bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3418: A NGS-based SNP array for the identification of human xenograft tumors, mouse homograft tumors, human and mouse cell lines, organoids
Authors: Chen Xiaobo , Qian Wubin , Guo Sheng , Li Henry
Published: August 2019

Transplanted tumor models, including xenograft tumors (e.g. patient derived xenograft, or PDX, human cell line derived tumors, mouse homograft (e.g. syngeneic tumors), as well as many cancer cell lines of both human and mouse origins are the key preclinical tools used in cancer researches, including drug efficacy assessment, drug target/biomarker discovery, as well as drug mechanism of actions and resistances, etc. The broad applications of these models in all different global laboratories at different times creates great risk of cross-contaminations (intra-/inter-species) as well as unintended de-identification. It is prudent to be able to track and QC tumors to ensure their authenticity by a simple and routine assays. The most common assay to identify human xenografts are Short Tandem Repeat (STR) test using multiple independently assorted STR loci. However, STR testing may suffer from several limitations, e.g. inadequate accuracy, especially for samples of kinship or close genetic background, inability to distinguish tumor of mouse origins as well as assessing mouse components in human xenografts. In addition, STR is also labor intensive, costly, low through-put, and ineffective for samples of low amount/poor quality. Single Nucleotide Polymorphisms (SNPs) based assays are increasingly used recently to replace STR testing with higher accuracy1-4. SNPs are genetic markers at single-nucleotide resolution. It is also amicable to automation, suitable for low amount/degraded samples with fragment length as short as only 60-80bp. Multiple SNPs can be simultaneously assayed by Next Generation Sequencing (NGS) technology. We developed a NGS-based SNP array for the identification of our libraries of xenografts, homografts, cell lines, etc. The assay is consisted of ~300 SNPs, 200 of which are used to authenticate different human origins, which were first constructed as unique fingerprints for every PDX from Whole-Exome Sequencing (WES) and RNAseq data, followed by that a sample is tested by the NGS-based SNP array to obtain its SNP fingerprint which is compared against all known fingerprints. The remaining 100 SNPs are used to infer gender and ethnicity, common viral infection, mouse content, mouse strain, homograft tumors, etc., as well as possible mycoplasmas contamination. Validation studies on multiple PDX models show that the array achieves near perfect results. In summary, we have established a high-throughput multi-purpose NGS-based SNP array that can be applied to the quality assurance of all the common cancer models.

Citation Format: Xiaobo Chen, Wubin Qian, Sheng Guo, Henry Li. A NGS-based SNP array for the identification of human xenograft tumors, mouse homograft tumors, human and mouse cell lines, organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3418.
Abstract 3561: MicroRNA-214 inhibits prostate cancer cell proliferation, migration, invasion and increases drug sensitivity by targeting PTK6
Authors: Cagle Patrice , Niture Suryakant , Srivastava Anvesha , Ramalinga Malathi , Rios-Colon Leslimar , Chimeh Uchechukwu , Kumar Deepak
Published: August 2019

MicroRNAs (miRNAs) are involved in numerous physiological and pathological processes and play a critical role in cancer progression and the role miRNA-214 (miR-214) in prostate cancer remains elusive. In the present study, we investigated the effect of expression of miR-214 on cell survival/migration/invasion, cell cycle regulation, and apoptosis. Differential expression of miR-214 was found between Caucasian, African American prostate cancer cells compared with normal prostate epithelial cells. Expression of miR-214 in prostate cancer cells inhibited cell proliferation and colony forming capability, and induced apoptosis. miR-214 also inhibited cell migration and 3D spheroid invasion in prostate cancer cells. Interestingly, miR-214 targets protein tyrosine kinase 6 (PTK6) and reduced PTK6 expression. The restoration of PTK6 expression significantly blocked the inhibitory effect of miR-214 on cell proliferation. Moreover, inactivation of PKT6 by ibrutinib and expression of miR-214 significantly enhanced the cell death in prostate cancer cells. Collectively the data suggest that miR-214 functions as a tumor suppressor in prostate cancer, and may become a potential therapeutic target in prostate cancer.

Citation Format: Patrice Cagle, Suryakant Niture, Anvesha Srivastava, Malathi Ramalinga, Leslimar Rios-Colon, Uchechukwu Chimeh, Deepak Kumar. MicroRNA-214 inhibits prostate cancer cell proliferation, migration, invasion and increases drug sensitivity by targeting PTK6 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3561.
Abstract 3571: Identification of a novel imatinib upregulated lncRNA family that is required for efficient cellular transformation by Abl oncogene
Authors: Chen Jilong , Wang Xuefei
Published: August 2019

