bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5227: Suppressive role of elevated estrogen on endometrial carcinogenesis
Authors: Asaka Ryoichi , Miyamoto Tsutomu , Ida Koichi , Takeuchi Hodaka , Ando Hirofumi , Yamada Yasushi , Mvunta David Hamisi , Kobara Hisanori , Kashima Hiroyasu , Shiozawa Tanri
Published: August 2018

Background: Although estrogen has been regarded as a risk factor for endometrial carcinoma, its concentration-dependent carcinogenetic effects remain unclear, because most endometrial carcinomas occur in post-menopausal women, whose serum estrogen levels are relatively low. Because impaired mismatch repair (MMR) was reportedly crucial in the early stages of endometrial carcinogenesis, we focused on the relationship between various estrogen concentration and MMR activity in normal and malignant endometrial glandular cells. In those cells, we reported that the protein and mRNA expression of both hMLH1 and hMSH2, the key factors of MMR, were up-regulated by estrogen stimulation. In addition, we demonstrated that the estrogen stimulation enhanced the MMR activity in those cells using in vitro MMR assay with the M13mp2 phage heteroduplex DNAs and that the proliferating cells without hMLH1/hMSH2 expressions implying “high risk” cells were more frequently observed under relative-low estrogen concentrations. In this study, to further confirm the role of E2 in vivo, we employed a mouse endometrial carcinoma model induced by intra-uterine injection of a carcinogen, N-methyl-N-nitrosourea (MNU) under various E2 concentrations.

Methods: MNU was injected into the uterine cavity of 29 CD-1 mice at 6 weeks of age, and E2 was administered by pellets or orally. Uteri were removed for histological examinations 24 weeks later, and serum E2 levels were measured. The immunohistochemical expression of MMR proteins in uterine epithelia was investigated.

Results: Of 29 mice, 8, 8, 8, and 5 showed atrophic, normal, hyperplastic, and carcinomatous endometria, respectively. The mean E2 levels of each group were 0.2pg/ml, 3.8pg/ml, 190.0pg/ml, and 6.7pg/ml, with significant differences. The expression of the MMR proteins was stronger in mice with elevated E2.

Conclusions: Elevated E2 levels preferentially induced endometrial hyperplasia rather than carcinoma, and this may be mediated by MMR proteins. These results indicate that modest E2 is needed, whereas elevated E2 levels are not necessarily advantageous for carcinogenesis, suggesting the importance of low-chronic (un-opposed) estrogen in human endometrial carcinogenesis.

Citation Format: Ryoichi Asaka, Tsutomu Miyamoto, Koichi Ida, Hodaka Takeuchi, Hirofumi Ando, Yasushi Yamada, David Hamisi Mvunta, Hisanori Kobara, Hiroyasu Kashima, Tanri Shiozawa. Suppressive role of elevated estrogen on endometrial carcinogenesis [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 5227.
Abstract 5240: Functional and therapeutic significance of ESR1 gene fusions in breast cancer
Authors: Lei Jonathan T. , Shao Jieya , Zhang Jin , Iglesia Michael , Chan Doug W. , Cao Jin , Anurag Meenakshi , Singh Purba , He Xiaping , Kosaka Yoshimasa , Matsunuma Ryoichi , Crowder Robert , Hoog Jeremy , Phommaly Chanpheng , Goncalves Rodrigo , Romalho Susana , Peres Raquel M. , Punturi Nindo , Schmidt Cheryl , Bartram Alex , Jou Eric , Lai W V. , Hampton Oliver , Rogers Anna , Tobias Ethan , Parikh Poojan , Davies Sherri R. , Li Shunqiang , Ma Cynthia X. , Suman Vera , Hunt Kelly K. , Watson Mark A. , Hoadley Katherine A. , Thompson E A. , Chen Xi , Kavuri Shyam M. , Creighton Chad J. , Maher Christopher A. , Perou Charles M. , Haricharan Svasti , Ellis Matthew J.
Published: August 2018

RNA sequencing detects estrogen receptor alpha gene (ESR1) fusion transcripts in estrogen receptor positive (ER+) breast cancer but their role in disease pathogenesis remains unclear. Herein we examined multiple in-frame and out-of-frame ESR1 fusions and found only two, both identified in advanced endocrine treatment resistant disease, encoded stable and functional in-frame fusion proteins. In both examples, ESR1-e6>YAP1 and ESR1-e6>PCDH11X, the N-terminal, DNA binding and dimerization motifs encoded by exons 2-6 were fused to C-terminal sequences from the partner gene. Functional properties included estrogen-independent growth, constitutive expression of ER target genes, anti-estrogen resistance, induction of cellular motility in vitro and the development of lung metastasis in vivo. Chromatin immunoprecipitation and RNA sequencing experiments showed both fusions uniquely activated a metastasis-associated transcriptional program. ESR1-e6>YAP1 and ESR1-e6>PCDH11X-induced growth remained sensitive to a CDK4/6 inhibitor, palbociclib, and a patient-derived xenograft (PDX) expressing the ESR1-e6>YAP1 fusion was also responsive. Transcriptionally active ESR1 fusions therefore trigger both endocrine therapy resistance and metastatic progression explaining the association with fatal disease progression, although CDK4/6 inhibitor treatment is predicted to be effective.

