Prostate cancer (PCa) at the bone metastatic stage remains a global health challenge with low survival rates. This study aimed to identify therapeutic microRNAs (miRNAs) for delivery by calcium phosphate nanoparticles (CaP-NPs) to modify transcript profiles in PCa. Microarray analysis identified miR-205-5p as differentially downregulated in PCa bone metastatic cells (PC-3). CaP-NPs containing mimetic molecules of miR-205-5p were successfully prepared. Particles were spherical, sterile, and homogeneous and measured approximately 50 nm. CaP-NPs efficiently delivered miR-205-5p to cells, restoring its expression and inducing cell death. Transcript levels of the target genes AR, BAMBI, SMAD1/5/9, VEGFA, and ZEB1 decreased following miR-205-5p delivery. Live-cell imaging demonstrated the uptake of CaP-NPs in both two-dimensional (PC3-cells monolayer culture) and three-dimensional (C4-2B-derived microtumor) cancer models. The three-dimensional model was produced in a microwell system inoculated with C4-2B cells, which readily form microtumors resembling disseminated PCa cells. Collectively, these results confirm miR-205-5p as a tumor suppressor in bone metastatic PCa cells and suggest that CaP-NPs could be a promising delivery system for further preclinical exploration in gene therapy targeting bone metastatic PCa.

The development of non-invasive, non-ionizing sensitive molecular targeting approaches to detect colorectal cancer (CRC) lesions is warranted to improve high risk patient outcomes. Hyperpolarized silicon nanoparticles and microparticles are potentially well-suited to act as targeted molecular imaging agents because of their overall biocompatibility and long-lasting enhanced magnetic resonance imaging (MRI) signals. In this study, dynamic nuclear polarization was performed on silicon particles functionalized with an antibody to Mucin-1 (MUC1), a surface mucin glycoprotein aberrantly expressed in CRC. Antibody conjugation to the particle surface did not affect 29 Si hyperpolarization characteristics. Similarly, conjugation and the dynamic nuclear polarization process did not adversely affect the affinity of the targeting antibody. In vivo MRI scans performed 10-15 minutes after luminal administration of targeted hyperpolarized particles into human MUC1-expressing orthotopic CRC mouse models showed that particles actively targeted tumor sites. These results were supported by chemical and biological controls and blocking experiments as well as correlative immunohistochemical analysis. These surface-functionalized silicon particles are under development as a platform technology that will allow non-invasive molecular targeting of CRC using hyperpolarized MRI. Single Sentence Summary:Targeted molecular MR imaging of colorectal cancer by hyperpolarized silicon particles functionalized with mucin 1 antibody.

Introduction US states eased licensing restrictions on telemedicine during the COVID-19 pandemic allowing broad use irrespective of visit type. As waivers expire, optimal uses of telemedicine must be assessed to inform policy, legislation, and clinical care. We assessed whether telemedicine visits provided the same patient experience as in-person visits, stratified by whether these were new or established patient visits, and examined the financial burden. Methods Patients from the WWAMI region (including Oregon and Hawaii, but excluding Wyoming) seen in person and via telemedicine for urologic cancer care at a major regional cancer center received a survey after their first appointment (August 2019–June 2022) on satisfaction with care, perceptions of communication during their visit, travel time, travel costs, and days of work missed. We assessed patient-reported outcomes after their visit with descriptive statistics. Results Surveys were completed for 1,031 patient visits (N=494 new patient visits, N=537 established patient visits). Satisfaction rates were high for all visit types, both new and established (mean score 59.9–60.7 [maximum 63], p>0.05). There was no difference in patient-rated quality of the encounter across visit type and modality (in-person vs. telemedicine, p>0.06 for nearly all comparisons). Patients presenting for telemedicine visits were more likely to believe that visits could be accomplished without physical exam, regardless of visit type (p <0.02). New in-person patient visits were associated with significantly higher travel costs (mean estimated visit costs $496.10, SD $1021) compared with new telemedicine visits (mean costs $26.70, SD $141p<0.001); 27% of patients receiving new in-person care required plane travel and 41% required a hotel stay (p<0.001 compared with 0.8% and 3.2% of new telemedicine patients, respectively). Conclusions Telemedicine appointments may increase access for rural-residing patients with cancer. Satisfaction outcomes among patients with urologic cancer receiving new patient telemedicine care equaled those of new patients cared for in-person; costs were markedly lower. Extending telemedicine exemptions beyond COVID-19 licensing waivers to include new patient visits would permit continued delivery of high-quality urologic cancer care to rural-residing patients. A notable limitation of this study is the large geographic breadth of the cancer center catchment compared with other areas of the US, possible limiting generalizability.

