bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B96: Tackling obesity-related cancer health disparity, new inhibitors of leptin signaling
Authors: Lipsey Crystal C. , Harbuzariu Adriana , Dill Courtney , Gonzalez-Perez Ruben R.
Published: May 2016

Obesity is a global pandemic that has been linked to the progression of several different cancers including: breast, pancreatic, and endometrial. The presence of excessive amounts of adipose tissue leads to increased production and circulation of leptin, a 16kDa protein adipokine. Leptin mediates several signaling pathways that are essential to angiogenesis, proliferation, migration, and cancer cell survival. Chronically high levels of circulating leptin have been shown to increase proliferation of cancer cells. Obese African American patients suffering from triple negative breast TNBC or pancreatic cancer have worse clinical outcomes than Caucasian women. Leptin could be a survival factor for these cancers, which lack specific therapies and are treated with chemotherapeutic drugs, which show several undesirable effects. Moreover, these cancers show notable development of chemoresistance and recurrence. We have designed and tested a potent leptin antagonist LPrA2 that inhibits leptin-induced proliferation, invasion, and migration of several cancer cell types. Recently, new LPrA2- like antagonists have been produced. We hypothesize that the new peptide antagonists could be more effective inhibitors of leptin signaling when treating cancer cells in comparison to LPrA2. LPrA2-like antagonists showed no toxicity in non-malignant cells. Minimally invasive and a highly metastatic TNBC and pancreatic cell lines were treated with leptin and antagonists for 24 and 48 hours. Cellometer analysis and MTT assay were used to determine cell cycle staging and cell proliferation, respectively. Additionally, apoptosis rate was determined after combinatory treatments with leptin antagonists and chemotherapeutics were applied to the cancer cells. Our results show that LPrA2-like antagonists were more effective inhibitors of leptin induced S-phase, proliferation and survival than LPrA2. Results from this investigation could lead to the development of new therapeutic regimens for obesity-related cancers, which could help eliminating the gap of cancer health disparity in African American patients.

Citation Format: Crystal C. Lipsey, Adriana Harbuzariu, Courtney Dill, Ruben R. Gonzalez-Perez. Tackling obesity-related cancer health disparity, new inhibitors of leptin signaling. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B96.
Abstract C15: Using grounded theory to develop a model of prostate cancer care and survivorship for black men: The Florida CaPCaS study
Authors: Young Mary Ellen , Odedina Folakemi T. , Williams Christopher , Pereira Deidre , Dagne Getachew , Egensteiner Eva , Gilbert Lauren , Stokes Kenneth , Hill Christopher , Piervil Esther
Published: May 2016

The purpose of this study is to explore the experience of screening, diagnosis, treatment and survivorship of black men with prostate cancer using qualitative ground theory methodology. A sample of black men diagnosed with prostate cancer in 2010 was recruited via telephone screening from the Florida Department of Health cancer registry. The individuals recruited were purposively sampled for variation in country of origin (African, Caribbean, and US born) and other demographics. An open-ended interview guide about their prostate cancer experience, developed by our Community Advisory Board and revised by the scientific team, was used to conduct in-depth, face-to-face interviews of 2-3 hours in length. The interviews were scheduled at the convenience of the participant and conducted by a black male Community Health Worker in a private location in the community chosen by the participant. These steps were taken to assure maximum comfort for the participants to share their experiences fully. To date 14 interviews have been completed, with the goal of 60 interviews completed by the end of September, 2015. Data analysis consists of line-by-line coding of interview transcripts for themes that emerge from the interviews, followed by in-depth coding of constructs to be included in a grounded theory model of the prostate cancer experience for black men. Preliminary findings indicate emerging themes of trust of the health care providers, the impact of health literacy, views of active surveillance and watchful waiting, the importance of family support, and decisional regrets. Understanding the prostate cancer experience from the perspective of black prostate cancers survivors will help us to reduce the impact of the disease in this population.

Citation Format: Mary Ellen Young, Folakemi T. Odedina, Christopher Williams, Deidre Pereira, Getachew Dagne, Eva Egensteiner, Lauren Gilbert, Kenneth Stokes, Christopher Hill, Esther Piervil. Using grounded theory to develop a model of prostate cancer care and survivorship for black men: The Florida CaPCaS study. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C15.
Abstract C47: Gender and racial disparities in long-term survival of oral and oropharyngeal cancer in the United States
Authors: Osazuwa-Peters Nosayaba , Massa Sean T. , Christopher Kara M. , Walker Ronald J. , Varvares Mark A.
Published: May 2016

Purpose: Increased survivorship of head and neck cancer necessitates longer-term care for patients. However, no previous study from the United States has described head and neck survivorship beyond 15 years. The study aimed at describing 25-year survival of oral and oropharyngeal cancer; investigating the effect of race and gender on long-term survivorship.

Methods: The Surveillance, Epidemiology and End Results (SEER) database was queried for clinically and pathologically-defined adult oral and oropharyngeal cancer cases with at least 25 years follow-up. Kaplan-Meier survival curves were produced and a long-rank test was used to identify differences. A cox proportional hazards model was created including race, gender and other significant covariates.

