Levels of Tissue Inhibitor of Metalloproteinases 1 in Plasma and Urine from Patients with Bladder Cancer

Aim

To assess the potential use of plasma and urine levels of tissue inhibitor of metalloproteinases 1 (TIMP-1) in urothelial cancer.

Methods

TIMP-1 levels were determined in urine and plasma from healthy donors (n=26), patients with bacterial bladder infection (n=24), urothelial bladder adenoma (n=3) or adenocarcinoma (n=7).

Results

Free and total TIMP-1 in plasma were weakly but significantly correlated with age; urinary TIMP-1 was not. A strong correlation between free and total TIMP-1 in plasma was observed, with an average ratio of 0.85. No correlation between total TIMP-1 in urine and plasma was found (p=0.55). No significant differences in free or total TIMP-1 in plasma were found between healthy individuals, patients with cystitis or bladder cancer (p=0.4). Urinary TIMP-1 levels were significantly increased in patients with cystitis (p=0.001). No apparent differences in TIMP-1 levels were found in patients with bladder cancer at different stages.

Conclusion

Our previous observation of a weak but significant correlation between plasma TIMP-1 and age was confirmed. Likewise, an association between free and total TIMP-1 in plasma with a ratio of 0.85 was established. No correlation between plasma and urine TIMP-1 was found. Measurement of TIMP-1 in plasma and/or urine is apparently not useful for the identification of bladder cancer.

Abstract 3833: Detection of prostate cancer associated DNA hypermethylation in diagnostic needle biopsies: Insight into field effects and heterogeneity

Prostate cancer (PC) is the fifth leading cause of cancer deaths among men worldwide and the second most common cancer form with an estimated 1.1 million diagnoses in 2012. Diagnosis is based on histological evaluation of needle biopsies by a trained pathologist. Despite the high number of diagnoses, PC is frequently missed in the initial set of biopsies. Thus, in more than 15% of patients with initial negative biopsies, PC is found in repeat biopsies. The aim of this project was to evaluate if DNA methylation-based cancer field effects can be detected in cancer-negative prostate biopsy samples for the nine genes HAPLN3, AOX1, GAS6, KLF8, MOB3B, CCDC181 (C1orf114), GABRE, SLC18A2, and GSTP1, and if this could be a potential novel diagnostic tool. Hypermethylation of these genes is known to be strongly associated with PC in prostatectomy specimens.

First, we confirmed the presence of hypermethylation of all genes in malignant (n = 48) compared to non-malignant biopsy tissue samples (n = 40) using quantitative methylation specific PCR (pBonferroni≤0.00002 in Mann Whitney U test, AUC range 0.80-0.98 in ROC analysis). Next, non-malignant biopsy samples from men with (n = 39) or without (n = 40) cancer in other biopsies were compared. Here, the methylation status of no single gene showed a significant correlation to the presence of PC in other biopsies. However, PC is a heterogeneous disease and a panel of markers could lead to increased sensitivity for PC if each marker adds little but complementary information. Indeed, a 4-gene model (HAPLN3/GSTP1/AOX1/SLC18A2) was able to separate the 2 groups of non-malignant samples with an AUC of 0.65 in ROC analysis (PPV = 100%, NPV = 59.7%), indicating the existence of an epigenetic cancer field effect. In our sample set, this corresponds to 12 out of 39 samples that would be identified as originating from PC patients based on the molecular analysis although no signs of malignancy were identified by pathology. Finally, to investigate epigenetic field effects and heterogeneity on a genomewide scale, we have analyzed multiple cancer foci, adjacent non-malignant and distant non-malignant samples from radical prostatectomy specimens from each of 4 patients with multifocal PC using the Infinium HumanMethylation450 BeadChip (Illumina). The results will be presented at the conference.

In summary, PC-specific hypermethylation of all nine genes was confirmed in diagnostic needle biopsies. Furthermore, DNA methylation based cancer field effects were detected for several of these genes, and a 4-gene model with potential to detect non-malignant samples from PC patients based on a DNA hypermethylation signature was identified. The results of our study suggest that detection of epigenetic field effects in cancer-negative prostate biopsy samples may be used to increase the sensitivity for PC detection.

Citation Format: Mia Moller, Siri H. Strand, Christa Haldrup, Soren Hoyer, Michael Borre, Torben Orntoft, Karina D. Sorensen. Detection of prostate cancer associated DNA hypermethylation in diagnostic needle biopsies: Insight into field effects and heterogeneity. [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 3833. doi:10.1158/1538-7445.AM2015-3833

Abstract 992: LIMD2 is a small LIM-only protein overexpressed in metastatic lesions which regulates cell motility and tumor progression by directly binding to and activating the integrin-linked-kinase

Proteins that communicate signals from the cytoskeleton to the nucleus are prime targets for effectors of metastasis as they often transduce signals regulating adhesion, motility and invasiveness. LIM domain proteins shuttle between the cytoplasm and the nucleus, and bind to partners in both compartments, often coupling changes in gene expression to extracellular cues and hence are a prime target for deregulation during tumor progression and metastasis. The LIM domain is a modular Zn finger structure, often found tandemly repeated in proteins. These LIM arrays often serve as scaffolds for assembling signal transduction apparatus. In this work, we characterize LIMD2 which is unique in that it encodes a single LIM domain. LIMD2 was originally identified as a transcript overexpressed in metastatic lesions but absent in the matched primary tumor from the same patient suggesting that it may be either a marker or effector of metastatic spread. We have shown that LIMD2 levels in fresh and archival tumors positively correlate with cell motility, metastatic potential and tumor grade in many different tumor types including bladder, melanoma, breast and thyroid tumors. LIMD2 directly contributes to these cellular phenotypes as shown by overexpression, knockdown and reconstitution experiments in cell culture models. Tumor cells with poor metastatic capability are converted to highly motile, invasive cells by expression of LIMD2 suggesting a dominant gain of function action. To understand the molecular mechanisms of its biological effects we determined its solution structure using NMR. The structure studies of LIMD2 revealed a classic LIM-domain structure containing a rigid hydrophobic core which bound 2 molecules of Zn. The 3D structure of LIMD2 was most highly related to the LIM1 domain of PINCH1, a core component of the Integrin Linked Kinase-Parvin-Pinch (IPP) complex. The IPP complex plays a key role in cell-cell and cell matrix interaction by transducing signals from membrane bound integrins to the nucleus. Structural and biochemical analyses revealed that LIMD2 bound directly to the kinase domain of ILK near the active site and strongly activated ILK kinase activity in vitro. Immunolocalization studies showed that LIMD2 and components of the IPP complex co-existed in focal adhesion plaques. Cells which were null for ILK failed to respond to the induction of motility and invasion by ectopic expression of LIMD2. This strongly suggests that LIMD2 potentiates its biological effects through direct interactions with ILK, a signal transduction pathway firmly linked to cell motility and invasion. In summary, we have defined LIMD2 as a new component of the signal transduction cascade that links integrin-mediated signaling to cell motility/metastatic behavior and may be a promising target for controlling tumor spread.

