bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1664: Alpha-tocopheryloxyacetic acid (aTEA) induced immune activation synergizes with radiation therapy to treat primary and metastatic murine mammary carcinoma
Authors: Walker Joshua M. , Barragan Diego M. , Kasiewicz Melissa J. , Thomas Charles R. , Redmond William L.
Published: July 2016

Immunotherapy has now emerged as a promising treatment for metastatic cancer. However, immunotherapy for advanced stage breast carcinoma remains an unmet need. Here we demonstrate that the novel immunomodulator alpha-tocopheryloxyacetic acid (aTEA) synergizes with radiation therapy (RT) in a metastatic murine mammary carcinoma model to improve tumor control more than each individual therapy, and we propose a mechanism based on the stimulation of type I interferons by aTEA.

For in-vivo studies, C57BL/6 mice bearing 4T1 murine mammary carcinoma lesions were treated with dietary aTEA, 20 Gy x 2 fractions ionizing radiotherapy, or the combination of aTEA/RT. Immune activation in animals treated with dietary aTEA was determined by analyzing the percentage of proliferating CD4 and CD8 T cells using a Ki-67 assay. Pulmonary metastatic burden was determined using a clonogenic metastasis assay. For in-vitro studies, murine mammary carcinoma cell lines were treated with aTEA or LPS and whole cell lysates were analyzed by Western blot. Expression of interferon regulation factor 3 (IRF3) pathway proteins, including phospho-TANK binding protein kinase 1 (TBK1) and stimulator of interferon genes (STING) were determined.

Our results indicate that treatment with the combination of aTEA and RT significantly improves tumor control compared to either treatment alone. Combination therapy resulted in complete and durable tumor regression in a subset of animals treated, an effect not observed with aTEA or RT alone. Dietary administration of aTEA stimulates proliferation of both CD4 and CD8 T cells and significantly reduces metastatic burden in 4T1 tumor bearing mice. This immune stimulatory effect of aTEA appears to be mediated by reactive oxygen species (ROS) production and release of type I interferons through a STING mediated pathway.

These preliminary results suggest that the combination of aTEA and ionizing radiation may be a viable therapy for the treatment of metastatic breast carcinoma. This therapeutic combination may provide more durable response to radiotherapy while simultaneously reducing further metastatic spread.

Citation Format: Joshua M. Walker, Diego M. Barragan, Melissa J. Kasiewicz, Charles R. Thomas, William L. Redmond. Alpha-tocopheryloxyacetic acid (aTEA) induced immune activation synergizes with radiation therapy to treat primary and metastatic murine mammary carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1664.
Abstract 169: Drug resistance gene expression pathways in primary refractory breast cancer
Authors: Kan Charlene , Parsai Shikha , Avril Stefanie , Lyons Janice , Gilmore Hannah , Zhang Junran , Harris Lyndsay
Published: July 2016

Purpose/Objective:

Breast cancer is a collection of diseases with distinct molecular subtypes with differing prognoses. Clinically, there is a group of therapy resistant breast cancers characterized by resistance to conventional chemo- and radiotherapy with short overall survival and poor prognosis, which we termed primary refractory breast cancer (PRBC). We hypothesized that PRBC is characterized by specific genomic changes that may contribute to therapy resistance. The aim of this study was to identify changes in gene expression profiles of PRBC compared to triple negative (TNBC) and ER+/-PR positive (HR) breast cancer cohorts.

Methods:

PRBC was defined as patients with an initial diagnosis of Stage I-III breast cancer who either I) developed metastatic disease within 6 months of completing treatment or II) died of breast cancer within two years of initial diagnosis. Formalin-fixed paraffin-embedded (FFPE) tissue was obtained under an IRB approved protocol 01-13-43c. RNA was extracted from macro-dissected FFPE tumor tissue. Gene expression profiling was performed with Affymetrix Human Transcriptome Array 2.0 and gene signatures were analyzed using a single sample gene set enrichment methodology. Gene signatures of PRBC patients were compared to signatures of two TNBC and HR cohorts with gene expression data generated by identical methodology.

Results:

A total of nineteen samples from eight patients had sufficient tumor material to obtain RNA. The median age at diagnosis was 44.3 years, 62.5% were triple negative. At initial diagnosis the stage ranged from IA to IIIC. Sixty-three percent received neoadjuvant chemotherapy. The median time to relapse was 8.4 months and median time to death 1.7 years. Genomic analysis identified highly significant (p<10-6) increased expression of ABC transporters, hypoxia, interferon, DNA repair and AKT signatures compared to control cohorts.

Conclusions:

PRBC is characterized by significant upregulation of multiple gene expression signatures important in drug resistance including ABC transporters, hypoxia, AKT and DNA repair pathways. Confirmation of these results would allow the development of alternative treatment strategies for PRBC to help improve the devastatingly poor prognosis of this subgroup of patients.