You have accessJournal of UrologyProstate Cancer: Epidemiology & Natural History II (MP68)1 May 2024MP68-05 EXCESS DEATH AND POTENTIAL LIFE YEARS LOST AMONG BLACK PROSTATE CANCER PATIENTS (1970-2020) Nana A. Frimpong, Sarah K. Holt, Daniel Carson, Yohali Burrola-Mendez, Jenney Lee, Erika Wolff, John L. Gore, and Yaw A. Nyame Nana A. FrimpongNana A. Frimpong , Sarah K. HoltSarah K. Holt , Daniel CarsonDaniel Carson , Yohali Burrola-MendezYohali Burrola-Mendez , Jenney LeeJenney Lee , Erika WolffErika Wolff , John L. GoreJohn L. Gore , and Yaw A. NyameYaw A. Nyame View All Author Informationhttps://doi.org/10.1097/01.JU.0001008744.60568.e8.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Prostate cancer demonstrates a wide and sustained disparity in mortality among Black Americans compared with the average US population. These disparities have persisted over 50 years despite significant diagnostic and therapeutic advances in prostate cancer care. We evaluated trends in excess prostate cancer mortality and excess years of potential life lost between Black and White Americans between 1970-2020. METHODS: This is a serial cross-sectional study using US national level data from CDC WONDER linked with annual life expectancy by 10-year age groups from the National Center for Health Statistics life tables for individuals aged 25-84 years. Data from non-Hispanic White and non-Hispanic Black Americans with a cause of death of prostate cancer across all age groups were included. We measured excess age-adjusted prostate cancer mortality, age-specific prostate cancer mortality, excess deaths, and excess years of potential life lost among Black vs. White Americans. RESULTS: The age-adjusted excess mortality rate increased from 21.1 to 44.8 deaths per 100,000 from 1970-1993. From 1993-2020, this rate declined from 44.8 to 18.8 excess deaths per 100,000. The annual age-adjusted mortality ratio between Black and White Americans has ranged from 2.0 to 2.5 (1980-2020) with its highest peak in 2001. The excess deaths per 100,000 Black males ranged from 1,959 to 2,522 (1980-2020) with its highest peak in 1996. The trend in excess years of potential life lost per 100,000 Black males had been steadily decreasing from 39,416 years lost in 1996 to 31,746 years lost in 2013. From 2013-2020 the excess years of potential life lost per 100,000 Black males increased from 31,746 to 39,782. The excess potential years of life lost increases with increasing age and peaks in the 65-74 years age group. CONCLUSIONS: Over a 50-year period, Black Americans have experienced more than 117,348 excess deaths due to prostate cancer resulting in 1,509,384 excess years of potential life lost in the US. Although we have seen a dramatic decrease in prostate cancer deaths since the introduction of PSA testing, Black prostate cancer patients continue to experience excess deaths which result in a loss of productivity and support (i.e., social, economic, interpersonal, etc.) for communities and families across the country. Download PPT Source of Funding: This project was made possible in part by the NCI SPORE (P50 CA097186) and the U.S. Department of Defense, Office of the Congressionally Directed Medical Research Programs under Grant Number W81XWH2110531 © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e1109 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Nana A. Frimpong More articles by this author Sarah K. Holt More articles by this author Daniel Carson More articles by this author Yohali Burrola-Mendez More articles by this author Jenney Lee More articles by this author Erika Wolff More articles by this author John L. Gore More articles by this author Yaw A. Nyame More articles by this author Expand All Advertisement PDF downloadLoading ...

