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This review paper discusses the main molecular alterations of endometrial carcinoma, the most common cancer of the female genital tract. Two clinicopathological variants are recognized: the oestrogen-related (type I, endometrioid carcinoma) and the non-oestrogen-related (type II, non-endometrioid carcinoma). Whereas type I shows microsatellite instability and mutations in PTEN, PIK3CA, K-RAS and CTNNB1 (beta-catenin), type II exhibits TP53 mutations and chromosomal instability. Recent investigations regarding the role of non-coding RNA have provided important information regarding tumour progression. Understanding pathogenesis at the molecular level is essential for identifying biomarkers of potential use in targeted therapies. © 2012 Blackwell Publishing Limited.

This review article describes the main features of epithelial-to-mesenchymal transition (EMT) and its possible role in understanding myometrial invasion in endometrial carcinoma (EC), as well as the development of malignant mixed Mullerian tumor (MMMT). Moreover, the article discusses the possible role of somatic (SSC) and cancer stem cells (CSC) in EC. Different transcriptional repressors of E-cadherin have been identified in EMT, including Snail and Slug, ZEB1 and ZEB2, and E47 and Twist. The expression of some of these genes is increased at the myoinvasive front and correlates inversely with E-cadherin inmunoreactivity. Whereas the transient occurrence of the EMT phenomenon is important for myometrial invasion in conventional EC, MMMT shows permanent expression of EMT leading to repression of E-cadherin and increased expression of mesenchymal markers including proteins involved in skeletal muscle development. An SSC population, identified as a side population, assessed by the Hoechst dye exclusion test has been identified in human endometrium. CSCs have been defined in analogy to SSC as cancer cells that have the capacity to self-renew, which means undergoing divisions that allow the generation of more identical CSCs and give rise to the variety of more differentiated cells found in the malignancy. Although published data show that CD133(+) cells retain the characteristics of CSC, there is no conclusive evidence showing that CD133 is the universal marker for EC stem cells. Finally, a possible role for endometrial stem cells in the development of ovarian endometriosis and ovarian endometrioid carcinoma is commented. (C) 2013 Elsevier Inc. All rights reserved.

The molecular events implicated in the development of endometrial carcinosarcoma remain poorly understood. Using complementary DNA microarrays, we analyzed a group of 15 endometrial carcinosarcomas and compared their gene expression profiles with those obtained from a group of 23 endometrioid endometrial carcinomas. We demonstrated changes in the expression of genes modulating processes such as the epithelial to mesenchymal transition, muscle differentiation, the expression of cancer/testis antigens, and immune response in endometrial carcinosarcomas. The high mobility group AT-hook 2 gene is an embryonic nuclear factor that mediates epithelial to mesenchymal transition in various tumor models, and it was among the genes overexpressed in endometrial carcinosarcomas. High mobility group AT-hook 2 overexpression was confirmed in 54% of endometrial carcinosarcomas by quantitative real time-polymerase chain reaction and immunohistochemistry. Moreover, we found, a significant inverse correlation between the expression of high mobility group AT-hook 2 and let-7b, a member of the let-7 family of microRNAs that represses high mobility group AT-hook 2 expression. These changes were also associated with overexpression of Lin28B, a suppressor of microRNA biogenesis that is implicated in cancer progression and metastasis. Finally, high mobility group AT-hook 2 overexpression, which was detected in less than 3% of endometrioid endometrial carcinomas, was observed in many nonendometrioid carcinomas (46% of 28 samples). This pattern of expression, restricted to nonendometrioid carcinomas and endometrial carcinosarcomas, reflects a role for high mobility group AT-hook 2 in endometrial carcinogenesis that is associated with aggressive phenotypes and points to its potential use as a marker to distinguish between endometrioid and nonendometrioid tumors. (c) 2013 Elsevier Inc. All rights reserved.

Endometrial carcinoma (EC) is the most commonly diagnosed gynecologic malignancy in the western world. The majority of these cancers are curable, but a subset about 15-20% of endometrial tumors exhibits an aggressive phenotype. Based on clinic-pathological and molecular characteristics, EC has been classified into two groups: Type I estrogen-dependent adenocarcinomas, which have a good prognosis and an endometrioid histology, and Type II or non-estrogen-dependent EC associated with poor prognosis and non-endometrioid histology. EC develops as a result of a stepwise accumulation of alterations that seem to be specific of each histological type. However, more knowledge is needed to better understand the differences in the biology and the clinical outcome of EC. We would like to highlight the need to explore new potential biomarkers of EC as a tool for the detection and monitoring of aggressive endometria I tumors that, at the same time, will allow us to develop novel and more selective molecular targeted therapies against EC. (C) 2011 Published by Elsevier Ireland Ltd.

