Ashish Chandra

Regulation of E-cadherin Expression by VHL and Hypoxia-Inducible Factor

Mutations in von Hippel-Lindau tumor suppressor gene (VHL) underlie the VHL hereditary cancer syndrome and also occur in most sporadic clear cell renal cell cancers (CCRCC). Currently, the mechanism(s) by which VHL loss of function promotes tumor development in the kidney are not fully elucidated. Here, we show that VHL inactivation in precancerous lesions in kidneys from patients with VHL disease correlates with marked down-regulation of the intercellular adhesion molecule E-cadherin. Moreover, in VHL-defective cell lines (RCC4 and RCC10) derived from sporadic CCRCC, reexpression of VHL was found to restore E-cadherin expression. The product of the VHL gene has multiple reported functions, the best characterized of which is its role as the recognition component of an ubiquitin E3 ligase complex responsible for mediating oxygen-dependent destruction of hypoxia-inducible factor-alpha (HIF-alpha) subunits. We show that HIF activation is necessary and sufficient to suppress E-cadherin in renal cancer cells. Given the fundamental role of E-cadherin in controlling epithelial behavior, our findings give insight into how VHL inactivation/HIF activation may lead to kidney cancer and also indicate a mechanism by which reduced oxygenation could alter E-cadherin expression in other cancers and influence normal homeostasis in other epithelia.

Aberrant succination of proteins in fumarate hydratase-deficient mice and HLRCC patients is a robust biomarker of mutation status

Germline mutations in the FH gene encoding the Krebs cycle enzyme fumarate hydratase predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. FH‐deficient cells and tissues accumulate high levels of fumarate, which may act as an oncometabolite and contribute to tumourigenesis. A recently proposed role for fumarate in the covalent modification of cysteine residues to S‐(2‐succinyl) cysteine (2SC) (termed protein succination) prompted us to assess 2SC levels in our existing models of HLRCC. Herein, using a previously characterized antibody against 2SC, we show that genetic ablation of FH causes high levels of protein succination. We next hypothesized that immunohistochemistry for 2SC would serve as a metabolic biomarker for the in situ detection of FH‐deficient tissues. Robust detection of 2SC was observed in Fh1 (murine FH)‐deficient renal cysts and in a retrospective series of HLRCC tumours (n = 16) with established FH mutations. Importantly, 2SC was undetectable in normal tissues (n = 200) and tumour types not associated with HLRCC (n = 1342). In a prospective evaluation of cases referred for genetic testing for HLRCC, the presence of 2SC‐modified proteins (2SCP) correctly predicted genetic alterations in FH in every case. In two series of unselected type II papillary renal cancer (PRCC), prospectively analysed by 2SCP staining followed by genetic analysis, the biomarker accurately identified previously unsuspected FH mutations (2/33 and 1/36). The investigation of whether metabolites in other tumour types produce protein modification signature(s) that can be assayed using similar strategies will be of interest in future studies of cancer. Copyright

The Interobserver Reproducibility of Thyroid Fine-Needle Aspiration Using the UK Royal College of Pathologists’ Classification System

The overall interobserver reproducibility of thyroid fine-needle aspiration (FNA) has not been comprehensively assessed. A blinded 6-rater interobserver reproducibility study was conducted of 200 thyroid FNA cases using the UK System, which is similar to The Bethesda System for Reporting Thyroid Cytology: Thy1, nondiagnostic; Thy2, nonneoplastic; Thy3a, atypia, probably benign; Thy3f, follicular lesion; Thy4, suspicious of malignancy; and Thy5, malignant. There was good interobserver agreement for the Thy1 (κ = 0.69) and Thy5 (κ = 0.61), moderate agreement for Thy2 (κ = 0.55) and Thy3f (κ = 0.51), and poor agreement for Thy3a (κ = 0.11) and Thy4 (κ = 0.17) categories. Combining categories implying surgical management (Thy3f, Thy4, and Thy5) achieved good agreement (κ = 0.72), as did combining categories implying medical management (Thy1, Thy2, and Thy3a; κ = 0.72). The UK thyroid FNA terminology is a reproducible and clinically relevant system for thyroid FNA reporting. This study demonstrates that international efforts to harmonize and refine thyroid cytology classification systems can improve consistency in the clinical management of thyroid nodules.

BSCC Code of Practice--fine needle aspiration cytology.