Citation Format: Charlene Kan, Shikha Parsai, Stefanie Avril, Janice Lyons, Hannah Gilmore, Junran Zhang, Lyndsay Harris. Drug resistance gene expression pathways in primary refractory breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 169.
Abstract 1700: Novel microfluidic blood-brain niche to study breast cancer metastasis to the brain
Authors: Altemus Megan , Leung Brendan , Morikawa Aki , Dziubinski Michele , Castro Maria , Merajver Sofia
Published: July 2016

Metastasis from the primary tumor site to the brain is the most lethal complication of advanced cancer. Once a patient has developed brain metastasis, treatment involves surgical resection or radiation and is often only palliative. Poor prognosis following these therapies as well as the presence of concurrent disease outside of the nervous system emphasize the need for new systemic therapies that can reach and are active within the brain. In order to study the process of brain metastasis and develop potential therapies, models that mimic the human blood-brain niche must be used. Models currently utilized are murine in vivo models and various in vitro methods that do not accommodate all the biophysical characteristics of a blood-brain barrier. In vivo murine models are costly, time intensive, very slow to manifest metastases, and the metastatic process is seldom amenable to monitoring in real time. Current in vitro models are faster and more cost effective; however the models currently used do not have the same micro-environment complexity as “live” models. Here we describe a novel microfluidic device that accurately mimics the physical and cellular components of the human blood-brain niche to study the brain metastatic process.

This device is composed of two chambers separated by a porous membrane. The top chamber and apical side of the membrane is seeded with human brain endothelial cells with and uses flow to mimic shear stress encountered within the vasculature. Cancer cells are introduced into this chamber in which they adhere to and migrate through the endothelium into the bottom chamber. The bottom chamber contains astrocytes suspended in a collagen gel to mimic the brain stroma and provide room for invading cancer cells to colonize and grow. Barrier integrity is monitored using TEER (trans-endothelial electrical resistance), and fluctuates as the tight junctions of the endothelium are compromised by invading cancer cells. Throughout all time points, from introduction into the flow chamber, adherence to the endothelium, extravasation through the barrier, migration into the stroma, and proliferation the cancer cells can be monitored via microscopy or TEER.

This device provides a powerful novel tool to study the brain metastatic process and can be used to determine differences in brain metastatic potential of various cell lines or patient derived material, study the molecular mechanisms that promote brain metastasis, and test potential new therapies.

Citation Format: Megan Altemus, Brendan Leung, Aki Morikawa, Michele Dziubinski, Maria Castro, Sofia Merajver. Novel microfluidic blood-brain niche to study breast cancer metastasis to the brain. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1700.
Abstract 1702: Sucrose nonfermenting 1-related kinase (SNRK) expression in ovarian cancer and correlation with clinical features
Authors: Hopp Elizabeth E. , Bishop Erin , Cossette Stephanie , Ramchandran Ramani
Published: July 2016

Objective: Human omental adipocytes promote migration and invasion of ovarian cancer cells and result in alterations in metabolism including increased AMP-activated protein kinase (AMPK) and b-oxidation, which allow for use of lipids as an energy source. Sucrose nonfermenting 1-related kinase (SNRK) is a member of the AMPK family of serine/threonine kinases, which are activated by starvation and stress conditions. The goal of this study is to describe the expression of SNRK in human ovarian cancer tissue.

Methods: Tissue was collected from patients undergoing surgery for serous ovarian cancer or benign indications. Immunohistochemistry (IHC) was used to detect SNRK expression. SNRK+ cells were compared between benign and malignant tissue, and statistical significance between positivity and clinicopathologic variables was determined using the Mann-Whitney U test.

Results: In the 31 samples analyzed, SNRK demonstrates a nuclear staining pattern. IHC shows increased SNRK+ cells in malignant tissue versus benign tissue (42.0% versus 31.3% positive nuclei, p<0.001). When examining patient characteristics, the malignant samples with the lowest percentage of SNRK+ nuclei were stage IIIB-IV with a high incidence of recurrence and death due to disease.

Conclusions: This is the first study to describe SNRK expression in ovarian cancer tissue. We show that SNRK has a nuclear staining pattern and that expression is greater in malignant ovarian tissue compared to benign ovarian tissue, which may be due to more metabolic stress on cells with higher proliferation rates. SNRK expression appears to be lower in those with a higher disease stage and poor outcome potentially secondary to metabolic changes that occur once the disease metastasizes. We are currently examining SNRK expression in metastatic omental tumors in order to further explore expression differences between primary versus metastatic disease sites.

Citation Format: Elizabeth E. Hopp, Erin Bishop, Stephanie Cossette, Ramani Ramchandran. Sucrose nonfermenting 1-related kinase (SNRK) expression in ovarian cancer and correlation with clinical features. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1702.
Abstract 1751: Coffee and tea intake and risk of endometrial cancer in the Epidemiology of Endometrial Cancer Consortium (E2C2)
Authors: Crous-Bou Marta ,   Epidemiology of Endometrial Cancer Consortium (E2C2), De Vivo Immaculata
Published: July 2016

Background: Endometrial cancer (EC) is the most common gynecological malignancy in developed countries. Well-known risk factors for EC include obesity and elevated levels of estrogen and insulin. Coffee and tea are the most widely consumed beverages in the world, after water. Both are a complex mixture of chemicals with potential antimutagenic and antioxidant properties. Previous studies have reported an inverse association between coffee consumption and circulating levels of estrogen and C-peptide, a marker of insulin secretion, both involved in endometrial carcinogenesis. The presence of antioxidants and other chemopreventive compounds in coffee and tea may have an anticarcinogenic effect. Thus, coffee and tea drinking may decrease the risk of EC.

