Vinata B. Lokeshwar

Stromal and Epithelial Expression of Tumor Markers Hyaluronic Acid and HYAL1 Hyaluronidase in Prostate Cancer

Hyaluronic acid (HA), a glycosaminoglycan, regulates cell adhesion and migration. Hyaluronidase (HAase), an endoglycosidase, degrades HA into small angiogenic fragments. Using an enzyme-linked immunosorbent assay-like assay, we found increased HA levels (3–8-fold) in prostate cancer (CaP) tissues when compared with normal (NAP) and benign (BPH) tissues. The majority (∼75–80%) of HA in prostate tissues was found to exist in the free form. Primary CaP fibroblast and epithelial cells secreted 3–8-fold more HA than respective NAP and BPH cultures. Only CaP epithelial cells and established CaP lines secreted HAase and the secretion increased with tumor grade and metastasis. The pH activity profile and optimum (4.2; range 4.0–4.3) of CaP HAase was identical to the HYAL1-type HAase present in human serum and urine. Full-length HYAL1 transcript and splice variants were detected in CaP cells by reverse transcriptase-polymerase chain reaction, cloning, and sequencing. Immunoblotting confirmed secretion of a ∼60-kDa HYAL1-related protein by CaP cells. Immunohistochemistry showed minimal HA and HYAL1 staining in NAP and BPH tissues. However, a stromal and epithelial pattern of HA and HYAL1 expression was observed in CaP tissues. While high HA staining was observed in tumor-associated stroma, HYAL1 staining in tumor cells increased with tumor grade and metastasis. The gel-filtration column profiles of HA species in NAP, BPH, and CaP tissues were different. While the higher molecular mass and intermediate size HA was found in all tissues, the HA fragments were found only in CaP tissues. In particular, the high-grade CaP tissues, which showed both elevated HA and HYAL1 levels, contained angiogenic HA fragments. The stromal-epithelial HA and HYAL1 expression may promote angiogenesis in CaP and may serve as prognostic markers for CaP.

CURRENT BLADDER TUMOR TESTS: DOES THEIR PROJECTED UTILITY FULFILL CLINICAL NECESSITY?

PURPOSE We reviewed currently available bladder cancer tests in the context of the clinical expectations of a noninvasive bladder cancer test. MATERIALS AND METHODS We reviewed the literature on bladder cancer tests that are commercially available or have shown clinical usefulness and examined how each test compares with standard methods of bladder cancer diagnosis. RESULTS The clinical necessity for a noninvasive test for bladder cancer is 2-fold, including the early detection of high grade bladder tumors before muscle invasion and monitoring tumor recurrence or new onset. An ideal noninvasive test should be sensitive, specific, rapid, technically simple and have low intra-assay and interassay variability. Urine cytology has high specificity but limited applicability due to its relatively low sensitivity and subjective nature. Hematuria detection by Hemastix dipstick is sensitive but not specific for detecting bladder cancer. Molecules associated with bladder tumor growth and progression may serve as a basis for designing noninvasive diagnostic tests. The Food and Drug Administration approved BTA Stat and BTA TRAK tests, which detect human complement factor H and a related protein in urine, have 60% to 80% sensitivity and 50% to 70% specificity (lower in symptomatic patients) for bladder cancer. The Food and Drug Administration approved NMP22 test, which measures the level of nuclear mitotic apparatus protein in urine, has 50% to 100% sensitivity and 60% to 90% specificity. Accu-Dx detects fibrin degradation products, fibrin and fibrinogen in urine, although this test is no longer commercially available. The Immunocyt test combines cytology with an immunofluorescence technique to improve the sensitivity of cytology for detecting low grade tumors. The telomeric repeat amplification protocol assay for telomerase in exfoliated cells has 70% to 86% sensitivity and 60% to 90% specificity for bladder cancer. However, the low stability of telomerase in urine affects its sensitivity. The hyaluronic acid and hyaluronidase (HA-HAase) test, which measures the urinary level of hyaluronic acid and hyaluronidase, has 90% to 92% sensitivity and 80% to 84% specificity for bladder cancer. Quanticyt karyometry evaluates nuclear shape and DNA content of exfoliated cells to detect bladder cancer. The list of bladder tumor markers is growing rapidly and large multicenter trials are essential to assess their usefulness. CONCLUSIONS Although currently noninvasive bladder cancer tests cannot replace cystoscopy, some have shown a promise of being clinically useful. One or a combination of these tests-markers may prove to be a prostate specific antigen for bladder cancer provided that patients and, more importantly, clinicians accept it.

