasis through sequencing of paired tumors at primary and metastatic sites implies that epigenetic mechanisms may play important roles in TNBC metastasis. Recently, we found that an epigenetic enzyme coactivator associated arginine methyltransferase 1 (CARM1) is highly expressed in TNBC and its high expression correlates with poor prognosis. Subsequently we identified BRG1-Associated Factor 155 (BAF155), a component of SWI/SNF chromatin remodeling complex, as a novel CARM1 substrate. Transcriptome analyses of BAF155 methylation competent and defective cell lines identified many genes involved in regulating cancer metastasis are methyl-BAF155 targets. Methylation of BAF155 was found to promote metastasis in the TNBC xenografted mouse models. We generated a methyl-BAF155 antibody that could specifically detect methylated BAF155 (me-BAF155) by IHC and chromatin immunoprecipitation followed by sequencing (ChIP-seq). We mapped global me-BAF155 genomic association sites using ChIP-seq and discovered that me-BAF155 was highly enriched in super-enhancers (SEs), regulatory elements on chromatin that are known to drive high transcription of many oncogenes. SEs are known to recruit BRD4, a BET family bromodomain protein. Indeed, global me-BAF155 binding peaks greatly overlap with those of BRD4 binding sites. Treatment of TNBC cells with either BRD4 inhibitor JQ1 or CARM1 inhibitor TP-064 significantly reduced the expression of me-BAF155 target genes. Together our data suggest that me-BAF155 is an important epigenetic target for treatment of cancer metastasis in TNBC cells.

Citation Format: Eui-Jun Kim, Yidan Wang, Li Lu, Lixin Rui, Xuehua Zhong, Kari B. Wisinski, Wei Xu. Methylated BAF155 promotes cancer metastasis by cooperating with BRD4 to potentiate genes addicted to super-enhancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4313.
Abstract 4319: Epigenetic reprogramming associated with BRCA1 loss of function in ovarian cancer induces enhanced interferon gamma signaling
Authors: Cardenas Horacio , Pepin Jessica Thomes , Jiang Guanglong , Condello Salvatore , Nephew Kenneth P. , Liu Yunlong , Matei Daniela
Published: August 2018

Inactivating mutations of the breast cancer type 1 susceptibility protein (BRCA1) have been implicated in breast and ovarian cancer (OC) initiation. Having observed differential response of OC cells to histone deacetylase inhibitors (HDACi) dependent on the presence of a functional BRCA1, we mapped promoters marked by acetylation of lysine 9 or lysine 27 of histone H3 (H3K9ac, H3K27ac) by ChIP-sequencing, and measured gene expression by RNA-sequencing in the isogenic OC cell lines UWB1.289 carrying an inactivating mutation of BRCA1 (BRCA1-null) and UWB1.289 cells with restored BRCA1 gene (BRCA1+). Significant differences in promoter levels of H3K9 and H3K27 acetylation were associated with marked alteration of gene expression levels between BRCA-null and BRCA1+ cells and in response to the HDACi, entinostat. Pathway analyses revealed cellular movement, cellular development, cellular growth and proliferation, TGFβ1, TNF, and INF-γ among the top cellular/molecular functions and upstream regulators enriched by the absence of BRCA1 among H3K9ac differentially marked and differentially expressed genes. Importantly, the same pathways and regulators were enriched in response to entinostat in BRCA1+ cells, indicating that changes in gene expression affecting these functions and regulators in BRCA1-null cells depend on promoter-associated histone acetylation. Integrated analyses revealed that TGFβ1 and IFN-γ were also activated in BRCA1-null/or low vs. BRCA1-normal ovarian tumors in the TCGA database. IFN-γ target genes were upregulated at baseline and responded less to IFN-γ stimulation in BRCA1-null vs. BRCA1+ cells. Binding of HDAC1 to promoters of IFN-γ target genes was increased in BRCA1-null cells. Similarly, the BRCA1-null breast cancer cell line HCC1937 responded less to IFN-γ stimulation compared with HCC1937 cells in which BRCA1 was restored. The knockdown of STAT1, the main IFN-γ signaling transduction molecule, inhibited BRCA1+ cell proliferation, but did not affect BRCA1-null cells. We conclude that the transcriptome of BRCA1-null cells and tumors is altered through changes in histone acetylation affecting cancer-related pathways, including IFN-γ cellular responses. These changes could alter tumor progression in BRCA-null OC and impact response to immunotherapy.

Citation Format: Horacio Cardenas, Jessica Thomes Pepin, Guanglong Jiang, Salvatore Condello, Kenneth P. Nephew, Yunlong Liu, Daniela Matei. Epigenetic reprogramming associated with BRCA1 loss of function in ovarian cancer induces enhanced interferon gamma signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4319.
Abstract 4330: Pan-cancer analysis reveals m6A modification is functionally important in cancer
Authors: Zuo Zhixiang , Xie Yubin , Zheng Yueyuan , Nie Peng , Jiang Shuai , Zhao QI , Miao Yanyan , Ren Jian
Published: August 2018

N6-Methyladenosine (m6A) is the most abundant post-transcriptional modification in mammalian RNA molecules and has a critical role in many diseases, including cancer. However, the systematic investigation of the role of m6A in cancer is still lacking. We conducted a systematic analysis of the m6A-associated somatic mutations and expression of m6A writers and erasers in 3,401 cancer genomes of 12 cancer types from The Cancer Genome Atlas (TCGA) to find a potential role of the m6A machinery in cancer development. We revealed 1,973 genes with recurrent m6A-associated somatic mutations across multiple cancer types. We identified many known cancer genes, such as TP53, CTNNB1 and CDKN2A, as well as many candidate genes whose cancer-specific roles are less understood. Strikingly, liver cancer had the highest frequency of m6A-associated somatic mutations among the 12 cancer types, and these mutations were significantly enriched in metabolic pathways, such as retinol metabolism. In liver cancer, the abnormalities in m6A “writers” and m6A modification sites were significantly correlated with worse overall survival, independent of other clinical characteristics (e.g., tumor stage and race).

