Inhibits Prostate Cancer Cell Migration Research Articles

CircUBE3A(2,3,4,5) promotes adenylate-uridylate-rich binding factor 1 nuclear translocation to suppress prostate cancer metastasis

Metastatic progression is the primary cause of mortality in prostate cancer (PCa) patients. Although circular RNAs (circRNAs) have been implicated in cancer progression and metastasis, our current understanding of their role in PCa metastasis remains limited. In this study, we identified that circUBE3A(2,3,4,5), which originated from exons 2, 3, 4 and 5 of the human ubiquitin-protein ligase E3A (UBE3A) gene, was specifically downregulated in PCa tissues and correlated with the Gleason score, bone metastasis, and D'Amico risk classification. Through the in vitro and in vivo experiments, we demonstrated that overexpression of circUBE3A(2,3,4,5) inhibited PCa cell migration, invasion, metastasis, and proliferation. Mechanistically, circUBE3A(2,3,4,5) was found to bind to adenylate-uridylate-rich binding factor 1 (AUF1), promoting the translocation of AUF1 into the nucleus. This led to decreased AUF1 in the cytoplasm, resulting in methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) mRNA instability and a subsequent reduction at the protein level. The downregulation of MTHFD2 further inhibited vimentin expression, thereby suppressing PCa cell epithelial-mesenchymal transition. Additionally, two pairs of the short-inverted repeats (TSIRs) in flanking introns were identified to synergistically facilitate the generation of circUBE3A(2,3,4,5) and other circRNAs. In summary, TSIRs-induced circUBE3A(2,3,4,5) acts as a suppressor of PCa metastasis by enhancing AUF1 nuclear translocation, reducing MTHFD2, and subsequently inhibiting vimentin expression. This study characterizes circUBE3A(2,3,4,5) as a functional circRNA and proposes it as a highly promising target for preventing PCa metastasis.

A protein-encoding CCDC7 circular RNA inhibits the progression of prostate cancer by up-regulating FLRT3

Circular RNAs (circRNAs) are a family of endogenous RNAs that have become a focus of biological research in recent years. Emerging evidence has revealed that circRNAs exert biological functions by acting as transcriptional regulators, microRNA sponges, and binding partners with RNA-binding proteins. However, few studies have identified coding circRNAs, which may lead to a hidden repertoire of proteins. In this study, we unexpectedly discovered a protein-encoding circular RNA circCCDC7(15,16,17,18,19) while we were searching for prostate cancer related chimeric RNAs. circCCDC7(15,16,17,18,19) is derived from exon 19 back spliced to exon 15 of the CCDC7 gene. It is significantly downregulated in patients with high Gleason score. Prostate cancer patients with decreased circCCDC7(15,16,17,18,19) expression have a worse prognosis, while linear CCDC7 had no such association. Overexpressed circCCDC7(15,16,17,18,19) inhibited prostate cancer cell migration, invasion, and viability, supporting classification of circCCDC7(15,16,17,18,19) as a bona fide tumor suppressor gene. We provide evidence that its tumor suppressive activity is driven by the protein it encodes, and that circCCDC7(15,16,17,18,19) encodes a secretory protein. Consistently, conditioned media from circCCDC7(15,16,17,18,19) overexpressing cells has the same tumor suppressive activity. We further demonstrate that the tumor suppressive activity of circCCDC7(15,16,17,18,19) is at least partially mediated by FLRT3, whose expression also negatively correlates with Gleason score and clinical prognosis. In conclusion, circCCDC7(15,16,17,18,19) functions as a tumor suppressor in prostate cancer cells through the circCCDC7-180aa secretory protein it encodes, and is a promising therapeutic peptide for prostate cancer.