Endometrial carcinosarcomas (ECSs) undergo a true epithelial-mesenchymal transition (EMT). The molecular determinants of the EMT in vivo are unclear, although a role for some miRNAs, mainly involving the miR-200 family, was recently suggested from in vitro cellular models. We analysed the microRNA (miRNA) signatures associated to EMT in human carcinosarcomas, and determined their relationships with EMT markers and repressors of E-cadherin transcription. The expression of E-, P- and N-cadherin, cadherin-11, p120, vimentin, SPARC, fascin and caveolin-1 was studied in a group of 76 ECS by immunohistochemistry. In addition, real-time PCR was used to measure the differences in the expression of 384 miRNAs, E-cadherin, cadherin-11, SPARC, SNAIL, ZEB1, ZEB2, TWIST-1, TCF4, TGF beta 1 and TGF beta 2 between the epithelial and mesenchymal components of 23 ECSs. A loss of epithelial characteristics, including cadherin switching and the acquisition of a mesenchymal phenotype, was accompanied by changes in the profile of miRNA expression and the up-regulation of all the E-cadherin repressors analysed. A greater than five-fold difference in the expression of 14 miRNAs between both neoplastic components was seen. Members of the miR-200 family were down-regulated in the mesenchymal part of the ECS. In addition, miR-23b and miR-29c, which are involved in the inhibition of mesenchymal markers, and miR-203, which is involved in the inhibition of cell stemness, were also down-regulated. Up-regulated miRNAs included miR-155, miR-369-5p, miR-370, miR-450a and miR-542-5p. These data suggest that in human ECS, the interplay between transcriptional repressors of E-cadherin and miRNAs provides a link between EMT-activation and the maintenance of stemness. Copyright (C) 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Objetivo: Evaluar la rentabilidad de los estudios citológicos sucesivos del líquido pleural (LP) para diagnosticar malignidad y analizar la influencia que sobre aquella tienen el tiempo transcurrido entre los análisis, el tamaño del derrame y las características bioquímicas del LP. Métodos: Se revisaron retrospectivamente 1.427 pacientes con derrame pleural (DP), de los que 466 eran de causa maligna. En este último grupo se analizaron las citologías sucesivas, el tiempo transcurrido entre las mismas, las características bioquímicas del LP y el tamaño del DP. Resultados: La sensibilidad de una primera citología fue del 48,5%. Cuando un primer estudio citológico era negativo, un segundo era diagnóstico en el 28,6% de los casos, mientras que con dos citologías negativas un tercer estudio conseguía un 10,3% de positividades adicionales. El tipo de tumor condiciona la rentabilidad de la citología (66,5% en adenocarcinomas frente a 30,8% en mesoteliomas), pero no así el tiempo transcurrido entre los análisis citológicos sucesivos ni el tamaño del DP. De los parámetros bioquímicos del LP, un análisis multivariante mostró que sólo un cociente entre la glucosa del LP y del suero ≤ 0,75 se relacionaba con una mayor sensibilidad de la citología (74 vs. 47%, p < 0,001). Conclusión: Se aconseja repetir al menos una segunda citología en todo DP de etiología incierta, cuando una primera ha resultado negativa. Este segundo estudio se puede realizar de forma inmediata ya que el paso del tiempo no incrementa la rentabilidad. El porcentaje de positividades está influido por el tipo de tumor y por algunas características bioquímicas del LP, como el cociente entre la glucosa del LP y del suero. Objective: To assess the usefulness of repeat cytological examination of pleural fluid (PF) for diagnosing malignancy as well as the influence of time length between analyses, effusion's size and pleural fluid biochemistries on the diagnostic yield of cytology. Methods: Retrospective analysis of 1,427 patients with pleural effusion (PE), including 466 patients with malignant PE. In this latter group, the time length between cytological analysis, the size of the PE, and the biochemical characteristics of PF were recorded. Results: The first cytological analysis had a sensitivity of 48.5%. If this was negative, a second PF specimen was diagnostic in 28.6% of cases, whereas submission of a third PF specimen allowed 10.3% of additional diagnosis. The incidence of positive results depended on the primary tumor (e.g. 66.5% in adenocarcinomas, 30.8% in mesotheliomas), but neither on the time length between cytological analyses nor on the effusion's size. A multivariate analysis showed that a PF to serum glucose ratio ≤ 0.75 was associated with a higher diagnostic yield of cytology (74 vs. 47%, p < 0.001). Conclusion: At least a second PF specimen should be submitted immediately for cytologic analyis in all PE of unknown cause, when the first analysis is not contributory. To delay this second analysis does not increase diagnostic yield. The percentage of cases in which cytologic study of the PF established the diagnosis of malignant PE depends on the tumor type and on certain PF biochemical characteristics such as the PF to serum glucose ratio.

