tbuckley/cabot-search huggingface dataset:
Abstract LB-038: Development and characterization of cancer cell line exosomes as reference standards in cancer research
Authors: Siddhartha Paul, Nanda Mahashetty, Joy Wells, Dezhong Yin, Fang Tian
Journal: Cancer Research (2019)

Abstract Exosomes are subcellular particles 50-200 nm in size released from cells through a fusion of multicellular bodies with the plasma membrane. Exosomes are currently being evaluated as potential diagnostic tools in a number of diseases, including cancer. Exosomes are stable carriers of cell-free cargo in the form of DNA, RNA, and protein, thereby making them an attractive candidate for early detection of cancer via liquid biopsy. Tumor-derived exosomes have been linked to stimulation of tumor cell growth, angiogenesis, metastasis, and suppression of the immune system. However, isolating a consistent population of exosomes can be challenging and there is an unmet need for highly characterized exosomes for use as reference standards for research and diagnostic applications. We have developed a novel method employing tangential flow filtration for the isolation of large quantities of highly purified, ready to use exosomes from cell culture supernatant. Exosomes from a variety of cancer cell lines representing the most prevalent cancer types, including prostate (LNCaP), colorectal (HCT116), breast (MDA-MB-231, MCF-7), lung (A549), cervical (HeLa), and glioblastoma (U87-MG) were isolated and characterized in this study. We employed a stringent quality control approach in order to define and characterize these exosomes. Our method generated a high yield (&amp;gt;1×1010 exosomes/mL) and average protein equivalent of 2 mg/mL. Our data demonstrated expression of a number of different characteristic exosomal proteins including tetraspanin, which was confirmed through western blot and PCR. Isolated exosomes had a median size of 102 nm through nanoparticle tracking analysis. Western blot data revealed cell line specific protein marker expression of CD63, CD81, flotillin 1, Alix and TSG101 protein. We assessed the functionality of these purified exosomes through cellular uptake, migration assay, and anchorage independent growth assay in this study. We also evaluated exosomal RNA from these purified exosomes for the presence of common mutations associated with cancer through PCR. Here we report that exosomes isolated by our method not only had high exosome yield and quality, but also retained relevant functionality and thereby make ideal reference standards/controls in the field of cancer research and diagnostics development. Citation Format: Siddhartha Paul, Nanda Mahashetty, Joy Wells, Dezhong Yin, Fang Tian. Development and characterization of cancer cell line exosomes as reference standards in cancer research [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 LB-038.
Abstract 3795: Antibiotics induce mitochondrial dysfunction, DNA damage and aerobic glycolysis of human mammary epithelia and fibroblast
Authors: Robert L. Elliott, Xianpeng Jiang
Journal: Cancer Research (2019)

Abstract Mitochondria evolved from free-living bacteria after being endocytosed by eukaryotic host cells millions of year ago. We hypothesized that antibiotics could cause mammalian mitochondrial damage while causing bacterial lethality. Mitochondrial toxicity of three antibiotics, azithromycin, doxycycline and ciprofloxacin, were tested in human mammary epithelia MCF-12A and fibroblast by fluorescent and transmission electron microscopy. Gene expression and DNA damage were tested by real time polymerase chain reaction (qPCR) and ELISA. We found antibiotics suppressed the mitochondrial membrane potential gradient of MCF-12A and fibroblast. Ultrastructural studies showed that antibiotics caused vacuolated swollen mitochondria with disrupted cristae in MCF-12A and fibroblast, compared to the ultrastructure of mitochondria in the cells without antibiotic treatment. Fluorescent microscopy revealed antibiotics induce mitochondrial reactive oxygen species (ROS), superoxide, after 3 hours of culture. The DNA oxidative damage product, 8-OHdG, was significantly increased in the media after MCF-12A and fibroblast were cultured in antibiotic media for 24 hours. Antibiotics upregulated gene expression of hypoxia inducible factor 1 alpha (HIF1a), glycolytic enzymes including hexokinase 2(HK2), phosphofructokinase 1 (PFKM) and pyruvate kinase muscle isozyme M2 (PKM2), lactate dehydrogenase A (LDHA), and glucose transporters 1 (SLC2A1) and 3 (SLC2A3) in MCF-12A and fibroblast. Lactate production was also increased in the culture media of healthy cells MCF-12A and fibroblast cells, confirming aerobic glycolysis, or “the Warburg effect”, the method to generate energy after cells are treated with antibiotics. In summary, antibiotics caused mitochondrial toxicity, ROS overproduction, DNA oxidant damage, upregulation of HIF1a gene and aerobic glycolysis in healthy mammalian cells. Over-usage of antibiotics could contribute to tumorigenesis and neurodegeneration and aggravate existing mitochondria-associated diseases. Citation Format: Robert L. Elliott, Xianpeng Jiang. Antibiotics induce mitochondrial dysfunction, DNA damage and aerobic glycolysis of human mammary epithelia and fibroblast [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 3795.
Inhibition of transforming growth factor beta1 (TGFβ1) signaling increases radiosensitivity in breast cancer cell lines
Authors: Anupama Pal, Philippe Gascard, Shraddha Ravani, Mary Barcellos-Hoff
Journal: Cancer Research (2008)