Bcr-Abl oncogene is generated by a reciprocal translocation between chromosome 9 and 22 in human genome, giving Bcr-Abl protein with constitutive tyrosine kinase activity that causes chronic myeloid leukemia (CML) . Few acute lymphoblastic leukemia (ALL) patients also contain Bcr-Abl oncogene. Owing to the development of imatinib, over 90% of CML patients can be cured in recent years. However, the functional relevance of lncRNAs in Bcr-Abl-mediated leukemia remains obscure. Here, we identified a conserved, imatinib-upregulated lncRNA (IUR) family, named lncRNA-IUR37. Upregulation of lncRNA-IUR37 has been detected in both human and mouse Abl-transformed cell lines after imatinib treatment. Interestingly, lncRNA-IUR37 expression levels were significantly lower in leukemic cells derived from Bcr-Abl-positive ALL patients than those in normal control group. Furthermore, altering lncRNA-IUR37 expression remarkably affected survival of Abl-transformed leukemic cells, and tumorigenesis induced by these leukemic cells in xenograft mouse model. Knockdown of lncRNA-IUR37 in transgenic mice significantly promoted Bcr-Abl-mediated primary bone marrow transformation, and leukemia development in leukemia mouse model. These results indicate that lncRNA-IUR37 functions as a suppressor gene in Bcr-Abl-induced tumorigenesis. In addition, we demonstrated that lncRNA-IUR37 directly bound and affected the phosphorylation of STAT5, thereby impacting expression of transferrin receptor protein (TfR or CD71) to regulate leukemic cell survival. Together, our observations suggest that lncRNA-IUR37 is critically involved in Bcr-Abl-mediated leukemogenesis, and provide novel insights into complicated mechanisms underlying cellular transformation by Bcr-Abl oncogene.

Citation Format: Jilong Chen, Xuefei Wang. Identification of a novel imatinib upregulated lncRNA family that is required for efficient cellular transformation by Abl oncogene [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3571.
Abstract 3595: DSP-0692, a selective SCD inhibitor, enhances the anti-tumor activity of anti-PD1 antibody
Authors: Sugaru Eiji , Furuta Yudai , Nagagaki Yoshikazu , Ikeda Satoshi , Fukunaga Yuichi , Umehara Hiroki , Otsubo Tsuguteru , Watanabe Manabu , Tojo Shingo , Hashizume Miki , Matsuki Yasushi , Ban Hitoshi
Published: August 2019

SCD (Stearoyl-CoA Desaturase), a key enzyme for lipid metabolism, is overexpressed in various types of cancer and plays an important role in cancer cell proliferation. We have previously shown that the identification and the functional characterization of DSP-0692, a novel and selective SCD inhibitor. SCD expression was induced in tumor cells cultured in sphere conditions, which were resistant to conventional agents within therapeutic concentration. DSP-0692 showed strong growth inhibition when tumor cells were cultured in sphere conditions, but had little impact on cells cultured under adherent conditions. In addition, DSP-0692 decreased the expression of stemness-related genes in tumor cells as well as in tumor tissues. Treatment with DSP-0692 suppressed tumor growth in multiple models both in single agent or in combination with conventional chemotherapies. DSP-0692 also inhibited WNT/beta-catenin signaling pathway through two different mechanisms (inhibition of Wnt3A secretion and nuclear translocation of beta-catenin). DSP-0692 exhibited lower IC50 value to sphere cells carrying mutations related to WNT/beta-catenin signaling pathway than those without these mutations. Blockade of the coinhibitory checkpoint molecule PD-1 has emerged as an effective treatment for many cancers. However, despite successes in the clinical setting, only a limited subpopulation respond to PD-1 blockade. We hypothesized that the deregulated lipid metabolism of tumor cells and microenvironment function as a barrier to antitumor immunity, and therefore that normalization of lipid metabolism with DSP-0692 might restore response to immunotherapy. Combination of DSP-0692 with anti-PD-1 antibody in the syngeneic CT-26 colon model, a resistant model to anti-PD-1 antibody, augmented tumor regressions relative to each single agent alone. DSP-0692 induced PD-L1 and PD-L2 expression in CT-26 cells, indicating that it is one of a mechanism of restoration of the effect of anti-PD-1 antibody. Our data suggest that remodeling the lipogenic tumor microenvironment has potential to convert patients resistant to immunotherapy into those who may receive clinical benefit of immunotherapy.

Citation Format: Eiji Sugaru, Yudai Furuta, Yoshikazu Nagagaki, Satoshi Ikeda, Yuichi Fukunaga, Hiroki Umehara, Tsuguteru Otsubo, Manabu Watanabe, Shingo Tojo, Miki Hashizume, Yasushi Matsuki, Hitoshi Ban. DSP-0692, a selective SCD inhibitor, enhances the anti-tumor activity of anti-PD1 antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3595.
Abstract 3673: The BMI1/Sp1/IGF1R pathway mediates pemetrexed resistance in non-small cell lung cancer cells
Authors: Wang Wen-Ling , Chien Peng-Ju , Chang Wen-Wei , Wang Bing-Yen
Published: August 2019

Background: Lung cancer is the leading cause of cancer death in Taiwan and worldwide and non-small cell lung cancers (NSCLCs) account for more than 85% of lung cancers. Pemetrexed is approved for several steps of nonsquamous NSCLC therapy but drug resistance often occurs in long-term treatment. Cancer stem cells (CSCs) are considered as the rare subpopulation of cancer cells with the features of tumor initiation, drug resistance, and metastatic capability. The signaling pathway and potential targets contribute to the maintenance of pemetrexed-resistant cancer stem cell remain unknown.