Objective: To examine the association between coffee and tea intake and endometrial cancer risk.

Patients and Methods: We combined individual-level data from 24 epidemiologic studies (10 Cohort studies, 14 Case-Control studies) from the Epidemiology of Endometrial Cancer (E2C2) Consortium and performed a pooled analysis of 11,424 endometrial cancer cases and 28,388 controls. Logistic regression models were used to calculate ORs and the corresponding 95% CI. All models were adjusted for potential confounders.

Results and Conclusions: Increased coffee consumption was associated with a reduced risk of endometrial cancer: compared to non-coffee drinkers, the pooled OR for those who drank more than 1 cup of coffee per day was 0.79 (95%CI = 0.71-0.87, p = 5.48×10−6). The association is mainly observed in cohort studies and remains significant after adjusting for potential confounders. We found no association between tea consumption and endometrial cancer risk.

Citation Format: Marta Crous-Bou, Epidemiology of Endometrial Cancer Consortium (E2C2), Immaculata De Vivo. Coffee and tea intake and risk of endometrial cancer in the Epidemiology of Endometrial Cancer Consortium (E2C2). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1751.
Abstract 1756: Marijuana use and serum testosterone concentrations among U.S. males
Authors: McGlynn Katherine A.
Published: July 2016

Background: Testicular germ cell tumors (TGCT) of young men can be histologically divided into nonseminomas and seminomas. Although TGCTs are thought to be hormonally-related, very few risk factors have been identified. Recently, however, marijuana use has been linked to risk of nonseminoma, which has peak incidence at a younger age (25 years) than does seminoma (35 years). Whether marijuana may be related to nonseminoma via an effect on testosterone concentrations is unknown. Thus, an analysis of U.S. males was conducted, using data from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) of the NCHS, CDC.

Methods: Data from 2409 males aged >20 years were included in the analysis. Serum total testosterone (T) concentrations, determined using liquid chromatography-tandem mass spectrometry, were log transformed for statistical analyses. Marijuana use was categorized as: never, current (use on at least one day in prior 30 days) and past (no use within prior 30 days). Regular use was defined as use at least once a month for > 1 year. Covariates included age, body mass index, race/ethnicity, cigarette smoking status and time of day of phlebotomy. Adjusted mean T concentrations were compared among marijuana use categories using weighted multiple linear regression analysis accounting for the complex sample design of NHANES. In addition to the overall analysis, models were stratified by age (20-30 years, >30 years).

Results: Mean T concentration did not differ between never- and ever-users of marijuana (p = 0.62), but did differ between never-users and regular-users (2.56 ng/mL vs 2.59 ng/mL, p = 0.03) and between never-users and current-users (2.60 ng/mL, p = 0.007). In the analysis restricted to men >30 years of age, significant differences in mean T concentration were evident among never-users and current-users (2.55 ng/mL vs 2.60 ng/mL, p = 0.003). Significant differences were also seen with increasing duration of use as mean T concentrations were higher among men who used marijuana regularly for >5 years. In the analysis of men 20-30 years of age, no significant differences in mean T concentration by marijuana use were seen.

Conclusion: These results suggest that regular use and current use of marijuana are associated with higher T concentrations among U.S. men, particularly men > 30 years of age. As nonseminomas are more common in younger men than in older men, the results may indicate that the association between marijuana use and nonseminoma is not due to an effect of marijuana on circulating T concentrations.

Citation Format: Katherine A. McGlynn. Marijuana use and serum testosterone concentrations among U.S. males. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1756.
Abstract 1757: Male pattern baldness and risk of incident skin cancer in a cohort of men
Authors: Li Wen-Qing , Cho Eunyoung , Han Jiali , Weinstock Martin , Qureshi Abrar
Published: July 2016

Background: Male pattern baldness (androgenic alopecia) has been associated with scalp skin cancer in case-control studies. A potential androgen basis of melanoma has been hypothesized and baldness has been associated with higher levels of androgens. We examined the association between male pattern baldness and risk of skin cancer, including melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) in a prospective cohort study.

Methods: We included 36,032 participants from the Health Professionals’ Follow-up Study. In 1992, participants reported their status of male-pattern baldness at age 45 years by choosing from five crown-view pictograms based on Norwood's classification. Diagnosis of skin cancers was reported in the self-reported questionnaires biennially and report on melanoma and SCC was pathologically confirmed. Cox proportional hazard models were used to compute the hazard ratios (HR) and 95% confidence intervals (CI).

Results: We identified 327 cases of melanoma, 1324 cases of SCC, and 8438 cases of BCC during the follow-up. Male-pattern baldness at age 45 was not associated with risk of incident melanoma, but was significantly associated with increased risk of both SCC and BCC. The multivariate-adjusted HR (95% CI) for the highest category of baldness (frontal plus severe vertex baldness) was 1.33 (1.06-1.68) for SCC (Ptrend = 0.001) and 1.23 (1.12-1.35) for BCC (Ptrend<0.0001), compared with no baldness. Analyses by body sites of tumors found significant associations between frontal plus moderate to severe vertex baldness and risk of melanoma (HR = 1.83, 95% CI: 1.01-3.34) and SCC (HR = 1.30, 95% CI: 1.02-1.66) at head and neck. The associations were particularly stronger for scalp melanoma (HR = 7.15, 95% CI: 1.29-39.42) and scalp SCC (HR = 7.09, 95% CI: 3.84-13.08), but not for non-scalp head and neck sites.

