DSpace Repository :: Browsing by Author "Rao, Shreyas S."

Browsing by Author "Rao, Shreyas S."

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Bioengineered models to study tumor dormancy
(BMC, 2019) Rao, Shreyas S.; Kondapaneni, Raghu Vamsi; Narkhede, Akshay A.; University of Alabama Tuscaloosa
The onset of cancer metastasis is the defining event in cancer progression when the disease is considered lethal. The ability of metastatic cancer cells to stay dormant for extended time periods and reawaken at later stages leading to disease recurrence makes treatment of metastatic disease extremely challenging. The tumor microenvironment plays a critical role in deciding the ultimate fate of tumor cells, yet the mechanisms by which this occurs, including dormancy, is not well understood. This mini-review discusses bioengineered models inspired from tissue engineering strategies that mimic key aspects of the tumor microenvironment to study tumor dormancy. These models include biomaterial based three dimensional models, microfluidic based models, as well as bioreactor based models that incorporate relevant microenvironmental components such as extracellular matrix molecules, niche cells, or their combination to study microenvironmental regulation of tumor dormancy. Such biomimetic models provide suitable platforms to investigate the dormant niche, including cues that drive the dormant to proliferative transition in cancer cells. In addition, the potential of such model systems to advance research in the field of tumor dormancy is discussed.
Biomaterial Scaffolds as Pre-metastatic Niche Mimics Systemically Alter the Primary Tumor and Tumor Microenvironment
(Wiley, 2018) Aguado, Brian A.; Hartfield, Rachel M.; Bushnell, Grace G.; Decker, Joseph T.; Azarin, Samira M.; Nanavati, Dhaval; Schipma, Matthew J.; Rao, Shreyas S.; Oakes, Robert S.; Zhang, Yining; Jeruss, Jacqueline S.; Shea, Lonnie D.; Northwestern University; University of Michigan; University of Alabama Tuscaloosa
Primary tumor (PT) immune cells and pre-metastatic niche (PMN) sites are critical to metastasis. Recently, synthetic biomaterial scaffolds used as PMN mimics are shown to capture both immune and metastatic tumor cells. Herein, studies are performed to investigate whether the scaffold-mediated redirection of immune and tumor cells would alter the primary tumor microenvironment (TME). Transcriptomic analysis of PT cells from scaffold-implanted and mock-surgery mice identifies differentially regulated pathways relevant to invasion and metastasis progression. Transcriptomic differences are hypothesized to result from scaffold-mediated modulations of immune cell trafficking and phenotype in the TME. Culturing tumor cells with conditioned media generated from PT immune cells of scaffold-implanted mice decrease invasion in vitro more than two-fold relative to mock surgery controls and reduce activity of invasion-promoting transcription factors. Secretomic characterization of the conditioned media delineates interactions between immune cells in the TME and tumor cells, showing an increase in the pan-metastasis inhibitor decorin and a concomitant decrease in invasion-promoting chemokine (C-C motif) ligand 2 (CCL2) in scaffold-implanted mice. Flow cytometric and transcriptomic profiling of PT immune cells identify phenotypically distinct tumor-associated macrophages (TAMs) in scaffold-implanted mice, which may contribute to an invasion-suppressive TME. Taken together, this study demonstrates biomaterial scaffolds systemically influence metastatic progression through manipulation of the TME.
