Abstract 1161: Detection and identification of a miRNA expression profile from cell-free urine: Potential utility in bladder cancer

Introduction/Objective: MicroRNAs are small, non-coding RNAs that have been shown to play an important role in tumorigenesis. There is differential expression of miRNA in cancer progression, and profiling of miRNA is promising for both diagnosis and treatment of malignant tumors. In this study we isolated RNA from cell-free urine in an attempt to characterize miRNA profiles indicating the presence of urothelial carcinoma and its potential use as a non-invasive assay to identify patients with cancer progression.

Methods: Urine was collected from patients diagnosed with bladder cancer and control patients with no history of cancer under an IRB-approved protocol. Urine was centrifuged and total RNA was isolated from the supernatants using the mirVana Paris™ kit. A total of 178 samples were grouped according to grade and stage (healthy controls (35), TaG1 (19), T1G3 (16), ≥T2 (30), carcinoma in situ (CIS; 28) and no evidence of disease following therapy (50). Seven hundred and thirty miRNAs were profiled by qRT-PCR on pooled samples within each group. Validation of selected miRNAs was performed on individual samples using qRT-PCR.

Results: Cell-free RNA was isolated from urine of 35 healthy controls and 143 patients with bladder cancer. Of the 730 miRNAs tested, 236 were detected in at least one of the pooled samples using a Ct cutoff of 35. The number of miRNAs detected in the pooled samples correlated with disease progression where the healthy control group and the ≥T2 group expressed 8 and 228 miRNAs, respectively. qRT-PCR of individual samples revealed a gradual increase of some miRNAs with disease progression. Statistical analysis adjusted for multiple comparisons demonstrated differences between groups based on miRNA expression levels. In addition, a panel of miRNAs was identified which discriminated between cancer and cancer-free patients.

Conclusion: This study demonstrates the successful isolation of miRNAs from cell-free urine. Utilizing non-invasive urine based assays, we identified a miRNA panel that can discriminate between cancer-free patients and patients with urinary carcinoma of the bladder. These findings provide evidence that profiling of miRNAs from cell-free urine holds the promise for the development of valuable clinical tools.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1161. doi:10.1158/1538-7445.AM2011-1161

Prognostic impact of the 2009 UICC/AJCC TNM staging system for renal cell carcinoma with venous extension

BACKGROUND

The prognostic significance of venous involvement and tumour thrombus level in renal cell carcinoma (RCC) remains highly controversial. In 2010, the American Joint Committee on Cancer (AJCC) and the Union International Centre le Cancer (UICC) revised the RCC staging system (7th edition) based on tumour thrombus level, differentiating the T stage of tumours limited to renal-vein-only involvement.

OBJECTIVE

We aimed to evaluate the impact of tumour thrombus extension in a multi-institutional cohort of patients.

DESIGN, SETTING, AND PARTICIPANTS

An international consortium of 11 institutions was established to retrospectively review a combined cohort of 1215 patients undergoing radical nephrectomy and tumour thrombectomy for RCC, including 585 patients with inferior vena cava (IVC) involvement or higher.

MEASUREMENTS

Predictive factors of survival, including histology, tumour thrombus level, nodal status, Fuhrman grade, and tumour size, were analysed.

RESULTS AND LIMITATIONS

A total of 1122 patients with complete data were reviewed. The median follow-up for all patients was 24.7 mo, with a median survival of 33.8 mo. The 5-yr survival was 43.2% (renal vein involvement), 37% (IVC below the diaphragm), and 22% with caval involvement above the diaphragm. On multivariate analysis, tumour size (hazard ratio [HR]: 1.64 [range: 1.03-2.59]; p=0.036), Fuhrman grade (HR: 2.26 [range: 1.65-3.1]; p=0.000), nodal metastasis (HR: 1.32 [range: 1.09-1.67]; p=0.005), and tumour thrombus level (HR: 2.10 [range: 1.53-3.0]; p=0.00) correlated independently with survival.

CONCLUSIONS

Based on analysis of the largest known cohort of patients with RCC along with IVC and atrial thrombus involvement, tumour thrombus level is an independent predictor of survival. Our findings support the changes to the latest AJCC/UICC staging system.