Results: Of the 22,162 patients identified, 70.3% were males. Overall 10-year survival is 30.8% and survival declined through the follow up period, with only 8.9% alive at 25 years post-diagnosis. African American males show the poorest overall and disease specific survival rates (p<0.001). On multivariate analysis for cancer-specific survival, after controlling for age, marital status, cancer site, stage, treatment type, and socioeconomic status, African Americans had a 40% increase in the hazard of death compared to Caucasians (HR = 1.40, 95% CI = 1.35-1.46), while female gender was associated with a 9% reduction in mortality risk (HR=0.91, 95% CI = 0.88-0.94).

Conclusion: Overall survival for patients with oral and oropharyngeal cancer is poor with African Americans and males demonstrating the worst survival over both short and long term follow-up. This illustrates the need for a cancer survival plan that incorporates the role of disparities in overall cancer outcomes.

Citation Format: Nosayaba Osazuwa-Peters, Sean T. Massa, Kara M. Christopher, Ronald J. Walker, Mark A. Varvares. Gender and racial disparities in long-term survival of oral and oropharyngeal cancer in the United States. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C47.
Abstract C66: Adverse childhood experiences and breast cancer risk factors in black and white women
Authors: Warner Erica T. , Hargreaves Margaret K. , Mouton Charles P. , Tamimi Rulla M. , Signorello Lisa B.
Published: May 2016

Introduction: Adverse childhood experiences (ACE) have been implicated in several adult chronic diseases. ACE may also be associated with reproductive and lifestyle factors and biomarkers associated with breast cancer overall, and with estrogen receptor negative (ER-) disease specifically.

Methods: We examined whether self-reported ACE (verbal, physical, or sexual abuse; household mental illness or substance abuse; domestic violence, parental separation/divorce, and incarcerated household members) was associated with several reproductive and lifestyle breast cancer risk factors including age at menarche and age at first birth, and four biomarkers: adiponectin, C-peptide, high sensitivity C-reactive protein (hsCRP), and insulin-like growth factor-1 (IGF-1). The study population included 16,062 black and white women in the Southern Community Cohort Study. We grouped women into three categories: 0 experiences, 1-2 experiences and 3-10 experiences (high). Cross-sectional associations were analysed using logistic or linear regression.

Results: Women with high ACE were more likely to have: menarche before age 12, ever breastfed, more than two births, first birth before age 18, initiated smoking before age 16, and be current smokers compared to those with no ACE. Parous women with high ACE were 54% more likely to have ever breastfed (OR: 1.54, 95% CI: 1.39, 1.70; p-trend <0.0001) and 65% more likely to have first given birth before age 18 (OR: 1.65, 95% CI: 1.48, 1.85; p-trend <0.0001). ACE was not associated with body mass index (BMI) at enrollment, BMI at age 21, adiponectin, C-peptide or hsCRP levels. ACE was inversely associated with IGF-1. Women with high ACE had mean IGF-1 levels of 104.3 ng/ml compared to 119.2 ng/ml among women with no ACE (p-trend=0.007). Results generally did not differ between Blacks and Whites.

Conclusions: Our findings suggest that ACE is associated with reproductive patterns that have been shown to increase risk of ER- breast cancer. Future work should examine associations between ACE and breast cancer risk according to ER status.

Citation Format: Erica T. Warner, Margaret K. Hargreaves, Charles P. Mouton, Rulla M. Tamimi, Lisa B. Signorello. Adverse childhood experiences and breast cancer risk factors in black and white women. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C66.
Abstract C96: Community education; community advocacy
Authors: Currie Jacqueline Waldine
Published: May 2016

Community Education; community advocacy is an initiative that has been utilized to address disparities in the west Alabama Area. Utilizing a small college, a faith based group, and the local chapter of a national sorority with an emphasis in community service, this project has worked to involve African Americans in all levels of cancer prevention and advocacy, including fundraising, education, outreach, and clinical trials.

The Victorious Cancer Support Group is a grassroots faith-based organization that provides cancer related education and support in the west Alabama area. Stillman College is a private HBCU affiliated with the Presbyterian Church. Delta Sigma Theta Sorority, Inc. is a private, not-for-profit organization whose purpose is to provide assistance and support through established programs in local communities throughout the world. The Tuscaloosa Chapter of Delta Sigma Theta Sorority, Inc., The Victorious Cancer Support Group, and Stillman have provided cancer related education and services including smoke free campus initiatives and smoke-free Tuscaloosa advocacy, bone marrow education and registry opportunities, Sister Study Breast Cancer registration, and Cancer Prevention Study 3 registration. Fundraising efforts include support and participation in Race for the Cure, Making Strides Against Breast Cancer and Relay for Life. Advocacy efforts have included visits to lawmakers to discuss funding for cancer research and in support of smoke-free initiatives. Stillman college students have been educated based on health promotion models and have been empowered to take the information back to their communities and to their respective churches and civic groups.

