Accumulation of small hyaluronan oligosaccharides in tumour interstitial fluid correlates with lymphatic invasion and lymph node metastasis.

BACKGROUND: Association studies have implicated the glycosaminoglycan hyaluronan (hyaluronic acid, HA) and its degrading enzymes the hyaluronidases in tumour progression and metastasis. Oligosaccharides of degraded HA have been ascribed a number of biological functions that are not exerted by high-molecular-weight HA (HMW-HA). However, whether these small HA oligosaccharides (sHA) have a role in tumour progression currently remains uncertain due to an inability to analyse their concentration in tumours. METHODS: We report a novel method to determine the concentration of sHA ranging from 6 to 25 disaccharides in tumour interstitial fluid (TIF). Levels of sHA were measured in TIF from experimental rat tumours and human colorectal tumours. RESULTS: While the majority of HA in TIF is HMW-HA, concentrations of sHA up to 6 µg ml(-1) were detected in a subset of tumours, but not in interstitial fluid from healthy tissues. In a cohort of 72 colorectal cancer patients we found that increased sHA concentrations in TIF are associated with lymphatic vessel invasion by tumour cells and the formation of lymph node metastasis. CONCLUSIONS: These data document for the first time the pathophysiological concentration of sHA in tumours, and provide evidence of a role for sHA in tumour progression.

COX-2, TFF1, and Src define better prognosis in young patients with gastric cancer.

BACKGROUND AND OBJECTIVES: Despite its dwindling occurrence, gastric cancer remains a leading cause of cancer related mortality worldwide. Molecular determinants of prognosis that impact survival are being sought out as a means to facilitate rational clinical decision-making and enhance patient management. In this study, we evaluated three molecules implicated in gastric carcinogenesis and demonstrated that the differential expression of cyclooxygenase-2 (COX-2) and the viral oncogene homolog Src proteins could explain the differences in survival observed in patients older and younger than 50 years of age. METHODS: We evaluated 5-year survival in a cohort of 423 gastric cancer patients using chronological age as a variable. Additionally, we assessed the protein expression of three molecules (COX-2, TFF1, Src) implicated in the pathogenesis of gastric cancer using immunohistochemistry. RESULTS: We found that patients younger than 50 years of age had a better 5-year survival rate in all tumor stages. We found that the expression of COX-2 and Src correlated significantly with survival in this group without any significant impact attributable to TFF1. CONCLUSIONS: Our study demonstrates that young gastric cancer patients have a better prognostic outlook that could in part be explained by the differential expression of COX-2 and Src.

Endorectal ultrasound and real-time elastography in patients with fecal incontinence following anorectal surgery: a prospective comparison evaluating short- and long-term outcomes in irradiated and non-irradiated patients.

BACKGROUND AND AIMS: Transanal real-time elastography (RTE) was demonstrated to yield valuable information regarding elastic properties of the anal sphincter in patients with fecal incontinence. We studied the role of RTE findings as a risk factor for the outcome of patients with fecal incontinence following anorectal surgery in irradiated and non-irradiated individuals and compared these observations with conventional B-mode/color Doppler EUS.  PATIENTS AND METHODS: 90 patients with postsurgical fecal incontinence were included in this prospective monocentric study. Baseline and follow-up (after 3 weeks and 1 year) assessment included an incontinence severity score questionnaire, rectal manometry, B-mode/color Doppler EUS and RTE with quantitation of the sphincter elastograms. RESULTS: 81 patients could be finally assessed, in 24 patients (29.6%) a pathological elastogram with predominantly hard elements was found; logistic regression analysis revealed no significant association with the short- and long-term clinical outcome nor were any differences seen between irradiated and non-irradiated patients. Defined sphincter defects as seen with conventional EUS were significanntly associated with a worse short- and long-term outcome: odds ratio ORshort-term: 1.414 (1.107 - 1.807, p = 0.0101); ORlong-term: 1.675 (95% CI: 1.133 - 2.477; p = 0.0294). Submucosal thickening and hypervascularization were found more frequently in the irradiated group (p < 0.01). CONCLUSION: RTE with quantitation of sphincter elastic properties yields no further diagnostic and prognostic information compared to conventional EUS in irradiated and non-irradiated patients and, therefore, cannot be regarded as a new tool in the assessment of those patients. Our data further confirm the view that defined sphincter defects may be a major risk factor for an unfavorable outcome.

Individual development and uPA-receptor expression of disseminated tumour cells in bone marrow: a reference to early systemic disease in solid cancer.