Implications: We for the first time consider somatic mutations relevant to the m6A modification sites to identify “driver” genes, thereby uncovering additional potential cancer “drivers” with rare mutations. Our study highlights m6A modifications as an important epigenetic mechanism of cancer development.

Citation Format: Zhixiang Zuo, Yubin Xie, Yueyuan Zheng, Peng Nie, Shuai Jiang, QI Zhao, Yanyan Miao, Jian Ren. Pan-cancer analysis reveals m6A modification is functionally important in cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4330.
Abstract 4343: Molecular identification of bladder cancer gene expression subtypes
Authors: Chu In-Sun , Song Bic-Na , Leem Sun-Hee
Published: August 2018

Bladder urothelial carcinoma (BLCA) comprises two main types: non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). To discovery the subtype of BLCA, we used gene expression data from 165 patient cohort (102 NMIBC, 63 MIBC). Three other gene expression data sets including the Sweden 1 cohort (97 NMIBC, 45 MIBC), the Sweden 2 cohort (213 NMIBC, 93 MIBC), and 408 MIBC sample from The Cancer Genome Atlas (TCGA) and 476 sample (460 NMIBC, 16 MIBC, the multicenter European UROMOL consortium). For selection of subtype-specific gene set, we used significance analysis of microarrays (SAM). Then, subtype-specific genes were trained by prediction analysis for microarrays (PAM) to build a classifier. Clustering analyses were applied to gene expression data of training set identified four molecular subtypes with different clinical outcomes. The majority of patients with class 1 were the low-grade NMIBC and associated with the prognosis of NMIBC, for cancer-specific survival (P =0.003, log-rank test). Class 2 patients, characterized by FGFR3 overexpression and downregulated immune pathways, showed the intermediate prognosis. Class 3 tumors showed high expression of cell-cycle genes and downregulated notch signaling pathway. Furthermore, high-grade NMIBC were predominantly found in class 3, indicating that NMIBC patients classified as class 3 would be more likely to progress to MIBC. Class 4 tumors, mainly composed of MIBC, were characterized by high expression of immune-related genes which is positively associated with potential response to immunotherapy. We further validated the BLCA subtypes in four independent data sets (n = 1,471), including the RNA-seq data set, by applying the 786-gene classifier onto the data sets. As expected, the progression rate of NMIBC patients classified as class 3 was significantly increased compared with other three classes in the RNA-seq data set (P < 0.001, log-rank test).

Citation Format: In-Sun Chu, Bic-Na Song, Sun-Hee Leem. Molecular identification of bladder cancer gene expression subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4343.
Abstract 4363: Pharmacologic targeting of Gq reveals new pathways in uveal melanoma
Authors: Onken Michael D. , Makepeace Carol M. , Wang Shiqi , Kaltenbronn Kevin M. , Kanai Stanley M. , Broekelmann Tom J. , Cooper John A. , Blumer Kendall J.
Published: August 2018

Constitutively active G protein α-subunits are oncogenic drivers of several cancers, most notably in uveal (eye) melanoma (UM), which have constitutively activating mutations in GNAQ(Gαq) or GNA11(Gα11) in over 90% of tumors. Therapeutic intervention by targeted inhibition of constitutively active Gα subunits in cancer has yet to be achieved. Here we show that constitutively active Gαq in UM cells can be targeted by the cyclic depsipeptide FR900359 (FR). FR inhibits GDP/GTP exchange allosterically to trap constitutively active Gαq in inactive GDP-bound Gαβγ heterotrimers, and allosteric inhibition of other Gα subunits can be achieved by introduction of an FR binding site. In UM cells driven by constitutively active Gαq, FR inhibits second messenger signaling, arrests proliferation and reinstates melanocytic differentiation. At higher doses, FR also induces apoptosis. FR has no effect on BRAF-driven UM cells. FR promotes UM cell differentiation by reactivating polycomb repressive complex 2 (PRC2)-mediated gene silencing, antagonized by a heretofore unrecognized effector system of constitutively active Gαq in UM. Constitutively active Gαq and PRC2 therefore provide important therapeutic targets for UM. Further, the development of FR analogs specific for other Gα subunit subtypes may provide novel therapeutic approaches for diseases driven by constitutively active Gα subunits or multiple G protein-coupled receptors where targeting a single receptor is ineffective.