Citation Format: Jacqueline Waldine Currie. Community education; community advocacy. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C96.
Abstract A07: Spontaneous canine mammary cancers: A much-needed model for human basal-like breast cancer and an ideal system to understand myoepithelial cells
Authors: Liu Deli , Xiong Huan , Ellis Angela E. , Northrup Nicole C. , Rodriguez Carlos O. , O'Regan Ruth M. , Dalton Stephen , Zhao Shaying
Published: May 2016

Spontaneous canine mammary cancer represents an excellent model of human breast cancer but is greatly understudied. To better utilize this valuable resource, we performed the first comprehensive characterization of the genome, transcriptome and epigenome of 12 canine mammary cancer cases, including 7 simple carcinomas and 4 complex carcinomas (1).

Simple carcinomas, which histologically match human breast carcinomas, harbor extensive genomic aberrations, many of which faithfully recapitulate key features of human breast cancer. Notably, these tumors closely cluster with human basal-like breast carcinomas from TCGA (2), but not with other intrinsic subtypes, in PAM50 classification with human breast carcinomas. Furthermore, these tumors match the basal-like cancer profile, including MYC amplification, PTEN deletion, BRCA1 mutation, etc. Our results indicate canine simple carcinomas could serve as a much-needed spontaneous cancer model of basal-like breast cancer by effectively bridging the gap between preclinical research and human trials, speeding up drug discovery for the worst subtype of breast cancer.

Canine complex carcinomas, characterized by proliferation of both luminal and myoepithelial cells (rare in human breast cancer), appear to lack genomic abnormalities. Instead, these tumors have ~35 chromatin-modification genes downregulated, and are abnormally enriched with active histone modification H4-acetylation while depleted with repressive histone modification H3K9me3. Our findings indicate that these tumors likely originate from epigenomic alterations instead of genomic lesions. Canine complex carcinomas offer an ideal system to study myoepithelial cells, the second major yet significantly understudied cell lineage of the mammary gland.

References:

1. Liu D, Xiong H, Ellis AE, Northrup NC, Rodriguez CO, Jr., O'Regan RM, et al. Molecular homology and difference between spontaneous canine mammary cancer and human breast cancer. Cancer research. 2014.

2. Cancer Genome Atlas N. Comprehensive molecular portraits of human breast tumours. Nature. 2012;490:61-70.

Citation Format: Deli Liu, Huan Xiong, Angela E. Ellis, Nicole C. Northrup, Carlos O. Rodriguez Jr, Ruth M. O'Regan, Stephen Dalton, Shaying Zhao. Spontaneous canine mammary cancers: A much-needed model for human basal-like breast cancer and an ideal system to understand myoepithelial cells. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A07.
Abstract A31: Integrative differential allelic expression analysis efficiently reveals the biology underlying risk to breast cancer
Authors: Xavier Joana , Russell Roslin , Almeida Bernardo P. , Rosli Nordiana , Rocha Catia , Samarajiwa Shamith , Chin Suet-Feung , Caldas Carlos , Ponder Bruce AJ , Maia Ana-Teresa
Published: May 2016

Breast cancer is the most common cancer affecting women in the developed world. However, the current knowledge of breast cancer genetic risk cannot explain as much as two-thirds of cases. While successful, GWAS have not: (1) contributed to explain the genetic causality of risk; (2) provided an indication of the biological mechanisms involved.

Based on our previous results demonstrating that cis-regulatory variation is involved in breast cancer risk, we have performed whole-genome differential allelic expression (DAE) analysis of sixty-four normal breast tissue samples. We integrated this genome-wide DAE map with published breast cancer GWAS risk loci according to chromosome location, and linkage disequilibrium between DAE SNPs and GWAS associated SNPs.

We found 15 loci (20%) displaying GWAS associated SNPs in strong linkage disequilibrium with SNPs displaying DAE. Potential regulatory SNPs in top two candidate loci are being currently mapped and functionally studied.

We are now integrating the DAE whole-genome map with unpublished GWAS data, to test the efficiency of this approach to help prioritise loci for further risk-association validation. The large overlap between GWAS and DAE data confirms the importance of cis-regulation in the biology of breast cancer risk and provides a new powerful tool to prioritise and functionally analyse risk loci identified through GWAS.

Citation Format: Joana Xavier, Roslin Russell, Bernardo P. Almeida, Nordiana Rosli, Catia Rocha, Shamith Samarajiwa, Suet-Feung Chin, Carlos Caldas, Bruce AJ Ponder, Ana-Teresa Maia. Integrative differential allelic expression analysis efficiently reveals the biology underlying risk to breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A31.
Abstract A34: BRCA1 and BRCA2 mutation spectrum across 5, 509 high-risk individuals identifies pathogenic variants associated with ethnicity, age of diagnosis, and type of cancer
Authors: Girgis Andrew H. , Wang Marina , Fine Alexa , Zakoor Kathleen-Rose , Khalouei Sam , Charames George , Lerner-Ellis Jordan
Published: May 2016