Citation Format: Hongzhuang Peng, Mehdi Taleb Zadeh Farrooji, Michael J. Osborne, Jeremy W. Prokop, Paul C. McDonald, Jayashree Karar, Zhaoyuan Hou, Mei He, Electron Kebebew, Torben Orntoft, Meenhard Herlyn, Andrew J. Caton, William Fredericks, Bruce Malkowicz, Christopher S. Paterno, Alexandra S. Carolin, David W. Speicher, Emmanuel Skordalakes, Qihong Huang, Shoukat S. Dedhar, Katherine L. B. Borden, Frank J. Rauscher. LIMD2 is a small LIM-only protein overexpressed in metastatic lesions which regulates cell motility and tumor progression by directly binding to and activating the integrin-linked-kinase. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 992. doi:10.1158/1538-7445.AM2014-992

LIMD2 is a small LIM-only protein overexpressed in metastatic lesions that regulates cell motility and tumor progression by directly binding to and activating the integrin-linked kinase

Proteins that communicate signals from the cytoskeleton to the nucleus are prime targets for effectors of metastasis as they often transduce signals regulating adhesion, motility, and invasiveness. LIM domain proteins shuttle between the cytoplasm and the nucleus, and bind to partners in both compartments, often coupling changes in gene expression to extracellular cues. In this work, we characterize LIMD2, a mechanistically undefined LIM-only protein originally found to be overexpressed in metastatic lesions but absent in the matched primary tumor. LIMD2 levels in fresh and archival tumors positively correlate with cell motility, metastatic potential, and grade, including bladder, melanoma, breast, and thyroid tumors. LIMD2 directly contributes to these cellular phenotypes as shown by overexpression, knockdown, and reconstitution experiments in cell culture models. The solution structure of LIMD2 that was determined using nuclear magnetic resonance revealed a classic LIM-domain structure that was highly related to LIM1 of PINCH1, a core component of the integrin-linked kinase-parvin-pinch complex. Structural and biochemical analyses revealed that LIMD2 bound directly to the kinase domain of integrin-linked kinase (ILK) near the active site and strongly activated ILK kinase activity. Cells that were null for ILK failed to respond to the induction of invasion by LIMD2. This strongly suggests that LIMD2 potentiates its biologic effects through direct interactions with ILK, a signal transduction pathway firmly linked to cell motility and invasion. In summary, LIMD2 is a new component of the signal transduction cascade that links integrin-mediated signaling to cell motility/metastatic behavior and may be a promising target for controlling tumor spread.

Expression of TIP60 (tat-interactive protein) and MRE11 (meiotic recombination 11 homolog) predict treatment-specific outcome of localised invasive bladder cancer

What's known on the subject? and What does the study add? Several studies have shown that defects in DNA-damage response are associated with good survival after chemotherapy and radiotherapy. Furthermore, loss of cell cycle regulators may be prognostic indicators of poor survival after cystectomy. However, the potential clinical impact of previous findings is hampered by insufficient validation of significant results in suitable cystectomy and radiotherapy cohorts. Here we use a large cohort of patients receiving radiotherapy to successfully validate the importance of MRE11 as a predictive marker of disease-specific survival (DSS). Furthermore, using two independent patient cohorts we show for the first time that TIP60 is a predictive marker of DSS after cystectomy. We show that combined use of TIP60 and MRE11 may hold the potential to guide treatment decisions.

OBJECTIVE

• To determine the association between the proteins: tat-interactive protein 60 kDa (TIP60), p16, meiotic recombination 11 homolog (MRE11), phosphorylated ataxia telangiectasia mutated (ATM), retinoblastoma protein (Rb), Ki67, and p53 and clinical outcome in invasive lymph node-negative bladder cancer.

PATIENTS AND METHODS

• Protein expression was measured by immunohistochemistry in cancer specimens from two independent cohorts of patients with bladder cancer treated with cystectomy (162 patients and 273) and one cohort of patients receiving radiotherapy (148). • Disease-specific survival (DSS) was used as the outcome measure, and patients with no disease-specific death were followed for a minimum of 36 months.

RESULTS

• TIP60 was significantly correlated with DSS in both cystectomy cohorts (hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.26-0.68, P < 0.001 and HR 0.45, 95% CI 0.28-0.72, P = 0.001). • MRE11 was significantly correlated with DSS in the cohort receiving radiotherapy (HR 0.64, 95% CI 0.47-0.86, P = 0.005). • P16 was significantly correlated with DSS in all three cohorts (HR 0.46, 95% CI 0.30-0.75, P = 0.032; HR 0.60, 95% CI 0.37-0.97, P = 0.032; HR 0.52, 95% CI 0.28-0.96, P = 0.001). • Rb was significantly correlated with DSS in one cystectomy cohort (HR 1.71, 95% CI 1.13-2.75, P = 0.017). • Ki67, p53, and pATM were not significantly correlated with DSS in any of the cohorts.

CONCLUSIONS

• TIP60 protein expression was a predictive marker for DSS after cystectomy in two independent cohorts. This novel marker was the strongest predictive factor in multivariate analysis in patients receiving cystectomy. • MRE11 was shown to be a predictive marker for DSS after radiotherapy. • We have shown that TIP60 and MRE11 hold the potential to guide patients with invasive bladder cancer to either cystectomy or radiotherapy. This study was based on retrospective material and consequently we suggest that these markers should be validated in a prospective study.

Abstract 4023: Genome-wide analysis of CpG island methylation identified OTX1, OSR1 and ONECUT2 as biomarkers for recurrent bladder cancer detection in voided urine

Cancers of the urinary bladder (BC) present as muscle-invasive (MIBC) or non-muscle invasive (NMIBC). Major problems with NMIBC are that 70% of the tumors will recur and 10-20% will eventually progress to MIBC. Therefore the patients are monitored by cystoscopy every 3-6 months after transurethral resection of the tumor in order to spot potential recurrences. DNA methylation has been shown to contribute to the pathogenesis cancer and may serve as useful biomarker. Recent studies showed promising urine methylation biomarkers for BC, but none of these were specifically tested for detection of recurrent BCs which are often smaller and hence more difficult to detect than primary tumors. Therefore we aimed to develop an assay specific for the diagnosis of recurrent bladder tumors in voided urine. From our earlier genome-wide study, we selected 8 candidate CGIs (CpG islands) methylated in BC to screen for the detection of recurrent bladder tumors in voided urine. We first screened these 8 CGIs on an independent set of 50 FFPE bladder tumors and 70 urines from age matched individuals without any history of BC as controls using BS-SNaPshot (Bisulfite specific single nucleotide primer extension assay). Subsequently, the 8 CGIs were investigated in a test set of 100 preTUR (before Trans Urethral Resection) urines associated with a concomitant recurrent tumor. We analyzed the sensitivity, specificity, AUC (area under the curve), PPV and NPV of all the individual markers and five best combinations. We then validated this on a separate cohort of 100 preTUR urines samples. Single marker OTX1 identified recurrent bladder tumors in voided urine with a sensitivity of 71% at a specificity of 90% with an AUC of 0.85 (CI: 0.80-0.91, P&lt;0.0001). A 3 gene methylation panel OTX1, ONECUT2 and OSR1 showed a sensitivity of 73% at a specificity of 90% with an AUC of 0.86 (CI: 0.80-0.91, P&lt; 0.0001). Combining this 3-gene panel methylation assay with FGFR3 (fibroblast growth factor receptor 3) mutation assay achieved a sensitivity of 78% at a specificity of 90% with an AUC of 0.87 (CI: 0.82-0.93, P&lt; 0.0001). This panel of markers showed a sensitivity of 100% in detecting bladder tumor tissue DNA. These markers were also investigated on 40 urines collected from patients who are recurrence free for a period of longer than 6 months. A total of 9/40 (22%) urines were positive in these recurrence free patients. The lower specificity of these samples could be due to the anticipatory effect that has been attributed to urine tests, i.e. urines test sees the tumor earlier than cystocopy. We also observed that multiple tumors from a patient are highly concordant in their methylation percentage, which underlines the usefulness of the markers. In summary the panel biomarkers that are identified will be able to detect the recurrent bladder tumors in voided urine, thereby helping in surveillance of patients with bladder cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4023. doi:1538-7445.AM2012-4023

