Angelika Tölle

GOLPH2 protein expression as a novel tissue biomarker for prostate cancer: implications for tissue-based diagnostics

GOLPH2 is coding the 73-kDa type II Golgi membrane antigen GOLPH2/GP73. Upregulation of GOLPH2 mRNA has been recently reported in expression array analyses of prostate cancer. As GOLPH2 protein expression in prostate tissues is currently unknown, this study aimed at a comprehensive analysis of GOLPH2 protein in benign and malignant prostate lesions. Immunohistochemically detected GOLPH2 protein expression was compared with the basal cell marker p63 and the prostate cancer marker α-methylacyl-CoA racemase (AMACR) in 614 radical prostatectomy specimens. GOLPH2 exhibited a perinuclear Golgi-type staining pattern and was preferentially seen in prostatic gland epithelia. Using a semiquantitative staining intensity score, GOLPH2 expression was significantly higher in prostate cancer glands compared with normal glands (P<0.001). GOLPH2 protein was upregulated in 567 of 614 tumours (92.3%) and AMACR in 583 of 614 tumours (95%) (correlation coefficient 0.113, P=0.005). Importantly, GOLPH2 immunohistochemistry exhibited a lower level of intratumoral heterogeneity (25 vs 45%). Further, GOLPH2 upregulation was detected in 26 of 31 (84%) AMACR-negative prostate cancer cases. These data clearly suggest GOLPH2 as an additional ancillary positive marker for tissue-based diagnosis of prostate cancer.

Identification of Stanniocalcin 2 as Prognostic Marker in Renal Cell Carcinoma

BACKGROUND For an individualized therapy in renal cell carcinoma (RCC), there is a clear need for novel prognostic biomarkers to ensure adequate risk stratification and help with the choice of therapy options. OBJECTIVE To identify new secreted biomarkers for diagnosis and estimation of prognosis in RCC. DESIGN, SETTING, AND PARTICIPANTS A meta-analysis of published microarray data was performed. Stanniocalcin 2 (STC2), a glycoprotein hormone that is involved in regulatory effects on calcium and phosphate transport in the kidney, was found overexpressed in tumors and hence analyzed in detail. Kidney tissue samples derived from 108 patients with RCC undergoing radical nephrectomy between July 2003 and January 2006 were used to validate and estimate the potential of STC2 as a biomarker for RCC. MEASUREMENTS STC2, found upregulated in clear cell RCC, was analyzed in detail using real-time reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunohistochemistry. Furthermore, STC2 protein expression determined on a tissue microarray was correlated to clinical pathologic parameters, including patient survival. RESULTS AND LIMITATIONS STC2 was upregulated at the mRNA and protein levels in RCC. In normal renal tissue, STC2 expression was limited to distal tubuli and glomeruli, whereas in tumor a strong cytoplasmic and also membranous staining was detected. STC2 expression was found in clear cell, chromophobe, and papillary RCC. Strong cytoplasmic STC2 expression was significantly associated with shorter patient survival in Kaplan-Meier analyses. In the group of patients without metastases, cytoplasmic STC2 expression was also found as a significant independent risk factor in multivariate analysis. A limitation of the study is the small number of patients. CONCLUSIONS Increased cytoplasmic STC2 expression correlated with conventional indicators of aggressiveness of RCC and shorter overall patient survival times. STC2 could become an adjunct tissue biomarker that may be useful in the postoperative risk stratification of RCC patients.

ADAM9 is highly expressed in renal cell cancer and is associated with tumour progression

BackgroundA Disintegrin And Metalloprotease (ADAM) 9 has been implicated in tumour progression of various solid tumours, however, little is known about its role in renal cell carcinoma. We evaluated the expression of ADAM9 on protein and transcript level in a clinico-pathologically characterized renal cell cancer cohort.Methods108 renal cancer cases were immunostained for ADAM9 on a tissue-micro-array. For 30 additional cases, ADAM9 mRNA of microdissected tumour and normal tissue was analyzed via quantitative RT-PCR. SPSS 14.0 was used to apply crosstables (Fishers exact test and χ2-test), correlations and univariate as well as multivariate survival analyses.ResultsADAM9 was significantly up-regulated in renal cancer in comparison to the adjacent normal tissue on mRNA level. On protein level, ADAM9 was significantly associated with higher tumour grade, positive nodal status and distant metastasis. Furthermore, ADAM9 protein expression was significantly associated with shortened patient survival in the univariate analysis.ConclusionADAM9 is strongly expressed in a large proportion of renal cell cancers, concordant with findings in other tumour entities. Additionally, ADAM9 expression is significantly associated with markers of unfavourable prognosis. Whether the demonstrated prognostic value of ADAM9 is independent from other tumour parameters will have to be verified in larger study cohorts.