Citation Format: Michael D. Onken, Carol M. Makepeace, Shiqi Wang, Kevin M. Kaltenbronn, Stanley M. Kanai, Tom J. Broekelmann, John A. Cooper, Kendall J. Blumer. Pharmacologic targeting of Gq reveals new pathways in uveal melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4363.
Abstract 440: Single-cell whole-genome sequencing reveals somatic mutation signatures in normal somatic cells predictive of cancer later in life
Authors: Dong Xiao , Zhang Lei , Lee Moonsook , Maslov Alexander Y. , Vijg Jan
Published: August 2018

Single-cell sequencing for analyzing DNA mutations across the genome in somatic tissues is critically important for studying development, cancer and aging. However, current procedures are prone to artifacts and to date a reliable protocol for single-cell somatic mutation analysis remains to be developed. We address the two largest sources of artifacts, i.e., DNA denaturation-related cytosine deamination and allelic bias-driven whole genome amplification errors. We first reconfigured multiple displacement amplification (MDA) into an efficient protocol for whole genome amplification of single cells without cytosine deamination artifacts, i.e., Single Cell MDA (SCMDA). We then developed a new single-cell SNV caller (SCcaller) that distinguishes real somatic mutations and amplification errors by utilizing a SNP-based localized estimate of allelic amplification bias. The procedure was validated by comparing SCMDA-amplified single cells with unamplified clones derived from single cells from the same population.

Using this highly accurate single-cell whole-genome sequencing method we analyzed human B lymphocytes from donors varying in age from birth to over 100 year, studying both genome distribution and functional impact of base substitution mutations. Mutations per cell were found to increase with age from less than 500 in cord blood to over 3,000 in cells from individuals over 100. While overall mutations were randomly distributed across the genome with all chromosomes equally affected, 24 hotspot regions were identified, five of which were part of immunoglobulin variable regions subject to somatic hypermutation. Age-related mutation accumulation was found to be significantly slower in genomic sequences directly involved in cellular function, such as exons and gene regulatory sequences. Still, on average, B lymphocytes from aged individuals contained 3-15 damaging mutations in the transcribed part of the exome identified by RNA-seq, plus 15-50 mutations in transcription factor binding sites identified by ATAC-seq. Analysis of the spontaneous mutation spectra in these normal cells revealed signatures similar to those previously found associated with B cell leukemia and other cancers. These results indicate that cancer risk is already part of age-related mutation accumulation in normal cells. Taken together, our single-cell sequencing method provides a firm foundation for analyzing cellular genetic heterogeneity in normal human tissues.

Citation Format: Xiao Dong, Lei Zhang, Moonsook Lee, Alexander Y. Maslov, Jan Vijg. Single-cell whole-genome sequencing reveals somatic mutation signatures in normal somatic cells predictive of cancer later in life [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 440.
Abstract 4401: Integrated genomic and functional microRNA analysis identifies miR-30-5p as a tumor suppressor and novel therapeutic nanomedicine in head and neck cancer
Authors: Saleh Anthony D. , Place Robert F. , Cheng Hui , Das Rita , Harris Thomas M. , Childs Geoffrey , Robertson Gordon A. , Pirollo Kathleen F. , Chang Esther H. , Chen Zhong , Waes Carter Van
Published: August 2018

We have developed an integrative approach to elucidate the functional role of deregulated microRNAs (miRs) and identify candidates for miR replacement therapy in cancer, applied here to head and neck squamous cell carcinomas (HNSCC). Our method involves integration of results from TCGA and other validation databases of genetic and expression data, including: miR expression, mRNA expression, copy number variation, DNA methylation. This data is then intersected with functional in vitro genome-wide miR screening for anti-proliferative miR mimics. We report that the miR-30-5p family is commonly repressed and correlates with overexpression of a broad network of proliferative and metastasis-related oncogenic mRNAs, including the growth receptors EGFR, MET and IGF1R. We show that re-expression of miR-30a-5p repressed this gene program, downstream signaling, proliferation, migration, and invasion in vitro. We have developed a chemically modified mimic of miR-30-5p with 50x improved stability in human serum, and 5X improvement in IC50 in vitro by XTT assay. We have formulated our novel miR-30a-5p mimic into Transferrin Receptor targeted nanoparticles which strongly inhibited HNSCC xenograft tumor growth, and regulated miR-30-5p family targets in vivo. Together with data linking decreased miR-30 family expression with DNA copy loss and promoter hypermethylation, and clinical disease-specific survival, for the first time, we have reported a more global picture of the function of this important tumor suppressor and identified a subset of patients that may benefit from miR replacement therapy with our novel miR-30-5p based nanomedicine.

This research was supported by NIDCD intramural projects ZIA-DC-000073, 74, and NCI grant U43CA22156701.

Citation Format: Anthony D. Saleh, Robert F. Place, Hui Cheng, Rita Das, Thomas M. Harris, Geoffrey Childs, Gordon A. Robertson, Kathleen F. Pirollo, Esther H. Chang, Zhong Chen, Carter Van Waes. Integrated genomic and functional microRNA analysis identifies miR-30-5p as a tumor suppressor and novel therapeutic nanomedicine in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4401.
Abstract 4403: Development of 5-FU modified tumor suppressor miRNAs as a platform for miRNA based cancer therapeutics
Authors: Fesler Andrew , Guo Shixiang , Ye Zachary , Godwin Matthew , Wang Hyaizha , Ju Jingfang
Published: August 2018