Supplementary Figure S1. qPCR discriminates between mice hemizygous and homozygous for the BLM-Tg.

Medical imaging devices often use automated processing that creates and displays a self-normalized image. When improperly executed, normalization can misrepresent information or result in an inaccurate analysis. In the case of diagnostic imaging, a false positive in the absence of disease, or a negative finding when disease is present, can produce a detrimental experience for the patient and diminish their health prospects and prognosis. In many clinical settings, a medical technical specialist is trained to operate an imaging device without sufficient background information or understanding of the fundamental theory and processes involved in image creation and signal processing. Here, we describe a user-friendly image processing algorithm that mitigates user bias and allows for true signal to be distinguished from background. For proof-of-principle, we used antibody-targeted molecular imaging of colorectal cancer (CRC) in a mouse model, expressing human MUC1 at tumor sites. Lesion detection was performed using targeted magnetic resonance imaging (MRI) of hyperpolarized silicon particles. Resulting images containing high background and artifacts were then subjected to individualized image post-processing and comparative analysis. Post-acquisition image processing allowed for co-registration of the targeted silicon signal with the anatomical proton magnetic resonance (MR) image. This new methodology allows users to calibrate a set of images, acquired with MRI, and reliably locate CRC tumors in the lower gastrointestinal tract of living mice. The method is expected to be generally useful for distinguishing true signal from background for other cancer types, improving the reliability of diagnostic MRI.

Current treatments for xerostomia/dry mouth are palliative and largely ineffective. A permanent clinical resolution is being developed to correct hyposalivation using implanted hydrogel-encapsulated salivary human stem/progenitor cells (hS/PCs) to restore functional salivary components and increase salivary flow. Pluripotent epithelial cell populations derived from hS/PCs, representing a basal stem cell population in tissue, can differentiate along either secretory acinar or fluid-transporting ductal lineages. To develop tissue-engineered salivary gland replacement tissues, it is critical to reliably identify cells in tissue and as they enter these alternative lineages. The secreted protein α-amylase, the transcription factor MIST1, and aquaporin-5 are typical markers for acinar cells, and K19 is the classical ductal marker in salivary tissue. We found that early ductal progenitors derived from hS/PCs do not express K19, and thus earlier markers were needed to distinguish these cells from acinar progenitors. Salivary ductal cells express distinct polarity complex proteins that we hypothesized could serve as lineage biomarkers to distinguish ductal cells from acinar cells in differentiating hS/PC populations. Based on our studies of primary salivary tissue, both parotid and submandibular glands, and differentiating hS/PCs, we conclude that the apical marker MUC1 along with the polarity markers INADL/PATJ and SCRIB reliably can identify ductal cells in salivary glands and in ductal progenitor populations of hS/PCs being used for salivary tissue engineering. Other markers of epithelial maturation, including E-cadherin, ZO-1, and partition complex component PAR3, are present in both ductal and acinar cells, where they can serve as general markers of differentiation but not lineage markers.

Silicon-based micro and nanoparticles are ideally suited for use as biomedical imaging agents because of their biocompatibility, biodegradability, and simple surface chemistry that facilitates drug loading and targeting. A method to hyperpolarize silicon particles using dynamic nuclear polarization (DNP), which increases magnetic resonance (MR) imaging signals by several orders-of-magnitude through enhanced nuclear spin alignment, was developed to allow silicon particles to function as contrast agents for in vivo magnetic resonance imaging. In this review, we describe the application of the DNP technique to silicon particles and nanoparticles for background-free real-time molecular MR imaging. This review provides a summary of the state-of-the-science in silicon particle hyperpolarization with a detailed protocol for hyperpolarizing silicon particles. This information will foster awareness and spur interest in this emerging area of nanoimaging and provide a path to new developments and discoveries to further advance the field. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

“Tumor-educated platelets” have recently generated substantial interest for the diagnosis of cancer. We hypothesized that tumor educated platelets from patients with brain tumors will reflect altered metabolism compared to platelets from healthy volunteers. Here, in a pilot study, we have employed nuclear magnetic resonance (NMR) spectroscopy in platelets from brain tumor patients to demonstrate altered metabolism compared to the platelets obtained from healthy volunteers.

