Molecular characterization of kidney cancer: association of hyaluronic acid family with histological subtypes and metastasis.

BACKGROUND: Molecular profiling of renal cell carcinomas (RCCs) may improve the distinction between oncocytoma and malignant RCC subtypes and aid in early detection of metastasis. The hyaluronic acid (HA) family includes HA synthases (HAS1, HAS2, HAS3), hyaluronidases (HYAL-1, HYAL-2, HYAL-3, HYAL-4, PH20, HYAL-P1), and HA receptors (CD44s, CD44v, RHAMM). HA family members promote tumor growth and metastasis. The authors evaluated the expression of HA family members in kidney specimens. METHODS: By using quantitative polymerase chain reaction, mRNA levels of 12 HA family members were measured in tumor specimens obtained from 86 consecutive patients undergoing nephrectomy; 80 of them also provided normal specimens. Mean and median follow-up were 15.2 ± 8.8 and 13.8 months. RCC specimens included clear cell RCC: 65; papillary: 10; chromophobe: 5; oncocytoma: 6; metastasis positive: 17. RESULTS: Median HAS1, CD44s, and RHAMM transcript levels were elevated 3- to 25-fold in clear cell RCC and papillary and chromophobe tumors when compared with normal tissues. HYAL-4, CD44s, and RHAMM levels were elevated 4- to 12-fold in clear cell RCC and papillary tumors when compared with oncocytomas; only HYAL-4 levels distinguished between chromophobe and oncocytoma (P = .009). CD44s and RHAMM levels were significantly higher in tumors <4 cm (510 ± 611 and 19.6 ± 20.8, respectively) when compared with oncocytoma (46.4 ± 20 and 3.8 ± 2.5; P ≤ .006). In univariate and multivariate analyses, CD44s (P < .0001), RHAMM (P < .0001), stage, tumor size, and/or renal vein involvement were significantly associated with metastasis. The combined CD44s + RHAMM marker had 82% sensitivity and 86% specificity to predict metastasis. CONCLUSIONS: CD44s and RHAMM levels distinguish between oncocytoma and RCC subtypes regardless of tumor size and are potential predictors of RCC metastasis.

Chemokine and chemokine receptor expression in kidney tumors: molecular profiling of histological subtypes and association with metastasis.

PURPOSE: Molecular characterization of renal cell carcinoma may help differentiate benign oncocytoma from malignant renal cell carcinoma subtypes and predict metastasis. Chemokines, eg IL-8 and chemokine receptors such as CXCR4 and 7, promote inflammation and metastasis. SDF-1 is a CXCR4 and 7 ligand with 6 known isoforms. We evaluated the expression of these chemokines and chemokine receptors in kidney specimens. MATERIALS AND METHODS: Using quantitative polymerase chain reaction we measured mRNA levels of IL-8, CXCR4 and 7, and SDF1 isoforms α, ß and γ in a total of 166 specimens from 86 patients, including 86 tumor samples and 80 matched normal kidney samples. Mean ± SD followup was 18.9 ± 12 months (median 19.5). Renal cell carcinoma specimens included the clear cell, papillary and chromophobe subtype in 65, 10 and 5 cases, respectively, and oncocytoma in 6. A total of 17 cases were positive for metastasis. RESULTS: Median CXCR4 and 7, and SFD1-γ levels were increased twofold to tenfold. SDF1-α and ß were unchanged or lower in clear cell renal cell carcinoma and papillary tumors than in normal tissue. Median SDF1-γ, IL-8, and CXCR4 and 7 were increased threefold to fortyfold in chromophobe tumors compared to oncocytoma. CXCR4 and 7 were increased in tumors less than 4 cm (mean 3,057 ± 2,230 and 806 ± 691) compared to oncocytoma (336 ± 325 and 201 ± 281, respectively, p ≤0.016). On multivariate analysis CXCR4 (p = 0.01), CXCR7 (p = 0.02) and SDF1-ß (p = 0.005) were independently associated with metastasis. Combined CXCR7 plus SDF1-α and CXCR7 plus IL-8 markers showed the highest sensitivity (71% to 81%) and specificity (75% to 80%) of all individual or combined markers. CONCLUSIONS: Chemokines and chemokine receptors differentiate renal cell carcinoma and oncocytoma. Combined SDF1-α plus CXCR7 and IL-8 plus CXCR7 markers have about 80% accuracy for predicting renal cell carcinoma metastasis.

HYAL4-V1/Chondroitinase (Chase) Drives Gemcitabine Resistance and Predicts Chemotherapy Failure in Patients with Bladder Cancer.