Methods: To investigate the mechanism of pemetrexed resistance in lung cancers, the pemetrexed-resistant A549 cells were established (A400). The sphere-formation assay, western blot analysis and real-time qPCR were employed to identify cancer stem cells and study their properties.

Result: We first discovered that the pemetrexed-resistant A549 cells (called A400) contained more CSC activity than the parental A549 cells including the increased number of tumorspheres and the upregulation of BMI1, c-Myc, Sox2 and p-IGF1Rtyr1165/1166 expression. The treatment of PTC-209, a BMI1 inhibitor, displayed a greater inhibitory effect in cell proliferation in A400 than A549 cells and it suppressed tumorsphere formation capability of A400 cells. In addition, PTC-209 treatment downregulated the expression of IGF1R, p-IGF1Rtyr1165/1166, and Sp1, a positive regulatory transcriptional factor in IGF1R expression, in A400 cells. We also found that Sp1 was increased in A400 when compared to parental A549 cells. With the treatment of Sp1 inhibitor in A400 cells, the expression of IGF1R was suppressed without changing BMI1 level. Finally, we examined the therapeutic effect of BMI1 inhibition in vivo and resulted found that intraperitoneal administration of PTC-209 enhanced the pemetrexed efficacy in NOD/SCID mice harboring A400 xenograft tumors.

Conclusion: Our data reveal that BMI1/Sp1/IGF1R pathway is upregulated in pemetrexed resistant NSCLCs and targeting BMI1 could be a therapeutic strategy in NSCLCs when pemetrexed resistance occurs.

Citation Format: Wen-Ling Wang, Peng-Ju Chien, Wen-Wei Chang, Bing-Yen Wang. The BMI1/Sp1/IGF1R pathway mediates pemetrexed resistance in non-small cell lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3673.
Abstract 3701: Fn14 overexpression in RCAS/tv-a rat gliomas promotes tumor progression, increases invasion and decreases survival
Authors: Connolly Nina , Ames Heather , Tran Nhan L. , Kim Anthony , Winkles Jeff , Woodworth Graeme
Published: August 2019

Fibroblast growth factor-inducible 14 (Fn14) is the cell surface receptor for the tumor necrosis factor (TNF) family member TNF-like weak inducer of apoptosis (TWEAK). The Fn14 gene is not normally expressed in healthy tissues, but expression is significantly increased in many primary solid tumor types, including glioblastoma (GBM). High Fn14 expression in tumors is often associated with the stimulation of cancer cell invasion leading to diffuse, aggressive tumors and metastasis. To investigate the effects of increased Fn14 expression in brain tumors, two different tumor types were developed using the RCAS/tv-a transgenic rat model: a low-Fn14, “proneural-like” (PDGFA/shP53 derived) tumor and a high-Fn14 (PDGFA/shP53/Fn14-derived) tumor. Interestingly, rats with high-Fn14 brain tumors had a significantly shorter median survival compared to those with low-Fn14 with 42 days and 70 days median survival, respectively. Using MR proton spectroscopy, both tumor types exhibited the markers of a malignant glioma such as increases in choline to creatinine ratio (Cho/Cr) and decreases in neuronal activity (NAA); however, high-Fn14 tumors also displayed an increase in lactate during tumor progression which is often a sign of high grade, necrotic tumors and poor prognosis. Morphologically, the two tumor subtypes appear quite different. H&E staining of the high-Fn14 tumors showed a highly malignant tumor with several areas of pseudopalisading necrosis within the tumor core. This is different than the somewhat more homogeneous morphology of the low-Fn14 proneural-like tumor. The pattern of tumor cell invasion also differs between the two brain cancer subtypes. High-Fn14 tumors show a more human GBM-like pattern by invading along the white matter tracts whereas low-Fn14 tumors appear to invade more locally with minimal white matter invasion. High-Fn14 tumors were positive for Fn14 throughout the tumor including the invasive rim of the tumor, which is also seen in human GBM, whereas the low-Fn14 tumor revealed very little staining even at the invasive rim. These findings indicate that increased Fn14 expression creates a more malignant brain tumors that develops and behaves more aggressively then low-Fn14 tumors.

Citation Format: Nina Connolly, Heather Ames, Nhan L. Tran, Anthony Kim, Jeff Winkles, Graeme Woodworth. Fn14 overexpression in RCAS/tv-a rat gliomas promotes tumor progression, increases invasion and decreases survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3701.
Abstract 3724: Molecular mechanisms of TTField action determined by measurements and modelling of electro-conductive properties of microtubules
Authors: Kalra Aarat P. , Patel Sahil , Bhuiyan Asadullah , Preto Jordane , Rezania Vahid , Lewis John D. , Shankar Karthik , Tuszynski Jack
Published: August 2019

