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result(s) for
"Mehus, Scott"
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Status, Biology, and Conservation Priorities for North America's Eastern Golden Eagle (Aquila chrysaetos) Population
by
Miller, Tricia A.
,
Tremblay, Junior A.
,
Brinker, David F.
in
Biology
,
Bird migration
,
Coastal plains
2012
To minimize wildlife-turbine conflict, the USFWS established voluntary National Wind Energy Guidelines (2003) that recommend an Avian or Avian and Bat Protection Plan (ABPP) for compliance with the Migratory Bird Treaty Act. [...]given the historical distribution of Golden Eagles in eastern North America and the potential negative genetic consequences of translocation programs, we recommend that introductions or translocations of western Golden Eagles into states east of the Mississippi be discontinued.
Journal Article
Activation of PPARγ and inhibition of cell proliferation reduces key proteins associated with the basal subtype of bladder cancer in As3+-transformed UROtsa cells
2020
Environmental exposure to arsenite (As3+) has a strong association with the development of human urothelial cancer (UC) and is the 5th most common cancer in men and the 12th most common cancer in women. Muscle invasive urothelial cancer (MIUC) are grouped into basal or luminal molecular subtypes based on their gene expression profile. The basal subtype is more aggressive and can be associated with squamous differentiation, characterized by high expression of keratins (KRT1, 5, 6, 14, and 16) and epidermal growth factor receptor (EGFR) within the tumors. The luminal subtype is less aggressive and is predominately characterized by elevated gene expression of peroxisome proliferator-activated receptor- gamma (PPARγ) and forkhead box protein A1 (FOXA1). We have previously shown that As3+-transformed urothelial cells (As-T) exhibit a basal subtype of UC expressing genes associated with squamous differentiation. We hypothesized that the molecular subtype of the As-T cells could be altered by inducing the expression of PPARγ and/or inhibiting the proliferation of the cells. Non-transformed and As-T cells were treated with Troglitazone (TG, PPARG agonist, 10 μM), PD153035 (PD, an EGFR inhibitor, 1 μM) or a combination of TG and PD for 3 days. The results obtained demonstrate that treatment of the As-T cells with TG upregulated the expression of PPARγ and FOXA1 whereas treatment with PD decreased the expression of some of the basal keratins. However, a combined treatment of TG and PD resulted in a consistent decrease of several proteins associated with the basal subtype of bladder cancers (KRT1, KRT14, KRT16, P63, and TFAP2A). Our data suggests that activation of PPARγ while inhibiting cell proliferation facilitates the regulation of genes involved in maintaining the luminal subtype of UC. In vivo animal studies are needed to address the efficacy of using PPARγ agonists and/or proliferation inhibitors to reduce tumor grade/stage of MIUC.
Journal Article
Effect of Long-Term Cisplatin Exposure on the Proliferative Potential of Immortalized Renal Progenitor Cells
by
Sens, Donald A.
,
Singhal, Sandeep K.
,
Garrett, Scott H.
in
Acute Kidney Injury - chemically induced
,
Acute Kidney Injury - metabolism
,
Acute Kidney Injury - pathology
2024
Cisplatin (CisPt) is a widely used chemotherapeutic agent. However, its nephrotoxic effects pose significant risks, particularly for the development of acute kidney injury (AKI) and potential progression to chronic kidney disease (CKD). The present study investigates the impact of non-lethal exposure of CisPt to immortalized human renal epithelial precursor TERT cells (HRTPT cells) that co-express PROM1 and CD24, markers characteristic of renal progenitor cells. Over eight serial passages, HRTPT cells were exposed to 1.5 µM CisPt, leading to an initial growth arrest, followed by a gradual recovery of proliferative capacity. Despite maintaining intracellular platinum (Pt) levels, the cells exhibited normal morphology by passage eight (P8), with elevated expression of renal stress and damage markers. However, the ability to form domes was not restored. RNA-seq analysis revealed 516 differentially expressed genes between CisPt-exposed and control cells, with significant correlations to cell cycle and adaptive processes, as determined by the Reactome, DAVID, and Panther analysis programs. The progenitor cells treated with CisPt displayed no identity, or close identity, with cells of the normal human nephron. Additionally, several upregulated genes in P8 cells were linked to cancer cell lines, suggesting a complex interaction between CisPt exposure and cellular repair mechanisms. In conclusion, our study demonstrates that renal progenitor cells can recover from CisPt exposure and regain proliferative potential in the continued presence of both extracellular CisPt and intracellular Pt.
