Immunohistochemical Staining For Beta-catenin Research Articles

Sporadic, Nontrauma-Related, Desmoid Tumor of the Pancreas: A Rare Disease—Case Report and Literature Review

Desmoid tumors (DTs) are neoplasms of fibroblastic origin characterized by lack of a capsule. They are nonmetastatic and locally aggressive. Intraabdominal DTs are often observed in familial adenomatous polyposis and Gardner syndrome or subsequent to localized traumatic injury. Sporadic forms are defined as nontrauma- or nongenetic-related DTs. Isolated, sporadic pancreatic DTs have been considered anecdotal, with only 9 cases described in the literature. We report the case of a 68-year-old man with a case of sporadic cystic DT localized to the pancreatic tail. The tumor was discovered incidentally during computerized tomography performed for an unrelated condition. The patient was asymptomatic; however, biopsy was performed on the clinical suspicion of cystic cancer of the pancreas. Pathology analysis showed fibroblastic proliferation, and the diagnosis of DT was confirmed by immunohistochemical staining for beta-catenin. The patient underwent resection with no further treatment and remain disease-free 60 months after surgery.

Wnt pathway in pulmonary fibrosis in the bleomycin mouse model.

The Wnt/beta-catenin signaling pathway plays an important role in regulating cellular differentiation, proliferation, and polarity. We used bleomycin to induce lung fibrosis in a transgenic Wnt reporter mouse to characterize the expression pattern of cyclin D1, MMP-7, and TGF-beta in conjunction with the Wnt/beta-catenin signaling pathway. LacZ expression reveals the Wnt/beta-catenin signaling pathway through the activated (nuclear) beta-catenin and coactivation of LEF/TCF transcription factors. X-gal staining and immunohistochemical staining of beta-catenin, cyclin D1, MMP-7, and TGF-beta were assessed after bleomycin administration. We observed LacZ expression in bronchiolar proliferative lesions and the epithelium in remodeled cystic and fibrotic areas at both 1 and 3 weeks. Nuclear beta-catenin staining was prominent in epithelial cells of remodeled and fibrotic areas at 3 weeks. MMP-7 was faint in basement membranes of airways and matrix zones in fibrotic areas at 3 weeks. Cyclin D1 was observed in alveolar macrophages (AM), alveolar epithelium, and fibrotic areas consistent with rapid cell turnover in these areas at both 1 and 3 weeks. TGF-beta was faintly staining in alveolar macrophages and epithelial cells at 3 weeks. The Wnt/beta-catenin pathway is activated in bleomycin-induced lung fibrosis, and downstream genes were localized in AM, alveolar epithelium, and interstitium.

Disturbed expression of E‐cadherin, beta‐catenin and tight junction proteins in colon carcinoma is unrelated to growth pattern and genetic polymorphisms

Adhesion proteins are responsible for the structural integrity of epithelial tissue and in tumors this integrity is often lost, resulting in a disorganization of the tissue. In the present study the complexity of the invasive front of colon carcinomas was correlated with cell adhesion protein expression and with polymorphisms in their genes. A complexity index was constructed from 32 colon carcinomas using computer-assisted morphometry estimating fractal dimension and tumor cell clusters followed by tree analysis. Immunohistochemical staining of beta-catenin, E-cadherin, occludin and claudin 2 was used for assessment of protein expression. Genetic screening of tissue from the tumor invasion front with laser microdissection was performed using SSCP and DNA sequencing. Adhesion protein distribution was significantly disturbed in most carcinomas. A single mutation in the gene of beta-catenin was found but there was no correlation between protein expression and genetic polymorphism. Nor was there any correlation between the complexity of the invasive border and protein distribution or genetic alterations. The results indicate that the complexity of colon carcinoma invasion is not dependent on genetic derangements in the genes of adhesion proteins or the protein distribution. Rather, aberrations in the function of other proteins related to the adhesive proteins could be responsible.