Despite extensive efforts to develop effective delivery technologies for nucleic acid based therapeutic agents, it remains a challenge to deliver therapeutic miRNAs to cancer cells. We have recently developed a novel approach to modify miRNAs by replacing uracil with 5-Fluorouracil (5-FU) in the guide strand of the miRNA molecule (e.g. miR-129, miR-15a). This modification combines the power of 5-FU with tumor suppressor miRNAs to create a potent, and multi-targeted therapeutic molecule without altering the function of the native miRNA. miRNA with this modification have a number of unique features such as retaining target specificity, vehicle free delivery, enhanced potency, and stability. To demonstrate the general applicability of this approach to other tumor suppressor miRNAs, in this study, we have screened a number of miRNA mimics incorporating this modification (e.g. miR-215, miR-140, miR-200c, miR-194, let-7g, miR-502, miR-506) in several major cancer types including colon cancer, pancreatic cancer, and breast cancer. Our results show that the 5-FU modified miRNAs are more potent (low nM range) at inhibiting cancer cell proliferation than the native miRNAs. More importantly, the miRNA mimics are able to eliminate chemoresistant cancer stem like cells. These modified mimics can be delivered into cancer cells without the aid of a delivery vehicle. The modification also did not alter target specificity of the miRNAs, a critical feature of these miRNA mimics. This work demonstrates the potential of this modification to be applied to a broad spectrum of miRNAs in different cancers, and represents a significant advancement in the development of therapeutic miRNAs for cancer treatment.

Citation Format: Andrew Fesler, Shixiang Guo, Zachary Ye, Matthew Godwin, Hyaizha Wang, Jingfang Ju. Development of 5-FU modified tumor suppressor miRNAs as a platform for miRNA based cancer therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4403.
Abstract 4417: MicroRNA 181a-5p reprogrammed glucose and lipid metabolism in lung cancer though regulating SIRT1 and ACSL4
Authors: Son Ji Woong , Kim Seul-Gi , Jeong In Beom , Kwon Sun Jung
Published: August 2018

Changes in metabolism are key contributors to tumorigenesis and metastasis. Micro RNAs (miRNA) play critical roles in glucose and lipid metabolism. In previous studies, miRNA 181a-5p (miR-181a-5p) was shown to be a significant component in down regulation of lung cancer tissue and mesenchymal-like lung cancer cell lines. To define the role of endogenous miR-181a-5p in cancer metabolism, we performed assays for luciferase, Lactate Dehydrogenase (LDH), glucose uptake and mitochondrial ATP synthase inhibitor. It was demonstrated that miR-181a-5p inhibited aerobic glycolysis and lipid metabolism and overexpression decreased LDH and lipid content in lung cancer. Furthermore, the overexpression of miR-181a-5p diminished invasion and migration by inhibition of Sirtuin 1 (SIRT1) and acyl-CoA synthetase long-chain family member 4 (ACSL4). Together these findings suggest that miR-181a-5p might be involved with reprograming lung cancer metabolism.

Citation Format: Ji Woong Son, Seul-Gi Kim, In Beom Jeong, Sun Jung Kwon. MicroRNA 181a-5p reprogrammed glucose and lipid metabolism in lung cancer though regulating SIRT1 and ACSL4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4417.
Abstract 4420: MiR-182 suppresses invadopodia formation and metastasis in non-small cell lung cancer by targeting cortactin
Authors: Li Yongwen , Zhang Hongbing , Liu Hongyu , Chen Jun
Published: August 2018

Metastasis is the leading cause of cancer mortality and is a major hurdle for lung cancer treatment. Invadopodia, which are cancer-specific protrusive structures, play a crucial role in the metastatic cascade through degradation of the basement membrane and surrounding stroma, but the exact mechanism of regulation is not yet fully understood. In this study, we show that cortactin (CTTN), an important component of invadopodia, is upregulated in lung cancer tissues and is a marker of poorer prognosis in human NSCLC. Phorbol 12,13-dibutyrate and hepatocyte growth factor can induce CTTN expression and motility, as well as invadopodia formation in non-small cell lung cancer (NSCLC). MicroRNA-182 (miR-182) suppresses metastasis and invadopodia formation by targeting CTTN in NSCLC. qRT-PCR results showed that CTTN expression was inversely correlated with expression of miR-182. miR-182/CTTN suppresses invadopodia formation of lung cancer cells via suppression of the Cdc42/N-WASP pathway. Furthermore, miR-182 negatively regulates invadopodia function and suppresses extracellular matrix degradation in lung cancer cells by inhibiting CTTN. In conclusion, our results demonstrated that miR-182 targets CTTN in NSCLC and suppresses lung cancer invadopodia formation and thus suppresses lung cancer metastasis, suggesting a therapeutic application of miR-182 in NSCLC.