Biological effects of AC electric fields at frequencies between 100-300 kHz discovered a decade ago are being applied to cancer cells as a therapeutic modality in the treatment of glioblastoma multiforme (GBM). They are called Tumor Treating Fields (TTFields) as they disrupt cell division. Based on our electro-conductive measurements and modeling, we provide an assessment of possible molecular-level mechanisms. Computer simulations and experimental measurements carried out for microtubules and actin filaments are presented. Charge and dipole values for monomers and dimers as well as polymerized forms of these proteins are summarized. Continuum approximations for cable equations describing actin filaments and microtubules compare favorably to measurements in buffer solutions showing soliton waves and transistor-like amplification of ionic signals, respectively. AC Conductivity and capacitance of tubulin and microtubules have been measured and modeled in the range of frequencies between 1 Hz and 1 MHz. A dramatic change in conductivity occurs when tubulin forms microtubules. In living cells, this signals a conductive phase transition coinciding with mitosis in dividing cells. This process is allowed by TTField penetration into the cleavage furrow in dividing cells and provides the most significant mechanistic explanation of the observed effects. We provide estimates of the forces, energies and power involved in the action of TTFields on microtubules and kinesin motors. These calculations are compared and contrasted with typical values experienced at a cell level and provide strong arguments for real physical effects of TTFields in dividing cells. We also show results of DLS and TEM measurements on microtubules and tubulin oligomers in solution, which allow us to quantify these processes under controlled conditions. In conclusion, the most likely candidates to provide a quantitative explanation of these effects are ionic condensation waves around microtubules as well as dielectrophoretic effects on the dipole moments of microtubules.

Citation Format: Aarat P. Kalra, Sahil Patel, Asadullah Bhuiyan, Jordane Preto, Vahid Rezania, John D. Lewis, Karthik Shankar, Jack Tuszynski. Molecular mechanisms of TTField action determined by measurements and modelling of electro-conductive properties of microtubules [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3724.
Abstract 3739: Characterization of the effects of DIM (3,3’-Diindolylmethane) on irradiated tumors and anti-tumor immunity
Authors: Chen Renxiang , Li Lijun , Lin Lorreta Yun-Tien , Fornace Albert J. , Li Heng-Hong
Published: August 2019

The overall goal of this project is to determine the efficacy of DIM (3,3’-Diindolylmethane) to protect normal tissues during radiotherapy but not enhance the survival of irradiated tumors. We tested expression change of p53-downstream genes in the absence and presence of DIM after radiation exposure using hTERT-immortalized human mammary epithelial cells. Radiation-induced gene inductions for both p21 and Wip1 were found attenuated in cells pretreated with various concentrations of DIM compared to the vehicle control. To reveal DIM’s effects on the global transcriptome of irradiated cells, we performed whole genome gene expression microarray analysis. Pathway analysis results showed that the differentially expressed genes are involved in cell cycle, p53 network, DDR, and related pathways. Gene regulation pattern at the later post-radiation time point in the presence of DIM shows similarity with that of early time point with no DIM, which suggests that DIM treatment delays responses of cell-cycle-related genes. We monitored tumor growth after localized radiation in tumor xenograft models of MDA-MB-231 and HCC1937 human breast carcinoma cell lines using immunocompromised NSG mice. The fractionated regimen consists of a total dose of 24 Gy in four fractions (6 Gy per fraction given every other day) with administration of DIM or vehicle at one hour prior to each fraction. DIM showed no significant effect on the growth of irradiated tumors, i.e. DIM did not affect the treatment efficacy of radiation on tumors. To investigate effects of DIM on tumor microenvironment, we treated tumors with fractioned radiation in an E0771 syngeneic tumor model. DIM treatment enhanced tumor infiltration of lymphocytes population. These studies support the goal of developing DIM as a clinical radioprotector in order to improve the therapeutic index by allowing higher doses of radiation to improve local tumor control by reducing late dose-limiting normal tissue toxicity by radiation.

Citation Format: Renxiang Chen, Lijun Li, Lorreta Yun-Tien Lin, Albert J. Fornace, Heng-Hong Li. Characterization of the effects of DIM (3,3’-Diindolylmethane) on irradiated tumors and anti-tumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3739.
Abstract 3747: Radium 223 inhibits prostate cancer in bone via zonal cytotoxicity
Authors: Dondossola Eleonora , Casarin Stefano , Paindelli Claudia , De-Juan-Pardo Elena , Hutmacher Dietmar , Logothetis Christopher , Friedl Peter
Published: August 2019

Bone metastases are the initial site of progression and account for many complications experienced by men with metastatic prostate cancer (PCa), with limited therapeutic options. Targeting the bone environment has recently resulted in the approval of Radium-223 (Rad-223), a new life-prolonging therapy for patients with metastatic castrate-resistant prostate cancer. Rad-223 is a rare earth metal radioisotope that displays chemical properties similar to calcium, becomes enriched in bone after in vivo administration and emits alpha particles with locally high energy but limited penetrance in tissues (<100 µm). Confoundingly, the clinical response to Radium-223 is often followed by detrimental relapse and progression, and whether Radium-223 causes tumor-cell directed cytotoxicity in vivo remains unclear. We hypothesized that limited radiation penetrance in situ defines outcome and addressed the principles discriminating Radium-223 efficacy from failure by combining 3D intravital microscopy, in silico modeling and end-point analysis in preclinical PCa models in bone. Radium-223 induced profound but zonally confined cancer cell lethality along the bone interface (200-300 µm), while the more distant tumor core remained unperturbed. As consequence, macro-lesions persisted and grew, whereas micro-tumors in the bone niche showed severe growth delay or eradication. The relative inefficacy in controlling large tumors points to application of Radium-223 in secondary prevention of early bone-metastatic disease and regimens co-targeting the tumor core or broadening the zonal toxicity.

