bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epigenetic regulation of the Birc5 promoter explains mechanism of action of YM‐155 in synovial sarcoma
Authors: Luelling Sarah , Mika Aleksander , Heyneman Alexandra , Parkinson Neil , Barrott Jared 
Published: June 2021

YM‐155 is an anti‐cancer therapy that has advanced into 11 different human clinical trials to treat various cancers. This apoptosis‐inducing therapy indirectly affects the protein levels of Survivin (Gene: Birc5), but the molecular underpinnings of the mechanism remain largely unknown. Synovial sarcoma is another cancer with high protein expression of Survivin. We investigated whether YM‐155 would be a viable therapeutic option to treat synovial sarcoma. We, therefore, applied YM‐155 therapy to human synovial sarcoma cell lines and a genetically engineered mouse model of synovial sarcoma. We discovered that YM‐155 exhibited nanomolar potency against human synovial sarcoma cell lines and the treated mice with synovial sarcoma demonstrated a 50% reduction in tumor volume compared to control treated mice. We further investigated the mechanism of action of YM‐155 by looking at the change of modifications of the histone tails that were near the Birc5 promoter. Using chomatin immunoprecipitation (ChIP) we discovered that the histone epigenetic marks of H3K27 for the Birc5 promoter changed upon YM‐155 treatment. H3K27me3 increased whereas the H3K27ac decreased, highlighting the decrease of the protein Survivin occurs through epigenetic silencing of the gene's promoter. The treatment of YM‐155 was accompanied by an increase in NFkB protein expression, which indicates an attempt of the cell to initiate a positive feedback due to the decrease in Survivin expression. This combination of molecular events eventually resulted in Caspace 3/7/8 upregulation and death of the sarcoma cells.Support or Funding InformationAlex's Lemonade StandIdaho State University Start UpThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
XRN2 Depletion is Synthetic Lethal with PARP1 Inhibition
Authors: Pay Louise , Motea Edward E , Patidar Praveen , Morales Julio C , Singh Naveen M , Khandelwal Megha , Ogas Talysa , Zhou Yunyun , Fattah Farjana J , Xie Yang , Boothman David A 
Published: June 2021

Persistent R‐loops (RNA‐DNA hybrids with a displaced single‐stranded DNA) create DNA damage and lead to genomic instability. The 5’‐3’‐exoribonuclease 2 (XRN2) degrades RNA to resolve R‐loops and promotes transcription termination. Previously, XRN2 was implicated in DNA double strand break (DSB) repair and in resolving replication stress. XRN2 function in DSB repair is not fully understood. We hypothesize that XRN2 plays a critical role in multiple DNA repair pathways. Here, using tandem affinity purification‐mass spectrometry, bioinformatics, and biochemical approaches, we found that XRN2 associates with proteins involved in DNA repair/replication (Ku70‐Ku80, DNA‐PKcs, PARP1, MCM2‐7, PCNA, RPA1), and RNA metabolism (RNA helicases, PRP19, p54(nrb), splicing factors). Novel major pathways linked to XRN2 include cell cycle control of chromosomal replication and DSB repair by non‐homologous end joining. Investigating the biological implications of these interactions led us to discover that XRN2 depletion compromised cell survival after additional knockdown of specific DNA repair proteins, including PARP1. XRN2‐deficient cells also showed enhanced PARP1 activity. Consistent with concurrent depletion of XRN2 and PARP1 promoting cell death, XRN2‐deficient fibroblast and lung cancer cells also demonstrated sensitivity to PARP1 inhibition. The XRN2 alterations (mutations, copy number/expression changes) are frequent in cancers. Thus, PARP1 inhibition could target cancers exhibiting XRN2 functional loss. Collectively, our data suggest XRN2's association with novel protein partners and unravel synthetic lethality between XRN2 loss and PARP1 inhibition.Support or Funding InformationThis work was largely supported by the National Institutes of Health/National Cancer Institute (NCI/NIH) [R01 CA139217] to D.A.B, a minority supplement [R01 CA139217‐05S1] and the Cancer Biology Training Grant T32CA124334‐06 to E.A.M. (PI: Dr. Jerry Shay), Simmons Comprehensive Cancer Center, UT Southwestern. This work was also supported by grant 5P30CA142543, NCI/NIH to the UT Southwestern Proteomics Core. The UT Southwestern Proteomics Core was also supported, in part, by a grant from the Cancer Prevention and Research Institute of Texas [CPRIT, RP1206130] to Dr. Hamid Mirzaei. Funding for open access charges was from NCI/NIH CA139217 to D.A.B. Research reported in this study was also supported by the UT Southwestern CCSG grant 5P30CA142543 from the NCI/NIH.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Proteasome Inhibition Increases Interleukin‐8 Expression in Triple Negative Breast Cancer Cells, Resulting in Their Increased Survival, Proliferation, and Migration
Authors: Uddin Mohammad , Zou Yue , Gaire Bijaya , Padmanabhan Sveta , Vancurova Ivana 
Published: June 2021

