Temesgen Samuel - Academia.edu (original) (raw)

Papers by Temesgen Samuel

Research paper thumbnail of Prognostic and Predictive Biomarkers for Colorectal Cancer

Biomarkers in Cancer Screening and Early Detection

Research paper thumbnail of cIAP1 Localizes to the Nuclear Compartment and Modulates the Cell Cycle

Cancer Research

We explored the location and function of the human cIAP1 protein, a member of the inhibitor of ap... more We explored the location and function of the human cIAP1 protein, a member of the inhibitor of apoptosis protein (IAP) family. Unlike family member X-linked IAP (XIAP), which was predominantly cytoplasmic, the cIAP1 protein localized almost exclusively to nuclei in cells, as determined by immunofluorescence microscopy and subcellular fractionation methods. Interestingly, apoptotic stimuli induced nuclear export of cIAP1, which was blocked by a chemical caspase inhibitor. In dividing cells, cIAP1 was released into the cytosol early in mitosis, then reaccumulated in nuclei in late anaphase and in telophase, with the exception of a pool of cIAP1 that associated with the midbody. Survivin, another IAP family member, and cIAP1 were both localized on midbody microtubules at telophase, and also interacted with each other during mitosis. Cells stably overexpressing cIAP1 accumulated in G2-M phase and grew slower than control-transfected cells. These cIAP1-overexpressing cells also exhibited...

Research paper thumbnail of Molecular phylogeny of coronaviruses and host receptors among domestic and close-contact animals reveals subgenome-level conservation, crossover, and divergence

BMC Veterinary Research

Background Coronaviruses have the potential to cross species barriers. To learn the molecular int... more Background Coronaviruses have the potential to cross species barriers. To learn the molecular intersections among the most common coronaviruses of domestic and close-contact animals, we analyzed representative coronavirus genera infecting mouse, rat, rabbit, dog, cat, cattle, white-tailed deer, swine, ferret, mink, alpaca, Rhinolophus bat, dolphin, whale, chicken, duck and turkey hosts; reference or complete genome sequences were available for most of these coronavirus genera. Protein sequence alignments and phylogenetic trees were built for the spike (S), envelope (E), membrane (M) and nucleocapsid (N) proteins. The host receptors and enzymes aminopeptidase N (APN), angiotensin converting enzyme 2 (ACE2), sialic acid synthase (SAS), transmembrane serine protease 2 (TMPRSS2), dipeptidyl peptidase 4 (DPP4), cathepsin L (and its analogs) and furin were also compared. Results Overall, the S, E, M, and N proteins segregated according to their viral genera (α, β, or γ), but the S protein...

Research paper thumbnail of Loss of Neuroligin 4X Induces an Intrinsic Innate Immune Response in TNBC

BackgroundImmune checkpoint blockade therapies, which act on T cell inhibitory receptors, includi... more BackgroundImmune checkpoint blockade therapies, which act on T cell inhibitory receptors, including CTLA-4 and PD-1, induce durable responses across diverse cancers. However, most patients do not respond to these therapies, and initially responsive cancers may relapse. Identifying molecular mechanisms that influence therapeutic responses and resistance is critical to realize the full therapeutic potential of immune checkpoint inhibitors. The presence of immune infiltrates in the tumor microenvironment is associated with positive outcomes in breast cancer, specifically in triple-negative breast cancer (TNBC). The underlying mechanisms driving this response are unclear. We have previously identified Neuroligin 4X (NLGN4X) as a protein expressed in TNBC.MethodsBioinformatic analysis was used for pathway analysis of TCGA TNBC patient dataset. Immunohistochemistry was performed on breast cancer tissue microarray for NLGN4X protein expression. RNA-seq was performed on MDA-MB-231 breast ca...

Research paper thumbnail of Development of Drug Delivery System Using Bio based Calcium carbonate Nanoparticles

5-Fluorouracil (5-FU) is a well known anti-cancer drug which is commonly used for several cancer ... more 5-Fluorouracil (5-FU) is a well known anti-cancer drug which is commonly used for several cancer therapies. 5-FU is administered subcutaneously or intravenously to patients, and these results in low patient compliance. A better way to administer this 5-FU is in immediate need [1-2]. Calcium carbonate (CaCO3) nanoparticles are highly porous, biocompatible, biodegradable, and have pH-sensitive properties. These properties make CaCO3 nanoparticles one of the best candidates for a drug delivery system specially for 5-FU. In this research, the CaCO3 nanoparticles were derived from egg shells using sonochemical and mechanochemical methods. The glycerol and acetic acid were used as solvents in this process to avoid other toxic solvents. These nanoparticles were loaded with 5-FU drug by physical absorption. Oral administration of 5-FU can be beneficial to colon cancer patients as it could not only reduce the pain resulting in better compliance, but also mimic the physiological fate of 5-FU....

Research paper thumbnail of Synthesis and Characterization of PVP/CaCO3-Ag Blend Hydrogel by Gamma Irradiation: Study of Drug Delivery System and Antimicrobial Activity

The Minerals, Metals & Materials Series, 2019

Chronic wounds are skin injuries with failed healing. They have become a public health problem th... more Chronic wounds are skin injuries with failed healing. They have become a public health problem that affects more than 2% of the population and the presence of bacteria resistances difficult of treatment. Pseudomonas aeruginosa is opportunist pathogens and the treatment is difficult and requires a long period of treatment. Hydrogels are structure polymeric tridimensional and biocompatible. They have been used as a controlled delivery system for treatment of topic infection. Studies have reported calcium carbonate and silver ion can improve the mechanical properties and biocide activity of hydrogel. Here in this study, hydrogels loaded CaCO3-Ag were prepared using poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), agar, calcium carbonate, silver nitrate followed gamma irradiation with 25 kGy dose. The gel fraction, behavior swelling and biocide action against P. aeruginosa was investigated. The degree of swelling of the hydrogel loaded CaCO3-Ag was 12% higher than the unloaded and ...

