Alexandra LaPat Polasko

All Publications

• Establishing and characterizing the molecular profiles, cellular features, and clinical utility of a patient-derived xenograft model using benign prostatic tissues. Laboratory investigation; a journal of technical methods and pathology Polasko, A. L., Zhang, D., Ramraj, A., Chiu, C. L., Garcia-Marques, F. J., Bermudez, A., Kapp, K., Peterson, E., Qiu, Z., Pollack, A. S., Zhao, H., Pollack, J. R., Pitteri, S. J., Brooks, J. D. 2024: 102129

  Abstract

  Benign Prostatic Hyperplasia (BPH) is a common condition marked by the enlargement of the prostate gland, which often leads to significant urinary symptoms and a decreased quality of life. The development of clinically relevant animal models is crucial for understanding the pathophysiology of BPH and improving treatment options. This study aims to establish a patient-derived xenograft (PDX) model using benign prostatic tissues to explore the molecular and cellular mechanisms of BPH. PDXs were generated by implanting fresh BPH (transition zone) and paired normal (peripheral zone) prostate tissue from eight patients under the renal capsule of immunodeficient male mice. Tissue weight, architecture, cellular proliferation, apoptosis, prostate-specific marker expression, and molecular profiles of PDXs were assessed after 1 week, 1 month, 2 months, or 3 months of implantation by immunohistochemistry, ELISA, transcriptomics, and proteomics. Responses to finasteride, a standard-of-care therapy, were evaluated. PDXs maintained the histological and molecular characteristics of the parental human tissues. BPH, but not normal PDXs, demonstrated significant increases in weight and cellular proliferation, particularly at 1 month. Molecular profiling revealed specific gene and protein expression patterns correlating with BPH pathophysiology. Specifically, an increased immune and stress response was observed at 1 week, followed by increased expression of proliferation markers and BPH-specific stromal signaling molecules, such as BMP5 and CXCL13, at 1 month. Graft stabilization to pre-implant characteristics was apparent between 2 and 3 months. Treatment with finasteride reduced proliferation, increased apoptosis, and induced morphological changes consistent with therapeutic responses observed in human BPH. Our PDX model recapitulates the morphological, histological, and molecular features of human BPH, offering a significant advancement in modeling the complex interactions of cell types in BPH microenvironments. These PDXs respond to therapeutic intervention as expected, providing a valuable tool for preclinical testing of new therapeutics which will improve the well-being for BPH patients.

  View details for DOI 10.1016/j.labinv.2024.102129

  View details for PubMedID 39222914

• Enhanced in situ bioremediation of chlorinated ethenes: from in situ microcosms to full-scale application BIOREMEDIATION JOURNAL Polasko, A. L., Ponticello, W., Mahendra, S., LaPat-Polasko, L. 2024

  View details for DOI 10.1080/10889868.2024.2361646

  View details for Web of Science ID 001238934500001

• Evaluation of historical data on persistent organic pollutants and heavy metals in Lake Baikal: Implications for accumulation in marine environments. Environmental research Polasko, A. L., Koutnik, V. S., Tsai, K., Alkidim, S., Borthakur, A., Mohanty, S., Mahendra, S. 2024; 252 (Pt 3): 119035

  Abstract

  Lake Baikal, the largest freshwater lake by volume, provides drinking water and aquatic food supplies to over 2.5 million people. However, the lake has been contaminated with recalcitrant pollutants released from surrounding industrial complexes, agriculture, and natural lands, thereby increasing the risk of their bioaccumulation in fish and seals. Yet, a collective analysis of historical concentration data and their bioaccumulation potential as well as what factors drive their accumulation in fish or seals remains largely unknown. We analyzed concentration data from 42 studies collected between 1985 and 2019 in water, sediment, fish, and seals of Lake Baikal. Heavy metals had the highest concentrations in water and biota followed closely by polycyclic aromatic hydrocarbons (PAHs) and organochlorines. Among organochlorines, polychlorinated biphenyls (PCBs) showed the highest levels in water, surpassing hexachlorocyclohexane (HCH) concentrations, particularly after normalizing to solubility. While naphthalene and phenanthrene exhibited the highest average concentrations among polycyclic aromatic hydrocarbons (PAHs), their relative concentrations significantly decreased upon solubility normalization. The analysis confirmed that bioconcentration and biomagnification of organochlorine pesticides, PCBs, PAHs, and heavy metals depend primarily on source strength to drive their concentration in water and secondarily on their chemical characteristics as evidenced by the higher concentrations of low-solubility PCBs and high molecular weight PAHs in water and sediment. The differential biomagnification patterns of Cu, Hg, and Zn compared to Pb are attributed to their distinct sources and bioavailability, with Cu, Hg, and Zn showing more pronounced biomagnification due to prolonged industrial release, in contrast to the declining Pb levels. Dibenzo-p-dioxins were detected in sediment and seals, but not in water or fish compartments. These data highlight the importance of addressing even low concentrations of organic and inorganic pollutants and the need for more consistent and frequent monitoring to ensure the future usability of this and other similar essential natural resources.