Novel ZEB1 expression in bladder tumorigenesis

What's known on the subject? and What does the study add? Epithelial-mesenchymal transition (EMT) is involved in tumor progression where the underlying cellular changes associated with EMT have been identified in in vitro models and confirmed in a limited number of in vivo studies. ZEB1, which targets E-cadherin repression, is a transcriptional regulator that has been implicated in EMT, and is associated with uterine and colorectal cancers. Regulation of ZEB1 expression has been shown to involve different microRNAs (miRNAs), identifying a potential role for miRNA in EMT. In the present study we have identified novel expression of ZEB1 in bladder tumours and shown a role for ZEB1 in enhanced migration and invasion potential in in vitro assays. Confirmation of ZEB1 expression in bladder tumours was shown in tissue microarrays (TMAs).

OBJECTIVE

To evaluate ZEB1 expression in bladder tumorigenesis and define a possible role for this transcription factor in urothelial carcinomas of the bladder (UCBs).

MATERIALS AND METHODS

Five hundred and fifty-eight samples were assembled in 10 tissue microarrays (TMAs; 263 non-muscle-invasive Ta/T1/Tis, 295 muscle-invasive T2-T4). All tumours were transitional cell carcinomas (TCCs) and processed for immunohistochemistry to assess nuclear ZEB1 expression. Expression levels of ZEB1 were modulated in bladder carcinoma cell lines CUBIII or UM-UC-3 after forced expression or shRNA knockdown, respectively. Protein expression levels were determined using western blot analysis and transfectants were assessed for migration and invasion potential in standard in vitro assays.

RESULTS

Nuclear ZEB1 expression was recorded in 22.8% of non-muscle-invasive UCBs and 21.7% of muscle-invasive UCBs, including 24.1% grade I/II and 21.1% grade III tumours, and absent in normal bladder mucosa. No significant correlation was observed for tumour stage and grade, nodal involvement, vascular invasion, metastasis and overall or cancer-specific survival. The introduction or knockdown of ZEB1 expression in bladder carcinoma cell lines showed enhanced or reduced migration and invasive potential, respectively. Changes in ZEB1 expression were accompanied by altered microRNA (miRNA) expression underlying events linked to epithelial-mesenchymal transition (EMT).

CONCLUSION

The results in the present study showed novel expression of ZEB1 in bladder cancer in the absence of a link to clinical variables of change, including metastasis and survival. However, in vitro assays showed enhanced or reduced migration and invasion after the introduction or reduction of ZEB1, respectively, in transfected bladder cell lines. Modulation in expression of ZEB1 was closely linked to changes in the miR-200 family along with alternative known prognostic indicators of bladder tumour progression.

Identification of tumor and invasion suppressor gene modulators in bladder cancer by different classes of histone deacetylase inhibitors using reverse phase protein arrays

PURPOSE

We assessed the ability of different classes of histone deacetylase inhibitors to target tumor and invasive suppressor genes in a panel of bladder carcinoma cell lines using reverse phase protein arrays.

MATERIALS AND METHODS

Three poorly, moderately and highly invasive cell lines were exposed to histone deacetylase inhibitors, trichostatin A, apicidin, valproic acid (Sigma) and MS-275 (AXXORA) for 0 to 36 hours. Lysates were harvested and arrayed in a 10-fold dilution series in duplicate. Data points were collected and analyzed using a concentration interpolation methodology after normalization.

RESULTS

Protein expression profiles revealed up-regulation of gamma-catenin in highly invasive lines, and alpha-catenin in moderately and highly invasive lines after exposure to all histone deacetylase inhibitors, apicidin and MS-275, respectively. Gelsolin was up-regulated in poorly and moderately invasive lines after exposure to all histone deacetylase inhibitors. Desmoglein was down-regulated in poorly and moderately invasive cell lines by all 4 histone deacetylase inhibitors, in addition to decreased FAK (Transduction Laboratories) expression in moderately and highly invasive lines exposed to valproic acid and MS-275.

CONCLUSIONS

Different histone deacetylase inhibitor classes have the potential to modulate tumor and invasive suppressor gene expression, identifying histone deacetylase inhibitors as potential therapeutic agents for bladder cancer. Reverse phase protein arrays enable high throughput screening of multiple compounds to assess the expression profile of specific protein groups targeted for therapy.

