Luis E. Lopez

ANTITUMOR ACTIVITY OF HYALURONIC ACID SYNTHESIS INHIBITOR 4-METHYLUMBELLIFERONE IN PROSTATE CANCER CELLS

4-Methylumbelliferone (4-MU) is a hyaluronic acid (HA) synthesis inhibitor with anticancer properties; the mechanism of its anticancer effects is unknown. We evaluated the effects of 4-MU on prostate cancer cells. 4-MU inhibited proliferation, motility, and invasion of DU145, PC3-ML, LNCaP, C4-2B, and/or LAPC-4 cells. At IC(50) for HA synthesis (0.4 mmol/L), 4-MU induced >3-fold apoptosis in prostate cancer cells, which could be prevented by the addition of HA. 4-MU induced caspase-8, caspase-9, and caspase-3 activation, PARP cleavage, upregulation of Fas-L, Fas, FADD and DR4, and downregulation of bcl-2, phosphorylated bad, bcl-XL, phosphorylated Akt, phosphorylated IKB, phosphorylated ErbB2, and phosphorylated epidermal growth factor receptor. At IC(50), 4-MU also caused >90% inhibition of NF-kappaB reporter activity, which was prevented partially by the addition of HA. With the exception of caveolin-1, HA reversed the 4-MU-induced downregulation of HA receptors (CD44 and RHAMM), matrix-degrading enzymes (MMP-2 and MMP-9), interleukin-8, and chemokine receptors (CXCR1, CXCR4, and CXCR7) at the protein and mRNA levels. Expression of myristoylated-Akt rescued 4-MU-induced apoptosis and inhibition of cell growth and interleukin-8, RHAMM, HAS2, CD44, and MMP-9 expression. Oral administration of 4-MU significantly decreased PC3-ML tumor growth (>3-fold) when treatment was started either on the day of tumor cell injection or after the tumors became palpable, without organ toxicity, changes in serum chemistry, or body weight. Tumors from 4-MU-treated animals showed reduced microvessel density ( approximately 3-fold) and HA expression but increased terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells and expression of apoptosis-related molecules. Therefore, the anticancer effects of 4-MU, an orally bioavailable and relatively nontoxic agent, are primarily mediated by inhibition of HA signaling.

Hyaluronic Acid Synthase-1 Expression Regulates Bladder Cancer Growth, Invasion, and Angiogenesis through CD44

Hyaluronic acid (HA) promotes tumor metastasis and is an accurate diagnostic marker for bladder cancer. HA is synthesized by HA synthases HAS1, HAS2, or HAS3. We have previously shown that HAS1 expression in tumor tissues is a predictor of bladder cancer recurrence and treatment failure. In this study, we stably transfected HT1376 bladder cancer cells with HAS1-sense (HAS1-S), HAS1-antisense (HAS1-AS), or vector cDNA constructs. Whereas HAS1-S transfectants produced approximately 1.7-fold more HA than vector transfectants, HA production was reduced by approximately 70% in HAS1-AS transfectants. HAS1-AS transfectants grew 5-fold slower and were approximately 60% less invasive than vector and HAS1-S transfectants. HAS1-AS transfectants were blocked in G(2)-M phase of the cell cycle due to down-regulation of cyclin B1, cdc25c, and cyclin-dependent kinase 1 levels. These transfectants were also 5- to 10-fold more apoptotic due to the activation of the Fas-Fas ligand-mediated extrinsic pathway. HAS1-AS transfectants showed a approximately 4-fold decrease in ErbB2 phosphorylation and down-regulation of CD44 variant isoforms (CD44-v3, CD44-v6, and CD44-E) both at the protein and mRNA levels. However, no decrease in RHAMM levels was observed. The decrease in CD44-v mRNA levels was not due to increased mRNA degradation. Whereas CD44 small interfering RNA (siRNA) transfection decreased cell growth and induced apoptosis in HT1376 cells, HA addition modestly increased CD44 expression and cell growth in HAS1-AS transfectants, which could be blocked by CD44 siRNA. In xenograft studies, HAS1-AS tumors grew 3- to 5-fold slower and had approximately 4-fold lower microvessel density. These results show that HAS1 regulates bladder cancer growth and progression by modulating HA synthesis and HA receptor levels.