Citation Format: Jonathan T. Lei, Jieya Shao, Jin Zhang, Michael Iglesia, Doug W. Chan, Jin Cao, Meenakshi Anurag, Purba Singh, Xiaping He, Yoshimasa Kosaka, Ryoichi Matsunuma, Robert Crowder, Jeremy Hoog, Chanpheng Phommaly, Rodrigo Goncalves, Susana Romalho, Raquel M. Peres, Nindo Punturi, Cheryl Schmidt, Alex Bartram, Eric Jou, W V. Lai, Oliver Hampton, Anna Rogers, Ethan Tobias, Poojan Parikh, Sherri R. Davies, Shunqiang Li, Cynthia X. Ma, Vera Suman, Kelly K. Hunt, Mark A. Watson, Katherine A. Hoadley, E A. Thompson, Xi Chen, Shyam M. Kavuri, Chad J. Creighton, Christopher A. Maher, Charles M. Perou, Svasti Haricharan, Matthew J. Ellis. Functional and therapeutic significance of ESR1 gene fusions 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 5240.
Abstract 5247: Aspirin use and estrogen receptor-negative breast cancer risk in African American women
Authors: Bertrand Kimberly A. , Bethea Traci N. , Gerlovin Hanna , Coogan Patricia , Adams-Campbell Lucile L. , Rosenberg Lynn , Palmer Julie R.
Published: August 2018

Introduction: Use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has been hypothesized to be associated with reduced risk of breast cancer; however, results of epidemiological studies have been mixed. Further, few previous studies investigated these associations among African American women and no studies that included African Americans evaluated whether associations differ by estrogen receptor (ER) status.

Methods: To assess the relation of aspirin use to risk of ER+ and ER- breast cancer in African American women, we conducted a prospective analysis within the Black Women's Health Study, an ongoing nationwide cohort of 59,000 black women that began in 1995. On baseline and biennial follow-up questionnaires, women reported regular aspirin use (defined as use at least three days per week) and years of use. Acetaminophen use was queried similarly. Among women with available information on aspirin use, 1701 invasive breast cancers occurred during follow-up through 2015, including 962 ER+ and 492 ER- tumors. All cancers were confirmed through pathology reports or state cancer registry data. We used age-stratified Cox proportional hazards regression models to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of aspirin use with risk of ER+ and ER- breast cancer. All models adjusted for age at menarche, oral contraceptive use, parity, age at first birth, estrogen plus progestin use, body mass index, alcohol consumption, and use of other NSAIDs.

Results: Compared to never use, current regular use of aspirin was associated with lower risk of breast cancer overall (HR 0.87; 95% CI 0.76, 1.00). The association was driven by a statistically significant inverse association for ER- breast cancer (HR 0.76; 95% CI 0.58, 0.99); for ER+ breast cancer, the corresponding HR was 0.92 (95% CI 0.77, 1.09). In contrast, we found no associations with acetaminophen use.

Conclusions: Our observation of reduced risk of ER- breast cancer in relation to current regular use of aspirin is consistent with anti-inflammatory effects of aspirin, rather than hormone-dependent pathways. Aspirin may represent a potential opportunity for chemoprevention of ER- breast cancer; however, these findings require corroboration in additional studies.

Citation Format: Kimberly A. Bertrand, Traci N. Bethea, Hanna Gerlovin, Patricia Coogan, Lucile L. Adams-Campbell, Lynn Rosenberg, Julie R. Palmer. Aspirin use and estrogen receptor-negative breast cancer risk in African American women [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 5247.
Abstract 5253: Dietary fiber intake and lung cancer risk: A pooled analysis of 1.44 million individuals in 10 cohorts
Authors: Yang Jae Jeong , Yu Danxia , Xiang Yong-Bing , Blot William , Robien Kim , Sinha Rashmi , Park Yikyung , White Emily , Takata Yumie , Johansson Mattias , Zheng Wei , Shu Xiao-Ou
Published: August 2018

Background: Dietary fiber has been shown to have various health benefits, including anti-inflammation. However, the role of dietary fiber on lung cancer risk has not been well characterized. In this pooled analysis of 10 prospective cohort studies from the US, Europe, and Asia, we evaluated the association between dietary fiber intake and risk of lung cancer and further, potential effect modifications by tobacco smoking, alcohol drinking, and demographic factors (e.g., sex and race/ethnicity).

Methods: Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated within each cohort using Cox proportional hazard models with adjustment for major lung cancer risk factors. Risk estimates from each cohort were pooled using random-effects meta-analysis. To reduce potential reverse causation due to preclinical dietary changes, all analyses were conducted excluding the first two years of observation.

Results: A total of 18,822 incident lung cancer cases were identified among 1,445,850 participants during mean follow-ups of 9.4 years. After adjustment for lung cancer risk factors (i.e., age, total energy, smoking status, smoking pack-years, gender, race/ethnicity, education, obesity status, diabetes, family history of lung cancer, alcohol consumption, physical activity level, menopausal status in women, and intake of saturated and polyunsaturated fat), dietary fiber intake was inversely associated with lung cancer risk (HR [95% CI] = 0.90 [0.83-0.99] for highest vs. lowest quintile and 0.93 [0.89-0.97] per 10g/day increase). Stratified analyses showed a significant inverse association in men (HRs [95% CIs] per 10g/day increase = 0.92 [0.85-1.00]), women (0.94 [0.90-0.99]), whites (0.92 [0.88-0.95]), smokers (0.92 [0.88-0.97]), and alcohol drinkers (0.89 [0.86-0.94]). However, no significant association was found in Blacks (1.05 [0.92-1.19]), Asians (0.99 [0.85-1.16]), never smokers (0.97 [0.88-1.07]), and never drinkers (0.99 [0.94-1.05]) (P interaction = 0.06 for sex, 0.004 for race, 0.17 for tobacco smoking, and <0.001 for alcohol drinking).