Research paper thumbnail of Eggshell Based Nano-Engineered Hydroxyapatite and Poly(lactic) Acid Electrospun Fibers as Potential Tissue Scaffold

International Journal of Biomaterials, 2019

Nanocomposite electrospun fibers were fabricated from poly(lactic) acid (PLA) and needle-like hyd... more Nanocomposite electrospun fibers were fabricated from poly(lactic) acid (PLA) and needle-like hydroxyapatite nanoparticles made from eggshells. The X-ray diffraction spectrum and the scanning electron micrograph showed that the hydroxyapatite particles are highly crystalline and are needle-liked in shape with diameters between 10 and 20 nm and lengths ranging from 100 to 200 nm. The microstructural, thermal, and mechanical properties of the electrospun fibers were characterized using scanning electron microscope (SEM), thermogravimetric analysis (TGA), dynamic scanning calorimetry (DSC), and tensile testing techniques. The SEM study showed that both pristine and PLA/EnHA fibers surfaces exhibited numerous pores and rough edges suitable for cell attachment. The presence of the rod-liked EnHA particles was found to increase thermal and mechanical properties of PLA fibers relative to pristine PLA fibers. The confocal optical images showed that osteoblast cells were found to attach on d...

Research paper thumbnail of Camptothecin Induces PD-L1 and Immunomodulatory Cytokines in Colon Cancer Cells

Medicines, 2019

Background: Immunotherapy has changed the options for the treatment of various cancer types, but ... more Background: Immunotherapy has changed the options for the treatment of various cancer types, but not colon cancer. Current checkpoint blockade approaches are ineffective in a large proportion of colon cancer cases, necessitating studies to elucidate its mechanisms and to identify new targets and strategies against it. Methods: Here, we examined Programmed Death-Ligand 1(PD-L1), cytokine and receptor responses of colon cancer cells exposed to camptothecin (CPT), a clinically used topoisomerase inhibitor. Colon cancer cells were treated with CPT at concentrations of up to 10 µM, and the expressions of PD-L1 and immunoregulatory cytokine genes and receptors were analyzed. Results: PD-L1, a current immunotherapy target for various cancers, was shown to be upregulated in colon cancer cells independent of the cellular p53 status. In metastasis-derived SW620 cells, CPT most extensively upregulated cytokines with T-cell attraction or growth factor functions. Of those modulated genes, SPP1, ...

Research paper thumbnail of The Combination of Omega-3 Stearidonic Acid and Docetaxel Enhances Cell Death over Docetaxel Alone in Human Prostate Cancer Cells

Journal of Cancer, 2018

Background: Docetaxel (DOC), or Taxotere, is an anthracycline antibiotic used to treat multiple t... more Background: Docetaxel (DOC), or Taxotere, is an anthracycline antibiotic used to treat multiple types of cancer. It is a first-line chemotherapy treatment for patients with metastasized, hormone-resistant prostate cancer (PCa) or for patients with high-risk, localized PCa that could benefit from early chemotherapy treatment. Previously, we showed that stearidonic acid (SDA), an omega-3 fatty acid, enhances the cytotoxicity of doxorubicin (DOX) in human PCa cells. This observation suggests that PCa therapies using SDA and chemotherapeutic drugs in combination offer attractive possibilities for developing treatments that ameliorate toxic side effects of some commonly used chemotherapy drugs. Objectives: We used androgen-resistant PC3 and DU 145 cells derived from human prostate cancer to quantify the effects of combined SDA and DOC on proliferation/viability and on the production of pro-apoptotic caspases 9 and 3. We also compared the effects of SDA with those of BAY, a pharmacological inhibitor of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), in androgen-sensitive LNCaP cells. Finally, we qualitatively and quantitatively assessed the drug combination on androgen receptor (AR) and peroxisome proliferator-activated receptor gamma (PPARγ) expression in LNCaP and PC3 cells, respectively. Methods: The half maximal inhibitory concentration (IC50) and combination indices of SDA and DOC in PC3 and DU 145 cells were determined using the MTT cell viability assay. To quantify the effects of SDA and BAY on NF-ĸB activity, we used luciferase reporter assays in LNCaP cells that were stably transduced with lentiviral vectors carrying NF-ĸB response element sequence upstream of the luciferase gene sequence. AR and PPARγ expression were assessed by western blotting and immunocytochemistry. We considered caspase 9 and 3 cleavage to be apoptosis markers and determined the drug combination effect on the extent of that cleavage by western blot analysis. Results: The cytotoxic effects of DOC were synergistically enhanced by SDA when the two were added to DU145 and PC3 cell cultures. Combination index (CI) analyses based on the Chou-Talalay method and mass action law showed synergistic interaction with CI <1. SDA suppressed TNFα-induced NF-κB activity similarly to BAY. The SDA/DOC combination down regulated testosterone (T)-induced AR and troglitazone-induced PPARγ protein expression when compared to using the drugs singly. Similarly, the SDA/DOC combination induced caspase 9 and 3 production and cleavage suggesting apoptosis induction. Like our DOX studies, this work provides proof-of-concept for using SDA and DOC in combination to reduce the dose, and therefore the toxicity, of DOC and possibly increasing the survival benefit in DOC clinical translation studies.

Research paper thumbnail of Simultaneous Detection of Multiple Salmonella Serovars from Milk and Chicken Meat by Real-Time PCR Using Unique Genomic Target Regions

Journal of food protection, Jan 23, 2017

A novel genomic and plasmid target-based PCR platform was developed for the detection of Salmonel... more A novel genomic and plasmid target-based PCR platform was developed for the detection of Salmonella serovars Heidelberg, Dublin, Hadar, Kentucky, and Enteritidis. Unique genome loci were obtained through extensive genome mining of protein databases and comparative genomic analysis of these serovars. Assays targeting Salmonella serovars Hadar, Heidelberg, Kentucky, and Dublin had 100% specificity and sensitivity, whereas those for Salmonella Enteritidis had 97% specificity and 88% sensitivity. The limits of detection for Salmonella serovars Heidelberg, Kentucky, Hadar, Enteritidis, and Dublin were 12, 9, 40, 13, and 5,280 CFU, respectively. A sensitivity assay was also performed by using milk artificially inoculated with pooled Salmonella serovars, yielding a detection limit of 1 to10 CFU/25 mL of milk samples after enrichment. The minimum DNA detected using the multiplexed TaqMan assay was 75.8 fg (1.53 × 10 genomic equivalents [GE]) for Salmonella Heidelberg, 140.8 fg (2.8 × 10 GE)...