Citation Format: Eleonora Dondossola, Stefano Casarin, Claudia Paindelli, Elena De-Juan-Pardo, Dietmar Hutmacher, Christopher Logothetis, Peter Friedl. Radium 223 inhibits prostate cancer in bone via zonal cytotoxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3747.
Abstract 3749: Metabolic reprogramming by GCN1 mediates metastatic reactivation and outgrowth at liver metastatic site in response to glutamine deprivation in pancreatic cancer
Authors: Sinha Surajit , Hernandez Jonathan , Ayabe Reed , Wach Michael , Ruff Samantha , Ranjan Alok , Remmert Kirsten , Alexander Imani
Published: August 2019

Introduction: Disseminated tumor cells in the circulation upon extravasation into a secondary organ like the liver encounter hostile conditions like nutrient deprivation and oxidative stress and may undergo dormancy or growth arrest. The molecular drivers and mechanisms that enable disseminated tumor cells to overcome such adverse growth conditions and revert to proliferative stage are unknown.

Method: To identify these molecular drivers, a retroviral cDNA library was generated from a highly metastatic pancreatic cell line (M-4964Liv) derived from a KPC mouse which forms macroscopic liver lesions upon splenic injection in mice. The cDNA library was then transduced into a dormant pancreatic KPC cells (D-4964Liv) cells which does not give liver lesions upon splenic injection in mice. This methodology will allow all the cDNA’s from the metastatic cells to express in the dormant cells but only those cDNA’s which can trigger the dormant cells to outgrow will give rise to a metastatic liver lesion.

Results: The screening strategy led to the identification of general control of amino-acid synthesis 1-like 1 (GCN1L1). The human homologue GCN1 has been shown to regulate the activation of mammalian amino acid sensor general control non-derepressible 2 (GCN2) under amino acid starvation in budding yeast but how GCN1 regulates metastatic reactivation is not known. We show that GCN1 is activated under physiologic glutamine levels in the liver which is around 0.5 mM compared to standard tissue culture levels of 2-4 mM. Mechanistic interrogation revealed that GCN1 activates both the mammalian amino acid sensors: the general control nonderepressible 2 (GCN2) and the mechanistic target of rapamycin complex 1 (mTORC1) leading to metastatic outgrowth in vivo. Contrary, knockdown of GCN1 dramatically impairs the activation of GCN2 and mTORC1 and abrogates liver metastatic outgrowth upon splenic injection in immunocompetent mice.

Conclusions: These results suggest that under physiologic glutamine levels, induction of GCN1 activates two different pathways: One pathway impinges on ATF4 and the other on mTORC1. While ATF4 activation promotes metabolic homeostasis by inducing de novo amino acid synthesis, the activation of mTOR pathway ensures re-entry in to the cell cycle leading to metastatic reactivation and outgrowth.

Citation Format: Surajit Sinha, Jonathan Hernandez, Reed Ayabe, Michael Wach, Samantha Ruff, Alok Ranjan, Kirsten Remmert, Imani Alexander. Metabolic reprogramming by GCN1 mediates metastatic reactivation and outgrowth at liver metastatic site in response to glutamine deprivation in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3749.
Abstract 3752: Fabrication and validation of an in vitro bone marrow microenvironment for the study of prostate cancer progression
Authors: Kozminsky Molly , Sohn Lydia
Published: August 2019

Metastasis is responsible for the vast majority of cancer deaths, motivating the investigation of how the disease progresses in the face of each obstacle put forth by the body. While disseminated tumor cells (DTCs) are detected in the bone marrow of many prostate cancer patients, only 1% of DTCs yield macrometastases. There is pressing need for an in vitro system to study the characteristics of the interactions with the microenvironment that influence prostate cancer progression. High-throughput DNA-directed single-cell patterning was used to create an in vitro bone-marrow microenvironment that provides replicates of these miniature systems within an easy-to-images conventional chamber slide. This system enables the study of the contributions of several cell types present in the bone marrow microenvironment. Cell types in the in vitro system to be represented by cell lines include bone cells (osteoblasts and osteoclasts), cells of hematopoietic lineage (macrophages, osteoclasts), and endothelial cells. Optimization strategies for cell culture conditions, pattern design, and fabrication parameters will be described as well the incorporation of prostate cancer cells to study cell-cell interactions. Applying high-throughput DNA-directed cell-patterning system yielded a highly complex cellular system that can be used to answer open questions about prostate cancer metastasis.