Nuclear β-Catenin Accumulation as Reliable Marker for the Differentiation Between Cystic Craniopharyngiomas and Rathke Cleft Cysts: A Clinico-Pathologic Approach

Clinical and histopathologic differentiation of cystic lesions from the sellar region, that is, craniopharyngiomas (CPs) and Rathke cleft cysts (RCCs), is challenging and has paramount importance with respect to variable clinical manifestation and adapted surgical treatment strategies in both entities. Here, we retrospectively evaluated clinico-pathologic findings in 81 patients presenting with a cystic tumor located in the sellar region. All patients underwent transsphenoidal or transcranial resections. Microscopic inspection of surgical specimens identified CP in 51 patients, and RCC in 30 patients. Amongst the panel of immunohistochemical marker proteins used for histopathologic analysis, nuclear accumulation of beta-catenin was detectable only in CP. On the basis of the histopathologic and immunohistochemical analysis, clinical presentation (sex, age, ophthalmologic, and endocrinologic deficits), imaging (tumor location, size, and calcification), as well as a description of cyst contents obtained during operation were retrospectively evaluated. In purely cystic CPs, an isointense signal was more frequent in T1-weighted magnetic resonance images and calcification of the tumor capsule in computed tomography scans. In addition, the size of RCC was smaller and this tumor entity was more often located within the sella. Aberrant (nuclear) immunohistochemical staining for beta-catenin appeared, however, as most reliable factor for the differentiation between purely cystic CPs and RCCs, whereas tumor location, tumor size, and calcification of the tumor capsule were less consistent parameters. The data are compatible with distinct pathogenic pathways associated with these related histopathologic entities.

Accumulation of β‐catenin protein, mutations in exon‐3 of the β‐catenin gene and a loss of heterozygosity of 5q22 in solid pseudopapillary tumor of the pancreas

Solid pseudopapillary tumors (SPT) of the pancreas are neoplasms with a low malignant potential. The molecular events contributing to the pathogenesis of SPTs are still unknown. This study was intended to help better understand the early steps of human SPT development. We microdissected 20 SPTs and normal pancreatic tissue. In addition, we examined the DNA from each SPT for mutations in exon-3 of beta-catenin and loss of heterozygosity (LOH) on 9 chromosome arms using 10 microsatellite markers. Immunohistochemical staining for beta-catenin was performed. Activating mutations between codons 32 and 37 of beta-catenin exon-3 were present in 16 cases (80%). Allelic loss on chromosome 5q22.1 was present in 10 cases (55.5%), while no allelic loss was found on chromosomes 1p, 6q, 9p, 9q, 11p, 11q, 17p, or 22q. Nuclear accumulation of beta-catenin was found in 20 cases (100%). Mutations in exon-3 of the beta-catenin gene, nuclear accumulation of beta-catenin, and LOH on chromosome 5q22.1 in SPT tissue suggest that these mutations are involved in SPT tumorigenesis.

False-Negative Hybrid Capture II Results Related to Altered Adhesion Molecule Distribution in Women with Atypical Squamous Cells Pap Smear Results and Tissue-Based Human Papillomavirus-Positive High-Grade Cervical Intraepithelial Neoplasia

We investigated the detection of high-risk human papillomavirus DNA with the Hybrid Capture II test (HCII; Digene Corporation, Beltsville, MD) and the presence and pattern of distribution of adhesion molecules in biopsy-proven high-grade neoplastic lesions containing high-risk HPV-DNA from women with ASC cytology results. We screened 4,600 women and performed colposcopy in 278 women with atypical squamous cells cytologic results. All women underwent HCII and tissue-based polymerase chain reaction analysis for high-risk HPV subtypes. Of 33 women with cervical intraepithelial neoplasia (CIN) 2 or worse biopsy results, 27 biopsy specimens contained sufficient tissue to perform immunohistochemical testing (pathologist blinded as to cytologic and HCII results) for adhesion molecules beta-catenin and 21 cases for E-cadherin. Five of 27 specimens with CIN 2 or worse biopsy results (18.5%) had negative HCII results. All five specimens showed evidence of high-risk human papillomavirus by polymerase chain reaction analysis. All five showed full-thickness distribution via immunohistochemical staining for beta-catenin. There was sufficient tissue to examine four of five specimens for E-cadherin, and a full-thickness distribution also was documented. Previous research linked false-negative cytologic results in women with high-grade CIN to altered adhesion molecule distribution and impaired exfoliation, and a similar phenomenon may be responsible for false-negative HCII results in women with atypical squamous cells cytologic results and high-grade CIN.