  View details for DOI 10.1016/j.envres.2024.119035

  View details for PubMedID 38685302

• AZGP1 deficiency promotes angiogenesis in prostate cancer. Journal of translational medicine Wen, R. M., Qiu, Z., Marti, G. E., Peterson, E. E., Marques, F. J., Bermudez, A., Wei, Y., Nolley, R., Lam, N., Polasko, A. L., Chiu, C. L., Zhang, D., Cho, S., Karageorgos, G. M., McDonough, E., Chadwick, C., Ginty, F., Jung, K. J., Machiraju, R., Mallick, P., Crowley, L., Pollack, J. R., Zhao, H., Pitteri, S. J., Brooks, J. D. 2024; 22 (1): 383

  Abstract

  Loss of AZGP1 expression is a biomarker associated with progression to castration resistance, development of metastasis, and poor disease-specific survival in prostate cancer. However, high expression of AZGP1 cells in prostate cancer has been reported to increase proliferation and invasion. The exact role of AZGP1 in prostate cancer progression remains elusive.AZGP1 knockout and overexpressing prostate cancer cells were generated using a lentiviral system. The effects of AZGP1 under- or over-expression in prostate cancer cells were evaluated by in vitro cell proliferation, migration, and invasion assays. Heterozygous AZGP1± mice were obtained from European Mouse Mutant Archive (EMMA), and prostate tissues from homozygous knockout male mice were collected at 2, 6 and 10 months for histological analysis. In vivo xenografts generated from AZGP1 under- or over-expressing prostate cancer cells were used to determine the role of AZGP1 in prostate cancer tumor growth, and subsequent proteomics analysis was conducted to elucidate the mechanisms of AZGP1 action in prostate cancer progression. AZGP1 expression and microvessel density were measured in human prostate cancer samples on a tissue microarray of 215 independent patient samples.Neither the knockout nor overexpression of AZGP1 exhibited significant effects on prostate cancer cell proliferation, clonal growth, migration, or invasion in vitro. The prostates of AZGP1-/- mice initially appeared to have grossly normal morphology; however, we observed fibrosis in the periglandular stroma and higher blood vessel density in the mouse prostate by 6 months. In PC3 and DU145 mouse xenografts, over-expression of AZGP1 did not affect tumor growth. Instead, these tumors displayed decreased microvessel density compared to xenografts derived from PC3 and DU145 control cells, suggesting that AZGP1 functions to inhibit angiogenesis in prostate cancer. Proteomics profiling further indicated that, compared to control xenografts, AZGP1 overexpressing PC3 xenografts are enriched with angiogenesis pathway proteins, including YWHAZ, EPHA2, SERPINE1, and PDCD6, MMP9, GPX1, HSPB1, COL18A1, RNH1, and ANXA1. In vitro functional studies show that AZGP1 inhibits human umbilical vein endothelial cell proliferation, migration, tubular formation and branching. Additionally, tumor microarray analysis shows that AZGP1 expression is negatively correlated with blood vessel density in human prostate cancer tissues.AZGP1 is a negative regulator of angiogenesis, such that loss of AZGP1 promotes angiogenesis in prostate cancer. AZGP1 likely exerts heterotypical effects on cells in the tumor microenvironment, such as stromal and endothelial cells. This study sheds light on the anti-angiogenic characteristics of AZGP1 in the prostate and provides a rationale to target AZGP1 to inhibit prostate cancer progression.