Research paper thumbnail of Effects of consumption of whole grape powder on basal NF-κB signaling and inflammatory cytokine secretion in a mouse model of inflammation

Journal of nutrition & intermediary metabolism, 2018

Dietary consumption of polyphenol-rich fruits, such as grapes, may reduce inflammation and potent... more Dietary consumption of polyphenol-rich fruits, such as grapes, may reduce inflammation and potentially prevent diseases linked to inflammation. Here, we used a genetically engineered murine model to measure Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) activity and pro-inflammatory cytokine secretion to test the hypothesis that oral consumption of whole grape formulation reduces inflammatory signaling in the body. NF-κB luciferase reporter mice were divided into two groups, one which was fed an experimental diet formulated with 4% (w/w) whole grape powder (WGP) or another which was fed a control diet formulated with 3.6% glucose/fructose (w/w) combination. Simulated inflammation was induced in the mice by intraperitoneal injection of lipopolysaccharide (LPS).imaging was used to determine the effect of each diet on NF-κB activity. We found that there were no significant differences in weight gain between the WGP and control diet groups. However, there was a s...

Research paper thumbnail of Bromoethylindole (BEI-9) redirects NF-κB signaling induced by camptothecin and TNFα to promote cell death in colon cancer cells

Apoptosis : an international journal on programmed cell death, 2017

Chemotherapeutic regimens containing camptothecin (CPT), 5-fluorouracil, and oxaliplatin are used... more Chemotherapeutic regimens containing camptothecin (CPT), 5-fluorouracil, and oxaliplatin are used to treat advanced colorectal cancer. We previously reported that an indole derivative, 3-(2-bromoethyl)indole (BEI-9), inhibited the proliferation of colon cancer cells and suppressed NF-κB activation. Here, we show that a combination of BEI-9 with either CPT or tumor necrosis factor alpha (TNFα) enhances cell death. Using colorectal cancer cells, we examined the activation of NF-κB by drugs, the potential of BEI-9 for inhibiting drug-induced NF-κB activation, and the enhancement of cell death by combination treatments. Cells were treated with the chemotherapeutic drugs alone or in combination with BEI-9. NF-κB activation, cell cycle profiles, DNA-damage response, markers of cell death signaling and targets of NF-κB were evaluated to determine the effects of single and co-treatments. The combination of BEI-9 with CPT or TNFα inhibited NF-κB activation and reduced the expression of NF-κB...

Research paper thumbnail of Nanoparticles for Detection, Diagnostics, and Targeting using Hyperspectral Imaging

Microscopy and Microanalysis, 2017

Novel and modified nanoparticles containing multiple inherent and specific functionalities make t... more Novel and modified nanoparticles containing multiple inherent and specific functionalities make them powerful tools in bioimaging, cancer targeting, cancer therapy, and microbial capture and detection. 1 For example, gold and iron oxide nanoparticles offer potential advantages in the bioimaging of cancer cells due to their respective strong absorption and scattering, and magnetic properties. 2 Several studies in the literature suggest the potency and efficiency of these nanoparticles in therapeutic applications. For example, per Alhalili Z. et al (2016), there was no observed significant decrease (P>0.05) in cell viability when TD47 cells are treated with gold nanoparticles (AuNPs) alone. 3 However, the same cells were significantly killed by the application of AuNPs chemically conjugated to Taxol, suggesting the potential of gold nanoparticles for efficient delivery of Taxol to breast cancer cells. Similarly, Ding R.L. (2017) reported the release of endostatin (ES) in a sustained manner in vitro that showed an excellent inhibitory effect on HUVECs proliferation and migration. 4 The study concluded that ES-NPs significantly improved the anticancer activity of ES by affecting angiogenesis. Despite similar developments in nanomaterial research, much remains to be done in terms of the characterization of the interaction between the cells and the drug loaded nanoparticles. In this study, we report the use of CytoViva Hyperspectral Imaging technology to identify cellular uptake of nanoparticles and to attempt to characterize (if any), the interaction between selected NPs and colon cancer cells.

Research paper thumbnail of Nanomaterial-based receptor conjugates for capture and rapid detection of Salmonella Enteritidis

Microscopy and Microanalysis, 2017

According to the Centers for Disease Control and Prevention (CDC), an estimated 1 in 6 Americans ... more According to the Centers for Disease Control and Prevention (CDC), an estimated 1 in 6 Americans become ill by consuming foods or beverages contaminated by disease causing pathogens each year [1]. Foodborne diseases have become a significant public health concern throughout the globe with an increase in incidence over the last two decades [2]. Salmonellosis is one of the most important bacterial diseases of food safety concern; and is caused primarily by Salmonella species such as Salmonella Enteritidis and Salmonella Typhimurium [3]. The World Health Organization (WHO) has shown statistics of tens of millions of new human cases and more than 100,000 deaths every year from individuals with symptoms that include fever, abdominal pain, diarrhea, nausea, and vomiting [3,4,5,6].

Research paper thumbnail of HM015k, a Novel Silybin Derivative, Multi-Targets Metastatic Ovarian Cancer Cells and Is Safe in Zebrafish Toxicity Studies

