bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the relative copy numbers of TP63, YAP1 and KMT2D genetic loci and EGFR expression in orthotopic patient-derived xenografts of cardioesophageal cancer in immunodeficient mice.
Authors: Goncharova Anna S. , Kolesnikov Evgeniy N. , Zaikina Ekaterina V. , Volkova A. V. , Mindar M. V. , Khodakova D. V. , Lukbanova Ekaterina A. , Kurbanova L. Z. , Kozhushko Mikhail A. , Anisimov Aleksandr E. , Myagkov Roman E. , Sanamyants Sergey V. , Katsieva Tanzila B. 
Published: June 2021

e15033 Background: Cardioesophageal cancer is a common tumor affecting the cardiac stomach and lower esophagus. Tumor heterogeneity is important, since it can cause the ineffectiveness of chemotherapy and radiotherapy due to individual characteristics of the neoplasm in different patients, as well as the intensification of invasion and metastasis. Our purpose was to analyze the relative copy numbers of TP63, YAP1 and KMT2D genetic loci and EGFR expression in orthotopic patient-derived xenografts of cardioesophageal cancer. Methods: The model of cardioesophageal cancer was created in Balb/c Nude mice with surgical bioptates of adenocarcinoma obtained from donors. The relative copy numbers of TP63, YAP1 and KMT2D genetic loci and EGFR expression were determined by Real-Time qPCR. Results: A PDX model of cardioesophageal cancer was successfully created by transplanting a moderately differentiated adenocarcinoma from a patient diagnosed with infiltrative ulcerative cancer of the lower third of the esophagus with a transition to the cardiac stomach into the distal esophagus of Balb/c Nude mice. The EGFR expression was elevated in patient tumor samples, compared to healthy tissues (p = 0.021) and gastric cancer xenografts (p = 0.07). Molecular genetic analysis demonstrated an association between an increased EGFR expression and changes in the relative copy numbers of TP63, YAP1, and KMT2D in donor samples compared to gastric cancer xenografts (p = 0.02, p = 0.026 and p = 0.042). Conclusions: The relative copy numbers of TP63, YAP1, and KMT2D were associated with intensified EGFR expression and changed with each new generation of orthotopic xenografts.
Development of a DNA damage response (DDR) therapeutics platform for oncology.
Authors: Das Debanu , Duncton Matthew , Pellicena Patricia , Deacon Ashley , Wilson David , Georgiadis Millie 
Published: June 2021

e15036 Background: Cancer cells respond to increases in DNA damage by deploying their DNA damage response (DDR) pathways. We are building a platform for the discovery and development of target-specific DDR therapeutics, including small molecule inhibitors and targeted protein degradation warheads, founded on fragment- and structure-based drug discovery. Methods: Our DDR platform, which includes hit-to-lead, lead optimization and candidate selection, starts with hit generation from a new technology that uses high-throughput protein X-ray crystallography to directly screen compound libraries. Our hit generation process produces empirical evidence of direct target engagement. The elucidation of high-quality ligand-bound 3D structures reveals the location and pose of the ligand and details of the protein-ligand interactions. Thus we can predict the structure-function consequences of the hit molecule engagement, which sets the stage for rapid assessment of synthetic tractability and intellectual property. After hit identification, we apply a multi-pronged approach in hit-to-lead conversion and lead optimization using iterative biophysical and biochemical assays, coupled with crystallography. We are applying our approach to several new targets in DDR and will present some early progress in this space. Results: Apurinic/apyrimidinic endonuclease 1 (APE1) is the major repair enzyme for abasic sites in DNA and contributes to DNA strand break processing. Many studies have associated increased APE1 levels with enhanced growth, migration, and drug resistance in human tumor cells, and with decreased patient survival. APE1 has been implicated in over 20 human cancers, including glioblastoma, making the protein an attractive target for the development of anticancer therapeutics. Despite intensive effort, there are no clinical endonuclease inhibitors of APE1. We have identified 25 diverse small molecule fragments that bind to APE1 at two distinct sites, including the endonuclease site. Pol eta (or PolH) is a DNA polymerase implicated, among other things, in the development of cisplatin resistance in a subset of ovarian cancers. In our quest to develop PolH inhibitors, we have identified 5 diverse fragments that bind to two distinct sites in the polymerase including a new potential allosteric site. Our results on APE1 and PolH represent the first known cases of crystal structures of small molecules bound to these proteins. Flap endonuclease (FEN1) is implicated in several cancers including for example ER/tamoxifen-resistant breast cancer. We are developing a targeted protein degradation approach using PROTACs (Proteolysis-Targeting Chimeras) toward the development of novel therapeutics against FEN1. Conclusions: Our results will help us develop small molecule inhibitors and targeted protein degradation against DDR targets that may be effective as single therapies or be used to make existing therapies more effective.