  View details for DOI 10.1186/s12967-024-05183-x

  View details for PubMedID 38659028

  View details for PubMedCentralID 321763

• Original Proteomics analysis of urine and catheter-associated biofilms in spinal cord injury patients AMERICAN JOURNAL OF CLINICAL AND EXPERIMENTAL UROLOGY Garcia-Marques, F. J., Zakrasek, E., Bermudez, A., Polasko, A. L., Liu, S., Stoyanova, T., Brooks, J., Lavelle, J., Pitteri, S. J. 2023; 11 (3): 206-219

  View details for Web of Science ID 001021892100002

• A Readily Scalable, Clinically Demonstrated, Antibiofouling Zwitterionic Surface Treatment for Implantable Medical Devices ADVANCED MATERIALS McVerry, B., Polasko, A., Rao, E., Haghniaz, R., Chen, D., He, N., Ramos, P., Hayashi, J., Curson, P., Wu, C., Bandaru, P., Anderson, M., Bui, B., Sayegh, A., Mahendra, S., Di Carlo, D., Kreydin, E., Khademhosseini, A., Sheikhi, A., Kaner, R. B. 2022; 34 (20): e2200254

  Abstract

  Unlike growth on tissue, microbes can grow freely on implantable devices with minimal immune system intervention and often form resilient biofilms that continuously pump out pathogenic cells. The efficacy of antibiotics used to treat infection is declining due to increased rates of pathogenic resistance. A simple, one-step zwitterionic surface modification is developed to significantly reduce protein and microbial adhesion to synthetic materials and demonstrate the successful modification of several clinically relevant materials, including recalcitrant materials such as elastomeric polydimethylsiloxane. The treated surfaces exhibit robust adhesion resistance against proteins and microorganisms in both static and flow conditions. Furthermore, the surface treatment prevents the adhesion of mammalian fibroblast cells while displaying no cytotoxicity. To demonstrate the clinical efficacy of the novel technology in the real-world, a surface-treated, commercial silicone foley catheter is developed that is cleared for use by the U.S. Food and Drug Administration (K192034). 16 long-term catheterized patients received surface-treated catheters and completed a Patient Global Impression of Improvement (PGI-I) questionnaire. 10 out of 16 patients described their urinary tract condition post implantation as "much better" or "very much better" and 72% (n = 13) of patients desire to continue using the surface-treated catheter over conventional latex or silicone catheters.

  View details for DOI 10.1002/adma.202200254

  View details for Web of Science ID 000781050900001

  View details for PubMedID 35315553

  View details for PubMedCentralID PMC9153982

• Profiling microbial community structures and functions in bioremediation strategies for treating 1,4-dioxane-contaminated groundwater JOURNAL OF HAZARDOUS MATERIALS Miao, Y., Heintz, M. B., Bell, C. H., Johnson, N. W., Polasko, A., Favero, D., Mahendra, S. 2021; 408: 124457

  Abstract

  Microbial community compositions and functional profiles were analyzed in microcosms established using aquifer materials from a former automobile factory site, where 1,4-dioxane was identified as the primary contaminant of concern. Propane or oxygen biostimulation resulted in limited 1,4-dioxane degradation, which was markedly enhanced with the addition of nutrients, resulting in abundant Mycobacterium and Methyloversatilis taxa and high expressions of propane monooxygenase gene, prmA. In bioaugmented treatments, Pseudonocardia dioxanivorans CB1190 or Rhodococcus ruber ENV425 strains dominated immediately after augmentation and degraded 1,4-dioxane rapidly which was consistent with increased representation of xenobiotic and lipid metabolism-related functions. Although the bioaugmented microbes decreased due to insufficient growth substrates and microbial competition, they did continue to degrade 1,4-dioxane, presumably by indigenous propanotrophic and heterotrophic bacteria, inducing similar community structures across bioaugmentation conditions. In various treatments, functional redundancy acted as buffer capacity to ensure a stable microbiome, drove the restoration of the structure and microbial functions to original levels, and induced the decoupling between basic metabolic functions and taxonomy. The results of this study provided valuable information for design and decision-making for ex-situ bioreactors and in-situ bioremediation applications. A metagenomics-based understanding of the treatment process will enable efficient and accurate adjustments when encountering unexpected issues in bioremediation.

