bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 355: Histone acetyltransferase KAT6A upregulates PI3K/AKT signaling through TRIM24 binding
Authors: Lv Deguan , Jia Feng , Hou Yanli , Sang Youzhou , Alvarez Angel A. , Zhang Weiwei , Hu Bo , Cheng Shi-Yuan , Ge Jianwei , Li Yanxin , Feng Haizhong
Published: August 2018

Lysine acetyltransferase KAT6A is a chromatin regulator that contributes to histone modification and cancer, but the basis of its actions are not well understood. Here we identify a KAT6A signaling pathway that facilitates glioblastoma (GBM) where it is upregulated. KAT6A expression was associated with GBM patient survival. KAT6A silencing suppressed cell proliferation, cell migration, colony formation and tumor development in an orthotopic mouse xenograft model system. Mechanistic investigations demonstrated that KAT6A acetylates lysine 23 of histone H3 (H3K23), which recruits the nuclear receptor binding protein TRIM24 to activate PIK3CA transcription, thereby enhancing PI3K/AKT signaling and tumorigenesis. Overexpressing activated AKT or PIK3CA rescued the growth inhibition due to KAT6A silencing. Conversely, the pan-PI3K inhibitor LY294002 abrogated the growth-promoting effect of KAT6A. Overexpression of KAT6A or TRIM24, but not KAT6A acetyltransferase activity- deficient mutants or TRIM24 mutants lacking H3K23ac binding sites promoted PIK3CA expression, AKT phosphorylation and cell proliferation. Taken together, our results define an essential role of KAT6A in glioma formation, rationalizing its candidacy as a therapeutic target for GBM treatment.

Citation Format: Deguan Lv, Feng Jia, Yanli Hou, Youzhou Sang, Angel A. Alvarez, Weiwei Zhang, Bo Hu, Shi-Yuan Cheng, Jianwei Ge, Yanxin Li, Haizhong Feng. Histone acetyltransferase KAT6A upregulates PI3K/AKT signaling through TRIM24 binding [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 355.
Abstract 3554: The role of P2RY14 in acute leukemia
Authors: Shah Kinjal , Kazi Julhash
Published: August 2018

Leukemia is a group of blood cancers that originate in the bone marrow and involves uncontrolled proliferation of different types of blood cells. The PI3K/mTOR pathway is the second most frequently deregulated pathway in a majority of cancers such as breast cancer, lung cancer and melanomas as well as leukemia. There are several promising drugs targeting this pathway for use in the clinic. However, acquired resistance to the drugs remains a major challenge to overcome. Mutations in the genes coding for receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs) are quite common in all forms of acute leukemia. This can be a major cause of deregulation of the PI3K-mTOR pathway. To understand how cells display resistance to the dual PI3K/mTOR inhibitor, we used a panel of acute leukemic cell lines. We observed that while a number of cell lines displayed sensitivity to the dual PI3K/mTOR pathway inhibitor PKI-587, many cells displayed substantial resistance. Cells sensitive to PKI-587 also showed aberrant activation of the PI3K/mTOR pathway and also displayed sensitivity to a panel of various other PI3K/mTOR inhibitors. Using RNA sequencing data from the COSMIC database, we compared gene expression between the cell lines that are either resistant or sensitive to PKI-587. We found that the expression of P2RY14 was around 9-fold upregulated in cells showing resistance to PKI-587. Thus, we identified Purinergic receptor 14, P2RY14, as the target gene. P2RY14 is a G protein-coupled receptor that has not been much studied in hematologic malignancies. However, this receptor seems to have a role in the localization of Hematopoietic Stem Cells (HSCs) and in promoting regenerative capabilities following injury. Acute lymphoblastic leukemia patients with higher expression of P2RY14 mRNA displayed relatively poor survival compared to patients carrying the lower expression of P2RY14. To understand the role of this receptor in leukemia, we stably transfected the murine pro B cell line Ba/F3 with P2RY14. Activation of P2RY14 by its ligand, UDP glucose, resulted in selective induction of ERK1/2 phosphorylation. Taken together, our data suggest that the GPCR P2RY14 couples to ERK signaling which probably has a significant role in acute leukemia. Nevertheless, further in vitro testing of the receptor functionality with various biochemical and molecular biology techniques is required before this receptor, P2RY14, can be utilized as a therapeutic target in the future treatment of acute leukemia.

Citation Format: Kinjal Shah, Julhash Kazi. The role of P2RY14 in acute leukemia [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 3554.
Abstract 3555: TREM2 is upregulated and plays oncogenic role in gastric cancer
Authors: Zheng Yulong , Jiang Lihua , Xiao Cheng , Xu Nong , Gao Qiqi , Yao Yinan , Hu Yongxian , Sun Yun , Xu Xin
Published: August 2018

Background

Triggering receptor expressed on myeloid cells-2 (TREM2) is thought to be invovled in innate immunity and inflammation regulation. More recently, the importance of TREM2 has been highlighted by identification in several kinds of solid tumors. Nonetheless, the oncogenic roles and potential molecular mechanisms of TREM2 in gastric cancer (GC) remain unknown.