Conclusion: Our findings suggest that a high-fiber diet was associated with a lower risk of lung cancer among whites, smokers, and alcohol drinkers. Further research is needed to determine if the association between dietary fiber intake and lung cancer risk reflects a causal relation.

Citation Format: Jae Jeong Yang, Danxia Yu, Yong-Bing Xiang, William Blot, Kim Robien, Rashmi Sinha, Yikyung Park, Emily White, Yumie Takata, Mattias Johansson, Wei Zheng, Xiao-Ou Shu. Dietary fiber intake and lung cancer risk: A pooled analysis of 1.44 million individuals in 10 cohorts [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 5253.
Abstract 5260: Alcohol consumption and risk of gastric cardia adenocarcinoma and gastric non-cardia adenocarcinoma: A prospective analysis from the NIH-AARP Diet and Health cohort
Authors: Wang ShaoMing , Freedman Neal D. , Loftfield Erikka , Hua Xing , Abnet Christian C.
Published: August 2018

Objective: The 2016 WCRF Continuous Update Project reported that consumption of alcoholic drinks probably causes gastric cancer, but the magnitude of the association was small, there was moderate heterogeneity among the studies included in the meta-analysis, and most studies were from Asian populations, with only 401 cases from North American studies. Therefore, we re-evaluated the association between alcohol intake and gastric cancer in a large US cohort that has accrued more than 1300 gastric cancer cases.

Methods: We prospectively investigated the associations of alcohol consumption with gastric cardia adenocarcinoma (GCA) and gastric non-cardia adenocarcinoma (GNCA) in 490,605 members aged 50-71 years at baseline in the NIH-AARP Diet and Health Study cohort. Alcohol consumption was assessed during the baseline questionnaire in 1995/1996 and evaluated as grams of ethanol intake and as a categorical variable: never, up to or including one drink/day, one to three drinks/day, and greater than three drinks/day. We used Cox proportional hazard regression to calculate the hazard ratios and 95% confidence intervals for associations between alcohol intake and risk of gastric adenocarcinomas with adjustment for several potential confounders.

Results: Through 2011, 662 incident cases of GCA and 713 of GNCA occurred in the cohort. We found no association between higher alcohol consumption and GCA or GNCA, regardless of whether analyzed as total alcoholic beverage intake or the individual beverage types of beer, wine and liquor and no evidence for a dose-response. Furthermore, we observed no association by stratum of sex, ethnic group, educational level, or smoking status. Although there were no overall associations, we found some evidence for lower risk of GNCA among people who drank up to one drink per day (HR=0.81, 95%CIs:0.67-0.97) compared to nondrinkers.

Conclusion: Alcohol consumption was not associated with increased risk of gastric cardia adenocarcinoma or gastric non-cardia adenocarcinoma in this large US prospective cohort.

Citation Format: ShaoMing Wang, Neal D. Freedman, Erikka Loftfield, Xing Hua, Christian C. Abnet. Alcohol consumption and risk of gastric cardia adenocarcinoma and gastric non-cardia adenocarcinoma: A prospective analysis from the NIH-AARP Diet and Health cohort [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 5260.
Abstract 5270: Associations of circulating 25-hydroxyvitamin D3 concentrations with incident, sporadic colorectal adenoma risk according to common vitamin D-binding protein isoforms
Authors: Gibbs David C.
Published: August 2018

25-hydroxyvitamin D3 (25[OH]D3), the main circulating form of vitamin D, is inversely associated with incident, sporadic colorectal adenoma. We investigated whether this association differs by two functional variants in the vitamin D binding protein gene (GC) that encode for common protein isoforms (Gc1s, Gc1f, Gc2) linked to differences in vitamin D metabolism. We pooled data from three US colonoscopy-based case-control studies (418 adenoma cases, 524 polyp-free controls), and estimated 25(OH)D3-adenoma associations, by GC isoforms, using multivariable logistic regression. Consistent with previous studies, mean-adjusted 25(OH)D3 concentrations were lowest among Gc2 homozygotes (20.7 ng/mL, 95% CI: 26.2, 28.0) and highest among Gc1 (combined Gc1s and Gc1f) homozygotes (27.1 ng/mL, 95% CI: 18.6, 22.7). Higher 25(OH)D3 concentrations were inversely associated with colorectal adenoma among those with the Gc2 isoform (per 10 ng/mL increase in 25(OH)D3 odds ratio = 0.71; 95% confidence interval: 0.56, 0.90), but not among those with only Gc1 isoforms (odds ratio = 1.07; 95% confidence interval: 0.87, 1.32) (Pinteraction = 0.03). These novel findings suggest that the vitamin D-incident, sporadic colorectal adenoma association may differ by common GC isoforms, and that those with the Gc2 isoform may particularly benefit from maintaining higher circulating 25(OH)D3 concentrations for adenoma prevention.

Citation Format: David C. Gibbs. Associations of circulating 25-hydroxyvitamin D3 concentrations with incident, sporadic colorectal adenoma risk according to common vitamin D-binding protein isoforms [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 5270.
Abstract 5275: Comparing self-reported cognitive function among Caucasian and African American breast cancer survivors
Authors: Lewis Kayla A. , Vo Jacqueline B. , Royston Kendra J. , Gisiger-Camata Silvia , Meneses Karen
Published: August 2018

Approximately 35% of breast cancer survivors (BCS) report changes in cognitive function after cancer treatment. The purpose of this abstract is to compare self-reported cognitive changes between Caucasian (CAU) and African American (AA) BCS who participated in the Think Well program.