Citation Format: Yongwen Li, Hongbing Zhang, Hongyu Liu, Jun Chen. MiR-182 suppresses invadopodia formation and metastasis in non-small cell lung cancer by targeting cortactin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4420.
Abstract 4422: miR-125b mediates oral cancer suppression by targeting the antioxidative gene peroxiredoxin like 2A (PRXL2A)
Authors: Chen Yi-Fen , Wei Yun-Yen , Yang Cheng-Chieh , Liu Chung-Ji , Chang Kuo-Wei , Lin Shu-Chun
Published: August 2018

Oral squamous cell carcinoma (OSCC) is a globally prevalent malignancy. The molecular mechanisms of this cancer remain to be elucidated to acquire further interception. Peroxiredoxin like 2A (PRXL2A) was named FAM213A previously, has been reported an antioxidant protein that protects cells from oxidative stress. Our previous study has identified the association between PRXL2A up-regulation in OSCC and the worse prognosis of patients. MicroRNAs (miRNAs) are small non-coding RNAs involved in the modulation of physical or pathological properties. miR-125 family genes drive pluripotent regulation in a wide variety of cancers. In this study, we specified the oncogenic eligibility of PRXL2A and clarified miR-125b as its upstream regulator. Down-regulation of miR-125b was observed in OSCC tumors. Lower miR-125b expression in OSCC tissues defined the worse patient prognosis. Reporter assays validated that PRXL2A as a direct target of miR-125b. Exogenous miR-125b expression resulted in the decreased oxidative stress, increased drug sensitivity, and suppressor activities, which was consistent with the knockout of PRXL2A gene in OSCC cells. That the suppressor activities of miR-125b being rescued by PRXL2A denoted the existence of miR-125b-PRXL2A regulatory axis in OSCC pathogenesis. Knockout of PRXL2A drastically attenuated the tumorigenic potential of OSCC cells. Overall, this study proposes novel clues demonstrating that the down-regulation of miR-125b suppressor underlies the PRXL2A up-regulation in OSCC, and this protects tumor cells from oxidative stress leading to the worse patient survival.

Citation Format: Yi-Fen Chen, Yun-Yen Wei, Cheng-Chieh Yang, Chung-Ji Liu, Kuo-Wei Chang, Shu-Chun Lin. miR-125b mediates oral cancer suppression by targeting the antioxidative gene peroxiredoxin like 2A (PRXL2A) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4422.
Abstract 4423: MiR551b-mediated Oncostatin M signaling in breast cancer
Authors: Geethadevi Anjali , Parashar Deepak , Ragle-Aure Miriam , Nair Bindu , Lu Yiling , Kristensen Vessela N. , You Ming , Sood Anil K. , Mills Gordon B. , Pradeep Sunila , Raghavan Pradeep Chaluvally
Published: August 2018

We have previously demonstrated that an oncogenic microRNA miR551b-3p (also known as miR551b) regulates STAT3 transcription thereby enhancing tumor growth and metastasis in ovarian cancer. Herein, we have identified that Oncostatin M (OSM) is upregulated through STAT3-driven transcription, which plays an important role in promoting migration and invasion of breast cancer cells. The purpose of this study was to evaluate the role of miR551b mediated STAT3 activation and the precise mechanism that regulates OSM-Receptor (OSMR) signaling for breast cancer growth and metastasis. MDA-MB231 cells were either overexpressed or silenced with miR551b and anti-miR551b respectively and the effects on proliferation, migration/invasion (Matrigel transwell assay), wound healing and expression of OSMR and its downstream targets (Western blotting, Quantitative RT-PCR) were assessed. Our data demonstrate that miR551b promoted survival, proliferation, invasion and migration and epithelial to mesenchymal transition (EMT) and spheroid formation of breast cancer cells. Our results also show that miR551b-mediated STAT3 activation upregulated the components of OSMR signaling through elevated expression of OSMR, Interleukin 31 receptor-alpha (IL31RA) and their ligands Oncostatin (OSM) and IL31 thereby inducing phosphorylation of STAT3 for tumor cell proliferation, migration and invasion. Conversely, anti-miR551b reduced the expression of OSMR, IL31R and their ligands OSM and IL31 as well as the phosphorylation of STAT3. Briefly, our results provide the first report indicating that miR551b regulates OSMR expression by activating STAT3 and thereby promoting tumor cell growth and metastasis in breast cancer cells through autocrine feed-forward signaling loop.

A.G, D.P., contributed equally.

Citation Format: Anjali Geethadevi, Deepak Parashar, Miriam Ragle-Aure, Bindu Nair, Yiling Lu, Vessela N. Kristensen, Ming You, Anil K. Sood, Gordon B. Mills, Sunila Pradeep, Pradeep Chaluvally Raghavan. MiR551b-mediated Oncostatin M signaling in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4423.
Abstract 444: ER Stress marker GRP78 is not expressed on ER-/PR-/Her2- human breast cancer cell surface or secreted
Authors: Serrano Jesus E. , Rivera-Ruiz Andrea , Baksi Krishna , Banerjee Dipak K.
Published: August 2018