Interleukin‐8 (IL‐8, CXCL8) is a pro‐inflammatory and pro‐angiogenic chemokine that stimulates cancer progression by inducing tumor cell proliferation, survival, and migration. IL‐8 expression is increased in many types of advanced cancers, including triple negative breast cancer (TNBC), and correlates with poor prognosis. Because no targeted therapies are currently available, and majority of TNBC patients initially responding to cytotoxic chemotherapy become drug‐resistant, development of novel therapeutic strategies is essential. Proteasome inhibition by Bortezomib (BZ; Velcade; PS‐341) and Carfilzomib (CZ), developed for its ability to inhibit transcription of NFκB‐dependent anti‐apoptotic genes, has been effective in treating hematological malignancies. By contrast, as single agents, proteasome inhibitors (PI) have failed to show a significant clinical activity in solid tumors, including TNBC, but the mechanisms are not fully understood. Here, we demonstrate that proteasome inhibition increases expression of IL‐8, resulting in increased survival, proliferation, and migration of TNBC cells. The induced IL‐8 expression is mediated by IkB kinase (IKK), and associated with an increased nuclear accumulation of p65 NFκB, and IKK‐dependent p65 recruitment to IL‐8 promoter. Inhibition of IKK activity significantly decreases proliferation, migration, and invasion of BZ‐treated TNBC cells. These results are the first to show that proteasome inhibition increases IL‐8 signaling in TNBC cells, suggesting that targeting IKK activity might increase PI effectiveness in TNBC treatment.Support or Funding InformationSponsor: Dr. Ivana Vancurova (ASBMB member ID: 32743) Funding : NIH CA202775 grant (to Dr. Ivana Vancurova)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Combinatorial use of Lovastatin and FTI‐277 to alter Ras membrane association in A375 melanoma cells
Authors: Vagher Bay Lea 
Published: June 2021

In 2018, 9,000 of those people will die from melanoma (American Cancer Society, 2018). In melanoma like many cancers, a mutation in the Ras protein has been implicated in excessive cell proliferation. A farnesyl transferase inhibitor, FTI‐277, has shown the ability to lower Ras membrane association by disrupting Ras prenylation. Additionally, Lovastatin, a cholesterol lowering drug, is associated with decreased Ras membrane association. Unprenylated Ras cannot attached to the cell membrane or initiate signals in downstream effector proteins. Previous studies have shown that these two drugs cannot kill melanoma tumors individually, but the combinatorial effects have not been examined. We hypothesize that FTI‐277 will be a more potent inhibitor of Ras prenylation/activation than Lovastatin due to Lovastatin's high cytotoxicity. A metastatic melanoma cell line (A375) was treated and Ras prenylation and membrane association examined using immunofluorescence. Flow cytometry showed that the minimum concentration of 10 mM of each drug individually and in combination did not result in more than 30% cell death. Results showed that high concentrations of both drugs induced cell toxicity and at 10 mM Lovastatin was more cytotoxic than FTI‐277 (mean= 30.67%, 10.69% respectively, p=0.017). Cell image analysis showed that the average corrected total cell fluorescence for individual treatment with each drug was significantly lower than both the vehicle control and treatment with both drugs (p<0.05). Together this shows that treatment with these drugs is efficacious for melanoma due to their abilities to induce apoptosis and alter Ras membrane association.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sensitization of Anti‐EGFR/HER2 Targeted Therapy Resistance in Breast Cancer Cells by MiRNA Manipulation
Authors: Vigo‐Morales Paula Rocío , Borrero‐Garcia Luis Daniel , Del Mar Maldonado Maria , Dharmawardhane Suranganie 
Published: June 2021