423  Most human breast cancers are reported to be refractory to transforming growth factor beta 1 (TGFβ1) mediated growth regulation while producing large amounts of TGFβ1 (reviewed in Cancer Metastasis Rev 20 (1-2):133, 2001). Ionizing radiation (IR) activates TGFβ1 through a redox mechanism (Radiat Res 166:839-48, 2006) Our recent studies show that TGFβ1 depletion in irradiated epithelial cells compromises ataxia telengiectasia mutated (ATM) kinase activity and autophosphorylation, leading to reduced phosphorylation of critical DNA damage transducers γH2AX, Chk2, p53 and Rad17, abrogation of the cell cycle block and apoptosis (Cancer Res 66 (22):10861, 2006). Radiosensitivity is increased as a result in both Tgfβ1 null murine epithelial cells and non-malignant human epithelial cells in which TGFβ signaling is inhibited. Therefore, we hypothesized that TGFβ inhibition might increase clonogenic cell death in irradiated cancer cells. We first established the relative TGFβ1 sensitivity in 6 epithelial cell lines. Non-malignant MCF10A, breast cancer cell line Hs578T and lung carcinoma A549 were found to be responsive to TGFβ1 mediated growth inhibition while MCF7, MDAMB231 and T47D breast cancer cell lines were refractory. We next examined the status of TGFβ1 regulated transcription in these cell lines. 9 TGFβ1 responsive genes (FN1, WNT5A, CTGF, POSTN, KRT15, SERPINE1, CD24, CA2 and JAG1) were measured by RT-PCR with and without TGFβ or a small molecule inhibitor of the TGFβ type I receptor kinase (400 nM, Calbiochem, Cat. No. 616451). All cell lines showed a degree of active TGFβ1 transcriptional control as evidenced by regulation by TGFβ1 and reversal by the small molecule inhibitor. We then treated the cell lines with TGFβ1 type kinase I small molecule inhibitor 48 hr prior to, and 3 hr post, graded doses of radiation in serum-replacement media before determining clonogenic survival. Inhibiting TGFβ signaling in MCF10A, MCF7, MDAMB231, T47D and Hs578T cells significantly increased radiosensitivity as measured by clonogenic cell death. The lung carcinoma cell line A549 was more radioresistant after treatment with the TGFβ1 inhibitor. These results show that blocking TGFβ1 signaling renders most epithelial cancer cells more sensitive to radiation therapy regardless of their sensitivity to TGFβ1 mediated growth regulation. One rationale for blocking TGFβ in cancer is because it initiates a deleterious cytokine cascade that stimulates inflammation, stromal remodeling and metastasis; another is that TGFβ mediate fibrosis, which is a late tissue effect of cancer therapy. The use of TGFβ inhibitors during cancer therapy in combination with DNA damaging agents may well provide therapeutic advantage, as is demonstrated by increased radiosensitivity in breast cancer cells. Supported by the Department of Energy Low Dose Radiation Program.
Abstract 13575: Stem Cell Mobilization by Granulocyte-Colony Stimulating Factor Does not Increase Neointimal Volume or Non-Culprit Coronary Plaques After Sirolimus-Eluting Stent Implantation
Authors: Yo Iwata, Tadayuki Kadohira, Yoshihide Fujimoto, Yoshio Kobayashi
Journal: Circulation (2013)