Development and Applications of Opioids Alternatives for Pain Management
(University of Alabama Libraries, 2024) Li, Qi; Zhao, Chao
This dissertation explores alternative pain management strategies to opioids, focusing on tetrodotoxin (TTX) and capsaicin as novel anesthetics. Acute post-surgical pain typically lasts 5-7 days, while long-term pain management can span up to 12 weeks. Opioids are commonly used but are linked to serious side effects, including addiction, nausea, cognitive impairment, and fatal overdoses. TTX is a site-1 sodium channel blocker, nearly 1000 times more potent than conventional amino-amide and amino-ester local anesthetics, and it lacks the myotoxicity and nerve toxicity often associated with these anesthetics. However, its systemic distribution can cause fatal diaphragm paralysis. To limit this, drug delivery systems were developed to refine the release kinetics of TTX. Initially, a hydration-induced void-containing hydrogel system was created to encapsulate TTX physically. Following a simple hydration process between the polymer and the TTX solution, TTX was successfully encapsulated in voids shielded by densely packed polymer, achieving 100% encapsulation efficiency. These injectable hydrogels can be stored for several months without compromising drug encapsulation and release properties. A single injection of the hydrogel/TTX formulation produced a sciatic nerve block lasting up to 10 hours.Despite progress, the duration of nerve blockade remains insufficient for clinical needs. The physical encapsulation method limits TTX dosage due to unstable release kinetics. Therefore, polymer-TTX conjugates were developed by chemically conjugating TTX to the polymer backbone and releasing it through ester bond hydrolysis. This increased the TTX dosage nearly 40-fold, prolonging the nerve blockade to more than three days.Finally, a galacturonic acid-capsaicin prodrug was developed. Capsaicin, the active component of chili peppers, selectively targets the transient receptor potential vanilloid-1 (TRPV1) receptor to block nociceptive signaling without affecting motor nerves. The prodrug utilized facilitated transport by glucose transporters across the perineurium, eliminating the side effects typically caused by capsaicin, such as burning pain, seizures, and respiratory depression. A single injection at the sciatic nerves of rats resulted in nociceptive-selective nerve blockade lasting 10 days with minimal tissue toxicity or side effects.This research aims to address the limitations of traditional pain management methods and pave the way for safer, more effective pain management solutions that could benefit patients suffering from postoperative pain.
Editorial: Biological Delivery: Bridging Fundamental Research With the Clinic and Industry
(Frontiers, 2022) Ruan, Gang; Huang, Peng; Mei, Lin; Rao, Shreyas S.; Shenzhen University; Sun Yat Sen University; University of Alabama Tuscaloosa
The effects of physiological fluid shear stress on circulating tumor cells
(University of Alabama Libraries, 2018) Triantafillu, Ursula Lea; Kim, Yonghyun; University of Alabama Tuscaloosa
The focus of this dissertation is on the effects of physiological fluid shear stress (FSS) on circulating tumor cells (CTCs). FSS occurs on cells both in vitro and in vivo. FSS is typically considered as a major variable in large scale bioprocessing while FSS is assumed to have a negligible role in bench scale culture. In physiological settings, FSS impacts cells in cancer where local, regional, and distant cancers experience FSS through interstitial, lymphatic, and hematological flow, respectively. CTCs in hematological flow experience the highest FSS and are involved in the transit stage of metastasis. One challenge of metastatic cancer is the lack of secondary tumor detection. Detection of CTCs largely relies on the epithelial cell adhesion molecule (EpCAM). CTC phenotype also includes expression of cancer stem cell (CSC) and epithelial to mesenchymal transition (EMT), which are correlated to increased resistance to chemotherapy. The study of FSS using an in vitro model can provide a better understanding on CTC phenotype expression and drug resistance. FSS was first examined using a baseline study with in vitro cell spheroid culture. Spheroids provide better representation of the stem and tumor cell environment than 2D culture. These cells experience FSS during cell dissociation. Since FSS can detrimentally affect cells, a gentler mechanical platform was developed for dissociation. Furthermore, this method, as well as traditional dissociation methods, was tested to study how FSS affects cell viability and expression. This platform was further used to model breast CTCs as suspension cells under FSS. This metastatic model allowed for testing the effects of FSS on CTC phenotype, and it was found that FSS increased CSC and CTC expression. Since an increase in CSC expression is correlated to increased drug resistance, drug resistance on CTCs under FSS was tested with chemotherapy drugs. It was found that the combination of FSS and drug resistance synergistically increases drug resistance expression in the model CTCs, corroborating clinical reports of CTC drug resistance. Finally, the effects of FSS and drug resistance was tested on estrogen receptor positive (ER+) molecular subtype. Collectively, these studies provide a better understanding on CTC behavior during metastasis.
Engineering the pre-metastatic niche
(Nature Portfolio, 2017) Aguado, Brian A.; Bushnell, Grace G.; Rao, Shreyas S.; Jeruss, Jacqueline S.; Shea, Lonnie D.; Northwestern University; University of Michigan; University of Alabama Tuscaloosa
The pre-metastatic niche -the accumulation of aberrant immune cells and extracellular-matrix proteins in target organs primes the initially healthy organ microenvironment and renders it amenable for subsequent colonization by metastatic cancer cells. By attracting metastatic cells, mimics of the pre-metastatic niche offer both diagnostic and therapeutic potential. However, deconstructing the complexity of the niche by identifying the interactions between cell populations as well as the mediatory roles of the immune system, soluble factors, extracellular-matrix proteins and stromal cells has proved challenging. Experimental models are needed to recapitulate niche-population biology in situ and to mediate in vivo tumour-cell homing, colonization and proliferation. In this Review, we outline the biology of the pre-metastatic niche and discuss advances in the engineering of niche-mimicking biomaterials that regulate the behaviour of tumour cells at an implant site. Such 'oncomaterials' offer strategies for the early detection of metastatic events, the inhibition of the formation of the pre-metastatic niche and the attenuation of metastatic progression.