The aim of this study is to explore the resistance mechanisms to anti‐epidermal growth factor receptor (EGFR) and anti‐human epidermal growth factor receptor (HER2) targeted therapies in breast cancer (BC). Previous studies have implicated the microRNA (miR)‐200 family in maintenance of the epithelial phenotype and sensitivity to EGFR targeted therapies and miR‐221/222 have been associated with epithelial to mesenchymal transition (EMT), tumor progression and therapy resistance. To investigate mechanisms of EGFR/HER2 therapy resistance in breast cancer, therapy resistant variants of the therapy sensitive SKBR3 human breast cancer cell line were created by exposure to different concentrations of the EGFR/HER2 inhibitors lapatinib and gefitinib. Characterization of therapy sensitive and resistant variants of SKBR3 demonstrated that miR‐200a is downregulated while miR‐221 and miR‐222 are overexpressed in the therapy resistant cells. Therefore, the current objective is to validate the role of these miRNAs in therapy resistance. The hypothesis is that re‐expression of miR‐200a and downregulation of miR‐221/222 will help overcome therapy resistance to EGFR/HER2 targeted therapy. Therefore, we re‐expressed miR‐200a ectopically in the therapy resistant and sensitive cells using a lentiviral vector containing miR‐200a, or a control vector. MiR‐221/222 inhibition was achieved by expressing anti‐miR‐221/222 or control inhibitors. MTT assays were used to determine the IC50s for cell viability. Both SKBR3 parental and lapatinib resistant variants with ectopic expression of miR‐200a were more sensitive to lapatinib treatment as shown by a decrease in the IC50 when treated with lapatinib. Therapy sensitive and resistant cell lines also demonstrated a decrease in cell viability when miR‐221 or miR‐222 was downregulated using miRNA inhibitors. In conclusion, overexpression of miR‐200a or downregulation of miR‐ 221/222 family reduces the malignancy of SKBR3 parental cell lines and sensitizes EGFR/HER2 therapy resistant cells. These results suggest that manipulation of miR‐200a, miR‐221 and miR‐222 can be used as therapeutic strategies in combination with HER2/EGFR therapy to reduce cancer malignancy and therapy resistance.Support or Funding InformationThis work was supported by grants from NIH/NIGMS SC3GM094824 to SD, RCMI Programs G12RR03051 to UPR MSC, MBRS Program RISE (R25GM061838) to LDB and MM, and Bright Cure Program (U54) University of Puerto Rico/MD Anderson Cancer Center to PRV.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Antimetastatic potential of Atovaquone against triple negative breast cancer: Involvement of the integrin‐FAK‐Src pathway
Authors: Gupta Nehal , Srivastava Sanjay 
Published: June 2021

Triple negative breast cancer (TNBC) is considered to be the most aggressive and malignant neoplasm and is highly metastatic in nature. Metastatic TNBC is difficult to treat and thus leads to poor patient survival. Death of about 90% breast cancer patients is due to metastasis of primary tumor to distant sites. In the current study, we investigated the anti‐metastatic potential of atovaquone, a protozoal drug prescribed for Pneumocystis pneumonia. We show that atovaquone induced apoptosis and reduced the survival of several aggressive metastatic TNBC cell lines including few metastatic patient derived cells. The IC50 of atovaquone was around 11–18 μM in the breast cancer cell lines tested. Additionally, atovaquone treatment significantly reduced the expression of integrinα6, integrin β4, FAK, Src, and Vimentin in MDA‐MB‐231, HCC1806 and 4T1 cells after 72 hours of treatment. In order to study the efficacy of atovaquone in preventing metastasis of breast tumor cells to brain and lungs, we performed three in vivo experiments. We demonstrate that oral administration of 50mg/kg of atovaquone suppressed MDA‐MB‐231 breast tumor growth by 90% in lungs in an intravenous metastatic tumor model. Further anti metastatic effect of atovaquone was determined by intracardiac injection of 4T1‐luc breast tumor cells into the left ventricle of mouse heart. Once breast cancer cells lodged in the brain, mice were treated with 50 mg/kg atovaquone for 15 days. Our results show that atovaquone treatment suppressed the growth of metastatic tumors in brain by 30%. In this model, we also observed 70% and 50% reduced metastasis of breast tumors in lungs and liver, respectively, in atovaquone treated group when compared with control. In intracranial model, the growth of HCC1806‐luc brain tumors in atovaquone treated mice was about 55% less than that of control. Angiogenesis is one of the hallmarks of cancer and plays crucial role in metastasis. Interestingly, we observed reduced levels of VEGF in the cells treated with atovaquone. In‐vivo angiogenesis was evaluated by performing matrigel plug assay in mice. Our results showed reduced angiogenesis in atovaquone treated mice group. Atovaquone treated tumors from these in‐vivo models exhibited reduced metastatic markers and increased apoptosis. Taken together, our results indicate the anti‐metastatic effects of atovaquone in‐vitro and in‐vivo in various breast tumor metastasis models by inhibiting angiogenesis and integrin signaling and provides the rationale for further clinical investigation of atovaquone for breast cancer metastasis.Support or Funding InformationThis work is supported in part by RO1 grant CA129038, awarded by National Cancer Institute, (NIH) to Sanjay K. Srivastava.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Determining the role of Pal in Escherichia coli sepsis
Authors: Gallardo Leslie , Bauer Morgan , Pannullo Nicole , Michel Lea Vacca 
Published: June 2021