Background Sialyl-Lewis X/L-selectin high affinity binding interactions between transmembrane O-glycosylated mucins proteins and the embryo have been implicated in implantation processes within the human reproductive system. However, the adhesive properties of these mucins at the endometrial cell surface are difficult to resolve due to known discrepancies between in vivo models and the human reproductive system and a lack of sensitivity in current in vitro models. To overcome these limitations, an in vitro model of the human endometrial epithelial was interrogated with single molecule force spectroscopy (SMFS) to delineate the molecular configurations of mucin proteins that mediate the high affinity L-selectin binding required for human embryo implantation. Results This study reveals that MUC1 contributes to both the intrinsic and extrinsic adhesive properties of the HEC-1 cellular surface. High expression of MUC1 on the cell surface led to a significantly increased intrinsic adhesion force (148 pN vs. 271 pN, p < 0.001), whereas this adhesion force was significantly reduced (271 pN vs. 118 pN, p < 0.001) following siRNA mediated MUC1 ablation. Whilst high expression of MUC1 displaying elevated glycosylation led to strong extrinsic (> 400 pN) L-selectin binding at the cell surface, low expression of MUC1 with reduced glycosylation resulted in significantly less (≤200 pN) binding events. Conclusions An optimal level of MUC1 together with highly glycosylated decoration of the protein is critical for high affinity L-selectin binding. This study demonstrates that MUC1 contributes to cellular adhesive properties which may function to facilitate trophoblast binding to the endometrial cell surface through the L-selectin/sialyl-Lewis x adhesion system subsequent to implantation.

Abstract Background: Polarized epithelium is stabilized by lateral cell-cell interactions via cell adhesion molecules (CAMs) and by cell-matrix interactions with basement membrane including with perlecan/HSPG2 (pln). Prostate cancer (PCa) patients with bone metastases have circulating pln fragments, with inverse correlation between MMP-7 staining and loss of pln in cancer tissue. Cleavage of pln by MMP-7 increases cell-matrix interactions and dysregulates cell signaling, permitting migration. We earlier showed pln domain IV-3 (DmIV-3) drives cell-cell cohesion and, when digested with MMP-7, drives cell dyscohesion. Methods: To evaluate the impact of MMP-7 and pln fragments on microtumor dyscohesion and cell migration, uniformly sized PCa microtumors were pre-formed in a microwell system. Pre-formed microtumors were transferred to Dm IV-3 or full length perlecan (FL pln) coated wells for 16-24 hrs. Microtumors were treated with MMP-7 alone or MMP-7 plus predigested Dm IV-3 fragments or MMP-7 plus FL pln fragments. For live cell imaging, tracking of migratory cells leaving microtumors was performed with Imaris software. Co-location of cell adhesion complex components was assessed with Imaris Spots. Results: Pre-formed microtumors cultured with DmIV-3 cleaved by MMP-7 showed lower Pearson's correlation values at cell boundaries compared to microtumors treated with intact Dm IV-3. Line scan analysis revealed E-cadherin and F-actin fluorescent signals were enriched and co-aligned in microtumors treated with Dm IV-3; enrichment and co-alignment were reduced when DmIV-3 fragments and MMP-7 were present. Track number detected per cell cluster was highest in the presence of FL pln fragments plus MMP-7 along with a measurable change in distribution of track displacement lengths of cells toward high values. Conclusion: Boundary reorganization promotes a migratory cell phenotype in microtumors treated with MMP-7 and DmIV-3 fragments. DmIV-3 fragments generated by MMP-7 cleavage can enhance cell dyscohesion by disrupting interactions between CAMs. Ongoing work will identify DmIV-3 fragment(s) positively associated with tumor dyscohesion that play key roles in secondary metastasis formation. Following patterns of dyscohesion of pre-formed microtumors provides a good model to study dynamic changes in intercellular junction components and quantitate cell migration patterns that foster circulating tumor cell formation and metastasis. Citation Format: Lissette A. Cruz, Tristen V. Tellman, Oleg Igoshin, Daniel Carson, Mary (Cindy) Farach-Carson. MMP-7 increases migration by decreasing intercellular cell junction complexes in prostate cancer microtumors formed by perlecan/HSPG2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3120.

