Training and validation of a novel 4-miRNA ratio model (MiCaP) for prediction of postoperative outcome in prostate cancer patients.

Background: New molecular biomarkers for prostate cancer (PC) prognosis are urgently needed. Ratio-based models are attractive, as they require no additional normalization. Here, we train and independently validate a novel 4-miRNA prognostic ratio model for PC. Patients and methods: By genome-wide miRNA expression profiling of PC tissue samples from 123 men who underwent radical prostatectomy (RP) (PCA123, training cohort), we identified six top candidate prognostic miRNAs and systematically tested their ability to predict postoperative biochemical recurrence (BCR). The best miRNA-based prognostic ratio model (MiCaP) was validated in two independent cohorts (PCA352 and PCA476) including >800 RP patients in total. Clinical end points were BCR and prostate cancer-specific survival (CSS). The prognostic potential of MiCaP was assessed by univariate and multivariate Cox-regression analyses and Kaplan-Meier analyses. Results: We identified a 4-miRNA ratio model, MiCaP (miR-23a-3p×miR-10b-5p)/(miR-133a×miR-374b-5p), that predicted time to BCR independently of routine clinicopathologic variables in the training cohort (PCA123) and was successfully validated in two independent RP cohorts. In addition, MiCaP was a significant predictor of CSS in univariate analysis [HR 3.35 (95% CI 1.34 - 8.35), P = 0.0096] and in multivariate analysis [HR 2.43 (95% CI 1.45-4.07), P = 0.0210]. As proof-of-principle, we also analyzed MiCaP in plasma samples from 111 RP patients. A high MiCaP score in plasma was significantly associated with BCR (P = 0.0036, Kaplan-Meier analysis). Limitations include low mortality rates (CSS: 5.4%). Conclusions: We identified a novel 4-miRNA ratio model (MiCaP) with significant independent prognostic value in three RP cohorts, indicating promising potential to improve PC risk stratification.

Mutations in the TLR3 signaling pathway and beyond in adult patients with herpes simplex encephalitis.

Herpes simplex encephalitis (HSE) in children has previously been linked to defects in type I interferon production downstream of Toll-like receptor (TLR)3. In the present study, we used whole-exome sequencing to investigate the genetic profile of 16 adult patients with a history of HSE. We identified novel mutations in IRF3, TYK2 and MAVS, molecules involved in generating innate antiviral immune responses, which have not previously been associated with HSE. Moreover, data revealed mutations in TLR3, TRIF, TBK1 and STAT1 known to be associated with HSE in children but not previously described in adults. All discovered mutations were heterozygous missense mutations, the majority of which were associated with significantly decreased antiviral responses to HSV-1 infection and/or the TLR3 agonist poly(I:C) in patient peripheral blood mononuclear cells compared with controls. Altogether, this study demonstrates novel mutations in the TLR3 signaling pathway in molecules previously identified in children, suggesting that impaired innate immunity to HSV-1 may also increase susceptibility to HSE in adults. Importantly, the identification of mutations in innate signaling molecules not directly involved in TLR3 signaling suggests the existence of innate immunodeficiencies predisposing to HSE beyond the TLR3 pathway.

Genome-wide study of association and interaction with maternal cytomegalovirus infection suggests new schizophrenia loci.

Genetic and environmental components as well as their interaction contribute to the risk of schizophrenia, making it highly relevant to include environmental factors in genetic studies of schizophrenia. This study comprises genome-wide association (GWA) and follow-up analyses of all individuals born in Denmark since 1981 and diagnosed with schizophrenia as well as controls from the same birth cohort. Furthermore, we present the first genome-wide interaction survey of single nucleotide polymorphisms (SNPs) and maternal cytomegalovirus (CMV) infection. The GWA analysis included 888 cases and 882 controls, and the follow-up investigation of the top GWA results was performed in independent Danish (1396 cases and 1803 controls) and German-Dutch (1169 cases, 3714 controls) samples. The SNPs most strongly associated in the single-marker analysis of the combined Danish samples were rs4757144 in ARNTL (P=3.78 × 10(-6)) and rs8057927 in CDH13 (P=1.39 × 10(-5)). Both genes have previously been linked to schizophrenia or other psychiatric disorders. The strongest associated SNP in the combined analysis, including Danish and German-Dutch samples, was rs12922317 in RUNDC2A (P=9.04 × 10(-7)). A region-based analysis summarizing independent signals in segments of 100 kb identified a new region-based genome-wide significant locus overlapping the gene ZEB1 (P=7.0 × 10(-7)). This signal was replicated in the follow-up analysis (P=2.3 × 10(-2)). Significant interaction with maternal CMV infection was found for rs7902091 (P(SNP × CMV)=7.3 × 10(-7)) in CTNNA3, a gene not previously implicated in schizophrenia, stressing the importance of including environmental factors in genetic studies.