PURPOSE: Gemcitabine-based chemotherapy regimens are first-line for several advanced cancers. Because of better tolerability, gemcitabine + cisplatin is a preferred neoadjuvant, adjuvant, and/or palliative chemotherapy regimen for advanced bladder cancer. Nevertheless, predicting treatment failure and overcoming resistance remain unmet clinical needs. We discovered that splice variant (V1) of HYAL-4 is a first-in-class eukaryotic chondroitinase (Chase), and CD44 is its major substrate. V1 is upregulated in bladder cancer and drives a malignant phenotype. In this study, we investigated whether V1 drives chemotherapy resistance. EXPERIMENTAL DESIGN: V1 expression was measured in muscle-invasive bladder cancer (MIBC) specimens by qRT-PCR and IHC. HYAL-4 wild-type (Wt) and V1 were stably expressed or silenced in normal urothelial and three bladder cancer cell lines. Transfectants were analyzed for chemoresistance and associated mechanism in preclinical models. RESULTS: V1 levels in MIBC specimens of patients who developed metastasis, predicted response to gemcitabine + cisplatin adjuvant/salvage treatment and disease-specific mortality. V1-expressing bladder cells were resistant to gemcitabine but not to cisplatin. V1 expression neither affected gemcitabine influx nor the drug-efflux transporters. Instead, V1 increased gemcitabine metabolism and subsequent efflux of difluorodeoxyuridine, by upregulating cytidine deaminase (CDA) expression through increased CD44-JAK2/STAT3 signaling. CDA inhibitor tetrahydrouridine resensitized V1-expressing cells to gemcitabine. While gemcitabine (25-50 mg/kg) inhibited bladder cancer xenograft growth, V1-expressing tumors were resistant. Low-dose combination of gemcitabine and tetrahydrouridine abrogated the growth of V1 tumors with minimal toxicity. CONCLUSIONS: V1/Chase drives gemcitabine resistance and potentially predicts gemcitabine + cisplatin failure. CDA inhibition resensitizes V1-expressing tumors to gemcitabine. Because several chemotherapy regimens include gemcitabine, our study could have broad significance.

A Novel Splice Variant of HYAL-4 Drives Malignant Transformation and Predicts Outcome in Patients with Bladder Cancer.

PURPOSE: Poor prognosis of patients with muscle-invasive bladder cancer that often metastasizes drives the need for discovery of molecular determinants of bladder cancer progression. Chondroitin sulfate proteoglycans, including CD44, regulate cancer progression; however, the identity of a chondroitinase (Chase) that cleaves chondroitin sulfate from proteoglycans is unknown. HYAL-4 is an understudied gene suspected to encode a Chase, with no known biological function. We evaluated HYAL-4 expression and its role in bladder cancer. EXPERIMENTAL DESIGN: In clinical specimens, HYAL-4 wild-type (Wt) and V1 expression was evaluated by RT-qPCR, IHC, and/or immunoblotting; a novel assay measured Chase activity. Wt and V1 were stably expressed or silenced in normal urothelial and three bladder cancer cell lines. Transfectants were analyzed for stem cell phenotype, invasive signature and tumorigenesis, and metastasis in four xenograft models, including orthotopic bladder. RESULTS: HYAL-4 expression, specifically a novel splice variant (V1), was elevated in bladder tumors; Wt expression was barely detectable. V1 encoded a truncated 349 amino acid protein that was secreted. In bladder cancer tissues, V1 levels associated with metastasis and cancer-specific survival with high efficacy and encoded Chase activity. V1 cleaved chondroitin-6-sulfate from CD44, increasing CD44 secretion. V1 induced stem cell phenotype, motility/invasion, and an invasive signature. CD44 knockdown abrogated these phenotypes. V1-expressing urothelial cells developed angiogenic, muscle-invasive tumors. V1-expressing bladder cancer cells formed tumors at low density and formed metastatic bladder tumors when implanted orthotopically. CONCLUSIONS: Our study discovered the first naturally-occurring eukaryotic/human Chase and connected it to disease pathology, specifically cancer. V1-Chase is a driver of malignant bladder cancer and potential predictor of outcome in patients with bladder cancer.

Cell adhesive affinity does not dictate primitive endoderm segregation and positioning during murine embryoid body formation.

The classical cell sorting experiments undertaken by Townes and Holtfreter described the intrinsic propensity of dissociated embryonic cells to self-organize and reconcile into their original embryonic germ layers with characteristic histotypic positioning. Steinberg presented the differential adhesion hypothesis to explain these patterning phenomena. Here, we have reappraised these issues by implementing embryoid bodies to model the patterning of epiblast and primitive endoderm layers. We have used combinations of embryonic stem (ES) cells and their derivatives differentiated by retinoic acid treatment to model epiblast and endoderm cells, and wild-type or E-cadherin null cells to represent strongly or weakly adherent cells, respectively. One cell type was fluorescently labeled and reconstituted with another heterotypically to generate chimeric embryoid bodies, and cell sorting was tracked by time-lapse video microscopy and confirmed by immunostaining. When undifferentiated wild-type and E-cadherin null ES cells were mixed, the resulting cell aggregates consisted of a core of wild-type cells surrounded by loosely associated E-cadherin null cells, consistent with the differential adhesion hypothesis. However, when mixed with undifferentiated ES cells, the differentiated primitive endoderm-like cells sorted to the surface to form a primitive endoderm layer irrespective of cell-adhesive strength, contradicting the differential adhesion hypothesis. We propose that the primitive endoderm cells reach the surface by random movement, and subsequently the cells generate an apical/basal polarity that prevents reentry. Thus, the ability to generate epithelial polarity, rather than adhesive affinity, determines the surface positioning of the primitive endoderm cells.