Hereditary Breast and Ovarian Cancer Sydrome (HBOC) accounts for approximately 5-10% of breast and ovarian cancer cases and germline mutations of the BRCA1 and BRCA2 genes confer substantially increased risk. However, the risk of developing cancer, the type of cancer and the associated age at diagnosis vary depending on the type of mutation carried and the individual's ethnic background and gender. Screening of BRCA1 and BRCA2 mutations was conducted on 5, 512 high-risk individuals with a prior probability of carrying a pathogenic mutation (>10% chance) from the Advanced Molecular Diagnostics Laboratory (AMDL) (Mount Sinai Hospital, Toronto). Information on age, type of cancer diagnosed and age at diagnosis, ethnicity and family history were collected. Cumulative incidence competing risk and Fine-Gray proportional hazard regression analyses were generated to determine factors associated with earlier diagnosis of cancer. Among 5,029 women and 480 men who underwent testing, a total of 845 unique variants were identified of which, 289 (34.2%) are pathogenic. There were 603 female mutation carriers, of these, 303 were affected with breast or ovarian cancer (50%), 16 with another cancer (2.25%) and 284 were unaffected (47.1%). We also identified 20 different ethnic groups presenting with at least 3 unique variants. Six ethnic groups carried at least one variant associated with an earlier diagnosis of cancer and differential breast or ovarian cancer incidence. For instance, among the Ashkenazi Jewish cohort, the c.68_69del variant was associated with significantly earlier age at diagnosis for ovarian cancer incidence (Gray's test = 40.6; Fine-Gray HR = 1.12, 95% CI = 1.05 – 1.31). By screening a diverse cohort of high-risk individuals for BRCA1 and BRCA2 mutations, we identified pathogenic variants associated with an earlier age of diagnosis and differential incidence of breast or ovarian cancer among unique ethnic groups.

Citation Format: Andrew H. Girgis, Marina Wang, Alexa Fine Kathleen-Rose ZakoorSam Khalouei, George Charames, Jordan Lerner-Ellis. BRCA1 and BRCA2 mutation spectrum across 5, 509 high-risk individuals identifies pathogenic variants associated with ethnicity, age of diagnosis, and type of cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A34.
Abstract A44: Clinical significance of ESR1 mutations by cell-free DNA in recurrent/metastatic breast cancer
Authors: Takeshita Takashi , Yamamoto Yutaka , Yamamoto-Ibusuki Mutsuko , Inao Toko , Sueta Aiko , Fujiwara Saori , Iwase Hirotaka
Published: May 2016

Purpose: We aimed to develop a droplet digital Polymerase Chain Reaction (ddPCR)-based method for the sensitive detection of estrogen receptor (ER) α (ESR1) mutations of tumor tissues and the corresponding cell-free DNA (cfDNA) in recurrent/ metastatic breast cancer.

Experimental Design: We investigated a total of 325 tumor specimens (270 primary breast cancer specimens and 55 ER-positive recurrent/metastatic tumor specimens, in which 33 recurrent/ metastatic tumor specimens had the corresponding plasma). We investigated the quantification of rare ESR1 mutations, four representative types, Y537S, Y537N, Y537C, and D538G in 33 extracted genomic DNA (gDNA) and its corresponding cfDNA using ddPCR system that simultaneously performed thousands of PCRs on a nanoliter scale.

Results: A total of 33 (60 %) of 55 recurrent/ metastatic breast cancer specimens had the corresponding plasma which were evaluated for ESR1 mutations' analysis for cfDNA. We verified the correlation of each ESR1 mutation between cfDNA and tissue gDNA. Only ESR1 Y537C was correlated between cfDNA and tissue gDNA (r = 0.56, P = 0.0006). ESR1 Y537S in tissue gDNA were tend to be correlated Y537N in cfDNA (r = 0.35, P = 0.043). CEA (Carcinoembryonic antigen), which is one of the representative breast cancer tumor markers, was correlated with ESR1 Y537S in cfDNA (r = 0.74, P < 0.0001) and tend to be correlated with Y537S in tissue gDNA (r = 0.36, P = 0.033) and D538G in cfDNA (r = 0.54, P = 0.0011). We also evaluated the correlation between the presence of ESR1 mutations and best overall response (BOR) to post-endocrine therapy. BOR to post-endocrine therapy was 25 stable disease (SD) and 8 progressive disease (PD) in 33 patients. Using each selected cut-off, a total of 4 (50%) of 8 PD patients had ESR1 cfDNA mutations as follow: each patient had Y537S, Y537N, D538G, and double mutations (Y537S and D538G). The presence of ESR1 cfDNA mutations was much higher in PD group, compared with SD group (P = 0.0073)

Conclusions: We demonstrated the sensitive detection and accurate quantification of low frequency ESR1 mutations in 33 tumor tissues and the corresponding cell-free DNA (cfDNA) using ddPCR assay in recurrent/ metastatic breast cancer. Our results highlight that ESR1 mutations may be of clinical relevance for metastatic breast cancer patient.