Citation Format: Molly Kozminsky, Lydia Sohn. Fabrication and validation of an in vitro bone marrow microenvironment for the study of prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3752.
Abstract 3761: Regulation of metastasis by CD8 T lymphocytes
Authors: Joseph Robiya , Soundararajan Rama , Vasaikar Suhas , Yang Fei , Isgandarova Sevinj , Tian Lin , Haemmerle Monika , Mino Barbara , Zhou Tieling , Raja Geraldine Vidhya , Pena Esmeralda Ramirez , Hollander Petra Den , Bhangre Neeraja , Shin Crystal , Martinez Melisa , Canales Jaime Rodriguez , Chang Jeffrey , Sood Anil , Wistuba Ignacio Ivan , Gibbons Don L. , Rosen Jeffrey M. , Acharya Ghanashyam , Varadarajan Navin , Zhang Xiang H. , Mani Sendurai A.
Published: August 2019

Metastatic breast cancer is the most dreadful malignant disease that accounts for the majority of cancer-related deaths worldwide among women. A number of studies have shown that the tumor microenvironment (TME) plays a crucial role in regulating metastasis. It is therefore imperative to understand the dynamic interactions between cancer cells and their microenvironment to examine the molecular interaction and to effectively target cancer cells. TME comprises a variety of cells including immune cells which can influence tumor survival, growth and metastasis. Tumor-infiltrating lymphocytes (TILs), in particular, the CD8 T lymphocytes, has emerged as a promising prognostic marker for immunotherapy in a variety of cancers. However, the key molecular factors that regulate the cross-talk between tumor cells and CD8 T lymphocytes and its impact on metastatic traits in breast cancer is still inconclusive. Platelets are crucial components of the tumor microenvironment that are known to modulate tumor promotion and metastasis. The contribution of platelets and platelet secreted molecules are also carefully examined in metastasis of various cancers. The primary objective of this study is to investigate the role of CD8 T lymphocytes and platelets in breast tumor progression using isogenic tumor lines that form identical primary tumors but differ in their ability to develop metastasis.

Citation Format: Robiya Joseph, Rama Soundararajan, Suhas Vasaikar, Fei Yang, Sevinj Isgandarova, Lin Tian, Monika Haemmerle, Barbara Mino, Tieling Zhou, Geraldine Vidhya Raja, Esmeralda Ramirez Pena, Petra Den Hollander, Neeraja Bhangre, Crystal Shin, Melisa Martinez, Jaime Rodriguez Canales, Jeffrey Chang, Anil Sood, Ignacio Ivan Wistuba, Don L. Gibbons, Jeffrey M. Rosen, Ghanashyam Acharya, Navin Varadarajan, Xiang H. Zhang, Sendurai A. Mani. Regulation of metastasis by CD8 T lymphocytes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3761.
Abstract 3771: Oncogenes and tumour-suppressors drive differential retinoblastoma evolution
Authors: Salcedo Adriana , Watson John D. , Racher Hilary , Rushlow Diane , Espiritu Shadrielle Melijah G. , Sendorek Doroto H. , Prokopec Stephenie D. , Matveski Donco , Yousif Fouad , Livingstone Julie , Gallie Brenda L. , Boutros Paul C.
Published: August 2019

Unlike any other tumour type, retinoblastomas can be driven by only two tumour-initiating events: bi-allelic loss of the tumour suppressor RB1 or amplification of the MYCN oncogene. These mutations drive morphologically indistinguishable tumours that arise at different ages, providing a unique model system to evaluate the influence of initiating mutation on tumour evolution. We performed high-resolution copy number analysis of 101 retinoblastoma and whole genome sequencing of 23. These data reveal that different initiating mutations cause probabilistic changes in somatic point and copy number mutations, but large changes in genomic rearrangements and mitochondrial number. Independent of the initiating mutation, retinoblastomas harbour multiple subclonal populations that preferentially accrue point mutations after subclonal diversification. These subclonal structures suggest caution when choosing chemotherapeutic strategies for primary treatment. Overall, initiating mutations influence evolutionary trajectory more than specific driver mutations: RB1- and MYCN-driven tumours harbour distinct mutational processes, sequences of mutation acquisition and patterns of subclonal diversification. These data show how tumour-initiating mutations drive clinical behaviour by subtly biasing multiple evolutionary processes. Validation in other tumour types is underway.

Citation Format: Adriana Salcedo, John D. Watson, Hilary Racher, Diane Rushlow, Shadrielle Melijah G. Espiritu, Doroto H. Sendorek, Stephenie D. Prokopec, Donco Matveski, Fouad Yousif, Julie Livingstone, Brenda L. Gallie, Paul C. Boutros. Oncogenes and tumour-suppressors drive differential retinoblastoma evolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3771.
Abstract 3787: Reduced expression of INPP4B by promoter hypermethylation in Epstein-Barr virus-associated gastric carcinoma
Authors: Ma Yiwen , Tan Jichao , Dai Weihong , Zhang Yu , Zhang Yu , Lin Rongjin , Xu Yan
Published: August 2019

Background: Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is attracting increasing attention due to distinct molecular and clinical characteristics. However, its carcinogenesis still remains unclear. Previous studies demonstrated that aberrant DNA methylation is one of the pathogenic mechanisms of EBVaGC. Inositol polyphosphate 4-phosphatase type II (INPP4B), as a component of PI3K/AKT pathway, is implicated in the regulation of crucial cellular processes and tumorigenesis. This study aims to reveal the correlation between INPP4B expression and EBV infection, as well as investigate the inactivation mechanism of INPP4B in EBVaGC.