Methods

The expression levels of TREM2 were determined by quantitative PCR (qPCR) and immunohistochemistry (IHC). MTT, colony formation, 5-Ethynyl-2′-deoxyuridine (EdU) incorporation, and in vivo tumorigenicity assays were performed to determine the pro-proliferative role of TREM2 in GC cells. mRNA sequencing, qPCR, and Western blotting were used to explore the underlying molecular mechanism of pro-proliferative role of TREM2 in GC cells.

Results

The mRNA expression of TREM2 was markedly up-regulated in tumor tissues (n=16) in comparison with that in corresponding non-tumorous tissues. Immunohistochemical study were performed to determine the protein expression in 108 patients with surgically resected GC. Its expression was positively associated with TNM stage (P=0.023) and T classification (P=0.021), and was inversly correlated with the poor clinical outcome of the patients.

The human GC cell lines MGC-803 and BGC-823 were used for proliferation analysis. The transfected GC cell lines with stable overexpression of TREM2 were established. Ectopic overexpression of TREM2 in GC cells promoted cell proliferation,

whereas loss of TREM2 function inhibited proliferation. In vivo animal experiments further validated the pro-proliferative role of TREM2. Deep sequencing to profile global gene expression of MGC-803 cells with TREM2 overexpression. In the biological process analysis, these differentially expressed genes were mainly involved in the MAPK signaling. Molecular mechanistic investigations explored that TREM2 upregulated GREM1 expression, thereby activating ERK1/2 signaling via VEGFR2-PLC-γ-PKC axis and promoting GC cell proliferation.

Conclusion

High TREM2 expression predicts poor prognosis in GC and TREM2 promotes GC cells proliferation. Our findings suggest that GREM1-VEGFR2-PLC-γ-PKC-ERK1/2 signaling axis contributes to the oncogenic roles of TREM2 on GC cells. TREM2 could be an effective prognostic biomarker and a potential therapeutic target.

Citation Format: Yulong Zheng, Lihua Jiang, Cheng Xiao, Nong Xu, Qiqi Gao, Yinan Yao, Yongxian Hu, Yun Sun, Xin Xu. TREM2 is upregulated and plays oncogenic role in gastric 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 3555.
Abstract 356: Polyadenyaltion of canonical histone mRNA: A potential mechanism of arsenic-induced carcinogenesis
Authors: Chen Qiao Yi , Chen Danqi , Kluz Thomas , Wu Feng , Zhu Yusha , Marais Thomas Des , Li Jinquan , Zhang Xiaoru , Jordan Ashley , Sun Hong , Jin Chunyuan , Costa Max
Published: August 2018

Naturally occurring inorganic arsenic has been identified as a prominent causal agent in lung, bladder, liver, and prostate cancers. Although arsenic (As) has long been known to induce carcinogenicity via epigenetic mechanisms, alteration in histone gene expression has not been explored. The replication-dependent histone genes (also known as canonical histone genes) are the only genes found in multicellular organisms whose messenger RNA (mRNA) does not terminate with a poly(A) tail at the 3' end. Instead, they contain a conserved 26-nucleotide sequence that forms a stem-loop structure, and serves as the binding site for the Stem-loop binding protein (SLBP). SLBP is critical for canonical histone pre-mRNA processing and histone mRNA translation. Our previous studies demonstrated that arsenic exposure increases polyadenylation of histone H3.1 mRNA (a canonical histone H3) and its presence outside of S phase of the cell cycle due to the loss of SLBP protein and mRNA. Here we report that ectopic expression of polyadenylated H3.1 mRNA induces cell transformation and that the transformed cells are able to form tumors in athymic nude mice. These carcinogenic effects are dependent on the level of polyadenylation of canonical H3.1 mRNA. Notably, transfection of H3.1 cDNA with a stem-loop sequence in the front of the poly(A) signal generates less polyadenylated H3.1 mRNA and thereby attenuates cell transformation. Furthermore, the increase in polyadenylated H3.1 mRNA is able to antagonize histone H3.3 (a non-canonical variant of H3) in the promoter of active genes and perturb expression of cancer-related genes. In addition transfection of H3.1 with a poly(A) tail causes mitotic block in the cell cycle as well as chromosome instability. Furthermore, acute arsenic exposure by inhalation in mice results in the loss of SLBP and gain of polyadenylated H3.1 mRNA in lung tissues. These results suggest that the polyadenylation of canonical histone mRNAs induce by Arsenic is very disruptive to cellular genomic integrity and contributes to development of human cancers.

Citation Format: Qiao Yi Chen, Danqi Chen, Thomas Kluz, Feng Wu, Yusha Zhu, Thomas Des Marais, Jinquan Li, Xiaoru Zhang, Ashley Jordan, Hong Sun, Chunyuan Jin, Max Costa. Polyadenyaltion of canonical histone mRNA: A potential mechanism of arsenic-induced carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 356.
Abstract 3562: Merkel cell polyomavirus t-antigen regulates aggresome formation and autophagy in merkel cell carcinoma
Authors: Shi Hao
Published: August 2018