Towards the clinical validity of tumor organoid drug screens: Establishing a framework for organoid disease models.
Authors: Slostad Jessica , Masood Ashiq , Swoboda April T. , Levy Mia Alyce 
Published: June 2021

e15037 Background: Despite advances in biomarker-directed cancer therapies to predict tumor response to treatment, precision oncology remains an imprecise science. Tumor organoid drug screens present an opportunity to test multiple potentially effective therapies simultaneously before exposing a patient to treatment toxicities. Preliminary studies have established the analytic validity; however, the clinical validity of the tumor organoid response to a drug to predict the tumor response in patients is unclear. Methods: In order to establish the clinical validity of an organoid drug screen, a clinical disease model should have the following features to enable comparison of the tumor’s clinical response to treatment and the organoid’s response to the same treatment. First, a fresh tissue biopsy (non-bone) needs to be obtained for organoid development prior to the start of systemic treatment. Priority should be given to tumors known to successfully grow organoids. Disease models where the standard of care systemic treatment is a single cytotoxic or targeted agent would best assess correlation between the drug screen and patient response, such as metastatic breast, cervical, or prostate cancer. This would often lead to enrolling patients on later line systemic therapies. Studies should avoid drugs whose mechanism of action leverages the patient metabolism or tumor microenvironment (e.g. immunotherapy, aromatase inhibitors, VEGF inhibitors). Patient should have measurable disease that can be measured clinically, radiographically, or pathologically and using standardized response evaluation criteria (e.g. RECIST). Next generation sequencing would assess genomic concordance between the tumor in the patient and organoid. These studies would determine the feasibility and timeliness of prospectively developing tumor organoids that is sufficient to perform a drug screen. Results: We propose two research models to evaluate the clinical validity of tumor organoid drug screens: a metastatic solid tumor and neoadjuvant solid tumor disease model. Metastatic disease models provide an opportunity to assess response across multiple cancer types at the time of progression and initiation of next line of therapy. The efficacy of chemotherapy can be determined using objective data from radiologic response (RECIST). In neoadjuvant models, pathologic (pCR) and radiologic response can provide objective data for organoid response. These study design features will lay the framework for determining the clinical utility of organoid drug screens. Conclusions: We call for clinical studies assessing the clinical validity of tumor organoid drug screens and determining their concordance with patient response to systemic therapy. Advancements in clinically validated tumor organoids have the potential to fundamentally shift clinical paradigms and improve patient outcomes in cancer treatment.
Cytoprotective effects of spirulina extract against doxorubicin‐induced cardiotoxicity: Biochemical evidences and translational perspectives in cardio-oncology.