Targeting Hyaluronidase for Cancer Therapy: Antitumor Activity of Sulfated Hyaluronic Acid in Prostate Cancer Cells

The tumor cell-derived hyaluronidase (HAase) HYAL-1 degrades hyaluronic acid (HA) into proangiogenic fragments that support tumor progression. Although HYAL-1 is a critical determinant of tumor progression and a marker for cancer diagnosis and metastasis prediction, it has not been evaluated as a target for cancer therapy. Similarly, sulfated hyaluronic acid (sHA) has not been evaluated for biological activity, although it is an HAase inhibitor. In this study, we show that sHA is a potent inhibitor of prostate cancer. sHA blocked the proliferation, motility, and invasion of LNCaP, LNCaP-AI, DU145, and LAPC-4 prostate cancer cells, and induced caspase-8-dependent apoptosis associated with downregulation of Bcl-2 and phospho-Bad. sHA inhibited Akt signaling including androgen receptor (AR) phosphorylation, AR activity, nuclear factor κB (NFκB) activation, and VEGF expression. These effects were traced to a blockade in complex formation between phosphoinositide 3-kinase (PI3K) and HA receptors and to a transcriptional downregulation of HA receptors, CD44, and RHAMM, along with PI3K inhibition. Angiogenic HA fragments or overexpression of myristoylated Akt or HA receptors blunted these effects of sHA, implicating a feedback loop between HA receptors and PI3K/Akt signaling in the mechanism of action. In an animal model, sHA strongly inhibited LNCaP-AI prostate tumor growth without causing weight loss or apparent serum-organ toxicity. Inhibition of tumor growth was accompanied by a significant decrease in tumor angiogenesis and an increase in apoptosis index. Taken together, our findings offer mechanistic insights into the tumor-associated HA-HAase system and a preclinical proof-of-concept of the safety and efficacy of sHA to control prostate cancer growth and progression.

HYAL1-v1, an alternatively spliced variant of HYAL1 hyaluronidase: a negative regulator of bladder cancer.

Tumor cells express HYAL1 hyaluronidase, which degrades hyaluronic acid. HYAL1 expression in bladder cancer cells promotes tumor growth, invasion, and angiogenesis. We previously described five alternatively spliced variants of HYAL1 that encode enzymatically inactive proteins. The HYAL1-v1 variant lacks a 30-amino acid sequence that is present in HYAL1. In this study, we examined whether HYAL1-v1 expression affects bladder cancer growth and invasion by stably transfecting HT1376 bladder cancer cells with a HYAL1-v1 cDNA construct. Although HYAL1-v1 transfectants expressed equivalent levels of enzymatically active HYAL1 protein when compared with vector transfectants, their conditioned medium had 4-fold less hyaluronidase activity due to a noncovalent complex formed between HYAL1 and HYAL1-v1 proteins. HYAL1-v1 transfectants grew 3- to 4-fold slower due to cell cycle arrest in the G(2)-M phase and increased apoptosis. In HYAL1-v1 transfectants, cyclin B1, cdc2/p34, and cdc25c levels were > or =2-fold lower than those in vector transfectants. The increased apoptosis in HYAL1-v1 transfectants was due to the extrinsic pathway involving Fas and Fas-associated death domain up-regulation, caspase-8 activation, and BID cleavage, leading to caspase-9 and caspase-3 activation and poly(ADP-ribose) polymerase cleavage. When implanted in athymic mice, HYAL1-v1-expressing tumors grew 3- to 4-fold slower and tumor weights at day 35 were 3- to 6-fold less than the vector tumors (P < 0.001). Whereas vector tumors were infiltrating and had high mitoses and microvessel density, HYAL1-v1 tumors were necrotic, infiltrated with neutrophils, and showed low mitoses and microvessel density. Therefore, HYAL-v1 expression may negatively regulate bladder tumor growth, infiltration, and angiogenesis.

