bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4478: The tumor suppressive function of HPP1 is mediated by its EGF-like domain
Authors: Elahi Abul , Ajidahun Abidemi , Hendrick Leah , Husain S. Mazher , Getun Irina , Becker Andreas , Glazer Evan S. , Shibata David 
Published: August 2018

Abstract
Introduction:
HPP1 is a putative tumor suppressor gene that has had significant interest as a potential serum- and stool-based biomarker in colorectal cancer. It is an Epidermal Growth Factor (EGF)-like ligand that we have previously demonstrated to mediate its effects via an erbB4-JAK-STAT signaling cascade. HPP1 is a secreted transmembrane protein comprised of two follistatin modules, a cytosolic tail with a potential G - protein-activating motif and an EGF-like domain which differs from EGF by replacement of arginine (R) by a histidine (H) residue at the critical 299 position. The exact component of HPP1 responsible for its biologic function has yet to be elucidated. We sought to examine the specific role of the EGF-like domain and the contribution of the H299R alteration.
Methods:
Synthetic wild-type (WT; H299) and mutant (R299) peptides were prepared at our crystallographic core facility. The change in amino acid did not alter the predicted 3D structure of the peptide. A total of 50ng/ml of each peptide per well (6-well plate) were used to treat the HPP1 non-expressing HCT116 colon cancer cell line. Cells were starved for 24 hours with a peptide exposure time of 7 minutes. Using immunoblot analyses, we examined alterations in the expression and activation status of erbB4, and STAT family proteins.
Results:
Delivery of the WT peptide into the HCT116 cell line resulted in increased activation/phosphorylation of erbB4, STAT1 and STAT2 with a concomitant downregulation of STAT3 activation as compared to controls. These findings are identical to the signaling profile that we have previously described for full length HPP1 and required for its tumor suppressive activity. The mutant peptide did not result in any change in the phosphorylation status of erbB4, STAT1 or STAT2 but was associated with an increase in STAT3 activation as compared to controls.
Conclusion:
The EGF-like domain of HPP1 is the key moiety responsible for triggering its tumor suppressive erbB -STAT signaling cascade. Furthermore, the histidine residue at position 299 is critical and differentiates it from the oncogenic function of EGF. Our findings may have implications for the further understanding of EGF-related signaling in cancer progression.
Citation Format: Abul Elahi, Abidemi Ajidahun, Leah Hendrick, S. Mazher Husain, Irina Getun, Andreas Becker, Evan S. Glazer, David Shibata. The tumor suppressive function of HPP1 is mediated by its EGF-like domain [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4478.
Abstract 4493: p190B RhoGAP modifies growth factor signaling in breast cancer in a non-cell autonomous manner
Authors: Castro Eduardo , Preston Aaron , Quinlan Mykal , McHenry Peter 
Published: August 2018

Abstract
Estrogen mediates the growth and differentiation of breast epithelial cells and plays an important role in breast cancer progression. The upregulation of estrogen receptors has been linked to p190B RhoGAP in vivo. p190B regulates the activity of several Rho GTPases in vitro. To better understand the molecular mechanism of p190B's role in tumor progression, we sought to develop a cell culture model that would recapitulate the effects of p190B on various growth factor signaling pathways. Protein expression of p190B was knocked down using siRNA in MCF-7 breast cancer cells cultured in the absence of steroid hormones. Upon stimulation with estrogen, cell proliferation did not significantly differ between MCF-7 cells expressing reduced p190B and those expressing normal levels of p190B, suggesting that the effects of p190B on estrogen receptor expression are not cell autonomous and that additional components of the tumor microenvironment are required to recapitulate the in vivo findings.
Citation Format: Eduardo Castro, Aaron Preston, Mykal Quinlan, Peter McHenry. p190B RhoGAP modifies growth factor signaling in breast cancer in a non-cell autonomous manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4493.
Abstract 4495: A CD10+GPR77+ subset of cancer-associated fibroblasts promotes cancer formation and chemoresistance by sustaining cancer stem cells
Authors: Song Erwei 
Published: August 2018