Authors: Maurea Nicola , Quagliariello Vincenzo , Paccone Andrea , De Laurentiis Michelino , Buccolo Simona , Iovine Martina , Botti Gerardo 
Published: June 2021

e15042 Background: Spirulina, a blue-green algae used in the daily diet of natives of Africa and America, has antioxidant, anticancer, antiviral, hepatoprotective, immune enhancing and lipid-lowering effects. Considering that doxorubicin-induced cardiotoxicity involves myocardial inflammation, ferroptosis and overexpression of several cytokines involved in cell dead and apoptosis, the use of spirulina during exposure to doxorubicin could be an intriguing method to reduces myocardial injuries in cancer patients undergoing treatment with anthracyclines. Methods: Human fetal cardiomyocytes (HFC cell line) were exposed to doxorubicin (from 10 to 500 nM), alone or in combination with spirulina extract (from 10 to 100 µg/ml) for 24 and 48h. After the incubation period, we performed the following tests: determination of cell viability, through analysis of mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of TLR4/MyD88; mTORC1 Fox01/3a; transcriptional activation of p65/NF-κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6). Results: Spirulina extract, co-incubated with doxorubicin exerts cardioprotective effects, enhancing cell viability of 20-36.7 % compared to untreated cells (p<0,01 for all); spirulina extract reduced significantly the cardiotoxicity through MyD88/NF-KB/cytokines axis and mTORC1 Fox01/3α mediated mechanisms and reduces oxidative damages of doxorubicin resulting in lower intracellular calcium content. Conclusions: For the first time, it was demonstrated that spirulina extract exert anti-inflammatory and cytoprotective properties in myocardial cells exposed to growing concentration of doxorubicin leading to preclinical studies in mice analyzing any effects on cardiac strain and left ventricular ejection function.
New tropolone derivative to inhibit cell motility in colorectal cancer cells.
Authors: Mezhevova Irina V. , Filippova Svetlana Yu. , Timofeeva Sofia V. , Sitkovskaya Anastasia O. , Shamova Tatiana V. , Lukbanova Ekaterina A. , Goncharova Anna S. , Gusakov Evgeniy A. , Sayapin Yuriy A. , Kolesnikov Vladimir E. , Kolesnikov Valeriy V. , Sidorenko Maria , Panchenko Pavel , Kit Oleg I. 
Published: June 2021

e15043 Background: Tropolones are small, naturally occurring organic compounds that have anti-cancer effects in a variety of cancer cell lines. Among proposed mechanisms of tropolone derivatives anti-cancer activity are caspase activation, matrix metalloproteinases and histone deacetylases inhibition and other actions. Since matrix metalloproteinases are the major proteins that contribute to tumor cell tissue invasion and migration their blockers are extensively studied as prospective anti metastatic agents. We assumed that tropolones may also have potential as metastases prevention drugs. The aim of the study was to investigate the influence of new tropolone derivative 2-(6,8-dimethyl-5-nitro-4-chloroquinolin-2-yl)-5,6,7-trichloro-1,3-tropolone on the cell migration capacity in colorectal cancer cells. Methods: Cell migration in permanent colorectal cancer cell lines HT29, Caco2 and HCT116 was studied using the standard wound healing assay with automated image acquisition and analysis on Lionheart FX (BioTek) cell imager. Cell cultures were maintained in DMEM medium with L-glutamine (1 μM) (Gibco) and 10% FBS (Gibco) at 37C0 and 5.0% CO2. The day before assay establishment cells were seeded at 250 000 cells per well on 24-well plates. After attachment of cells, a vertical wound in cell layer was made manually in each well, and then medium with studied tropolone derivative (5 μM) was added. Plates with cells were continuously incubated and photographed in cell imager at 37C0 and 5.0% CO2. The extent of cells migration was measured as the percent of wound area decrease after 48 hours of incubation in relation to starting time point. Data are given as: Mean ± 95% confidence interval. Results: The new tropolone derivative under study exhibited pronounced anti migratory activity in all studied colorectal cancer cell cultures. The most prominent effect was observed in HCT116 cell line: after 48 hours of incubation relative wound area decrease was 48.2%±5.7% in control and 7.2%±3.15% in experimental groups. In Caco2 cell line cell migration inhibition was the least with 65%± 6.9% relative wound area decrease in control and 51.5%± 7.7% in experimental groups. The moderate effect was observed in HT29 cell line (measured parameter was 63.6%±7.6% and 36.9%±11.6% in control and experimental groups accordingly). The obtained difference between control and experimental groups was significant in all tested cell cultures at 0.05 level (df = 30). Conclusions: Results of the present study prove tropolone derivative to be prospective candidates for anti-metastatic drug development. Further investigations are needed to reveal the exact mechanisms of tropolones anti-migratory activity.