Merkel cell carcinoma (MCC) is an aggressive and deadly skin cancer. About 80% of MCCs harbor integrated Merkel cell polyomavirus (MCV) genome with a mutation in the large T (LT) gene, leading to expression of truncated LT and intact small T (sT). The molecular mechanism how the virus contributes to MCC development is still not fully understood. Paranuclear dot-like staining of cytokeratin 20 is a typical characteristic of MCC. However, it is unexplored whether these dot-like structures are functionally important in MCC. In this study, we aimed to characterize the identity of these dot-like structures and to determine whether MCV T-antigens play a role in the formation of these structures. Using immunostaining, we showed that these structures were co-localized with aggresome markers (including intermediate filaments, BAG3 and HSP70) and were localized at the microtubule organization center, as demonstrated by the presence of γ-tubulin. These structures became dispersed to the periphery upon microtubule depolymerization using colcemid. Similarly, silencing of BAG3 in MCV-positive MCC cells resulted in aggresome clearance. Interestingly, we observed that these structures were associated with MCV-positive MCCs and silencing of MCV T-antigens led to dispersion of the aggresome. Additionally, ectopically expressed truncated, but not wild-type, LT could facilitate aggresome formation in MCV-negative cells. We also showed that silencing of MCV T-antigens induced autophagy in MCV-positive MCC cells, while ectopically expressed MCV T-antigens suppressed autophagy in MCV-negative MCC cells. In conclusion, we uncover a novel role of MCV T-antigen in hijacking cellular degradation pathways, suggesting that the autophagy-aggresome pathway plays important roles in MCV infection and MCC tumorigenesis.

Citation Format: Hao Shi. Merkel cell polyomavirus t-antigen regulates aggresome formation and autophagy in merkel cell carcinoma [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 3562.
Abstract 3585: T cell receptor-stabilized regenerated CD8ab cytotoxic T lymphocytes for cancer immunotherapy
Authors: Minagawa Atsutaka , Hotta Akitsu , Kawai Yohei , Yasui Yutaka , Uemura Yasushi , Yasukawa Masaki , Nakatsura Tetsuya , Kaneko Shin
Published: August 2018

The use of antigen-specific T cell derived induced iPSCs as a cell source for regeneration of cytotoxic T lymphocytes (CTLs) have advantages in rejuvenation profile, and reproducible number of CTLs. However for the safe and efficient regenerated T cell immunotherapy, strict antigen specificity is essential. Here we report CD8αβ T cells differentiated from T cell-derived iPSCs underwent additional rearrangement of the T cell receptor (TCR) α-chain gene at the CD4/CD8 double positive stage during in vitro differentiation and lost antigen specificity. CRISPR knockout of a recombinase gene in the T-iPSCs successfully prevented this additional TCR rearrangement. Moreover, when CD8αβ T cells were differentiated from non-T cell-derived but antigen-specific TCR-transduced iPSCs, they showed monoclonal expression of the transduced TCR. TCR stabilized regenerated CD8αβ T cells effectively inhibit tumor growth in xenograft cancer models. These approaches could contribute to safe and effective regenerative T cell immunotherapies.

Citation Format: Atsutaka Minagawa, Akitsu Hotta, Yohei Kawai, Yutaka Yasui, Yasushi Uemura, Masaki Yasukawa, Tetsuya Nakatsura, Shin Kaneko. T cell receptor-stabilized regenerated CD8ab cytotoxic T lymphocytes for cancer immunotherapy [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 3585.
Abstract 3586: A universal killer T-cell for adoptive cell therapy of cancer
Authors: Dillard Pierre , Mensali Nadia , Myklebust June Helen , Hebeisen Mickael , Skorstad Gjertrud , Myrhe Marit Renee , Fåne Anne , Gaudernack Gustav , Kvalheim Gunnar , Inderberg Else Marit , Wälchli Sebastien
Published: August 2018

T cell-mediated immunotherapy of cancer has achieved remarkable results in hard-to-beat cancers. The main challenge of adoptive T-cell transfer (ACT) is its labor intensive and costly production and logistics as well as its dependency on the quality of the patient's T cells. To overcome these hurdles we have designed a universal cell line for TCR expression by modifying the FDA-approved NK cell line, NK-92. Advantages of using this cell line is that it is easy to expand and can readily be genetically engineered. However, tumor cell recognition and killing by NK-92 is not antigen specific. This can be controlled by introducing an antigen receptor, such as a chimeric antigen receptor (CAR) or, as in the current work, a TCR. We herein present evidence that NK-92 can be modified to become a T cell-like lymphocyte which we named UK-92 cell (Universal Killer). UK-92 expressing a therapeutic TCR showed conserved binding capacity to the cognate pMHC. Phosphoflow cytometry results indicated that the introduced TCR was able to mediate intracellular signaling upon either crosslinking or cognate pMHC binding. Our data showed that both early and late TCR signalling players were activated in a TCR-specific manner (anti-CD3/anti-CD28 stimulation) and further in a pMHC specific manner. In vitro functional assays using TCRs isolated from both CD8 and CD4 T cells demonstrated that UK-92-TCR could be stimulated in a pMHC-specific manner and, importantly, could kill tumor cells specifically even in a tumor-like microenvironment such as spheroids. We have now shown in vitro that UK-92 cells are as specific and potent as redirected T cells to kill target cells. Finally, encouraging in vivo data showed that mice receiving UK92 cells expressing a therapeutic TCR experienced reduction in tumor load and enhanced survival compared with control mice. If confirmed, the use of UK92 as a universal cell line might pave the way to truly off-the-shelf therapeutic effector cells for cancer immunotherapy and leading to drastic reduction of cell production time, logistic and cost.