Citation Format: Takashi Takeshita, Yutaka Yamamoto, Mutsuko Yamamoto-Ibusuki, Toko Inao, Aiko Sueta, Saori Fujiwara, Hirotaka Iwase. Clinical significance of ESR1 mutations by cell-free DNA in recurrent/metastatic breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A44.
Abstract A54: Met and its ligand HGF predict radiotherapy response in premenopausal breast cancer patients
Authors: Veenstra Cynthia , Pérez-Tenorio Gizeh , Nordensköljd Bo , Fornander Tommy , Stål Olle
Published: May 2016

Post-operative radiotherapy effectively decreases the risk for loco-regional recurrence in breast cancer. However, some patients display signs of radioresistance. There are few biomarkers used in the clinic today to predict response to radiotherapy, and patients continue to receive unnecessary treatment. Studies propose a role for the receptor tyrosine kinase Met and its ligand HGF in radioresistance. Therefore, it was aimed in this study to determine MET and HGF copy numbers, Met and HGF expression, and phosphorylated Met expression in breast cancers to elucidate Met and HGF's role in radiotherapy response. MET and HGF copy numbers were determined by digital droplet PCR in 205 pre-menopausal patients, randomized to receive either radio- or chemotherapy. Immunohistochemical staining of Met, phosphorylated Met, and HGF could be performed on 228 tumor tissue samples in this cohort. Increased MET and HGF copy numbers, more than two copies, were detected in 33% and 21% of the tumors, respectively. MET and HGF amplification, more than three copies, was detected in 8% and 7% of the tumors, respectively. Interestingly, patients with tumours with MET amplification tended to relapse at a higher rate than patients without amplification. This was more prominent in patients with triple-negative breast cancer, where both MET amplification and increased copy number were correlated with a shorter recurrence-free survival. High stromal HGF expression, but not HGF copy number, was also shown to be correlated with shorter survival. Both high cytoplasmic phosphorylated Met and high cytoplasmic HGF predicted better response to radiotherapy, compared with low expression. Similar results were seen for MET and HGF increased copy number. A tendency of opposite results were obtained with total membranous Met and stromal HGF. Patients with tumors expressing low levels of these proteins had more benefit from radiotherapy. This suggests that MET and HGF copy gain is not enough for a favorable radiotherapy response, the status of the resulting proteins is additionally of importance.

Citation Format: Cynthia Veenstra, Gizeh Pérez-Tenorio, Bo Nordensköljd, Tommy Fornander, Olle Stål. Met and its ligand HGF predict radiotherapy response in premenopausal breast cancer patients. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A54.
Abstract B40: Transcription factor Snail mediates EMT by altering vesicular trafficking protein Rab25
Authors: Mitra Shreya , Federico Lorenzo , Mills Gordon B.
Published: May 2016

Epithelial cells maintain intercellular communication directly by cell-cell, cell-ECM interaction and indirectly by paracrine secretion of extracellular messengers either as free molecules or via exosomes. The vesicular trafficking machinery is an integral part of such communication, paralleling digital cables that transmit the information bytes to the correct hub. During the process of EMT, derailing of the trafficking machinery leads to a systemic breakdown of intra and inter-cellular communication pathways. The purpose of the current study is to elucidate the functional role of Rab25, a key member of the vesicular trafficking machinery in mediating EMT-MET processes during breast cancer progression.

Aberrant endocytosis is a new hallmark of cancer. Rab GTPases are the primary regulators of endocytosis. Many members of this large family are implicated in a wide array of cancers including breast cancer. Specifically, Rab25, a GTPase associated with the recycling endosomes, is deregulated in most epithelial cancers. Rab25 appears to function both as a tumor suppressor and an oncogene in a context dependent manner.

We found that Rab25 is lost in Claudin Low tumors as well as in representative cell lines such as the MDA MB231. Rab25 is a robust and sufficient marker of breast cancers and cell lines with an increased EMT signature. Additionally, in immortalized human mammary epithelial cell lines (HMLE), induction of EMT by overexpression of Snail1 completely obliterates Rab25 protein. Exogenous re-expression of Rab25 dramatically rescues these cells from Snail driven invasion through Matrigel. However this Snail dependent regulation is unique only to TN and Claudin Low tumors and does not hold true for hormone receptor positive tumors. Further, analysis of RNA Seq data from a MMTV mouse model showed that tumors enriched in EMT markers and by corollary with low CDH and claudins, also lost Rab25 transcripts.

Snail mediated transcriptional repression targets recycling endosomal proteins such as Rab25 to decrease delivery of junction proteins that facilitate cell-cell communication to the appropriate compartment. In parallel, it potentially enhances paracrine regulation by secreted exosomes. Overall, our study shows presence and absence of Rab25 markedly alters cell-cell communication, which is essential for maintenance of epithelial features of cells. Rab25 could be a prognostic marker and a therapeutic target for a subset of patients with increased risk of metastatic disease.