Frontiers in Pharmacology, 2017

This study was designed to determine the in vitro mechanisms by which the novel silybin derivativ... more This study was designed to determine the in vitro mechanisms by which the novel silybin derivative, (E)-3-(3-(benzyloxy) phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (HM015k or 15k), produces its anticancer efficacy in ovarian cancer cells. Compound 15k induced apoptosis in ovarian cancer cells in a time-dependent manner by significantly upregulating the expression of Bax and Bak and downregulating the expression of Bcl-2. Interestingly, 15k induced the cleavage of Bax p21 into its more efficacious cleaved form, Bax p18. In addition, caspase 3 and caspase 9 were cleaved to their active forms, inducing the cleavage of poly ADP ribose polymerase (PARP) and β-catenin. Furthermore, in OV2008 cells, 15k induced significant cleavage in nuclear β-catenin to primarily inactive fragments of lower molecular weight. Furthermore, 15k reversed the metastatic potential of OV2008 cells by inhibiting their migration and invasiveness. The mesenchymal phenotype in OV2008 was reversed by 15k, causing cells to be rounder with epithelial-like phenotypes. The 15k-induced reversal was further confirmed by significant upregulation of the E-cadherin expression, an epithelial marker, while N-cadherin, a mesenchymal marker, was downregulated in OV2008 cells. Compound 15k inhibited the expression of the oncogenic c-Myc protein, downregulated proteins DVL3 and DVL2 and significantly upregulated cyclin B1. Also, 15k significantly downregulated the expression levels of ABCG2 and ABCB1 transporters in resistant ABCG2 overexpressing H460/MX20 and resistant ABCB1 overexpressing MDCK/MDR1 cells, respectively. Finally, 15k was safe in zebrafish in vivo model at concentrations up to 10 µM and induced no major toxicities in cardiac, morphology and swimming position parameters. Overall, 15k is a multi-targeted inhibitor with efficacy against metastatic and resistant ovarian cancer. Future in vivo studies will be conducted to determine the efficacy of 15k in tumor-bearing animals.

Research paper thumbnail of Abstract 5910: Influence of 3D- cultured prostate cancer and stromal cells on drug response

Cancer Research, 2017

Background: Response to chemotherapeutic drugs presents a significant challenge to effective trea... more Background: Response to chemotherapeutic drugs presents a significant challenge to effective treatment of advanced prostate cancer. Exploration of therapeutic response has focused largely on the tumor cell. However, evidence suggests mechanisms that involve the tumor microenvironment mediate response to therapeutics. Therefore, it is imperative to mimic the in vivo tumor microenvironment, to bridge the gap between in vitro studies and the development of therapeutics. The concept of three-dimensional (3D) cell culture and co-culture of multiple cell types is critical to predict therapeutic efficacy and outcome. Thus, these studies sought to determine the distinct responses to anti-cancer drugs in 3D cell spheroids. Methods: In this study, we utilized metastatic prostate cancer cells (PC3) and fluorescently labeled prostate bone stromal cell line (HS27a) to generate tumor spheroids. Tumor spheroid viability was measured at 72 and 120 h using the CellTiter-Glo 3D assay after treatment ...

Research paper thumbnail of Polyphenolic Nutrients in Cancer Chemoprevention and Metastasis: Role of the Epithelial-to-Mesenchymal (EMT) Pathway

Nutrients, 2017

The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel targe... more The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel target in cancer prevention, metastasis, and resistance. The conversion of cells from an epithelial, adhesive state to a mesenchymal, motile state is one of the key events in the development of cancer metastasis. Polyphenols have been reported to be efficacious in the prevention of cancer and reversing cancer progression. Recently, the antimetastatic efficacy of polyphenols has been reported, thereby expanding the potential use of these compounds beyond chemoprevention. Polyphenols may affect EMT pathways, which are involved in cancer metastasis; for example, polyphenols increase the levels of epithelial markers, but downregulate the mesenchymal markers. Polyphenols also alter the level of expression and functionality of important proteins in other signaling pathways that control cellular mesenchymal characteristics. However, the specific proteins that are directly affected by polyphenols in these signaling pathways remain to be elucidated. The aim of this review is to analyze current evidence regarding the role of polyphenols in attenuating EMT-mediated cancer progression and metastasis. We also discuss the role of the most important polyphenol subclasses and members of the polyphenols in reversing metastasis and targeting EMT. Finally, limitations and future directions to improve our understanding in this field are discussed.

Research paper thumbnail of Nano-engineered eggshell-silver tailored co-polyester polymer blend film with antimicrobial properties

Journal of agricultural and food chemistry, Jan 16, 2017

In this study, the reinforcement effect of different proportions of eggshell/silver nanomaterial ... more In this study, the reinforcement effect of different proportions of eggshell/silver nanomaterial (ES-Ag) on structural and antimicrobial properties of 70/30 poly (butylene-co-adipate terephthalate)/polylactic acid (PBAT/PLA) immiscible blends were investigated. The ES-Ag was synthesized using a single step ball milling process, and characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). These results confirmed the existence of silver nanoparticles (Ag NPs) in the interstitial spaces of the eggshell particles. The thin films in this study were prepared using hot melt extrusion and 3D printing for mechanical and antimicrobial testing respectively. These films were also characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), XRD, tensile testing and antimicrobial analysis. It was found that the incorporation of ES-Ag (0.5-2.0 % content) compromi...

Research paper thumbnail of Molecular Biomarkers of Colorectal Cancer and Cancer Disparities: Current Status and Perspective

Current Colorectal Cancer Reports, 2016

This review provides updates on the efforts for the development of prognostic and predictive mark... more This review provides updates on the efforts for the development of prognostic and predictive markers in colorectal cancer based on the race/ethnicity of patients. Since the clinical consequences of genetic and molecular alterations differ with patient race and ethnicity, the usefulness of these molecular alterations as biomarkers needs to be evaluated in different racial/ ethnic groups. To accomplish personalized patient care, a combined analysis of multiple molecular alterations in DNA, RNA, microRNAs (miRNAs), metabolites, and proteins in a single test is

Research paper thumbnail of Abstract 3783: Co-treatment of metastasis-derived colon cancer cells with bromoethyl indole (BEI) enhances camptothecin or TNF alpha-induced cell death

Cancer Research, 2016

Colorectal cancer is still the third most deadly cancer in the United States. Currently, there ar... more Colorectal cancer is still the third most deadly cancer in the United States. Currently, there are limited choices of targeted anticancer agents that are durably effective against colorectal cancer. Therefore, chemotherapeutic regimens containing the drugs Camptothecin (CPT), 5-FU and Oxaliplatin remain the mainstays for the treatment of advanced colorectal cancer. We recently found that the indole-derivative small compound Bromoethyl Indole (BEI) potently inhibits the proliferation of colon cancer cells and also suppresses NF-kB activation. In this study, we investigated if the combination of BEI with either CPT or TNFα would enhance cell death in vitro. Metastasis-derived parental or engineered NF-kB-reporter colon cancer cells were used to examine 1) the activation of NF-kB signaling by clinically used drugs, 2) the potential for BEI to inhibit drug-induced NF-kB activation, and 3) the potential for combination treatment to enhance cell death in vitro. Cells were treated with eit...