Conclusion: Male pattern baldness was positively associated with increased risk of skin cancer. The associations may only exist for skin cancer at head and neck, particularly those occurring at scalp.

Citation Format: Wen-Qing Li, Eunyoung Cho, Jiali Han, Martin Weinstock, Abrar Qureshi. Male pattern baldness and risk of incident skin cancer in a cohort of men. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1757.
Abstract 1778: A comparison study of the disparities of cervical cancer excess mortality between Black and Caucasian women in Alabama and the US
Authors: Abdalla Ehsan M.
Published: July 2016

Background: The main purpose of this study was to assess the disparity of cervical cancer (CerCancer) mortality rates change through time between Black and Caucasian women residing in Alabama and the US.

Methods: The CerCancer behavioral risk factors and utilization of screening tests data were obtained from CDC's Behavioral Risk Factor Surveillance System (BRFSS) database. Baseline data and target objectives of utilization of CerCancer screening and mortality rates were obtained from Healthy People 2020. The CerCancer mortality rates data were obtained from the Surveillance, Epidemiology, and End Results (SEER). Mortality rates, percentage difference, percentage change and annual percentage change for trends were calculated and compared with the US baseline. Data were stratified by age, gender, race, and geography, using SEER*Stat version 8.4.1 in conjunction with Linear Trendlines analysis to model the racial changes of CerCancer mortality rates through time in Alabama and the US.

Results: Our results depicted in general, that although Blacks had higher CerCancer mortality rates at all times, a decreasing trend in CerCancer mortality rates was noted for both races. However, the degree of disparities in mortality rates fluctuated over time and differed by age. In Alabama, Blacks aged 65 years and older have not experienced significant decline in CerCancer mortality rates in recent years, despite a high screening rate compared to Whites. In contrast, between 2002 and 2012, Whites in Alabama and the US made a significant progress toward the Healthy People 2020 goal.

Conclusions: Conclusively in Alabama, a disparity still exists for the high CerCancer mortality rates in Blacks despite the higher rates of screening for CerCaner as would otherwise be expected. Additionally, the state has not yet achieved the Healthy People 2020 goal. Thus, although the gap in mortality rates in Alabama has narrowed, however the disparity remains, but if the dismal narrowing is sustained, it will reduce the racial disparities in CerCancer mortality though at a very slow rate. Therefore, Public health officials should monitor progress toward reduction and/or elimination of these disparities.

Citation Format: Ehsan M. Abdalla. A comparison study of the disparities of cervical cancer excess mortality between Black and Caucasian women in Alabama and the US. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1778.
Abstract 180: Identification and characterization of ATM substrates in mitosis
Authors: Boohaker Rebecca J. , Zeng Qinghua , Xu Bo
Published: July 2016

The Ataxia-Telangiectasia Mutated (ATM) Kinase, mutation of which is responsible for the autosomal recessive disorder Ataxia-Telangiectasia, is an essential element for cells to deal with DNA double-strand breaks. In the absence of DNA damage, it has also been recognized that ATM has a role in optimizing the spindle assembly checkpoint during mitosis. In the process, ATM is activated at a lower level (compared to the DNA damage response) which requires phosphorylation by the Aurora-B kinase. Known ATM targets in mitosis include kinetochore proteins Bub1 and Mad1. However, it has become clear that ATM-mediated phosphorylation in mitosis is distinct from that in the DNA damage response. Therefore, we performed an unbiased assay to identify ATM substrates in mitosis in order to study the functional significance of mitotic ATM activation. To achieve our goal, we utilized a stable isotope labeling by amino acid (SILAC) /Peptide IP with phosphor-specific SQ/TQ antibodies and mass spectrometry (MS). About 18 proteins were identified as substrates of mitotically activated ATM in the assay. We then conducted bioinformatic analyses for the identified proteins using PANTHER and Ingenuity programs. With many proteins having their known functions in mitosis, we found a much smaller number, but highly interconnected, pool of proteins in the ATM substrate list as compared to that of the DNA damage response. Among them, we validated several phosphorylation events using an in vitro kinase assay. Furthermore we present data to demonstrate the functional significance of ATM-mediated phosphorylation. Taken together, our data provide a comprehensive picture of how mitotically activated ATM signals to downstream targets to fine-tune the mitotic checkpoint.