Citation Format: Shreya Mitra, Lorenzo Federico, Gordon B. Mills. Transcription factor Snail mediates EMT by altering vesicular trafficking protein Rab25. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B40.
Abstract IA20: Genomics of a STAT1 knockout mouse model of human ER+ breast cancer
Authors: Mardis Elaine , Griffith Obi L. , Szeman Ruby Chan , Griffith Malachi , Krysiak Kilannin , Skidmore Zachary , Hundal Jasreet , Allen Julie A. , Cora Arthur , Miceli Alexander P. , Schmidt Heather , Trani Lee , Kanchi Krishna-Latha , Miller Christopher A. , Larson David E. , Fulton Robert S. , Wilson Richard K. , Schreiber Robert D.
Published: May 2016

Estrogen receptor alpha positive luminal breast cancers are the most frequent subtype of breast cancer. Previous work has established that Stat1-/- mouse mammary tumor model recapitulates signaling, expression and phenotypic alterations observed in this subtype of human breast cancers. To identify transforming events that contribute to tumorigenesis, we performed whole genome sequencing of 22 Stat1-/- primary mammary tumors and cell lines. We discovered a novel hotspot of somatic mutations in 100% of tumors that resulted in a truncated form of the prolactin receptor (Prlr). Targeted sequence analysis identified similar mutations in 77.8% of ductal carcinoma in situ. Co-expression of truncated and full-length Prlr in normal cells led to activation of oncogenic Stat3 and Stat5 as well as cellular transformation. In conclusion, truncating mutations of Prlr drive tumor development in a model of human ERa+ breast cancer and should be considered as novel antitumor targets.

Citation Format: Elaine Mardis, Obi L. Griffith, Ruby Chan Szeman, Malachi Griffith, Kilannin Krysiak, Zachary Skidmore, Jasreet Hundal, Julie A. Allen, Arthur Cora, Alexander P. Miceli, Heather Schmidt, Lee Trani, Krishna-Latha Kanchi, Christopher A. Miller, David E. Larson, Robert S. Fulton, Richard K. Wilson, Robert D. Schreiber. Genomics of a STAT1 knockout mouse model of human ER+ breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr IA20.
Abstract IA30: Insights into metabolome of breast cancer
Authors: Sreekumar Arun
Published: May 2016

Metabolomics describes the science of quantifying the levels of metabolites (e.g., small molecules <1kDa) that are the byproducts of cellular metabolism. Unlike genomics, transcriptomics and proteomics, metabolomic analysis involves reduced complexity because of fewer endpoints and allows the assay of composite downstream outputs from complex interconnected cellular processes. These aspects both facilitate bioinformatic analysis and may accentuate subtle upstream gene/protein level alterations. Comparisons of metabolomic profiles from tissues or bodily fluids from one diseased state to another permits the identification of pathways and processes that may drive the phenotype in question.

Our recent profiling of 200 metabolites using mass spectrometry in benign and malignant breast tissues from ancestry-verified AA and EA women, revealed altered levels of specific metabolites (or associated pathways) in AA TN BCa compared to EA TN tumors. Key among them was elevated levels of 2- hydroxyglutaric acid (2-HG), a mitochondrial onco-metabolite that was elevated in a subset of predominantly AA TN BCa with poor clinical outcome. Tumors with high 2-HG had a distinct methylation signature exhibiting activation of the MYC oncogene and were associated with elevated levels of fatty acids and lipids. Taken together, we expect these studies help understand the disparity in the clinical behavior of TN BCa. Further, we expect biochemical profiles to be useful in stratifying tumors for various pathway-based treatment regimens.

Citation Format: Arun Sreekumar. Insights into metabolome of breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr IA30.
Abstract PR06: Modeling the tumor microenvironment to identify novel loss of function mutations in breast cancer progression
Authors: Peck Barrie , Maguire Sarah , Morrison Eamonn , Wai Patty , Natrajan Rachael
Published: May 2016

Recent next generation sequencing studies have comprehensively mapped the genetic landscape of breast cancer and revealed that only a small number of genes are recurrently mutated in more than 10% of unselected tumors (i.e. TP53, PIK3CA and GATA3), and that the vast majority of recurrent mutations occur at low frequencies. Although some have been shown to be drivers (i.e. confer a selective advantage), such as oncogenic ERBB2 mutations, there is a myriad of significantly altered lower frequency mutations whose functional impact is unknown.

We utilized a functional genomics approach silencing the 200 most frequently mutated genes in breast cancer in 3D spheroid cultures that more accurately recapitulate in vivo like conditions, using the MCF10A progression series cell line panel to identify novel loss of function mutations that affect breast cancer progression from non-malignant to highly invasive disease. Genes whose silencing significantly altered spheroid growth were integrated with comprehensive copy number and mutation data in order to analyze the impact of these genes in concert with additional driver alterations in genes such as TP53 and PIK3CA mutations.

We identified 11 genes whose silencing with siRNA had a significant effect on growth in two or more cell lines in 3D, including FMN2, FOXA1, NIPBL and CREBBP. Silencing of FMN2 increased spheroid growth in the invasive cell lines only, suggesting loss of function mutations are a later event in breast cancer progression. A second targeted validation screen showed that silencing of a cohort of these genes had limited effect under traditional 2D culture conditions, for example, silencing of maltase-glucoamylase (MGAM) resulted in increased growth in AT1 and DCIS.com cells in 3D while having no effect in 2D; an effect that was recapitulated by treating cells with an established MGAM inhibitor. Furthermore, loss of NIPBL significantly increased spheroid growth in cells harboring TP53 nuclear accumulation, and was significantly co-mutated in TP53 mutant primary tumors, suggestive of epistasis. Integrating genes that when silenced decreased spheroid growth with mutation status in the cell lines identified 3D specific oncogenic dependencies with PIK3CA and novel SZT2 mutations.