  View details for DOI 10.1016/j.jhazmat.2020.124457

  View details for Web of Science ID 000620383200005

  View details for PubMedID 33189472

• Vinyl chloride and 1,4-dioxane metabolism by Pseudonocardia dioxanivorans CB1190 Journal of Hazardous Materials Letters Polasko, A. L., Miao, Y., Kwok, I., Park, J. O., Mahendra, S. 2021; 2 (100039)

  View details for DOI 10.1016/j.hazl.2021.100039

• A multipronged approach for accurate in vitro quantification of catheter-associated biofilms Journal of Hazardous Materials Letters Polasko, A. L., Ramos, P., Kaner, R. B., Mahendra, S. 2021; 2 (10032)

  View details for DOI 10.1016/j.hazl.2021.100032

• A Mixed Microbial Community for the Biodegradation of Chlorinated Ethenes and 1,4-Dioxane ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS Polasko, A., Zulli, A., Gedalanga, P. B., Pornwongthong, P., Mahendra, S. 2019; 6 (1): 49-54

  View details for DOI 10.1021/acs.estlett.8b00591

  View details for Web of Science ID 000455557800009

• Co-contaminant effects on 1,4-dioxane biodegradation in packed soil column flow-through systems ENVIRONMENTAL POLLUTION Zhao, L., Lu, X., Polasko, A., Johnson, N. W., Miao, Y., Yang, Z., Mahendra, S., Gu, B. 2018; 243: 573-581

  Abstract

  Biodegradation of 1,4-dioxane was examined in packed quartz and soil column flow-through systems. The inhibitory effects of co-contaminants, specifically trichloroethene (TCE), 1,1-dichloroethene (1,1-DCE), and copper (Cu2+) ions, were investigated in the columns either with or without bioaugmentation with a 1,4-dioxane degrading bacterium Pseudonocardia dioxanivorans CB1190. Results indicate that CB1190 cells readily grew and colonized in the columns, leading to significant degradation of 1,4-dioxane under oxic conditions. Degradation of 1,4-dioxane was also observed in the native soil (without bioaugmentation), which had been previously subjected to enhanced reductive dechlorination treatment for co-contaminants TCE and 1,1-DCE. Bioaugmentation of the soil with CB1190 resulted in nearly complete degradation at influent concentrations of 3-10 mg L-1 1,4-dioxane and a residence reaction time of 40-80 h, but the presence of co-contaminants, 1,1-DCE and Cu2+ ions (up to 10 mg L-1), partially inhibited 1,4-dioxane degradation in the untreated and bioaugmented soil columns. However, the inhibitory effects were much less severe in the column flow-through systems than those previously observed in planktonic cultures, which showed near complete inhibition at the same co-contaminant concentrations. These observations demonstrate a low susceptibility of soil microbes to the toxicity of 1,1-DCE and Cu2+ in packed soil flow-through systems, and thus have important implications for predicting biodegradation potential and developing sustainable, cost-effective technologies for in situ remediation of 1,4-dioxane contaminated soils and groundwater.

  View details for DOI 10.1016/j.envpol.2018.09.018

  View details for Web of Science ID 000449891800062

  View details for PubMedID 30216889

• Development of bioreactors for comparative study of natural attenuation, biostimulation, and bioaugmentation of petroleum-hydrocarbon contaminated soil JOURNAL OF HAZARDOUS MATERIALS Safdari, M., Kariminia, H., Rahmati, M., Fazlollahi, F., Polasko, A., Mahendra, S., Wilding, W., Fletcher, T. H. 2018; 342: 270-278