The study of a novel CDK8 inhibitor E966-0530–45418 that inhibits prostate cancer metastasis in vitro and in vivo

Prostate cancer is a prevalent malignancy among men globally, and androgen deprivation therapy is the conventional first-line treatment for metastatic prostate cancer. While androgen deprivation therapy is efficacious in castration-sensitive prostate cancer, it remains less effective in castration-resistant cases. Transcriptional dysregulation is a well-established hallmark of cancer, and targeting proteins involved in transcriptional regulation, such as cyclin-dependent kinase 8 (CDK8), has become an attractive therapeutic strategy. CDK8, a nuclear serine-threonine kinase, is a key component of the mediator complex and plays a critical role in transcriptional regulation. Recent studies have highlighted the promising role of CDK8 as a target in the treatment of metastatic prostate cancer. Our study assessed the efficacy of a novel CDK8 inhibitor, E966–0530–45418, which exhibited potent CDK8 inhibition (IC50 of 129 nM) and high CDK8 selectivity. Treatment with E966–0530–45418 significantly inhibited prostate cancer cell migration and epithelial-to-mesenchymal transition (EMT) at both the RNA and protein levels. Further mechanistic analysis indicated that E966–0530–45418 suppresses prostate cancer metastasis by decreasing CDK8 activity and inhibiting TGF-β1-mediated Smad3/RNA polymerase II linker phosphorylation and Akt/GSK3β/β-catenin signaling. The results in animal model also showed that E966–0530–45418 exhibited anti-metastatic properties in vivo. Our study demonstrated that E966–0530–45418 has great therapeutic potential in the treatment of metastatic prostate cancer.

The Journal of Urology® Home Study Course 2023 Volume 209/210.

The Journal of Urology® Home Study Course 2023 Volume 209/210.

ARPC1A correlates with poor prognosis in prostate cancer and is up-regulated by glutamine metabolism to promote tumor cell migration, invasion and cytoskeletal changes

ObjectiveThis study aimed to identify potential biomarkers for prostate cancer (PCa) progression and metastasis, and to discern their biological functions.MethodsBioinformatics methods were used to screen for hub genes. The expression level of key hub genes in PCa was determined and their prognostic significance was examined. A series of functional assays were performed to investigate the function of the highest-ranking hub gene.ResultsActin related protein 2/3 complex subunit 1A (ARPC1A) was identified as the hub gene. ARPC1A was highly expressed in PCa tissues and cell lines, and was an independent prognostic factor for predicting biochemical recurrence after radical prostatectomy and overall survival of PCa patients. Knockdown of ARPC1A inhibited PCa cell migration, invasion and cytoskeleton formation, but had no impact on cell proliferation and cell cycle progression. In vivo, ARPC1A overexpression promoted lung metastasis of PCa, but had no efffect on tumor growth. Additionally, glutamine metabolism was identified as an upstream regulator of ARPC1A, and promoted migration, invasion and cytoskeletal changes of PCa cell through ARPC1A.ConclusionThese findings suggested that ARPC1A, which correlates with poor prognosis in PCa, functions downstream of glutamine metabolism to regulate cytoskeletal changes, cellular migration and cellular invasion in this disease.

MiR-375 Enriched in Bone Marrow Mesenchymal Stem Cells (BMSC) Exosomes Inhibits Prostate Cancer Cell Migration and Invasion by Down-Regulating Trefoil Factor 3 (TFF3)

To study the effect and mechanism of miR-375 enriched in BMSC exosomes on prostate cancer (PC) cells. Bioinformatics assessed the potential regulatory miRNA of TFF3 and miR-375 level in breast cancer cells and breast cancer clinical samples was detected by PCR. Dual luciferase assay validated the relationship between TFF3 and miR-375. miR-375 mimics or sh-TFF3 was transfected into PC cells, followed by measuring miR-375 and TFF3 by PCR and Western-blot. Cell proliferation, invasion, migration and apoptosis by Edu staining, transwell and flow cytometry. The BMSC exosomes were then isolated and co-cultured with PC cells to detect cell proliferation and invasion. PC cells and tissues showed the expression of miR-375 was decreased, indicated that miR-375 specifically inhibited TFF3 level. miR-375 was enriched in MSC-derived exosomes and could be transferred to PC cells. miR-375 mimics, exosome miR-375 or silenced TFF3 inhibited TFF3 level, up-regulated PCNA, MMP-2/9 expression, thereby inhibiting cell proliferation and metastasis, and promoting cell apoptosis. miR-375 is enriched in BMSC exosomes and inhibits PC cell migration and invasion by reducing TFF3.