GRP78 (a Mr 78kDa calcium dependent glucose binding protein) located in ER lumen. It functions as ER chaperone and translocates proteins for glycosylation at the asparagine residue present in the sequon Asn-X-Ser/Thr (i.e., N-linked glycosylation).  This important biochemical event is essential for glycoprotein folding and function. When targeted in ER-/PR-/HER2+ breast tumor in athymic nude mice with the N-glycosylation inhibitor tunicamycin, the cancer growth was reduced ~55% in three weeks. Paraffin sections of the tumor exhibited reduced N-glycan level, and reduced angiogenesis but increased GRP78 expression in microvasculature as well as in the tumor tissue (J. Biol. Chem. 286, 29127–29138, 2011). This supported the presence of ER stress.  We have now evaluated the effect of tunicamycin on the proliferation of metastatic ER-/PR-/HER2- (MDA-MB-231) and non-metastatic ER+ (MCF-7) human breast cancer cells. Tunicamycin inhibited proliferation of both cells types in a time and dose-dependent manner.   Interestingly, GRP78 expression (protein and mRNA) was higher in tunicamycin (1.0 µg/ml) treated MDA-MB-231 and in MCF-7 cells and supported by both Western blotting and qPCR.   Since GRP78 is an ER stress marker, so we have followed its intracellular localization by immunofluorescence microscopy after treating the cancer cells with tunicamycin as well as after subjecting them to various stress conditions.  We have used unfixed cells and stained with either FITC-conjugated Concanavalin A (Con A), or Texas-red conjugated wheat germ agglutinin (WGA) or with anti-GRP antibody. There were expression of N-glycans but not GRP78. GRP78 however became detectable after permeabilization of cells with a brief exposure to ice-cold methanol. GRP78 was not detected in the conditioned media of the cancer cell but a high level of MMP-1 did.  We have therefore, concluded that GRP78 is expressed neither on the outer-leaflet of the (ER-/PR-/HER2-) human breast cancer cells nor it is secreted into the culture media during tunicamycin-induced ER stress. This is obviously, contradicted the current dogma that GRP78 expression on the tumor cell surface interferes with the cancer therapeutic(s) and make them as tumor promoters and not tumor suppressors. Our study, thus, suggests strongly that anti-angiogenic and anti-tumorigenic action of tunicamycin can be modeled to develop next generation cancer therapy, i.e., glycotherapy for treating breast tumor and all other sold tumors. Supported in part by the university funds and NIH/NIMHD G12MD007583 (KB).

Citation Format: Jesus E. Serrano, Andrea Rivera-Ruiz, Krishna Baksi, Dipak K. Banerjee. ER Stress marker GRP78 is not expressed on ER-/PR-/Her2- human breast cancer cell surface or secreted [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 444.
Abstract 446: HSP90 inhibitors disrupt a transient HSP90-HSF1 interaction and identify a noncanonical model of HSP90-mediated HSF1 regulation
Authors: Tigue Megan L. , Kijima Toshiki , Prince Thomas L. , Yim Kendrick H. , Schwartz Harvey , Beebe Kristin , Lee Sunmin , Budzynski Marek A. , Williams Heinric , Trepel Jane B. , Sistonen Lea , Calderwood Stuart , Neckers Len
Published: August 2018

Heat shock factor 1 (HSF1) is an evolutionarily conserved transcription factor that initiates the cytoprotective heat shock response (HSR) and mediates a cancer-specific transcriptional program, which is comprised of over 500 genes and has been associated with poor clinical outcomes. HSF1 is thought to be regulated by molecular chaperones, including Heat Shock Protein 90 (HSP90). The purpose of our study was to describe the interactions between molecular chaperones, such as HSP90 and HSP70, and HSF1 and to determine the mechanism(s) by which HSP90 inhibitors promote the HSR in mammalian cells. Using a combination of techniques including IP-WB, ChIP, and RT-qPCR analysis, we demonstrated that HSP90 binding to HSF1 depends on HSP90 conformation and is only readily visualized for the ATP-dependent, N-domain dimerized chaperone, a conformation rarely sampled by mammalian HSP90. We also showed that ATP-competitive, N-domain targeted HSP90 inhibitors disrupt this interaction and enhance HSF1 phosphorylation, resulting in the increased duration of HSF1 occupancy of the hsp70 promoter and significant prolongation of both the constitutive and heat-induced HSF1 transcriptional activity. While our data do not support a role for HSP90 in sequestering HSF1 monomers to suppress HSF1 transcriptional activity, as has been previously proposed, our findings do identify a noncanonical role for HSP90 in providing dynamic modulation of HSF1 activity by participating in removal of HSF1 trimers from heat shock elements in DNA, thus terminating the heat shock response.

Citation Format: Megan L. Tigue, Toshiki Kijima, Thomas L. Prince, Kendrick H. Yim, Harvey Schwartz, Kristin Beebe, Sunmin Lee, Marek A. Budzynski, Heinric Williams, Jane B. Trepel, Lea Sistonen, Stuart Calderwood, Len Neckers. HSP90 inhibitors disrupt a transient HSP90-HSF1 interaction and identify a noncanonical model of HSP90-mediated HSF1 regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 446.
Abstract 4463: Loss of APC mediates doxorubicin resistance in breast cancer cells
Authors: Stefanski Casey D. , Keffler Kaitlyn , McClintock Stephanie , Prosperi Jenifer R.
Published: August 2018