The British Society for Clinical Cytology Code of Practice on fine needle aspiration cytology complements that on exfoliative cytopathology, which was published in the last issue (Cytopathology 2009;20:211–23). Both have been prepared with wide consultation within and outside the BSCC and have been endorsed by the Royal College of Pathologists. A separate code of practice for gynaecological cytopathology is in preparation. Fine needle aspiration (FNA) cytology is an accepted first line investigation for mass lesions, which may be targeted by palpation or a variety of imaging methods. Although FNA cytology has been shown to be a cost‐effective, reliable technique its accurate interpretation depends on obtaining adequately cellular samples prepared to a high standard. Its accuracy and cost‐effectiveness can be seriously compromised by inadequate samples. Although cytopathologists, radiologists, nurses or clinicians may take FNAs, they must be adequately trained, experienced and subject to regular audit. The best results are obtained when a pathologist or an experienced and trained biomedical scientist (cytotechnologist) provides immediate on‐site assessment of sample adequacy whether or not the FNA requires image‐guidance. This COP provides evidence‐based recommendations for setting up FNA services, managing the patients, taking the samples, preparing the slides, collecting material for ancillary tests, providing rapid on‐site assessment, classifying the diagnosis and providing a final report. Costs, cost‐effectiveness and rare complications are taken into account as well as the time and resources required for quality control, audit and correlation of cytology with histology and outcome. Laboratories are expected to have an effective quality management system conforming to the requirements of a recognised accreditation scheme such as Clinical Pathology Accreditation (UK) Ltd.

Recurrent chromosomal gains and heterogeneous driver mutations characterise papillary renal cancer evolution

Papillary renal cell carcinoma (pRCC) is an important subtype of kidney cancer with a problematic pathological classification and highly variable clinical behaviour. Here we sequence the genomes or exomes of 31 pRCCs, and in four tumours, multi-region sequencing is undertaken. We identify BAP1, SETD2, ARID2 and Nrf2 pathway genes (KEAP1, NHE2L2 and CUL3) as probable drivers, together with at least eight other possible drivers. However, only ~10% of tumours harbour detectable pathogenic changes in any one driver gene, and where present, the mutations are often predicted to be present within cancer sub-clones. We specifically detect parallel evolution of multiple SETD2 mutations within different sub-regions of the same tumour. By contrast, large copy number gains of chromosomes 7, 12, 16 and 17 are usually early, monoclonal changes in pRCC evolution. The predominance of large copy number variants as the major drivers for pRCC highlights an unusual mode of tumorigenesis that may challenge precision medicine approaches.

Endoscopic ultrasound-guided fine needle aspiration cytology of pancreatic neuroendocrine tumours: cytomorphological and immunocytochemical evaluation

Objectives:  Endoscopic ultrasound (EUS)‐guided fine needle aspiration (FNA) is increasingly used in preoperative localization and diagnosis of pancreatic neoplasms including neuroendocrine tumours (NETs). The objective of the present study was to identify the cytological features of pancreatic NETs obtained by EUS‐FNA.

Diagnostic terminology for reporting thyroid fine needle aspiration cytology: European Federation of Cytology Societies thyroid working party symposium, Lisbon 2009

G. Kocjan, B. Cochand‐Priollet, P. P. de Agustin, C. Bourgain, A. Chandra, Y. Daneshbod, A. Deery, J. Duskova, C. Ersoz, G. Fadda, A. Fassina, P. Firat, B. Jimenez‐Ayala, P. Karakitsos, O. Koperek, N. Matesa, D. Poller, L. Thienpont, A. Ryska, U. Schenck, T. Sauer, F. Schmitt, E. Tani, T. Toivonen, M. Tötsch, G. Troncone, L. Vass and P. Vielh
Diagnostic terminology for reporting thyroid fine needle aspiration cytology: European Federation of Cytology Societies thyroid working party symposium, Lisbon 2009

Indications, results and safety profile of transperineal sector biopsies (TPSB) of the prostate: a single centre experience of 634 cases

To describe a protocol for transperineal sector biopsies (TPSB) of the prostate and present the clinical experience of this technique in a UK population.

Hexylaminolaevulinate fluorescence cystoscopy in patients previously treated with intravesical bacille Calmette‐Guérin

Study Type – Diagnosis (case series) Level of Evidence 4

Hexylaminolaevulinate ‘blue light’ fluorescence cystoscopy in the investigation of clinically unconfirmed positive urine cytology

To investigate the value of photodynamic diagnosis (PDD) using hexylaminolaevulinate (Hexvix®, PhotoCure, Oslo, Norway) in the investigation of patients with positive urine cytology who have no evidence of disease after standard initial investigations.