Journal Article
Chronic Arsenic Exposure Upregulates the Expression of Basal Transcriptional Factors and Increases Invasiveness of the Non-Muscle Invasive Papillary Bladder Cancer Line RT4
2022
The bladder is a target organ for inorganic arsenic, a carcinogen and common environmental contaminant found in soil and water. Urothelial carcinoma (UC) is the most common type of bladder cancer (BC) that develops into papillary or non-papillary tumors. Papillary tumors are mostly non-muscle invasive (NMIUC), easier treated, and have a better prognosis. Urothelial carcinoma can be molecularly sub-typed as luminal or basal, with papillary tumors generally falling into the luminal category and basal tumors exclusively forming muscle invasive urothelial carcinomas (MIUC). It is unclear why some UCs develop more aggressive basal phenotypes. We hypothesized that chronic arsenic exposure of a papillary luminal bladder cancer would lead to the development of basal characteristics and increase in invasiveness. We treated the human papillary bladder cancer cell line RT4 with 1 µM arsenite (As3+) for twenty passages. Throughout the study, key luminal and basal gene/protein markers in the exposed cells were evaluated and at passage twenty, the cells were injected into athymic mice to evaluate tumor histology and measure protein markers using immunohistochemistry. Our data indicates that chronic As3+- treatment altered cellular morphology and decreased several luminal markers in cell culture. The histology of the tumors generated from the As3+-exposed cells was similar to the parent (non-treated) however, they appeared to be more invasive in the liver and displayed elevated levels of some basal markers. Our study demonstrates that chronic As3+ exposure is able to convert a non-invasive papillary bladder cancer to an invasive form that acquires some basal characteristics.
Journal Article
The Effect of Retinoic Acid on Arsenite-Transformed Malignant UROtsa Bladder Cancer Cells: In Vitro Model of Basal Muscle-Invasive Bladder Cancer
2024
Bladder cancer (BC) is the eighth most common cause of cancer death in the United States of America. BC is classified into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Genetically, MIBCs are categorized into the more aggressive basal subtype or less aggressive luminal subtype. All-trans retinoic acid (tretinoin), the ligand for the RAR-RXR retinoic acid receptor, is clinically used as a differentiation therapy in hematological malignancies. This study aims to determine the effects of retinoic acid on arsenite-transformed malignant urothelial cells (UROtsa As), serving as a model for basal muscle-invasive bladder cancer. We treated three independent isolates of arsenite-transformed malignant human urothelial UROtsa cells (UROtsa As) with tretinoin for 48 h. Cell viability, proliferation, and apoptosis were analyzed using crystal violet staining and flow cytometry. mRNA and protein level analyses were performed using RT-qPCR and the Simple Western™ platform, respectively. Tretinoin was found to reduce cell proliferation and urosphere formation, as well as decrease the expression of basal markers (KRT1, KRT5, KRT6, EGFR) and increase the expression of luminal differentiation markers (GATA3, FOXA1). Mechanistically, the antiproliferative effect of tretinoin was attributed to the downregulation of c-myc. Our results suggest that targeting the retinoic acid pathway can diminish the aggressive behavior of basal muscle-invasive urothelial cancer and may enhance patient survival.
Journal Article
Proteasomes Are Critical for Maintenance of CD133+CD24+ Kidney Progenitor Cells
2023
Kidney progenitor cells, although rare and dispersed, play a key role in the repair of renal tubules after acute kidney damage. However, understanding these cells has been challenging due to the limited access to primary renal tissues and the absence of immortalized cells to model kidney progenitors. Previously, our laboratory utilized the renal proximal tubular epithelial cell line, RPTEC/TERT1, and the flow cytometry technique to sort and establish a kidney progenitor cell model called Human Renal Tubular Precursor TERT (HRTPT) which expresses CD133 and CD24 and exhibits the characteristics of kidney progenitors, such as self-renewal capacity and multi-potential differentiation. In addition, a separate cell line was established, named Human Renal Epithelial Cell 24 TERT (HREC24T), which lacks CD133 expression and shows no progenitor features. To further characterize HRTPT CD133+CD24+ progenitor cells, we performed proteomic profiling which showed high proteasomal expression in HRTPT kidney progenitor cells. RT-qPCR, Western blot, and flow cytometry analysis showed that HRTPT cells possess higher proteasomal expression and activity compared to HREC24T non-progenitor cells. Importantly, inhibition of the proteasomes with bortezomib reduced the expression of progenitor markers and obliterated the potential for self-renewal and differentiation of HRTPT progenitor cells. In conclusion, proteasomes are critical in preserving progenitor markers expression and self-renewal capacity in HRTPT kidney progenitors.
Journal Article
Pevonedistat Inhibits SOX2 Expression and Sphere Formation but Also Drives the Induction of Terminal Differentiation Markers and Apoptosis within Arsenite-Transformed Urothelial Cells
by
Zhou, Xu Dong
,
Sens, Donald A.