Abstract 46: A new class of precision therapeutics that inhibit prostate cancer mediated bone destruction

Abstract The destructive nature of bone metastases dominates the clinical management of advanced prostate cancer (PCa) and is a common cause of morbidity and mortality. Our current ability to therapeutically target this process is limited. Here we describe the synthesis and functional characterization of the first-in-class Dual Acting Bone Defending agents (DABDs), which couple a small molecule therapeutic that inhibits cell movement to bone trophic bisphosphonates. Upfront in-vitro screens assessed DABD efficacy at inhibiting PCa cell migration and invasion and osteoclast mediated bone destruction. Systemic models of PCa metastasis, inclusive of intracardiac (IC) and intratibial (IT) injection models, were deployed to characterize tolerance and efficacy in-vivo. Finally, in-vitro characterization of DABD molecular mechanism of action was performed, as guided by the existing knowledge base related to the parental compounds. Results demonstrated that DABDs inhibit PCa cell migration and invasion, chemically bind hydroxyappetite, and inhibit osteoclast mediated bone destruction in vitro. Following IC injection of PCa cells, a model where cells are placed into circulation, metastasize to bone, grow and induce bone destruction, emulating the clinical scenario in humans, DABD treatment inhibited circulating PCa cells from forming new bone metastasis and prolonged life in a dose-dependent fashion. In the IT mouse models of established metastatic lesions, DABDs induce reversion of PCa cell growth and disrupt further bone destruction. DABDs at doses 1000 fold higher than those associated with efficacy are well tolerated. At the molecular level, DABDs retain the molecular mechanisms of action of their constituent chemicals. They inhibit farnesyl diphosphate synthase (FDPS), in the mevalonate pathway, leading to decreased prenylation of small GTPases, including the Ras related protein, Rap-1A, as well as inhibit Raf1 activation, inducing apoptosis and impaired cell movement, respectively. DABDs are a new class of agents that inhibit formation of new bone metastasis, revert growth of established metastasis, prolong life, and have a high potential for improving clinical outcome in humans. Citation Format: Ryan R. Gordon, Abhinandan Pattanayak, Wenqi Li, Raymond Bergan. A new class of precision therapeutics that inhibit prostate cancer mediated bone destruction [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 46.

EWI-2 controls nucleocytoplasmic shuttling of EGFR signaling molecules and miRNA sorting in exosomes to inhibit prostate cancer cell metastasis.

Early and accurate diagnosis of prostate cancer (PCa) is extremely important, as metastatic PCa remains hard to treat. EWI‐2, a member of the Ig protein subfamily, is known to inhibit PCa cell migration. In this study, we found that EWI‐2 localized on both the cell membrane and exosomes regulates the distribution of miR‐3934‐5p between cells and exosomes. Interestingly, we observed that EWI‐2 is localized not only on the plasma membrane but also on the nuclear envelope (nuclear membrane), where it regulates the nuclear translocation of signaling molecules and miRNA. Collectively, these functions of EWI‐2 found in lipid bilayers appear to regulate PCa cell metastasis through the epidermal growth factor receptor‐mitogen‐activated protein kinase‐extracellular‐signal‐regulated kinase (EGFR‐MAPK‐ERK) pathway. Our research provides new insights into the molecular function of EWI‐2 on PCa metastasis, and highlights EWI‐2 as a potential PCa biomarker.

FGF21 facilitates autophagy in prostate cancer cells by inhibiting the PI3K\u2013Akt\u2013mTOR signaling pathway

Fibroblast growth factor 21 (FGF21) plays an important role in regulating glucose and lipid metabolism, but its role in cancer is less well-studied. We aimed to investigate the action of FGF21 in the development of prostate cancer (PCa). Herein, we found that FGF21 expression was markedly downregulated in PCa tissues and cell lines. FGF21 inhibited the proliferation and clone formation of LNCaP cells (a PCa cell line) and promoted apoptosis. FGF21 also inhibited PCa cell migration and invasiveness. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that FGF21 was related to autophagy and the phosphatidylinositol 3-kinase–Akt kinase–mammalian target of rapamycin (PI3K–Akt–mTOR) pathway. Mechanistically, FGF21 promoted autophagy in LNCaP cells by inhibiting the PI3K–Akt–mTOR–70S6K pathway. In addition, FGF21 inhibited PCa tumorigenesis in vivo in nude mice. Altogether, our findings show that FGF21 inhibits PCa cell proliferation and promoted apoptosis in PCa cells through facilitated autophagy. Therefore, FGF21 might be a potential novel target in PCa therapy.