It is unclear whether disseminated tumour cells detected in bone marrow in early stages of solid cancers indicate a subclinical systemic disease component determining the patient's fate or simply represent mainly irrelevant shed cells. Moreover, characteristics differentiating high and low metastatic potential of disseminated tumour cells are not defined. We performed repeated serial bone marrow biopsies during follow-up in operated gastric cancer patients. Most patients with later tumour relapse revealed either an increase or a constantly high number of tumour cells. In contrast, in patients without recurrence, either clearance of tumour cells or negative or low cell counts were seen. Urokinase plasminogen activator (uPA)-receptor expression on disseminated tumour cells was significantly correlated with increasing tumour cell counts and clinical prognosis. These results demonstrate a systemic component in early solid cancer, indicated by early systemically disseminated tumour cells, which may predict individual disease development.

Enzastaurin inhibits invasion and metastasis in lung cancer by diverse molecules.

BACKGROUND: Enzastaurin (Enz) is a serine/threonine kinase inhibitor blocking protein kinase C (PKC)beta/AKT pathway. However, an ability of this compound to inhibit cancer invasion and metastasis is not yet clearly elucidated. METHODS: The ability of Enz to inhibit invasion and metastasis, and to target molecules was investigated in non-small cell lung cancer (NSCLC) by RT-PCR validated microarray, Matrigel, and in vivo chorionallantoic membrane (CAM) assays. RESULTS: Enzastaurin significantly reduced migration, invasion, and in vivo metastasis to lungs and liver (CAM assay) of diverse NSCLC cell lines. Genes promoting cancer progression (u-PAR, VEGFC, and HIF1alpha) and tumour suppression (VHL, RASSF1, and FHIT) of NSCLC were significantly (P<0.05) down- or upregulated after Enz treatment in H460, A549, and H1299 cells, respectively. Luciferase/chromatin immunoprecipitation analysis showed that Enz transcriptionally controls urokinase-type plasminogen activator receptor (u-PAR) expression by promoter inhibition through Sp1, Sp3, and c-Jun(AP-1). Moreover, siRNA knockdown of u-PAR re-sensitised Enz-resistant cells and induced apoptosis, suggesting u-PAR as a marker of Enz resistance. CONCLUSION: This study shows that Enz inhibits migration, invasion, and in vivo metastasis by targeting u-PAR, besides further targeting progression-related and tumour-suppressor genes in NSCLC. Together with u-PAR being a novel putative marker of Enz response, these data encourage molecularly tailored clinical studies on Enz in NSCLC therapy.

Endosonographic elastography of the anal sphincter in patients with fecal incontinence.

OBJECTIVE: In fecal incontinence the role of elastography has not yet been evaluated. We performed a trial to further characterize the internal and external anal sphincter in patients with fecal incontinence and compared a visual assessment scale with a computerized program for quantifying elastic properties of the anal sphincter. MATERIAL AND METHODS: Fifty consecutive patients with fecal incontinence were studied (n = 31 following lower anterior resection, n = 8 with Crohn's disease, n = 9 following colon surgery, n = 2 others). Elastogram color distribution within the sphincter representing elastic properties was quantified using a visual analog scale and an off-line computerized area calculation program. RESULTS: The main finding was that the inner anal sphincter (IAS) differed significantly from the external anal sphincter (EAS) with regard to elastogram color distribution. There were no significant correlations with clinical and functional parameters. There was, however, a non-significant increase in the percentage of blue (hard) areas in the IAS in patients neoadjuvantly irradiated for rectal or cervical cancer compared to non-irradiated patients, which was accompanied by a significant decrease in the resting sphincter pressure (p < 0.009). CONCLUSIONS: The IAS, a smooth muscle, and the EAS, a striated muscle, have different elastogram color distributions, probably reflecting their different elastic properties. The absence of significant correlations with the major clinical and functional parameters suggests that in routine clinical practice ultrasound real-time elastography may not yield additional information in patients with fecal incontinence. There may be exceptions, particularly in irradiated patients.

QuickMap: a public tool for large-scale gene therapy vector insertion site mapping and analysis.