Abstract
Carcinoma-associated fibroblasts (CAFs) are an abundant and heterogeneous population of stromal cells in the tumor microenvironment critically involved in cancer progression. However, the lack of effective tools to isolate CAF subsets has prevented a comprehensive functional characterization of CAFs as well as their therapeutic potentials. Here, we demonstrate that two cell-surface molecules, CD10 and GPR77, specifically define a new CAF subset correlated with chemoresistance and poor survival in multiple cohorts of breast and lung cancer patients. CD10+GPR77+ CAFs promote tumor formation and chemoresistance by providing a survival niche for the cancer stem cells (CSCs). Mechanistically the functions of the CAF subset are driven by persistent NF-κB activation via p65 phosphorylation and acetylation, which is maintained by complement signaling via GPR77, a C5a receptor. Furthermore, CD10+GPR77+ CAFs are crucial for the successful engraftment of patient-derived xenografts (PDXs) in vivo and targeting these CAFs with a neutralizing anti-GPR77 antibody abolishes tumor formation and restores tumor chemosensitivity. This discovery represents the first time a functional CAF subset is identified using specific surface markers, which will greatly facilitate future investigations of the tumor microenvironment and suggests that targeting the CD10+GPR77+ CAF subset could be an effective therapeutic strategy against CSCs-driven solid tumors.
Citation Format: Erwei Song. A CD10+GPR77+ subset of cancer-associated fibroblasts promotes cancer formation and chemoresistance by sustaining cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4495.
Abstract 4504: Functional roles of KRT6-KRT14 fusion variant 7 in desmosome remodeling and cell spreading/migration
Authors: Sheu Jim J. , Kuo Brian Y. , Wu Chia-Cheng , Yang Jacky , Chen Chih-Mei 
Published: August 2018

Abstract
Keratins are intermediate filament (IF) proteins with major functions in controlling/maintaining cell morphology and stiffness. Recent studies indicated possible involvement of keratin IFs in cancer developments. In our previous study, we have identified the existence of keratin fusions between KRT6 and KRT14 genes in oral squamous cell carcinoma (OSCC), and patients with the history of chewing betel nut showed higher frequency to harbor such fusions in their tumor tissues. In this study, we studied bio-functional roles of a major keratin fusion isotype K6-K14/V7, which correlated with bigger tumor size, in cell migration and invasion. We established a tet-off inducible gene expression system in OSCC cells. After gene being turned on, K6-K14/V7 formed a peripheral-dominant network that subsequently up-regulated genes related to actin filament remodeling via mechano-transduction. Actin-associated protrusion at cell leading edge was also increased by K6-K14/V7 to enhance cell migration and invasion. Interestingly, the desmosome junction was found to be dramatically reduced, leading to loss of cell-cell contact and stemness formation via epithelial-mesenchymal transition (EMT). The K6-K14/V7-expressing cells showed reduced drug sensitivity toward 5-FU and cisplatin treatment, and formed more colonies in vitro and bigger tumors in vivo. This study uncovers new functions/definitions for keratin IF in cancer development, Mechanisms revealed by this study can help us to design new strategies for new drug development and clinical treatments.
Citation Format: Jim J. Sheu, Brian Y. Kuo, Chia-Cheng Wu, Jacky Yang, Chih-Mei Chen. Functional roles of KRT6-KRT14 fusion variant 7 in desmosome remodeling and cell spreading/migration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4504.
Abstract 4507: C-X-C motif ligand 1 from melanoma cells downregulates the invasion of their metastatic melanoma cells
Authors: Hatano Takaharu , Yashiro Masakazu , Motomura Hisashi , Fujikawa Heishiro , Maeda Shusaku 
Published: August 2018