Abstract 3026: miR-203 and miR-205 expression profiles are predictive of high grade non-invasive urothelial carcinoma progression

Introduction: MicroRNA (miRNA) has been shown to play a role in regulating the expression of genes involved in tumor suppression and oncogenesis. High-grade, non-muscle-invasive urothelial carcinoma of the bladder (UCB) harbors a significant risk of progression to muscle invasion. In this study, we sought to identify miRNAs differentially expressed in non-progressive high-grade non-muscle-invasive UCB as compared to pathologically identical lesions that progress to muscle invasion.

Methods: Total RNA was extracted from formalin fixed paraffin-embedded tissue (FFPE) of high-grade non-muscle-invasive (TaG3/T1G3) UCB lesions. Patients were categorized into two groups: non-progressors with at least 3 years follow-up or progressors advancing to ≥T2. Exclusion criteria were previous tumors of the upper tract, prior systemic chemotherapy or previous pelvic irradiation. Total RNA was pooled for microarray analysis from a subset of the non-progressor and progressor groups. Data was analyzed using the LOWESS normalization method. Expression profiles of miRNAs were verified with qRT-PCR on 89 high-grade non-muscle-invasive UCB (68 non-progressors and 21 progressors). Logistic regression analysis was performed to identify miRNAs predictive of tumor progression.

Results: MicroRNA microarray data identified a panel of miRNAs (25) with potential involvement in the progression to invasion of high-grade non-muscle-invasive UCB. 36% of these miRNAs were upregulated and 64% were downregulated in the progressor samples. To validate differential expression of these miRNAs, qRT-PCR was performed on the 89 FFPE tissue samples. Logistic regression analysis of qRT-PCR data revealed decreased expression of miR-203 and miR-205 as predictive of progression (p = 0.031 and p = 0.045, respectively). Subsequent qRT-PCR with miR-203 and miR-205 on 31 muscle-invasive tumor samples (≥T2) showed expression profiles that were similar to those of the non-invasive progressors.

Conclusions: In this study, we have shown that miR-203 and miR-205 can identify patients with non-muscle- invasive UCB at high risk to progress to muscle-invasive disease. Our findings also suggest that such tumors have a biomolecular profile similar to muscle-invasive lesions. Further validation studies are underway to investigate additional miRNAs and determine the mechanism by which these miRNAs promote tumor invasion and progression. These results provide an important tool that can be used to prognosticate the clinical behavior of a very challenging subset of tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3026.

Endovascular temporary vessel occlusion with a reverse-thermosensitive polymer for bloodless minimally invasive renal surgery

PURPOSE

To demonstrate the feasibility of reversible vessel embolization with angiographic guidance for delivery of a rapid reverse-thermosensitive polymer to provide hemostasis as an aid for minimally invasive renal surgery in a porcine model.

MATERIALS AND METHODS

After isolation of the left kidney of seven anesthetized pigs (50-70 kg) with a surgical robot, a renal angiogram of both kidneys was obtained. A 5-F angiographic catheter was used to selectively embolize a lower-pole segmental artery of the right and left kidney with a thermosensitive polymer (LeGoo-XL). Distal and proximal embolization of the target vessel was compared. Degree and duration of hemostasis and reversibility was determined. After complete hemostasis was obtained angiographically, a partial robotic lower-pole nephrectomy was performed on the left kidney only.

RESULTS

Only proximal embolization provided controllable hemostasis. A 20% polymer concentration in a buffer solution of 40% saline solution and 40% iodine contrast medium by weight injected at room temperature resulted in a reproducible embolus for more than 30 minutes, the time needed to perform a partial nephrectomy. The radiographic appearance of the embolus was used to determine the total amount of polymer needed. Cold saline solution completely dissolved any residual polymer at the end of surgery.

CONCLUSIONS

Proximal arterial occlusion with a thermosensitive polymer can be rapidly reversed with selective intraarterial infusion of chilled saline solution. Preceding nephron-sparing surgery with transcatheter embolization of the relevant branch of the renal artery with the polymer can facilitate the procedure and ought to be investigated further.

A MicroRNA expression profile defining the invasive bladder tumor phenotype

OBJECTIVE

The purpose of this study was to identify microRNA (miRNA) involved in the transition between the noninvasive and invasive urothelial carcinoma of the bladder (UCB) phenotype.