Several events of insertional mutagenesis in pre-clinical and clinical gene therapy studies have created intense interest in assessing the genomic insertion profiles of gene therapy vectors. For the construction of such profiles, vector-flanking sequences detected by inverse PCR, linear amplification-mediated-PCR or ligation-mediated-PCR need to be mapped to the host cell's genome and compared to a reference set. Although remarkable progress has been achieved in mapping gene therapy vector insertion sites, public reference sets are lacking, as are the possibilities to quickly detect non-random patterns in experimental data. We developed a tool termed QuickMap, which uniformly maps and analyzes human and murine vector-flanking sequences within seconds (available at www.gtsg.org). Besides information about hits in chromosomes and fragile sites, QuickMap automatically determines insertion frequencies in +/- 250 kb adjacency to genes, cancer genes, pseudogenes, transcription factor and (post-transcriptional) miRNA binding sites, CpG islands and repetitive elements (short interspersed nuclear elements (SINE), long interspersed nuclear elements (LINE), Type II elements and LTR elements). Additionally, all experimental frequencies are compared with the data obtained from a reference set, containing 1 000 000 random integrations ('random set'). Thus, for the first time a tool allowing high-throughput profiling of gene therapy vector insertion sites is available. It provides a basis for large-scale insertion site analyses, which is now urgently needed to discover novel gene therapy vectors with 'safe' insertion profiles.

Multiple displacement amplification enables large-scale clonal analysis following retroviral gene therapy.

Analysis of the fate of retrovirally transduced cells after transplantation is often hampered by the scarcity of available DNA. We evaluated a promising method for whole-genome amplification, called multiple displacement amplification (MDA), with respect to even and accurate representation of retrovirally transduced genomic DNA. We proved that MDA is a suitable method to subsequently quantify engraftment efficiencies by quantitative real-time PCR by analyzing retrovirally transduced DNA in a background of untransduced DNA and retroviral integrations found in primary material from a retroviral transplantation model. The portion of these retroviral integrations in the amplified samples was 1.02-fold (range 0.2, to 2.1-fold) the portion determined in the original genomic DNA. Integration site analysis by ligation-mediated PCR (LM-PCR) is essential for the detection of retroviral integrations. The combination of MDA and LM-PCR showed an increase in the sensitivity of integration site analysis, as a specific integration site could be detected in a background of untransduced DNA, while the transduced DNA made up only 0.001%. These results show for the first time that MDA enables large-scale sensitive detection and reliable quantification of retrovirally transduced human genomic DNA and therefore facilitates follow-up analysis in gene therapy studies even from the smallest amounts of starting material.

Identification of an histone H3 acetylated/K4-methylated-bound intragenic enhancer regulatory for urokinase receptor expression.

The transcriptionally regulated urokinase-type plasminogen activator receptor (u-PAR) contributes to cancer progression. Although previous studies have identified multiple 5' regulatory elements, these cis motifs cannot fully account for u-PAR expression prompting a search for hitherto uncharacterized regulatory elements. DNase I hypersensitivity and chromatin immunoprecipitation assays using u-PAR-expressing colon cancer cells indicated a hypersensitive region (+665/+2068) in intron 1 enriched with acetylated histone 3 (H3) and H3 methylated at lysine 4, markers of regulatory regions. The +665/+2068 region increased transcription from a u-PAR-promoter in an orientation- and distance-independent manner fulfilling the criteria of an enhancer. Optimal stimulation of the u-PAR promoter by phorbol ester required this enhancer. Systematic truncations combined with DNase I footprinting revealed two protected regions (+1060/+1099 and +1123/+1134) with deletion of the latter practically abolishing enhancer activity. The +1123/+1134 region harbored non-consensus activator protein-1 and Ets1 binding sites bound with c-Jun (and/or the related JunD/JunB) and c-Fos (and/or the related FosB/Fra-1/Fra-2) as revealed with chromatin immunoprecipitation. Further, nuclear extract from resected colon cancers showed elevated protein binding to a +1123/+1134-spanning probe coordinate with elevated u-PAR protein. Thus, we have defined a novel intragenic enhancer in the u-PAR gene required for constitutive and inducible expression.

Tumor suppressor Pdcd4 inhibits invasion/intravasation and regulates urokinase receptor (u-PAR) gene expression via Sp-transcription factors.