Antimigratory effect of berberine in T98G, U87MG and primary glioma cell culture.
Authors: Mezhevova Irina V. , Filippova Svetlana Yu. , Timofeeva Sofia V. , Sitkovskaya Anastasia O. , Shamova Tatiana V. , Enin Yaroslav S. , Burov Oleg N. , Pozdnyakova Viktoria V. , Khokhlova Olga , Pushkareva Tatiana F. , Mezentsev Stanislav S. , Novikova Inna A. , Kit Oleg I. 
Published: June 2021

e15045 Background: Berberine is an alkaloid compound with a structure that is highly similar to that of intercalating agents. It affects numerous cell signaling pathways and is widely studied as potential anticancer drug. It is known that berberine affects cancer cells migration through metalloproteinase-2 inhibition, but this effect was never studied on glioma cells. Anti-migratory drugs are of special interest in brain cancer therapy since glioma's highly invasive nature makes total surgical removal of tumor practically impossible. The aim of the study was to evaluate berberine anti-migratory activity on glioma cells. Methods: Cell migration capacity of T98G and U87MG cell lines, as well as primary glioma cell culture established in our laboratory, was assessed via standard wound healing assay with automated image acquisition and analysis on Lionheart FX (BioTek) cell imager. Prior to assay setting up cell cultures were maintained in DMEM medium with L-glutamine (1 μM) (Gibco) and 10% FBS (Gibco) at 37C0 and 5.0% CO2. Cells were seeded at 250 000 cells per well on 24-well plates and incubated overnight in order to attach to plate bottom. After that a vertical wound was made manually in each well, and berberine was added to experimental wells to final concentration 50 mg/L. Plates with cells were continuously incubated and photographed in cell imager at 37C0 and 5.0% CO2. The extent of cells migration was measured as the percent of wound area decrease after 24 hours of incubation in relation to starting time point. Data are given as: Mean ± 95% confidence interval. Results: In our study we berberine exhibited anti-migratory activity in all cell cultures under study. In rather fast growing primary cell culture wound area decrease was 99.23%±0.62% in control sample and 91.75%±0.28% in experimental sample. The difference was small but significant at p < 0.001 level (df = 30). Popular permanent glioma cell lines T98G and U87MG showed more prominent decrease in studied parameter with higher degree of variance at the same time. In T98G wound area decrease was 71.6%±12.3% in control and 48.8%± 7.6% in experimental samples after 24 hours of cultivation in presence of 50 mg/L berberine. While U87MG demonstrated 60.28%±5.13% and 37.5%± 8.34% wound area decrease accordingly. The obtained difference between control and experimental groups in permanent cell cultures was statistically significant at the 0.05 level (df = 30). Conclusions: Our preliminary research proved berberine to be potent anti-migratory agent in glioma treatment. Further investigations are needed to evaluate its ability to inhibit glioma cell expansion in vivo.
The functional significance of ATM phosphorylation of Bub3 on Serine 135 in sensitivity to DNA damaging agents.
Authors: Zhang Siyue , Xiao Mingming , Liu Zhuang , Mo Yaqi , Liu Hong , Xu Bo 
Published: June 2021

e15048 Background: Identification of biomarkers to assess and modify the sensitivity of cancer cells to radiotherapy and chemotherapy is critical to improve cancer treatment outcome. Budding uninhibited by benzimidazoles 3 (Bub3) is a mitotic checkpoint protein, and it is frequently overexpressed in many cancers and associated with low survival rates. Bub3 is involved in the repair of DNA damage induced by radiotherapy and chemotherapy. We recently identified that the ATM kinase phosphorylated Bub3 on Serine 135 (S135) via the stable isotope labeled amino acid in cell culture -mass spectrometry analysis. This study aims to explore the mechanism of ATM-phosphorylated Bub3 in the DNA damage response (DDR) and its effect on tumor sensitivity to DNA damaging agents. Methods: The radiosensitivity of the cells was detected by clonal formation assay, the proliferation ability of the cells was detected by the MTS assay. The expression of DDR protein γ-H2AX in the nucleus was detected by immunofluorescence assay. Genomic instability was observed by multinuclear formation. Co-immunoprecipitation and Western Blot were used to explore the internal mechanism of ATM phosphorylation of Bub3 in DDR. Results: We showed that ionizing radiation (IR) could induce Bub3 S/TQ (the specific ATM consensus motif) phosphorylation in an ATM dependent manner. Mutation of Bub3 Serine 135 to alanine (S135A) led to a phosphorylation defect. Phenotypic experiments showed hypersensitivity to IR in cells expressing Bub3 S135A. Bub3 S135A prolonged existence of γ-H2AX foci and increased the proportion of cells containing micronuclei. Further, we found that Ku70 and Ku80 showed a significant increase after IR in their interactions with Bub3, while Bub3 S135A mutation significantly reduced the interaction, leading to impaired DNA repair. Conclusions: We demonstrate that Bub3 S135 phosphorylation mediated by ATM is essential for an optimal DDR and disruption of this pathway increases tumor sensitivity to DNA damaging agents.