Resistance to chemotherapy is one of the leading causes of breast cancer related deaths. Understanding the molecular basis for chemoresistance is essential for the advancement of novel therapeutic approaches to ultimately improve patient outcomes. The Adenomatous Polyposis Coli (APC) tumor suppressor is either mutated or hypermethylated in up to 70% of sporadic breast cancer; however, little is known about how loss of APC contributes to chemoresistance. Using the ApcMin/+ mouse crossed to the Polyoma middle T antigen (PyMT) transgenic model, we demonstrated that APC loss decreased cisplatin and doxorubicin-induced apoptosis. We previously showed that loss of APC in MMTV-PyMT;ApcMin/+ cells induced STAT3-activation resulting in an enhanced tumor initiating cell (TIC) population and increased multidrug resistance protein 1 (MDR1) expression. Therefore, we hypothesized that APC loss increased MDR1 activity and decreased doxorubicin-mediated DNA damage, ultimately preventing cell death. Using calcein incorporation, we first demonstrated that APC loss increased MDR1 activity which was normalized to WT control levels by the MDR1 inhibitor, Valspodar. We next showed that MDR1 inhibition in MMTV-PyMT;ApcMin/+ cells could restore doxorubicin-mediated apoptosis to that of MMTV-PyMT;Apc+/+ treated cells. Due to STAT3 inducing MDR1 activity and TIC population, MDR1 inhibition in MMTV-PyMT;ApcMin/+ cells was also shown to reduce the TIC population. In addition, we are investigating the effect of APC loss on DNA damage repair pathways. Preliminary studies have shown decreased γH2AX in MMTV-PyMT;ApcMin/+ cells treated with doxorubicin, suggesting a decrease in DNA damage. Downstream signaling of γH2AX, measured by phosphorylation of ATM, also demonstrated decreased DNA damage with ongoing studies measuring phosphorylation of ATR. Due to APC binding to topoisomerase IIα (topo IIα), a target of doxorubicin, the activity of topo IIα was measured to address whether this decreased DNA damage was attributed to impaired topo IIα activity or decreased intracellular doxorubicin due to increased MDR1 efflux. Future studies will investigate whether MDR1 inhibition in combination with doxorubicin will reduce tumor burden in vivo. Taken together, APC loss mediates doxorubicin resistance via enhanced MDR1 activity and altered DNA damage repair pathways demonstrating the potential use of combination therapy to overcome resistance to chemotherapy.

Citation Format: Casey D. Stefanski, Kaitlyn Keffler, Stephanie McClintock, Jenifer R. Prosperi. Loss of APC mediates doxorubicin resistance in breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4463.
Abstract 4464: CPEB-2 is a tumor-suppressor gene in human breast cancer
Authors: Lala Peeyush K. , Tordjman Joshua , Amiri Mehdi , Hasan Asma , Hess David , Majumder Mousumi
Published: August 2018

We found that expression of cyclooxygenase (COX)-2 promotes breast cancer progression by multiple mechanisms, including stimulation of cancer cell proliferation, migration, invasiveness, epithelial-to-mesenchymal transition (EMT), angiogenesis, lymphangiogenesis and induction of stem-like cells (SLC). Through combined gene expression and microRNA microarray analyses of COX-2-transfected MCF-7 cells, we identified two oncogenic miRNAs, miR-526b and miR-655, up-regulated by COX-2. They collectively target 13 tumour suppressor-like genes down-regulated by COX-2, of which Cytoplasmic Polyadenylation Element-Binding Protein -2 (CPEB-2) was the single common target, whose function is unclear in breast cancer. CPEB-2 is known to downregulate mesenchymal transcription factor TWIST1 and translation of HIF1α. CPEB-2 has multiple isoforms (A-F), of which a high B: A isoform ratio was reported to confer anoikis-resistance, a metastatic phenotype, in breast cancer cells. We found that CPEB-2 expression was inversely correlated with COX-2 or the microRNAs miR-526b and miR-655 in breast cancer cell lines; it was very high in a non-tumorigenic mammary epithelial cell line MCF10A.To define its functional roles we knocked out CPEB-2 in MCF10A cells by CRISPR/Cas9-double nickase approach. CPEB-2-KO cells exhibited oncogenic phenotypes in vitro: increased proliferation, migration, invasion, EMT phenotype (decreased E-Cadherin, increased Vimentin, N-cadherin, SNAI1, and ZEB1) and SLC properties (increased spheroid formation and SLC-linked markers). P53 protein was found to be a novel translationally- regulated target of CPEB-2. CPEB-2KO cells, but not wild-type cells, produced lung colonies upon intravenous injection and orthotopic tumors (identified by HLA staining) upon implantation at mammary sites in NOD/SCID/IL2Rϒ-null mice. In human breast cancer tissues, compared to non-tumour breast tissues, isoform A/E of CPEB2 revealed a lower expression in HER2+ breast cancer samples, suggesting that CPEB-2A/E are the tumour-suppressor isoforms. These findings demonstrate that CPEB-2 is a tumour suppressor gene in breast cancer. (Supported by the OICR and the NSERC)

Citation Format: Peeyush K. Lala, Joshua Tordjman, Mehdi Amiri, Asma Hasan, David Hess, Mousumi Majumder. CPEB-2 is a tumor-suppressor gene in human breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4464.
Abstract 447: A novel proteotoxic combination therapy for EGFR+ and HER2+ cancers
Authors: Wang Mengxiong , Ferreira Renan , Law Mary , Yaaghubi Elham , Heldermon Coy , Castellano Ronald , Law Brian
Published: August 2018