Think Well is an educational program to increase awareness of cognitive function and promote healthy living. Sixteen Think Well seminars were delivered in-person to urban and rural counties throughout North Central Alabama. Following each seminar, participants completed an evaluation of demographic information and cognitive changes. Descriptive statistics and chi-squared tests were used. Data were analyzed using SPSS v23.

Among BCS who completed the evaluation, 82 (54%) were CAU, and 62 (41%) were AA. Many BCS were employed (32%) or disabled/retired (51%). CAU were more likely to be married than AA BCS (p<0.01). More CAU self-reported “poor/below average” in domains of memory, ability to think, speed of problem solving, and ability to pay attention than AA BCS (p<0.01). CAU were more likely than AA BCS to report “moderately” or “very much/extremely” in changes in ability to think (p<0.01), speed of problem solving (p=0.02), and ability to pay attention (p=0.01) since completion of breast cancer treatment.

CAU BCS self-reported poorer cognitive function and changes since cancer treatment. Differences in self-reported changes between AA and CAU may be contributed to geographic location, racial differences in perception of cognitive function, or marital status. Race-related stigmas may affect self-reporting of cognitive function. Future research is warranted to examine factors that contribute to racial differences in cognitive function and interventions aimed at improving cognitive function among both AA and CAU BCS.

Acknowledgement: Think Well is supported by a grant from the North Central Alabama Affiliate of Susan G. Komen. Authors are also supported by funding: Susan G. Komen Graduate Traineeship in Disparities Research, Robert Wood Johnson Foundation Future of Nursing Scholarship, and American Cancer Society Doctoral Degree Scholarship in Cancer Nursing (DSCN-17-076-01).

Citation Format: Kayla A. Lewis, Jacqueline B. Vo, Kendra J. Royston, Silvia Gisiger-Camata, Karen Meneses. Comparing self-reported cognitive function among Caucasian and African American breast cancer survivors [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 5275.
Abstract 528: Identification of MYC as a novel repressor of miR-29 in pancreatic ductal adenocarcinoma
Authors: Kwon Jason , Quirin Kayla , Factora Tricia , Kota Janaiah
Published: August 2018

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant disease with a dismal 5-year survival rate of 8%. The lack of effective therapies reinforces the need to better understand molecular mechanisms in PDAC. In our previous work, we found that downregulation of miR-29 is a common phenomenon of PDAC, and its restored expression had a potent tumor-suppressive effect in pancreatic cancer cells. However, the mechanism associated with the loss of miR-29 in PDAC has yet to be elucidated. In our initial work, using PDAC cell lines, we found that miR-29 is downregulated independent of KRAS. In an effort to understand the transcriptional factors mediating miR-29 repression, we selected several transcription factors that have a role in PDAC pathogenesis and binding sites in the miR-29 promoter region. siRNA mediated knockdown (KD) of three candidate transcription factors, SMAD4, MYC, and Gli3 revealed that the KD of MYC resulted in the highest gain of miR-29 expression (2-fold increase). Furthermore, MYC nuclear localization negatively correlates with miR-29 expression in various pancreatic cancer cell lines, and treatment of pancreatic cancer cells with small-molecule MYC inhibitor resulted in a dosage-dependent increase of miR-29 expression. miR-29a/b1 locus located on human chromosome 7 has two canonical MYC binding motifs upstream of the miR-29 transcription start site, which were functionally validated via luciferase assay. Finally, autophagy has been shown to be upregulated by MYC and is known to mitigate stressors of the integrated stress response (ISR) pathway in cancer. In our previous work, we showed that miR-29 blocks autophagy in pancreatic cancer cells. Consistently, we found miR-29 overexpression led to decreased cancer cell viability in combination with gemcitabine and induced the ISR as indicated by increased phospho-eIF2α. Taken together, our results demonstrate that MYC plays a key role in the regulation of miR-29 expression in pancreatic cancer. Furthermore, our data indicate the potential use of miR-29 as a novel therapeutic agent for PDAC, and these results could help form the basis for future studies to develop a more targeted approach of miR-29 therapeutic administration.

Citation Format: Jason Kwon, Kayla Quirin, Tricia Factora, Janaiah Kota. Identification of MYC as a novel repressor of miR-29 in pancreatic ductal adenocarcinoma [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 528.
Abstract 531: Heterozygous IDH1
R132H/WT created by “single base editing” inhibits human astroglial cell growth by downregulating YAP
Authors: Wei Shuang , Wang Jie , Oyinlade Olutobi , Ma Ding Ma , Wang Shuyan , Xia Shuli
Published: August 2018