Abstract
[Introduction]The prognosis of patients with malignant melanoma is extremely poor because of the frequent metastasis. We have occasionally experienced the clinical cases that malignant melanoma patients rapidly developed distant metastases after the surgical resection of primary cancer lesion. These cases suggested that a primary tumor may control a metastatic tumor. We hypothesized that primary melanoma cells might produce a factor(s) which regulate the progression of metastatic melanoma cells. We reported that the conditioned medium from B16 cells significantly (p=0.02) suppressed the invasion ability of B16/BL6 cells, which is a subline of B16 melanoma and shows high metastatic potential to lung at the previous meeting. Then we investigated the growth and invasion interaction between primary malignant melanoma cells and high metastatic melanoma cells at the molecular level. [Materials and methods]We used two mouse melanoma cell lines, B16 and B16/BL6, that latter of which is a subline of B16 melanoma and shows high metastatic potential to lung. We investigated the interaction between the parent B16 cells and daughter B16/BL6 cells by invasion assay, cell morphology, cytokine array, RT-PCR, and gelatin-zymography. [Results]The conditioned medium (CM) from B16 cells significantly (p=0.02) inhibited the invasion ability of B16/BL6 cells. The morphology of the B16/BL6 cells was changed by the CM from bipolar in B16 cells to a multipolar shape. The B16 cells produced high levels of C-X-C motif ligand 1 (CXCL1), CXCL10, and M-CSF compared to the B16/BL6 cells. CXCL1 significantly (p=0.01) decreased the invasion ability of B16/BL6 cells, but CXCL10 and M-CSF did not. The invasion-inhibitory activity of the CM from B16 cells was significantly (p=0.046) suppressed following the addition of a neutralizing anti-CXCL1 antibody. The CM of B16 and CXCL1 increased the E-cadherin mRNA level and MMP2 activity of B16/BL6 cells. [Conclusion]Primary melanoma cells might down-regulate the invasion activity of metastatic melanoma cells through CXCL1 signaling.
Citation Format: Takaharu Hatano, Masakazu Yashiro, Hisashi Motomura, Heishiro Fujikawa, Shusaku Maeda. C-X-C motif ligand 1 from melanoma cells downregulates the invasion of their metastatic melanoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4507.
Abstract 4510: SHH and GATA interplay: A potential therapeutic target for prostate cancer
Authors: Morsi Rami Z. , Kheir Wassim Abou , El-Khatib Layal , Msheik Hiba , Daoud Georges 
Published: August 2018

Abstract
Background: Prostate cancer is the second leading cause of cancer deaths in males worldwide. Typically, prostate cancer cells depend on androgens, and many therapeutic strategies target receptors involved in androgen regulation. However, certain castration-resistant tumors of the prostate are resistant to androgen deprivation therapies. Moreover, advanced-stage prostate tumors can proliferate uncontrollably either due to androgens or due to alteration in other signaling pathways. For instance, the activity of the sonic hedgehog (SHH) pathway, which usually decreases during post-natal development, is increased during prostate cancer progression. Of interest, a recent study reported a novel role for GATA transcription factors as potential repressors of SHH signaling. Based on the above-mentioned findings, we hypothesize that the balance between GATA and SHH pathways is perturbed in prostate cancer leading to overactivation of SHH pathways and its downstream effector proteins. Methods: We screened human prostate cancer cell lines, DU145, 22Rv1, and PC3, as well as a human immortalized normal prostate epithelial cell line, RWPE-1, for baseline levels of expression of SHH downstream effector proteins via real-time PCR using specific primers. Subsequently, we treated the cell lines with bone morphogenetic protein 4 (BMP4)-conditioned media in order to induce the expression of GATA transcription factors, and then we measured the levels of expression for each of the SHH pathway effector proteins by real-time PCR. Results: We demonstrated that GATA can interfere with the expression of SHH and its effector proteins in the human prostate cancer cell lines. Upon treatment with BMP4, we noted that there was a decrease in expression of Gli1, Gli2, and Gli3, downstream effectors of SHH, suggesting an anti-proliferative response. Additionally, Patched1 expression was also attenuated after treatment with BMP4. Similarly, Sox9 expression was also abrogated. Conclusion: Our results demonstrate that GATA transcription factors can act as potential repressors of the SHH pathway in the context of prostate cancer in vitro by interfering with the expression of SHH downstream effector proteins.
Citation Format: Rami Z. Morsi, Wassim Abou Kheir, Layal El-Khatib, Hiba Msheik, Georges Daoud. SHH and GATA interplay: A potential therapeutic target for prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4510.
Abstract 4511: The role of Wnt5a signaling pathway in epithelial ovarian cancer progression
Authors: Asem Marwa , Young Allison , Oyama Carlysa , Burkhalter Rebecca , Buechler Steven , Miller Daniel , Stack Sharon 
Published: August 2018