Identification of microRNAs in blood and urine as tumour markers for the detection of urinary bladder cancer

Since differential expression of microRNAs (miRNAs) has been found to be highly associated with several types of cancer, the goal of the present study was to identify an miRNA fingerprint as a non‑invasive diagnostic tool to detect urinary bladder cancer using the easily accessible samples of whole blood and urine. Blood and urine samples from 4 controls and from patients suffering from superficial and invasive bladder cancer were analyzed using miRNA microarray consisting of 754 human miRNAs from the Sanger database v14. Using RT‑qPCR technique, 6 of the differentially expressed miRNAs were validated in the controls (20 blood, 19 urine samples) and patients with superficial (18 blood, 16 urine samples) or invasive (20 blood and urine samples each) tumours. Three blood miRNAs (miR‑26b‑5p, miR‑144‑5p, miR‑374‑5p) were found to be significantly upregulated in invasive bladder tumour patients (P<0.05) when compared to the control group. The expression of 2 miRNAs (miR‑618, miR‑1255b‑5p) in the urine of patients with invasive tumours was significantly (P<0.05) increased in comparison to the control group. Blood miR‑26b‑5p detected the presence of invasive bladder tumours with 94% specificity and 65% sensitivity. The urine miR‑1255b‑5p reached 68% specificity and 85% sensitivity in the diagnosis of invasive tumours. This pilot study represents the first characterization of an miRNA profile for urinary bladder tumours in whole blood samples. In addition, it was shown that invasive bladder tumours could be identified by differentially expressed urine miRNAs. Further studies are needed to test the clinical usefulness for bladder cancer detection and surveillance.

Fatty acid binding proteins (FABPs) in prostate, bladder and kidney cancer cell lines and the use of IL-FABP as survival predictor in patients with renal cell carcinoma.

BackgroundFatty acid binding proteins (FABP) play an important role in carcinogenesis. Modified FABP expression patterns were described for prostate, bladder and for renal cell carcinoma. Studies on metabolic relationships and interactions in permanent cell lines allow a deeper insight into molecular processes. The aim of this study is therefore a systematic overview on mRNA and protein expressions of seven FABPs in frequently used urological cell lines.MethodsNine cell lines of renal carcinomas, seven of urinary bladder carcinomas, and five of prostate carcinomas were investigated. Quantitative RT-qPCR and western blotting were used to determine different FABPs. In addition, 46 paired cancerous and noncancerous tissue samples from nephrectomy specimen with renal cell carcinomas were investigated regarding the ileum FABP mRNA expression level and associated with survival outcome.ResultsGeneral characteristics of all urological carcinoma cell lines were the expression of E-and IL-FABP on mRNA and protein level, while the expressions differed between the cell lines. The protein expression was not always congruent with the mRNA expression. Renal cell carcinoma cell lines showed expressions of L-, H- and B-FABP mRNA in addition to the general FABP expression in five out of the eight investigated cell lines. In bladder cancer cell lines, we additionally found the expression of A-FABP mRNA in six cell lines, while H-FABP was present only in three cell lines. In prostate cancer cell lines, a strong reduction of A- and E- FABP mRNA was observed. The expression of B-FABP mRNA and protein was observed only in the 22 RV-1 cells. IL-FABP mRNA was over-expressed in renal tumour tissue. The IL-FABP ratio was identified as an independent indicator of survival outcome.ConclusionsDistinctly different FABP expression patterns were observed not only between the cell lines derived from the three cancer types, but also between the cell lines from the same cancer. The FABP patterns in the cell lines do not always reflect the real situation in the tumours. These facts have to be considered in functional studies concerning the different FABPs.

Brain-type and liver-type fatty acid-binding proteins: new tumor markers for renal cancer?

BackgroundRenal cell carcinoma (RCC) is the most common renal neoplasm. Cancer tissue is often characterized by altered energy regulation. Fatty acid-binding proteins (FABP) are involved in the intracellular transport of fatty acids (FA). We examined the level of brain-type (B) and liver-type (L) FABP mRNA and the protein expression profiles of both FABPs in renal cell carcinoma.MethodsPaired tissue samples of cancerous and noncancerous kidney parts were investigated. Quantitative RT-PCR, immunohistochemistry and western blotting were used to determine B- and L-FABP in tumor and normal tissues. The tissue microarray (TMA) contained 272 clinico-pathologically characterized renal cell carcinomas of the clear cell, papillary and chromophobe subtype. SPSS 17.0 was used to apply crosstables (χ2-test), correlations and survival analyses.ResultsB-FABP mRNA was significantly up-regulated in renal cell carcinoma. In normal tissue B-FABP mRNA was very low or often not detectable. RCC with a high tumor grading (G3 + G4) showed significantly lower B-FABP mRNA compared with those with a low grading (G1 + G2). Western blotting analysis detected B-FABP in 78% of the cases with a very strong band but in the corresponding normal tissue it was weak or not detectable. L-FABP showed an inverse relationship for mRNA quantification and western blotting. A strong B-FABP staining was present in 52% of the tumor tissues contained in the TMA. In normal renal tissue, L-FABP showed a moderate to strong immunoreactivity in proximal tubuli. L-FABP was expressed at lower rates compared with the normal tissues in 30.5% of all tumors. There was no correlation between patient survival times and the staining intensity of both FABPs.ConclusionWhile B-FABP is over expressed in renal cell carcinoma in comparison to normal renal tissues L-FABP appears to be reduced in tumor tissue. Although the expression behavior was not related to the survival outcome of the RCC patients, it can be assumed that these changes indicate fundamental alterations in the fatty metabolism in the RCC carcinogenesis. Further studies should identify the role of both FABPs in carcinogenesis, progression and with regard to a potential target in RCC.