Enhanced Survival with Implantable Scaffolds That Capture Metastatic Breast Cancer Cells In Vivo
(American Association of Cancer Research, 2016) Rao, Shreyas S.; Bushnell, Grace G.; Azarin, Samira M.; Spicer, Graham; Aguado, Brian A.; Stoehr, Jenna R.; Jiang, Eric J.; Backman, Vadim; Shea, Lonnie D.; Jeruss, Jacqueline S.; University of Alabama Tuscaloosa; University of Michigan; University of Minnesota Twin Cities; Northwestern University; University of Colorado Boulder
The onset of distant organ metastasis from primary breast cancer marks the transition to a stage IV diagnosis. Standard imaging modalities often detect distant metastasis when the burden of disease is high, underscoring the need for improved methods of detection to allow for interventions that would impede disease progression. Here, microporous poly(e-caprolactone) scaffolds were developed that capture early metastatic cells and thus serve as a sentinel for early detection. These scaffolds were used to characterize the dynamic immune response to the implant spanning the acute and chronic foreign body response. The immune cell composition had stabilized at the scaffold after approximately 1 month and changed dramatically within days to weeks after tumor inoculation, with CD11b(+)Gr1(hi)Ly6C(-) cells having the greatest increase in abundance. Implanted scaffolds recruited metastatic cancer cells that were inoculated into the mammary fat pad in vivo, which also significantly reduced tumor burden in the liver and brain. Additionally, cancer cells could be detected using a label-free imaging modality termed inverse spectroscopic optical coherence tomography, and we tested the hypothesis that subsequent removal of the primary tumor after early detection would enhance survival. Surgical removal of the primary tumor following cancer cell detection in the scaffold significantly improved disease-specific survival. The enhanced disease-specific survival was associated with a systemic reduction in the CD11b(+)Gr1(hi)Ly6C(-) cells as a consequence of the implant, which was further supported by Gr-1 depletion studies. Implementation of the scaffold may provide diagnostic and therapeutic options for cancer patients in both the high-risk and adjuvant treatment settings. (C) 2016 AACR.
Extracellular matrix mediators of metastatic cell colonization characterized using scaffold mimics of the pre-metastatic niche
(Elsevier, 2016) Aguado, Brian A.; Gaffe, Jordan R.; Nanavati, Dhaval; Rao, Shreyas S.; Bushnell, Grace G.; Azarin, Samira M.; Shea, Lonnie D.; Northwestern University; University of Alabama Tuscaloosa; University of Michigan; University of Minnesota Twin Cities
Metastatic tumor cells colonize the pre-metastatic niche, which is a complex microenvironment consisting partially of extracellular matrix (ECM) proteins. We sought to identify and validate novel contributors to tumor cell colonization using ECM-coated poly(epsilon-caprolactone) (PCL) scaffolds as mimics of the pre metastatic niche. Utilizing orthotopic breast cancer mouse models, fibronectin and collagen IV-coated scaffolds implanted in the subcutaneous space captured colonizing tumor cells, showing a greater than 2-fold increase in tumor cell accumulation at the implant site compared to uncoated scaffolds. As a strategy to identify additional ECM colonization contributors, decellularized matrix (DCM) from lungs and livers containing metastatic tumors were characterized. In vitro, metastatic cell adhesion was increased on DCM coatings from diseased organs relative to healthy DCM. Furthermore, in vivo implantations of diseased DCM-coated scaffolds had increased tumor cell colonization relative to healthy DCM coatings. Mass-spectrometry proteomics was performed on healthy and diseased DCM to identify candidates associated with colonization. Myeloperoxidase was identified as abundantly present in diseased organs and validated as a contributor to colonization using myeloperoxidase-coated scaffold implants. This work identified novel ECM proteins associated with colonization using decellularization and proteomics techniques and validated candidates using a scaffold to mimic the pre-metastatic niche. Statement of Significance The pre-metastatic niche consists partially of ECM proteins that promote metastatic cell colonization to a target organ. We present a biomaterials-based approach to mimic this niche and identify ECM mediators of colonization. Using murine breast cancer models, we implanted microporous PCL scaffolds to recruit colonizing tumor cells in vivo. As a strategy to modulate colonization, we coated scaffolds with various ECM proteins, including decellularized lung and liver matrix from tumor-bearing mice. After characterizing the organ matrices using proteomics, myeloperoxidase was identified as an ECM protein contributing to colonization and validated using our scaffold. Our scaffold provides a platform to identify novel contributors to colonization and allows for the capture of colonizing tumor cells for a variety of downstream clinical applications. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
High Frequency Spectral Ultrasound Imaging to Detect Metastasis in Implanted Biomaterial Scaffolds
(Springer, 2020) Bushnell, Grace G.; Hong, Xiaowei; Hartfield, Rachel M.; Zhang, Yining; Oakes, Robert S.; Rao, Shreyas S.; Jeruss, Jacqueline S.; Stegemann, Jan P.; Deng, Cheri X.; Shea, Lonnie D.; University of Michigan; University of Alabama Tuscaloosa
For most cancers, metastasis is the point at which disease is no longer curable. Earlier detection of metastasis, when it is undetectable by current clinical methods, may enable better outcomes. We have developed a biomaterial implant that recruits metastatic cancer cells in mouse models of breast cancer. Here, we investigate spectral ultrasound imaging (SUSI) as a non-invasive strategy for detecting metastasis to the implanted biomaterial scaffolds. Our results show that SUSI, which detects parameters related to tissue composition and structure, identified changes at an early time point when tumor cells were recruited to scaffolds in orthotopic breast cancer mouse models. These changes were not associated with acellular components in the scaffolds but were reflected in the cellular composition in the scaffold microenvironment, including an increase in CD31 + CD45- endothelial cell number in tumor bearing mice. In addition, we built a classification model based on changes in SUSI parameters from scaffold measurements to stratify tumor free and tumor bearing status. Combination of a linear discriminant analysis and bagged decision trees model resulted in an area under the curve of 0.92 for receiver operating characteristics analysis. With the potential for early non-invasive detection, SUSI could facilitate clinical translation of the scaffolds for monitoring metastatic disease.
The Impact of Astrocytes and Endothelial Cells on Glioblastoma Stemness Marker Expression in Multicellular Spheroids
(Springer, 2021) Nakod, Pinaki S.; Kim, Yonghyun; Rao, Shreyas S.; University of Alabama Tuscaloosa
Introduction Glioblastoma multiforme (GBM), the most common primary brain tumor in adults, is extremely malignant and lethal. GBM tumors are highly heterogenous, being comprised of cellular and matrix components, which contribute to tumor cell invasion, cancer stem cell maintenance, and drug resistance. Here, we developed a heterotypic 3D spheroid model integrating GBM cells with astrocytes and endothelial cells (ECs) to better simulate the cellular components of the tumor microenvironment and investigate their impact on the stemness marker expression of GBM cells, which has not been previously investigated. Methods We used U87 GBM cells, C8-D1A mouse astrocytes, and human umbilical vein ECs to construct co- and tri-culture spheroid models in low-attachment U-well plates. We characterized the expression of known stemness markers NESTIN, SOX2, CD133, NANOG, and OCT4 in these models and compared it to respective mixed monoculture spheroids (control) using qRT-PCR and immunostaining. Results We incorporated GBM cells and astrocytes/ECs in 1:1, 1:2, 1:4, and 1:9 ratio and observed spontaneous self-assembled spheroids in all coculture conditions. We observed changing spheroid size dynamics over 7 days and an increased expression in stemness markers in GBM-astrocyte and GBM-EC coculture spheroids in 1:4 and 1:9 coculture conditions, respectively. In a triculture model employing GBM cells, astrocytes, and ECs in a 1:4:9 ratio, we found an increased expression of all the stemness markers. Conclusions We elucidated the impact of astrocytes and ECs on GBM stemness marker expression. This multicellular spheroid model may provide an important tool for investigating the crosstalk between cell types in GBM.