Introduction: Stem cell mobilization by granulocyte-colony stimulating factor (G-CSF) attenuates the endothelial dysfunction in mechanically disrupted artery models. However, some clinical studies ...
Abstract 2589: A systematic study on the anti-tumor effect of combinatorial miRNA expression in hepatocellular carcinoma
Authors: Feng Xu, Man Tong, Stephanie Ma, Alan SL Wong
Journal: Cancer Research (2019)

Abstract Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer mortality worldwide. Treatment options for HCC patients are limited, especially for those with advanced HCC. Deregulation of microRNA (miRNA) expression is frequently observed in HCC, and many cellular targets of miRNAs are genetic regulators of tumorigenesis. In addition, miRNAs interact with each other to coordinate targeted gene expressions. The potential of devising combinatorial miRNA-based therapies for HCC, however, remains largely unexplored. Here, we performed high-throughput CombiGEM screens to characterize the anti-tumorigenic effect of combinatorial miRNA expression. We assembled a library of 1,849 pairwise combinations for 43 human miRNAs that are downregulated in HCC patients/cell lines, and identified four miRNA combinations that exert anti-proliferative effect in HCC cells both in vitro and in vivo. Further experiments are underway to validate and characterize the anti-tumor effect of these newly identified miRNA combinations in HCC. Citation Format: Feng Xu, Man Tong, Stephanie Ma, Alan SL Wong. A systematic study on the anti-tumor effect of combinatorial miRNA expression in hepatocellular 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 2589.
Abstract 511: An assessment of pre-conditioning regimens for optimal hCD34+ hematopoietic stem cell humanization of NSGTMmice
Authors: Caitlin S. Parello, Benjamin G. Cuiffo, Alexandria Kury, Kasey Reardon, Brett Van Dam, Sallyann Vu, Catarina Costa, Veronica Ritchie, Gavin Gagnon, Timothy Bateson, Samantha Rogers, Gregory D. Lyng, Stephen T. Sonis
Journal: Cancer Research (2019)

Abstract Humanized immune system (HIS) mice - immunocompromised Nod.Cg-Prkdcscid Il2rgtm1Wjl/SzJ animals in which the immune system has been humanized by the engraftment of CD34+ hematopoietic stem cells (HSC), peripheral blood mononuclear cells (PBMC), or other human cells/tissues - represent an important tool in pre-clinical oncology research. Here we investigated several pre-conditioning regimens (Busulfan pre-treatment or total body irradiation (TBI)) to determine which would yield maximum human leukocyte engraftment and lineage diversity. Animals were pre-treated either one or two doses of Busulfan (25 mg/kg) or varying doses of TBI (1.75, 2.0, or 2.5 Gy). One to two days later, animals received an adoptive transfer of native hCD34+ HSCs. Engraftment was monitored by flow cytometry assessment of peripheral blood four weeks after adoptive-transfer, and every four weeks thereafter through experiment termination at Week 16. Upon termination, spleen and bone-marrow were assessed for various leukocyte populations by flow cytometry. Animals undergoing pre-conditioning displayed increased human CD45+ cell engraftment at all timepoints as compared to animals without pre-conditioning, with animals treated with two doses of Busulfan demonstrating the greatest human CD45+ engraftment at all timepoints and reaching statistical significance at endpoint (vs no pre-conditioning; p&amp;lt;0.05). Diversity of leukocyte cell types (B cells, T cells, NK cells, and other hCD45+) in the bone-marrow was similar across pre-treatment paradigms, however for some lineages, representation in the bone-marrow was significantly altered between pre-conditioning type. The absolute number of T or B cells were increased in TBI and Busulfan treated groups, respectively, whereas NK cells as a percentage of singlets were increased in TBI treated groups. The diversity of leukocyte cell types in the spleen was likewise similar across groups, with B cells dominating. These data provide important insights into the utility of various pre-conditioning regimens for the humanization of NSG mice for pre-clinical oncology research, and demonstrate that the optimum pre-conditioning regimens should be selected based on treatment target. Citation Format: Caitlin S. Parello, Benjamin G. Cuiffo, Alexandria Kury, Kasey Reardon, Brett Van Dam, Sallyann Vu, Catarina Costa, Veronica Ritchie, Gavin Gagnon, Timothy Bateson, Samantha Rogers, Gregory D. Lyng, Stephen T. Sonis. An assessment of pre-conditioning regimens for optimal hCD34+ hematopoietic stem cell humanization of NSGTMmice [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 511.
The frequency of chromosomal abnormalities in AL amyloidosis and their impact on treatment response.
Authors: Hassan Yameen, Shayna Sarosiek, Vaishali Sanchorawala
Journal: Journal of Clinical Oncology (2019)