Citation Format: Rebecca J. Boohaker, Qinghua Zeng, Bo Xu. Identification and characterization of ATM substrates in mitosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 180.
Abstract 1803: Breast cancer cell lines with acquired resistance to selective ERα degraders (SERDs) are dependent on PI3K signaling
Authors: Ong Christy , Daemen Anneleen , Oeh Jason , Ingalla Ellen , Arrazate Alfonzo , Nanini Michelle , Sampath Deepak , Friedman Lori , O’Brien Thomas
Published: July 2016

Estrogen positive (ER+) breast cancer accounts for the majority of all breast cancers and is primarily treated with endocrine therapy. However, even though current endocrine treatments are effective, a subset of patients inevitably become resistant to these treatments. The novel oral SERD, GDC-0810/ARN-810, is currently in Phase II clinical trials in ER+ breast cancer patients. GDC-0810 induces ERα degradation in ER+ MCF7 and T47D cells and inhibits cell proliferation. Moreover, it is also efficacious in ER+ tumor models in vivo, including in MCF7-ESR1 Y537S xenografts and in WHIM20 ESR1 mutant Y537S PDX tumors. Given that little is known about resistance mechanisms to SERDs, our aim was to understand what mechanisms may underlie resistance after continuous exposure.

We generated cell lines resistant to GDC-0810 and show that all of these lines were also cross-resistant to fulvestrant and tamoxifen. We determined that cells with acquired-resistance were more sensitive than parental cells to inhibitors of the PI3K/AKT signaling pathway. Additionally, in some resistant clones, ERα protein expression was lost, but this loss was transient and could be regained after long-term growth in the absence of SERDs. A range of approaches are being undertaken to explore the underlying mechanisms driving acquired-resistance to SERDs. These preclinical studies may inform future clinical combinations.

Citation Format: Christy Ong, Anneleen Daemen, Jason Oeh, Ellen Ingalla, Alfonzo Arrazate, Michelle Nanini, Deepak Sampath, Lori Friedman, Thomas O’Brien. Breast cancer cell lines with acquired resistance to selective ERα degraders (SERDs) are dependent on PI3K signaling. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1803.
Abstract 185: Role of phosphorylation in Lmtk3 activation and its contribution in breast cancer progression
Authors: Lucchiari Giulia , Zhang Hua , Nunes Joao , Xu Yichen , Grothey Arnhild , Stebbing Justin , Giamas Georgios
Published: July 2016

LMTK3 is an oncogenic receptor tyrosine kinase implicated in various types of cancer including breast, lung, gastric and colorectal. We have already demonstrated the contribution of LMTK3 in invasion, migration and transcriptional regulation as well as its involvement in endocrine resistance in breast cancer. Despite the significant progress in understanding the role of LMTK3 in human tumourogenesis, the signalling pathways implicated in LMTK3 regulation still remain to be elucidated.

Protein phosphorylation play an essential role in regulating intracellular signal transduction pathways involving almost every aspect of cell activity. In silico phosphoproteomic analysis predicted several potential LMTK3 phosphorylation sites targeted by different kinases including Cyclin-dependent kinase 5 (CDK5), a cytoplasmic proline-directed serine/threonine kinase that is commonly overexpressed in many solid tumours. Interestingly, recent work performed by two different groups showed that CDK5 is a regulator of LMTK1 and LMTK2 in neuronal cells, resulting in axonal outgrowth and potentially influencing a number of neurophysiological processes.

By performing a variety of molecular/cellular and biochemical experiments we confirmed the ability of CDK5 to phosphorylate LMTK3 in vitro and identified its exact phosphorylation sites. Moreover, we investigated the consequences of CDK5 phosphorylation on various LMTK3 processes, amongst which its stability, sub-cellular localization, its ability to interact with chromatin and others. In addition, the clinical correlation of CDK5 and LMTK3 expression in cell lines and patients’ samples were assessed. In aggregate, we describe a new cellular pathway encompassing CDK5 and LMTK3 that results in breast cancer tumour progression.

Our data will be presented.

Citation Format: Giulia Lucchiari, Hua Zhang, Joao Nunes, Yichen Xu, Arnhild Grothey, Justin Stebbing, Georgios Giamas. Role of phosphorylation in Lmtk3 activation and its contribution in breast cancer progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 185.
Abstract 1850: Transcription factor E2F3 up-regulates the expression of Gadd45b gene in the mouse liver
Authors: Kim Jung-Hwan , Gonzalez Frank J.
Published: July 2016

Growth arrest and DNA damage-inducible beta (GADD45b) plays an important role in many intracellular events, such as cell survival- and cell death-related signaling. In normal condition, Gadd45b is suppressed by the negative regulator, such as STAT3, however, when it induced by the PPARa agonist, Wy-14,643. Thus, we investigated the positive regulator of Gadd45b. Based on the Gadd45b-reporter assay, we assumed that E2Fs could regulate the Gadd45b. As results, E2F3 mRNA was induced only in the liver of Wy-14,643-treated mice. In addition, deletion of E2Fs consensus sequence in the Gadd45b reporter gene showed significant decrease of luciferase activity. Furthermore, overexpression of E2F3 significantly increased the Gadd45b-luciferase activity and this was inhibited by the siE2F3 in the Hepa1c1c7 cells. Taken together, E2F3 may play a pivotal role in the Gadd45b induction as a positive regulator.