INTRODUCTION:Websites and online resources are increasingly becoming patients' main source of healthcare information. It is paramount that high quality information is available online to enhance patient education and improve clinical outcomes. Upper gastrointestinal (UGI) endoscopy is the gold standard investigation for UGI symptoms and yet little is known regarding the quality of patient orientated websites. The aim of this study was to assess the quality of online patient information on UGI endoscopy using the modified Ensuring Quality Information for Patients (EQIP) tool. METHODS:Ten search terms were employed to conduct a systematic review. for each term, the top 100 websites identified via a Google search were assessed using the modified EQIP tool. High scoring websites underwent further analysis. Websites intended for professional use by clinicians as well as those containing video or marketing content were excluded. FINDINGS:A total of 378 websites were eligible for analysis. The median modified EQIP score for UGI endoscopy was 18/36 (interquartile range: 14-21). The median EQIP scores for the content, identification and structure domains were 8/18, 1/6 and 9/12 respectively. Higher modified EQIP scores were obtained for websites produced by government departments and National Health Service hospitals (p=0.007). Complication rates were documented in only a fifth (20.4%) of websites. High scoring websites were significantly more likely to provide balanced information on risks and benefits (94.6% vs 34.4%, p<0.001). CONCLUSIONS:There is an immediate need to improve the quality of online patient information regarding UGI endoscopy. The currently available resources provide minimal information on the risks associated with the procedure, potentially hindering patients' ability to make informed healthcare decisions.

Embryo implantation involves direct interaction of the blastocyst with the lumenal epithelium of the uterus, a highly coordinated and complex process regulated by multiple factors. Mucins, expressed at the apical surface of uterine epithelia, act as a barrier to microbial infection and attack. The transmembrane mucin, MUC1, contributes to the anti-adhesive nature of uterine epithelia influencing uterine function and embryo implantation. Loss of MUC1 is a prerequisite for embryo attachment in most species. This article reviews expression, functions, and regulation of mucins with a particular emphasis on MUC1.

Bone marrow stroma influences metastatic prostate cancer (PCa) progression, latency, and recurrence. At sites of PCa bone metastasis, cancer-associated fibroblasts and tumor-associated macrophages interact to establish a perlecan-rich desmoplastic stroma. As a heparan sulfate proteoglycan, perlecan ( HSPG2 ) stores and stabilizes growth factors, including heparin-binding Wnt3A, a positive regulator of PCa cell growth. Because PCa cells alone do not induce CAF production of perlecan in the desmoplastic stroma, we sought to discover the sources of perlecan and its growth factor-releasing modifiers SULF1, SULF2, and heparanase in PCa cells and xenografts, bone marrow fibroblasts, and macrophages. SULF1, produced primarily by bone marrow fibroblasts, was the main glycosaminoglycanase present, a finding validated with primary tissue specimens of PCa metastases with desmoplastic bone stroma. Expression of both HSPG2 and SULF1 was concentrated in α SMA-rich stroma near PCa tumor nests, where infiltrating pro-tumor TAMs also were present. To decipher SULF1’s role in the reactive bone stroma, we created a bone marrow biomimetic hydrogel incorporating perlecan, PCa cells, macrophages, and fibroblastic bone marrow stromal cells. Finding that M2-like macrophages increased levels of SULF1 and HSPG2 produced by fibroblasts, we examined SULF1 function in Wnt3A-mediated PCa tumoroid growth in tricultures. Comparing control or SULF1 knockout fibroblastic cells, we showed that SULF1 reduces Wnt3A-driven growth, cellularity, and cluster number of PCa cells in our 3D model. We conclude that SULF1 can suppress Wnt3A-driven growth signals in the desmoplastic stroma of PCa bone metastases, and SULF1 loss favors PCa progression, even in the presence of pro-tumorigenic TAMs.