Citation Format: Pierre Dillard, Nadia Mensali, June Helen Myklebust, Mickael Hebeisen, Gjertrud Skorstad, Marit Renee Myrhe, Anne Fåne, Gustav Gaudernack, Gunnar Kvalheim, Else Marit Inderberg, Sebastien Wälchli. A universal killer T-cell for adoptive cell therapy of 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 3586.
Abstract 3588: ACTallo: A novel approach using gamma-delta T cells to allogeneic cellular therapy to treat cancer
Authors: Dao Mo , Mata Melinda , Alten Leonie , Nowicka Aleksandra , Kuttruff Sabrina , Missel Sarah , Mohamed Ali , Weinschenk Toni , Bulliard Yannick , Walter Steffen
Published: August 2018

Adoptive cellular therapy (ACT) has dramatically changed the landscape of cancer immunotherapy; however, the complex manufacture of individualized products from late-stage, heavily pre-treated cancer patients, together with high cost-of-goods, encourages the development of simpler ‘off-the-shelf' alternatives. The unique properties of γδ (gamma-delta) T cells make them a seductive candidate for effective allogeneic ACT. In contrast to αβ T cells, γδ T cells are endowed with intrinsic antitumor activity while unable to induce graft-versus-host disease. γδ T cells have a high proliferative potential before exhibiting exhaustion. Moreover, in the context of αβ TCR-engineered ACT, γδ T cells pose a lesser risk of off-target toxicity, due to the absence of expression of endogenous αβ TCR and hence, risk of mispairing with the engineered αβ TCR.

Here, we will present the ACTallo® platform, which combines the unique properties of γδ T cells with Immatics' XPRESIDENT® target/TCR discovery platform. The ACTallo® process selectively expands Vγ9Vδ2 T cells that are retrovirally-transduced to co-express CD8 together with a tumor-specific αβ TCR. Over a period of 45 days or less, ACTallo® γδ T cells can expand >30,000 fold. γδ T cells obtained this way recognize tumor cells, express cytokines, degranulate and kill tumor cells specifically. In addition, ACTallo® γδ T cells show no signs of exhaustion after expansion, as evidenced by the lack of expression of PD1, TIM3 or LAG3. ACTallo® is intended to overcome the limitation of autologous cellular therapies towards off-the-shelf approach, by combining the large-scale expansion potential of allogeneic γδ T cells with novel TCRs against XPRESIDENT® mass-spectrometry guided tumor-specific targets.

Citation Format: Mo Dao, Melinda Mata, Leonie Alten, Aleksandra Nowicka, Sabrina Kuttruff, Sarah Missel, Ali Mohamed, Toni Weinschenk, Yannick Bulliard, Steffen Walter. ACTallo: A novel approach using gamma-delta T cells to allogeneic cellular therapy to treat 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 3588.
Abstract 3593: Noncoding RNAs in early detection of radiation-induced late pulmonary effects
Authors: Yadav Marshleen , Song Feifei , Qamri Zahida , Chakravarti Arnab , Jacob Naduparambil K.
Published: August 2018

Normal tissue toxicity is an undesired outcome in patients receiving radiation therapy, manifested as acute radiation syndromes (ARS) and as late effects in survivors. The purpose of the study is to develop biomarkers for assessing the extent of lung inflammation and early detection of delayed and late radiation toxicities such as pneumonitis and pulmonary fibrosis. Circulating miRNAs offer great promise as diagnostic predictive biomarkers due to their high abundance, high stability and sensitivity. A longitudinal analysis of evolutionarily conserved noncoding RNAs was done using NanoString platform in serum samples from leukemia patients and pneumonitis-prone BALB/c mice exposed to clinically relevant doses of whole-body, organ-targeted/protected irradiation to compare the treatment-induced alterations. The associated immune response was evaluated by cytokine multiplexing and gene expression analysis and imaging with micro-CT. Bleomycin and targeted miRNA knockout mice models were used to evaluate functional significance of the identified biomarkers. Quantification of time-dependent alterations in serum and plasma miRNAs from rodents samples collected after thoracic, gut versus whole-body exposure have identified a panel of five miRNAs that are capable of providing an early readout of delayed lung toxicities. The specificity of the candidate miRNAs as potential early indicators of lung injury was confirmed in a bleomycin model of acute lung injury where an overlapping miRNA signature was observed in serum. Among these conserved miRNAs, serum miR-21 and miR-29a were found significantly elevated in two weeks in lung irradiated animals with concomitant increase in proinflammatory cytokines. The significance of the markers was further validated in serum miRNA profile of leukemia patients who exhibited pneumonitis symptoms post radiation therapy. The functional role of miR-21 in promoting radiation-induced inflammation was evident from compromised response of genes associated with inflammation in irradiated miR-21-/- mice. Our study has identified a panel of evolutionarily and functionally conserved sensitive miRNA biomarkers that facilitate rapid and early detection of late pulmonary toxicities in leukemia and lung cancer patients who receive therapeutic radiation. Analysis of circulating biomarkers will potentially assist in making therapeutic and follow-up decision based on individual's own physiologic response and developing strategies for timely mitigation and treatment.