Abstract 3654: Prognostic role of androgen receptor in bladder cancer

Aims: Hormone receptors are the prototype predictive marker in breast and prostate cancer. Hormone receptor positive cancers have a better prognosis, increased tropism to metastasize into the bones and respond to endocrine treatment options. The prognostic value of hormone receptor in urothelial carcinoma of the bladder (UCB) is less established. This may in part result from technical limitations of immunhistochemical detection methods. Interestingly, female gender has recently been identified as strong adverse factor in advanced UCB (May et al., 2011). By analyzing whole genome expression data from non-muscle invasive bladder cancer patients, we have evaluated the potential of top candidate genes (ESR1, PGR, AR, CYP19, HER2, RACGAP1) commonly used to stratify breast cancer patients to predict bladder cancer progression. In view of the gender specific effects, we have focused on the prognostic role of androgen receptor expression on tumor invasion, disease progression and survival. Methods: Affymetrix microarray data from 41 non-metastatic bladder cancer patients undergoing curative surgery were analyzed. Prognostic value of androgen receptor mRNA expression was analyzed by unsupervised Cluster analysis, partitioning tests, Mann Whitney tests and Kaplan Meier estimates of cancer specific survival. Results: Cluster analysis in the microarray date of the superficial UCB cohort identified a hormone receptor positive subtype and a proliferation dominated subtype of equal size. Androgen receptor expression was negatively associated with cancer specific death (r=−0,42; p=0,005), while proliferation correlated with increased risk of cancer specific death (r=0,46; p=0,003). In addition, low androgen receptor expression was associated with higher tumor stage (pTa vs pT1-4; p=0,017). In Kaplan Meier analysis, the cancer specific survival was significantly better in tumors exhibiting high androgen receptor levels (80% vs. 20 %; p&lt;0,0001). Discussion: Resembling to some extent the situation in other cancer types, hormone receptors are prognostic factors in early stage bladder cancer. These results may also explain the recently described gender specific effects in bladder cancer. Moreover, these results raise the possibility, that UCB patients may be stratified according to their androgen receptor status in view of prognosis and putative endocrine therapy options.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3654. doi:1538-7445.AM2012-3654

Validation of a plasma-based miRNA PCR test for early detection of colorectal cancer

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Background: Colorectal cancer (CRC) is a major cause of mortality in the western world. Early detection of CRC improves survival and screening for CRC has been clinically proven to lower CRC-related mortality in the screening population. However, although population screening programs have been implemented in a number of countries, screening rates among the 50-75 year olds are unsatisfactory. There is therefore a clear unmet need for a quick, sensitive, specific, and minimally invasive screening assay to select at risk individuals for definitive diagnosis by colonoscopy.

Methods: In order to detect microRNA (miRNA) biomarkers for CRC in blood plasma, we developed an LNA-enhanced miRNA RT-qPCR platform with high sensitivity and linearity for optimal quantitation of miRNAs from limited plasma samples. A clinical reference- lab compatible workflow that allows for the entire procedure from sample preparation through data acquisition and QC to test result to be completed within one working day was established. A reference melting curve database has been implemented to ensure the integrity of each data point, and appropriate controls monitor plate-to-plate and day-to-day variation. State-of-the-art normalization protocols have been evaluated to ensure optimal normalization of datasets prior to data analysis.

Results: We previously determined a miRNA signature in a multi hospital discovery cohort that is differentially expressed between healthy individuals and stage II CRC patients. Here we report on the validation of this miRNA signature in an independent set of plasma samples from CRC patients and healthy volunteers. We have counter-screened the miRNA signature in a set of patients with other prevalent diseases, including hypertension, diabetes, diverticulitis, and others.

Conclusions: A plasma miRNA signature for early detection of CRC from patient plasma was developed and validated in an independent clinical sample set. The signature was specific with respect to other diseases prevalent in the screening population. A second large-scale validation project is on-going. We conclude that plasma miRNA biomarkers can constitute an effective minimally invasive approach to population-wide CRC screening.

A beta-mixture model for dimensionality reduction, sample classification and analysis

Background

Patterns of genome-wide methylation vary between tissue types. For example, cancer tissue shows markedly different patterns from those of normal tissue. In this paper we propose a beta-mixture model to describe genome-wide methylation patterns based on probe data from methylation microarrays. The model takes dependencies between neighbour probe pairs into account and assumes three broad categories of methylation, low, medium and high. The model is described by 37 parameters, which reduces the dimensionality of a typical methylation microarray significantly. We used methylation microarray data from 42 colon cancer samples to assess the model.

Results

Based on data from colon cancer samples we show that our model captures genome-wide characteristics of methylation patterns. We estimate the parameters of the model and show that they vary between different tissue types. Further, for each methylation probe the posterior probability of a methylation state (low, medium or high) is calculated and the probability that the state is correctly predicted is assessed. We demonstrate that the model can be applied to classify cancer tissue types accurately and that the model provides accessible and easily interpretable data summaries.

Conclusions

We have developed a beta-mixture model for methylation microarray data. The model substantially reduces the dimensionality of the data. It can be used for further analysis, such as sample classification or to detect changes in methylation status between different samples and tissues.

Mutations in the circadian gene CLOCK in colorectal cancer

The circadian clock regulates daily variations in physiologic processes. CLOCK acts as a regulator in the circadian apparatus controlling the expression of other clock genes, including PER1. Clock genes have been implicated in cancer-related functions; in this work, we investigated CLOCK as a possible target of somatic mutations in microsatellite unstable colorectal cancers. Combining microarray gene expression data and public gene sequence information, we identified CLOCK as 1 of 790 putative novel microsatellite instability (MSI) target genes. A total of 101 MSI colorectal carcinomas (CRC) were sequenced for a coding microsatellite in CLOCK. The effect of restoring CLOCK expression was studied in LS180 cells lacking wild-type CLOCK by stably expressing GST-CLOCK or glutathione S-transferase empty vector and testing the effects of UV-induced apoptosis and radiation by DNA content analysis using flow cytometry. Putative novel CLOCK target genes were searched by using ChIP-seq. CLOCK mutations occurred in 53% of MSI CRCs. Restoring CLOCK expression in cells with biallelic CLOCK inactivation resulted in protection against UV-induced apoptosis and decreased G(2)-M arrest in response to ionizing radiation. Using ChIP-Seq, novel CLOCK-binding elements were identified near DNA damage genes p21, NBR1, BRCA1, and RAD50. CLOCK is shown to be mutated in cancer, and altered response to DNA damage provides one plausible mechanism of tumorigenesis.

Nutritional regulation of proteases involved in fetal rat insulin secretion and islet cell proliferation

Epidemiological studies have indicated that malnutrition during early life may programme chronic degenerative disease in adulthood. In an animal model of fetal malnutrition, rats received an isoenergetic, low-protein (LP) diet during gestation. This reduced fetal β-cell proliferation and insulin secretion. Supplementation during gestation with taurine prevented these alterations. Since proteases are involved in secretion and proliferation, we investigated which proteases were associated with these alterations and their restoration in fetal LP islets. Insulin secretion and proliferation of fetal control and LP islets exposed to different protease modulators were measured. Lactacystin and calpain inhibitor I, but not isovaleryl-l-carnitine, raised insulin secretion in control islets, indicating that proteasome and cysteinyl cathepsin(s), but not μ-calpain, are involved in fetal insulin secretion. Insulin secretion from LP islets responded normally to lactacystin but was insensitive to calpain inhibitor I, indicating a loss of cysteinyl cathepsin activity. Taurine supplementation prevented this by restoring the response to calpain inhibitor I. Control islet cell proliferation was reduced by calpain inhibitor I and raised by isovaleryl-l-carnitine, indicating an involvement of calpain. Calpain activity appeared to be lost in LP islets and not restored by taurine. Most modifications in the mRNA expression of cysteinyl cathepsins, calpains and calpastatin due to maternal protein restriction were consistent with reduced protease activity and were restored by taurine. Thus, maternal protein restriction affected cysteinyl cathepsins and the calpain–calpastatin system. Taurine normalised fetal LP insulin secretion by protecting cysteinyl cathepsin(s), but the restoration of LP islet cell proliferation by taurine did not implicate calpains.