Sepsis, a life‐threatening clinical condition affecting more than 1.5 million Americans per year, is defined as an over‐exuberant immune response to infection. Currently, sepsis is the leading cause of death in U.S. hospitals, and the incidence of sepsis caused by Gram‐negative bacteria, such as Escherichia coli (E. coli), has been steadily increasing since the late 1990's. While the detailed mechanism of sepsis is not fully understood, several bacterial components are thought to contribute to the hyper‐inflammatory response in humans. Past studies suggest that one E. coli lipoprotein, Peptidoglycan‐Associated Lipoprotein (Pal), may contribute to inflammation and the pathogenesis of sepsis. This work describes our efforts to elucidate the role of Pal in E. coli sepsis and the effect of antibiotics in Pal release from E. coli using a mouse model of sepsis. Our preliminary results corroborate the hypothesis that Pal releases from E. coli and contributes to inflammation and sepsis.Support or Funding InformationRochester Institute of TechnologyThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Characterization of non‐C2 symmetric salen ligands as novel antimicrobial and antifungal agents
Authors: Allgood Cory W. , Wolyniak Michael J , Deifel Nicholas P 
Published: June 2021

The importance of salen ligands in homogeneous catalysis and material chemistry/biochemistry has unambiguously been demonstrated in procedures that include the synthesis of C2‐symmetrical complexes that are used as catalysts for many organic conversions with industrial applications. Of late, research on salen ligands has turned to the potential for non‐C2 symmetric ligands to act asantimicrobials and antifungals. As drug‐resistant microbes become a larger threat to public health, novel compounds like non‐C2 symmetric salen ligands could be an invaluable resource for disease control.Here, a practical synthesis of a non‐C2 symmetric salen ligand is described using a 1:1:1 molar ratio of phenylenediamine and two different salicylaldehyde's which can be important in testing catalytic properties along with antimicrobial activity. Specially, we have built a non‐C2 symmetric ligand using varying R groups and metal complexes and have characterized the resultant product using 13C‐ NMR, 1H‐NMR, infrared spectroscopy, and gas chromatography‐mass spectroscopy. Current research focuses on the use of metal ions such as iron and zinc in the formation of efficient and cost‐effective novel antimicrobial and antifungal compounds that can be tested using Kirby‐Bauer analyses.Support or Funding InformationHampden‐Sydney College Office of Undergraduate ResearchThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Structure‐activity relationship of a novel Staphylococcus aureus biofilm formation inhibitor
Authors: Shah Ashna , Baker Nnamdi , Loving Danielle , Hensel Linda , Goode David 
Published: June 2021