Mutations in the isocitrate dehydrogenase 1 (IDH1) gene have been identified in a number of cancer types, including brain cancer. The Cancer Genome Atlas project has revealed that IDH1 mutations occur in 70-80% of grade II and grade III gliomas. Until recently, most of the functional studies of IDH1 mutations in cellular models have been conducted in overexpression systems with the IDH1 wild type background. In this study, we employed a modified CRISPR/Cas9 genome editing technique called “single base editing”, and efficiently introduced heterozygous IDH1 R132H mutation in human astroglial cells (~20%). Compared with astroglial cells with IDH1 wild type, monoallelic IDH1 R132H mutation (IDH1R132H/WT) inhibited cell proliferation and promoted cell migration. Global gene expression analysis identified molecular targets and pathways altered by IDH1R132H/WT, including cell proliferation, extracellular matrix, and cell migration, consistent with our phenotype characterization. Global DNA methylation profiling showed hypermethylation as well as hypomethylation induced by IDH1R132H/WT. Using our mutated IDH1 models generated by genome editing, we identified novel molecular targets of IDH1R132H/WT, namely Yes-associated protein (YAP) and its downstream signaling pathway Notch, to mediate the cell growth-inhibiting effect of IDH1R132H/WT. Our findings are in line with the clinical observations that brain tumor patients with mutated IDH1 have a better prognosis. In summary, the “single base editing” strategy has successfully created heterozygous IDH1 R132H mutation that recapitulate the naturally occurring IDH1 mutant. Our isogenic cellular systems that differ in a single nucleotide in one allele of the IDH1 gene provide a valuable model for novel discoveries of IDH1R132H/WT-driven biological events.

Citation Format: Shuang Wei, Jie Wang, Olutobi Oyinlade, Ding Ma Ma, Shuyan Wang, Shuli Xia. Heterozygous IDH1R132H/WT created by “single base editing” inhibits human astroglial cell growth by downregulating YAP [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 531.
Abstract 532: PELP1 and AIB1 (SRC-3) complexes promote cancer stem cell-associated phenotypes in ER+ breast cancer models
Authors: Truong Thu H. , Hu Hsiangyu , Temiz Nuri A. , Hagen Kyla M. , Girard Brian J. , Brady Nicholas J. , Schwertfeger Kathryn L. , Lange Carol A. , Ostrander Julie H.
Published: August 2018

Proline, glutamic acid, and leucine rich protein 1 (PELP1) is overexpressed in approximately 80% of invasive breast tumors. PELP1 dynamically shuttles between the nucleus and cytoplasm, but is primarily nuclear in normal breast tissue. However, altered localization of PELP1 to the cytoplasm is an oncogenic event that promotes breast cancer initiation and progression. Herein, we sought to identify interacting partners unique to cytoplasmic PELP1 and determine the mechanisms by which these interactions promote oncogenic PELP1 signaling. We identified AIB1 (amplified in breast cancer 1; also known as SRC-3 or NCOA3) as a novel binding partner of cytoplasmic PELP1 in both estrogen receptor-positive (ER+) and ER-negative cell lines. Cytoplasmic PELP1 expression elevated basal phosphorylation levels (i.e., activation) of AIB1, enhanced ALDH+ tumorsphere formation, and upregulated specific target genes independently of hormone stimulation. Direct manipulation of AIB1 levels using shRNA abrogated cytoplasmic PELP1-induced tumorsphere formation and downregulated cytoplasmic PELP1-specific target genes. SI-2, an AIB1 inhibitor, inhibited the PELP1/AIB1 interaction and decreased cytoplasmic PELP1-induced tumorsphere formation. Similar results were observed in a murine-derived MMTV-AIB1 tumor cell line (J110). Furthermore, in vivo syngeneic tumor studies showed that PELP1 knockdown in J110 cells resulted in increased survival of tumor-bearing mice as compared to mice injected with control cells. These studies suggest that manipulating PELP1 location or levels has the potential to mitigate tumor progression, particularly in the context of AIB1-mediated tumorigenesis. Taken together, our data demonstrate that cytoplasmic PELP1/AIB1-containing complexes function to promote advanced cancer phenotypes, including outgrowth of stem-like cells, associated with estrogen-independent breast cancer progression.

Citation Format: Thu H. Truong, Hsiangyu Hu, Nuri A. Temiz, Kyla M. Hagen, Brian J. Girard, Nicholas J. Brady, Kathryn L. Schwertfeger, Carol A. Lange, Julie H. Ostrander. PELP1 and AIB1 (SRC-3) complexes promote cancer stem cell-associated phenotypes in ER+ breast cancer models [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 532.
Abstract 5326: Differential methylation observed in cancer related genes between DNA samples from normal and obese individuals
Authors: Drennan Ryan , Culhane Nicolas , Poulin Matthew L. , Liu Zhenhua , Yan Liying
Published: August 2018

Based on research funded by The American Institute for Cancer Research, evidence is clear that weight can affect your risk of developing cancer. It is estimated that close to 1/3 of cancers that occur every year in the U.S. could be prevented by maintaining a healthy weight, being physically active and eating a nutritious diet. The body mass index (BMI) is defined as the body mass divided by the square of the body height and is typically expressed in kg/m2. BMI between 18.5 and 25 are considered normal while BMI of 25 to 30 is overweight and greater than 30 is considered obese. We have analyzed the DNA methylation levels of 18 individuals with BMI >30, and compared them to 7 individuals with BMI between 18.5 and 25 utilizing three targeted Next-Gen Bisulfite Sequencing (tNGBS) panels that we have developed as well as with individual pyrosequencing assays. The three panels, FOXP3, Immunology and Cancer Panels, cover regulatory regions of 44 genes that include over 400 CpG sites in addition to a global methylation assay to the LINE1 promoter. The results show that seven gene regulatory regions and the LINE1 global methylation assay show significant differential methylation between the obese and the normal BMI samples. ESR1, PAPR1, EN1, LXH2, TFF1, FOXP3 and LINE1 were shown to be hypermethylated and CD3G was hypomethylated, with p-values ranging between 0.08 and 0.005. Larger sample cohorts can now be examined more thoroughly with individual pyrosequencing assays to further validate the findings.