Transcriptional profiling of type 1 diabetes genes on chromosome 21 in a rat beta-cell line and human pancreatic islets

We recently finemapped a type 1 diabetes (T1D)-linked region on chromosome 21, indicating that one or more T1D-linked genes exist in this region with 33 annotated genes. In the current study, we have taken a novel approach using transcriptional profiling in predicting and prioritizing the most likely candidate genes influencing beta-cell function in this region. Two array-based approaches were used, a rat insulinoma cell line (INS-1alphabeta) overexpressing pancreatic duodenum homeobox 1 (pdx-1) and treated with interleukin 1beta (IL-1beta) as well as human pancreatic islets stimulated with a mixture of cytokines. Several candidate genes with likely functional significance in T1D were identified. Genes showing differential expression in the two approaches were highly similar, supporting the role of these specific gene products in cytokine-induced beta-cell damage. These were genes involved in cytokine signaling, oxidative phosphorylation, defense responses and apoptosis. The analyses, furthermore, revealed several transcription factor binding sites shared by the differentially expressed genes and by genes demonstrating highly similar expression profiles with these genes. Comparable findings in the rat beta-cell line and human islets support the validity of the methods used and support this as a valuable approach for gene mapping and identification of genes with potential functional significance in T1D, within a region of linkage.

A genome-wide linkage search for bipolar disorder susceptibility loci in a large and complex pedigree from the eastern part of Cuba

We present results from a genome-wide scan of a six generation pedigree with 28 affected members with apparently dominant bipolar I disorder from eastern Cuba. Genotypes were obtained using the early access version of the Genechip Mapping 10K Xba array from AFFYMETRIX. Parametric and non-parametric linkage analyses under dominant and recessive models were performed using GENEHUNTER v2.1r5. Two phenotypic models were included in the analyses: bipolar I disorder and recurrent depressive disorder, or bipolar I disorder only. LOD scores were calculated for the entire family combined, and for four subdivisions of the family. For the entire family a suggestive parametric LOD score was obtained under the dominant model and the broader phenotype at 14q11.2-12 (LOD = 2.05). In the same region, a non-parametric LOD score close to genome-wide significance was also obtained, based on the entire family (NPL = 7.31, P-value = 0.07). For two individual branches of the pedigree, genome-wide significance (P < 0.005) was obtained with NPL scores of 8.71 and 12.99, respectively, also in the same region on chromosome 14. Chromosome 5q21.3-22.3 also showed close to genome-wide significant linkage for the complete pedigree (NPL = 7.26, P = 0.07), also supported by significant linkage in one individual branch (NPL = 9.86, P < 0.005). In addition, genome-wide significant nonparametric results (P-values <0.005) were obtained for individual branches at 5p13.1-q12.3, 6p22.3, 8q13.3-21.13, and 10q22.3-23.32. Finally, 2p25.1-25.3, 2p13.3-14, 3p14.2, 6p22.3-24.1, 7p14.1-14.2, 8q12.2-12.3, 10q21.1-21.2, 14q13.1-21.1, 15q15.1-21.2, and 22q12.3-13.32 showed suggestive linkage in the complete family. Most of these potential susceptibility loci overlap with, or are close, to previous linkage findings. The locus on 5q may, however, represent a novel susceptibility locus.

Retinoblastoma pathway defects show differential ability to activate the constitutive DNA damage response in human tumorigenesis

Loss of G(1)-S control and aberrations of the p16(Ink4a)-cyclin D1/cyclin-dependent kinase (CDK) 4(6)-pRb-E2F-cyclin E/CDK2 pathway are common in human cancer. Previous studies showed that oncogene-induced aberrant proliferation, such as on cyclin E overexpression, causes DNA damage and checkpoint activation. Here, we show that, in a series of human colorectal adenomas, those with deregulation of cyclin D1 and/or p16(Ink4a) showed little evidence of constitutive DNA damage response (DDR), contrary to cyclin E-overexpressing higher-grade cases. These observations were consistent with diverse cell culture models with differential defects of retinoblastoma pathway components, as overexpression of cyclin D1 or lack of p16(Ink4a), either alone or combined, did not elicit detectable DDR. In contrast, inactivation of pRb, the key component of the pathway, activated the DDR in cultured human or mouse cells, analogous to elevated cyclin E. These results highlight differential effect of diverse oncogenic events on driving the 'cancer cell cycles' and their ability to deregulate the replication-driving CDK2 kinase and to alarm the DDR as a potential anticancer barrier in accordance with their hierarchical positions along the retinoblastoma pathway. Our data provide new insights into oncogene-evoked DDR in human tumorigenesis, with potential implications for individualized management of tumors with elevated cyclin D1 versus cyclin E, due to their distinct clinical variables and biological behavior.

Are microRNAs located in genomic regions associated with cancer?

We report on the location of 283 miRNAs in the human genome in relation to copy number changes in three distinct types of tumours: prostate, bladder and colon. In prostate and colon tumours, we find miRNAs over-represented in regions with copy number gain and under-represented in regions with copy number loss. Surprisingly this pattern appears to be reversed in bladder cancer. We compared our miRNA copy number data to published miRNA expression data; unexpectedly, we did not find a statistically significant relationship between miRNA copy number and expression level. This suggests that miRNA expression is regulated through different mechanisms than mRNA expression.

Prevention of hyperglycemia in Zucker diabetic fatty rats by exercise training: effects on gene expression in insulin-sensitive tissues determined by high-density oligonucleotide microarray analysis

Exercise training (ET) causes metabolic improvement in the prediabetic and diabetic states. However, only little information exists on the changes to ET at the transcriptional level in insulin-sensitive tissues. We have investigated the gene expression changes in skeletal muscle, liver, fat, and pancreatic islets after ET in male Zucker diabetic fatty (ZDF) rats. Eighteen ZDF rats (7 weeks old) were divided in a control and ET group. Exercise was performed using a motorized treadmill (20 m/min 1 hour daily for 6 days a week). Blood glucose, weight, and food intake were measured weekly. After 5 weeks, blood samples, soleus muscle, liver, visceral fat (epididymal fat pads), and islet tissue were collected. Gene expression was quantified with Affymetrix RG-U34A array (16 chips). Exercise training ameliorates the development of hyperglycemia and reduces plasma free fatty acid and the level of glucagon-insulin ratio (P < .05). In skeletal muscle, the expression of 302 genes increased, whereas that of 119 genes decreased. These changes involved genes related to skeletal muscle plasticity, Ca(2+) signals, energy metabolism (eg, glucose transporter 1, phosphorylase kinase), and other signaling pathways as well as genes with unknown functions (expressed sequence tags). In the liver, expression of 148 genes increased, whereas that of 199 genes decreased. These were primarily genes involved in lipogenesis and detoxification. Genes coding for transcription factors were changed in parallel in skeletal muscle and liver tissue. Training did not markedly influence the gene expression in islets. In conclusion, ET changes the expression of multiple genes in the soleus muscle and liver tissue and counteracts the development of diabetes, indicating that ET-induced changes in gene transcription may play an important role en the prevention of diabetes.