Citation Format: Marshleen Yadav, Feifei Song, Zahida Qamri, Arnab Chakravarti, Naduparambil K. Jacob. Noncoding RNAs in early detection of radiation-induced late pulmonary effects [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 3593.
Abstract 36: Novel age-related tumor promoting and inhibiting genes in breast cancer
Authors: Wang Bingzhi , Gu Xiang , Zhu Haiyan , Sun Luzhe
Published: August 2018

During aging, besides genetic alterations, genes with altered expression may promote breast cancer development. Using linear regression modeling, we identified 148 up-regulated and 189 down-regulated genes during aging, by analyzing the whole transcriptome profiling data of matched normal tissues from 82 female patients with age and menopausal status available from The Cancer Genome Atlas data. We also compared matched tumor and normal samples, 3356 up-regulated and 3124 down-regulated genes were identified to be affected by tumorigenesis. Overlapping of tumorigenesis-associated genes with age-dependent genes resulted in 14 up-regulated and 24 down-regulated genes with both age and tumorigenesis. These genes were significantly predictive in relapse free survival, indicative of their potential tumor promoting or suppressive functions respectively. To test this hypothesis, we selected two up-regulated genes-DYNLT3 and P4HA3, and two down-regulated genes-ALX4 and WDR86 to investigate their function in controlling breast cancer malignancy because they are novel genes to breast cancer. We found that knockdown of DYNLT3 or P4HA3, and overexpression of ALX4, significantly reduced breast cancer cell proliferation, migration and colony forming capacity in soft agar, while overexpression of WDR86 did not show any inhibitory activity in breast cancer cells. Consistent with the in vitro data, knockdown of DYNLT3, P4HA3 and overexpression of ALX4 inhibited tumor growth and lung metastasis when breast cancer cells were orthotopically implanted in mice, whereas such inhibition was not observed in mice when WDR86-overexpressing breast cancer cells were implanted. Taken together, our results support that some age-related genes harbor tumor promoting or inhibiting functions. Thus, proper modulation of their expression has potential to prevent or slow down the progression of breast cancer.

Citation Format: Bingzhi Wang, Xiang Gu, Haiyan Zhu, Luzhe Sun. Novel age-related tumor promoting and inhibiting genes in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 36.
Abstract 360: The role of polybromo1 in stress response
Authors: Porter Elizabeth G. , Dykhuizen Emily C.
Published: August 2018

Polybromo1 (PBRM1) is mutated in 3.5% of human cancers with the highest incident in renal clear cell carcinoma (40%). PBRM1 is a member of the PBRM1-Brg-Associating Factors (PBAF) chromatin remodeling complex and is characterized by six tandem bromodomains. PBRM1 acts as a tumor suppressor and when deleted along with VHL, the most frequently mutated gene in RCCC, tumors develop in mice. We have previously shown that PBRM1 regulates the expression of genes involved in cell adhesion, apoptosis, and negative cell proliferation in a RCCC cell line. Additionally, we have demonstrated that four of the six bromodomains work together to regulate binding of the complex to chromatin, gene expression, and tumor suppression in RCCC, which correlates with pattern of PBRM1 missense mutations found in RCCC patient tumors. Through this work we identified histone 3 lysine 14 acetylation (H3K14Ac) as the chromatin mark essential for PBRM1 binding. While H3K14Ac is generally found at active promoters, it is also induced at the promoters of stress genes when cells experience stressors such as metabolic stress, osmotic stress, ER stress, or reactive oxygen species (ROS) stress. Knockdown of PBRM1 in normal epithelial cells leads to an increase in proliferation and a partial epithelial to mesenchymal transition (EMT), consistent with low grade ROS. RNA-seq analysis further confirmed a role for PBRM1 in regulating stress response genes. Although loss of PBRM1 increases proliferation in epithelial cells, it also increases cell vulnerability to high levels of ROS. Together this suggests that PBRM1 can be growth promoting or growth inhibiting to cells depending on the cells environment and stress response needs.

Citation Format: Elizabeth G. Porter, Emily C. Dykhuizen. The role of polybromo1 in stress response [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 360.
Abstract 3600: Early detection of esophageal adenocarcinoma using near-infrared lectin-based imaging
Authors: Neves Andre A. , Pietro Massimiliano Di , O'Donovan Maria , Waterhouse Dale J. , Bohndiek Sarah E. , Brindle Kevin M. , Fitzgerald Rebecca C.
Published: August 2018

Background: Long procedure times and sampling error frequently limit the efficacy of endoscopic surveillance for Barrett's esophagus (BE). Near-infrared (NIR) fluorescence imaging minimizes optical scattering and tissue autofluorescence. We assessed, in an ex vivo setting, the feasibility of using a topically applied NIR dye-labeled lectin for the detection of early neoplasia in BE.

Methods: We recruited consecutive patients undergoing endoscopic mucosal resection (EMR) for BE-related early neoplasia. EMR specimens were freshly collected and sprayed at the bedside with a fluorescent lectin and then imaged ex vivo. A maximum of two punch biopsies were collected from each EMR under NIR light guidance. Fluorescence intensity from dysplastic and nondysplastic areas within EMRs were compared and from punch biopsies with different histological grades.