Citation Format: Ryan Drennan, Nicolas Culhane, Matthew L. Poulin, Zhenhua Liu, Liying Yan. Differential methylation observed in cancer related genes between DNA samples from normal and obese individuals [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 5326.
Abstract 5328: Intergenic DNA methylation differences in ER- breast tumors from African American versus European American women
Authors: Buas Matthew F. , Chen Jianhong , Hu Qiang , Liu Song , Gong Zhihong , Higgins Michael J. , Ambrosone Christine B.
Published: August 2018

Incidence of estrogen receptor (ER)-negative breast cancer, a subtype with worse prognosis, is higher among African American (AA) versus European American (EA) women. The reasons for this gap remain poorly defined, but likely include differences in the prevalence and biological effects of known risk factors for ER- disease (eg. parity without breastfeeding and early menarche). These exposures may influence risk of ER- cancer via multiple mechanisms, one of which is epigenetic regulation of gene expression. Altered expression of genes controlling the proliferation and/or differentiation of luminal progenitor cells in the breast is likely to affect the propensity of such cells to give rise to ER- versus ER+ cancer. We previously conducted genome-wide DNA methylation profiling of 224 ER- tumor samples from 141 AA and 83 EA women in the Women's Circle of Health Study, and identified 374 differentially methylated loci (DML) by race. Our initial analysis focused on DMLs mapping to annotated genes, and revealed that a key pro-luminal transcription factor gene, FOXA1, was hypermethylated and repressed in AA compared to EA tumors. Moreover, parity without breastfeeding, more common among AAs, was associated with increased FOXA1 methylation. In this study, motivated by the biological importance of the non-coding genome, we focused on ~100 intergenic DML, and used paired 450K and RNA-seq data to assess the relationship between CpG methylation and RNA expression of genes located up to 50 kb away. Methylation at ten DML was significantly correlated with paired gene expression (FDR q<0.05). For seven of these loci, lower methylation tracked with higher expression of the paired gene. One such CpG, hypomethylated in AA versus EA tumors, mapped to a putative enhancer element located 19 kb upstream of, and predicted to interact with, the promoter of LEMD1, a pro-tumorigenic cancer-testis antigen. Analysis of an independent set of 207 ER- breast cancers from TCGA confirmed that LEMD1 RNA expression was higher in AA compared to EA tumors (P=0.01, log2FC=0.95). Our findings suggest that epigenetic differences between AA and EA ER- tumors are linked to altered gene expression and may hold functional significance in breast cancer pathogenesis. Further studies are needed to extend these results to normal breast tissues from cancer-free women, and explore a potential role for FOXA1/LEMD1 epigenetic regulation in luminal progenitor cell homeostasis.

Citation Format: Matthew F. Buas, Jianhong Chen, Qiang Hu, Song Liu, Zhihong Gong, Michael J. Higgins, Christine B. Ambrosone. Intergenic DNA methylation differences in ER- breast tumors from African American versus European American women [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 5328.
Abstract 533: OTULIN promotes resistance and metastasis upon chemotherapy in TNBC by activating Wnt/β-Catenin signaling
Authors: Wang Wei , Niu Jixiao , Zhang Bo , Wu Zhaohui
Published: August 2018

Triple-negative breast cancer (TNBC) or Basal-like breast cancer is characterized by worse prognosis than other breast cancer subtypes due to the rapid-arising therapeutic resistance accompanied by aggressive metastasis. The therapy-resistant tumor cells, including cancer stem-like cells (CSCs) with intrinsic resistance or tumor cells acquired resistance during treatments, could repopulate the primary tumors and serve as seeds for recurrent metastatic lesions. However, the molecular events orchestrating the innate and acquired therapeutic resistance are not completely understood. We found that the linear ubiquitin-specific deubiquitinase OTULIN is overexpressed in breast tumors, especially in the basal-like subtype, compared with normal breast tissues. Moreover, OTULIN overexpression significantly increased TNBC cells resistance to chemotherapy and is associated with shorter DFS in breast cancer patients. Mechanistically, we found genotoxic treatments activate OTLULIN, which promotes epithelial-to-mesenchymal transition (EMT) in TNBC cells through increased activity of Wnt/β-Catenin signaling. OTULIN overexpression significantly enhanced TNBC cells resistance to chemodrugs while inhibiting Wnt/β-Catenin signaling or OTULIN sensitized TNBC xenografts to Doxorubicin treatment in vivo. Our findings suggest that OTULIN-mediated Wnt/β-Catenin activation may increase TNBC therapeutic resistance and aggressiveness by promoting EMT. Targeting OTULIN and the chemotherapy-induced Wnt/β-Catenin activation may serves as promising strategy to mitigate drug resistance and reduce metastasis in TNBC patients receiving chemotherapy.

