Differential expression of trypsinogen and tumor-associated trypsin inhibitor (TATI) in bladder cancer.

Tumor-associated trypsin inhibitor (TATI) is a marker of mucinous ovarian carcinoma, but it is also widely expressed in other malignant tumors and normal human tissues. Elevated serum concentrations of TATI are of prognostic value in ovarian, kidney, and bladder cancer. Tumor-associated trypsin is co-expressed with TATI in many malignancies and is thought to be involved in tumor invasion. TATI mRNA has been shown to be overexpressed in bladder cancer. We therefore studied whether trypsinogen expression also can be detected in bladder cancer and how this and TATI expression are associated with the clinicopathological characteristics of the tumors. We used RT-PCR, in situ hybridization and immunohistochemistry to detect trypsinogen- and TATI mRNA and protein in tissue samples from 28 bladder cancer patients and ten benign urothelia. TATI expression was detected in all benign tissues and non-invasive tumors. However, the expression was lower in the muscle-invasive tumors (pT2; n=5), whereas trypsinogen expression was seen in all but one non-invasive tumor. We conclude that trypsinogen is expressed in both malignant and benign bladder epithelium, whereas TATI expression decreases with increasing stage and grade of the tumor. This may suggest that a balanced expression of TATI and trypsinogen is required in normal tissue and that this balance is disrupted during tumor progression.

Inflammation and cytokeratin 7/20 staining of cardiac mucosa in young patients with and without Helicobacter pylori infection.

BACKGROUND: Both Helicobacter pylori and gastro-oesophageal reflux disease (GORD) may cause inflammation in cardiac mucosa. Intestinal metaplasia (IM) is found more often in GORD associated inflammation than in inflammation caused by H pylori, especially in young individuals. AIM: To examine morphological differences in chronic inflammation in these two conditions by immunohistochemistry. PATIENTS/METHODS: Tissue blocks from cardiac mucosa of patients <45 years were available as follows: 10 patients with chronic inflammation of cardiac mucosa (carditis) and H pylori gastritis (group 1); 10 patients with (possibly GORD related) carditis, but normal antrum and corpus (group 2); and 10 patients with non-inflamed cardiac mucosa and normal antrum and corpus (group 3). Haematoxylin and eosin staining and immunohistochemical staining for various inflammatory cells were performed for patients in groups 1 and 2 as follows: CD20 (B cells), CD3 (T cells), CD4 (T helper cells), CD8 (T suppressor cells), CD163 (macrophages), CD138 (plasma cells), and CD117 (mast cells). For all patients, cytokeratin 7/20 (CK7/20) staining was performed. RESULTS: No clear differences were seen in the morphology of chronic inflammation between groups 1 and 2. In both, plasma cells were most abundant. CK7/20 staining showed no differences between these groups. CONCLUSION: Helicobacter pylori negative (possibly GORD associated) and H pylori related carditis cannot be distinguished on a morphological basis. The stronger tendency towards IM in the first entity cannot be explained by differences in the type of inflammation. Barrett-type CK7/20 staining seems typical for cardiac mucosa, irrespective of the type of inflammation or presence of IM.

Systematic knockdown of epigenetic enzymes identifies a novel histone demethylase PHF8 overexpressed in prostate cancer with an impact on cell proliferation, migration and invasion.

Our understanding of key epigenetic regulators involved in specific biological processes and cancers is still incomplete, despite great progress in genome-wide studies of the epigenome. Here, we carried out a systematic, genome-wide analysis of the functional significance of 615 epigenetic proteins in prostate cancer (PrCa) cells. We used the high-content cell-spot microarray technology and siRNA silencing of PrCa cell lines for functional screening of cell proliferation, survival, androgen receptor (AR) expression, histone methylation and acetylation. Our study highlights subsets of epigenetic enzymes influencing different cancer cell phenotypes. Plant homeo domain (PHD) finger proteins have a key role in cell survival and histone methylation, whereas histone deacetylases were primarily involved in regulating AR expression. In contrast, JumonjiC-domain (JmjC) containing histone lysine demethylases (KDMs) mainly had an impact on cell proliferation. Our results show that the KDMs JARID1B, PHF8, KDM3A, KDM3B and KDM4A were highly expressed in clinical PrCa samples. The PHD-finger protein 8 (PHF8), a transcriptional coactivator with both PHD- and JmjC-domains, was moderately to strongly expressed in 80% of clinical PrCa samples, whereas 76% of normal and benign samples were negative or only showed weak PHF8 expression. Strong PHF8 expression correlated significantly with high Gleason grade and was borderline significant for poor prognosis. The results of functional PHF8 knockdown implicate a role in cell migration and invasion, as shown by cell motility and 3-D invasion assays. Our study suggests that various cellular phenotypes are regulated by distinct subsets of epigenetic enzymes. Proteins interpreting and modifying histone methylation, such as JmjC-domain and particularly PHD-finger proteins like PHF8, are activated in subsets of PrCa's and promote cancer relevant phenotypes.

APC mutations in sporadic medulloblastomas.

The cerebellar medulloblastoma (WHO Grade IV) is a highly malignant, invasive embryonal tumor with preferential manifestation in children. Several molecular alterations appear to be involved, including isochromosome 17q and the p53, PTCH, and beta-catenin gene mutations. In this study, 46 sporadic medulloblastomas were screened for the presence of mutations in genes of the Wnt signaling pathway (APC and beta-catenin). Single-strand conformational polymorphism (SSCP) analysis followed by direct DNA sequencing revealed 3 miscoding APC mutations in 2 (4.3%) medulloblastomas. One case contained a GCA-->GTA mutation at codon 1296 (Ala-->Val), and another case had double point mutations at codons 1472 (GTA-->ATA, Val-->Ile) and 1495 (AGT-->GGT, Ser-->Gly). Miscoding beta-catenin mutations were detected in 4 tumors (8.7%). Three of these were located at codon 33 (TCT -->TTT, Ser-->Phe) and another at codon 37 (TCT-->GCT, Ser-->Ala). Adenomatous polyposis coli (APC) gene and beta-catenin mutations were mutually exclusive and occurred in a total of 6 of 46 cases (13%). Although germline APC mutations are a well established cause of familial colon and brain tumors (Turcot syndrome), this study provides the first evidence that APC mutations are also operative in a subset of sporadic medulloblastomas.

Beta-catenin mutations are frequent in human hepatocellular carcinomas associated with hepatitis C virus infection.

Hepatocellular carcinoma (HCC) is one of the most common fatal cancers worldwide. Hepatitis B virus and hepatitis C virus infections, exposure to aflatoxin, and excessive intake of alcohol have been identified as major risk factors. However, the molecular mechanisms underlying their development are still poorly understood. Recently, beta-catenin, one of the key components of the Wnt signaling pathway, has been found to be mutated in about 20% of HCCs, suggesting a role of the Wnt pathway in their development. In this study, we examined beta-catenin and APC mutations in 22 HCCs associated with HCV infection, using single-strand conformation polymorphism (SSCP) followed by direct DNA sequencing. beta-Catenin mutations were found in nine (41%) cases, but no APC mutations were found. beta-Catenin immunohistochemistry revealed nuclear accumulation of beta-catenin protein in all nine tumors with a beta-catenin mutation and two additional tumors without a mutation. These results suggest that activation of the Wnt signaling pathway by beta-catenin mutation contributes significantly to the hepatocellular carcinogenesis associated with HCV infection.