  Abstract

  Bioremediation of soil and groundwater sites contaminated by petroleum hydrocarbons is known as a technically viable, cost-effective, and environmentally sustainable technology. The purpose of this study is to investigate laboratory-scale bioremediation of petroleum-hydrocarbon contaminated soil through development of eight bioreactors, two bioreactors for each bioremediation mode. The modes were: (1) natural attenuation (NA); (2) biostimulation (BS) with oxygen and nutrients; (3) bioaugmentation (BA) with hydrocarbon degrading isolates; (4) a combination of biostimulation and bioaugmentation (BS-BA). Total petroleum hydrocarbons (TPH) mass balance over the bioreactors showed about 2% of initial 20,000mgkg-soil-1 TPH was removed by advection due to synthetic groundwater which was flowing through the soil, and the rest of decrease in TPH was caused by biodegradation. The BS-BA mode showed the highest TPH biodegradation percentage (89.7±0.3%) compared to the NA (51.4±0.6%), BS (81.9±0.3%) and BA (62.9±0.5%) modes. Furthermore, an increase in microbial population was another evidence of TPH biodegradation by microorganism. Reaction rate data from each bioremediation mode were fitted with a first-order reaction rate model. The Monod kinetic constants including maximum specific growth rate of microorganisms (μmax) and substrate concentration at half-velocity constant (Ks) were estimated for each bioremediation modes.

  View details for DOI 10.1016/j.jhazmat.2017.08.044

  View details for Web of Science ID 000414880800029

  View details for PubMedID 28843796

• Effects of Sulfate Reduction on Trichloroethene Dechlorination by Dehalococcoides-Containing Microbial Communities APPLIED AND ENVIRONMENTAL MICROBIOLOGY Mao, X., Polasko, A., Alvarez-Cohen, L. 2017; 83 (8)

  Abstract

  In order to elucidate interactions between sulfate reduction and dechlorination, we systematically evaluated the effects of different concentrations of sulfate and sulfide on reductive dechlorination by isolates, constructed consortia, and enrichments containing Dehalococcoides sp. Sulfate (up to 5 mM) did not inhibit the growth or metabolism of pure cultures of the dechlorinator Dehalococcoides mccartyi 195, the sulfate reducer Desulfovibrio vulgaris Hildenborough, or the syntroph Syntrophomonas wolfei In contrast, sulfide at 5 mM exhibited inhibitory effects on growth of the sulfate reducer and the syntroph, as well as on both dechlorination and growth rates of D. mccartyi Transcriptomic analysis of D. mccartyi 195 revealed that genes encoding ATP synthase, biosynthesis, and Hym hydrogenase were downregulated during sulfide inhibition, whereas genes encoding metal-containing enzymes involved in energy metabolism were upregulated even though the activity of those enzymes (hydrogenases) was inhibited. When the electron acceptor (trichloroethene) was limiting and an electron donor (lactate) was provided in excess to cocultures and enrichments, high sulfate concentrations (5 mM) inhibited reductive dechlorination due to the toxicity of generated sulfide. The initial cell ratio of sulfate reducers to D. mccartyi (1:3, 1:1, or 3:1) did not affect the dechlorination performance in the presence of sulfate (2 and 5 mM). In contrast, under electron donor limitation, dechlorination was not affected by sulfate amendments due to low sulfide production, demonstrating that D. mccartyi can function effectively in anaerobic microbial communities containing moderate sulfate concentrations (5 mM), likely due to its ability to outcompete other hydrogen-consuming bacteria and archaea.IMPORTANCE Sulfate is common in subsurface environments and has been reported as a cocontaminant with chlorinated solvents at various concentrations. Inconsistent results for the effects of sulfate inhibition on the performance of dechlorination enrichment cultures have been reported in the literature. These inconsistent findings make it difficult to understand potential mechanisms of sulfate inhibition and complicate the interpretation of bioremediation field data. In order to elucidate interactions between sulfate reduction and reductive dechlorination, this study systematically evaluated the effects of different concentrations of sulfate and sulfide on reductive dechlorination by isolates, constructed consortia, and enrichments containing Dehalococcoides sp. This study provides a more fundamental understanding of the competition mechanisms between reductive dechlorination by Dehalococcoides mccartyi and sulfate reduction during the bioremediation process. It also provides insights on the significance of sulfate concentrations on reductive dechlorination under electron donor/acceptor-limiting conditions during in situ bioremediation applications. For example, at a trichloroethene-contaminated site with a high sulfate concentration, proper slow-releasing electron donors can be selected to generate an electron donor-limiting environment that favors reductive dechlorination and minimizes the sulfide inhibition effect.