Introduction: Polarized epithelium is maintained by cell-cell interactions via cadherins and cell adhesion molecules (CAMs). Interactions are stabilized further by cell-matrix interactions on the basement membrane where perlecan/HSPG2 is a major component that controls signaling in resting tissues with unperturbed matrices. Proteolytic cleavage of perlecan increases cell-matrix interactions and dysregulates cell signaling, permitting migration. Previous studies showed perlecan domain IV-3 (DmIV-3) drives cell cohesion and, when digested with matrix metalloproteinase-7 (MMP-7), drives cell dyscohesion. In vivo, prostate cancer (PCa) patients with bone metastases have circulating DmIV fragments, with negative correlation between MMP-7 staining and loss of perlecan in tissue samples. MMP-7 can cleave cadherins and other CAMs disrupting cell-cell adhesions. Also, DmIV-3 fragments generated by MMP-7 cleavage may further induce cell dyscohesion by disrupting interactions between CAMs and/or cadherins. Methods: To evaluate the impact of MMP-7 and DmIV-3 fragments on cell migration or cluster dyscohesion, uniformly sized PCa cell clusters were pre-formed using a microwell system, enabling control of cluster size and cellularity. Pre-formed cell clusters were transferred to DmIV-3 coated wells for 16-24 hours. Clusters then were treated with MMP-7 alone or MMP-7 plus DmIV-3 fragments during live cell imaging and cell tracking. Immunofluorescent staining and Imaris analysis of fixed cell clusters at different stages of cohesion and dyscohesion was performed to determine cytoskeletal architecture and stability. The alignment of E-cadherin and F-actin served as a quantitative measure of cohesion. Results: PCa cell clusters maintained strong cell-cell contacts with intact DmIV-3. In contrast, pre-formed PCa cell clusters cultured in the presence of DmIV-3 cleaved by MMP-7 showed dyscohesion and increased cell migration initiated at the cluster edges where migratory velocity was highest. Pre-formed PCa cell clusters treated with MMP-7 had increased F-actin reorganization during various stages of PCa cell cluster dyscohesion. E-cadherin and F-actin co-alignment at cell-cell contacts was reduced in PCa cell clusters treated with MMP-7 and DmIV-3 fragments, particularly at the edges where cell-cell adhesion was lowest and cell-matrix interactions were highest. Conclusion: Following patterns of dyscohesion of pre-formed PCa micro-tumors provides a good model to study dynamic changes in protein components involved in cell-cell interactions and quantitate cell migration patterns as they can occur in metastasis and circulating tumor cell formation. Actin reorganization promotes a migratory cell phenotype in PCa cell clusters treated with MMP-7 and DmIV-3 fragments. Future studies aim to identify DmIV3 fragment(s) positively associated with tumor dyscohesion that may play key roles in secondary metastasis formation. Citation Format: Lissette A. Cruz, Tristen V. Tellman, Brian J. Grindel, Daniel D. Carson, Mary C. Farach-Carson. MMP-7 increases migration by decreasing intercellular E-cadherin and F-actin localization in prostate cancer micro-tumors formed by perlecan/HSPG2 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2608.

Heparan sulfate (HS) is a sulfated glycosaminoglycan that is deposited in human tissue matrices at specialized sites [1,2]. HS interacts with diverse extracellular matrix (ECM) components with HS binding sites, including inflammatory cytokines, and heparinbinding growth factors (HBGFs) [3,4]. Within the ECM and in the cell surface glycocalyx, HS-proteoglycans (HSPGs) act as reservoirs for cytokines and HBGFs, and as cofactors for surface receptors where they stabilize active signaling complexes [5–7]. The bioavailability and activity of HBGFs stored on HSPGs are primarily regulated by HS-modifying enzymes that act on HSPGs, such as perlecan, the syndecans and the glypicans [8,9]. Therefore, HSPGs and their enzymic modifiers are crucial for tissue homeostasis, both in normal biology, as in development and wound healing, and in pathological processes such as fibrosis and cancer biology [1,10,11]. To date, studies have identified three key extracellular enzymes that modulate HS function and growth factor signaling: tissue heparanase (HPSE) and the extracellular endosulfatases SULF1 and SULF2. HPSE is an endoglycosidase that cleaves HS chains yielding diffusible HS fragments [12] that often still retain bound growth factors (Fig. 1A). HS-bound growth factors can subsequently bind to surface receptors to form HS-HBGF-receptor ternary complexes (Fig. 1B) [12]. Like HPSE, SULFs are secreted but, for the most part, stay peripherally associated with the cell surface through the interaction with HSPGs in the glycocalyx, primarily syndecans and glypicans [13,14]. Enzymatic activity of SULFs involves selectively removing 6-O-sulfate groups from HS polymers (Figure 1A) [14,15]. Because many HBGFs require 6-O-sulfate for high-affinity binding to HSPGs or surface coreceptors [3,15,16], SULFs release HBGFs in a form free from HS chains. Freed HBGFs can bind subsequently to cognate cell surface receptors to form signaling complexes, or they may rebind to distant unmodified HSPGs that retain 6-O-sulfate. Therefore, both HPSE and SULFs are crucial enzymes that define activation parameters of HS-independent signaling networks in both positive and negative ways that often are context-dependent [17,18].