Results: We analyzed 29 EMR specimens from 17 patients. Dysplastic regions showed significantly lower fluorescence across whole EMR specimens (P < 0.001). A 41% reduction in fluorescence was found for dysplastic compared to nondysplastic punch biopsies (P < 0.001), with a sensitivity and specificity for dysplasia detection of 80% and 82.9%, respectively.

Conclusion: NIR imaging using fluorescently-labeled lectins can distinguish dysplastic from nondysplastic Barrett's mucosa ex vivo. We are currently planning a first-in-human study to validate this imaging platform.

Citation Format: Andre A. Neves, Massimiliano Di Pietro, Maria O'Donovan, Dale J. Waterhouse, Sarah E. Bohndiek, Kevin M. Brindle, Rebecca C. Fitzgerald. Early detection of esophageal adenocarcinoma using near-infrared lectin-based imaging [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 3600.
Abstract 3601: Targeting USP7/PTEN axis regulates the metastatic competency of bone marrow-resident melanoma cells
Authors: Vishnoi Monika , Boral Debasish , Liu Haowen N. , Sprouse Marc L. , Yin Wei , Davies Michael A. , Oliva Isabella C. Glitza , Marchetti Dario
Published: August 2018

Recurrence is the major cause of melanoma death due to cell dissemination from primary/metastatic tumor (CTCs). During asymptomatic periods, these cells reside in bone marrow (bone-marrow resident tumor [BMRT cells]) and remain quiescent. We hypothesized that disseminated tumor cells survive in bone marrow (BM) during these periods and evolve to metastatic potency during disease progression. First, we isolated CTC-enriched, Lin-neg population from clinically advanced melanoma patients and performed biomarker expression and mutational profiling to confirm presence of putative CTCs. Lin-neg CTC population contained unique transcriptomics signature with elevated melanoma markers expression (BAGE, MAGEA1, B4GALNT1, S100A3). Further, downstream IPA analysis demonstrated that an upregulation of transcripts for genes involved in cell survival and pro-development functions with concomitant decrease in cell proliferative and inflammation properties. Second, we implanted Lin-neg population in murine xenograft models and isolated HLA+/ Melan-A+ cells population from blood and BM at endpoint. Expression of human (HLA-ABC) and melanoma markers (Melan-A, S100, NG2, CD146) on BMRTCs and CTCs was confirmed by employing: (a) immunofluorescence staining, (b) single-cell DEPArrayTM and CellSearchTM capture, (c) genomic profiling, and (d) organ-site colonization of CTCs with concomitant to BMRTCs in BM. Third, we discovered distinct transcriptomic signature of BMRTCs vs CTCs by differential gene expression profiling. Subsequent pathway analysis showed top five altered canonical pathways in BMRTCs: protein ubiquitination pathway, EIF2, actin cytoskeleton, systemic lupus erythematosus and hypoxia signaling. Of note, a strikingly elevated expression of PTEN in BMRTCs was detected. Fourth, because PTEN binds to USP7, a key component of protein ubiquitination pathway, we evaluated USP7/PTEN axis in CTC-driven BMRTCs modulated metastatic competency. The use of two clinically approved USP7 inhibitors to study their effects on the proliferative capacity of BMRTCs led to a significant reduction of CTCs at metastatic sites. This study provides critical insights to identify biomarkers of melanoma recurrence during the asymptomatic periods of the disease, fostering application of USP7 inhibitors for innovative melanoma therapies for patients with metastasis undetectable disease and/or yet to develop metastasis.

Citation Format: Monika Vishnoi, Debasish Boral, Haowen N. Liu, Marc L. Sprouse, Wei Yin, Michael A. Davies, Isabella C. Glitza Oliva, Dario Marchetti. Targeting USP7/PTEN axis regulates the metastatic competency of bone marrow-resident 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 3601.
Abstract 3604: Centrosome amplification in epcam-captured circulating tumor cells from metastatic cancer patients
Authors: Singh Ashok , Denu Ryan A. , Sperger Jamie M. , Weaver Beth A. , Burkard Mark E. , Lang Joshua M.
Published: August 2018

Background: Genomic instability and evolution of cancers is linked to chemotherapy sensitivity and resistance in patients with metastatic cancer. Taxane-based chemotherapies operate by promoting chromosomal instability (CIN) by increasing multipolar mitoses. Breast tumors with CIN are more sensitive to paclitaxel compared to tumors without CIN. There is a critical need for new biomarkers based on biological evaluation of mechanisms of response and resistance in metastatic cancer. Although CIN is difficult to detect directly, centrosome amplification (CA) is a common mechanism of CIN. In this study, we develop an assay to detect CA in circulating tumor cells (CTCs) as a minimally invasive assay to evaluate sensitivity to taxane-based chemotherapies.

Methods: Blood samples from patients with metastatic breast and prostate cancer were collected and processed for nucleated cells using a Ficoll gradient and magnetic depletion of CD45-positive cells. EpCAM-positive CTCs were captured using an exclusion-based sample preparation technology known as the VERSA (Versatile Exclusion-based Rare Sample Analysis) platform. CTCs were defined as cells positive for Hoechst, cytokeratin and negative for multiple immune and endothelial cell markers (CD45/CD11b/CD14 and CD34). EpCAM-captured CTCs were also stained with pericentrin and centrin to identify CA and evaluated for pericentrin (whole centrosome marker) and centrin (centriole marker) protein-staining intensity, number and size.