Epigenetic Regulation of HYAL-1 Hyaluronidase Expression IDENTIFICATION OF HYAL-1 PROMOTER

HYAL-1 (hyaluronoglucosaminidase-1) belongs to the hyaluronidase family of enzymes that degrade hyaluronic acid. HYAL-1 is a marker for cancer diagnosis and a molecular determinant of tumor growth, invasion, and angiogenesis. The regulation of HYAL-1 expression is unknown. Real time reverse transcription-PCR using 11 bladder and prostate cancer cells and 69 bladder tissues showed that HYAL-1 mRNA levels are elevated 10–30-fold in cells/tissues that express high hyaluronidase activity. Although multiple transcription start sites (TSS) for HYAL-1 mRNA were detected in various tissues, the major TSS in many tissues, including bladder and prostate, was at nucleotide 27274 in the cosmid clone LUCA13 (AC002455). By analyzing the 1532 base sequence 5′ to this TSS, using cloning and luciferase reporter assays, we identified a TACAAA sequence at position -31 and the minimal promoter region between nucleotides -93 and -38. Mutational analysis identified that nucleotides -73 to -50 (which include overlapping binding consensus sites for SP1, Egr-1, and AP-2), bases C-71 and C-59, and an NFκB-binding site (at position -15) are necessary for promoter activity. The chromatin immunoprecipitation assay identified that Egr-1, AP-2, and NFκB bind to the promoter in HYAL-1-expressing cells, whereas SP1 binds to the promoter in non-HYAL-1-expressing cells. 5-Aza-2′-deoxycytidine treatment, bisulfite DNA sequencing, and methylation-specific PCR revealed that HYAL-1 expression is regulated by methylation at C-71 and C-59; both Cs are part of the SP1/Egr-1-binding sites. Thus, HYAL-1 expression is epigenetically regulated by the binding of different transcription factors to the methylated and unmethylated HYAL-1 promoter.

Dietary Supplement 4-Methylumbelliferone: An Effective Chemopreventive and Therapeutic Agent for Prostate Cancer

BACKGROUND Prevention and treatment of advanced prostate cancer (PCa) by a nontoxic agent can improve outcome, while maintaining quality of life. 4-methylumbelliferone (4-MU) is a dietary supplement that inhibits hyaluronic acid (HA) synthesis. We evaluated the chemopreventive and therapeutic efficacy and mechanism of action of 4-MU. METHODS TRAMP mice (7-28 per group) were gavaged with 4-MU (450mg/kg/day) in a stage-specific treatment design (8-28, 12-28, 22-28 weeks). Efficacy of 4-MU (200-450mg/kg/day) was also evaluated in the PC3-ML/Luc(+) intracardiac injection and DU145 subcutaneous models. PCa cells and tissues were analyzed for HA and Phosphoinositide 3-kinase (PI-3K)/Akt signaling and apoptosis effectors. HA add-back and myristoylated Akt (mAkt) overexpression studies evaluated the mechanism of action of 4-MU. Data were analyzed with one-way analysis of variance and unpaired t test or Tukeys multiple comparison test. All statistical tests were two-sided. RESULTS While vehicle-treated transgenic adenocarcinoma of the prostate (TRAMP) mice developed prostate tumors and metastases at 28 weeks, both were abrogated in treatment groups, without serum/organ toxicity or weight loss; no tumors developed at one year, even after stopping the treatment at 28 weeks. 4-MU did not alter the transgene or neuroendocrine marker expression but downregulated HA levels. However, 4-MU decreased microvessel density and proliferative index (P < .0001,). 4-MU completely prevented/inhibited skeletal metastasis in the PC3-ML/Luc(+) model and DU145-tumor growth (85-90% inhibition, P = .002). 4-MU also statistically significantly downregulated HA receptors, PI-3K/CD44 complex and activity, Akt signaling, and β-catenin levels/activation, but upregulated GSK-3 function, E-cadherin, and apoptosis effectors (P < .001); HA addition or mAkt overexpression rescued these effects. CONCLUSION 4-MU is an effective nontoxic, oral chemopreventive, and therapeutic agent that targets PCa development, growth, and metastasis by abrogating HA signaling.