KLK15 is a prognostic marker for progression-free survival in patients with radical prostatectomy

In search of biomarkers for prostate cancer, we evaluated the expression of the human kallikrein‐related peptidase KLK15 in samples of prostatic adenocarcinomas from radical prostatectomies. Twenty‐five pairs of cancerous and adjacent normal prostatic tissue were selected by laser capture microdissection. The tissue was used for quantification of KLK15 mRNA by reverse‐transcriptase polymerase chain reaction. Immunohistochemical expression of the KLK15 protein in 193 samples of prostatic adenocarcinoma was analysed in relation to clinicopathological parameters of the patients and disease progression. Expression of KLK15 correlated with the pathological tumour stage and Gleason score of the cases, both at mRNA and at protein level. While mRNA expression in the tumour was elevated, the protein level of KLK15 was reduced compared with adjacent normal tissue and to prostatic intraepithelial neoplasia. Univariate Kaplan‐Meier analysis showed a significant association of dichotomised KLK15 levels with disease progression defined by prostate‐specific antigen relapse (p = 0.001). Multivariate analysis according to the Cox proportional hazards regression model identified dichotomised KLK15 expression, corrected for the patient parameters age, preoperative prostate‐specific antigen level, pathological tumour stage, Gleason score and surgical margin status, as an independent prognostic factor for poor outcome (inclusion model, hazard ratio 1.802, 95% confidence interval 1.037–3.132, p = 0.037). We suggest KLK15 as a new independent tumour marker for patients at risk for disease progression after radical prostatectomy.

An Epigenetic Screen Unmasks Metallothioneins as Putative Contributors to Renal Cell Carcinogenesis

Objective: Functional epigenetic studies aimed to re-express transcriptionally silenced genes in renal cell carcinoma (RCC) may facilitate the ongoing search for appropriate markers supporting clinical decision-making. Methods: The RCC cell line A-498 was treated with the DNA methyltransferase inhibitor zebularine under low-cytotoxicity conditions. RNA chip analyses revealed several upregulated transcripts that were further validated by qPCR on 49 matched pairs of human kidney tissues to identify suitable marker candidates. Results: Members of the metallothionein (MT) group were remarkably downregulated in tumor tissues. MT1G and MT1H expression was decreased in 98% of cases, whereas MT2A expression was downregulated in 73% of all cases. Comparison of 308 reactivated transcripts upregulated more than 1.5-fold to published data revealed a high number of shared candidates, which supports the consistency of this experimental approach. Conclusion: MTs were found to be transcriptionally inactivated in human RCC. Our observations support the hypothesis of a possible involvement of these metalloproteins in renal cell carcinogenesis. Additional functional studies of these genes may provide clues for understanding renal cancers as essentially metabolic diseases.

Importance of brain‑type fatty acid binding protein for cell-biological processes in human renal carcinoma cells

The molecular mechanisms underlying renal cell carcinoma (RCC) development and progression are still not completely understood. The importance of fatty acid binding proteins (FABP) for the progression of carcinomas has been shown for several tumors. However, the importance of brain-type FABP (B‑FABP) in cell-biological processes in renal carcinoma cells is unknown. Therefore, it was the aim of this study to evaluate the role of B‑FABP in processes such as proliferation, migration and invasion. By using the approach of down- and up-regulation of B‑FABP in human kidney carcinoma cells Caki‑2 and Caki‑1, the potential participation of B‑FABP in proliferation, migration and invasion was demonstrated. B‑FABP was down-regulated at both mRNA and protein levels following treatment of Caki‑2 cells with B‑FABP siRNA. Down-regulation of B‑FABP decreased cell proliferation and migration but did not affect invasion. The transfection of Caki‑1 cells with human B‑FABP cDNA generated an increment of B‑FABP mRNA but the protein was not detectable. Transfected Caki‑1 cells developed a faster proliferation compared to untreated cells. An effect on the process of invasion was not observed. Our data suggest that B‑FABP is involved in cell proliferation and migration of human renal carcinoma cells. The detailed molecular mechanisms remain to be elucidated.

miRNA panels as biomarkers for bladder cancer.

AIM Specific miRNA profiles have been identified for several samples from patients with bladder cancer. The results are not always congruent and partly contradictory. A comparison of published data was performed to select potential markers. MATERIALS & METHODS A literature search in PubMed identified 79 articles published prior to June 2013. Reports regarding the detection of miRNAs in urine and blood have rarely been published; to date, nine respectively three articles are available. RESULTS The comparison of published data proved the utility of miRNAs as diagnostic and prognostic indicators of bladder cancer. In urine samples from bladder cancer patients, seven miRNAs were concordantly expressed with tumor tissues. CONCLUSION Standardization is strictly required in pre-analytics and methods of miRNA measurements.