Results: CA was detected in a subset of CTCs from patients with metastatic breast and prostate cancer patients. As a control, centrosomes were also analyzed in matched peripheral blood mononuclear cells from the same patients. CA was heterogeneous with 100% of patients demonstrating some degree of CA (>4 centrioles), ranging from 15-48% of CTCs.

Conclusion: In conclusion, we report the presence of CA in EpCAM-captured CTCs from metastatic cancer patients. Evaluation of CA in CTCs using pericentrin and centrin staining may serve as a predictive biomarker of taxane based chemotherapy response and resistance. We are recruiting taxane-naïve metastatic cancer patients to test the hypothesis that CA and/or CIN predict taxane sensitivity.

Citation Format: Ashok Singh, Ryan A. Denu, Jamie M. Sperger, Beth A. Weaver, Mark E. Burkard, Joshua M. Lang. Centrosome amplification in epcam-captured circulating tumor cells from metastatic cancer patients [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 3604.
Abstract 3619: The role of CXCR4 in progression of malignant glioma
Authors: Liu Mingli
Published: August 2018

High grade malignant gliomas are devastating, uniformly fatal cancers for which no effective therapies exist. Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. Recent studies have shown that cytokines/chemokines can regulate many malignant features of tumor cells. CXCL12/CXCR4 axis activates various signaling pathways that promote chemotaxis, adhesion and migration, cell proliferation and survival. PI3 kinase, Ras, stress-activated protein kinase (SAPK)/c-Jun Nterminal kinase (JNK), phospholipase C (PLC)/mitogen-activated protein kinase (MAPK), p38 MAPK and AKT are all downstream effectors of CXCL12/CXCR4 axis, through which tumor cell growth, dissemination and migration are facilitated. To enhance our understanding of the development and progression of glioma which may lead to novel and useful biomarkers and/or therapeutic targets in the context of GBM, we analyzed the role of CXCR4 in glioma using the published data and literature. (1).To determine the prognostic role of CXCR4 in malignant glioma, we analyzed the microarray data from Rembrandt Databases by Affymetrix HG U133 v2.0 Plus on 523 glioma patients. Kaplan-Meier analysis of overall survival showed that glioma patients with high CXCR4 expression (n=329) have short overall survival compared to those with low CXCR4 expression (n=54), logrank test: P=2.2e-8 9. Among GBM, high CXCR4 expression (n=178) have short overall survival compared to those with low CXCR4 expression (n=9), logrank test: P=0.044. Among Astrocytoma, high CXCR4 expression (n=102) have short overall survival compared to those with low CXCR4 expression (n=33), logrank test: P=0.0247 (http://www.betastasis.com/glioma/rembrandt/kaplan-meier_survival_curve/). (2).To determine the relationship between glioma progression and chemokine receptor CXCR4, we made a meta-analysis based on 14 published articles. All 14 eligible studies having 805 patients from China and USA were included. These studies showed that CXCR4 expression in glioma was correlated to high WHO grade glioma (OR=8.26, 95% CI=3.42-19.93, P<0.00001). Our results indicate that CXCR4 is a predictive marker for malignant glioma progression and survival. Suppression of CXCR4 inhibited proliferation, migration, and invasion of malignant human gliomas indicating that CXCR4 may represent a novel and promising target for therapeutic intervention of malignant glioma.

Citation Format: Mingli Liu. The role of CXCR4 in progression of malignant glioma [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 3619.
Abstract 3622: Identify prognostic biomarkers for colorectal cancer by human villi development model
Authors: Zhang Botao , Feng Lin , Xiao Ting , Cheng Shujun
Published: August 2018

Background Tumorigenesis and embryogenesis have many similar biological characteristics, such as proliferation, invasion, metabolism and immunity. The development of villi is a physiological process, it will stop after the fetus is born. Trophoblast have been defined as "physiological metastasis" or "pseudo-malignant". However, tumorigenesis is a pathological process that will go on indefinitely. We hypothesize that if the interactions between gene and gene in tumors deviate from the interactions in villi, it is more likely to develop into malignant tumors and have worse prognosis.

Methods We collected tissue samples including human chorionic villus samples at 6 to 10 weeks of gestation (n = 15) and leaf chorionic samples from postpartum placental tissue (n = 6), then extracted RNA and carried out RNA sequencing. We processed bioinformatics analysis in combination with multi-stage colorectal cancer (CRC) transcriptome data, including normal (n = 12), low-grade adenoma (n = 21), high-grade adenoma (n = 30), cancer (n = 25).

Results We found that CRC progress and villi development involve many genes with similar biological behaviors, such as proliferation, immunity, metabolism and invasion, but the genes of the relevant biological behavior are different between CRC and villi. Then we filtered those genes, of which the interactions in CRC are far from that in villi. Twenty-four genes, such as CBL, COL1A1, ATP5C1, CDC42 etc were finally selected. Abnormal expression of the 24 genes was significantly associated with poor survival in six independent CRC cohorts (The Cancer Genome Atlas, P<0.001; GSE39084, P= 0.002; GSE14333, P<0.001; GSE17536, P=0.003; GSE39582, P<0.001; GSE29621, P=0.001).