Bispecific anti-PD-1/PD-L1 antibody CTX-8371 to promote cellular clustering and PD-1 shedding, antitumor activity and tolerability.
Authors: Albu Diana I. , Qin Yan , Wang Xianzhe , Li Vivian , Kim Taeg , Gong Bing , Schuetz Thomas , Kuklin Nelly 
Published: June 2021

e15056 Background: Checkpoint blockade therapies targeting PD-1 and PD-L1 have shown great success for the treatment of various malignancies. However, a substantial fraction of patients with PD-L1-positive tumors remain unresponsive to these therapies. Novel therapy with significantly greater activity than the leading PD-1/PD-L1 inhibitors is expected to bring additional clinical benefit to patients. Here we describe the preclinical evaluation of CTX-8371, which combines anti-PD-1 and anti-PD-L1 monoclonal antibodies in one bispecific tetravalent molecule. Methods: The immune-enhancing activity of CTX-8371 was tested in vitro in T cell activation assays and tumor cell killing assay. CTX-8371 anti-tumor efficacy in vivo was assessed using mouse tumor cells expressing human PD-L1 implanted in transgenic mice humanized at the PD-1 and PD-L1 loci. CTX-8371 anti-tumor activity was also tested in xenograft tumor models. The mechanism of action of CTX-8371 was investigated in vitro using Jurkat cells expressing PD-1 or PD-L1, human PBMCs, and in vivo in tumor-bearing, chimeric PD-1/PD-L1 transgenic mice. CTX-8371 PK was determined in mice using an MSD ELISA-based assay and in cynomolgus monkeys using a qualified ELISA method. Dose range finding and toxicokinetic studies were performed in cynomolgus monkeys. Results: CTX-8371 potently enhanced T cell activation and function in vitro and showed curative efficacy as monotherapy in multiple solid tumor models, isografts or xenografts. Furthermore, CTX-8371 demonstrated superior anti-tumor efficacy compared to Keytruda or atezolizumab in checkpoint inhibitors-sensitive and resistant syngeneic mouse tumor models. Mechanistically, in addition to blocking PD-1 interaction with PD-L1, CTX-8371 bispecific antibody facilitated cell to cell bridging between cells expressing PD-1 and cells expressing PD-L1. Furthermore, we show that simultaneous binding of CTX-8371 to both PD-1 and PD-L1 resulted in long term PD-1 shedding. This suggests that CTX-8371 may prevent or overcome T cell exhaustion within the tumor microenvironment, thus providing additional advantage over existing therapies. Lastly, excellent tolerability was observed in non-human primates given 2 weekly drug infusions at up to 50 mg/kg dose. Conclusions: CTX-8371 displays multiple mechanisms of action over monoclonal PD1/PD-L1 blockade. These unique pharmacological properties of CTX-8371 could explain the enhanced T cell responses to tumor antigens and superior efficacy over current monoclonal antibody therapies. With favorable PK/PD and toxicology profiles in mice and cynomolgus monkeys, CTX-8371 warrants further advancement to clinical testing.