Citation Format: Jung-Hwan Kim, Frank J. Gonzalez. Transcription factor E2F3 up-regulates the expression of Gadd45b gene in the mouse liver. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1850.
Abstract 1868: Glycodelin-producing endometrial adenocarcinoma cells are resistant to TGFβ
Authors: Hautala Laura , Koistinen Hannu
Published: July 2016

Glycodelin is a secreted glycoprotein belonging to lipocalin protein family. It is expressed mainly in reproductive and glandular tissues. Glycodlin is involved in the regulation of reproductive and immune systems and it drives epithelial differentiation. In endometrium, the expression of glycodelin is abundant in secretory phase of the menstrual cycle, while in proliferative phase it is not expressed. Most studies agree that glycodelin is not expressed in endometrial cancer. To study the effects of glycodelin in endometrial cancer cells, we have made stable glycodelin-producing HEC-1B endometrial adenocarcinoma cells. Previously, we have shown that glycodelin differentiated HEC-1B cells towards less malignant phenotype and the cells formed significantly smaller tumors in preclinical xenograft mice. In addition, glycodelin-producing cells were resistant to phorbol ester-stimulated migration and phenotypic differentiation, which was mediated by repressed activation of PKCδ. Here we studied the effect of TGFβ on glycodelin-induced differentiation of the HEC-1B cells.

Glycodelin-producing and control cells were plated on Matrigel and grown with or without TGFβ. The media was changed every second day and the cells were monitored up to one week. For Western blot analysis the cells were grown on Matrigel and TGFβ was added for 0-2h, after which the cells were detached from Matrigel and lysed.

TGFβ induced control cells to form net-like structures, similar to those found after phorbol ester exposure. However, the glycodelin-producing cells remained unresponsive. PKCδ siRNA and PKCδ inhibitor Rottlerin inhibited the effects of TGFβ. Western blot analysis showed equal phosphorylation levels of SMAD2 in glycodelin-transfected and control cells. In contrast, PKCδ and ERK1/2 were differently phosphorylated, indicating the involvement of MAPK-pathway in the TGFβ-induced changes of the control cells.

Endometrial cancer is the most common cancer of the female reproductive tract in developed countries. However, the molecular mechanisms affecting the pathogenesis of the disease are still poorly understood. It has been suggested that TGFβ is involved in carcinogenesis of endometrial cancer. Therefore, our results showing that glycodelin-producing HEC-1B endometrial adenocarcinoma cells are resistant to the effects of TGFβ, due to the repressed PKCδ phosphorylation, may be important to understand the pathogenic mechanisms of endometrial cancer.

Citation Format: Laura Hautala, Hannu Koistinen. Glycodelin-producing endometrial adenocarcinoma cells are resistant to TGFβ. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1868.
Abstract 1869: Dislodgement of K-Ras from plasma membranes, induction of apoptosis and tumor regression by PCAIs, a novel class of polyisoprenylated small molecules
Authors: AMISSAH FELIX , NTANTIE ELIZABETH , POKU ROSEMARY A. , NKEMBO AUGUSTINE T. , SALAKO OLUFISAYO O. , FLORES-ROZAS HERNAN , LAMANGO NAZARIUS S.
Published: July 2016

Although mutation-induced dysregulation of Ras signaling constitutes the biochemical change that drives some of the most difficult-to-manage cancers, directly targeting the constitutively active mutant Ras GTPases has not resulted in clinically useful drugs. Therefore, modulating Ras activity for targeted treatment of cancer remains an urgent healthcare need. In the current study, we investigated a novel class of compounds, the polyisoprenylated cysteinyl amide inhibitors (PCAIs), for their anticancer molecular mechanisms using the NSCLC cell panel with K-Ras and/or other mutant genes. Treatment of the lung cancer cells with PCAIs, NSL-RD-035, NSL-BA-036, NSL-BA-040, NSL-BA-055 and NSL-BA-040 resulted in concentration-dependent cell death in both K-Ras mutant (A549 and NCI-H1573), N-Ras mutant (NCI-H1299) and other (NCI-H661, NCI-H460, NCI-H1975, NCI-H1563) NSCLC cells. The PCAIs at sub- to low micromolar 1.0 -10 μM concentrations induced the degeneration of 3D spheroid cultures, inhibited, clonogenic cell growth, and induced marked apoptosis and cell cycle arrest, together with a significant increase in active caspase 3 (p<0.001). NSL-BA-040 at 5 μM prominently dislodged YFP-tagged K-Ras, but not H-Ras and N-Ras from the plasma membranes of transfected A549 and NCI-H661 cells. NSL-RD-035 attenuated the tumor growth of A549 cells in xenografted athymic mice in vivo. Taken together, PCAIs likely suppress NSCLC cell growth by disrupting growth signaling through the dislodgement of K-Ras the plasma membrane.