Methods: EBV status and INPP4B expression were examined in gastric carcinoma (GC) tissue microarray (301 cases) using EBV RNA probe and immunohistochemistry, respectively. The correlation of EBV status and INPP4B expression was analyzed in GC by Chi-Squared Test. The INPP4B promoter methylation was investigated in GC cell lines: SNU-719 (EBV positive), AGS (EBV negative) and SGC-7901 (EBV negative) with methylation-specific polymerase chain reaction (MSPCR). After treatment with 5-Aza-2′-deoxycytidine, the INPP4B promoter methylation and expression were detected using MSPCR, western blot, and qPCR.

Results: INPP4B expression is decreased in 146 of 301 GC cases (48.5%). In 272 evaluable GC cases, EBV was present in 40 cases (14.71%). In addition, Lower expression of INPP4B is significantly correlated with EBV infection (p<0.05). There was a significantly decreased expression of INPP4B in EBV positive cell line (SNU-719) compared to EBV negative cell line (AGS and SGC-7901). Moreover, aberrant CpG island hypermethylation of INPP4B was found in SNU-719 rather than AGS and SGC-7901. After treatment with 5-Aza-2′-deoxycytidine, INPP4B protein and mRNA are dramatically up-regulated, while unmethylated DNA became detectable in SNU-719.

Conclusions: Our results suggest that the reduction of INPP4B expression is commonly found in GC, particularly in EBVaGC. Promoter hypermethylation may be one of the mechanisms of INPP4B inactivation.

Citation Format: Yiwen Ma, Jichao Tan, Weihong Dai, Yu Zhang, Yu Zhang, Rongjin Lin, Yan Xu. Reduced expression of INPP4B by promoter hypermethylation in Epstein-Barr virus-associated gastric carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3787.
Abstract 3799: Large-scale pharmacogenomics based drug discovery for ITGB3 dependent chemoresistance in mesenchymal lung cancer
Authors: Lee Haeseung , Kwon Ok-Seon , Kim Wankyu , Cha Hyuk-Jin
Published: August 2019

Even when targets responsible for chemoresistance are identified, drug development is often hampered due to the poor druggability of these proteins. We systematically analyzed therapy-resistance with a large-scale cancer cell transcriptome and drug-response datasets and predicted the candidate drugs based on the gene expression profile. Our results implicated the epithelial-mesenchymal transition as a common mechanism underlying resistance to chemotherapeutic drugs. Notably, we identified ITGB3, whose expression was abundant in both drug resistance and mesenchymal status, as a promising target to overcome chemoresistance. We also confirmed that depletion of ITGB3 sensitized cancer cells to conventional chemotherapeutic drugs by modulating the NF-κB signaling pathway. Considering the poor druggability of ITGB3 and the lack of feasible drugs to directly inhibit this protein, we took an in silico screening for drugs mimicking the transcriptome-level changes caused by knockdown of ITGB3. This approach successfully identified atorvastatin as a novel candidate for drug repurposing, paving an alternative path to drug screening that is applicable to undruggable targets.

Citation Format: Haeseung Lee, Ok-Seon Kwon, Wankyu Kim, Hyuk-Jin Cha. Large-scale pharmacogenomics based drug discovery for ITGB3 dependent chemoresistance in mesenchymal lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3799.
Abstract 3812: Overcoming de novo and acquired modes of cetuximab resistance by broad-spectrum receptor tyrosine kinase inhibitors
Authors: Singh Bhuminder , Graves-Deal Ramona , Bogatcheva Galina , Coffey Robert J.
Published: August 2019

MEK inhibition has been shown to delay emergence of cetuximab resistance in colorectal cancer (CRC) (Nat Commun 22;6:8305, 2015). By exploiting a novel 3D culture system, we herein show that three broad-spectrum tyrosine kinase inhibitors overcome de novo and acquired resistance to cetuximab. By culturing a CRC cell line, HCA-7 in 3D in type I collagen, we previously identified two novel modes of cetuximab resistance. In 3D culture, HCA-7-derived CC are sensitive to cetuximab, while SC exhibit de novo cetuximab resistance (PNAS 114:E2852-E2861, 2017). Continuous exposure of CC to cetuximab resulted in colonies that acquired resistance to cetuximab, designated CC-CR, which was dependent in part on increased levels of lncRNA MIR100HG that leads to increased WNT signaling (Nat Med 23:1331-1341, 2017). We previously showed increased MET and RON tyrosine phosphorylation in SC cells and that MET/RON inhibitor, crizotinib overcomes SC cetuximab resistance. We now show that crizotinib also overcomes acquired cetuximab resistance in CC-CR. A phospho-RTK array showed increased phosphorylation of several RTKs, including MET and RON, in SC and CC-CR cells compared to cetuximab-sensitive CC counterparts. Furthermore, other multi-RTK inhibitors cabozantinib and BMS-777607 helped overcome cetuximab resistance, as measured by 3D colony growth and activation state of key signaling molecules. Conversely, addition of RTK ligands HGF and NRG1 induced cetuximab resistance in CC cells, which could be blocked by addition of crizotinib and this was associated with disorganized spindle positioning during cell division, leading to multi-layering of CC cultures. By FACS analysis, we observed increased cell cycle arrest in G1 phase in SC and CC-CR cultures treated with cetuximab and crizotinib. Furthermore, we show that crizotinib overcomes cetuximab resistance in vivo in SC nude mice xenografts. Finally, in a direct comparison between vertical suppression (EGFR/MEK inhibition) and parallel inhibition (EGFR/multi-RTK inhibition), we observed a higher degree of synergy with the latter strategy. The non-overlapping toxicities of cetuximab and crizotinib warrants consideration for its clinical deployment.

