In the burgeoning field of epigenetics, there are several methods available to determine the methylation status of DNA samples. However, choosing the method that is best suited to answering a particular biological question still proves to be a difficult task. This review aims to provide biologists, particularly those new to the field of epigenetics, with a simple algorithm to help guide them in the selection of the most appropriate assay to meet their research needs. First of all, we have separated all methods into two categories: those that are used for: (1) the discovery of unknown epigenetic changes; and (2) the assessment of DNA methylation within particular regulatory regions/genes of interest. The techniques are then scrutinized and ranked according to their robustness, high throughput capabilities and cost. This review includes the majority of methods available to date, but with a particular focus on commercially available kits or other simple and straightforward solutions that have proven to be useful.

Summary: Context: TERT promoter mutations have been associated with adverse prognosis in papillary thyroid carcinomas (PTCs).Objective: We investigated the association between TERT promoter mutations and survival from PTC.Design: Retrospective observational cohort study.Patients: Eighty consecutive patients with PTC who underwent surgery between 1990 and 2003.Measurements: TERT promoter was genotyped in DNA from 80 archival PTCs by Sanger sequencing. Median follow‐up was 106 months (range 1–270). Outcomes analysis was stratified according to disease and overall survival status. For each parameter, relative risk (RR) adjusted for age at first surgery and gender was estimated. Both univariate and multivariate analyses were performed using logistic regression, Kaplan–Meier survival analysis and Cox regression models.Results: PTCs from 11 patients (14%) contained either C228T or C250T TERT promoter mutation. TERT mutations were significantly associated with adverse prognostic features such as older age (P = 0·002), male gender (P = 0·01) and Stage IV disease (P = 0·03). Four patients died from PTC during follow‐up: 3 patients with TERT mutations (27%) and one without (1·5%). Disease‐related mortality rate with or without TERT mutations was 33·7 vs 1·6 per 1000 patient‐years respectively, that is 10 (95% CI = 1·0–104·1, P = 0·05) fold higher, after adjustment for age at first surgery and gender. The combination of TERT promoter mutation and BRAF^V600E significantly increased disease‐related death risk (P = 0·002). TERT mutations increased expression of a reporter gene in thyroid cells containing BRAF^V600E.Conclusions: TERT promoter mutations are a major indicator of death due to PTCs. Conversely, absence of TERT mutations portends better survival.

Identification of BRAF^V600E in thyroid neoplasia may be useful because it is specific for malignancy, connotes a worse prognosis, and is the target of novel therapies currently under investigation. Sanger sequencing is the ‘gold standard’ for mutation detection but is subject to sampling error and requires resources beyond many diagnostic pathology laboratories. In this study, we compared immunohistochemistry (IHC) using a BRAF^V600E mutation-specific MAB to Sanger sequencing on DNA from formalin-fixed paraffin-embedded tissue, in a well-characterized cohort of 101 papillary thyroid carcinoma (PTC) patients. For all cases, an IHC result was available; however, five cases failed Sanger sequencing. Of the 96 cases with molecular data, 68 (71%) were BRAF^V600E positive by IHC and 59 (61%) were BRAF^V600E positive by sequencing. Eleven cases were discordant. One case was negative by IHC and initially positive by sequencing. Repeat sequencing of that sample and sequencing of a macrodissected sample were negative for BRAF^V600E. Of ten cases positive by IHC but negative by sequencing on whole sections, repeat sequencing on macrodissected tissue confirmed the IHC result in seven cases (suggesting that these were false negatives of sequencing on whole sections). In three cases, repeat sequencing on recut tissue remained negative (including using massive parallel sequencing), but these cases demonstrated relatively low neoplastic cellularity. We conclude that IHC for BRAF^V600E is more sensitive and specific than Sanger sequencing in the routine diagnostic setting and may represent the new gold standard for detection of BRAF^V600E mutation in PTC.

The majority of metastatic breast cancers cannot be cured and present a major public health problem worldwide. Approximately 70% of breast cancers express the estrogen receptor, and endocrine-based therapies have significantly improved patient outcomes. However, the development of endocrine resistance is extremely common. Understanding the molecular pathways that regulate the hormone sensitivity of breast cancer cells is important to improving the efficacy of endocrine therapy. It is becoming clearer that the PI3K–AKT–forkhead box O (FOXO) signaling axis is a key player in the hormone-independent growth of many breast cancers. Constitutive PI3K–AKT pathway activation, a driver of breast cancer growth, causes down-regulation of FOXO tumor suppressor functions. This review will summarize what is currently known about the role of FOXOs in endocrine-resistance mechanisms. It will also suggest potential therapeutic strategies for the restoration of normal FOXO transcriptional activity.