Cellular differentiation hierarchies in normal and culture-adapted human embryonic stem cells

Human embryonic stem cell (HESC) lines vary in their characteristics and behaviour not only because they are derived from genetically outbred populations, but also because they may undergo progressive adaptation upon long-term culture in vitro. Such adaptation may reflect selection of variants with altered propensity for survival and retention of an undifferentiated phenotype. Elucidating the mechanisms involved will be important for understanding normal self-renewal and commitment to differentiation and for validating the safety of HESC-based therapy. We have investigated this process of adaptation at the cellular and molecular levels through a comparison of early passage (normal) and late passage (adapted) sublines of a single HESC line, H7. To account for spontaneous differentiation that occurs in HESC cultures, we sorted cells for SSEA3, which marks undifferentiated HESC. We show that the gene expression programmes of the adapted cells partially reflected their aberrant karyotype, but also resulted from a failure in X-inactivation, emphasizing the importance in adaptation of karyotypically silent epigenetic changes. On the basis of growth potential, ability to re-initiate ES cultures and global transcription profiles, we propose a cellular differentiation hierarchy for maintenance cultures of HESC: normal SSEA3+ cells represent pluripotent stem cells. Normal SSEA3- cells have exited this compartment, but retain multilineage differentiation potential. However, adapted SSEA3+ and SSEA3- cells co-segregate within the stem cell territory, implying that adaptation reflects an alteration in the balance between self-renewal and differentiation. As this balance is also an essential feature of cancer, the mechanisms of culture adaptation may mirror those of oncogenesis and tumour progression.

Presymptomatic diagnosis using a deletion of a single codon in families with hereditary non-polyposis colorectal cancer

The diagnosis of hereditary non-polyposis colorectal cancer (HNPCC) is often confirmed by a mutation in one of several mismatch-repair genes, in particular MLH1, MSH2 and MSH6. Presymptomatic diagnosis requires the identification of a mutation causing the disease. Three different deletions of a single amino acid codon have previously been published as assumed pathogenic. The objective of this study was to determine if an MSH2 3 base pair in-frame deletion (N596del) could be used in presymptomatic screening of at-risk individuals. We report on five HNPCC families with the N596del mutation, identified after mutation screening of MSH2 and MLH1. All patients in the families were haplotyped using markers flanking the MSH2 gene. The haplotypes revealed that the five families with high probability descended from only two founders. The N596del segregated with the HNPCC phenotype with lod scores of 3.2 and 2.0 at the recombination fraction of 0.0 in the two founder families. Sequencing of MSH2 and MLH1 did not reveal other pathogenic mutations, and N596del was not identified in 50 healthy controls. The mutation has previously been found expressed in mRNA, and is located in a conserved domain. The results support the hypothesis that N596del is the disease causing mutation and not a clinically silent variation. On this basis, the application of the MSH2 N596del mutation, in presymptomatic screening of HNPCC families, is recommended.

The RET/PTC-RAS-BRAF linear signaling cascade mediates the motile and mitogenic phenotype of thyroid cancer cells

In papillary thyroid carcinomas (PTCs), rearrangements of the RET receptor (RET/PTC) and activating mutations in the BRAF or RAS oncogenes are mutually exclusive. Here we show that the 3 proteins function along a linear oncogenic signaling cascade in which RET/PTC induces RAS-dependent BRAF activation and RAS- and BRAF-dependent ERK activation. Adoptive activation of the RET/PTC-RAS-BRAF axis induced cell proliferation and Matrigel invasion of thyroid follicular cells. Gene expression profiling revealed that the 3 oncogenes activate a common transcriptional program in thyroid cells that includes upregulation of the CXCL1 and CXCL10 chemokines, which in turn stimulate proliferation and invasion. Thus, motile and mitogenic properties are intrinsic to transformed thyroid cells and are governed by an epistatic oncogenic signaling cascade.

Gene expression profiles during beta cell maturation and after IL-1beta exposure reveal important roles of Pdx-1 and Nkx6.1 for IL-1beta sensitivity

AIM/HYPOTHESIS

Maturation of the beta cells in the islets of Langerhans is dependent upon sequential activation of different transcription factors such as Pdx-1 and Nkx6.1. This maturation is associated with an acquired sensitivity to cytokines and may eventually lead to type 1 diabetes. The aims of this study were to characterise changes in mRNA expression during beta cell maturation as well as after interleukin-1beta (IL-1beta) exposure.

METHODS

Transcriptome analyses were performed on two phenotypes characterised as a glucagon-producing pre-beta-cell phenotype (NHI-glu), which matures to an IL-1beta-sensitive insulin-producing beta cell phenotype (NHI-ins). Beta cell lines over-expressing Pdx-1 or Nkx6.1, respectively, were used for functional characterisation of acquired IL-1beta sensitivity.

RESULTS

During beta cell maturation 98 fully annotated mRNAs changed expression levels. Of these, 50 were also changed after 24 h of IL-1beta exposure. In addition, 522 and 197 fully annotated mRNAs, not affected by maturation, also changed expression levels following IL-1beta exposure of the beta cell and the pre-beta-cell phenotype, respectively. Beta cell maturation was associated with an increased expression of Nkx6.1, whereas both Pdx-1 and Nkx6.1 expression were decreased following IL-1beta exposure. Over-expression of Nkx6.1 or Pdx-1 in cell lines resulted in a significantly increased sensitivity to IL-1beta.

CONCLUSIONS/INTERPRETATION

These results suggest that the final beta cell maturation accompanied by increased IL-1beta sensitivity is, in part, dependent upon the expression of genes regulated by Pdx-1 and Nkx6.1. Future classification of the genes regulated by these transcription factors and changed during beta cell maturation should elucidate their role in the acquired sensitivity to IL-1beta and may be helpful in identifying new targets for intervention/prevention strategies.

Functional expression of the CXCR4 chemokine receptor is induced by RET/PTC oncogenes and is a common event in human papillary thyroid carcinomas

To identify genes involved in the transformation of thyroid follicular cells, we explored, using DNA oligonucleotide microarrays, the transcriptional response of PC Cl3 rat thyroid epithelial cells to the ectopic expression of the RET/PTC oncogenes. We found that RET/PTC was able to induce the expression of CXCR4, the receptor for the chemokine CXCL12/SDF-1alpha/beta. We observed that CXCR4 expression correlated with the transforming ability of the oncoprotein and depended on the integrity of the RET/PTC-RAS/ERK signaling pathway. We found that CXCR4 was expressed in RET/PTC-positive human thyroid cancer cell lines, but not in normal thyroid cells. Furthermore, we found CXCR4 expression in human thyroid carcinomas, but not in normal thyroid samples by immunohistochemistry. Since CXCR4 has been recently implicated in tumor proliferation, motility and invasiveness, we asked whether treatment with SDF-1alpha was able to induce a biological response in thyroid cells. We observed that SDF-1alpha induced S-phase entry and survival of thyroid cells. Invasion through a reconstituted extracellular matrix was also supported by SDF-1alpha and inhibited by a blocking antibody to CXCR4. Taken together, these results suggest that human thyroid cancers bearing RET/PTC rearrangements may use the CXCR4/SDF-1alpha receptor-ligand pathway to proliferate, survive and migrate.