Common variant at 16p11.2 conferring risk of psychosis.

Epidemiological and genetic data support the notion that schizophrenia and bipolar disorder share genetic risk factors. In our previous genome-wide association study, meta-analysis and follow-up (totaling as many as 18 206 cases and 42 536 controls), we identified four loci showing genome-wide significant association with schizophrenia. Here we consider a mixed schizophrenia and bipolar disorder (psychosis) phenotype (addition of 7469 bipolar disorder cases, 1535 schizophrenia cases, 333 other psychosis cases, 808 unaffected family members and 46 160 controls). Combined analysis reveals a novel variant at 16p11.2 showing genome-wide significant association (rs4583255[T]; odds ratio=1.08; P=6.6 × 10(-11)). The new variant is located within a 593-kb region that substantially increases risk of psychosis when duplicated. In line with the association of the duplication with reduced body mass index (BMI), rs4583255[T] is also associated with lower BMI (P=0.0039 in the public GIANT consortium data set; P=0.00047 in 22 651 additional Icelanders).

Next-generation sequencing identifies germline MRE11A variants as markers of radiotherapy outcomes in muscle-invasive bladder cancer.

BACKGROUND: Muscle-invasive bladder cancer (MIBC) can be cured by radical radiotherapy (RT). We previously found tumour MRE11 expression to be predictive of survival following RT in MIBC, and this was independently validated in a separate institute. Here, we investigated germline MRE11A variants as possible predictors of RT outcomes in MIBC, using next-generation sequencing (NGS). PATIENTS AND METHODS: The MRE11A gene was amplified in germline DNA from 186 prospectively recruited MIBC patients treated with RT and sequenced using bar-coded multiplexed NGS. Germline variants were analysed for associations with cancer-specific survival (CSS). For validation as a prognostic or predictive marker, rs1805363 was then genotyped in a cystectomy-treated MIBC cohort of 256 individuals. MRE11A mRNA isoform expression was measured in bladder cancer cell lines and primary tumour samples. RESULTS: Carriage of at least one of six (five novel) rare variants was associated with the worse RT outcome (hazard ratio [HR] 4.04, 95% confidence interval [95% CI] 1.42-11.51, P = 0.009). The single-nucleotide polymorphism (SNP), rs1805363 (minor allele frequency 11%), was also associated with worse CSS (per-allele HR 2.10, 95% CI 1.34-3.28, Ptrend = 0.001) following RT in MIBC, with a gene-dosage effect observed, but no effect seen on CSS in the cystectomy cohort (Ptrend = 0.89). Furthermore, rs1805363 influenced relative MRE11A isoform expression, with increased isoform 2 expression with carriage of the rs1805363 minor A allele. CONCLUSIONS: Germline MRE11A SNP rs1805363 was predictive of RT, but not of cystectomy outcome in MIBC. If successfully validated in an independent RT-treated cohort, this SNP could be a useful clinical tool for selecting patients for bladder-conserving treatment.

Prognostic significance of aberrantly silenced ANPEP expression in prostate cancer.

