Current Search:   Harriet L. Wilkes Honors College (x) » Cellular signal transduction (x)

View All Items

  • CSV Spreadsheet
(1 - 9 of 9)
Characterization of the motor protein, KIF9, in mammalian cell mitotic progression
Title
Characterization of the motor protein, KIF9, in mammalian cell mitotic progression.
Creator
Hoke, Jordan, Harriet L. Wilkes Honors College
Abstract/Description
The kinesin family of microtubule motors is divided into subfamilies based on structure and function. KIF9, founder of the Kinesin-9 family, has been found to interact with the GTPase Gem. Subsequent studies have shown that KIF9 is vital for flagellar movement and podosome regulation. Previous work has proposed KIF9 is required for microtubule organization as well as proper mitotic entry, progression and completion. In this study, I examined the function of KIF0 in mitotic progression using...
Show moreThe kinesin family of microtubule motors is divided into subfamilies based on structure and function. KIF9, founder of the Kinesin-9 family, has been found to interact with the GTPase Gem. Subsequent studies have shown that KIF9 is vital for flagellar movement and podosome regulation. Previous work has proposed KIF9 is required for microtubule organization as well as proper mitotic entry, progression and completion. In this study, I examined the function of KIF0 in mitotic progression using shRNA-mediated knockdown, and overexpression. In knockdown cells, I saw a significant delay in mitotic progression as well as an increase in multipolarity and multinuclearity, suggesting a failure of cytokinesis. Overexpression of KIF9 produced similar effects on mitotic progression, as well as a marked increase in chromosome distance during anaphase. Taken with previous results, my research indicated that KIF9 is required for normal mitotic progression and completion, possible via regulation of the contractile ring.
Show less
Date Issued
2012
PURL
http://purl.flvc.org/FAU/3359298
Subject Headings
Cells, Motility, Protoplasmic streaming, Cell organelles, Cellular signal transduction, Cytoskeletal proteins
Format
Document (PDF)
Devising a noncancerous model system to study multipolar spindle formation
Title
Devising a noncancerous model system to study multipolar spindle formation.
Creator
Nagarsheth, Nisha., Harriet L. Wilkes Honors College
Abstract/Description
Aneuploid tumor cells have characteristically unstable genomes which can be caused by mitotic defects such as multipolar spindles. Multipolarity relies upon the presence of extra centrosomes to form. However, some cells, both cancerous and noncancerous are able to avoid the formation of multipolar spindles through centrosomal clustering. Previous research has shown that there are a large number of genes whose activity contributes to the clustering activity, making analysis of individual...
Show moreAneuploid tumor cells have characteristically unstable genomes which can be caused by mitotic defects such as multipolar spindles. Multipolarity relies upon the presence of extra centrosomes to form. However, some cells, both cancerous and noncancerous are able to avoid the formation of multipolar spindles through centrosomal clustering. Previous research has shown that there are a large number of genes whose activity contributes to the clustering activity, making analysis of individual components of the process difficult. In order to better understand centrosomal clustering in cancer cells, we induced supernumerary centrosomes in a genomically normal cell line, RPE, to observe how the normal cells cope with extra centrosomes. Using colcemid to induce extra centrosomes in the RPE cell line, we observed an intact clustering mechanism in fixed cells. Further manipulation of the cells has allowed us to induce multipolarity in this cell line using various disrupters of cell-cycle checkpoint and dynein function.
Show less
Date Issued
2010
PURL
http://purl.flvc.org/FAU/3335107
Subject Headings
Centrosomes, Research, Cancer, Genetic aspects, Cellular signal transduction, Cell division
Format
Document (PDF)
Manipulation of normal cells to produce a cancer-like mitotic phenotype
Title
Manipulation of normal cells to produce a cancer-like mitotic phenotype.