Identification of Differentially Methylated Regions Associated with a Knockout of SUV39H1 in Prostate Cancer Cells

Epigenetic alterations, such as histone methylations, affect the pathogenesis of tumors including prostate cancer (PCa). Previously, we reported that metformin reduced SUV39H1, a histone methyltransferase of H3 Lys9, to inhibit the migration of PCa cells. Since histone methylation is functionally linked to DNA methylation, we speculate that the knockout of the SUV39H1 gene will affect the genomic DNA methylation profile to regulate PCa cell migration and invasion. The genome-wide DNA methylation level is lower in SUV39H1 knockout (KO) cells than wild-type (WT) ones. However, the methylation levels in functional regions of CpG Islands (CGI), 5′ untranslated region (UTR5), and exon regions are higher in KO cells than WT cells. Analysis of differentially methylated regions (DMRs) identified 1241 DMR genes that have differential methylation on CG sites when comparing the KO and WT samples. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes Pathways analysis showed that knockout of SUV39H1 affects gene sets and pathways that are heavily involved in cell shapes, cell recognition, adhesion, motility, and migration. Our study suggests that SUV39H1 plays an important role in PCa migration via the epigenetic regulation of methylation on CG sites, and is a novel and legitimate target to inhibit PCa cell migration.

Analysis of key genes reveal lysine demethylase 5B promotes prostate cancer progression.

Prostate cancer (PCa) is one of the most common types of cancer in males globally. However, the molecular mechanisms underlying PCa progression remain largely unclear. In the present study, Gene Expression Omnibus (GEO) datasets and datasets from The Cancer Genome Atlas (TCGA) were used to analyze the expression of lysine demethylase 5B (KDM5B) in PCa. Proliferation, cell cycle and migration assays were used to detect the functional roles of KDM5B. It was found KDM5B was upregulated in PCa tissues by analyzing GEO and TCGA datasets. KDM5B knockdown significantly suppressed proliferation and cell cycle progression in PCa cells. In additional, KDM5B knockdown inhibited PCa cell migration. By analyzing a TCGA dataset, KDM5B was found to be upregulated in patients at N1 stage compared with N0 stage PCa, in patients at T3+T4 stages compared with T2 stage and in patients with Gleason score ≥8 compared with those with score ≤7. Kaplan-Meier analysis revealed that higher expression of KDM5B was associated with shorter biochemical recurrence-free survival and overall survival time in patients with PCa. These results suggest that expression of KDM5B may serve as a biomarker to predict the outcome of PCa.

MicroRNA‑137 regulates hypoxia‑mediated migration and epithelial‑mesenchymal transition in prostate cancer by targeting LGR4 via the EGFR/ERK signaling pathway.

MicroRNAs (miRs) serve an integral role in prostate cancer. The present study aimed to investigate the effects and mechanisms of miR‑137 in hypoxia‑mediated migration and epithelial‑mesenchymal transition (EMT). PC3 and DU145 prostate cancer cells were exposed to hypoxia for 24h, after which the expression of miR‑137 was determined by reverse transcription‑quantitative PCR (RT‑qPCR). The cells were transfected with a miR‑137 mimic or inhibitor, followed by hypoxia exposure. The results demonstrated that hypoxia reduced miR‑137 expression. Further results from the Cell Counting Kit‑8, Cell Death Detection ELISA plus kit, Transwell assay, RT‑qPCR and western blotting assays revealed that the miR‑137 mimic prevented cell proliferation, facilitated apoptosis and repressed cell migration, invasiveness, and expression of N‑cadherin, vimentin and matrix metalloproteinase 2; the miR‑137 inhibitor exerted the opposite effects. A dual‑-luciferase reporter assay determined that miR‑137 directly targeted leucine‑rich repeat‑containing G protein‑coupled receptor4 (LGR4). Additionally, miR‑137 negatively regulated the epidermal growth factor receptor/extracellular signal‑-regulated kinase (EGFR/ERK) signaling pathway by targeting LGR4. LGR4 silencing or EGFR/ERK inhibition abolished the effects of miR‑137 inhibitor on cell migration and EMT. In conclusion, by targeting LGR4 via the EGFR/ERK signaling pathway, miR‑137 inhibited prostate cancer cell migration and EMT.