Tumor suppressor Pdcd4 has recently been shown to inhibit invasion by activating activator protein-1 (AP-1); however, little is known of the functionally significant Pdcd4-target genes. The urokinase receptor (u-PAR) promotes invasion/metastasis, and is associated with poor cancer-patient survival. The present study was conducted (1) to investigate a role for Pdcd4 in intravasation, invasion and u-PAR regulation, and (2) to describe mechanisms by which this is achieved. Fourteen cell lines showed reciprocal expression of u-PAR/Pdcd4. Resected tumor/normal tissues of 29 colorectal cancer patients demonstrated a significant inverse correlation between Pdcd4/u-PAR. siRNA-Pdcd4-transfected GEO cells significantly increased endogenous u-PAR mRNA/protein. A u-PAR-promoter-chloramphenicol acetyl transferase (CAT)-reporter was reduced in activity with increasing Pdcd4 expression in RKO. Deletion of a putative Sp-1-binding site (-402/-350) inhibited u-PAR promoter regulation by Pdcd4, this being paralleled by a reduction of Sp1 binding to this region in pdcd4-transfected cells. Pdcd4-transfected cells showed an increase in Sp3 binding to u-PAR promoter region -152/-135, the deletion of which reduces the ability of Pdcd4 to suppress u-PAR promoter activity. Surprisingly, the u-PAR-AP-1 site was not targeted by Pdcd4. Finally, RKO cells overexpressing Pdcd4 showed an inhibition of invasion/intravasation (chicken embryo metastasis assay). These data suggest Pdcd4 as a new negative regulator of intravasation, and qas the invasion-related gene u-PAR. It is the first study to implicate Pdcd4 regulation of gene expression via Sp1/Sp3.

Urokinase plasminogen activator receptor (uPA-R): one potential characteristic of metastatic phenotypes in minimal residual tumor disease.

Evidence of dynamic development of cytokeratin (CK) 18-positive disseminated tumor cells in bone marrow of curatively resected cancer patients has implicated a subclinical minimal residual disease as a biologically relevant component in solid cancer. However, differentiation between irrelevant shed cells and those cells potentially capable of causing later recurrence has not yet been made. In parallel, accumulating data show functional association of the urokinase plasminogen activator (uPA) system and the membranous uPA receptor (uPA-R) with the capacity of a tumor cell for invasion and metastasis. The present study was designed to find descriptive evidence in vivo concerning whether uPA-R could be one potential characteristic for metastatically relevant phenotypes of disseminated tumor cells. An immunocytochemical double staining for uPA-R and CK18 (immunogold/alkaline phosphatase anti-alkaline phosphatase) was performed on perioperative and follow-up bone marrow aspirations of 78 curatively resected gastric cancer patients, if positive tumor cell status had been shown previously with the single alkaline phosphatase anti-alkaline phosphatase method. Bone marrow cells (10(6)) were examined in each assay. Postoperative qualitative and quantitative development of uPA-R-expressing disseminated tumor cells was followed in relation to uPA-R-negative cells and correlated with later clinical relapse. Double staining could be performed perioperatively or in follow-up, or both, in 58 of 78 patients. Expression of uPA-R on perioperatively disseminated tumor cells significantly correlated with later quantitative increases of tumor cells (P = 0.0009). Overall median tumor cell numbers with uPA-R expression significantly increased during follow-up from a median value of 5.5 to 10.0 in 10(6) cells (P = 0.008), and the mean relative percentage of uPA-R-positive, compared with uPA-R-negative, disseminated tumor cells also increased, from 47.9% at surgery to 68.6% in follow-up (P < 0.001). This was mainly due to patients with later tumor relapse (increase from 63.9 to 80.7%, P = 0.001). Patients without relapse showed slight increases at lower percentage levels (5.7% at surgery, 7.4% in follow-up). Differences for relapsing patients were significant (surgery, P = 0.006; follow-up, P < 0.001). Our results suggest from an in vivo model that uPA-R may be one antigen that enables identification and follow-up observations of metastatically relevant phenotypes of disseminated tumor cells, differentiating their individual potential for causing relapse.

Stimulation of urokinase-type plasminogen activator receptor expression by PMA requires JNK1-dependent and -independent signaling modules.