External Validation of a Multiplex Urinary Protein Panel for the Detection of Bladder Cancer in a Multicenter Cohort

Background: Because of the faltering sensitivity and/or specificity, urine-based assays currently have a limited role in the management of patients with bladder cancer. The aim of this study was to externally validate our previously reported protein biomarker panel from multiple sites in the United States and Europe. Methods: This multicenter external validation study included a total of 320 subjects (bladder cancer = 183). The 10 biomarkers (IL8, MMP9, MMP10, SERPINA1, VEGFA, ANG, CA9, APOE, SDC1, and SERPINE1) were measured using commercial ELISA assays in an external laboratory. The diagnostic performance of the biomarker panel was assessed using receiver operator curves (ROC) and descriptive statistical values. Results: Utilizing the combination of all 10 biomarkers, the area under the ROC for the diagnostic panel was noted to be 0.847 (95% confidence interval, 0.796–0.899), outperforming any single biomarker. The multiplex assay at optimal cutoff value achieved an overall sensitivity of 0.79, specificity of 0.79, positive prediction value of 0.73, and negative prediction value of 0.84 for bladder cancer classification. Sensitivity values of the diagnostic panel for high-grade bladder cancer, low-grade bladder cancer, muscle invasive bladder cancer, and non-muscle invasive bladder cancer were 0.81, 0.90, 0.95, and 0.77, respectively. Conclusions: Urinary levels of the biomarker panel enabled discrimination of patients with bladder cancer and controls, and the levels of biomarker subsets were associated with advancing tumor grade and stage. Impact: If proven to be reliable, urinary diagnostic biomarker assays can detect bladder cancer in a timely manner such that the patient can expect improvements in overall survival and quality of life. Cancer Epidemiol Biomarkers Prev; 23(9); 1804–12. ©2014 AACR.

Antitumor activity of sulfated hyaluronic acid fragments in pre-clinical models of bladder cancer

Tumor cell-derived hyaluronidase HYAL-1 degrades hyaluronic acid (HA) into angiogenic fragments (AGF: 10-12 disaccharides). AGF support tumor growth and progression. Urine and tissue HAase/HYAL-1 levels are sensitive markers for high-grade bladder cancer (BCa) and its metastasis. In preclinical models of BCa, we evaluated whether o-sulfated AGF (sHA-F) inhibits HAase activity and has antitumor activity. At IC50 for HAase activity inhibition (5-20 μg/ml [0.4-1.7 μM]), sHA-F significantly inhibited proliferation, motility and invasion of HYAL-1 expressing BCa cells (253J-Lung, HT1376, UMUC-3), P<0.001. sHA-F did not affect the growth of HYAL-1 non-expressing BCa (5637, RT4, T24, TCCSUP) and normal urothelial (Urotsa, SV-HUC1) cells. sHA-F treatment induced apoptosis by death receptor pathway. sHA-F downregulated transcript and/or protein levels of HA receptors (CD44, RHAMM), p-AKT, β-catenin, pβ-Catenin(S552), Snail and Twist but increased levels of pβ-Catenin(T41/S45), pGSK-3α/β(S21/S9) and E-cadherin. sHA-F also inhibited CD44/Phosphoinositide 3-kinase (PI-3K) complex formation and PI-3K activity. AGF addition or myristoylated-AKT overexpression attenuated sHA-F effects. Contrarily, HYAL-1 expression sensitized RT4 cells to sHA-F treatment. In the 253J-L and HT1376 xenograft models, sHA-F treatment significantly inhibited tumor growth (P<0.001), plausibly by inhibiting angiogenesis and HA receptor-PI-3K/AKT signaling. This study delineates that sHA-F targets tumor-associated HA-HAase system and could be potentially useful in BCa treatment.