Citation Format: Wei Wang, Jixiao Niu, Bo Zhang, Zhaohui Wu. OTULIN promotes resistance and metastasis upon chemotherapy in TNBC by activating Wnt/β-Catenin 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 533.
Abstract 5330: DNA hypomethylation promotes carcinogenesis by inducing cryptic transcription
Authors: Lou Dan , Li Yanqiang , Martos Suzanne M. , Zhu Yan , Freeman Dana , Wang Zhibin
Published: August 2018

DNA methylation, regulate genomic processes and serve at the interface between genes and the environment, has long been recognized as the key event involved in cancer initiation and development. However, how exactly the role of DNA methylation and their epigenomic consequences underlying carcinogenesis remains to be elucidated. We previously reported that a division of labor between DNA methyltransferase (DNMT) (DNMT1 and DNMT3a/3b) to suppress distinct types of genome components. Additionally, allelic and biomodal methylation patterns have been revealed by using two bioinformatics methods. To determine how the DNA methylation affects the integrity of gene transcription, we applied the appropriate PRO-cap technique that detects 5'-capped RNA transcripts in wildtype (WT) mESCs and three mutant mESCs with altered DNMT: loss of DNMT1 (DNMT1-/- ; 1KO), loss of DNMT3a/3b (DNMT3a-/-/DNMT3b-/-; DKO) and loss of DNMT1 and DNMT3a/3b (DNMT1-/-/ DNMT3a-/-/DNMT3b-/-; TKO). With high quality of sequencing reads at high fold coverage and 150 millions of mapped reads for WT and mutant cells, our analyses revealed significant RNA transcripts alterations. By mapping global transcription start site (TSS) and chromatin dynamics, cryptic transcription of thousands of DNMT loss-induced non-annotated TSSs were observed. Some of the non-annotated TSSs were further confirmed in arsenic-treated malignant transformated cell line. Our results indicated that the alteration (completely loss or partially loss) of DNA methylation may promote the carcinogenesis by sabotaging the fidelity of gene transcription initiation.

Citation Format: Dan Lou, Yanqiang Li, Suzanne M. Martos, Yan Zhu, Dana Freeman, Zhibin Wang. DNA hypomethylation promotes carcinogenesis by inducing cryptic transcription [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 5330.
Abstract 5331: Repression of TET genes and enhancement of DNA methyltransferase activity are critical for induction of aberrant DNA methylation
Authors: Takeshima Hideyuki , Niwa Tohru , Yamada Harumi , Yamashita Satoshi , Wakabayashi Mika , Ushijima Toshikazu
Published: August 2018

Chronic inflammation is deeply involved in the development of human cancers by inducing epigenetic alterations, such as aberrant DNA methylation. Among various inflammatory cytokines, the expression of Il1b, Tnf, and Nos2, is associated with induction of aberrant DNA methylation. However, the molecular mechanisms by which these cytokines induce aberrant DNA methylation remain unclear. Here, we show that the activation of the NF-kB signaling pathway, downstream of IL-1β and TNF-α, caused up-regulation of specific miRNAs, such as miR-20a, miR-26b, and miR-29c, and that these miRNAs caused repression of the Tet methylcytosine dioxygenases (Tet) genes, Tet1, Tet2, and Tet3. TET repression by overexpression of one of these miRNAs in cultured cells appeared to be insufficient for induction of aberrant DNA methylation as detected by an Infinium MethylationEPIC BeadChip array. However, triple knockout of TET genes induced strong DNA methylation at thousands of genomic loci. At the same time, exposure to nitric oxide, produced by Nos2, enhanced enzymatic activity of DNA methyltransferases (DNMTs). Treatment of cultured cells with nitric oxide induced weak DNA methylation at hundreds of genomic loci. These results show that both the repression of TET genes and enhancement of DNMT activity, induced by chronic inflammation, are critical for induction of aberrant DNA methylation. ''Vicious'' combination of such dysregulations might have a synergistic effect on induction of aberrant DNA methylation.

Citation Format: Hideyuki Takeshima, Tohru Niwa, Harumi Yamada, Satoshi Yamashita, Mika Wakabayashi, Toshikazu Ushijima. Repression of TET genes and enhancement of DNA methyltransferase activity are critical for induction of aberrant DNA methylation [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 5331.
Abstract 5334: Spg20 (Spartin) promoter methylation identifies tumor B lymphocytes
Authors: Frazzi Raffaele , Simone Tonia De , Pistoni Mariaelena , Merli Francesco
Published: August 2018

Introductory sentence. The layer of regulation represented by gene promoter methylation is being investigated in Non-Hodgkin lymphoma (NHL) cell lines, primary B lymphocytes and peripheral blood mononuclear cells (PBMCs). The aim is to assess whether the panel of differentially methylated genes we previously identified is able to distinguish normal B lymphocytes from lymphoma cells.

Experimental procedures. Quantitative, gene-specific methylation assays. Immunosorting of human B lymphocytes. Proliferation assays. 5-azacytidine treatment. NHL-derived cell lines.

New data. Here we show that NHL-derived cell lines display a characteristic profile of promoter methylation on specific tumor suppressors and target genes. A panel of 9 target promoters was selected previously and assessed on a series of healthy and tumor primary B lymphocytes. 4 out of 5 NHL-cell lines show a highly methylated profile on KLF4, DAPK1 and SPG20, at variance with normal B lymphocytes (lymph-node derived) and PBMCs where these targets are completely unmethylated. Interestingly, PBMCs from healthy donors display the same methylation pattern as the one shown by B lymphocytes immunologically sorted from follicular hyperplasias. Spartin (SPG20) emerges here as a differentially methylated gene associated to lymphocyte malignancy, at variance with other tumor suppressors in our panel that show variability among different cell lines. SPG20 is completely or highly methylated in all the tested NHL-cell lines. According to this observation, SPG20 results not methylated in PBMCs as well as sorted non-tumor B lymphocytes. On the contrary, the methylation status of three different BCL6 CpG islands (assessed with the same technique) may vary among different cell lines. In order to investigate what's the functional role of these specific promoters methylation, we treated Toledo and NU-DUL-1 cell lines with the demethylating agent 5-azacytidine (5AZA). We observe that the dose-dependent inhibition of proliferation upon 5AZA is accompanied by a small but reproducible decrease in SPG20 and MZB1 promoter methylation. Experiments aimed at assessing any involvement of DNA methyltransferases DNMT1 and DNMT3a are currently ongoing.