The urokinase-type plasminogen activator receptor (u-PAR) has been implicated in tumor progression, and previous studies have shown that the expression of this gene is strongly up-regulated by PMA. Although the signaling mechanism by which PMA modulates u-PAR expression is not known, the effect of this phorbol ester on the expression of other genes has been ascribed to activation of the c-Raf-1-ERK signaling pathway. However, in the current study we examined an alternate possibility that the inductive effect of PMA on u-PAR expression also required a JNK1-dependent signaling cascade usually associated with stress-inducing stimuli. PMA treatment of the u-PAR-deficient OVCAR-3 ovarian cancer cells, which contain low JNK activities, resulted in a rapid (5 min) increase in JNK activity. Maximal JNK activity (12-fold induction) occurred after 30 min; this preceding the earliest detected rise in u-PAR protein (2 h). Dose-response studies with PMA also indicated that the increased JNK activity was tightly correlated with elevated u-PAR protein levels. The stimulation of u-PAR promoter activity by PMA required an intact upstream AP-1 motif (-184) and in PMA-treated cells this motif was bound with c-Jun as indicated from mobility shift assays. PMA up-regulated the c-Jun trans acting activity as indicated by the higher activity of a GAL4-regulated luciferase reporter in phorbol-ester-treated cells co-transfected with an expression vector encoding the c-Jun transactivation domain fused to the GAL4 DNA-binding domain. The ability of PMA to stimulate u-PAR promoter activity was effectively titrated out by the co-expression of either a kinase-defective JNK1 or a dominant negative MEKK1 the latter being an upstream activator of JNK1. Conversely, u-PAR promoter activity was stimulated by the co-expression of a constitutively active MEKK1 and this induction was antagonized by the inclusion of the kinase-defective JNK1 plasmid. We also determined the biological significance of the JNK1-dependent signaling cascade in regulating u-PAR promoter activity by c-Ha-ras since this oncogene is activated and/or overexpressed in a variety of tumors including ovarian cancer. Transfection of an activated c-Ha-ras into OVCAR-3 cells stimulated u-PAR promoter activity over 20-fold and this could be countered by the individual expression of dominant negative expression constructs to Rac-1, MEKK1 or JNK1. Taken together, these data suggest that the PMA- or c-Ha-Ras-dependent stimulation of u-PAR gene expression requires a JNK1-dependent signaling module and that, at least for PMA, the concurrent stimulation of a JNK1-independent signaling module is also required. Thus, caution should be exercised in invoking linear signaling modules to account for the regulation of inducible gene expression.

c-erbB-2 is of independent prognostic relevance in gastric cancer and is associated with the expression of tumor-associated protease systems.

PURPOSE: The c-erbB-2 gene (encoding the protein p185) is overexpressed in diverse human cancers and has been implicated to be of prognostic value in gastric cancer. Recent studies suggest a role of p185 in tumor progression by specifically promoting the invasive capacity of tumor cells. Therefore, the present study was conducted with the following three objectives: (1) to support the prognostic value of c-erbB-2 in gastric cancer in a large prospective series using a monoclonal antibody and a highly sensitive immunohistochemical method; (2) to determine the association of c-erbB-2 expression with the expression of invasion-related genes; and (3) to perform the first overall multivariate analysis including c-erbB-2 and the invasion-related tumor-associated protease systems. PATIENTS AND METHODS: In a consecutive prospective series of 203 gastric cancer patients (median follow-up, 42 months), expression of c-erbB-2 and a panel of tumor-associated proteases and inhibitors by tumor cells were evaluated semiquantitatively (score 0 to 3) and analyzed for correlation (chi(2) test, Bonferroni-corrected). Kaplan-Meier survival analysis and multivariate Cox analysis were performed to determine the relative prognostic impact of c-erbB-2 and the invasion-related parameters. RESULTS: Kaplan-Meier analysis (log-rank statistics) revealed a significant association of increasing expression of c-erbB-2 with shorter disease-free (P =. 0023) and overall survival (P =.0160). High amounts of p185 were significantly associated with a high expression of urokinase-type plasminogen activator (uPA) (P <.010), uPA-receptor (P =.030), type-1 plasminogen activator inhibitor (PAI) (P <.010), type-2 PAI (P =.021), cathepsin D (P =.036), matrix metalloproteinase-2 (P =. 024), alpha-1-antichymotrypsin (P =.025), and alpha-2-macroglobulin (P =.017). Multivariate analysis considering these proteases/protease inhibitors, in addition to alpha-1-antitrypsin, tissue plasminogen activator, plasminogen, alpha-2-antiplasmin, and antithrombin III, and established prognostic parameters revealed that, in addition to surgical curability, pT stage, pN stage, and PAI-1, c-erbB-2 is an independent prognostic factor for overall survival of curatively resected patients (n = 139; P =.049; relative risk, 1.54; 95% confidence interval, 1.08 to 1.67) and all patients (P =.028; relative risk 1.33; 95% CI, 1.28 to 1.38). CONCLUSION: c-erbB-2 is confirmed as a new independent, functional prognostic parameter for overall survival in gastric cancer, even when a panel of invasion-related factors, including the strong prognostic parameter PAI-1, are considered. The significant correlation of p185 with several tumor-associated proteases supports the hypothesis that c-erbB-2 is a promoter of invasion and metastasis. This strongly suggests that c-erbB-2 may be a promising target for anti-invasive therapy in gastric cancer.