Hyaluronic acid family in bladder cancer: potential prognostic biomarkers and therapeutic targets

Background:Molecular markers of clinical outcome may aid in designing targeted treatments for bladder cancer. However, only a few bladder cancer biomarkers have been examined as therapeutic targets.Methods:Data from The Cancer Genome Atlas (TCGA) and bladder specimens were evaluated to determine the biomarker potential of the hyaluronic acid (HA) family of molecules – HA synthases, HA receptors and hyaluronidase. The therapeutic efficacy of 4-methylumbelliferone (4MU), a HA synthesis inhibitor, was evaluated in vitro and in xenograft models.Results:In clinical specimens and TCGA data sets, HA synthases and hyaluronidase-1 levels significantly predicted metastasis and poor survival. 4-Methylumbelliferone inhibited proliferation and motility/invasion and induced apoptosis in bladder cancer cells. Oral administration of 4MU both prevented and inhibited tumour growth, without dose-related toxicity. Effects of 4MU were mediated through the inhibition of CD44/RHAMM and phosphatidylinositol 3-kinase/AKT axis, and of epithelial–mesenchymal transition determinants. These were attenuated by HA, suggesting that 4MU targets oncogenic HA signalling. In tumour specimens and the TCGA data set, HA family expression correlated positively with β-catenin, Twist and Snail expression, but negatively with E-cadherin expression.Conclusions:This study demonstrates that the HA family can be exploited for developing a biomarker-driven, targeted treatment for bladder cancer, and 4MU, a non-toxic oral HA synthesis inhibitor, is one such candidate.

Abstract 2647: Anti-tumor activity of sHA8k, a HYAL1 hyaluronidase inhibitor, in bladder cancer cells

INTRODUCTION AND OBJECTIVE: Tumor cell-derived hyaluronidase HYAL1, which degrades hyaluronic acid (HA) into angiogenic fragments, promotes tumor growth and metastasis. HYAL-1 is an independent prognostic marker for predicting metastasis. Small molecular mass sulfated hyaluronic acid (sHA) derivatives (sHA8k) inhibit HYAL1 activity through a mixed inhibition mechanism. Antitumor activity of sHA8k and mechanism of action was evaluated in BCa models.. METHODS: Effect of sHA8k (0-40 ug/ml) on cell proliferation and apoptosis was examined in BCa cells (253J-Lung, HT1376, UMUC-3, T24, RT4) by cell counting and Cell Death ELISA kit. Matrigel invasion and Boyden chamber assays were used to test the effect of sHA8k on invasive activity. Effect of sHA on signaling, apoptosis cascade, HA receptor (CD44, RHAMM), EMT markers (β-catenin, E-cadherin, Snail, Twist) levels, was evaluated by Q-pCR and immunoblotting assays. Angiogenic fragment addition and mAkt transfection were performed to elucidate mechanism of action. Athymic mice bearing 253J-Lung xenografts were treated with sHA (25 and 50 mg/kg) by i.p. injection. RESULTS: sHA8k inhibited proliferation, motility and invasion in BCa cells that expressed HYAL-1. At IC50 for HAase activity inhibition (∼ 20-μg/ml), sHA induced > 3-fold apoptosis and inhibited invasive activity of BCa cells. sHA8k induced caspase-3, -8, -9 activation, up-regulation of Fas, Fas-L, FADD, DR4, DR5 and E-cadherin. sHA8k downregulated CD44, RHAMM, bcl-2, phospho(p)-Akt, pGSK3β, pβcatenin(ser552), snail and Twist expression. Effect of sHA8k were attenuated by angiogenic HA fragments or overexpression of m-Akt and downregulation of CD44 and RHAMM mimicked sHA8k effects. sHA significantly inhibited 253J-Lung xenograft growth. The majority of the animals did not form palpable tumors at 50-mg/kg dose. No weight loss or serum and organ toxicity was observed in sHA treated animals. Biochemical analysis of tumors also showed the same alterations in Akt and EMT pathways as observed cell culture. CONCLUSION: This is the first study that shows sHA8k, a small molecular mass HYAL-1 inhibitor has potent antitumor activity. Support: R01 CA 72821-14 (VBL) Citation Format: Andre R. Jordan, Juan Chipollini, Luis Lopez, Travis Yates, Vinata Lokeshwar. Anti-tumor activity of sHA8k, a HYAL1 hyaluronidase inhibitor, in bladder cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2647. doi:10.1158/1538-7445.AM2015-2647