Creator
Luffman, Christina., Harriet L. Wilkes Honors College
Abstract/Description
Most tumors contain multiple karyotypes due to genomic instability gained through chromosomal segregational defects. The variability of genomic changes within a population makes it difficult to study specific processes without the existence of confounding mutations. My project is to create a model system for observation of mitotic defects, specifically multipolar spindles, in a normal cell line, where the genome is intact. Induction of centrosome amplification is required for formation of...
Show moreMost tumors contain multiple karyotypes due to genomic instability gained through chromosomal segregational defects. The variability of genomic changes within a population makes it difficult to study specific processes without the existence of confounding mutations. My project is to create a model system for observation of mitotic defects, specifically multipolar spindles, in a normal cell line, where the genome is intact. Induction of centrosome amplification is required for formation of multipolar spindles. Treatments with colcemid showed a 10% increase in abnormal centrosome numbers over control. However, treatment with hydroxyurea and transfection of hMPSl showed little increase. Extra centrosomes are insufficient to drive multipolarity, therefore, I am using siRNA-mediated knockdown of Nek2 or HSET to decluster the extra centrosomes. Successful declustering will preferably show an increase in multipolar frequency, allowing us to study the formation and resolution of these structres to better understand how they contribute to aneuploidy and tumor progression.
Show less
Date Issued
2009
PURL
http://purl.flvc.org/FAU/3325079
Subject Headings
Cell division, Karyokinesis, Cancer, Genetic aspects, Genomics, Cellular signal transduction, Centrosomes
Format
Document (PDF)
Deamplification of supernumerary centrosomes by centrosomal clustering
Title
Deamplification of supernumerary centrosomes by centrosomal clustering.
Creator
Thomas, Ezekiel., Harriet L. Wilkes Honors College
Abstract/Description
Supernumerary centrosomes can arise in a cell through a variety of methods. The presence of supernumerary centrosomes has been observed in nearly all types of cancer and promotes chromosomal instability, with rates of incident increasing as the cancer progresses. An oral squamous cell carcinoma line was treated with hydroxyurea to induce supernumerary centrosomes in the cells. NuMA was then knocked down using shRNA to promote centrosomal clustering and bipolar mitotic division in cells with...
Show moreSupernumerary centrosomes can arise in a cell through a variety of methods. The presence of supernumerary centrosomes has been observed in nearly all types of cancer and promotes chromosomal instability, with rates of incident increasing as the cancer progresses. An oral squamous cell carcinoma line was treated with hydroxyurea to induce supernumerary centrosomes in the cells. NuMA was then knocked down using shRNA to promote centrosomal clustering and bipolar mitotic division in cells with supernumerary centrosomes. Immunofluorescence with an antibody against SAS 6 accuately stained the centrioles for observation. The cells exhibiting supernumerary centrosomes undergoing bipolar mitotic division were studied to look for a possible pattern in centrosomal clustering where the majority of centrosomes are at one pole with a single centrosome at the other pole. Initial results suggest the presence of such a mechanism, which would describe a previously unknown mechanism for cells to deamplify supernumerary centrosomes by centrosomal clustering.
Show less
Date Issued
2012
PURL
http://purl.flvc.org/FAU/3359328
Subject Headings
Centrosomes, Cell division, Cellular signal transduction, Cancer, Genetic aspects
Format
Document (PDF)
Determination of the acid dissociation constant of cytochrome B5 reductase
Title
Determination of the acid dissociation constant of cytochrome B5 reductase.
Creator
Chong, Samantha., Harriet L. Wilkes Honors College
Abstract/Description
Most living organisms transduce electron transport chains in order to obtain energy. Flavin adenine dinucleotide (FAD) is a common electron transfer cofactor found in electron transport proteins referred to as flavoproteins. In this study, the different ionization and oxidation states of this cofactor found in cytochrome b5 reductase were identified spectroscopically and quantified as a function of solution potential and pH. The large data sets obtained from these experiments were analyzed...