Structure-activity relationships of triazole-benzodioxine inhibitors of cathepsin X

Cathepsin X is a cysteine carboxypeptidase that is involved in various physiological and pathological processes. In particular, highly elevated expression and activity of cathepsin X has been observed in cancers and neurodegenerative diseases. Previously, we identified compound Z9 (1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-((4-isopropyl-4H-1,2,4-triazol-3-yl)thio)ethan-1-one) as a potent and specific reversible cathepsin X inhibitor. Here, we have explored the effects of chemical variations to Z9 of either benzodioxine or triazol moieties, and the importance of the central ketomethylenethio linker. The ketomethylenethio linker was crucial for cathepsin X inhibition, whereas changes of the triazole heterocycle did not alter the inhibitory potencies to a greater extent. Replacement of benzodioxine moiety with substituted benzenes reduced cathepsin X inhibition. Overall, several synthesized compounds showed similar or improved inhibitory potencies against cathepsin X compared to Z9, with IC50 values of 7.1 μM–13.6 μM. Additionally, 25 inhibited prostate cancer cell migration by 21%, which is under the control of cathepsin X.

Tumor suppressor RKIP inhibits prostate cancer cell metastasis and sensitizes prostate cancer cells to docetaxel treatment.

Raf kinase inhibitory protein (RKIP) is a well-established metastasis suppressor that is frequently down-regulated in aggressive cancers. However, the impact of RKIP on cancer cell invasion and metastasis in prostate cancer is still elusive. To this end, we overexpressed RKIP in two prostate cancer cell lines. We found that overexpression of RKIP inhibited prostate cancer cells proliferation, migration and invasion. Mechanistically, we found that RKIP overexpression led to down-regula- tion of the NF-kB signaling pathway and inhibition of the epithelial-to-mesenchymal transition, which is important step for cancer metastasis. In addition, overexpression of RKIP can promote drug effects of docetaxel on prostate cancer cell lines. In conclusion, overexpression of RKIP significantly inhibits prostate cancer cell migration and metastasis, and overexpression of RKIP could aid prostate cancer treatment and therapy.

Ganoderma lucidum polysaccharide inhibits prostate cancer cell migration via the protein arginine methyltransferase 6 signaling pathway.

Prostate cancer is one of the most common types of malignant tumor of men worldwide and the incidence and mortality rate is gradually increasing. At present, the molecular mechanisms of growth and migration in human prostate cancer have not been completely elucidated. Studies have demonstrated that Ganoderma lucidum polysaccharides (GLP) can inhibit cancer. Therefore the present study investigated the effect and molecular mechanism of GLP on cell growth and migration of LNCaP human prostate cancer cells. LNCaP cells were transfected with either a protein arginine methyltransferase 6 (PRMT6) overexpression plasmid or PRMT6 small interfering (si)RNA. The cell growth and migration, and the expression of PRMT6 signaling-associated proteins, were investigated following treatment with 5 and 20 µg/ml GLP. The results demonstrated that GLP inhibited cell growth, induced cell cycle arrest, decreased PRMT6, cyclin-dependent kinase 2 (CDK2), focal adhesion kinase (FAK) and steroid receptor coactivator, (SRC) expression, and increased p21 expression in LNCaP cells, as determined by using a Coulter counter, flow cytometry, and reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. Furthermore, GLP significantly inhibited cell migration, as determined by Transwell migration and scratch assays, and altered CDK2, FAK, SRC and p21 expression in LNCaP cells transfected with the PRMT6 overexpression plasmid. By contrast, PRMT6 knockdown by siRNA reduced the effect of GLP on cell migration. These results indicate that GLP was effective in inhibiting cell growth, the cell cycle and cell migration, and the suppressive effect of GLP on cell migration may occur via the PRMT6 signaling pathway. Therefore, it is suggested that GLP may act as a tumor suppressor with applications in the treatment of prostate cancer. The results of the present study provide both the preliminary theoretical and experimental basis for the investigation of GLP as a therapeutic agent.