Using a functional genomic approach in 3D models we have identified recurrently mutated genes whose loss or gain of function contribute to breast cancer progression and furthermore may be epistatic or cooperate with established driver mutations in breast cancer.

Citation Format: Barrie Peck, Sarah Maguire, Eamonn Morrison, Patty Wai, Rachael Natrajan. Modeling the tumor microenvironment to identify novel loss of function mutations in breast cancer progression. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr PR06.
Abstract A06: Exploring mechanisms of colorectal tumor radioresistance in organoids
Authors: Martin Maria Laura , Hua Guoqiang , Zeng Zhaoshi , Paty Philip B.
Published: May 2016

Colorectal cancer is the third most common cancer in men and the second in women worldwide. It is currently proposed that a population of tumor stem cells that are resistant to radiotherapy leads to tumor recurrence. Accumulating evidence indicates that a transformed lgr5+ [leucine-rich-repeat-containing G-protein-coupled receptor 5] cell at the base of the colonic crypt represents the cell of origin of colorectal cancer. However, mechanisms underlying colorectal cancer radioresistance are not completely understood. The purpose of this study is to elucidate mechanisms of resistance to radiation of normal and tumor stem cells. Using lgr5-lacZ transgenic mice we show that lgr5+ stem cells in the distal part of the large intestine are significantly more radiation resistant than their counterpart in the small intestine. In agreement with in vivo data, isolated colonic crypts are also significantly more resistant to radiation than small intestinal crypts in vitro. Additionally, using a mouse model of colitis-associated colon adenoma (azoxymethane - dextran sulfate sodium mouse model) we determined that crypt-like structures derived from mouse adenoma are even more radioresistant than normal colon. These results validate intestinal organoids as a model for in vivo radiation responsiveness. The next step is to elucidate mechanisms of radiation resistance of human colorectal stem cell organoids derived from normal tissues and tumors. The findings from this work will shed light on properties of lgr5+ tumor stem cells that may be relevant when devising strategies to reduce tumor burden.

Citation Format: Maria Laura Martin, Guoqiang Hua, Zhaoshi Zeng, Philip B. Paty. Exploring mechanisms of colorectal tumor radioresistance in organoids. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr A06.
Abstract B18: Strand-specific in vivo screen of cancer-associated miRNAs unveils key drivers and oncogenic targets
Authors: Ge Yejing , Zhang Liang , Nikolova Maria , Reva Boris , Fuchs Elaine
Published: May 2016

MiRNAs are evolutionarily conserved small non-coding RNAs that orchestrate a wide spectrum of physiological and pathological processes in stem cells (SCs) and human cancers. Intimately wired into oncogenic and tumor suppressive networks, miRs are valuable as not only diagnostic biomarkers but also therapeutic targets. Squamous cell carcinomas (SCCs) are among the most life-threatening human cancers world-wide. Using skin as paradigm, we describe the first panoramic view of miRs during the development, homeostasis and malignant transformation of skin epithelium, whose SCs are the target of most common SCCs. Focusing on abundant and enriched miRs in SCC-SCs versus normal skin SCs, we devised lentiviral miR expression platform and conducted pooled in vivo functional screens for oncomiRs in mice. Deep sequencing of genomic DNA from basal progenitors of tumors or unaffected skin epithelium revealed preferential enrichment of 29/169 miRs within the tumors. We followed up with the top hits and showed candidate miRs are indeed aberrantly induced in both mouse and human SCCs. After functionally documenting their tumor-promoting roles in mouse SCCs in vivo and human xenografts, we applied CRISPR technology to ablate the miR loci in cells derived from these SCCs, and then used lentiviral delivery methods to carry out specific miR rescues of the tumorigenic phenotype. To look for candidate targets of newly identified oncomiRs, we analyzed TCGA database that are inversely correlated with our candidate miR as well as genes that are de-repressed upon miR deletion. We discovered potent tumor suppressors whose knockdown rescued the deficit in tumor formation from oncomiR-deficient cells and whose overexpression reversed miR-driven tumorigenesis. Furthermore, we demonstrated CRISPR-mediated deletion of the endogenous miRNA binding site renders the target cells no longer sensitive to miRNA regulation. Finally, we pinpointed the cellular mechanism of how miR-target regulates SCC progression. Empowered by mouse genetics and high throughput approaches, our study has unveiled a rich set of putative miRs that drive skin SCC malignancy, and discovered their oncogenic targets. These findings shed new light on increasingly important oncomiR loci and its action on a devastating cancer.