Abstract
Ovarian cancer (OvCa) is the most fatal gynecologic malignancy and the 5th leading cause of cancer death among U.S. women. The majority of women with OvCa (75%) have a very low survival rate (30%), as OvCa is usually diagnosed in late stages after development of intraperitoneal metastasis. Thus, it is indispensable to understand the molecular mechanisms that contribute to OvCa metastatic success, in order to design effective treatment strategies to improve the overall survival of women with OvCa. Wnt5a is a noncanonical Wnt ligand that binds to several cell membrane receptors and activates many downstream signaling pathways that are fundamental for normal developmental processes during embryogenesis. In the past decade, the aberrant activation or inhibition of Wnt5a signaling is emerging as an important event in cancer progression, exerting both oncogenic and tumor-suppressive effects. The role of Wnt5a in OvCa is controversial, as studies report conflicting data. In addition, mechanistic data regarding the contribution of Wnt5a to OvCa progression are largely unavailable. The main aim of this research is to obtain a molecular-level understanding of Wnt5a signaling in OvCa and to investigate its potential roles in influencing OvCa metastatic success. Our data show Wnt5a is prevalent in ascites samples from women in different stages with OvCa, suggesting a role for Wnt5a in promoting disease progression. Data obtained from TCGA (n=583) show high expression of Wnt5a in primary ovarian tumors. Furthermore, Wnt5a enhanced OvCa cells adhesion, migration and invasion in a panel of organotypic and ex vivo functional assays. This was combined with striking morphologic changes characteristic of an invasive phenotype in OvCa cells treated with recombinant Wnt5a protein and formation of tunneling nanotubes (TNT). Overall, our data suggest that Wnt5a plays an oncogenic role in epithelial ovarian cancer cells. More experiments exploring Wnt5a activated pathways and effects in epithelial ovarian cancer cells are under way.
Citation Format: Marwa Asem, Allison Young, Carlysa Oyama, Rebecca Burkhalter, Steven Buechler, Daniel Miller, Sharon Stack. The role of Wnt5a signaling pathway in epithelial ovarian cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4511.
Abstract 4516: A new MLH1 rabbit monoclonal antibody for immunohistochemical application
Authors: Cobb Sean , Pan Hongyang , Yang Qiong , Chan Jackie , Wu Julia , Law Jason , Li Aihua 
Published: August 2018