EGFR and/or HER2 are frequently overexpressed oncoproteins in HER2+ breast cancer, Triple Negative Breast Cancer (TNBC), and Inflammatory Breast Cancer (IBC). However, EGFR and/or HER2 targeting agents have failed to make major advances in improving survival for these cancer patients, largely because these cancers frequently develop resistance to these drugs. The identification of novel treatment strategies is critically needed. Overexpression of EGFR and/or HER2 presents a severe burden to the secretary pathway, as HER-family proteins EGFR, HER2, HER3 share conserved extracellular cysteine-rich and proline-rich repeats that form numerous disulfide bonds and control cis-trans isomerization in the protein folding processes. We demonstrated that the disulfide bond disrupting Agents (DDAs) selectively killed EGFR+ and/or HER2+ breast cancer cells in vitro and decreased tumor growth of HER2+ cancer in a xenograft mouse model. DDA-dependent anti-cancer actions resulted from downregulation of EGFR/HER2/HER3, induction of AKT dephosphorylation, and activation of Endoplasmic Reticulum (ER) stress. We also investigated a novel proteotoxic combination therapy employing DDAs and Proline Isomerase Inhibitors (PIIs) in treating breast cancers. PIIs potentiated the efficacy of DDAs in downregulating EGFR/HER2/HER3 levels and initiating ER stress, and the combination was highly synergistic in reducing EGFR+ and/or HER2+ breast cancer cell viability. Importantly, the combination of DDAs and PIIs overcame single drug resistance, significantly decreased tumor volumes and increased the survival of xenograft mice. Evidence that the drug combination was effective against metastatic breast cancer cells is also provided.

Citation Format: Mengxiong Wang, Renan Ferreira, Mary Law, Elham Yaaghubi, Coy Heldermon, Ronald Castellano, Brian Law. A novel proteotoxic combination therapy for EGFR+ and HER2+ cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 447.
Abstract 4470: Loss of ARL6IP4 induces the epithelial mesenchymal transition in breast cancer metastasis by transcriptionally phosphorylating NF-kB
Authors: Park Mi Kyung , Jang Ji Yun , Byun Hyun Jung , Kim Hyun Ji , Lee Ho , Lee Chang Hoon
Published: August 2018

The epithelial mesenchymal transition EMT is the major mechanism involved in cancer metastasis. During EMT, epithelial cells lose cell-cell adhesions to gain mesenchymal-like properties, such as increased invasive abilities. The function of ARL6IP4 in the EMT of breast cancers has not yet been studied. Here we show that the ARL6IP4 controls EMT in breast cancer metastasis. we demonstrate that the role of ARL6IP4 by analysis of ARL6IP4 conditional knockout animals, various in vitro and in vivo models of EMT and metastasis, a mouse mammary tumor virus-polyoma middle T antigen (MMTV-PyMT) model of breast cancer metastasis. We identified that loss of ARL6IP4 phosphorylated of nuclear factor-κB (NF-κB) by increasing the expression of the SNAIL and ZEB1 EMT transcription factors (EMT-TFs). Taken together, our findings establish that ARL6IP4 is a potential tumor suppressor by regulation the phosphorylation of NF-κB.

Citation Format: Mi Kyung Park, Ji Yun Jang, Hyun Jung Byun, Hyun Ji Kim, Ho Lee, Chang Hoon Lee. Loss of ARL6IP4 induces the epithelial mesenchymal transition in breast cancer metastasis by transcriptionally phosphorylating NF-kB [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4470.
Abstract 4496: Myofibroblast-secreted follistatin-like 1 promotes hepatocellular carcinoma formation and metastasis
Authors: Li Natalie Tsz Wai , Tong Man , Zhou Lei , Ning Wen , Lo Chung-Mau , Man Kwan , Lee Terence Kin-Wah , Ma Stephanie Kwai-Yee
Published: August 2018

Hepatocellular carcinoma (HCC) develops in the setting of fibrosis/cirrhosis, a progressive process in which chronic inflammation and hepatocellular regeneration result in the malignant transformation of hepatocytes. Enrichment of stromal myofibroblasts in this pathological stage is commonly observed, which constitutes the bulk of the tumor microenvironment and contributes to disease progression. Cancer cells are regulated by signals generated intrinsically and extrinsically from the tumor microenvironment. Targeting critical factors involved in this process may offer important therapeutic opportunities. Follistatin-like 1 (FSTL1) has been widely reported as a pro-inflammatory mediator in different fibrosis-related and inflammatory diseases. Here, we report that FSTL1 is either absent or expressed at very low levels in HCC cells, but preferentially secreted from the myofibroblasts of peri-tumor liver and HCC tissue as well as in the liver following acute injury. FSTL1 was found to co-localize and positively correlate with α-SMA, marker of myofibroblasts, in both human HCC as well as in a DEN+CCl4-induced HCC mouse model. High FSTL1 expression in myofibroblast FAP+ cells (FAP+/FSTL1high) also correlated with advanced TNM stages as compared to HCC patients in the FAP+/FSTL1low subgroup. Functional investigations revealed that FSTL1 can induce HCC cell proliferation, metastasis and sorafenib resistance; while FSTL1 attenuation by neutralizing antibody elicited the opposite effects. These observations were further validated in HCC patient-derived organoid cultures in which FSTL1 can enhance the metastatic effect of the cells. Transcriptome sequencing analysis is now currently underway to delineate the underlying molecular mechanism by which myofibroblast-secreted FSTL1 drives carcinogenesis and tumor progression in HCC.

Citation Format: Natalie Tsz Wai Li, Man Tong, Lei Zhou, Wen Ning, Chung-Mau Lo, Kwan Man, Terence Kin-Wah Lee, Stephanie Kwai-Yee Ma. Myofibroblast-secreted follistatin-like 1 promotes hepatocellular carcinoma formation and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4496.