Show moreMost living organisms transduce electron transport chains in order to obtain energy. Flavin adenine dinucleotide (FAD) is a common electron transfer cofactor found in electron transport proteins referred to as flavoproteins. In this study, the different ionization and oxidation states of this cofactor found in cytochrome b5 reductase were identified spectroscopically and quantified as a function of solution potential and pH. The large data sets obtained from these experiments were analyzed and the acid dissociation constant for reduced cytochrome b5 reductase was determined.
Show less
Date Issued
2008
PURL
http://purl.flvc.org/FAU/77662
Subject Headings
Cell metabolism, Cellular signal transduction, Chemistry, Statistical methods, Electron spectroscopy
Format
Document (PDF)
Correlation between specific carcinogenic chemicals and specific mitotic defects and the restorative role of antioxidants
Title
Correlation between specific carcinogenic chemicals and specific mitotic defects and the restorative role of antioxidants.
Creator
Yates, Travis., Harriet L. Wilkes Honors College
Abstract/Description
The progression of cancerous cells towards a more aggressive tumor can be linked to external elements called carcinogens. The goal of this project is to examine the correlation between exposure to specific carcinogens and an increase of mitotic defects. These defects can manifest as lagging chromosomes, multipolar spindles, and anaphase bridges. Some of these instabilities are associated with the formation of reactive oxygen species (ROS), which are known to damage DNA. The potential for...
Show moreThe progression of cancerous cells towards a more aggressive tumor can be linked to external elements called carcinogens. The goal of this project is to examine the correlation between exposure to specific carcinogens and an increase of mitotic defects. These defects can manifest as lagging chromosomes, multipolar spindles, and anaphase bridges. Some of these instabilities are associated with the formation of reactive oxygen species (ROS), which are known to damage DNA. The potential for damage to the genome can be averted via antioxidants. Using the oral cancer cell line UPCI:SCC103, we established a baseline for the mitotic defects in the absence and presence of various ROS-inducing carcinogens using DAPI-stained fixed cells examined by immunofluorescent microscopy, The cells were treated with varying concentrations of the antioxidants, Vitamin C, (Sb(B-Carotene, and Vitamin E. The reactive oxygen scavengers significantly reduced the number of mitotic defects. A possible link between the carcinogens and lagging chromosomes was established.
Show less
Date Issued
2009
PURL
http://purl.flvc.org/FAU/210007
Subject Headings
Cellular signal transduction, Genetic regulation, Antioxidants, Therapeutic use, Apoptosis, Molecular aspects, Cancer, Chemoprevention
Format
Document (PDF)
Knockdown of KIF9 leads to defects in mitotic entry and progression in mammalian cells
Title
Knockdown of KIF9 leads to defects in mitotic entry and progression in mammalian cells.
Creator
Alsina, Laura., Harriet L. Wilkes Honors College
Abstract/Description
Kinesin motors bind to microtubules and function in mitosis and intracellular transport depending on the position of the motor domain within the primary sequence (Hirokawa and Noda 2008). KIF9 has recently been shown to be involved in MTOC positioning and mitotic entry in Dictyostelium (Tikhonenko et al. 2009). To determine if a similar role for KIF9 exists in mammalian cells, we are using siRNA-mediated knockdown of KIF9 in COS-7 cells. Analysis of unsynchronized and cell-cycle synchronized...
Show moreKinesin motors bind to microtubules and function in mitosis and intracellular transport depending on the position of the motor domain within the primary sequence (Hirokawa and Noda 2008). KIF9 has recently been shown to be involved in MTOC positioning and mitotic entry in Dictyostelium (Tikhonenko et al. 2009). To determine if a similar role for KIF9 exists in mammalian cells, we are using siRNA-mediated knockdown of KIF9 in COS-7 cells. Analysis of unsynchronized and cell-cycle synchronized cells treated with siRNA to KIF9 reveal that the transition from G2 to M phase is delayed and that mitotic progression is also affected. Additionally, our data indicates that spindle pole function during anaphase may be abnormal in cells treated with siRNA, suggesting a role for KIF9 during that stage.
