Comprehensive characterization of a Canadian cohort of von Hippel-Lindau disease patients

Von Hippel-Lindau disease (VHL) is a heritable condition caused by pathogenic variants in VHL and is characterized by benign and malignant lesions in the central nervous system (CNS) and abdominal viscera. Due to its variable expressivity, existing efforts to collate VHL patient data do not adequately capture all VHL manifestations. We developed a comprehensive and standardized VHL database in the web-based application, REDCap, that thoroughly captures all VHL manifestation data. As an initial trial, information from 86 VHL patients from the University Health Network/Hospital for Sick Children was populated into the database. Analysis of this cohort showed missense variants occurring with the greatest frequency, with all variants localizing to the α- or β-domains of VHL. The most prevalent manifestations were central nervous system (CNS), renal, and retinal neoplasms, which were associated with frameshift variants and large deletions. We observed greater age-related penetrance for CNS hemangioblastomas with truncating variants compared to missense, while the reverse was true for pheochromocytomas. We demonstrate the utility of a comprehensive VHL database, which supports the standardized collection of clinical and genetic data specific to this patient population. Importantly, we expect that its web-based design will facilitate broader international collaboration and lead to a better understanding of VHL.     

The clinical utility of miR-21 as a diagnostic and prognostic marker for renal cell carcinoma

Renal cell carcinoma (RCC) is the most common neoplasm of the kidney. Increasing evidence suggests that microRNAs are dysregulated in RCC and are important factors in RCC pathogenesis. miR-21 is a known oncogene with tumor-promoting effects in many types of cancer. In this study, we analyzed miR-21 in 121 cases of healthy kidney and different RCC subtypes, including clear cell (ccRCC), papillary (pRCC), chromophobe (chRCC), and oncocytoma. Total RNA was extracted, and the expression of miR-21 was measured with real-time quantitative RT-PCR using miR-21-specific probes. The expression of miR-21 was significantly up-regulated in RCC compared with healthy kidney. There was a significant difference in the expression levels between RCC subtypes, with the highest levels of expression in ccRCC and pRCC subtypes. miR-21 expression distinguished ccRCC and pRCC from chRCC and oncocytoma with 90% specificity (95% CI, 63.9% to 98.1%) and 83% sensitivity (95% CI, 53.5% to 97.6%). Significantly higher miR-21 levels were associated with higher stage and grade. Patients who were miR-21 positive had statistically significant shorter disease-free and overall survival rates. Thus, miR-21 is up-regulated in RCC, and its expression levels can be used as a diagnostic marker to distinguish ccRCC and pRCC from chRCC and oncocytoma. Moreover, it has potential as a prognostic marker in RCC, although it is not independent of tumor stage and grade.     

miRNAs dysregulated in association with Gleason grade regulate extracellular matrix,cytoskeleton and androgen receptor pathways

The Gleason grading system is an important determinant of treatment decisions and prognosis in prostate cancer. It has a number of limitations, including significant inter‐observer variability, creating a need for biological parameters to accurately assess the Gleason grade. The objective of this study was to determine the molecular correlates of the different Gleason grades. Global miRNA expression was analysed in pure regions of each Gleason grade. Bioinformatics analysis was performed to predict miRNA‐mediated signalling. We experimentally validated the effect of miRNAs on target gene expression and cellular functions using cell line models. We also examined the correlation of miRNAs with biochemical failure, metastasis and prognosis. We identified miRNAs that are differentially expressed between grades 3 and 5, and the top biological processes associated with Gleason grade transition were extracellular matrix (ECM)‐mediated signalling, focal adhesion kinase‐ and mitogen‐activated kinase pathways. Transfection with miR‐29c, miR‐34a and miR‐141 repressed genes involved in ECM‐mediated pathways, such as SRC, PRKCA, COL1A1, ITGB1 and MAPK13, and decreased cell proliferation and migration. Furthermore, miR‐29c and miR‐34a influenced downstream pathways that affect actin cytoskeleton organization and androgen receptor localization. Finally, miR‐29c, miR‐34a, miR‐141 and miR‐148a showed inverse correlations with biochemical recurrence, but were independent of other clinical parameters. Our results demonstrate the potential role of miRNAs as independent prognostic markers and pave the road for a biological‐based reclassification of the Gleason grading system. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Prognostic role and implications of mutation status of tumor suppressor gene ARID1A in cancer: a systematic review and meta-analysis