BACKGROUND: Novel biomarkers for prostate cancer (PC) are urgently needed. This study investigates the expression, epigenetic regulation, and prognostic potential of ANPEP in PC. METHODS: Aminopeptidase N (APN; encoded by ANPEP) expression was analysed by immunohistochemistry using tissue microarrays representing 267 radical prostatectomy (RP) and 111 conservatively treated (CT) PC patients. Clinical end points were recurrence-free survival (RFS) and cancer-specific survival (CSS), respectively. The ANPEP promoter methylation levels were determined by bisulphite sequencing or MethyLight analysis in 278 nonmalignant and PC tissue samples, and in cell lines. RESULTS: The APN expression was significantly downregulated in PC compared with nonmalignant prostate tissue samples. Aberrant promoter hypermethylation was frequently observed in PC tissue samples, and 5-aza-2'-deoxycytidine induced ANPEP expression in three hypermethylated prostate cell lines, suggesting epigenetic silencing. Negative APN immunoreactivity was significantly associated with short RFS and short CSS in the RP and CT cohort, respectively, independently of routine clinicopathological predictors. Combining APN with a known angiogenesis marker (vascular endothelial growth factor or microvessel density) improved risk prediction significantly in both cohorts. CONCLUSION: Our results suggest negative APN immunoreactivity as a new independent adverse prognostic factor for patients with clinically localised PC and, furthermore, that epigenetic mechanisms are involved in silencing of ANPEP in PC.

Association between genetic variation in a region on chromosome 11 and schizophrenia in large samples from Europe.

Recent molecular studies have implicated common alleles of small to moderate effect and rare alleles with larger effect sizes in the genetic architecture of schizophrenia (SCZ). It is expected that the reliable detection of risk variants with very small effect sizes can only be achieved through the recruitment of very large samples of patients and controls (that is tens of thousands), or large, potentially more homogeneous samples that have been recruited from confined geographical areas using identical diagnostic criteria. Applying the latter strategy, we performed a genome-wide association study (GWAS) of 1169 clinically well characterized and ethnically homogeneous SCZ patients from a confined area of Western Europe (464 from Germany, 705 from The Netherlands) and 3714 ethnically matched controls (1272 and 2442, respectively). In a subsequent follow-up study of our top GWAS results, we included an additional 2569 SCZ patients and 4088 controls (from Germany, The Netherlands and Denmark). Genetic variation in a region on chromosome 11 that contains the candidate genes AMBRA1, DGKZ, CHRM4 and MDK was significantly associated with SCZ in the combined sample (n=11 540; P=3.89 × 10(-9), odds ratio (OR)=1.25). This finding was replicated in 23 206 independent samples of European ancestry (P=0.0029, OR=1.11). In a subsequent imaging genetics study, healthy carriers of the risk allele exhibited altered activation in the cingulate cortex during a cognitive control task. The area of interest is a critical interface between emotion regulation and cognition that is structurally and functionally abnormal in SCZ and bipolar disorder.

Expression of MAGE-A3, NY-ESO-1, LAGE-1 and PRAME in urothelial carcinoma.

BACKGROUND: The potential for cancer-testis (CT) antigens as targets for immunotherapy in cancer patients has been heavily investigated, and currently cancer vaccine trials based on the CT antigens, MAGE-A3 and NY-ESO-1, are being carried out. METHODS: We used specific q-RT-PCR assays to analyse the expression of the CT genes MAGE-A3, NY-ESO-1 (CTAG1B), LAGE-1 (CTAG2) and PRAME in a panel of bladder tumours from 350 patients with long-term follow-up and detailed treatment information. RESULTS: Overall, 43% of the tumours expressed MAGE-A3, 35% expressed NY-ESO-1, 27% expressed LAGE-1 and 20% expressed PRAME. In all, 56% of the tumours expressed at least one of the CT genes analysed. Univariate Cox regression analysis of CT gene expression in non-muscle-invasive tumours showed that expression of MAGE-A3 (P=0.026), LAGE-1 (P=0.001) and NY-ESO-1 (P=0.040) was significantly associated with a shorter progression-free survival. In addition, we found that patients with tumours expressing PRAME responded poorly to chemotherapy (P=0.02, χ(2)-test). CONCLUSION: Cancer-testis genes are frequently expressed in bladder cancer and especially in tumours of high stage and grade. In addition, the CT gene expression may have both prognostic and predictive value. Development of specific immunotherapy against the CT antigens in bladder cancer may ultimately increase patient survival.

The miR-143/-145 cluster regulates plasminogen activator inhibitor-1 in bladder cancer.