METHODS

Differential expression of miRNA was identified in a microarray format between noninvasive and invasive UCB cell lines and confirmed using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) within this cell panel. Normalization of qRT-PCR with miR-222 was established from the microarray data and validated within a panel of 57 UCB tumors (26 noninvasive lesions (Ta/G1) and 31 invasive lesions (T2-T4). Pre-miR constructs were transfected into appropriate UCB cell lines to establish a change in invasive potential.

RESULTS

Differential expression of miRNAs was identified from microarray analysis and included reduced expression associated with miR-30b, miR-31, miR-141, miR-200a, miR-200b, miR-200c, miR-205, miR-21 in invasive lesions and elevated miR-99a in noninvasive UCB lesions. Reduced invasion potential was recorded in UM-UC-3, following pre-miR transfection, in all UCB cell lines with the exception of UM-UC-3/miR-30b transfectants. Our results identify a panel of miRNA modulated and expressed in invasive UCB tumors and demonstrates a role for them in the invasive phenotype.

CONCLUSIONS

The diagnostic test, based on the three most discriminatory miRNAs in our panel (miR-200c, miR-141, and miR-30b), showed a sensitivity of 100% and a specificity of 96.2%. Such a panel of miRNAs has the potential to identify invasive bladder tumors misclassified in pathologic assessment of bladder biopsy specimens.

A novel approach to using matrix metalloproteinases for bladder cancer

PURPOSE

Given the steadily growing cancer survivor population, increasing pressure has been placed on more effective clinical approaches and biomarker assays to manage care. For bladder cancer despite the high probability of recurrence the number of patients with recurrent disease is significantly lower than the number that remains cancer free at any monitoring interval. We developed a noninvasive urine assay using a novel approach to identify patients without recurrent cancer with extremely high confidence.

MATERIALS AND METHODS

Previous studies show that matrix metalloproteinases are increased in the urine of patients with cancer compared to that in disease-free individuals. To determine the clinical usefulness of these markers as monitors for bladder cancer recurrence we measured and compared metalloproteinase-2, metalloproteinase-9 and metalloproteinase-9/neutrophil gelatinase-associated lipocalin by enzyme-linked immunosorbent assay and zymography in a set of 530 samples, including 84 samples from patients with bladder cancer.

RESULTS

Initial studies using urine metalloproteinase to discriminate disease-free patients from those with bladder cancer resulted in 80% sensitivity (67 of 84) and 71% specificity (318 of 446) for metalloproteinase-9. By applying our novel Clinical Intervention Determining Diagnostic() clinical approach to metalloproteinase-9 we correctly identified 42% of cases that were cystoscopy negative with 98% negative predictive value.

CONCLUSIONS

A noninvasive urine diagnostic assay that uses metalloproteinases with the Clinical Intervention Determining Diagnostic could lead to more efficient treatment in bladder cancer survivors by decreasing the number of negative cystoscopies (42%), allowing physicians to more selectively monitor those at high risk.

A microRNA expression ratio defining the invasive phenotype in bladder tumors

OBJECTIVE

The goal of this study was to identify a microRNA (miRNA) signature in bladder cancer capable of differentiating superficial from invasive disease.

METHODS

Expression profiling of 343 miRNAs was performed in a microarray format using noninvasive and invasive bladder carcinoma cell lines with differential expression confirmed using a single molecule detection platform assay. miR-21 and miR-205 expression levels were determined in 53 bladder tumors (28 superficial and 25 invasive). Sensitivity, specificity, and a ROC curve were calculated to determine the discriminatory power of the miRNA ratio to predict invasion. Knockdown and forced expression of miRNAs was performed to evaluate their role in invasion.

RESULTS

Expression profiling of 343 miRNAs, using noninvasive and invasive bladder cell lines, revealed significant differential expression of 9 miRNAs. Cell lines characterized as invasive showed a miR-21:miR-205 ratio at least 10-fold higher than the quantitative ratio obtained from non-invasive cell lines. The same expression ratio was determined in 53 bladder tumors. From these results, we recorded a sensitivity and specificity of 100% and 78%, respectively, using a cutoff of 1.79 to predict an invasive lesion. The area under the receiver operator characteristic curve was 0.89. Using in vitro invasion assays, we have demonstrated a role for miR-21 in establishing the invasive phenotype of bladder carcinoma cells.

CONCLUSION

In this study, we identified a miR-21:miR-205 expression ratio that has the ability to distinguish between invasive and noninvasive bladder tumors with high sensitivity and specificity, with the potential to identify superficial lesions at high risk to progress.