Tumor-associated proteolysis and prognosis: new functional risk factors in gastric cancer defined by the urokinase-type plasminogen activator system.

PURPOSE: The significance of tumor-associated proteolysis as reflected by parameters of the urokinase-type plasminogen activator (uPA) system for prognosis in cancer patients has been proposed because of evidence for its central role in basic mechanisms of invasion and metastasis. The aim of the present study was to evaluate whether the expression of the uPA parameters might be of clinical value in gastric cancer as a tumor/biologically defined risk factor. PATIENTS AND METHODS: In a consecutive series of 203 patients resected for primary gastric cancer, the expression of uPA, uPA-receptor (uPA-R), plasminogen activator inhibitor (PAI)-1, and PAI-2 was determined immunohistochemically. The results were classified semiquantitatively (0 to 3). Patients were followed-up prospectively for a median of 31 months (range, 9 to 56 months). Disease-free and overall survival were analyzed according to Kaplan-Meier and with univariate and multivariate Cox analyses in relation to conventional prognostic factors. RESULTS: Univariate analyses revealed a highly significant inverse correlation of uPA, uPA-R, and PAI-1 expression with survival time (P = .0008, P = .0002, and P = .0002, respectively), whereas PAI-2 demonstrated only a weak correlation. In multivariate analyses, PAI-1 was an independent and strong prognostic factor (P = .005; relative risk, 1.47 per staining degree; 95% confidence interval [CI], 1.31 to 1.64). In pT1/2 tumors and in Laurén's diffuse and mixed types, uPA, uPA-R, and PAI-1 added significant prognostic information. PAI-1 was also associated with survival in the subgroup of lymph node-positive patients. CONCLUSION: PAI-1, uPA, and uPA-R are new functional risk factors reflecting clinical prognosis. In particular, PAI-1 is a new independent variable for the identification of patients at high risk after tumor resection. Our results support the hypothesis that the uPA system probably is of general importance for prognosis of patients with malignant disease, indicating an individual tumor's capacity for invasion and metastasis.

Tumor-associated proteases and inhibitors in gastric cancer: analysis of prognostic impact and individual risk protease patterns.

Expression of proteolytic parameters of the urokinase-type plasminogen activator (uPA) system [uPA receptor (uPA-R), plasminogen activator inhibitor (PAI)-1] has been proven to be an independent prognostic parameter in cancer. However, it has not been considered that the uPA system is interacting with several other protease/inhibitor systems, neither has a comparable prognostic role of these factors been investigated. Moreover, studies evaluating specific protease patterns indicating high individual risk are missing completely. Therefore, in a consecutive prospective series of 203 gastric cancer patients, the expression of activators (plasminogen, tPA, MMP-2, cathepsin D, antithrombin 3) and inhibitors (alpha-2-antiplasmin, alpha-2-macroglobulin, alpha-1-antitrypsin, alpha-1-antichymotrypsin) of proteolysis was studied immunohistochemically in the tumor epithelium semiquantitatively (score 0-3) in addition to the uPA system. Kaplan-Meier analysis (median time of follow-up 31 months) revealed a significant association of cathepsin D (P=0.0042), alpha-2-macroglobulin (P=0.0281) and antitrypsin (P=0.0372) with disease-free survival and of cathepsin D (P=0.0018), antitrypsin (P=0.0112) and antichymotrypsin (P=0.0002) with overall survival. Multivariate Cox analysis performed to correct these results for relative impact of the uPA system and established prognostic factors showed PAI-1 (disease-free survival: P=0.002, relative risk 1.86; overall survival: P=0.005, relative risk 1.39), pT and pN as independent parameters. Cathepsin D was shown to have an independent impact on disease-free survival (P=0.020, relative risk 2.98). Comparative chi-square analysis of cases with poor and good prognoses revealed that in patients with good clinical outcome, inhibitors of proteolysis are correlated significantly, whereas in patients with poor prognosis activators of proteolysis are significantly associated preferentially and significant correlations with the uPA-R are dominant. For detailed pattern analysis, stepwise overall Kaplan-Meier analyses were performed in subgroups of high uPA-R-, uPA-, PAI1- and cathepsin D expression for two additional proteases each. From these analyses, the combination of high (score 2/3) expression of uPA-R, PAI-1, antichymotrypsin and alpha-2-macroglobulin was identified as a high-risk pattern, representing parameters known to be essential for uPA-R internalization and recycling. This suggests some of the uPA-associated proteases and inhibitors investigated as univariate prognostic parameters in gastric cancer. Cathepsin D is a new independent parameter for disease-free survival. The study further demonstrates that a protease pattern promoting uPA-R recycling in tumor cells especially indicates high individual risk tumors in gastric cancer.