Introduction: Polarized epithelium is maintained by cell-cell interactions via cadherins and cell adhesion molecules (CAMs). These interactions are further stabilized by cell-matrix interactions on the basement membrane. Perlecan/HSPG2 is a major component of the basement membrane, controlling signaling in resting tissues with unperturbed matrices. During epithelial to mesenchymal transition in prostate cancer (PCa), cell-cell adhesions decrease and the cells acquire an invasive phenotype. Proteolytic cleavage of perlecan decreases cell-matrix interactions and dysregulates cell signaling, permitting migration. In vivo, patients with bone metastases were found to have circulating DmIV fragments, with a positive correlation between MMP-7 staining and loss of perlecan in tissue samples from these same patients. Recent studies showed perlecan domain IV-3 (DmIV-3) drives cell cohesion and, when digested with matrix metalloproteinase-7 (MMP-7), drives cell dyscohesion. MMP-7 can cleave cadherins and other CAMs disrupting cell-cell adhesions. Additionally, DmIV-3 fragments generated by MMP-7 cleavage may further induce cell dyscohesion by disrupting interactions between CAMs and/or cadherins.Methods: To evaluate the impact of MMP-7 and domain IV-3 fragments, uniformly sized PCa cell clusters were pre-formed using a microwell system, enabling control of cluster size and cell number. These pre-formed cell clusters were transferred to DmIV-3 coated wells for 16-24 hours. Clusters then were treated with MMP-7 alone or MMP-7 plus DmIV-3 fragments and stained for E-cadherin and F-actin.Results: Consistent with previous data, PCa cell clusters maintained strong cell-cell contacts in the presence of DmIV-3. In contrast, we showed that in pre-formed PCa cell clusters cultured in the presence of DmIV-3 cleaved by MMP-7, E-cadherin localization at cell-cell interfaces was reduced. Pre-formed PCa cell clusters treated with MMP-7 had increased F-actin stress fibers present, with a decrease in F-actin organization at cell-cell contacts.Conclusion: Creating PCa micro-tumors using a microwell system provides a good model to study dynamic changes in cell-cell interactions. The purpose of this study was to identify which cell adhesion complexes are perturbed by MMP-7 in these PCa cell clusters. E-cadherin is known to regulate the cortical actin cytoskeleton; thus, decreased E-cadherin at cell-cell contacts results in actin reorganization and an increase in F-actin stress fiber formation, promoting a migratory cell phenotype. Perlecan fragments may augment this behavior by increasing MMP-7 access to the ectodomains of CAMs. This study will be novel in its identification of a DmIV fragment(s) that may provide a prediction marker for PCa metastasis as well as fragments that are positively associated with tumor dyscohesion.Citation Format: Lissette A. Cruz, Tristen V. Tellman, Mary C. Farach-Carson, Brian Grindel, Daniel D. Carson. MMP-7 decreases E-cadherin localization at cell-cell contacts resulting in F-actin cytoskeletal remodeling in prostate cancer micro-tumors formed by perlecan/HSPG2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 67.