Interleukin-8 is a molecular determinant of androgen independence and progression in prostate cancer.

The proinflammatory chemokine interleukin-8 (IL-8) is undetectable in androgen-responsive prostate cancer cells (e.g., LNCaP and LAPC-4), but it is highly expressed in androgen-independent metastatic cells, such as PC-3. In this report, we show IL-8 functions in androgen independence, chemoresistance, tumor growth, and angiogenesis. We stably transfected LNCaP and LAPC-4 cells with IL-8 cDNA and selected IL-8-secreting (IL8-S) transfectants. The IL8-S transfectants that secreted IL-8 at levels similar to that secreted by PC-3 cells (100-170 ng/10(6) cells) were characterized. Continuous or transient exposure of LNCaP and LAPC-4 cells to IL-8 reduced their dependence on androgen for growth and decreased sensitivity (>3.5x) to an antiandrogen. IL-8-induced cell proliferation was mediated through CXCR1 and was independent of androgen receptor (AR). Quantitative PCR, immunoblotting, and transfection studies showed that IL8-S cells or IL-8-treated LAPC-4 cells exhibit a 2- to 3-fold reduction in PSA and AR levels, when compared with vector transfectants. IL8-S cells expressed 2- to 3-fold higher levels of phospho-EGFR, src, Akt, and nuclear factor kappaB (NF-kappaB) and showed increased survival when treated with docetaxel. This increase was blocked by NF-kappaB and src inhibitors, but not by an Akt inhibitor. IL8-S transfectants displayed a 3- to 5-fold increased motility, invasion, matrix metalloproteinase-9 and vascular endothelial growth factor production. LNCaP IL8-S cells grew rapidly as tumors, with increased microvessel density and abnormal tumor vasculature when compared with the tumors derived from their vector-transfected counterparts. Therefore, IL-8 is a molecular determinant of androgen-independent prostate cancer growth and progression.

URINARY HYALURONIC ACID AND HYALURONIDASE: MARKERS FOR BLADDER CANCER DETECTION AND EVALUATION OF GRADE

PURPOSE Specific patterns of progression and frequent recurrence of bladder tumors determine the choice of treatment, frequency of surveillance, quality of life, and ultimately, patient prognosis. The prognosis would be improved if an accurate noninvasive test was available for diagnosis. Identification of markers that function in bladder cancer progression would be helpful in designing such diagnostic tests. The glycosaminoglycan, hyaluronic acid (HA), promotes tumor metastasis. Hyaluronidase (HAase), an endoglycosidase, degrades HA into small fragments that promote angiogenesis. We have previously shown that both HA and HAase are associated with bladder cancer and may function in bladder tumor angiogenesis. In this study we examined whether urinary HA and HAase levels serve as bladder cancer markers. MATERIALS AND METHODS Among the 513 urine specimens analyzed, 261 were from transitional cell carcinoma (TCC) patients, 9 from patients with non-TCC tumors, and 243 from controls (normals, patients with other genitourinary (GU) conditions or a history of bladder cancer (HxBCa)). The urinary HA and HAase levels were measured by two ELISA-like assays that utilize a biotinylated HA binding protein for detection. These levels were normalized to total urinary protein and were expressed as ng./mg. (HA test) and mU/mg. (HAase test), respectively. RESULTS The urinary HA levels were elevated (2.5 to 6.5 fold) in bladder cancer patients (1173.7+/-173.4; n = 261) as compared with normals (246.1+/-38.5; n = 41); GU patients (306.6+/-32.2; n = 133), and patients with a HxBCa (351.1+/-49.1; n = 69) (p <0.001). The urinary HAase levels were elevated (3 to 7 fold) in G2/G3 bladder cancer patients (26.2+/-3.2) as compared with normals (4.5+/-0.9) and patients with either GU conditions (5.8+/-1.3), HxBCa (8.2+/-2.6) or G1 tumors (9.7+/-2.5) (p <0.001). The HA test showed 83.1% sensitivity, 90.1% specificity and 86.5% accuracy in detecting bladder cancer, regardless of the tumor grade. The HAase test showed 81.5% sensitivity, 83.8% specificity and 82.9% accuracy to detect G2/G3 patients. Combining the inferences of the HA and HAase tests (HA-HAase test) resulted in detection of bladder cancer, regardless of tumor grade and stage, with higher sensitivity (91.2%) and accuracy (88.3%), and comparable specificity (84.4%). CONCLUSION Our results show that the HA-HAase urine test is a noninvasive, highly sensitive and specific method for detecting bladder cancer and evaluating its grade.