Gene microarray study corroborates proteomic findings in rodent islet cells

As reported in an issue of Journal of Proteome Research, mass spectrometry has been used to identify numerous proteins in pancreatic islets. Our group studies beta cell gene expression, and we were interested in whether proteins described in this study could be found at the level of the transcriptome. Microarray analysis is a powerful technique for quantitative measurements of the expression of thousand genes in parallel. However, in crude tumor biopsies, only a subset of transcripts correlate with protein levels, and it is still unknown how frequently mRNA expression correlates with amount of protein in well-differentiated cells. To address this issue, we presently compared data from mouse primary islet proteins obtained by proteomic analysis with RNA data from FACS purified primary rat beta cells obtained by microarray analysis (Rasschaert J, Liu D, Cardozo AK, Kutlu B, Eizirik DL, manuscript in preparation).

Plasticity in the adult rat pancreas: transdifferentiation of exocrine to hepatocyte-like cells in primary culture

Under certain experimental conditions, hepatocytes can arise in the pancreas. It has been suggested that the pancreas retains a source of hepatocyte progenitor cells. However, such cells have not been yet identified in the adult pancreas. We describe here the transdifferentiation of primary rat pancreatic exocrine cells into hepatocyte-like cells during 5 days of tissue culture in the presence of dexamethasone (DX). Using reverse-transcription polymerase chain reaction and immunocytochemistry, it was observed that DX treatment induced albumin RNA and protein expression in the cells. Coexpression of albumin and amylase, and the absence of cell proliferation, demonstrated a direct transdifferentiation of acinar cells to hepatocytic cells. CCAAT enhancer-binding protein-ss protein, a liver-enriched transcription factor that is considered to be the master switch in pancreatohepatic transdifferentiation, and alpha-fetoprotein were markedly upregulated in the cells after treatment with DX. We compared transcriptional profiles of freshly isolated exocrine cells and DX-treated cells using oligonucleotide microarrays and found that multiple liver-specific genes are induced along with albumin, and that certain pancreatic genes are downregulated in the DX-treated cells. In conclusion, these observations support the notion of plasticity in the adult pancreas and that exocrine cells can be reprogrammed to transdifferentiate into other cell types such as hepatocytes.

The reliability of immunohistochemistry as a prescreening method for the diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC)--results of an international collaborative study

Hereditary nonpolyposis colorectal cancer syndrome (HNPCC) is an autosomal dominant condition accounting for 2-5% of all colorectal carcinomas as well as a small subset of endometrial, upper urinary tract and other gastrointestinal cancers. An assay to detect the underlying defect in HNPCC, inactivation of a DNA mismatch repair enzyme, would be useful in identifying HNPCC probands. Monoclonal antibodies against hMLH1 and hMSH2, two DNA mismatch repair proteins which account for most HNPCC cancers, are commercially available. This study sought to investigate the potential utility of these antibodies in determining the expression status of these proteins in paraffin-embedded formalin-fixed tissue and to identify key technical protocol components associated with successful staining. A set of 20 colorectal carcinoma cases of known hMLH1 and hMSH2 mutation and expression status underwent immunoperoxidase staining at multiple institutions, each of which used their own technical protocol. Staining for hMSH2 was successful in most laboratories while staining for hMLH1 proved problematic in multiple labs. However, a significant minority of laboratories demonstrated excellent results including high discriminatory power with both monoclonal antibodies. These laboratories appropriately identified hMLH1 or hMSH2 inactivation with high sensitivity and specificity. The key protocol point associated with successful staining was an antigen retrieval step involving heat treatment and either EDTA or citrate buffer. This study demonstrates the potential utility of immunohistochemistry in detecting HNPCC probands and identifies key technical components for successful staining.

Antihyperglycemic and blood pressure-reducing effects of stevioside in the diabetic Goto-Kakizaki rat

Stevioside, a glycoside present in the leaves of the plant, Stevia rebaudiana Bertoni (SrB), has acute insulinotropic effects in vitro. Its potential antihyperglycemic and blood pressure-lowering effects were examined in a long-term study in the type 2 diabetic Goto-Kakizaki (GK) rat. Rats were fed 0.025 g x kg(-1) x d(-1) of stevioside (purity > 99.6%) for 6 weeks. An intra-arterial catheter was inserted into the rats after 5 weeks, and conscious rats were subjected to arterial glucose tolerance test (2.0 g x kg(-1)) during week 6. Stevioside had an antihyperglycemic effect (incremental area under the glucose response curve [IAUC]): 985 +/- 20 (stevioside) versus 1,575 +/- 21 (control) mmol/L x 180 minutes, (P <.05), it enhanced the first-phase insulin response (IAUC: 343 +/- 33 [stevioside] v 136 +/- 24 [control] microU/mL insulin x 30 minutes, P <.05) and concomitantly suppressed the glucagon levels (total AUC: 2,026 +/- 234 [stevioside] v 3,535 +/- 282 [control] pg/mL x 180 minutes, P <.05). In addition, stevioside caused a pronounced suppression of both the systolic (135 +/- 2 v 153 +/- 5 mm Hg; P <.001) and the diastolic blood pressure (74 +/- 1 v 83 +/- 1 mm Hg; P <.001). Bolus injections of stevioside (0.025 g x kg(-1)) did not induce hypoglycemia. Stevioside augmented the insulin content in the beta-cell line, INS-1. Stevioside may increase the insulin secretion, in part, by induction of genes involved in glycolysis. It may also improve the nutrient-sensing mechanisms, increase cytosolic long-chain fatty acyl-coenzyme A (CoA), and downregulate phosphodiesterase 1 (PDE1) estimated by the microarray gene chip technology. In conclusion, stevioside enjoys a dual positive effect by acting as an antihyperglycemic and a blood pressure-lowering substance; effects that may have therapeutic potential in the treatment of type 2 diabetes and the metabolic syndrome.

Critical role for cataplerosis via citrate in glucose-regulated insulin release

The molecular mechanisms mediating acute regulation of insulin release by glucose are partially known. The process involves at least two pathways that can be discriminated on basis of their (in)dependence of closure of ATP-sensitive potassium (K+(ATP)) channels. The mechanism of the K+(ATP) channel-independent pathway was proposed to involve cataplerosis, the export of mitochondrial intermediates into the cytosol and in the induction of fatty acid-derived signaling molecules. In the present article, we have explored in fluorescence-activated cell sorter (FACS)-purified rat beta-cells the molecular steps involved in chronic glucose regulation of the insulin secretory response. When compared with culture in 10 mmol/l glucose, 24 h culture in 3 mmol/l glucose shifts the phenotype of the cells into a state with low further secretory responsiveness to glucose, lower rates of glucose oxidation, and lower rates of cataplerosis. Microarray mRNA analysis indicates that this shift can be attributed to differences in expression of genes involved in the K+(ATP) channel-dependent pathway, in cataplerosis and in fatty acid/cholesterol biosynthesis. This response was paralleled by glucose upregulation of the transcription factor sterol regulatory element binding protein 1c (SREBP1c) (ADD1) and downregulation of peroxisome proliferator-activated receptor (PPAR)-alpha and PPAR-beta (PPARdelta). The functional importance of cataplerosis via citrate for glucose-induced insulin release was further supported by the observation that two ATP-citrate lyase inhibitors, radicicol and (-)-hydroxycitrate, block part of glucose-stimulated release in beta-cells. In conclusion, chronic glucose regulation of the glucose-responsive secretory phenotype is associated with coordinated changes in gene expression involved in the K+(ATP) channel-dependent pathway, in cataplerosis via citrate and in acyl CoA/cholesterol biosynthesis.