Research paper thumbnail of Prognostic and Predictive Biomarkers for Colorectal Cancer

Biomarkers in Cancer Screening and Early Detection

Research paper thumbnail of cIAP1 Localizes to the Nuclear Compartment and Modulates the Cell Cycle

Cancer Research

We explored the location and function of the human cIAP1 protein, a member of the inhibitor of ap... more We explored the location and function of the human cIAP1 protein, a member of the inhibitor of apoptosis protein (IAP) family. Unlike family member X-linked IAP (XIAP), which was predominantly cytoplasmic, the cIAP1 protein localized almost exclusively to nuclei in cells, as determined by immunofluorescence microscopy and subcellular fractionation methods. Interestingly, apoptotic stimuli induced nuclear export of cIAP1, which was blocked by a chemical caspase inhibitor. In dividing cells, cIAP1 was released into the cytosol early in mitosis, then reaccumulated in nuclei in late anaphase and in telophase, with the exception of a pool of cIAP1 that associated with the midbody. Survivin, another IAP family member, and cIAP1 were both localized on midbody microtubules at telophase, and also interacted with each other during mitosis. Cells stably overexpressing cIAP1 accumulated in G2-M phase and grew slower than control-transfected cells. These cIAP1-overexpressing cells also exhibited...

Research paper thumbnail of Molecular phylogeny of coronaviruses and host receptors among domestic and close-contact animals reveals subgenome-level conservation, crossover, and divergence

BMC Veterinary Research

Background Coronaviruses have the potential to cross species barriers. To learn the molecular int... more Background Coronaviruses have the potential to cross species barriers. To learn the molecular intersections among the most common coronaviruses of domestic and close-contact animals, we analyzed representative coronavirus genera infecting mouse, rat, rabbit, dog, cat, cattle, white-tailed deer, swine, ferret, mink, alpaca, Rhinolophus bat, dolphin, whale, chicken, duck and turkey hosts; reference or complete genome sequences were available for most of these coronavirus genera. Protein sequence alignments and phylogenetic trees were built for the spike (S), envelope (E), membrane (M) and nucleocapsid (N) proteins. The host receptors and enzymes aminopeptidase N (APN), angiotensin converting enzyme 2 (ACE2), sialic acid synthase (SAS), transmembrane serine protease 2 (TMPRSS2), dipeptidyl peptidase 4 (DPP4), cathepsin L (and its analogs) and furin were also compared. Results Overall, the S, E, M, and N proteins segregated according to their viral genera (α, β, or γ), but the S protein...

Research paper thumbnail of Loss of Neuroligin 4X Induces an Intrinsic Innate Immune Response in TNBC

BackgroundImmune checkpoint blockade therapies, which act on T cell inhibitory receptors, includi... more BackgroundImmune checkpoint blockade therapies, which act on T cell inhibitory receptors, including CTLA-4 and PD-1, induce durable responses across diverse cancers. However, most patients do not respond to these therapies, and initially responsive cancers may relapse. Identifying molecular mechanisms that influence therapeutic responses and resistance is critical to realize the full therapeutic potential of immune checkpoint inhibitors. The presence of immune infiltrates in the tumor microenvironment is associated with positive outcomes in breast cancer, specifically in triple-negative breast cancer (TNBC). The underlying mechanisms driving this response are unclear. We have previously identified Neuroligin 4X (NLGN4X) as a protein expressed in TNBC.MethodsBioinformatic analysis was used for pathway analysis of TCGA TNBC patient dataset. Immunohistochemistry was performed on breast cancer tissue microarray for NLGN4X protein expression. RNA-seq was performed on MDA-MB-231 breast ca...

Research paper thumbnail of Development of Drug Delivery System Using Bio based Calcium carbonate Nanoparticles

5-Fluorouracil (5-FU) is a well known anti-cancer drug which is commonly used for several cancer ... more 5-Fluorouracil (5-FU) is a well known anti-cancer drug which is commonly used for several cancer therapies. 5-FU is administered subcutaneously or intravenously to patients, and these results in low patient compliance. A better way to administer this 5-FU is in immediate need [1-2]. Calcium carbonate (CaCO3) nanoparticles are highly porous, biocompatible, biodegradable, and have pH-sensitive properties. These properties make CaCO3 nanoparticles one of the best candidates for a drug delivery system specially for 5-FU. In this research, the CaCO3 nanoparticles were derived from egg shells using sonochemical and mechanochemical methods. The glycerol and acetic acid were used as solvents in this process to avoid other toxic solvents. These nanoparticles were loaded with 5-FU drug by physical absorption. Oral administration of 5-FU can be beneficial to colon cancer patients as it could not only reduce the pain resulting in better compliance, but also mimic the physiological fate of 5-FU....

Research paper thumbnail of Synthesis and Characterization of PVP/CaCO3-Ag Blend Hydrogel by Gamma Irradiation: Study of Drug Delivery System and Antimicrobial Activity

The Minerals, Metals & Materials Series, 2019

Chronic wounds are skin injuries with failed healing. They have become a public health problem th... more Chronic wounds are skin injuries with failed healing. They have become a public health problem that affects more than 2% of the population and the presence of bacteria resistances difficult of treatment. Pseudomonas aeruginosa is opportunist pathogens and the treatment is difficult and requires a long period of treatment. Hydrogels are structure polymeric tridimensional and biocompatible. They have been used as a controlled delivery system for treatment of topic infection. Studies have reported calcium carbonate and silver ion can improve the mechanical properties and biocide activity of hydrogel. Here in this study, hydrogels loaded CaCO3-Ag were prepared using poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), agar, calcium carbonate, silver nitrate followed gamma irradiation with 25 kGy dose. The gel fraction, behavior swelling and biocide action against P. aeruginosa was investigated. The degree of swelling of the hydrogel loaded CaCO3-Ag was 12% higher than the unloaded and ...