HYAL1 Hyaluronidase in Prostate Cancer: A Tumor Promoter and Suppressor

Hyaluronidases degrade hyaluronic acid, which promotes metastasis. HYAL1 type hyaluronidase is an independent prognostic indicator of prostate cancer progression and a biomarker for bladder cancer. However, it is controversial whether hyaluronidase (e.g., HYAL1) functions as a tumor promoter or as a suppressor. We stably transfected prostate cancer cells, DU145 and PC-3 ML, with HYAL1-sense (HYAL1-S), HYAL1-antisense (HYAL1-AS), or vector DNA. HYAL1-AS transfectants were not generated for PC-3 ML because it expresses little HYAL1. HYAL1-S transfectants produced < or = 42 milliunits (moderate overproducers) or > or = 80 milliunits hyaluronidase activity (high producers). HYAL1-AS transfectants produced <10% hyaluronidase activity when compared with vector transfectants (18-24 milliunits). Both blocking HYAL1 expression and high HYAL1 production resulted in a 4- to 5-fold decrease in prostate cancer cell proliferation. HYAL1-AS transfectants had a G2-M block due to decreased cyclin B1, cdc25c, and cdc2/p34 expression and cdc2/p34 kinase activity. High HYAL1 producers had a 3-fold increase in apoptotic activity and mitochondrial depolarization when compared with vector transfectants and expressed activated proapoptotic protein WOX1. Blocking HYAL1 expression inhibited tumor growth by 4- to 7-fold, whereas high HYAL1 producing transfectants either did not form tumors (DU145) or grew 3.5-fold slower (PC-3 ML). Whereas vector and moderate HYAL1 producers generated muscle and blood vessel infiltrating tumors, HYAL1-AS tumors were benign and contained smaller capillaries. Specimens of high HYAL1 producers were 99% free of tumor cells. This study shows that, depending on the concentration, HYAL1 functions as a tumor promoter and as a suppressor and provides a basis for anti-hyaluronidase and high-hyaluronidase treatments for cancer.

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.

HYAL1 Hyaluronidase: A Molecular Determinant of Bladder Tumor Growth and Invasion

Hyaluronic acid and HYAL1-type hyaluronidase show high accuracy in detecting bladder cancer and evaluating its grade, respectively. Hyaluronic acid promotes tumor progression; however, the functions of hyaluronidase in cancer are largely unknown. In this study, we stably transfected HT1376 bladder cancer cells with HYAL1-sense (HYAL1-S), HYAL1-antisense (HYAL1-AS), or vector cDNA constructs. Whereas HYAL1-S transfectants produced 3-fold more HYAL1 than vector transfectants, HYAL1-AS transfectants showed approximately 90% reduction in HYAL1 production. HYAL1-AS transfectants grew four times slower than vector and HYAL1-S transfectants and were blocked in the G2-M phase of the cell cycle. The expression of cdc25c and cyclin B1 and cdc2/p34-associated H1 histone kinase activity also decreased in HYAL1-AS transfectants. HYAL1-S transfectants were 30% to 44% more invasive, and HYAL1-AS transfectants were approximately 50% less invasive than the vector transfectants in vitro. In xenografts, there was a 4- to 5-fold delay in the generation of palpable HYAL1-AS tumors, and the weight of HYAL1-AS tumors was 9- to 17-fold less than vector and HYAL1-S tumors, respectively (P < 0.001). Whereas HYAL1-S and vector tumors infiltrated skeletal muscle and blood vessels, HYAL1-AS tumors resembled benign neoplasia. HYAL1-S and vector tumors expressed significantly higher amounts of HYAL1 (in tumor cells) and hyaluronic acid (in tumor-associated stroma) than HYAL1-AS tumors. Microvessel density in HYAL1-S tumors was 3.8- and 9.5-fold higher than that in vector and HYAL1-AS tumors, respectively. These results show that HYAL1 expression in bladder cancer cells regulates tumor growth and progression and therefore serves as a marker for high-grade bladder cancer.