Microporous scaffolds loaded with immunomodulatory lentivirus to study the contribution of immune cell populations to tumor cell recruitment in vivo
(Wiley, 2020) Bushnell, Grace G.; Rao, Shreyas S.; Hartfield, Rachel M.; Zhang, Yining; Oakes, Robert S.; Jeruss, Jacqueline S.; Shea, Lonnie D.; University of Michigan; University of Alabama Tuscaloosa
Metastases are preceded by stochastic formation of a hospitable microenvironment known as the premetastatic niche, which has been difficult to study. Herein, we employ implantable polycaprolactone scaffolds as an engineered premetastatic niche to independently investigate the role of interleukin-10 (IL10), CXCL12, and CCL2 in recruiting immune and tumor cells and impacting breast cancer cell phenotype via lentiviral overexpression. Lentivirus delivered from scaffolds in vivo achieved sustained transgene expression for 56 days. IL10 lentiviral expression, but not CXCL12 or CCL2, significantly decreased tumor cell recruitment to scaffolds in vivo. Delivery of CXCL12 enhanced CD45+ immune cell recruitment to scaffolds while delivery of IL10 reduced immune cell recruitment. CCL2 did not alter immune cell recruitment. Tumor cell phenotype was investigated using conditioned media from immunomodulated scaffolds, with CXCL12 microenvironments reducing proliferation, and IL10 microenvironments enhancing proliferation. Migration was enhanced with CCL2 and reduced with IL10-driven microenvironments. Multiple linear regression identified populations of immune cells associated with tumor cell abundance. CD45+ immune and CD8+ T cells were associated with reduced tumor cell abundance, while CD11b+Gr1+ neutrophils and CD4+ T cells were associated with enhanced tumor cell abundance. Collectively, biomaterial scaffolds provide a tool to probe the formation and function of the premetastatic niche.
Secretome identification of immune cell factors mediating metastatic cell homing
(Nature Portfolio, 2015) Aguado, Brian A.; Wu, Jia J.; Azarin, Samira M.; Nanavati, Dhaval; Rao, Shreyas S.; Bushnell, Grace G.; Medicherla, Chaitanya B.; Shea, Lonnie D.; Northwestern University; University of Minnesota Twin Cities; University of Alabama Tuscaloosa; University of Michigan; Feinberg School of Medicine
Metastatic cell homing is a complex process mediated in part by diffusible factors secreted from immune cells found at a pre-metastatic niche. We report on connecting secretomics and TRanscriptional Activity CEll aRray (TRACER) data to identify functional paracrine interactions between immune cells and metastatic cells as novel mediators of homing. Metastatic breast cancer mouse models were used to generate a diseased splenocyte conditioned media (D-SCM) containing immune cell secreted factors. MDA-MB-231 metastatic cell activity including cell invasion, migration, transendothelial migration, and proliferation were increased in D-SCM relative to control media. Our D-SCM secretome analysis yielded 144 secreted factor candidates that contribute to increased metastatic cell activity. The functional mediators of homing were identified using MetaCore software to determine interactions between the immune cell secretome and the TRACER-identified active transcription factors within metastatic cells. Among the 5 candidate homing factors identified, haptoglobin was selected and validated in vitro and in vivo as a key mediator of homing. Our studies demonstrate a novel systems biology approach to identify functional signaling factors associated with a cellular phenotype, which provides an enabling tool that complements large-scale protein identification provided by proteomics.
Shape dependent iron oxide nanoparticles for simultaneous imaging and therapy
(University of Alabama Libraries, 2018) Sherwood, Jennifer; Bao, Yuping; University of Alabama Tuscaloosa
The primary focus of this dissertation is to explore the use of shape dependent iron oxide nanoparticles as magnetic resonance imaging contrast agents. In addition to biocompatibility, nanoparticles provide a foundation for implementing imaging guided drug delivery systems. We begin with the synthesis of iron oxide nanoparticles of varying sizes and shapes. Specifically, large (>4 nm) spherical particles, ultrasmall (<4 nm) nanoparticles, and ultrathin (2x20 nm) nanowires were synthesized by thermal decomposition of an iron oleate precursor. To render the nanoparticles biologically compatible, a phase transfer step was necessary to transfer nanoparticles from organic solvents aqueous phase. Insufficient or incomplete ligand exchange of the ultrasmall nanoparticles could result in aggregation and a loss of the paramagnetic properties. Here we were able to successfully coat the nanoparticles with several biologically compatible ligands while maintaining the paramagnetic properties for T1 MRI contrast agents. Furthermore, we explored the cellular uptake behaviors of the subnanometer ultrasmall nanoparticles and ultrathin nanowires. The nanoparticles were functionalized with tannic acid and incubated with HepG2 cells. The shape dependent cellular uptake was quantified, and the ultrasmall nanoparticles exhibited a much higher cellular uptake than the ultrathin nanowires. The high cellular uptake of the ultrasmall nanoparticles may be ideal for stem cell labelling, however the low blood circulation time (<15 min) limited their use, in vivo. In order to increase the circulation time, the size must be increased without altering the magnetic properties of the nanoparticles. Therefore, the ultrasmall nanoparticles were trapped in a bovine serum albumin matrix using protein desolvation. Using the protein matrix, nanoparticles were clustered together, free from aggregation, in a water rich environment allowing for the clusters to maintain the positive, T1 contrast. Encapsulation of the nanoparticles in proteins increased the in vivo blood circulation time from 15 min to over 2 hours. Finally, we demonstrated that both small molecule and protein drugs may be loaded into the clusters. The drug loading and release was studied using fluorescent dyes as a model. The drugs could be released through two mechanisms, enzymatic degradation, or physically released using ultrasound. These studies open up the possibility to both deliver drugs to targeted locations, as well as monitor the distribution, localization, and release of the drugs, noninvasively, in vivo, using MRI.