Citation Format: Yejing Ge, Liang Zhang, Maria Nikolova, Boris Reva, Elaine Fuchs. Strand-specific in vivo screen of cancer-associated miRNAs unveils key drivers and oncogenic targets. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr B18.
Abstract B37: hnRNP K in acute promyelocytic leukemia cells NB4 and NB4-R2: Involvement in cell survival and differentiation
Authors: Padovani Karina Stringhetta , Annichini María Sol Brassesco , Rego Eduardo Magalhães , Curti Carlos , Greene Lewis Joel , Leopoldino Andréia Machado
Published: May 2016

hnRNP K has been reported to be overexpressed in myeloid leukemia and it is downregulated during all-trans retinoic acid (ATRA) induced differentiation of Acute Promyelocytic Leukemia (APL) cells. The aim of the present study was to establish role of hnRNP K in APL using responsive (NB4) and resistant (NB4-R2) cells to the all-trans retinoic acid treatment as well as the possible role of hnRNPK in ATRA-induced cellular differentiation. After demonstration, by Western blotting analysis, that hnRNP K is overexpressed (10 fold) in APL (NB4 and NB4-R2) cell lines compared to controls (bone marrow and polymorphonuclear cells), we knocked-down the protein by short hairpin RNA (shRNA) interference in these cell lines and assessed involvement of hnRNP K in ATRA-induced differentiation, by flow cytometry in cells incubated with Cd11bPE antibody, as well as the contribution of hnRNP K to proliferation, with growth curve, using Trypan Blue, and survival, by propidium iodide incorporation analysis in flow cytometer. The knockdown of hnRNP K in NB4 (72%) and NB4-R2 (60%) leads to loss of viability mainly in NB4-R2 (42,43% of viability) vs NB4 (75,33% of viability). The loss of viability was more accentuated after ATRA treatment, NB4-R2 (6,13% of viability) vs NB4 (70% of viability). hnRNP K knockdown increases APL cells differentiation and was more accentuated in association with ATRA treatment, NB4-R2 (+59,13%) vs NB4 ( +14,06%). Furthermore, knockdown of hnRNP K leads to decreased in proliferation in NB4 (-95,98%) and NB4-R2 (-97,5%). hnRNP K knockdown promotes decrease of Bcl-xl, PML-RARα, procaspase-3 and increases of SET protein levels in both cells, demonstrated by Western blotting. The extracellular signal-regulated kinase ERK is a positive hnRNP K regulator, so the treatment with the ERK inhibitor at 10 μM U0126 produces effects similar to hnRNP K knockdown on cell viability in NB4-R2 cells, and in levels of BCL-xl and SET proteins. We concluded that, hnRNP K knockdown decreases the cell proliferation and viability of NB4 and NB4-R2 cells and increases cell differentiation, via MEK-ERK-hnRNP K-SET signaling. hnRNP K represent a potential target in APL ATRA resistant cells.

Citation Format: Karina Stringhetta Padovani, María Sol Brassesco Annichini, Eduardo Magalhães Rego, Carlos Curti, Lewis Joel Greene, Andréia Machado Leopoldino. hnRNP K in acute promyelocytic leukemia cells NB4 and NB4-R2: Involvement in cell survival and differentiation. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr B37.
Abstract IA23: Hippo/YAP signaling in stem cells and cancer
Authors: Camargo Fernando
Published: May 2016

The long-term goals of the Camargo laboratory are to provide basic insight into conserved mechanisms underlying size and growth control. We are particularly interested in the pathways that somatic stem and progenitors cells utilize to sense and respond to growth inputs in vivo. We utilize the mouse as a genetic model to study pathway function and to dissect the mechanisms by which growth control is coordinated. We also employ three-dimensional primary culture, biochemistry, and high-throughpout genetic interrogation in vitro to identify novel growth-control genes and to provide basic molecular mechanisms underlying our in vivo observations. Additionally, my lab is pursuing the development of novel technologies for lineage tracing of mammalian stem cells. We are particularly interested in studying the function of the Hippo/YAP signaling pathway and its effects on tissue size, homeostasis and cancer. We have demonstrated that Hippo signaling can be a very potent regulator of organ size in mice and have provided a conceptual link between organ size regulation and stem cell activity through Hippo signals. Studies exploring the molecular basis of YAP-driven phenotypes will be discussed.

Citation Format: Fernando Camargo. Hippo/YAP signaling in stem cells and cancer. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr IA23.
Abstract IA32: Identification and therapeutic targeting of poor prognosis subtypes in colorectal cancer
Authors: Batlle Eduard
Published: May 2016

About 40-50% of Colorectal Cancer (CRC) patients with locally advanced disease show resistance to therapy and develop recurrent cancer over the course of their treatment. Current CRC staging based on histopathology and imaging has a limited ability to predict prognosis. A major advance has been the elaboration of molecular classifications based on global gene expression profiles, which have defined CRC subtypes displaying resistance to therapy and poor prognosis. We have recently evaluated these molecular classification systems and discovered that their predictive power arises from genes expressed by stromal cells rather than by epithelial tumor cells. Our functional dissection of CRC progression shows that metastasis relies on a tumor cell non-autonomous program driven by TGF-beta in the microenvironment. Virtually all poor prognosis CRC subtypes upregulate this stromal gene program, which confers a survival advantage to metastatic stem cells during organ colonization. Here I will discuss our latest data about the dichotomy of TGF-beta signaling in epithelial versus stromal cells during CRC progression and the use of patient derived tumor organoids and mouse models to test the efficacy of anti-TGF-beta therapies for CRC treatment.

Citation Format: Eduard Batlle. Identification and therapeutic targeting of poor prognosis subtypes in colorectal cancer. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr IA32.