BACKGROUND: Upregulation of the proto-oncogene plasminogen activator inhibitor-1 (PAI-1) is a common hallmark of various solid tumours, but the mechanisms controlling its expression are not fully understood. METHODS: We investigate microRNAs (miRNAs) regulating PAI-1 in a panel of normal bladder urothelial biopsies, superficial Ta bladder tumours and invasive T1-T4 tumours using expression microarrays and qRT-PCR. The prognostic implications of PAI-1 deregulation are established by tissue microarray staining of non-muscle-invasive bladder tumours. MicroRNA repression of PAI-1 is assayed by ectopic miRNA expression, argonaute immunoprecipitation and luciferase assays. RESULTS: We found that the miR-143/-145 cluster is downregulated in all stages of bladder cancer and inversely correlated with PAI-1 expression. Mature miR-143 and miR-145 are coordinately expressed, and both directly target the PAI-1 3'UTR, leading to reduced PAI-1 mRNA and protein levels. Furthermore, we show that PAI-1 and miR-145 levels may serve as useful prognostic markers for non-muscle-invasive bladder tumours for which accurate progressive outcome is currently difficult to predict. CONCLUSION: This report provides the first evidence for direct miRNA regulation of PAI-1 in bladder cancer. We also demonstrate mRNA co-targeting by a cluster of non-family miRNAs, and suggest miR-145 and PAI-1 as clinically relevant biomarkers in bladder cancer.

Analysis of molecular intra-patient variation and delineation of a prognostic 12-gene signature in non-muscle invasive bladder cancer; technology transfer from microarrays to PCR.

BACKGROUND: Multiple clinical risk factors and genetic profiles have been demonstrated to predict progression of non-muscle invasive bladder cancer; however, no easily clinical applicable gene signature has been developed to predict disease progression independent of disease stage and grade. METHODS: We measured the intra-patient variation of an 88-gene progression signature using 39 metachronous tumours from 17 patients. For delineation of the optimal quantitative reverse transcriptase PCR panel of markers, we used 115 tumour samples from patients in Denmark, Sweden, UK and Spain. RESULTS: Analysis of intra-patient variation of the molecular markers showed 71% similar classification results. A final panel of 12 genes was selected, showing significant correlation with outcome. In multivariate Cox regression analysis, we found that the 12-gene signature was an independent prognostic factor (hazard ratio=7.4 (95% confidence interval: 3.4-15.9), P<0.001) when adjusting for stage, grade and treatment. Independent validation of the 12-gene panel and the determined cut-off values is needed and ongoing. CONCLUSION: Intra-patient marker variation in metachronous tumours is present. Therefore, to increase test sensitivity, it may be necessary to test several metachronous tumours from a patient's disease course. A PCR-based 12-gene signature significantly predicts disease progression in patients with non-muscle invasive bladder cancer.

Repression of KIAA1199 attenuates Wnt-signalling and decreases the proliferation of colon cancer cells.

BACKGROUND: The KIAA1199 transcript is upregulated in colon adenomas and downregulated upon ß-catenin knockdown. METHODS: Transcript profiling was performed on >500 colon biopsies, methylation profiling data were compared with transcript data. Immunohistochemistry assessed KIAA1199 protein expression in 270 stage II/III tumours (>3 years follow-up). The effects of stable KIAA1199 knockdown in SW480 cells (three different constructs) were studied using transcriptional profiling, proliferation and protein analysis. RESULTS: The KIAA1199 transcript was strongly upregulated in 95% of adenocarcinomas. Absent expression in normal mucosa correlated with KIAA1199 promotor methylation. Nuclear and cytoplasmic KIAA1199 protein expression was identified in colon adenocarcinomas and other types of cancers. A subpopulation of patients with tumours strongly expressing KIAA1199 in the nucleus showed a better outcome with regard to recurrence as lung or liver metastases. The KIAA1199 knockdown affected the cell cycle and the Wnt-signalling pathway. Reduced cellular proliferation and decreased KI67, phosphorylated retinoblastoma, ß-catenin and ASCL2 protein expression supported these findings. Eighteen Wnt-signalling genes differentially expressed upon KIAA1199 knockdown correlated with the KIAA1199 expression profile in clinical specimens. CONCLUSION: The KIAA1199 knockdown attenuates the effects of the Wnt/ß-catenin signalling and it may thus be regarded as a regulatory part of this pathway.

Low ANXA10 expression is associated with disease aggressiveness in bladder cancer.