Research paper thumbnail of Eggshell Based Nano-Engineered Hydroxyapatite and Poly(lactic) Acid Electrospun Fibers as Potential Tissue Scaffold

International Journal of Biomaterials, 2019

Nanocomposite electrospun fibers were fabricated from poly(lactic) acid (PLA) and needle-like hyd... more Nanocomposite electrospun fibers were fabricated from poly(lactic) acid (PLA) and needle-like hydroxyapatite nanoparticles made from eggshells. The X-ray diffraction spectrum and the scanning electron micrograph showed that the hydroxyapatite particles are highly crystalline and are needle-liked in shape with diameters between 10 and 20 nm and lengths ranging from 100 to 200 nm. The microstructural, thermal, and mechanical properties of the electrospun fibers were characterized using scanning electron microscope (SEM), thermogravimetric analysis (TGA), dynamic scanning calorimetry (DSC), and tensile testing techniques. The SEM study showed that both pristine and PLA/EnHA fibers surfaces exhibited numerous pores and rough edges suitable for cell attachment. The presence of the rod-liked EnHA particles was found to increase thermal and mechanical properties of PLA fibers relative to pristine PLA fibers. The confocal optical images showed that osteoblast cells were found to attach on d...

Research paper thumbnail of Camptothecin Induces PD-L1 and Immunomodulatory Cytokines in Colon Cancer Cells

Medicines, 2019

Background: Immunotherapy has changed the options for the treatment of various cancer types, but ... more Background: Immunotherapy has changed the options for the treatment of various cancer types, but not colon cancer. Current checkpoint blockade approaches are ineffective in a large proportion of colon cancer cases, necessitating studies to elucidate its mechanisms and to identify new targets and strategies against it. Methods: Here, we examined Programmed Death-Ligand 1(PD-L1), cytokine and receptor responses of colon cancer cells exposed to camptothecin (CPT), a clinically used topoisomerase inhibitor. Colon cancer cells were treated with CPT at concentrations of up to 10 µM, and the expressions of PD-L1 and immunoregulatory cytokine genes and receptors were analyzed. Results: PD-L1, a current immunotherapy target for various cancers, was shown to be upregulated in colon cancer cells independent of the cellular p53 status. In metastasis-derived SW620 cells, CPT most extensively upregulated cytokines with T-cell attraction or growth factor functions. Of those modulated genes, SPP1, ...

Research paper thumbnail of The Combination of Omega-3 Stearidonic Acid and Docetaxel Enhances Cell Death over Docetaxel Alone in Human Prostate Cancer Cells

Journal of Cancer, 2018

Background: Docetaxel (DOC), or Taxotere, is an anthracycline antibiotic used to treat multiple t... more Background: Docetaxel (DOC), or Taxotere, is an anthracycline antibiotic used to treat multiple types of cancer. It is a first-line chemotherapy treatment for patients with metastasized, hormone-resistant prostate cancer (PCa) or for patients with high-risk, localized PCa that could benefit from early chemotherapy treatment. Previously, we showed that stearidonic acid (SDA), an omega-3 fatty acid, enhances the cytotoxicity of doxorubicin (DOX) in human PCa cells. This observation suggests that PCa therapies using SDA and chemotherapeutic drugs in combination offer attractive possibilities for developing treatments that ameliorate toxic side effects of some commonly used chemotherapy drugs. Objectives: We used androgen-resistant PC3 and DU 145 cells derived from human prostate cancer to quantify the effects of combined SDA and DOC on proliferation/viability and on the production of pro-apoptotic caspases 9 and 3. We also compared the effects of SDA with those of BAY, a pharmacological inhibitor of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), in androgen-sensitive LNCaP cells. Finally, we qualitatively and quantitatively assessed the drug combination on androgen receptor (AR) and peroxisome proliferator-activated receptor gamma (PPARγ) expression in LNCaP and PC3 cells, respectively. Methods: The half maximal inhibitory concentration (IC50) and combination indices of SDA and DOC in PC3 and DU 145 cells were determined using the MTT cell viability assay. To quantify the effects of SDA and BAY on NF-ĸB activity, we used luciferase reporter assays in LNCaP cells that were stably transduced with lentiviral vectors carrying NF-ĸB response element sequence upstream of the luciferase gene sequence. AR and PPARγ expression were assessed by western blotting and immunocytochemistry. We considered caspase 9 and 3 cleavage to be apoptosis markers and determined the drug combination effect on the extent of that cleavage by western blot analysis. Results: The cytotoxic effects of DOC were synergistically enhanced by SDA when the two were added to DU145 and PC3 cell cultures. Combination index (CI) analyses based on the Chou-Talalay method and mass action law showed synergistic interaction with CI <1. SDA suppressed TNFα-induced NF-κB activity similarly to BAY. The SDA/DOC combination down regulated testosterone (T)-induced AR and troglitazone-induced PPARγ protein expression when compared to using the drugs singly. Similarly, the SDA/DOC combination induced caspase 9 and 3 production and cleavage suggesting apoptosis induction. Like our DOX studies, this work provides proof-of-concept for using SDA and DOC in combination to reduce the dose, and therefore the toxicity, of DOC and possibly increasing the survival benefit in DOC clinical translation studies.

Research paper thumbnail of Simultaneous Detection of Multiple Salmonella Serovars from Milk and Chicken Meat by Real-Time PCR Using Unique Genomic Target Regions

Journal of food protection, Jan 23, 2017

A novel genomic and plasmid target-based PCR platform was developed for the detection of Salmonel... more A novel genomic and plasmid target-based PCR platform was developed for the detection of Salmonella serovars Heidelberg, Dublin, Hadar, Kentucky, and Enteritidis. Unique genome loci were obtained through extensive genome mining of protein databases and comparative genomic analysis of these serovars. Assays targeting Salmonella serovars Hadar, Heidelberg, Kentucky, and Dublin had 100% specificity and sensitivity, whereas those for Salmonella Enteritidis had 97% specificity and 88% sensitivity. The limits of detection for Salmonella serovars Heidelberg, Kentucky, Hadar, Enteritidis, and Dublin were 12, 9, 40, 13, and 5,280 CFU, respectively. A sensitivity assay was also performed by using milk artificially inoculated with pooled Salmonella serovars, yielding a detection limit of 1 to10 CFU/25 mL of milk samples after enrichment. The minimum DNA detected using the multiplexed TaqMan assay was 75.8 fg (1.53 × 10 genomic equivalents [GE]) for Salmonella Heidelberg, 140.8 fg (2.8 × 10 GE)...