Ligand-dependent EphA7 signaling inhibits prostate tumor growth and progression

The downregulation of receptor tyrosine kinase EphA7 is frequent in epithelial cancers and linked to tumor progression. However, the detailed mechanism of EphA7-mediated prostate tumor progression remains elusive. To test the role of EphA7 receptor in prostate cancer (PCa) progression directly, we generated EphA7 receptor variants that were either lacking the cytoplasmic domain or carrying a point mutation that inhibits its phosphorylation by site-directed mutagenesis. Overexpression of wild-type (WT) EphA7 in PCa cells resulted in decreased tumor volume and increased tumor apoptosis in primary tumors. In addition, ectopic expression of WT EphA7 both can delay PCa cell proliferation and could inhibit PCa cell migration and invasion. This protein can also induce PCa cell apoptosis that correlated with increasing the protein expression levels of Bax, elevating the caspase-3 activities, reducing the protein expression levels of Bcl-2 and facilitating the dephosphorylation of Akt, which is further increased by the stimulation of ephrinA5-Fc. However, expression of these EphA7 mutants in PCa cells has no effect in vivo and in vitro. The expression of EphA7 and ephrinA5 was significantly decreased in PCa specimens compared with BPH tissues or paired normal tissues. Moreover, the phosphorylation of EphA7 was positively related with ephrinA5 expression in human prostate tissues. In sum, receptor phosphorylation of EphA7, at least in part, suppress PCa tumor malignancy through targeting PI3K/Akt signaling pathways.

Vinculin and filamin-C are two potential prognostic biomarkers and therapeutic targets for prostate cancer cell migration.

Prostate cancer (PCa) is one of the most common diseases for male population, and the effective treatment for metastatic castration-resistant PCa is still lacking. To unravel the underlying mechanism of PCa cell migration, we plan to analyze the related crucial proteins and their roles. In our study, we firstly identify the differentially expressed proteins using quantitative proteomics, and confirm their mRNA expression using quantitative polymerase chain reaction (qPCR). The alterations of these proteins at DNA and mRNA levels are obtained from cBioPortal database. Furthermore, the functions of these proteins are evaluated using wound-healing assay. The quantitative proteomics identified vinculin (VCL) and filamin-C (FLNC) as two highly expressed proteins in PC3 cells, and the DNA and mRNA of these two proteins were amplified and upregulated in a part of PCa patients. Knockdown of VCL and FLNC gene expression significantly inhibit PCa cell migration. These findings suggest that VCL and FLNC identified by quantitative proteomics are highly expressed in PCa cells with high migration potential, and they could be effective targets for repressing PCa cell migration, paving a new avenue for the prognosis and treatment of advanced PCa.

Metformin inhibits SUV39H1-mediated migration of prostate cancer cells

Prostate cancer (PCa) is a leading cause of cancer-related death among men, largely due to incurable distant metastases. Metformin, the most common used anti-type-2 diabetes medicine, has been linked to reduced cancer risk and better diagnosis. We found that metformin was able to inhibit PCa cell migration, which correlates with tumor metastatic capability. The pathogenesis and progression of tumors are closely related to dysregulated gene expression in tumor cells through epigenetic alterations such as DNA methylation and histone modifications. We found that the level of SUV39H1, a histone methyltransferase of H3 Lys9, was reduced in metformin-treated PCa cells in a time-dependent manner. SUV39H1 overexpression increased PCa migration, whereas SUV39H1 depletion suppressed PCa cell migration. There is a positive correlation between SUV39H1 expression and PCa pathological stages. We further showed that both metformin treatment and SUV39H1 knockout in PCa cells can reduce integrin αV and β1 proteins, as well as their downstream phosphorylated focal adhesion kinase (FAK) levels, which is essential for functional adhesion signaling and tumor cell migration. Taken together, metformin reduced SUV39H1 to inhibit migration of PCa cells via disturbing the integrin-FAK signaling. Our study suggests SUV39H1 as a novel target to inhibit PCa cell migration.