BACKGROUND: Markers for outcome prediction in bladder cancer are urgently needed. We have previously identified a molecular signature for predicting progression in non-muscle-invasive bladder cancer. ANXA10 was one of the markers included in the signature and we now validated the prognostic relevance of ANXA10 at the protein level. METHODS: We investigated ANXA10 expression by immunohistochemistry using a tissue microarray with 249 Ta and T1 urothelial carcinomas. The expression of ANXA10 was also investigated in an additional set of 97 more advanced tumours. The functional role of ANXA10 in cell lines was investigated by siRNA-mediated ANXA10 knockdown using wound-healing assays, proliferation assays, and ingenuity pathway analysis. RESULTS: Low expression of ANXA10 correlated with shorter progression-free survival in patients with stage Ta and T1 tumours (P<0.00001). Furthermore, patients with more advanced tumours and low ANXA10 expression had an unfavourable prognosis (P<0.00001). We found that ANXA10 siRNA transfected cells grew significantly faster compared with control siRNA transfected cells. Furthermore, a wound-healing assay showed that ANXA10 siRNA transfected cells spread along wound edges faster than control transfected cells. CONCLUSION: We conclude that ANXA10 may be a clinical relevant marker for predicting outcome in both early and advanced stages of bladder cancer.

Dysregulation of the transcription factors SOX4, CBFB and SMARCC1 correlates with outcome of colorectal cancer.

The aim of this study was to identify deregulated transcription factors (TFs) in colorectal cancer (CRC) and to evaluate their relation with the recurrence of stage II CRC and overall survival. Microarray-based transcript profiles of 20 normal mucosas and 424 CRC samples were used to identify 51 TFs displaying differential transcript levels between normal mucosa and CRC. For a subset of these we provide in vitro evidence that deregulation of the Wnt signalling pathway can lead to the alterations observed in tissues. Furthermore, in two independent cohorts of microsatellite-stable stage II cancers we found that high SOX4 transcript levels correlated with recurrence (HR 2.7; 95% CI, 1.2-6.0; P=0.01). Analyses of approximately 1000 stage I-III adenocarcinomas, by immunohistochemistry, revealed that patients with tumours displaying high levels of CBFB and SMARCC1 proteins had a significantly better overall survival rate (P=0.0001 and P=0.0275, respectively) than patients with low levels. Multivariate analyses revealed that a high CBFB protein level was an independent predictor of survival. In conclusion, several of the identified TFs seem to be involved in the progression of CRC.

No evidence of somatic aryl hydrocarbon receptor interacting protein mutations in sporadic endocrine neoplasia.

Germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene were recently observed in patients with pituitary adenoma predisposition (PAP). Though AIP mutation-positive individuals with prolactin-, mixed growth hormone/prolactin-, and ACTH-producing pituitary adenomas as well as non-secreting pituitary adenomas have been reported, most mutation-positive patients have had growth hormone-producing adenomas diagnosed at relatively young age. Pituitary adenomas are also component tumors of some familial endocrine neoplasia syndromes such as multiple endocrine neoplasia type 1 (MEN1) and Carney complex (CNC). Genes underlying MEN1 and CNC are rarely mutated in sporadic pituitary adenomas, but more often in other lesions contributing to these two syndromes. Thus far, the occurrence of somatic AIP mutations has not been studied in endocrine tumors other than pituitary adenomas. Here, we have analyzed 32 pituitary adenomas and 79 other tumors of the endocrine system for somatic AIP mutations by direct sequencing. No somatic mutations were identified. However, two out of nine patients with prolactin-producing adenoma were shown to harbor a Finnish founder mutation (Q14X) with a complete loss of the wild-type allele in the tumors. These results are in agreement with previous studies in that prolactin-producing adenomas are component tumors in PAP. The data also support the previous finding that somatic AIP mutations are not common in pituitary adenomas and suggest that such mutations are rare in other endocrine tumors as well.

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.

Activity of the human blood group ABO, Se, H, Le, and X gene-encoded glycosyltransferases in normal and malignant bladder urothelium.

