Hematoxylin and eosin staining (<i>H&E</i>), Ki-67 and cyclin E immunostaining in normal kidney and diffuse anaplastic type nephroblastoma.

<p>Normal kidney (A, <i>H&E</i>) shows only scattered positive nuclei in tubules after using Ki-67 antibody (B) and no positive nuclei after using cyclin E antibody (C). Original magnification, ×40. Diffuse anaplastic nephroblastoma with anaplastic cells in the blastemal (D), stromal (G) and epithelial (J) component (<i>H&E</i>; original magnification, ×40). Immunostaining shows numerous blastemal positive cells (E,F), stromal (H,I) and epithelial cells (K,L) using Ki-67 (E,H,K) and cyclin E (F,I,L). Original magnification, ×40 for E, H, I, K, L, ×100 for F.</p

Clinical, histological and immunohistochemical characteristics of patients with nephroblastoma with or without metastasis.

*<p>significant difference between median age of patients with and without metastasis (<i>p</i> = 0.04)</p

Immunostaining in mixed type nephroblastoma with or without associated metastasis.

<p>Example of high Ki-67 (A) and high cyclin E <i>SI</i> (C,E,G) in the blastemal (A,C), in the stromal (E) or epithelial (G) component of a patient with a stage I mixed type nephroblastoma and pulmonary metastases (M+) in comparison with a patient with a stage III mixed type nephroblastoma without metastasis (M-) and low Ki-67 (B) and cyclin E (D,F,H) <i>SI</i> in corresponding components.</p

Hematoxylin and eosin staining, Ki-67 and Cyclin E immunostaining in nonanaplastic nephroblastoma.

<p>Examples of a blastemal type nephroblastoma (A, <i>H&E</i>) with a median <i>SI</i> of 25,5% for Ki-67 (B) and of 36% for cyclin E (C), of a blastemal component of a mixed type nephroblastoma (D, <i>H&E</i>) with a median <i>SI</i> of 33% for Ki-67 (E) and of 60% for cyclin E (F), of a stromal type nephroblastoma (G, <i>H&E</i>), with a median <i>SI</i> of 5% for Ki-67 (H) and of 30,5% for cyclin E (I), of an epithelial type nephroblastoma (J, <i>H&E</i>), with a <i>SI</i> of 30% for Ki-67 (K) and for cyclin E (L). Original magnification, ×40 for all panels except C, I, L (×100).</p

Ki-67 and cyclin E staining index (<i>SI</i>) in 54 postchemotherapy nephroblastoma. For each patient, age at surgery, sex, clinical features, tumor local stage and subtype, metastases and follow-up were specified. Median <i>SI</i> are in bold.

<p>blast = blastemal cells, strom = stromal cells, epith = epithelial cells, NI = noninterpretable</p

Box-Plot of the median Ki-67 and cyclin E <i>SI</i> in the different components of postchemotherapy nephroblastoma.

<p>Box-Plot of the median Ki-67 and cyclin E <i>SI</i> in the different components of postchemotherapy nephroblastoma.</p

Methylome sequencing for fibrolamellar hepatocellular carcinoma depicts distinctive features

<p>With the goal of studying epigenetic alterations in fibrolamellar hepatocellular carcinoma (FLC) and establish an associated DNA methylation signature, we analyzed <i>LINE-1</i> methylation in a cohort of FLC and performed next-generation sequencing of DNA methylation in a training set of pure-FLCs and non-cirrhotic hepatocellular carcinomas (nc-HCC). DNA methylation was correlated with gene expression. Furthermore, we established and validated an epigenetic signature differentiating pure-FLC from other HCCs. <i>LINE-1</i> methylation correlated with shorter recurrence-free survival and overall survival in resected pure-FLC patients. Unsupervised clustering using CG sites located in islands distinguished pure-FLC from nc-HCC. Major DNA methylation changes occurred outside promoters, mainly in gene bodies and intergenic regions located in the vicinity of liver developmental genes (i.e., <i>SMARCA4</i> and <i>RXRA</i>). Partially methylated domains were more prone to DNA methylation changes. Furthermore, we identified several putative tumor suppressor genes (e.g., <i>DLEU7</i>) and oncogenes (e.g., <i>DUSP4</i>). While ∼70% of identified gene promoters gaining methylation were marked by bivalent histone marks (H3K4me3/H3K27me3) in embryonic stem cells, ∼70% of those losing methylation were marked by H3K4me3. Finally, we established a pure FLC DNA methylation signature and validated it in an independent dataset. Our analysis reveals a distinct epigenetic signature of pure FLC as compared to nc-HCC, with DNA methylation changes occurring in the vicinity of liver developmental genes. These data suggest new options for targeting FLC based on cancer epigenome aberrations.</p