PD33-03 PHARMACOLOGIC TARGETING OF TGF-β MEDIATED EMT IN PROSTATE CANCER

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology I1 Apr 2017PD33-03 PHARMACOLOGIC TARGETING OF TGF-β MEDIATED EMT IN PROSTATE CANCER Zheng Cao, Shahriar Koochekpour, Stephen Strup, and Natasha Kyprianou Zheng CaoZheng Cao More articles by this author , Shahriar KoochekpourShahriar Koochekpour More articles by this author , Stephen StrupStephen Strup More articles by this author , and Natasha KyprianouNatasha Kyprianou More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.3317AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Dysregulation of transforming growth factor-β (TGF-β) and insulin-like growth factor (IGF) axis has been linked to reactive stroma dynamics in tumor microenvironment during prostate cancer progression. IGFBP3 induction is initiated by stroma remodeling and could represent a potential therapeutic target for prostate cancer treatment. A lead quinazoline-based Doxazosin® derivative, DZ-50, generated in our laboratory, inhibits prostate tumor growth and vascularity via inducing anoikis and disrupting focal adhesions. Molecular profiling revealed that process of epithelial-mesenchymal-transition (EMT) is also targeted by DZ-50. In this study, we investigated the effect of DZ-50 on EMT landscape, EMT to mesenchymal-epithelial-transition (MET) conversion, and migratory ability of prostate cancer cells within prostate tumor microenvironment. METHODS Human prostate cancer cells LNCaP, LNCaP overexpressing TGF-β type II receptor (TβRII), and cancer associated fibroblasts (CAFs) derived from human prostate cancer specimens, were used. Antitumor effect of DZ-50 against prostate cancer epithelial cells and CAFs was evaluated using cell viability assays. Effect of the drug on EMT key regulators (including IGFBP3) was determined using RT-PCR and Western blot analysis. Drug-induced phenotypic conversions of EMT were evaluated by confocal microscopy. Impact of TGF-β from the stroma microenvironment or exogenous addition of the cytokine, on migration of prostate tumor cells, was assessed using Matrigel assays. RESULTS DZ-50 induced cell death in prostate cancer epithelial cells and CAFs, in a concentration-dependent manner. DZ-50 downregulated IGFBP3 mRNA and protein expression and contributed to MET in LNCaP cells. DZ-50 decreased nuclear IGFBP3 expression with no effect on total protein and promoted MET in LNCaPTβRII cells. In addition, TGF-β reversed DZ-50-induced MET by upregulating IGFBP3 expression in LNCaPTβRII cells. Co-cultures of LNCaPTβRII with CAFs promoted prostate cancer cell migration via TGF-β, an effect that was inhibited by DZ-50. CONCLUSIONS Our results demonstrate that DZ-50 inhibits prostate cancer cell migration and invasion. DZ-50 caused reversal of EMT to MET by regulating IGFBP3 and potentially targeting the prostate stroma in tumor microenvironment. This evidence integrates new signaling mechanisms underlying the antitumor effect of DZ-50 and calls for pre-clinical studies to establish the therapeutic value of this compound in advanced metastatic prostate cancer. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e594 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Zheng Cao More articles by this author Shahriar Koochekpour More articles by this author Stephen Strup More articles by this author Natasha Kyprianou More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

CK2 abrogates the inhibitory effects of PRH/HHEX on prostate cancer cell migration and invasion and acts through PRH to control cell proliferation

PRH/HHEX (proline-rich homeodomain protein/haematopoietically expressed homeobox protein) is a transcription factor that controls cell proliferation, cell differentiation and cell migration. Our previous work has shown that in haematopoietic cells, Protein Kinase CK2-dependent phosphorylation of PRH results in the inhibition of PRH DNA-binding activity, increased cleavage of PRH by the proteasome and the misregulation of PRH target genes. Here we show that PRH and hyper-phosphorylated PRH are present in normal prostate epithelial cells, and that hyper-phosphorylated PRH levels are elevated in benign prostatic hyperplasia, prostatic adenocarcinoma, and prostate cancer cell lines. A reduction in PRH protein levels increases the motility of normal prostate epithelial cells and conversely, PRH over-expression inhibits prostate cancer cell migration and blocks the ability of these cells to invade an extracellular matrix. We show that CK2 over-expression blocks the repression of prostate cancer cell migration and invasion by PRH. In addition, we show that PRH knockdown in normal immortalised prostate cells results in an increase in the population of cells capable of colony formation in Matrigel, as well as increased cell invasion and decreased E-cadherin expression. Inhibition of CK2 reduces PRH phosphorylation and reduces prostate cell proliferation but the effects of CK2 inhibition on cell proliferation are abrogated in PRH knockdown cells. These data suggest that the increased phosphorylation of PRH in prostate cancer cells increases both cell proliferation and tumour cell migration/invasion.