Research paper thumbnail of Effects of consumption of whole grape powder on basal NF-κB signaling and inflammatory cytokine secretion in a mouse model of inflammation

Journal of nutrition & intermediary metabolism, 2018

Dietary consumption of polyphenol-rich fruits, such as grapes, may reduce inflammation and potent... more Dietary consumption of polyphenol-rich fruits, such as grapes, may reduce inflammation and potentially prevent diseases linked to inflammation. Here, we used a genetically engineered murine model to measure Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) activity and pro-inflammatory cytokine secretion to test the hypothesis that oral consumption of whole grape formulation reduces inflammatory signaling in the body. NF-κB luciferase reporter mice were divided into two groups, one which was fed an experimental diet formulated with 4% (w/w) whole grape powder (WGP) or another which was fed a control diet formulated with 3.6% glucose/fructose (w/w) combination. Simulated inflammation was induced in the mice by intraperitoneal injection of lipopolysaccharide (LPS).imaging was used to determine the effect of each diet on NF-κB activity. We found that there were no significant differences in weight gain between the WGP and control diet groups. However, there was a s...

Research paper thumbnail of Bromoethylindole (BEI-9) redirects NF-κB signaling induced by camptothecin and TNFα to promote cell death in colon cancer cells

Apoptosis : an international journal on programmed cell death, 2017

Chemotherapeutic regimens containing camptothecin (CPT), 5-fluorouracil, and oxaliplatin are used... more Chemotherapeutic regimens containing camptothecin (CPT), 5-fluorouracil, and oxaliplatin are used to treat advanced colorectal cancer. We previously reported that an indole derivative, 3-(2-bromoethyl)indole (BEI-9), inhibited the proliferation of colon cancer cells and suppressed NF-κB activation. Here, we show that a combination of BEI-9 with either CPT or tumor necrosis factor alpha (TNFα) enhances cell death. Using colorectal cancer cells, we examined the activation of NF-κB by drugs, the potential of BEI-9 for inhibiting drug-induced NF-κB activation, and the enhancement of cell death by combination treatments. Cells were treated with the chemotherapeutic drugs alone or in combination with BEI-9. NF-κB activation, cell cycle profiles, DNA-damage response, markers of cell death signaling and targets of NF-κB were evaluated to determine the effects of single and co-treatments. The combination of BEI-9 with CPT or TNFα inhibited NF-κB activation and reduced the expression of NF-κB...

Research paper thumbnail of Nanoparticles for Detection, Diagnostics, and Targeting using Hyperspectral Imaging

Microscopy and Microanalysis, 2017

Novel and modified nanoparticles containing multiple inherent and specific functionalities make t... more Novel and modified nanoparticles containing multiple inherent and specific functionalities make them powerful tools in bioimaging, cancer targeting, cancer therapy, and microbial capture and detection. 1 For example, gold and iron oxide nanoparticles offer potential advantages in the bioimaging of cancer cells due to their respective strong absorption and scattering, and magnetic properties. 2 Several studies in the literature suggest the potency and efficiency of these nanoparticles in therapeutic applications. For example, per Alhalili Z. et al (2016), there was no observed significant decrease (P>0.05) in cell viability when TD47 cells are treated with gold nanoparticles (AuNPs) alone. 3 However, the same cells were significantly killed by the application of AuNPs chemically conjugated to Taxol, suggesting the potential of gold nanoparticles for efficient delivery of Taxol to breast cancer cells. Similarly, Ding R.L. (2017) reported the release of endostatin (ES) in a sustained manner in vitro that showed an excellent inhibitory effect on HUVECs proliferation and migration. 4 The study concluded that ES-NPs significantly improved the anticancer activity of ES by affecting angiogenesis. Despite similar developments in nanomaterial research, much remains to be done in terms of the characterization of the interaction between the cells and the drug loaded nanoparticles. In this study, we report the use of CytoViva Hyperspectral Imaging technology to identify cellular uptake of nanoparticles and to attempt to characterize (if any), the interaction between selected NPs and colon cancer cells.

Research paper thumbnail of Nanomaterial-based receptor conjugates for capture and rapid detection of Salmonella Enteritidis

Microscopy and Microanalysis, 2017

According to the Centers for Disease Control and Prevention (CDC), an estimated 1 in 6 Americans ... more According to the Centers for Disease Control and Prevention (CDC), an estimated 1 in 6 Americans become ill by consuming foods or beverages contaminated by disease causing pathogens each year [1]. Foodborne diseases have become a significant public health concern throughout the globe with an increase in incidence over the last two decades [2]. Salmonellosis is one of the most important bacterial diseases of food safety concern; and is caused primarily by Salmonella species such as Salmonella Enteritidis and Salmonella Typhimurium [3]. The World Health Organization (WHO) has shown statistics of tens of millions of new human cases and more than 100,000 deaths every year from individuals with symptoms that include fever, abdominal pain, diarrhea, nausea, and vomiting [3,4,5,6].

Research paper thumbnail of HM015k, a Novel Silybin Derivative, Multi-Targets Metastatic Ovarian Cancer Cells and Is Safe in Zebrafish Toxicity Studies

Frontiers in Pharmacology, 2017

This study was designed to determine the in vitro mechanisms by which the novel silybin derivativ... more This study was designed to determine the in vitro mechanisms by which the novel silybin derivative, (E)-3-(3-(benzyloxy) phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (HM015k or 15k), produces its anticancer efficacy in ovarian cancer cells. Compound 15k induced apoptosis in ovarian cancer cells in a time-dependent manner by significantly upregulating the expression of Bax and Bak and downregulating the expression of Bcl-2. Interestingly, 15k induced the cleavage of Bax p21 into its more efficacious cleaved form, Bax p18. In addition, caspase 3 and caspase 9 were cleaved to their active forms, inducing the cleavage of poly ADP ribose polymerase (PARP) and β-catenin. Furthermore, in OV2008 cells, 15k induced significant cleavage in nuclear β-catenin to primarily inactive fragments of lower molecular weight. Furthermore, 15k reversed the metastatic potential of OV2008 cells by inhibiting their migration and invasiveness. The mesenchymal phenotype in OV2008 was reversed by 15k, causing cells to be rounder with epithelial-like phenotypes. The 15k-induced reversal was further confirmed by significant upregulation of the E-cadherin expression, an epithelial marker, while N-cadherin, a mesenchymal marker, was downregulated in OV2008 cells. Compound 15k inhibited the expression of the oncogenic c-Myc protein, downregulated proteins DVL3 and DVL2 and significantly upregulated cyclin B1. Also, 15k significantly downregulated the expression levels of ABCG2 and ABCB1 transporters in resistant ABCG2 overexpressing H460/MX20 and resistant ABCB1 overexpressing MDCK/MDR1 cells, respectively. Finally, 15k was safe in zebrafish in vivo model at concentrations up to 10 µM and induced no major toxicities in cardiac, morphology and swimming position parameters. Overall, 15k is a multi-targeted inhibitor with efficacy against metastatic and resistant ovarian cancer. Future in vivo studies will be conducted to determine the efficacy of 15k in tumor-bearing animals.