Note: This abstract was not presented at the meeting.

Citation Format: Bhuminder Singh, Ramona Graves-Deal, Galina Bogatcheva, Robert J. Coffey. Overcoming de novo and acquired modes of cetuximab resistance by broad-spectrum receptor tyrosine kinase inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3812.
Abstract 3819: Amphiregulin in damaged tumor microenvironment potentiates therapeutic resistance and enables PD-L1-mediated immunosuppression
Authors: Xu Qixia , Coppé Jean-Philippe , Campisi Judith , Lam Eric , Sun Yu
Published: August 2019

Therapeutic resistance is the major barrier to conquer human cancer, the most lethal pathology that claims numerous lives per year. Although identification of resistance mechanisms is the key to develop optimal strategies, progress has been limited due to long term failure to reveal the most critical targets. Cancer cells exhibit high plasticity even in clinical settings, a phenomenon that contributes to disease refraction by developing intrinsic or acquired resistance. Here we highlight the multifaceted and genetically conserved senescence-associated secretory phenotype (SASP), which encodes a large array of soluble factors including amphiregulin (AREG). Expression of AREG is markedly inducible by DNA damage to stromal cells in the tumor microenvironment (TME), a process mediated predominantly by the NF-κB complex and C/EBP family. Stromal AREG remarkably enhances the malignancy of cancer cells including acquired resistance, mainly by activating the EGFR pathway and causing a distinct epithelial to endothelial transition (EET). Paracrine AREG induces PD-L1 expression in recipient cancer cells, thereby creating an immunosuppressive TME via immune checkpoint activation. Therapeutic targeting AREG by a monoclonal antibody not only remarkably deprived cancer cells of chemoresistance, but achieved prominent efficiency when combined with classical chemotherapy in humanized animals with restored immunocompetency. Stromal AREG enters circulation and is readily detectable in the peripheral blood of post-treatment patients, representing a novel liquid biopsy biomarker for therapeutic evaluation and disease prognosis. Our study substantiates the potential of in vivo SASP in driving the TME-mediated drug resistance and shaping an immunosuppressive niche, and provides the proof-of-principle of targeting major SASP factors to effectively improve therapeutic index with reduced mortality.

Citation Format: Qixia Xu, Jean-Philippe Coppé, Judith Campisi, Eric Lam, Yu Sun. Amphiregulin in damaged tumor microenvironment potentiates therapeutic resistance and enables PD-L1-mediated immunosuppression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3819.
Abstract 3843: LSD1 modulation by allosteric ligands
Authors: Emond Wei B. , Geitmann Matthis , Jarvius Malin , Koehler Konrad , Källblad Per , Niklasson Mia , Parrow Vendela , Sawant Rajiv , Sjöberg Maria , Winquist Johan , Segerman Anna , Bremberg Ulf
Published: August 2019

LSD1 has emerged as a potential therapeutic target for a number of cancer types (e.g. AML, SCLC, colorectal, breast, liver, prostate, glioblastoma, Ewing sarcoma), as well as sickle cell anaemia and Alzheimer’s disease. Irreversible LSD1 catalytic inhibitors have shown limited clinical efficacy in AML and SCLC, while solid tumours are largely unaddressed. This is in contrast to LSD1 knockdown with impact on a wide range of cancers, indicating that LSD1 functions other than enzymatic should be targeted.

We have developed novel small molecules that modulate LSD1 via an allosteric site - without inhibiting its enzymatic function - inducing a 60% reduction of nuclear LSD1 levels. The sensitivity profile in a cancer cell line panel is unique and dissimilar to >300 diverse reference compounds. In vitro efficacy is observed in glioma-initiating clones that are highly resistant to standard-of-care temozolimide as well as catalytic LSD1 inhibitors. Efficacy in the sub-µM range is observed with other solid tumour models, e.g. prostate cancer. The compounds exhibit synergy (Bliss independence >40%) with HDAC inhibitors as evaluated by viability in cellular cancer models, including lung, liver and glioblastoma.

Pharmacokinetic studies show good blood-brain-barrier penetration and oral availability of the allosteric LSD1 modulator BEA-17. A repeat dose of 25 mg/kg was well tolerated by NOD SCID mice, leading to µM level accumulation in the brain. Results from orthotopic glioblastoma PDX models, and in vivo hollow-fiber models of other solid tumours will be presented, as well as mechanistic insights from biophysical assays and gene expression analysis.

Citation Format: Wei B. Emond, Matthis Geitmann, Malin Jarvius, Konrad Koehler, Per Källblad, Mia Niklasson, Vendela Parrow, Rajiv Sawant, Maria Sjöberg, Johan Winquist, Anna Segerman, Ulf Bremberg. LSD1 modulation by allosteric ligands [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3843.