Synergistic effect of eribulin and CDK inhibition for the treatment of triple negative breast cancer
(Impact Journals, 2017) Rao, Shreyas S.; Stoehr, Jenna; Dokic, Danijela; Wan, Lei; Decker, Joseph T.; Konopka, Kristine; Thomas, Alexandra L.; Wu, Jia; Kaklamani, Virginia G.; Shea, Lonnie D.; Jeruss, Jacqueline S.; University of Alabama Tuscaloosa; Northwestern University; University of Michigan; University of Texas Health Science Center at San Antonio
Activation of CDK2 in triple negative breast cancer (TNBC) can contribute to non-canonical phosphorylation of a TGF beta signaling component, Smad3, promoting cell proliferation and migration. Inhibition of CDK2 was shown to decrease breast cancer oncogenesis. Eribulin chemotherapy was used effectively in the treatment of TNBC. To this end, we tested therapeutic efficacy of a novel CDK2/9 inhibitor, CYC065, eribulin, and the combination of CYC065 and eribulin in 3 different TNBC cell lines, and an in vivo xenograft model. Specifically, we characterized cell proliferation, apoptosis, migration, cell cycle associated protein expression, treatment-related transcription factor activity, and tumor growth in TNBC. Treatment with CYC065 and eribulin in combination had a superior effect on decreasing cell proliferation, inducing apoptosis, and inhibiting migration in TNBC cell lines in vitro. Combination therapy inhibited non-canonical Smad3 phosphorylation at the T179 site in the protein linker region, and resulted in increased p15 and decreased c-myc expression. In a transcription factor array, combination treatment significantly increased activity of AP1 and decreased activity of factors including NF kappa B, SP1, E2F, and SMAD3. In an in vivo xenograft model of TNBC, individual and combination treatments resulted in a decrease in both tumor volume and mitotic indices. Taken together, these studies highlight the potential of this novel drug combination, CYC065 and eribulin, to suppress the growth of TNBC cells in vitro and in vivo, warranting further clinical investigation.
Targeting Hyaluronan Interactions for Glioblastoma Stem Cell Therapy
(Springer, 2019) Hartheimer, Joline S.; Park, Seungjo; Rao, Shreyas S.; Kim, Yonghyun; University of Alabama Tuscaloosa
Even with rigorous treatments, glioblastoma multiforme (GBM) has an abysmal median survival rate, greatly due to the drug-resistant glioblastoma stem cell (GSC) population. GSCs are known to remodel their microenvironment, but the precise role of extracellular matrix components hyaluronic acid (HA) and hyaluronidases (HAases) on the GSC population is still largely unknown. Our objective was to determine how HAase can sensitize GSCs to chemotherapy drugs by disrupting the HA-CD44 signaling. GBM cell line U87-MG and patient-derived D456 cells were grown in GSC-enriching media and treated with HA or HAase. Expressions of GSC markers, HA-related genes, and drug resistance genes were measured via flow cytometry, confocal microscopy, and qRT-PCR. Proliferation after combined HAase and temozolomide (TMZ) treatment was measured via WST-8. HA supplementation promoted the expression of GSC markers and CD44 in GBM cells cultured in serum-free media. Conversely, HAase addition inhibited GSC gene expression while promoting CD44 expression. Finally, HAase sensitized GBM cells to TMZ. We propose a combined treatment of HAase and chemotherapy drugs by disrupting the stemness-promoting HA to target GSCs. This combination therapy shows promise even when temozolomide treatment alone causes resistance.

Browsing by Author "Rao, Shreyas S."

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