,
Garrett, Scott H.
in
Antigens, Differentiation
,
Apoptosis
,
Arsenic
2023
Urothelial cancer (UC) is a common malignancy and its development is associated with arsenic exposure. Around 25% of diagnosed UC cases are muscle invasive (MIUC) and are frequently associated with squamous differentiation. These patients commonly develop cisplatin (CIS) resistance and have poor prognosis. SOX2 expression is correlated to reduced overall and disease-free survival in UC. SOX2 drives malignant stemness and proliferation in UC cells and is associated with development of CIS resistance. Using quantitative proteomics, we identified that SOX2 was overexpressed in three arsenite (As3+)-transformed UROtsa cell lines. We hypothesized that inhibition of SOX2 would reduce stemness and increase sensitivity to CIS in the As3+-transformed cells. Pevonedistat (PVD) is a neddylation inhibitor and is a potent inhibitor of SOX2. We treated non-transformed parent and As3+-transformed cells with PVD, CIS, or in combination and monitored cell growth, sphere forming abilities, apoptosis, and gene/protein expression. PVD treatment alone caused morphological changes, reduced cell growth, attenuated sphere formation, induced apoptosis, and elevated the expression of terminal differentiation markers. However, the combined treatment of PVD with CIS significantly elevated the expression of terminal differentiation markers and eventually led to more cell death than either solo treatment. Aside from a reduced proliferation rate, these effects were not seen in the parent. Further research is needed to explore the potential use of PVD with CIS as a differentiation therapy or alternative treatment for MIUC tumors that may have become resistant to CIS.
Journal Article
Activation of PPARgamma and inhibition of cell proliferation reduces key proteins associated with the basal subtype of bladder cancer in As.sup.3+-transformed UROtsa cells
by
Zhou, Xu Dong
,
Mehus, Aaron A
,
Somji, Seema
in
Arsenic compounds
,
Bladder cancer
,
Cell proliferation
2020
Environmental exposure to arsenite (As.sup.3+) has a strong association with the development of human urothelial cancer (UC) and is the 5.sup.th most common cancer in men and the 12.sup.th most common cancer in women. Muscle invasive urothelial cancer (MIUC) are grouped into basal or luminal molecular subtypes based on their gene expression profile. The basal subtype is more aggressive and can be associated with squamous differentiation, characterized by high expression of keratins (KRT1, 5, 6, 14, and 16) and epidermal growth factor receptor (EGFR) within the tumors. The luminal subtype is less aggressive and is predominately characterized by elevated gene expression of peroxisome proliferator-activated receptor- gamma (PPAR[gamma]) and forkhead box protein A1 (FOXA1). We have previously shown that As.sup.3+ -transformed urothelial cells (As-T) exhibit a basal subtype of UC expressing genes associated with squamous differentiation. We hypothesized that the molecular subtype of the As-T cells could be altered by inducing the expression of PPAR[gamma] and/or inhibiting the proliferation of the cells. Non-transformed and As-T cells were treated with Troglitazone (TG, PPARG agonist, 10 [mu]M), PD153035 (PD, an EGFR inhibitor, 1 [mu]M) or a combination of TG and PD for 3 days. The results obtained demonstrate that treatment of the As-T cells with TG upregulated the expression of PPAR[gamma] and FOXA1 whereas treatment with PD decreased the expression of some of the basal keratins. However, a combined treatment of TG and PD resulted in a consistent decrease of several proteins associated with the basal subtype of bladder cancers (KRT1, KRT14, KRT16, P63, and TFAP2A). Our data suggests that activation of PPAR[gamma] while inhibiting cell proliferation facilitates the regulation of genes involved in maintaining the luminal subtype of UC. In vivo animal studies are needed to address the efficacy of using PPAR[gamma] agonists and/or proliferation inhibitors to reduce tumor grade/stage of MIUC.
Journal Article
Activation of PPARgamma and inhibition of cell proliferation reduces key proteins associated with the basal subtype of bladder cancer in As.sup.3+-transformed UROtsa cells
by
Zhou, Xu Dong
,
Sens, Donald A.
,
Garrett, Scott H.
in
Arsenic compounds
,
Bladder cancer
,
Cell proliferation
2020
Journal Article
Activation of PPARgamma and inhibition of cell proliferation reduces key proteins associated with the basal subtype of bladder cancer in As.sup.3+-transformed UROtsa cells
by
Zhou, Xu Dong
,
Sens, Donald A.
,
Garrett, Scott H.
in
Arsenic compounds
,
Bladder cancer
,
Cell proliferation
2020
Journal Article