e19539 Background: Chromosomal abnormalities (CA) found in AL amyloidosis (AL) are similar to those found in multiple myeloma (MM.) However, t(11;14) has been reported more frequently in AL, anywhere from 30% - 50% in studies. It has been reported that the presence of t(11;14) confers a lower hematologic response rate with bortezomib-based therapy (BBT) and a better hematologic response rate with high dose melphalan and autologous stem cell transplantation (HDM/SCT). Methods: We performed a retrospective review of 307 newly diagnosed patients seen at our center between January 2013 and December 2017, for whom interphase fluorescent in-situ hybridization (iFISH) data, performed on bone marrow aspirate using standard MM FISH probes on enriched plasma cells after magnetic separation, were available. Patients who already had iFISH performed prior to their visit with us were also included. We collected data on the incidence of CA, first line treatment, and hematologic response to this treatment. Results: Of the 307 patients, CA were not detected in 37%. 21% had t(11;14), 25% had 13q deletion, 21% had IgH rearrangements with an undetermined partner chromosome, and 11% had 1q21 gain. In those for whom initial treatment and hematologic response data were available, in patients with t(11;14), hematologic complete response (CR) was achieved by 18% following HDM/SCT and 27% following BBT. For those with 1q21 gain, CR was achieved by 33% following HDM/SCT and 19% following BBT. In contrast, hematologic CR was achieved by 47% following HDM/SCT and 40% following BBT for those who had no detectable CA with iFISH. Conclusions: Our study shows a lower incidence of t(11;14) in AL compared to other studies. This may be partly explained by the high number of patients with IgH rearrangements with undetermined partner chromosomes, some of whom may indeed harbor t(11;14). Our study also did not show a better hematologic response rate with HDM/SCT in t(11;14) patients compared with BBT. Hematologic response rates were much better both with HDM/SCT and BBT for those with no detected CA compared to patients who had t(11;14) or 1q21 gain.
Abstract 1844: xCT promotes tumor formation in airway epithelial cells by activation MYC and WNT pathways
Authors: Xiangming Ji
Journal: Cancer Research (2019)