The INK4a/ARF locus encodes two distinct tumor suppressors, p16INK4a and p14ARF. Although the contribution of p16INK4a to human tumorigenesis through point mutation, deletion, and hypermethylation has been widely documented, little is known about specific p14ARF lesions and their consequences. Recent data indicate that p14ARF suffers inactivation by promoter hypermethylation in colorectal cancer cells. Because it is known that p14ARF prevents MDM2 nucleocytoplasmic shuttling and thus stabilizes p53 by attenuating MDM2-mediated degradation, we studied the relationship of p14ARF epigenetic silencing to the expression and localization of MDM2 and p53. Cancer cell lines with an unmethylated p14ARF promoter showed strong nuclear expression of MDM2, whereas in a colorectal cell line with p14ARF hypermethylation-associated inactivation, MDM2 protein was also seen in the cytosol. Treatment with the demethylating agent 5-aza-2'-deoxycytidine was able to reinternalize MDM2 to the nucleus, and p53 expression was restored. No apparent changes in retinoblastoma localization were observed. We also studied the profile of p14ARF promoter hypermethylation in an extensive collection of 559 human primary tumors of different cell types, observing that in colorectal, gastric, renal, esophageal, and endometrial neoplasms and gliomas, aberrant methylation of p14ARF was a relatively common epigenetic event. MDM2 expression patterns revealed that lack of p14ARF promoter hypermethylation was associated with tumors showing exclusive nuclear MDM2 staining, whereas MDM2 cytosolic staining was frequently observed in neoplasms with aberrant p14ARF methylation. Taken together, these data support that epigenetic silencing of p14ARF by promoter hypermethylation is a key mechanism in the disturbance of the MDM2 nuclear localization in human cancer.

Multiple endocrine neoplasia type 2B (MEN 2B) is a rare autosomal dominant process characterized by medullary thyroid carcinoma, pheochromocytoma, and mucosal neuromas. A point mutation at codon 918 of the RET protooncogene has been observed in approximately 90% of patients and families with MEN 2B. Mucosal neuromas are the most consistent and distinctive feature (100% of patients) of MEN 2B and are considered pathognomonic. We describe a 35-year-old woman with mucosal neuromas of the lower lip and tongue that appeared in early childhood. Examination did not reveal other abnormalities. After a follow-up of more than 22 years with periodic clinical, biochemical, and radiologic studies, no evidence of MEN 2B has been detected. Analysis of the RET protooncogene exons 10, 11, and 16 did not demonstrate point mutation in the MEN 2B region (M918T).

The suitability of formalin-fixed and paraffin-embedded tumor material was evaluated for molecular analysis of the RET proto-oncogene. We analyzed exons 10, 11, and 16 for point mutations in seven sporadic and six multiple endocrine neoplasia (MEN) 2A-associated pheochromocytomas by a nonradioactive single-strand conformation polymorphism assay followed by nonradioactive direct sequencing of PCR-amplified DNA using an automated DNA sequencer. All MEN 2A-associated pheochromocytomas contained a heterozygous missense germline mutation within cystine codons of the cysteine-rich extracellular domain encoded by exons 10 and 11. Mutations were located in codon 619 (TGC-->TCC; Cys-->Ser) in one, in codon 635 (TGC-->CGC; Cys--Arg) in three, and in codon 635 (TGC-->TAC; Cys-->Tyr) in two pheochromocytomas. No tumor-specific (somatic) mutations were detected in exons 10, 11, and 16 of the sporadic pheochromocytomas. These data support recent findings that germline point mutations that are clustered in distinct cysteine codons of the RET proto-oncogene are involved in the neoplastic phenotype of the MEN 2A syndrome. Our results demonstrate that both nonradioactive single-strand conformation polymorphism and direct sequencing are suitable methods to detect single base substitutions in DNA extracted from archival material.