Immunohistochemistry has led to the finding of an expression of ABO-related blood group antigens in normal and malignant bladder urothelium which is different from that found on erythrocytes from the same individual. This includes a loss of blood group ABO expression in malignant urothelium, and the expression of Leb antigens in normal and malignant cells from individuals with Le(a+b-) and Le(a-b-) erythrocytes. To elucidate the mechanism of this blood group antigen expression in urothelium we have analyzed the activity of the specific glycosyltransferases encoded by the ABO, Se, H, Le, and X blood group genes in normal and malignant urothelium. Biopsies of normal urothelium were obtained from 22 individuals and biopsies of urothelial tumors from 20 individuals. The tissue donors were typed for ABO, Lewis, and secretor status on erythrocytes and saliva. The biopsies were disaggregated to single cell suspensions, and the activity of the individual glycosyltransferases was determined as pmol of labeled sugar incorporated by oligosaccharide acceptors per 100,000 cells. The A (alpha-3-N-acetyl-D-galactosaminyl) and B (alpha-3-D-galactosyl) gene-specified transferases showed no activity in malignant cells, whereas all other enzymes examined were expressed in both normal and malignant cells. Secretors and nonsecretors showed the same alpha-2-L-fucosyltransferase activity in both normal and malignant cells, whereas the alpha-3-L-fucosyltransferase was reduced (P less than 0.02) in malignant cells from Lewis positive individuals. The Lewis gene-encoded alpha-4-L-fucosyltransferase showed a similar activity in Lewis positive and negative individuals. These results indicate that the disappearance of A and B blood group antigens in bladder tumors and the expression of Leb antigens in normal and malignant cells from individuals with Le(a+b-) and Le(a-b-) erythrocytes are due to corresponding differences in glycosyltransferases. The results indicate that the ABO, H, Se, and Le genes are subjected to a tissue-dependent differential expression.

The blood group ABO gene transcript is down-regulated in human bladder tumors and growth-stimulated urothelial cell lines.

The molecular mechanism that in human bladder tumors leads to the loss of blood group ABO glycosyltransferase activity and, thereby, the loss of ABO antigens was investigated. In 15 tumors and 3 normal biopsies from blood group AB individuals and 7 tumors and 3 normal biopsies from blood group O individuals, mRNA was detected by a reverse transcription PCR (RT-PCR) assay, and the ABO blood group structure was determined by immunohistology. The RT-PCR spanned several introns in the ABO gene to exclude DNA contamination, and the RT-PCR product was shown to reflect the ABO gene message by dideoxy sequencing. The ABO mRNA was present in normal urothelium and low-grade tumors but disappeared from high grade tumors. This correlation to tumor grade was significant (P<0.04). Immunohistochemistry with monoclonal anti-blood group antibodies showed a complete correlation between the presence of mRNA and the presence of AB carbohydrate structures on cell surfaces. In two urothelial cell lines, genotyped as A/- and A/A, growth stimulation with the cholera toxin B subunit led to a total loss of ABO mRNA, and epidermal growth factor stimulation had an identical effect on one of the cell lines. We conclude that the ABO glycosylation in normal and malignant urothelium is regulated at the mRNA level, and that a mechanism associated with cell proliferation may trigger down-regulation of ABO mRNA.

Human urinary bladder carcinoma glycoconjugates expressing T-(Gal beta(1-3)GalNAc alpha 1-O-R) and T-like antigens: a comparative study using peanut agglutinin and poly- and monoclonal antibodies.

T- and T-like antigens on glycoproteins and glycolipids were examined in extracts of human urinary bladder tumors and normal tissue by Western blot analysis and reagent binding to thin layer chromatograms. Three different anti-T-reagents were used: peanut (Arachis hypogaea) lectin (PNA) and mono- and polyclonal antibodies specific for T-antigen (Gal beta(1-3)GalNAc alpha 1-O-R). Immunodetection with the T-specific reagents in nitrocellulose replicas of bladder tumor glycoproteins, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, demonstrated tumor-specific T-antigen-bearing glycoproteins compared to normal urothelial glycoproteins. In addition, a remarkable difference in binding was found between the immunological reagents and PNA lectin. PNA showed major reactivity to a 28-kD glycoprotein extracted from tumors. Monoclonal anti-T-antibody (clone HH8) showed major reactivity with an M(r) 34,000 glycoprotein, and polyclonal anti-T-antibody showed major reactivity with an M(r) 36,000 glycoprotein. PNA agarose column affinity-purified tumor glycoproteins did not bind the antibodies. Glycoproteins, M(r) 28,000 and 34,000, were shown to be O-linked by stepwise deglycosylation. In solid phase monosaccharide inhibition tests, galactose followed by N-acetyl-galactosamine were the most potent monosaccharides inhibiting binding to immobilized bladder tumor glycoproteins. None of the anti-T-reagents reacted with glycolipids extracted from tumor tissue. It is concluded that PNA lectin, in addition to the T-disaccharide, reacts with other protein-anchored carbohydrate structures in carcinomas.