Abstract INTRODUCTION: Many tumors increase uptake and dependence on nutrients such as glucose, cysteine or glutamine. These basic observations on cancer cell metabolism have opened multiple new diagnostic and therapeutic avenues in cancer. Recent studies demonstrated that smoking can induce the expression of xCT (SLC7A11) in normal epithelial cells and cancer cells, suggesting that overexpression of xCT may support lung tumor progression. These basic observations on cancer cell metabolism have opened multiple new diagnostic and therapeutic avenues in cancer. Here, we investigated the function of SLC7A11 (xCT), a cystine/glutamate anti-porter, in the pathogenesis of lung cancer. Recently, we found xCT to be strongly overexpressed at the cell surface of lung cancers and began to investigate the mechanisms by which xCT may contribute to lung cancer progression. METHODS: We overexpressed the xCT in mutiple non-tumorgenic cell lines. These cell lines included 16HBE, BEAS2B, HBEC_KTR_P53_C7, and HEK293. We further investigated the role of xCT in cell proliferation, conly formation, and tumor formation in nude mice. Finally, we used RNAseq analysis to indentify the molecular mechanims associated with xCT expression in HEK293 cells. RESULTS: Our results shows that xCT overexpression transformed the normal airway epithelium cell lines (HBEC3_KTR_P53_C7). The overexpression of xCT in HBEC_KTR_P53C7 induced colony formation in soft agar and promoted cell proliferation. In addition, we found overexpression of xCT reprogrammed multiple metabolic pathways such as glycolysis, glutaminolysis, and pentose phosphate pathway. In addition, we found overexpression of xCT could transform non-tumorigenic cell line HBEC_KTR_P53_C7 to tumor-formation cell line. Our RNAseq data indicated that this transformation is enriched in MYC and WNT pathway. CONCLUSION: Our results demonstrate that xCT is highly expressed in a subset of NSCLCs. The induction of xCT in transformed aiway epithelial cells causes tumor formation in nude mice. The mechanism of malignant transformation involves the Warburg effect. Further investigation into the mechanisms of transformation may help in answering fundamental questions pertaining to how glutamate/cystine exchange contributes to lung cancer development and progression and also in establishing xCT as a potential novel therapeutic target in lung cancer. Key words: Non-small cell lung cancer, amino acid transporters, metabolic reprogramming Note: This abstract was not presented at the meeting. Citation Format: Xiangming Ji. xCT promotes tumor formation in airway epithelial cells by activation MYC and WNT pathways [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 1844.
Abstract 1141: Preclinical analysis of biodistribution and PET imaging of a zirconium-89 labeled PSMA-targeted antibody-chelator conjugate
Authors: Stefanie Hammer, Sabine Zitzmann-Kolbe, Felix Oden, Joerg Jannsen, Eva Bickel, Andre Mueller, Lothar Everz, Urs B. Hagemann, Jenny Karlsson, Olav B. Ryan, Hartwig Hennekes, Patricia E. Cole, Dominik Mumberg
Journal: Cancer Research (2019)

Abstract The PSMA targeted thorium-227 conjugate PSMA-TTC (BAY 2315497) is a targeted alpha therapy approach for metastatic castration resistant prostate cancer that has shown strong anti-tumor activity in PSMA-positive prostate cancer models (Hammer et al. AACR 2017/2018/2019). PSMA-TTC consists of a fully human IgG1 PSMA-targeted antibody covalently linked to a 3,2-HOPO chelator moiety, stably complexing the alpha emitter thorium-227. As this chelator can also complex zirconium-89, positron emission tomography (PET) imaging using the zirconium-89 labeled variant of the PSMA antibody-chelator conjugate could support clinical development of PSMA-TTC by enabling monitoring of organ distribution. Herein, we describe radiolabeling of the PSMA antibody-chelator conjugate with zirconium-89 and its quality control using bioanalytical assays. In addition, the zirconium-89 labeled PSMA antibody-chelator conjugate was injected into mice bearing LNCaP xenograft tumors and biodistribution was assessed by measurement of radioactivity in tumor and organs as well as PET imaging at different time points after injection. The PSMA antibody-chelator conjugate was successfully labeled with zirconium-89 at high yield, purity and specific activity. Target binding was confirmed by determination of the immunoreactive fraction. Biodistribution experiments revealed high, long lasting uptake of zirconium-89 in PSMA-positive LNCaP tumors after single injection of the zirconium-89 labeled conjugate. An uptake of 40-50% of the injected dose per gram of tumor was measured at 24, 48, 72, 168 and 240h after injection. The PET images showed that the zirconium-89 labeled PSMA antibody-chelator conjugate provided an excellent image contrast for the delineation of LNCaP xenografts between 48 and 168 h after administration. Other organs showed only very little background and tumor-to-heart ratio was greater than 10 when PET imaging was performed between 48 and 168 h after injection. These results indicate that the zirconium-89 labeled PSMA antibody-chelator conjugate shows promise for PET imaging studies. These properties may allow its use to support clinical development of PSMA-TTC. Citation Format: Stefanie Hammer, Sabine Zitzmann-Kolbe, Felix Oden, Joerg Jannsen, Eva Bickel, Andre Mueller, Lothar Everz, Urs B. Hagemann, Jenny Karlsson, Olav B. Ryan, Hartwig Hennekes, Patricia E. Cole, Dominik Mumberg. Preclinical analysis of biodistribution and PET imaging of a zirconium-89 labeled PSMA-targeted antibody-chelator conjugate [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 1141.