Tumor budding is a histological feature that reflects loss of adhesion of tumor cells and is associated with locoregional metastasis of colorectal carcinoma. Although nuclear localization of ...β-catenin is associated with tumor budding, the molecular mechanism remains largely elusive. In this study, we hypothesize that the epithelial cell adhesion molecule (Ep-CAM) is involved in tumor budding. In order to address this question, we performed immunohistochemistry on Ep-CAM using three different antibodies (monoclonal antibodies Ber-ep4 and 311-1K1 and a polyclonal antibody) and a double staining on β-catenin and Ep-CAM. In addition, Ep-CAM mRNA was monitored with mRNA in situ hybridization. Subsequently, we determined the effect of Ep-CAM staining patterns on tumor spread in rectal cancer. In contrast to the tumor mass, budding cells of colorectal carcinoma displayed lack of membranous but highly increased cytoplasmic Ep-CAM staining and nuclear translocation of β-catenin. mRNA in situ hybridization suggested no differences in Ep-CAM expression between the invasive front and the tumor mass. Importantly, reduced Ep-CAM staining at the invasive margin of rectal tumor specimens (n=133) correlated significantly with tumor budding, tumor grade and an increased risk of local recurrence (P=0.001, P=0.04 and P=0.03, respectively). These data demonstrate abnormal processing of Ep-CAM at the invasive margin of colorectal carcinomas. Our observations indicate that loss of membranous Ep-CAM is associated with nuclear β-catenin localization and suggest that this contributes to reduced cell–cell adhesions, increased migratory potential and tumor budding.
Activated signal transducer and activator of transcription 3 (STAT3) regulates tumor growth, invasion, cell proliferation, angiogenesis, immune response, and survival. Data regarding expression of ...phosphorylated (activated) STAT3 in diffuse large B-cell lymphoma (DLBCL) and the impact of phosphorylated STAT3 (pSTAT3) on prognosis are limited.
We evaluated expression of pSTAT3 in de novo DLBCL using immunohistochemistry, gene expression profiling (GEP), and gene set enrichment analysis (GSEA). Results were analyzed in correlation with cell-of-origin (COO), critical lymphoma biomarkers, and genetic translocations.
pSTAT3 expression was observed in 16% of DLBCL and was associated with advanced stage, multiple extranodal sites of involvement, activated B-cell-like (ABC) subtype, MYC expression, and MYC/BCL2 expression. Expression of pSTAT3 predicted inferior overall survival (OS) and progression-free survival (PFS) in patients with de novo DLBCL. When DLBCL cases were stratified according to COO or MYC expression, pSTAT3 expression did not predict inferior outcome, respectively. Multivariate analysis showed that the prognostic predictability of pSTAT3 expression was due to its association with the ABC subtype, MYC expression, and adverse clinical features. GEP demonstrated upregulation of genes, which can potentiate function of STAT3. GSEA showed the JAK-STAT pathway to be enriched in pSTAT3(+) DLBCL.
The results of this study provide a rationale for the ongoing successful clinical trials targeting the JAK-STAT pathway in DLBCL.
AKT signaling is important for proliferation and survival of tumor cells. The clinical significance of AKT activation in diffuse large B-cell lymphoma (DLBCL) is not well analyzed. Here, we assessed ...expression of phosphorylated AKT (p-AKT) in 522 DLBCL patients. We found that high levels of p-AKT nuclear expression, observed in 24.3% of the study cohort, were associated with significantly worse progression-free survival and Myc and Bcl-2 overexpression. However, multivariate analysis indicated that AKT hyperactivation was not an independent factor. miRNA profiling analysis demonstrated that 63 miRNAs directly or indirectly related to the phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin pathway were differentially expressed between DLBCLs with high and low p-AKT nuclear expression. We further targeted AKT signaling using a highly selective AKT inhibitor MK-2206 in 26 representative DLBCL cell lines and delineated signaling alterations using a reverse-phase protein array. MK-2206 treatment inhibited lymphoma cell viability, and MK-2206 sensitivity correlated with AKT activation status in DLBCL cells. On MK-2206 treatment, p-AKT levels and downstream targets of AKT signaling were significantly decreased, likely because of the decreased feedback repression; Rictor and phosphatidylinositol 3-kinase expression and other compensatory pathways were also induced. This study demonstrates the clinical and therapeutic implications of AKT hyperactivation in DLBCL and suggests that AKT inhibitors need to be combined with other targeted agents for DLBCL to achieve optimal clinical efficacy.
Overlap in the clinical presentation of pediatric granulomatous inflammatory bowel disease may be substantial, depending on the mode of presentation. Chronic granulomatous disease (CGD) may present ...with granulomatous colitis, perianal abscesses, hepatic abscesses or granulomas, failure to thrive, and obstruction of the gastrointestinal tract (including esophageal strictures and dysmotility, delayed gastric emptying, and small bowel obstruction). Anemia, thrombocytosis, elevated C-reactive protein and erythrocyte sedimentation rate, and hypoalbuminemia are nonspecific and may occur in any of the granulomatous inflammatory bowel diseases. In histology, macrophages with cytoplasmic inclusions will be rather specific for CGD. Sarcoidosis may present with abdominal pain or discomfort, diarrhea, weight loss, growth failure, delayed puberty, erythema nodosum, arthritis, uveitis, and hepatic granulomata. Only in 55% of the patients will angiotensin-converting enzyme be elevated. The noncaseating epithelioid granulomata will be unspecific. Bronchoalveolar lymphocytosis and abnormalities in pulmonary function are reported in sarcoidosis and in Crohn disease (CD) and CGD. Importantly, patients with CD may present with granulomatous lung disease, fibrosing alveolitis, and drug-induced pneumonitis. Sarcoidosis and concomitant gastrointestinal CD have been reported in patients, as well as coexistence of CD and sarcoidosis in siblings. Common susceptibility loci have been identified in CD and sarcoidosis. CD and CGD share defects in the defense mechanisms against different microbes. In the present review, common features and essential differences are discussed in clinical presentation and diagnostics--including histology--in CGD, sarcoidosis, and CD, together with 2 other granulomatous inflammatory bowel diseases, namely abdominal tuberculosis and Hermansky-Pudlak syndrome. Instructions for specific diagnosis and respective treatments are provided.