Abstract
Background: MLH1, a DNA mismatch repair gene, plays a critical role in colorectal cancer (CRC) development. Loss of nuclear MLH1 is attributed to hypermethylation of its promoter, occurring in 78% of microsatellite instability (MSI) which composes 15% of all CRC. Immunohistochemical (IHC) analysis of MLH1 in CRC is routinely performed in pathology laboratories, but remains challenging with the current selection of available MLH1 antibodies. Here we report a new MLH1 rabbit monoclonal antibody (RabMAb) developed with RabMAb® technology, designated as clone EP481.
Design: Sera collected from rabbits immunized with recombinant MLH1 protein were screened by ELISA, WB, and IHC. After fusion, antibody from a final hybridoma cell line was further characterized by extensive IHC testing using formalin-fixed paraffin-embedded human normal and tumor tissue microarrays (TMAs) comprised of 99 CRCs. EP481 performance was compared against MLH1 mouse monoclonal antibodies, G168-15, G168-728, and the current benchmark, ES05. Cases without tumor cell staining were considered negative; those also lacking stroma staining were excluded, as it could not be determined if there was germline mutation or poor tissue quality. Agreement was evaluated with Cohen's kappa.
Results: An 85 kDa MLH1 protein was detected by WB in SW480 cell lysate, but absent in the MLH1-negative cell line, HCT116. IHC analysis of EP481 was positive in normal epithelium and surrounding stroma, but negative in 10% of tumors. G168-728 showed nonspecific cytoplasmic staining and deviated from its counterparts. Concordance data (Table 1) demonstrates that EP481 is equivalent with ES05 and incongruous with G168-15.
Conclusion: The RabMAb MLH1 antibody, clone EP481, specifically labels normal cells and is absent in 10% of CRCs. This finding is consistent with both literature and the gold-standard anti-mouse clone, ES05. EP481 is a new alternative for MLH1 IHC and a promising tool to identify MSI in CRC.
Table 1. Concordance staining of MLH1 clone EP481 with clones ES05 and 168-15 on CRC TMA.ES05 +ES05 -Total168-15 +168-15 -TotalEP481 +7417566975EP481 -178268Total75883681583Cohen's kappaRatersCoefficientAgreementEP481/ES0586%ExcellentEP481/168-1545%Moderate
Citation Format: Sean Cobb, Hongyang Pan, Qiong Yang, Jackie Chan, Julia Wu, Jason Law, Aihua Li. A new MLH1 rabbit monoclonal antibody for immunohistochemical application [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4516.
Abstract 4531: Development of a companion diagnostic assay for the detection of phosphatase and tensin (PTEN) protein loss and treatment with ipatasertib in metastatic castration-resistant prostatic cancer (mCRPC)
Authors: Stephens Crystal , Harnish Erica , Bowermaster Rebecca , Djalilvand Azita , Smith Dustin , Kim Doris , Gendreau Steven , Valle Edmundo Del 
Published: August 2018

Abstract
Background: Ventana Medical Systems, Inc. is developing in collaboration with Genentech, Inc., an immunohistochemical (IHC) companion diagnostic to aid in selecting patients with metastatic castration-resistant prostate cancer (mCRPC) that may benefit from ipatasertib, an Akt inhibitor therapy. The phosphatase and tensin (PTEN) protein plays an important role in controlling cell survival and cell cycle progression as a negative regulator of the phosphoinositide 3-kinase/AKT pathway.
Methods: PTEN (SP218) rabbit monoclonal primary antibody was optimized for use with the VENTANA OptiView DAB IHC Detection Kit on the automated BenchMark ULTRA platform (PTEN (SP218) RxDx Assay). The PTEN (SP218) RxDx Assay was developed for use in formalin-fixed, paraffin-embedded tissue samples of mCRPC in a series of studies addressing sensitivity, specificity, robustness and precision. The scoring algorithm was defined using statistical analysis of clinical outcome data analysis, and the PTEN (SP218) RxDx Assay staining pattern and prevalence of PTEN loss of expression in a set of tissue samples. Inter-reader precision was established by 3 pathologists evaluating 90 mCRPC samples across the range of PTEN expression levels.
Results: The Ventana PTEN (SP218) RxDx Assay met all pre-defined acceptance criteria. mCRPC tissue samples are designated with PTEN-Loss status when ≥ 50% of viable malignant cells have no specific cytoplasmic staining with PTEN (SP218) in the presence of acceptable internal controls. Inter-reader precision in determining PTEN status resulted in agreement rates greater than 97%.
Conclusion: These results highlight the robustness and reproducibility of the Ventana PTEN (SP218) RxDx Assay. In the clinical outcome analysis, patients identified to have PTEN-loss status demonstrated clinically meaningful improvements when treated with ipatasertib. The clinical utility of the PTEN (SP218) RxDx assay will be further validated in additional patients in subsequent ipatasertib studies, including a Phase 3 study (IPATential150) beginning in 2017.
Citation Format: Crystal Stephens, Erica Harnish, Rebecca Bowermaster, Azita Djalilvand, Dustin Smith, Doris Kim, Steven Gendreau, Edmundo Del Valle. Development of a companion diagnostic assay for the detection of phosphatase and tensin (PTEN) protein loss and treatment with ipatasertib in metastatic castration-resistant prostatic cancer (mCRPC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4531.