A novel mouse model for colitis-associated colon carcinogenesis induced by 1,2-dimethylhydrazine and dextran sulfate sodium.

To develop an efficient animal colitis-associated carcinogenesis model and to detect the expression of beta-catenin and p53 in this new model. Dysplasia and cancer were investigated in mice pretreated with a single intraperitoneal injection of 20 mg/kg body mass of 1,2-dimethylhydrazine prior to three repetitive oral administrations of 30 g/L dextran sulfate sodium to give conditions similar to the clinically observed active and remission phases. Immunohistochemical staining of beta-catenin and p53 was performed on paraffin-imbedded specimens of animals with cancer and/or dysplasia, those without dysplasia and the normal control animals. At wk 11, four early-invasive adenocarcinomas and 36 dysplasia were found in 10 (90.9%) of the 11 mice that underwent 1,2-dimethylhydrazine-pretreatment with 3 cycles of 30 g/L dextran sulfate sodium-exposure. Dysplasia and/or cancer occurred as flat lesions or as dysplasia-associated lesion or mass (DALM) as observed in humans. Colorectal carcinogenesis occurred primarily on the distal portion of the large intestine. No dysplasia and/or cancer lesion was observed in the control groups with 1,2-dimethylhydrazine pretreatment or 3 cycles of 30 g/L dextran sulfate sodium exposure alone. Immunohistochemical investigation revealed that beta-catenin was translocated from cell membrane to cytoplasm and/or nucleus in 100% of cases with dysplasia and neoplasm, while normal membrane staining was observed in cases without dysplasia and the normal control animals. Nuclear expression of p53 was not detected in specimens. A single dose of procarcinogen followed by induction of chronic ulcerative colitis results in a high incidence of colorectal dysplasia and cancer. Abnormal expression of beta-catenin occurs frequently in dysplasia and cancer. This novel mouse model may provide an excellent vehicle for studying colitis-related colon carcinogenesis.

Role of Wnt pathway in medulloblastoma oncogenesis.

To clarify the roles of Wnt pathway in medulloblastoma oncogenesis, immunohistochemical staining of beta-catenin and Wnt-1 and genomic analyses of CTNNB1 (beta-catenin) and AXIN1 (axin 1) were examined in 23 sporadic cases. Accumulation of beta-catenin in tumor cells was immunohistochemically proven in 5 cases; 2 cases showed positive immunoreactivity for Wnt-1 and another 2 showed mutation of either CTNNB1 or AXIN1. AXIN1 mutation was in exon 3, corresponding to GSK-3beta binding site and CTNNB1 mutation was in exon 3, corresponding to its phosphorylation site. Disruption of these proteins could result in upregulation of the Wnt signaling and accumulation of beta-catenin, followed by cell proliferation and medulloblastoma oncogenesis.

Reduced E-cadherin expression as a cause of distinctive signet-ring cell variant in colorectal carcinoma.

Colorectal signet-ring cell carcinoma (SRCC) is a rare type of adenocarcinoma and presents with distinctive clinicopathological features. This study was performed to assess the biological characteristics of colorectal SRCC regarding the E-cadherin expression. Seventeen patients with primary colorectal SRCC were identified and their clinicopathological characteristics were analyzed. The mean age of the 17 patients was 45.3 yr (14-68). Immunohistochemical staining of E-cadherin and beta-catenin were performed in ten colorectal SRCCs and in 30 ordinary colorectal adenocarcinomas as control. Primary colorectal SRCC occurred in 0.7% of 2,388 colorectal adenocarcinomas. Most patients had advanced stage tumor at surgery (stage III and IV, AJCC: 82%). Five-year survival rate was 16%. Peritoneal seeding was the most common recurrence pattern (41%) and liver metastasis was not identified. All SRCCs showed a markedly reduced or absent expression of E-cadherin on immunohistochemical staining, whereas seven (23.3%) of ordinary carcinomas showed reduced expression, thereby indicating a significant difference between the two groups (p<0.005). In immunohistochemical staining for beta-catenin, eight of ten SRCCs showed reduced membrane expression that did not attain statistical significance compared to ordinary adenocarcinomas. It is suggested that aberrant E-cadherin expression may explain the distinct clinicopathological features in primary colorectal SRCC.