Immunocytochemical phenotyping of disseminated tumor cells in bone marrow by uPA receptor and CK18: investigation of sensitivity and specificity of an immunogold/alkaline phosphatase double staining protocol.

Phenotyping of cytokeratin (CK)18-positive cells in bone marrow is gaining increasing importance for future prognostic screening of carcinoma patients. Urokinase-type plasminogen activator receptor (uPA-R) is one example of a potential aggressive marker for those cells. However, a valid and reliable double staining method is needed. Using monoclonal antibodies against uPA-R and CK18, we modified an immunogold/alkaline phosphatase double staining protocol. UPA-R/CK18-positive tumor cell controls exhibited black uPA-R staining in 15-80% of cases and red CK18 staining in almost 100% of tumor cells. Isotype- and cross-matched controls were completely negative. Bone marrow from healthy donors was always CK18-negative. Reproducibility of CK18-positive cell detection was estimated in a series of specimens from 61 gastric cancer patients comparatively stained with the single alkaline phosphatase-anti-alkaline phosphatase (APAAP) and our double staining method (10(6) bone marrow cells/patient). In four cases, double staining could not reproduce CK18-positive cells. In 34 cases it revealed fewer or equal numbers, and in 23 cases more CK18-positive cells than the APAAP method. Overall quantitative analysis of detected cell numbers (838 in APAAP, range 1-280 in 10(6); double staining 808, range 0-253) demonstrated relative reproducibility of APAAP results by double staining of 97%. Correlation of results between both methods was significant (p < 0.001, linear regression). Sensitivity of double staining tested in logarithmic tumor cell dilutions was one CK18-positive cell in 300,000. Specific uPA-R staining was seen on CK18-positive cells in bone marrow from 29 of 61 patients, and also on single surrounding bone marrow cells. To test the specificity of this staining, bone marrow cytospins from 10 patients without tumor disease were stained for uPA-R with the APAAP method. uPA-R expression was confirmed in all 10 cases, with a mean of 6.5% uPA-R-positive cells in 1000 bone marrow cells (SEM 1.2%). These results suggest that our double staining protocol is a sensitive, reproducible, and specific method for routine uPA-R phenotyping of disseminated CK18-positive cells in bone marrow of carcinoma patients.

Effects of antacids on the clinical pharmacokinetics of drugs. An update.

Since a previous review by Hurwitz was published in 1977 a large number of reports on drug interactions with antacids have appeared, few of which are of clinical relevance. Tetracyclines form insoluble complex molecules by metal ion chelation with various antacids; tetracycline absorption may be decreased by more than 90% by this interaction. Of the new class of quinolone antibiotics, the absorption of ciprofloxacin and ofloxacin is reduced by 50 to 90% in the presence of aluminium- and magnesium hydroxide-containing antacids. In contrast to early work showing inhibition of the absorption of beta-adrenergic blocking drugs by antacids, subsequent studies did not confirm a reduction in the bioavailability of either atenolol or propranolol during antacid treatment; indeed, they showed an increase in the plasma concentrations of metoprolol when the drug was coadministered with an antacid. The bioavailability of captopril was significantly reduced in the presence of an antacid, and lower plasma concentrations of this angiotensin-converting enzyme inhibitor were accompanied by a reduction of its effect on the systolic blood pressure of the patients. The absorption of the cardiac glycosides digoxin and digitoxin is not inhibited by antacids to a significant degree, although earlier studies had shown a positive effect when the dissolution of the glycoside preparations was relatively poor. Antacids reduce the bioavailability of the H2-receptor antagonists cimetidine and ranitidine only when high antacid doses are used and when the drugs are administered simultaneously. The bioavailability of famotidine was not significantly altered by a potent antacid preparation, although a trend towards reduced absorption was observed. Iron absorption is significantly decreased in the presence of sodium bicarbonate and calcium carbonate, but is nearly complete when coadministered with aluminium-magnesium hydroxide. Nonsteroidal anti-inflammatory drugs such as naproxen, tenoxicam, ketoprofen, ibuprofen and piroxicam are not affected in their absorption by antacid treatment. Theophylline bioavailability is unchanged when the drug is given together with antacids, although its rate of absorption may be altered, leading to a reduction or an increase in the time of the occurrence of peak plasma drug concentrations.