Ideal biofilm inhibitors would not affect the growth of bacteria, in general, but would be specific for inhibiting reception of the signals to initiate biofilm formation. In this manner, the inhibitor would not affect the growth of normal flora that are imperative for the health of the host. Compounds that resemble biofilm signaling molecules have the potential to competitively inhibit the receptors from receiving signals. Over 400 novel compounds were synthesized and tested by undergraduate students in a sophomore integrated biology and organic chemistry classroom setting. Compounds that demonstrated a statistically significant inhibition of biofilm formation and that had no bacteriostatic or bactericidal activity in one or more of five species of bacteria (Streptococcus mutans, Escherichia coli, Bacillus subtilus, Staphylococcus aureus, and Pseudomonas aeruginosa) in the hands of the undergraduates underwent further testing. Confirmed hits were further tested for a dose response. Compound Tyr‐69 was a promising hit compound with specific inhibition of Staphylococcus aureus biofilms. A structure‐activity analysis was pursued via synthesis and dose response assays.Support or Funding InformationThis work is supported by the Biology and Chemistry Departments of Mercer University as well as the Mercer University Quality Enhancement Plan: Research that Reaches Out.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Glycogen phosphorylase inhibition activates intrinsic apoptosis pathway and potentiates multi‐kinase inhibitors in liver cancer cells
Authors: Barot Shrikant , Abo‐Ali Ehab M , Zhou Daisy , Palaguachi Christian , Dukhande Vikas D 
Published: June 2021

Hepatocellular carcinoma (HCC) is one of the leading cancers in terms of incidence and mortality. There are fewer chemotherapies with HCC with a low survival rate. One of the prominent features of cancer is metabolic reprogramming and thus metabolic proteins are viable targets for cancer treatment. Glycogen is a polymer of glucose, which acts as a reservoir of energy in mammalian cells. The levels of glycogen have been found to correlate with biological processes in cancer cells, however, the role of glycogen metabolism in carcinogenesis, cancer cell growth, metastasis, and chemoresistance is not completely understood. Thus, we studied the cellular processes involved in the inhibition of glycogen metabolism in HCC. Pharmacological inhibition of glycogen phosphorylase (GP) by CP‐91149, a rate‐limiting enzyme in glycogen catabolism, led to a decrease in HepG2 viability. GP inhibition induced the intrinsic apoptosis pathway causing HepG2 cell death. This process was accompanied by mitochondrial dysfunction and autophagic adaptations, whereas endoplasmic reticulum stress, necrosis, and necroptosis were not involved. In addition, GP inhibition potentiated the effects of the multi‐kinase inhibitors sorafenib and regorafenib, which are key drugs in advanced‐stage HCC therapy. Our study provides mechanistic insights into cell death by perturbations of glycogen metabolism and identifies GP inhibition as a potential cancer pharmacotherapy target.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Heme Interaction with the Pyruvate Dehydrogenase Complex: A Novel Strategy to Promote Hypoxic Survival
Authors: Lynch John Allan , Fukuda Yu , Krishnamurthy Partha , Wijaya Juwina , Wang Yao , Herras Andras , Cheepala Satish , Bao Ju , Nourse Amanda , Milasta Sandra , Neale Geoffrey , Zheng Jie , Green Douglas , Chi Hongbo , Schuetz John 
Published: June 2021

Heme is an important regulator of biological processes, but an unresolved question remains, can heme regulate the switch between glycolysis and mitochondrial oxidation in mammalian cells? Here we show that ABCB6, a member of the ATP‐binding cassette (ABC) family and an activator of heme synthesis facilitates a heme dependent metabolic transition between mitochondrial oxidative phosphorylation and glycolytic metabolism. ABCB6 is upregulated by the Hif‐1α pathway and mimicking this, overexpression of ABCB6 primarily increased mitochondrial heme, reduced pyruvate‐fueled mitochondrial oxygen consumption and increased hypoxic survival. Suppression of heme synthesis abolished this hypoxic survival advantage. Deletion of ABCB6 increased mitochondrial oxygen consumption in the inherently hypoxic double‐negative thymocytes. We hypothesized that pyruvate dehydrogenase (PDH) activity was suppressed by heme and directly demonstrated that heme potently inhibited PDH activity. Hemin‐agarose affinity chromatography revealed that only one subunit of the multimeric PDH complex, PDHA1, is bound to heme. Mutagenesis of PDHA1 suggested that the heme binding site was distinct from the substrate binding site, a finding consistent with heme inhibiting PDH non‐competitively. Heme binding to PDHA1 resulted in its dissociation from the PDH complex. PDHA1 dissociation was reversible, as dilution of heme containing PDH promoted reformation of the complex, which paralleled restoration of PDH activity. These findings reveal a new relationship between heme production and the ability to metabolically switch from pyruvate oxidation in the mitochondria to its glycolytic conversion to lactate.Support or Funding InformationThis work was supported by NIH and by the ALSAC.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.