Research paper thumbnail of Abstract 5910: Influence of 3D- cultured prostate cancer and stromal cells on drug response

Cancer Research, 2017

Background: Response to chemotherapeutic drugs presents a significant challenge to effective trea... more Background: Response to chemotherapeutic drugs presents a significant challenge to effective treatment of advanced prostate cancer. Exploration of therapeutic response has focused largely on the tumor cell. However, evidence suggests mechanisms that involve the tumor microenvironment mediate response to therapeutics. Therefore, it is imperative to mimic the in vivo tumor microenvironment, to bridge the gap between in vitro studies and the development of therapeutics. The concept of three-dimensional (3D) cell culture and co-culture of multiple cell types is critical to predict therapeutic efficacy and outcome. Thus, these studies sought to determine the distinct responses to anti-cancer drugs in 3D cell spheroids. Methods: In this study, we utilized metastatic prostate cancer cells (PC3) and fluorescently labeled prostate bone stromal cell line (HS27a) to generate tumor spheroids. Tumor spheroid viability was measured at 72 and 120 h using the CellTiter-Glo 3D assay after treatment ...

Research paper thumbnail of Polyphenolic Nutrients in Cancer Chemoprevention and Metastasis: Role of the Epithelial-to-Mesenchymal (EMT) Pathway

Nutrients, 2017

The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel targe... more The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel target in cancer prevention, metastasis, and resistance. The conversion of cells from an epithelial, adhesive state to a mesenchymal, motile state is one of the key events in the development of cancer metastasis. Polyphenols have been reported to be efficacious in the prevention of cancer and reversing cancer progression. Recently, the antimetastatic efficacy of polyphenols has been reported, thereby expanding the potential use of these compounds beyond chemoprevention. Polyphenols may affect EMT pathways, which are involved in cancer metastasis; for example, polyphenols increase the levels of epithelial markers, but downregulate the mesenchymal markers. Polyphenols also alter the level of expression and functionality of important proteins in other signaling pathways that control cellular mesenchymal characteristics. However, the specific proteins that are directly affected by polyphenols in these signaling pathways remain to be elucidated. The aim of this review is to analyze current evidence regarding the role of polyphenols in attenuating EMT-mediated cancer progression and metastasis. We also discuss the role of the most important polyphenol subclasses and members of the polyphenols in reversing metastasis and targeting EMT. Finally, limitations and future directions to improve our understanding in this field are discussed.

Research paper thumbnail of Nano-engineered eggshell-silver tailored co-polyester polymer blend film with antimicrobial properties

Journal of agricultural and food chemistry, Jan 16, 2017

In this study, the reinforcement effect of different proportions of eggshell/silver nanomaterial ... more In this study, the reinforcement effect of different proportions of eggshell/silver nanomaterial (ES-Ag) on structural and antimicrobial properties of 70/30 poly (butylene-co-adipate terephthalate)/polylactic acid (PBAT/PLA) immiscible blends were investigated. The ES-Ag was synthesized using a single step ball milling process, and characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). These results confirmed the existence of silver nanoparticles (Ag NPs) in the interstitial spaces of the eggshell particles. The thin films in this study were prepared using hot melt extrusion and 3D printing for mechanical and antimicrobial testing respectively. These films were also characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), XRD, tensile testing and antimicrobial analysis. It was found that the incorporation of ES-Ag (0.5-2.0 % content) compromi...

Research paper thumbnail of Molecular Biomarkers of Colorectal Cancer and Cancer Disparities: Current Status and Perspective

Current Colorectal Cancer Reports, 2016

This review provides updates on the efforts for the development of prognostic and predictive mark... more This review provides updates on the efforts for the development of prognostic and predictive markers in colorectal cancer based on the race/ethnicity of patients. Since the clinical consequences of genetic and molecular alterations differ with patient race and ethnicity, the usefulness of these molecular alterations as biomarkers needs to be evaluated in different racial/ ethnic groups. To accomplish personalized patient care, a combined analysis of multiple molecular alterations in DNA, RNA, microRNAs (miRNAs), metabolites, and proteins in a single test is

Research paper thumbnail of Abstract 3783: Co-treatment of metastasis-derived colon cancer cells with bromoethyl indole (BEI) enhances camptothecin or TNF alpha-induced cell death

Cancer Research, 2016

Colorectal cancer is still the third most deadly cancer in the United States. Currently, there ar... more Colorectal cancer is still the third most deadly cancer in the United States. Currently, there are limited choices of targeted anticancer agents that are durably effective against colorectal cancer. Therefore, chemotherapeutic regimens containing the drugs Camptothecin (CPT), 5-FU and Oxaliplatin remain the mainstays for the treatment of advanced colorectal cancer. We recently found that the indole-derivative small compound Bromoethyl Indole (BEI) potently inhibits the proliferation of colon cancer cells and also suppresses NF-kB activation. In this study, we investigated if the combination of BEI with either CPT or TNFα would enhance cell death in vitro. Metastasis-derived parental or engineered NF-kB-reporter colon cancer cells were used to examine 1) the activation of NF-kB signaling by clinically used drugs, 2) the potential for BEI to inhibit drug-induced NF-kB activation, and 3) the potential for combination treatment to enhance cell death in vitro. Cells were treated with eit...