Allelic deletions of cell growth regulators during progression of bladder cancer.

Cell growth regulators include proteins of the p53 pathway encoded by the genes CDKN2A (p16, p14arf), MDM2, TP53, and CDKN1A (p21) as well as proteins encoded by genes like RB1, E2F, and MYCL. In the present study we investigated allelic deletions of all these genes in each recurrent bladder tumor from well-defined clinical material with more than 3 years of follow-up. We followed three groups (22 or 23 patients/group) of patients with: (a) recurrent noninvasive tumors (Ta); (b) primary muscle-invasive tumors (T2-T4); and (c) progressing tumors (Ta/T1 --> T2/T4). We found a significant difference in the numbers of gene loci hit by deletions muscle-invasive versus noninvasive tumors (P = 0.0000002), with the genes most often hit by deletions in muscle-invasive tumors being TP53, RB1, and MYCL. A number of novel findings were made. Losses of MYCL and RB1 alleles were more pronounced in patients having concomitant field disease because 11 of 14 informative cases showed losses compared with 3 of 8 cases without field disease. A more pronounced deletion of TP53 (P = 0.002) and RB1 (P = 0.02) was found in the progressing tumor group compared with the recurrent noninvasive group, and, finally, the combined loss of TP53 and RB1 was present only in the progressing tumor or muscle-invasive groups. Deletion of two or more loci in TP53, MYCL, RB1, and CDKN2A was found in 10 patients in the progressing tumor group and in only 1 patient in the recurrent noninvasive group (P = 0.004). The data demonstrate that a characteristic difference between recurrent noninvasive and recurrent progressing bladder tumors is loss of cell cycle-regulatory genes in the latter group.

Specificity and immunobiological properties of monoclonal antibody IMH2, established after immunization with Le(b)/Le(a) glycosphingolipid, a novel extended type 1 chain antigen.

Extended lacto-series type 1 chain antigens lacking type 2 chain core have recently been shown to comprise a new type of tumor-associated carbohydrate antigen. Examples are Le(a)/Le(a) (IV3Gal beta 1----3[Fuc alpha 1----4]Glc-NAcLc4Cer) and Le(b)/Le(a) (IV3Fuc alpha 1----2Gal beta 1----3[Fuc alpha 1----4]Glc-NAcLc4Cer) (M. R. Stroud, et al., J. Biol. Chem., 266: 8439-8446, 1991; Eur. J. Biochem., 203: 577-586, 1992). We have now established an IgG3 mouse monoclonal antibody (IMH2) after immunization of mice with Le(b)/Le(a) antigen; however, monoclonal antibody (MAb) IMH2 reacted not only with the immunogen used but also with Le(y)/Le(x) and to a lesser degree with short-chain Le(y) or Le(b) with hexasaccharide ceramide (i.e., IV2FucIII3FucnLc4Cer or IV2FucIII4FucLc4Cer). It showed a high incidence of staining and strong reactivity with carcinomas of colon, rectum, liver, pancreas, and endometrium, but no reactivity with normal colonic mucosa at various loci, and minimal reactivity with normal liver, pancreas, or uterine endometrium. On the other hand, it reacted with normal gastric mucosa, cecal mucosa, urothelium, adrenal glands, and thymus. Its expression in colorectal tumors and normal cecal tissue was independent of secretor status, whereas that in normal urothelium was dependent on secretor status. MAb IMH2 displayed strong lymphocyte-activated or complement-dependent killing of human colonic cancer Colo205 cells in vitro, and inhibition of Colo205 growth in vivo; this inhibition was comparable to that by MAb NCC-ST-421, which is directed to Le(a)/Le(a) epitope (M. Watanabe, et al., Cancer Res., 51:2199, 1991). These results indicate that a new extended type 1 chain structure, Le(b)/Le(a), is a useful tumor marker associated with carcinomas of colon, rectum, pancreas, liver, and endometrium and that MAb IMH2 has potential diagnostic or therapeutic applicability for these carcinomas.