Comparison of the prognostic potential of hyaluronic acid, hyaluronidase (HYAL‐1), CD44v6 and microvessel density for prostate cancer

Despite the development of nomograms designed to evaluate a prostate cancer (PCa) patients prognosis, the information has been limited to PSA, clinical stage, Gleason score and tumor volume estimates. We compared the prognostic potential of 4 histologic markers, hyaluronic acid (HA), HYAL‐1‐type hyaluronidase (HAase), CD44v6 and microvessel density (MVD) using immunohistochemistry. HA is a glycosaminoglycan that promotes tumor metastasis. CD44 glycoproteins serve as cell surface receptors for HA, and the CD44v6 isoform is associated with tumor metastasis. HYAL‐1‐type HAase is expressed in tumor cells and, like other HAases, degrades HA into angiogenic fragments. Archival PCa specimens (n = 66) were obtained from patients who underwent radical prostatectomy for clinically localized PCa and had a minimum follow‐up of 72 months (range 72–131 months, mean 103 months). For HA, HYAL‐1 and CD44v6 staining and MVD determination, a biotinylated HA‐binding protein, an anti‐HYAL‐1 IgG, an anti‐CD44v6 IgG and an anti‐CD34 IgG were used, respectively. HA and HYAL‐1 staining was classified as either low‐ or high‐grade. CD44v6 staining and MVD were evaluated quantitatively and then grouped as either low‐ or high‐grade. Using 72 months as the cut‐off limit for evaluating biochemical recurrence, HA, HYAL‐1, combined HA–HYAL‐1, CD44v6 and MVD staining predicted progression with 96%, 84%, 84%, 68% and 76% sensitivity, respectively. Specificity was, 61% (HA), 80.5% (HYAL‐1), 87.8% (HA–HYAL‐1), 56.1% (CD44v6) and 61% (MVD). Sensitivity and specificity values for each marker did not change significantly in a subset of 45 patients for whom follow‐up of longer than 112 months was available. In univariate analysis using the Cox proportional hazards model, preoperative PSA, Gleason sum, margin status, seminal vesicle, extraprostatic extension (EPE), HA, HYAL‐1, HA–HYAL‐1 and MVD, but not CD44v6, age and clinical stage, were significant in predicting biochemical recurrence (p < 0.05). In multivariate analysis using stepwise selection, only preoperative PSA (hazard ratio/unit PSA change = 1.086, p < 0.0001), EPE (hazard ratio = 6.22, p = 0.0016) and HYAL‐1 (hazard ratio = 8.196, p = 0.0009)/HA–HYAL‐1 (hazard ratio = 5.191, p = 0.0021) were independent predictors of biochemical recurrence. HA was an independent predictor of prognosis if HYAL‐1 staining inference was not included in the multivariate model. In our retrospective study with 72‐ to 131‐month follow‐up, EPE, preoperative PSA and HYAL‐1 either alone or together with HA (i.e., combined HA–HYAL‐1) were independent prognostic indicators for PCa.

Elevated tissue expression of hyaluronic acid and hyaluronidase validates the HA-HAase urine test for bladder cancer.

PURPOSE We examined the expression of 2 bladder tumor markers, hyaluronic acid (HA) and hyaluronidase (HAase), in bladder tissues and correlated tissue staining with the inferences of the HA-HAase urine test, which detects bladder cancer. MATERIALS AND METHODS A biotinylated HA binding protein and an antiHYAL1 antibody were used to localize HA and HYAL1 type HAase, respectively, in 83 bladder tissues. Immunoblot analysis was performed using an antiHYAL1 antibody to detect HYAL1. RESULTS A total of 12 normal bladder tissues showed no (66%) to 1+ (34%) HA staining and 0 (83%) to 1+ (17%) HYAL1 staining. The staining intensity of HA and HYAL1 increased in 71 bladder tumor specimens on chi-square analysis (p <0.001). Grade 1 tumors demonstrated 1+ (50%) to 2+ (50%) staining for HA and 1+ to 3+ staining for HYAL1 (37%, 37% and 26%, respectively). Grades 2 and 3 tumors showed 2+ to 3+ HA (94%) and HYAL1 (79%) staining. HA was expressed in tumor associated stroma and in tumor cells, whereas only tumor cells expressed HYAL1. In bladder tumor tissues HYAL1 expression was confirmed by immunoblot analysis. In 33 of the 34 patients (97%) with bladder cancer from whom urine and tumor tissue specimens were obtained at the same time 2+ to 3+ staining of HA and/or HYAL1 in 12 and 21, respectively, constituted a positive HA-HAase urine test (kappa = 0.945). CONCLUSIONS To our knowledge this is the first report of HA localization in bladder tissues and of HYAL1 in any normal or tumor tissue. A close correlation of elevated HA and HYAL1 levels in tumor tissues with a positive HA-HAase urine test indicates that in patients with bladder cancer tumor associated HA and HYAL1 are secreted in urine, causing the HA-HAase test to be positive.

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.