Superoxide, hydroxyl and fatty acid radical scavenging by aminosalicylates. Direct evaluation with electron spin resonance spectroscopy.

Reactive oxygen radicals such as superoxide and hydroxyl radicals, as well as intermediate unsaturated fatty acid radicals, have been proposed as playing an important role in various diseases including inflammatory bowel disease (IBD). In this study we evaluated radical scavenger properties of aminosalicylates used in the therapy of IBD using spin trapped electron spin resonance spectroscopy. 5-Aminosalicylic acid (5-ASA), 4-aminosalicylic acid and olsalazine had superoxide radical scavenger properties (IC50 = 0.4, 0.4 and 1.0 mM, respectively). 5-ASA and benzalazine also inhibited hydroxyl radicals (IC50 = 6.5 mM). Fatty acid radicals were not inhibited by aminosalicylates. Our results support the hypothesis that therapeutically active compounds may be oxygen radical scavengers and that fatty acid radical scavenging has to be performed by drugs other than aminosalicylates.

Review article: mechanisms of action of mesalazine in preventing colorectal carcinoma in inflammatory bowel disease.

A series of epidemiological, experimental and preliminary clinical trials strongly suggest that mesalazine or 5-aminosalicyclic acid (5-ASA) may have antineoplastic and potentially prophylactic chemopreventive properties. It is assumed that mesalazine may have similar genetic and molecular targets as nonsteroidal anti-inflammatory drugs (NSAIDs), which is further supported by its close similarity with aspirin, differing only in its structure by the presence of an amino group at position 5 of the benzene ring. The putative chemopreventive actions include the inhibition of inflammatory cascades and/or reactions involved in cell growth and proliferation, such as cyclo-oxygenase (COX-1 and COX-2), which regulate cell proliferation through the formation of prostaglandins; lipoxygenase; nuclear factor kappaB (NFkappaB), responsible for the subsequent expression of pro-inflammatory molecules; MAP kinases and Bcl-2, as well as the activation of apoptotic processes, such as the stimulation of intestinal sphingomyelinase. The peroxisome-proliferator-activated receptor delta (PPARdelta), which also regulates gene transcription, is thought to play a role in both inflammatory and non-inflammatory driven carcinogenesis. This may be another significant target. It is hypothesized that 5-ASAs may prevent the enhancing effect of prostaglandins on PPARdelta binding to DNA by its COX inhibitory properties, decreasing proliferation of colorectal mucosal cells in non-inflammatory bowel disease patients with sporadic polyps of the large bowel.

Modulation of immune response by blood transfusion: evidence for a differential effect of allogeneic and autologous blood in colorectal cancer surgery.

Even though blood transfusion-associated immunomodulatory effects have been reported, the basic immune mechanism is still not understood. Data from studies on the clinical effects of allogeneic blood-induced immunosuppression are contradictory. However, there are indications that autologous blood transfusion is not immunologically neutral but has intrinsic immunomodulatory potential. Therefore we investigated in vivo different immunological mediators in 56 randomized patients of a study comparing autologous and allogeneic blood transfusion in colorectal cancer surgery. Soluble IL-2 receptor, which is an indicator of general immune activation and the following immunologic refractory phase, indicated immunosuppression was more elevated at the seventh postoperative day in patients with allogeneic transfusions (p = .013) and autologous transfusions (p = .0003). The immunologic determination of TNF-alpha showed a significant postoperative increase in patients with autologous transfusions only (p = .0031). However, postoperative increase of soluble TNF-receptors p55 and p75 was also significant in patients transfused with allogenic blood (p = .022; p = .0014). The response to tetanus toxoid vaccination, an indicator of humoral immunity, was higher in patients transfused with allogeneic rather than autologous blood (p = .082), whereas responses of patients with autologous transfusions were even lower than in nontransfused patients. The reciprocal was already found for cell-mediated immunity determined by epicutaneously tested delayed-type hypersensitivity-reactions. IL-10 levels, an indicator of cellular immunosuppression, were determined in 27 additional patients before operation, immediately postoperative, and at the seventh postoperative day. IL-10 was found elevated immediately postoperative in allogeneic (p = .011) and nontransfused patients only (p = .042). The data from this study substantiate recent findings of a different immunomodulatory potential of allogeneic and autologous blood transfusion. They furthermore support the hypothesis that autologous blood transfusion does not contain immunologically neutral effects of allogeneic blood, but itself exerts an immunomodulatory effect.