Conclusions. Our data show a consistent methylation profile of 9 gene promoters on 5 different NHL-derived cell lines. Spartin emerges as a completely methylated promoter in the tested tumor cells. PBMCs show a consistent unmethylated profile of Spartin and of all the target genes. The epigenetic regulation of these genes in B-derived lymphomas warrants further investigation.

Citation Format: Raffaele Frazzi, Tonia De Simone, Mariaelena Pistoni, Francesco Merli. Spg20 (Spartin) promoter methylation identifies tumor B lymphocytes [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 5334.
Abstract 5335: A highly efficient targeted bisulfite sequencing method for accurate DNA methylation profiling
Authors: Peng Quan , Kim Daniel , Ranjbar Mohammad Nezami , Strauss Sascha , Winter Scott , Wang Yexun
Published: August 2018

Background DNA methylation plays an important role in gene regulation. Bisulfite sequencing (BS), in which unmethylated cytosines are converted to uracil while methylated cytosines remain intact, is considered as the gold standard for DNA methylation detection with single nucleotide resolution. Due to the high cost of whole genome BS and the low throughput of amplicon BS, there remains the need for new targeted bisulfite sequencing methods with high efficiency and flexibility.

Results We developed a targeted bisulfite sequencing method, by incorporating single primer enrichment (SPE) and molecular barcoding (UMI) technology. This enables flexible and scalable targeted DNA methylation analysis with high efficiency. We first studied the ability of our assay to detect CpG methylation at various levels in reference materials. We also evaluated its utility in profiling CpG methylation in different cell line DNA, and compared the results with published data from alternative technologies (WBS, RRBS and microarray).

Conclusions We demonstrated the successful implementation of SPE and UMI technology on bisulfite converted DNA with high enrichment specificity and low bias. We showed that our method accurately detected CpG methylation at different levels, in concordance with expected titration mixture or published datasets. Comparing to reported amplicon BS, our technology enables much higher multiplexing scale and much simpler workflow. Comparing to probe capture based enrichment, our technology enables much lower DNA input, much higher sequencing efficiency (on-target) and shorter turnaround time.

Citation Format: Quan Peng, Daniel Kim, Mohammad Nezami Ranjbar, Sascha Strauss, Scott Winter, Yexun Wang. A highly efficient targeted bisulfite sequencing method for accurate DNA methylation profiling [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 5335.
Abstract 5339: Epigenetic silencing of ANGPTL4 in tumor tissues and its overexpression in the urothelial carcinoma microenvironment
Authors: Chan Michael WY , Hsieh Hsiao-Yen , Jou Yeong-Chin , Tung Chun-Liang , Tsai Yuh-Shyan , Wang Yuan-Hung , Chi Chen-Lin , Lin Ru-Inn , Hung Shih-Kai , Chuang Yu-Ming , Wu Shu-Fen , Li Chin , Shen Cheng-Huang , Hsu Cheng-Da
Published: August 2018

Urothelial carcinoma (UC) carcinogenesis has been hypothesized to occur through epigenetic repression of tumor suppressor genes (TSGs). By qRT-PCR array, we found that one potential TSG, ANGPTL4, was expressed at very low levels in all UC cell lines we examined. Previous studies had demonstrated that ANGPTL4 is highly expressed in some cancers, but downregulated, by DNA methylation, in others. Consequently, due to these seemingly conflicting functions in distinct cancers, the precise role of ANGPTL4 in the etiology of UC remains unclear. In this study, using methylation-specific PCR and bisulfite pyrosequencing, we show that ANGPTL4 is transcriptionally repressed by promoter hypermethylation in UC cell lines and primary tumor samples, as compared to adjacent noncancerous bladder urothelium. Functional studies further demonstrated that ectopic expression of ANGPTL4 potently suppressed UC cell proliferation, monolayer colony formation in vitro, and invasion, migration, and xenograft formation in vivo. As ANGPTL4 is a secreted factor, we therefore examined the circulating ANGPTL4 (cir-ANGPTL4) level in UC patients. Surprisingly, cir-ANGPTL4 was significantly higher in plasma samples from UC patients than normal control, suggesting it might be secreted from other cell types. More importantly, exogenous c-terminal fragment of ANGPTL4 (cANGPTL4) could promote cell proliferation and cell migration via activation of signaling through the Erk/FAK axis. We further confirmed that mouse xenograft tumor growth could be promoted by administration of exogenous cANGPTL4. Finally, immunohistochemistry demonstrated that ANGPTL4 was downregulated in tumor cells but overexpressed in tumor-adjacent stromal tissues including muscle and macrophages of muscle-invasive UC tissue samples. In conclusion, our data supports dual roles for ANGPTL4 in urothelial carcinoma progression, either as a tumor suppressor or oncogene, in response to microenvironmental context.

Citation Format: Michael WY Chan, Hsiao-Yen Hsieh, Yeong-Chin Jou, Chun-Liang Tung, Yuh-Shyan Tsai, Yuan-Hung Wang, Chen-Lin Chi, Ru-Inn Lin, Shih-Kai Hung, Yu-Ming Chuang, Shu-Fen Wu, Chin Li, Cheng-Huang Shen, Cheng-Da Hsu. Epigenetic silencing of ANGPTL4 in tumor tissues and its overexpression in the urothelial carcinoma microenvironment [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 5339.