Citation Format: FELIX AMISSAH, ELIZABETH NTANTIE, ROSEMARY A. POKU, AUGUSTINE T. NKEMBO, OLUFISAYO O. SALAKO, HERNAN FLORES-ROZAS, NAZARIUS S. LAMANGO. Dislodgement of K-Ras from plasma membranes, induction of apoptosis and tumor regression by PCAIs, a novel class of polyisoprenylated small molecules. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1869.
Abstract 1874: Oncogenic EGFR signaling inhibits the Spred1-NF1 interaction to sustain constitutive Ras signaling
Authors: Markegard Evan , Mercado Ellen L. , Galeas Jacqueline , Trinidad Marena I. , Urisman Anatoly , McCormick. Frank
Published: July 2016

Spred proteins negatively regulate Ras/MAPK signaling following mitogen stimulation. Inhibition of Ras primary occurs through Spreds ability to bind and localize NF1, a RasGAP and major tumor suppressor, to the plasma membrane. Loss-of-function Spred1 and NF1 mutations occur across multiple cancer types including melanoma, non-small cell lung carcinoma, stomach carcinoma, and uterine carcinosarcoma. Here we demonstrate that oncogenic EGFR signaling disrupts Spred1-NF1 binding. Mass spectrometry was performed on cells overexpressing EGFRL858R to identify potential phosphorylation sites on Spred1 and NF1 that could disrupt Spred1-NF1 binding by steric hindrance. A serine phosphorylation site on Spred1 was identified in which a phosphomimetic and phosphodeficient mutant decreased or increased Spred1-NF1 binding, respectively. Therefore, phosphorylation of Spred1 at this site by a serine kinase downstream of oncogenic EGFR may disrupt Spred1-NF1 binding. Our findings provide one potential mechanism by which oncogenic EGFR signaling disrupts negative feedback to allow for constitutive Ras signaling. Furthermore, this work may elucidate a novel kinase therapeutic target for restoring NF1 mediated inhibition of Ras.

Citation Format: Evan Markegard, Ellen L. Mercado, Jacqueline Galeas, Marena I. Trinidad, Anatoly Urisman, Frank McCormick. Oncogenic EGFR signaling inhibits the Spred1-NF1 interaction to sustain constitutive Ras signaling. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1874.
Abstract 1890: IKBKE is a substrate of EGFR and a therapeutic target in NSCLCs with activating mutations of EGFR
Authors: Challa Sridevi , Guo Jian-Ping , Xu Cheng-xiong , Li Yajuan , Kim Donghwa , Cress Douglas , Haura Eric , Coppola Domenico , Cheng Jin
Published: July 2016

EGFR is one of key driver pathways of non-small cell lung cancer (NSCLC). EGFR inhibitors have shown significant response in patients with EGFR mutation. However, patients develop resistance in short period of time, which results from secondary EGFRT790M mutation and other mechanisms. Here, we demonstrated that activating mutations of EGFR significantly activated IKBKE, an IκB kinase family member previously shown to activate Akt and NF-κB pathways. Furthermore, we showed that EGFR directly interacts with and phosphorylates IKBKE on tyrosine 153 and tyrosine 179 residues. IKBKE-Y153F/179-F, a mutant that could not be phosphorylated by EGFR, largely reduced its kinase activity and failed to activate Akt and NF-κB as well as inhibited EGFR signaling. Furthermore, phospho-IKBKE-Y153 correlated with EGFR activation in NSCLC patients. Notably, depletion of IKBKE by either small molecule inhibitor amlexanox or shRNA selectively inhibited cell viability in NSCLC cells with EGFR mutations. Moreover, we observed that inhibition of IKBKE led to feedback activation of the MAPK pathway. Combination of amlexanox with MEK inhibitor AZD6244 significantly inhibits cell survival and tumor growth in NSCLC cells driven by activating EGFR mutations including EGFRT790M. Thus, our findings not only identify IKBKE as a direct downstream target of EGFR but also provide a potential therapeutic strategy for EGFR-TKI resistant NSCLC driven by secondary EGFR mutation.

Citation Format: Sridevi Challa, Jian-Ping Guo, Cheng-xiong Xu, Yajuan Li, Donghwa Kim, Douglas Cress, Eric Haura, Domenico Coppola, Jin Cheng. IKBKE is a substrate of EGFR and a therapeutic target in NSCLCs with activating mutations of EGFR. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1890.
Abstract 1895: Metastasis-associated protein 1 drives prostate cancer progression and metastasis through regulation of onco-epimicroRNAs
Authors: Dhar Swati , Butt Nasir A. , Kumar Avinash , Zhang Xu , Levenson Anait S.
Published: July 2016

Our recent studies in prostate-specific tumor suppressor Pten gene compromised transgenic mice, revealed a strategic role for Metastasis Associated protein 1 (MTA1), a component of the chromatin remodeling NuRD complex and a key regulator of metastasis, in the progression of prostate cancer. Chromatin Immunoprecipitation Sequencing (ChIP-Seq) analyses from the mouse prostate tissues showed MTA1 occupancy of several potential oncogenic miRNA target promoters including miR-22. Retrospective investigation of microRNA microarray experiments revealed downregulation of these candidate miRNAs in LNCaP cells silenced for MTA1 expression (shMTA1). Real time PCR evaluation of shMTA1 cell lines, LNCaP, DU145 and PC3M attested the microarray findings. Using miRNA-mRNA target prediction algorithms, miRanda, miRDB and Targetscan, E-cadherin (CDH1) was identified as a potential target with high context score for miR-22. Interestingly, E-cadherin, which has a pivotal role in preventing Epithelial to Mesenchymal Transition (EMT) of tumor cells was also identified as a MTA1 target gene by ChIP-Seq analysis. Further, qRT-PCR and western blot experiments validated that MTA1 levels had an inverse correlation with E-cadherin expression in these cell lines. Transient transfection of miR-22 mimics diminished E-cadherin levels while this expression was restored by miR-22 sponge inhibitors showing that miR-22 can control E-cadherin expression. Ongoing experiments aim to address the direct targeting of E-cadherin 3′UTR by miR-22 using Dual-Glo luciferase reporter assay and the functional consequences of miR-22 promoter regulation by MTA1 utilizing chromatin and RNA immunoprecipitation assays. Our studies reveal a novel and previously unrecognized role for MTA1-mediated miR-22 regulation of E-cadherin.