Identification of an IMPDH1 mutation in autosomal dominant retinitis pigmentosa (RP10) revealed following comparative microarray analysis of transcripts derived from retinas of wild-type and Rho(-/-) mice

Comparative analysis of the transcriptional profiles of approximately 6000 genes in the retinas of wild-type mice with those carrying a targeted disruption of the rhodopsin gene was undertaken by microarray analysis. This revealed a series of transcripts, of which some were derived from genes known to map at retinopathy loci, levels of which were reduced or elevated in the retinas of Rho(-/-) mice lacking functional photoreceptors. The human homologue of one of these genes, encoding inosine monophosphate dehydrogenase type 1 (IMPDH1), maps to the region of 7q to which an adRP gene (RP10) had previously been localized. Mutational screening of DNA from the Spanish adRP family, originally used to localize the RP10 gene, revealed an Arg224Pro substitution co-segregating with the disease phenotype. The amino acid at position 224 of the IMPDH1 protein is conserved among species and the substitution is not present in healthy, unrelated individuals of European origin. These data provide strong evidence that mutations within the IMPDH1 gene cause adRP, and validate approaches to mutation detection involving comparative analysis of global transcription profiles in normal and degenerating retinal tissues. Other genes showing significant alterations in expression include some with anti-apoptotic functions and many encoding components of the extracellular matrix or cytoskeleton, a possible reflection of a response by Muller cells to preserve the remaining outer nuclear layer of the retina. We suggest that those genes identified are prime candidates for etiological involvement in degenerative retinal disease.

Identification of novel cytokine-induced genes in pancreatic beta-cells by high-density oligonucleotide arrays

Type 1 diabetes is an autoimmune disease resulting from the selective destruction of insulin-producing beta-cells. Cytokines may contribute to pancreatic beta-cell death in type 1 diabetes. beta-cell exposure to interleukin (IL)-1beta induces functional impairment, whereas beta-cell culture for 6-9 days in the presence of IL-1beta and interferon (INF)-gamma leads to apoptosis. To clarify the mechanisms involved in these effects of cytokines, we studied the general pattern of cytokine-induced gene expression in beta-cells. Primary rat beta-cells were fluorescence-activated cell sorter-purified and exposed for 6 or 24 h to control condition, IL-1beta + INF-gamma, or IL-1beta alone (24 h only). Gene expression profile was analyzed in duplicate by oligonucleotide arrays. Nearly 3,000 transcripts were detected in controls and cytokine-treated beta-cells. Of these, 96 and 147 displayed changes in expression after 6 and 24 h, respectively, of exposure to IL-1beta + INF-gamma, whereas 105 transcripts were modified after a 24-h exposure to IL-1beta. The cytokine-responsive genes were clustered according to their biological functions. The major clusters observed were metabolism, signal transduction, transcription factors, protein synthesis/ processing, hormones, and related receptors. These modifications in gene expression may explain some of the cytokine effects in beta-cells, such as decreased protein biosynthesis and insulin release. In addition, there was induction of diverse cytokines and chemokines; this suggests that beta-cells may contribute to mononuclear cell homing during insulitis. Several of the cytokine-induced genes are potentially regulated by the transcription factor NF-kappaB. Clarification of the function of the identified cytokine-induced gene patterns may unveil some of the mechanisms involved in beta-cell damage and repair in type 1 diabetes.

Loss of heterozygosity at 1p, 8p, 10p, 13q, and 17p in advanced urothelial cancer and lack of relation to chemotherapy response and outcome

Studies of urothelial tumors have identified structural abnormalities in a number of chromosomes. This study aimed to identify specific genetic changes of patients with advanced urothelial cancers, and relate these changes to increased chemotherapy sensitivity or good prognosis. We screened 56 muscle-invasive bladder cancer tumors for loss of heterozygosity (LOH) at chromosome 1p, 8p, 10p, 13q, and 17p with PCR using 6 microsatellite markers. All patients had recurrent locally advanced or metastatic disease. DNA was extracted after microdissection of the primary tumor and normal tissue from paraffin-embedded specimens. The PCR products were electrophoresed in an ABI Prism 377 DNA sequencer and the alleles from tumor DNA and normal tissue DNA were analyzed using the GeneScan program. The LOH findings were correlated with response to chemotherapy and survival. Allelic loss of specific markers was present in 26-50% of the informative tumors. The most frequent LOH was observed at 17p, supporting the notion that this region may contain genes of importance to urothelial cancer progression. The overall rate of response to chemotherapy was 48%, and ranged from 40% to 56% according to specific LOH changes. The median survival of all patients from start of chemotherapy was 5.8 months and ranged from 5.3 to 7.9 months for patients with specific LOH changes. Response and survival of patients with no lost markers was the same size, compared to patients with one, two, or more lost markers. Specific genetic changes were detected in a significant number of tumors from patients with advanced urothelial cancer. These changes were not predictive of response to chemotherapy or of the duration of survival.

Expression of transforming growth factor alpha and epidermal growth factor receptor in human bladder cancer

We analysed the expression of epidermal growth factor receptor (EGFr) and transforming growth factor alpha (TGF-alpha) in human bladder tumours. Tumour biopsies were obtained from 54 patients with primary bladder cancer (18 stage T1 and 36 stage T2-4). The protein and mRNA expression of EGFr and TGF-alpha were quantified by ELISA and competitive RT-PCR, respectively. The EGFr protein level was significantly increased in T2-4 tumours (0.44 x 10(-11); 0.0-27.5 x 10(-11) mol/g) compared with T1 tumours (0.0; 0.0-2.0 x 10(-11) mol/g) (median; range; 2p<0.01). The EGFr protein and mRNA level correlated (Spearman r=0.45, 2p<0.005, n=40). Co-expression of TGF-alpha protein and EGFr protein was significantly associated with muscle invasive tumours (T2-4) (chi-squared=7.9, df=3, p<0.05) and the TGF-alpha protein level correlated significantly with EGFr protein expression (Spearman r=0.56, 2p<0.0001, n=54). While tumour stage correlated with survival, no correlation was observed between survival and the expression of EGFr and/or TGF-alpha. In conclusion, human bladder tumours express both EGFr and TGF-alpha. The expression of EGFr and TGF-alpha are closely correlated, and the expression of EGFr and co-expression of EGFr and TGF-alpha correlate with tumour stage.

Short-term culturing of low-grade superficial bladder transitional cell carcinomas leads to changes in the expression levels of several proteins involved in key cellular activities

Fresh, superficial transitional cell carcinomas (TCCs) of low-grade atypia (3 grade I, Ta; 6 grade II, Ta), as well as primary cultures derived from them were labeled with [35S]methionine for 16 h, between 2 and 6 days after inoculation. Whole protein extracts were subjected to IEF (isoelectric focusing) two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) followed by autoradiography. Proteins were identified by a combination of proteomic technologies that included microsequencing, mass spectrometry, 2-D PAGE immunoblotting and comparison with the bladder TCC protein database available on the internet (http://biobase.dk/cgi-bin/celis). Comparison of the IEF 2-D gel protein profiles of fresh tumors and their primary cultures showed that the overall expression profiles were strikingly similar, although differing significantly in the levels of several proteins whose rate of synthesis was differentially regulated in at least 85% of the tumor/culture pairs as a result of the short-term culturing. Most of the proteins affected by culturing were upregulated and among them we identified components of the cytoskeleton (keratin 18, gelsolin and tropomyosin 3), a molecular chaperone (hsp 28), aldose reductase, GST pi, metastasin, synuclein, the calreticulin precursor and three polypeptides of unknown identity. Only four major proteins were downregulated, and these included two fatty acid-binding proteins (FABP:FABP5 and A-FABP) which are thought to play a role in growth control, the differentiation-associated keratin 20, and the calcium-binding protein annexin V. Proteins that were differentially regulated in only some of the cultured tumors included alpha-enolase, triosphosphate isomerase, members of the 14-3-3 family, hnRNPs F and H, PGDH, hsp (heat-shock protein) 60, BIP, the interleukin-1 receptor antagonist, the nucleolar protein B23, as well as several proteins of yet unknown identity. The suitability of in vitro bladder tumor culture models to study complex biological phenomena such as malignancy and invasion is discussed.