Show less
Date Issued
2010
PURL
http://purl.flvc.org/FAU/3334255
Subject Headings
Cells, Motility, Protoplasmic streaming, Cell organelles, Formation, Cellular signal transduction
Format
Document (PDF)
Cells and cocktails
Title
Cells and cocktails: antioxidants rescue carcinogen induced mitotic defects in both chromosomally stable and unstable cells.
Creator
Griffin, Isabel Sloan., Harriet L. Wilkes Honors College
Abstract/Description
Tumor cells are characterized by an increase in genomic instability, brought about by both chromosomal rearrangement and chromosomal instability. Both of these broad changes can be induced by exposure to carcinogens. During mitosis, cells can exhibit early and late lagging chromosomes, multipolar spindles or anaphase bridges, all of which contribute to genomic rearrantement. We have studied the link between exposure to carcinogen and prevalence of mitotic defect in both chromosomally stable...
Show moreTumor cells are characterized by an increase in genomic instability, brought about by both chromosomal rearrangement and chromosomal instability. Both of these broad changes can be induced by exposure to carcinogens. During mitosis, cells can exhibit early and late lagging chromosomes, multipolar spindles or anaphase bridges, all of which contribute to genomic rearrantement. We have studied the link between exposure to carcinogen and prevalence of mitotic defect in both chromosomally stable and unstable cell lines as well as ecamined the restorative effects of antioxidants in preventing mitotic defects. We have exposed MES-SA uterine cancer cells to vinyl chloride followed by exposure to an antioxidant : ascorbic acid, B-carotene, or lycopene. Treated cells were then scored for the prevalence of mitotic defects within the population and compared to controls. We have also investigated whether pre-treatment with the antioxidants will weaken the effects of carcinogen exposure in these cell lines.
Show less
Date Issued
2012
PURL
http://purl.flvc.org/FAU/3359304
Subject Headings
Cellular signal transduction, Cell differentiation, Medical genetics, Cancer, Genetic aspects, Antioxidants, Therapeutic use, Cancer, Chemoprevention, Apoptosis, Molecular aspects, Genetic regulation
Format
Document (PDF)
Adopting the orphan: determining the role of the motor protein KIF9 during the cell cycle
Title
Adopting the orphan: determining the role of the motor protein KIF9 during the cell cycle.
Creator
Rivera Rios, Miguel E., Harriet L. Wilkes Honors College
Abstract/Description
The kinesin superfamily of microtubule motor proteins is subdivided into families based upon structure and function. KIF9 is the founding member of the Kinesin-9 family, which is a largely uncharacterized group of kinesins. It was originally identified by sequence homology to other kinesins. Subsequent studies have shown that KIF9 interacts with proteins involved in cell shape remodeling, cell migration and proper centrosomal positioning. We have examined KIF9 function in mammalian cells...
Show moreThe kinesin superfamily of microtubule motor proteins is subdivided into families based upon structure and function. KIF9 is the founding member of the Kinesin-9 family, which is a largely uncharacterized group of kinesins. It was originally identified by sequence homology to other kinesins. Subsequent studies have shown that KIF9 interacts with proteins involved in cell shape remodeling, cell migration and proper centrosomal positioning. We have examined KIF9 function in mammalian cells using shRNA-mediated knockdown and GFP-plasmid overexpression. By knocking dow KIF9 expression in these cells, we have seen several effects on normal cell cycle progression. Using various cell cycle markers, we have observed a decrease in the number of cells in late S phase. In addition, there is a marked increase in the number of cells in early mitosis in unexpected time intervals. We propose that KIF9 is required for proper cell progression, via a potentially novel checkpoint mechanism.
Show less
Date Issued
2012
PURL
http://purl.flvc.org/FAU/3359321, http://purl.flvc.org/fau/fd/FADT3359321
Subject Headings
Cell organelles, Formation, Cellular signal transduction, Protoplasmic streaming, Cells, Motility, Cell division, Research
Format
Document (PDF)