Loss of the tumor suppressor gene AT-rich interactive domain-containing protein 1A (ARID1A) has been demonstrated in several cancers, but its prognostic role is unknown. We aimed to investigate the risk associated with loss of ARID1A (ARID1A−) for all-cause mortality, cancer-specific mortality and recurrence of disease in subjects with cancer. PubMed and SCOPUS search from database inception until 01/31/2015 without language restriction was conducted, contacting authors for unpublished data. Eligible were prospective studies reporting data on prognostic parameters in subjects with cancer, comparing participants with presence of ARID1A (ARID1A+) vs. ARID1A−, assessed either via immunohistochemistry (loss of expression) or with genetic testing (presence of mutation). Data were summarized using risk ratios (RR) for number of deaths/recurrences and hazard ratios (HR) for time-dependent risk related to ARID1A− adjusted for potential confounders. Of 136 hits, 25 studies with 5,651 participants (28 cohorts; ARID1A−: n = 1,701; ARID1A+: n = 3,950), with a mean follow-up period of 4.7 ± 1.8 years, were meta-analyzed. Compared to ARID1A+, ARID1A− significantly increased cancer-specific mortality (studies = 3; RR = 1.55, 95% confidence interval (CI) = 1.19–2.00, I² = 31%). Using HRs adjusted for potential confounders, ARID1A− was associated with a greater risk of cancer-specific mortality (studies = 2; HR = 2.55, 95%CI = 1.19–5.45, I² = 19%) and cancer recurrence (studies = 10; HR = 1.93, 95%CI = 1.22–3.05, I² = 76%). On the basis of these results, we have demonstrated that loss of ARID1A shortened time to cancer-specific mortality, and to recurrence of cancer when adjusting for potential confounders. For its role, this gene should be considered as an important potential target for personalized medicine in cancer treatment.     

Über die verschiedene Empfindlichkeit der rechten und linken Herzkammermuskulatur gegenüber Hypoxie

Zusammenfassung In Hypoxie wird die linke Herzkammer am nachLangendorff isolierten Herzen, und auch am Herz-Lungen-Präparat bzw. am Herzen in situ, früher und in größerem Maße insuffizient, als die rechte Kammer. Auf der Suche nach einer Erklärung dieses Phänomens konnte festgestellt werden, daß die in vitro Sauerstoffaufnahme der linken Kammermuskulatur in signifikanter Weise höher liegt, als die der rechten. Verschiedene Möglichkeiten zur Erklärung dieser Befunde werden besprochen.Mit 6 Abbildungen in 20 Einzeldarstellung und 6 TabellenEine vorläufige Mitteilung über die Ergebnisse wurde auf der XVII. Tagung der Ungarischen Physiologischen Gesellschaft in Debrecen (6.–8. September 1951) gemacht. (Acta Physiol. Hungarica,13, 3. Suppl. 1952.)     

Evaluation and prognostic significance of human tissue kallikrein-related peptidase 10 (KLK10) in colorectal cancer

The prognosis of patients with colorectal cancer (CRC) is assessed through conventional clinicopathological parameters, which are not always accurate. Members of the human kallikrein-related peptidases gene family represent potential cancer biomarkers. The aim of this study was to investigate the expression of human tissue kallikrein-related peptidase 10 (KLK10) by immunohistochemistry in CRC, to correlate this expression with various histopathological and clinical variables, and to evaluate its significance as a predictor of disease outcome. KLK10 expression was evaluated by immunohistochemistry and a combined expression score was calculated for each case based on intensity and percentage of positivity. A statistically significant positive association was observed between KLK10 and tumor stage and liver metastases (p = 0.015 and p = 0.035, respectively). Paradoxically, a negative association was observed between KLK10 and tumor grade (p = 0.009). Kaplan-Meier survival curves and univariate analysis showed that both KLK10 expression and stage had statistically significant correlations with disease-free survival (DFS) (p = 0.030 and p < 0.001, respectively) and overall survival (p = 0.010 and p = 0.001, respectively). Cox multivariate analysis showed that both KLK10 expression and stage were independent predictors of unfavorable DFS (p = 0.057 and p = 0.001, respectively) and overall survival (p = 0.009 and p = 0.001, respectively). In conclusion, KLK10 immunostaining is an independent prognostic marker in patients with CRC.