Improved laboratory test selection and enhanced perception of test results as tools for cost-effective medicine

Inconsistencies in the way physicians perceive and handle identical laboratory results have untoward effects on morbidity, mortality and cost of medical care. In this context, the selection of suitable tests to answer definite clinical questions, and the manner in which laboratory results are presented have great impact on the action taken by the clinician. This review addresses preferred methods to improve laboratory test selection, and examines methods that more effectively convey laboratory results to clinicians. It is anticipated that refined selection of tests, and presentation of the test results in a configuration that is easily perceived by the clinician, will facilitate interpretation of laboratory reports. Furthermore, any measures that promote the application of laboratory information in medical practice improve economics at the laboratory-clinical interface. The presently described methods to optimize test selection and interpretation are: likelihood ratios to provide estimates of the ability of a test to identify a clinical condition; consensus- and discriminant function-analysis to estimate the performance of tests in diagnosing a particular disease or condition; receiver operating characteristic (ROC) curves to assess discrimination capabilities. The methods which improve test result perception are expression of results as multiples of the upper normal limit, utilizing signal strength to provide prognostic probabilities, and presentation of results in graphic forms that display mutually interrelated functions, with a specific cluster of results being highly suggestive of a given condition. In addition, we discuss application of expert systems to provide rules based on knowledge and experience to analyze results of tests and suggest diagnosis and action, including additional tests when required. It is anticipated that judicious utilization of laboratory services by application of the reviewed methodologies will help to achieve medically justified responses at a lower cost and help to achieve a proper balance between cost of tests and their clinical usefulness.

Chronic treatment with epidermal growth factor stimulates growth of the urinary tract in the rat

Twenty-four male Wistar rats, 8 weeks old, were allocated into three groups and treated with human recombinant epidermal growth factor (EGF) administered subcutaneously in doses of 0, 30, and 150 micrograms/kg per day for 4 weeks. Blood sampling was done every 2nd week and urine sampling was done for 2 consecutive days every week. The most striking finding was that the ureters were dose dependently enlarged, due to growth of all layers of the ureteric wall. The urothelium of the bladder showed considerable hyperplasticity with a widening of the basal proliferative compartment and a normal differentiation pattern as observed by the expression of carbohydrate epitopes, characterized with lectinohistochemistry. Blood examination revealed a decrease in blood haemoglobin concentration and a slight increase in serum creatinine concentration in the high-dose group. There were no effects of EGF on the urinary excretion of electrolytes, proteins, and endogenous EGF.

Characterization of carbohydrates in the alpha 2-macroglobulin receptor

Carbohydrates were characterized in the human placental alpha 2-macroglobulin receptor and its associated protein. Carbohydrates, largely N-linked, contributed to about 18% of the size of the receptor alpha-chain and to about 25% of the beta-chain. The 40 kDa receptor-associated protein also contained carbohydrate. The alpha- and beta-chains contained a wide variety of carbohydrates as judged by binding of lectins. Monosaccharide-competing inhibition of alpha 2M-methylamine binding by WGA suggested a functional significance of sugars in binding of ligands to the alpha-chain.

Stereologic estimates of nuclear volume in noninvasive bladder tumors (Ta) correlated with the recurrence pattern

The mean nuclear volume of cells in bladder tumors was estimated using the principle for estimation of the volume of particles of arbitrary shape. The study included three groups of patients: one group of 10 patients with only one nonrecurrent, noninvasive bladder tumor (Ta), another group of 11 patients with recurrent noninvasive bladder tumors, and a third group of 14 patients with recurrent primary noninvasive bladder tumors who ultimately developed an invasive tumor. After standard fixation, embedding, sectioning, and hematoxylin-eosin staining an unbiased estimate of the mean volume of nuclei sampled with a chance proportional to their volume was calculated: nu v = pi/3.l3(0). Here lo is the length of the intercept through a test point hitting a nucleus measured in a random direction through the test point. In the primary tumor the mean, nuclear volume of the cells in tumors from patients with a single bladder tumor is small (141 micrograms 3 geometric mean) with only one of ten above 165 microns 3. The mean nuclear volume of the primary tumor cells in patients with recurrent noninvasive bladder tumors was slightly larger (195 microns 3 geometric mean) with five of 11 above 165 microns 3. The mean nuclear volume of the primary tumor cells in patients who ended up with invasive tumors was higher (245 microns 3 geometric mean) with 12 of 14 above 165 microns 3. A large mean nuclear volume of cells in noninvasive bladder tumors (Ta) indicates recurrence and an invasive potential. Considering that nearly all primary tumors were classified as Bergkvist Grade II tumors, the prognostic precision of absolute mean nuclear volume is noticeable. This simple and fast estimate of mean nuclear volume seems to provide objective data with high prognostic value in primary noninvasive bladder tumors (Ta).

A comparison between stereological estimates of mean nuclear volume and DNA flow cytometry in bladder tumours

The correlation between stereological estimate of mean nuclear volume and DNA-content was studied in 55 human urinary bladder tumours. The DNA-content was determined by flow cytometry on isolated nuclei stained with ethidium bromide. Trout erythrocytes were used as a biological internal standard providing an accurate determination of the DNA-histogram. An unbiased estimate of the mean nuclear volume (vv) was obtained after standard formaline fixation, paraffin-embedding, sectioning and hematoxylin-eosin staining using the equation vv = pi/3.l3(0). Here l0 is the length of an intercept measured in a random direction through a test point, which hit a nucleus. A highly significant correlation was found between vv and mean DNA-content of nuclei (2p = 0.0004). A highly significant correlation was also found between vv and the highest DNA-content present in tumours having cell populations with different DNA content (2p = 0.0016). The mean nuclear volume and the DNA-content also correlated well with the pathologic grade. Although significant the correlations were far from perfect, which indicates that DNA content and mean nuclear volume may provide partly independent biological information. The methods provide objective, unbiased and reproducible data which may improve the possibility of grading and predicting the disease course of human urinary bladder tumours.

Semiquantitative oestrogen receptor assay in formalin-fixed paraffin sections of human breast cancer tissue using monoclonal antibodies

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Plasma fibronectin in acute myeloid leukaemia

In 13 patients with acute myeloid leukaemia (AML), plasma fibronectin (P-FN) was measured before, during and after chemotherapy. Pre-treatment concentrations of P-FN were within the reference range and significantly higher than the nadir value (p less than 0.05). A rise in body temperature by more than 1 degree C induced a significant fall in P-FN (p less than 0.05) and transfusion with freshly drawn blood products could prevent this fall. P-FN concentrations were significantly higher in patients obtaining complete haematological remission than in patients in whom remission could not be induced (p less than 0.001). This difference could not be attributed to transfusion or febrile episodes.

Oestrogen receptor assay. False positive analysis?

The influence of unlabelled oestradiol, DES, testosterone and R-5020/org 2058 on tritiated oestradiol binding was investigated in 162 ER positive cases of patients with primary breast carcinoma. A dextran-coated charcoal as well as a sucrose gradient method was applied. In 122 cases only unlabelled oestradiol and DES significantly displaced the binding of labelled oestradiol. In the remaining 40 cases, oestradiol, DES, as well as testosterone and R-5020/org 2058 were able to displace the high-affinity, saturable binding of tritiated oestradiol equally. Possible explanations of this new discovery are discussed.