Tumor evaluation in pathology is more and more based on a combination of traditional histopathology and molecular analysis. Due to the rapid development of new cancer treatments that specifically ...target aberrant proteins present in tumor cells, treatment decisions are increasingly based on the molecular features of the tumor. Not only the number of patients eligible for targeted precision medicine, but also the number of molecular targets per patient and tumor type is rising. Diagnostic molecular pathology, the discipline that determines the molecular aberrations present in tumors for diagnostic, prognostic or predictive purposes, is faced with true challenges. The laboratories have to meet the need of comprehensive molecular testing using only limited amount of tumor tissue, mostly fixed in formalin and embedded in paraffin (FFPE), in short turnaround time. Choices must be made for analytical methods that provide accurate, reliable and cost-effective results. Validation of the test procedures and results is essential. In addition, participation and good performance in internal (IQA) and external quality assurance (EQA) schemes is mandatory. In this review, we critically evaluate the validation procedure for comprehensive molecular tests as well as the organization of quality assurance and assessment of competence of diagnostic molecular pathology laboratories within Europe.
•Molecular pathology testing should be performed in ISO 15189-accredited laboratories.•Appropriately educated and dedicated personnel are essential.•One dedicated organization that coordinates all EQA schemes will improve efficiency.•The actions for laboratories after poor performance need standardization.
Testing for treatment related biomarkers in clinical care, like
Ras
mutation status in colorectal cancer (CRC), has increased drastically over recent years. Reliable testing of these markers is ...pivotal for optimal treatment of patients. Participation in external quality assessment (EQA) programs is an important element in quality management and often obligatory to comply with regulations or for accreditation. Formalin-fixed paraffin-embedded (FFPE) clinical specimens would ideally form the basis for these assessments, as they represent the most common starting material for molecular testing. However, molecular heterogeneity of a lesion in a FFPE tissue block could potentially affect test results of participating laboratories, which might compromise reliability of the quality assessment results. To assess the actual impact of this potential problem, we determined the mutation status of 22 genes commonly mutated in colon cancer in four levels covering 360 μm of 30 FFPE tissue blocks, by Next Generation Sequencing. In each block, the genotype of these genes was identical at all four levels, with only little variation in mutation load. This result shows that the mutation status of the selected 22 genes in CRC specimens is homogeneous within a 360 μm segment of the tumor. These data justify the use of serial sections, within a defined segment of a CRC tissue block, for external quality assessment of mutation analysis.
Multiple studies have demonstrated that diffuse large B-cell lymphoma (DLBCL) can be divided into subgroups based on their biology; however, these biological subgroups overlap clinically. Using ...machine learning, we developed an approach to stratify patients with DLBCL into four subgroups based on survival characteristics. This approach uses data from the targeted transcriptome to predict these survival subgroups. Using the expression levels of 180 genes, our model reliably predicted the four survival subgroups and was validated using independent groups of patients. Multivariate analysis showed that this patient stratification strategy encompasses various biological characteristics of DLBCL, and only TP53 mutations remained an independent prognostic biomarker. This novel approach for stratifying patients with DLBCL, based on the clinical outcome of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone therapy, can be used to identify patients who may not respond well to these types of therapy, but would otherwise benefit from alternative therapy and clinical trials.
Autosomal dominant hereditary diffuse gastric cancer (HDGC) is caused by germ-line E-cadherin (CDH1) gene mutations. Early detection of cancer in carriers is difficult because HDGC escapes endoscopic ...detection. We hypothesized that the glucose metabolism is enhanced in HDGC and that this can be detected with 18Ffluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET).
An asymptomatic twenty-eight year-old female was seen at our outpatient clinic because of a request for screening on HDGC. Her father and younger sister died of diffuse gastric cancer, at the ages of 52 and 27, respectively. Mutational analysis of the CDH1 gene in this patient demonstrated a novel heterozygous splice-site mutation in exon 8 (1135delACGGTAATinsTTAGA). Upper gastrointestinal endoscopies revealed no macroscopic abnormalities, but one of the 40 random biopsy specimens showed well-differentiated signet-cell carcinoma. A FDG-PET scan demonstrated two spots of FDG accumulation, one located in the proximal part of the stomach and the second in the region of the pylorus. A total gastrectomy was performed and microscopic examination showed focal localization of intramucosal adenocarcinoma of the signet-cell type in the cardiac and antrum area. Most notably, the localization of the FDG accumulation matched the localization of the carcinoma.
We present an asymptomatic patient from a HDGC family carrying a novel CDH1 mutation in whom FDG-PET scanning facilitated early detection of HDGC. This calls for further investigation of the role of FDG-PET scan as a screening modality in HDGC.
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