Citation Format: Swati Dhar, Nasir A. Butt, Avinash Kumar, Xu Zhang, Anait S. Levenson. Metastasis-associated protein 1 drives prostate cancer progression and metastasis through regulation of onco-epimicroRNAs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1895.
Abstract 1902: Downregulation of MYC by miR-3189-3p in glioblastoma
Authors: Jeansonne Duane , Reiss Krzysztof , Peruzzi Francesca
Published: July 2016

Glioblastoma is a devastating malignancy with a median survival of approximately 15 months. This aggressive tumor originates from the glial cells and accounts for nearly 50% of adult brain tumors. Glioblastomas are characterized by rapid proliferation and resistance to standard treatment of surgery, temazolamide and radiation therapy. MicroRNAs are short single-stranded non-coding RNAs that regulate gene expression in both normal and pathological conditions. We have previously found downregulation of miR-3189-3p in glioblastomas and astrocytomas. Using in vitro models, we demonstrated that ectopic expression of this miRNA inhibited glioblastoma cell growth and migration through downregulation of the splicing factor SF3B2 and the guanine nucleotide exchange factor p63RhoGEF, respectively. The miR-3189-3p-mediated inhibition of glioblastoma growth in vivo further confirmed the anti-cancer activity of this microRNA.

Given the strong biological effect of this miRNA on glioblastoma cells, we sought to investigate the implication of other gene targets in miR-3189-3p-mediated effects. The elevated expression of MYC oncogene is found in a variety of cancer types, including glioblastoma. Here, we demonstrated that overexpression of miR-3189-3p results in downregulation of MYC. Since this gene is not a predicted target for miR-3189-3p, we hypothesized that this modulation of MYC expression is mediated through the translational repressor, TIA1 cytotoxic granule-associated RNA binding protein-like 1 (TIAL1, also called TIAR). We tested the levels of TIAR in cells treated with miR-3189-3p and found no changes in TIAR expression. However, the downregulation of MYC was dependent on TIAR expression, as determined through siRNA-mediated downregulation of TIAR. Further studies are needed to elucidate molecular mechanisms of TIAR-dependent downregulation of MYC by miR-3189-3p. In addition, a putative binding site for miR-3189-3p is located within the open reading frame of MYC; therefore, studies will be performed to determine whether miR-3189-3p downregulates MYC by directly binding outside the 3’-UTR of this transcript.

Citation Format: Duane Jeansonne, Krzysztof Reiss, Francesca Peruzzi. Downregulation of MYC by miR-3189-3p in glioblastoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1902.
Abstract 1906: Inhibition of miR-186 and repression of aggressive prostate cancer phenotype using a metastatic cell model
Authors: Jones Dominique Z. , Schmidt M. Lee , Hobbing Katharine R. , Clark Geoffrey , Kidd LaCreis R.
Published: July 2016

MicroRNA (miR) dysregulation alters the expression of cancer related genes and contributes to disease states in many cancers. For example, ectopic miR-186 expression leads to enhanced cell proliferation and migration in pancreatic cancer. However, the role of miR-186 in prostate cancer (PCa) remains unclear. Previously, we observed significant upregulation of miR-186-5p in PCa patient serum (stage III/IV) compared to controls. Furthermore, miR-186 was significantly up-regulated in metastatic PCa (PC-3) compared to normal prostate epithelial cells (RWPE1). We hypothesized miR-186 inhibition will reduce aggressive PCa in vitro.

Consequently, miR-186 was transiently and stably inhibited in PC-3 cells. Cell proliferation and colony formation were evaluated for 7 and 21 days via Trypan Blue exclusion and soft agar assays. Aberrant gene expression was evaluated in transfected cells to identify miR-186 targets. Candidate miR-186 targets were selected using published reports on ‘miR-186 and cancer’, availability of robust antibodies, and statistical filtering (false discovery ≥0.05 and ±1.2 fold change).

Mir-186 inhibition in PC-3 cells significantly repressed proliferation and colony formation by 34-64%. Following miR-186 inhibition in PC-3 cells, 2,343 identified mRNA targets were differentially expressed compared to scramble controls (p < 0.05). The target list was reduced to 11 up-regulated candidates. Predicted miR-186 targets are undergoing validation via qRT-PCR, western blots, and luciferase reporter assays. In addition, other studies are in progress to evaluate the impact of miR-186 on cellular proliferation, migration and invasion. Such efforts may lead to the identification of novel biomarkers to improve detection and clinical management strategies for aggressive PCa.

Citation Format: Dominique Z. Jones, M. Lee Schmidt, Katharine R. Hobbing, Geoffrey Clark, LaCreis R. Kidd. Inhibition of miR-186 and repression of aggressive prostate cancer phenotype using a metastatic cell model. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1906.