  View details for DOI 10.1128/AEM.03384-16

  View details for Web of Science ID 000398771200018

  View details for PubMedID 28159790

  View details for PubMedCentralID PMC5377507

• Efficient Metabolic Exchange and Electron Transfer within a Syntrophic Trichloroethene-Degrading Coculture of Dehalococcoides mccartyi 195 and Syntrophomonas wolfei APPLIED AND ENVIRONMENTAL MICROBIOLOGY Mao, X., Stenuit, B., Polasko, A., Alvarez-Cohen, L. 2015; 81 (6): 2015-2024

  Abstract

  Dehalococcoides mccartyi 195 (strain 195) and Syntrophomonas wolfei were grown in a sustainable syntrophic coculture using butyrate as an electron donor and carbon source and trichloroethene (TCE) as an electron acceptor. The maximum dechlorination rate (9.9 ± 0.1 μmol day(-1)) and cell yield [(1.1 ± 0.3) × 10(8) cells μmol(-1) Cl(-)] of strain 195 maintained in coculture were, respectively, 2.6 and 1.6 times higher than those measured in the pure culture. The strain 195 cell concentration was about 16 times higher than that of S. wolfei in the coculture. Aqueous H2 concentrations ranged from 24 to 180 nM during dechlorination and increased to 350 ± 20 nM when TCE was depleted, resulting in cessation of butyrate fermentation by S. wolfei with a theoretical Gibbs free energy of -13.7 ± 0.2 kJ mol(-1). Carbon monoxide in the coculture was around 0.06 μmol per bottle, which was lower than that observed for strain 195 in isolation. The minimum H2 threshold value for TCE dechlorination by strain 195 in the coculture was 0.6 ± 0.1 nM. Cell aggregates during syntrophic growth were observed by scanning electron microscopy. The interspecies distances to achieve H2 fluxes required to support the measured dechlorination rates were predicted using Fick's law and demonstrated the need for aggregation. Filamentous appendages and extracellular polymeric substance (EPS)-like structures were present in the intercellular spaces. The transcriptome of strain 195 during exponential growth in the coculture indicated increased ATP-binding cassette transporter activities compared to the pure culture, while the membrane-bound energy metabolism related genes were expressed at stable levels.

  View details for DOI 10.1128/AEM.03464-14

  View details for Web of Science ID 000350554800016

  View details for PubMedID 25576615

  View details for PubMedCentralID PMC4345365

• Using electron balances and molecular techniques to assess trichoroethene-induced shifts to a dechlorinating microbial community BIOTECHNOLOGY AND BIOENGINEERING Ziv-El, M., Popat, S. C., Parameswaran, P., Kang, D., Polasko, A., Halden, R. U., Rittmann, B. E., Krajmalnik-Brown, R. 2012; 109 (9): 2230-2239

  Abstract

  This study demonstrated the utility in correlating performance and community structure of a trichloroethene (TCE)-dechlorinating microbial consortium; specifically dechlorinators, fermenters, homoacetogens, and methanogens. Two complementary approaches were applied: predicting trends in the microbial community structure based on an electron balance analysis and experimentally assessing the community structure via pyrosequencing and quantitative polymerase chain reaction (qPCR). Fill-and-draw reactors inoculated with the DehaloR^2 consortium were operated at five TCE-pulsing rates between 14 and 168 µmol/10-day-SRT, amended with TCE every 2 days to give peak concentrations between 0.047 and 0.56 mM (6-74 ppm) and supplied lactate and methanol as sources of e(-) donor and carbon. The complementary approaches demonstrated the same trends: increasing abundance of Dehalococcoides and Geobacter and decreasing abundance of Firmicutes with increasing TCE pulsing rate, except for the highest pulsing rate. Based on qPCR, the abundance of Geobacter and Dehalococcoides decreased for the highest TCE pulsing rate, and pyrosequencing showed this same trend for the latter. This deviation suggested decoupling of Dehalococcoides growth from dechlorination. At pseudo steady-state, methanogenesis was minimal for all TCE pulsing rates. Pyrosequencing and qPCR showed suppression of the homoacetogenic genera Acetobacterium at the two highest pulsing rates, and it was corroborated by a decreased production of acetate from lactate fermentation and increased propionate production. Suppression of Acetobacterium, which can provide growth factors to Dehalococcoides, may have contributed to the decoupling for the highest TCE-pulsing rate.

  View details for DOI 10.1002/bit.24504

  View details for Web of Science ID 000306759500007

  View details for PubMedID 22447387