Association of hyaluronic acid family members (HAS1, HAS2, and HYAL-1) with bladder cancer diagnosis and prognosis.

BACKGROUND: Cancer biomarkers are the backbone for the implementation of individualized approaches to bladder cancer (BCa). Hyaluronic acid (HA) and all 7 members of the HA family, that is, HA synthases (HA1, HA2, HA3), HYAL-1 hyaluronidase, and HA receptors (CD44s, CD44v, and RHAMM), function in tumor growth and progression. However, the diagnostic and prognostic potential of these 7 HA family members has not been compared simultaneously in any cancer. We evaluated the diagnostic and prognostic potential of HA family members in BCa. METHODS: Using quantitative PCR and immunohistochemistry, expression of HA family members was evaluated in prospectively collected bladder tissues (n = 72); mean and median follow-up were 29.6 ± 5.3 and 24 months, respectively. Transcript levels were also measured in exfoliated urothelial cells from urine specimens (n = 148). RESULTS: Among the HA family members, transcript levels of the HA synthases, HYAL-1, CD44v, and RHAMM were 4- to 16-fold higher in BCa tissues than in normal tissues (P < .0001); however, CD44s levels were lower. In univariate and multivariate analyses, tumor stage (P = .003), lymph node invasion (P = .033), HYAL-1 (P = .019), and HAS1 (P = .027) transcript levels, and HYAL-1 staining (P = .021) were independently associated with metastasis. Tumor stage (P = .019) and HYAL-1 (P = .046) transcript levels were also associated with disease-specific mortality. Although HA synthase and HYAL-1 transcript levels were elevated in exfoliated urothelial cells from BCa patients, the combined HAS2-HYAL-1 expression detected BCa with an overall sensitivity of 85.4% and a specificity of 79.5% and predicted BCa recurrence within 6 months (P = .004; RR = 6.7). CONCLUSIONS: HYAL-1 and HAS1 expression predicted BCa metastasis, and HYAL-1 expression also predicted disease-specific survival. Furthermore, the combined HAS2-HYAL-1 biomarker detected BCa and significantly predicted its recurrence.

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.

CXC receptor-1 silencing inhibits androgen-independent prostate cancer.

The CXC receptor-1 (CXCR1) is a coreceptor for interleukin-8 (IL-8) and is expressed on both normal and tumor cells. The function of CXCR1 in prostate cancer was investigated by silencing its expression, using RNA interference. We established stable cell colonies of PC-3 cells, depleted of CXCR1, using lentiviral plasmids (pLK0.1puro) generating small hairpin RNA (shRNA) against CXCR1 mRNA. Stable shRNA transfectants (PLK1-PLK5) that express significantly reduced CXCR1 mRNA (>or=90% down) and protein (>or=43% down) or vector-only transfectants (PC-3V) were characterized. PLK cells showed reduced cell proliferation (down, >or=66%), due to cell cycle arrest at G(1)-S phase, decreases in Cyclin D1, CDK4, phosphorylated Rb, and extracellular signal-regulated kinase 1/2 levels compared with those in PC-3V cells. CXCR1 depletion lead to increases in spontaneous apoptosis by mitochondria-mediated intrinsic mechanism and increases in proapoptotic proteins (BAD, 40%; BAX, 12%), but decreases in antiapoptotic proteins (BCL2, down 38%; BCL(xL), 20%). PLK2 cells grew as slow-growing tumors (decrease of 54%), compared with that of PC3V tumors in athymic mice. Ex vivo analyses of PLK2 tumor tissues showed reduced expression of Cyclin D1 and vascular endothelial growth factor, and increased apoptosis activity. Other IL-8-expressing prostate cancer cell lines also exhibited similar phenotypes when CXCR1 was depleted by CXCR1 shRNA transfection. In contrast to these cells, CXCR1 depletion had little effect on IL-8 ligand-deficient LNCaP cells. RNA interference rescue using mutated CXCR1 plasmids reversed the silencing effect of PLK2, thus demonstrating the specificity of phenotypic alteration by CXCR1 shRNA. These studies establish that CXCR1 promotes IL-8-mediated tumor growth.