Conclusions Villi development is a reliable and strictly regulated model that can illuminate the trajectory of human cancer development. Our study indicated that the interactions between gene and gene in CRC development deviate from that in villi, the deviation interactions of gene may have some substantial impacts on CRC development and reveal novel prognostic biomarkers.

Citation Format: Botao Zhang, Lin Feng, Ting Xiao, Shujun Cheng. Identify prognostic biomarkers for colorectal cancer by human villi development model [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 3622.
Abstract 3628: PD-1 checkpoint blockade therapy enhances adoptive immunotherapy by human Vγ2Vδ2 T cells against prostate tumors in a preclinical model
Authors: Nada Mohanad H. , Wang Hong , Morita Craig
Published: August 2018

Cancer immunotherapy is an effective treatment against a variety of malignancies. Checkpoint blockade with anti-PD-1 or anti-CTLA-4 antibodies has resulted in durable clinical responses. However, targeting PD-1 or PD-L1 provides clinical benefits for only a minority of patients. Moreover, the effectiveness of checkpoint blockade correlates with the numbers of nonsynonymous mutations present in the tumor explaining the poor responsiveness of certain tumors such as prostate cancers. Therefore, additional therapies are needed for patients not currently responding.

Unlike αβT cells, the anti-tumor activity of Vγ2Vδ2 T cells does not require MHC and is independent of the number of tumor mutations. Instead, Vγ2Vδ2 T cells use their TCRs to surveil tumor cells for alterations in isoprenoids metabolism induced by bisphosphonate treatment in a process requiring butyrophilin 3A1. This allows Vγ2Vδ2 T cells to recognize and kill all types of tumors. In clinical trials involving more than 200 patients, adoptive immunotherapy with Vγ2Vδ2 T cells has been proven to be safe. However, there have been few partial or complete responses with the most common beneficial response being stable disease. To find ways to increase its effectiveness, we have now assessed the benefits of combining PD-1 checkpoint blockade with the adoptive transfer of human Vγ2Vδ2 T cells. Vγ2Vδ2 T cells were found to express the major inhibitory receptors, PD-1, CTLA-4, LAG3, and TIM3 at varying times during the fourteen day ex vivo expansion period. To assess the effect of checkpoint blockade in vivo, immunodeficient NSG mice were inoculated with human PC-3 prostate cancer cells that naturally express the PD-L1 ligand. After 2 weeks, weekly treatments were started with intravenous pamidronate followed a day later by purified Vγ2Vδ2 T cells combined with either anti-PD-1 (clone J116) or control IgG1 mAbs. The addition of anti-PD-1 mAb treatment, markedly enhanced Vγ2Vδ2 T cell immunity to PC-3 tumors. Combination treatment was able to reduce tumor volume almost to zero after 5 weeks. These results demonstrate that PD-1 checkpoint blockade can greatly enhance adoptive immunotherapy with γδ T cells in a preclinical tumor model and suggests that combination therapy with anti-PD1 and Vγ2Vδ2T cells could be an effective strategy to treat patients with a variety of cancers.

Citation Format: Mohanad H. Nada, Hong Wang, Craig Morita. PD-1 checkpoint blockade therapy enhances adoptive immunotherapy by human Vγ2Vδ2 T cells against prostate tumors in a preclinical model [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 3628.
Abstract 3629: Repeated abscopal effect with radiation and anti-PD-1 blockade in MMR deficient endometrial cancer
Authors: Oh Michael S. , Chae Young
Published: August 2018

The combination of radiation therapy and immune checkpoint inhibitors has raised interest as possibly having synergistic antitumor effects. Radiation can induce both a local response as well as a systemic one that stimulates immune cells, which then can be further potentiated by immunotherapy. This abscopal effect has been validated in preclinical studies and is currently being studied in clinical trials, though it has yet to be reported in gynecologic cancers. A 64-year-old woman initially presented with vaginal bleeding and was subsequently diagnosed with stage IIIC endometrial adenocarcinoma with pelvic and para-aortic lymphadenopathy. She underwent surgical resection with adjuvant carboplatin and paclitaxel. Follow-up CT scans showed progression of disease, and over the next 18 months, the patient was sequentially treated with doxorubicin, topotecan, melphalan, docetaxel, and capecitabine. Analysis of a tumor biopsy demonstrated an MMR deficient phenotype with absent MLH1 and PMS2. Based on the recently-published data on the efficacy of PD-1 inhibitors in MMR deficient solid tumors, the patient was started on nivolumab. Meanwhile, she was given palliative radiation therapy to the following areas: painful cutaneous metastases on her left thigh; an L3 spinal metastasis; lymph nodes in the retroperitoneum, external iliacs, and left inguinal chain; and a symptomatic bladder mass. After radiation, the patient exhibited a strong partial response not only in the targeted lesions but also throughout her tumor burden, consistent with an abscopal effect. This response was sustained over many months and repeatable with each radiation session. The synergistic use of radiation therapy and immune checkpoint blockade may thus represent a powerful treatment modality in endometrial cancer and warrants further clinical investigation.

Citation Format: Michael S. Oh, Young Chae. Repeated abscopal effect with radiation and anti-PD-1 blockade in MMR deficient endometrial 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 3629.