Cancer-associated somatic DICER1 hotspot mutations cause defective miRNA processing and reverse-strand expression bias to predominantly mature 3p strands through loss of 5p strand cleavage.

Our group recently described recurrent somatic mutations of the miRNA processing gene DICER1 in non-epithelial ovarian cancer. Mutations appeared to be clustered around each of four critical metal-binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3' end of the 5p miRNA strand of a pre-mRNA hairpin. To investigate the effects of these cancer-associated 'hotspot' mutations, we engineered mouse DICER1-deficient ES cells to express wild-type and an allelic series of the mutant DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal-binding site mutations were compared to each other and to wild-type DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation-carrying cells were distinct from both wild-type and DICER1-deficient cells. Further, miRNA profiles showed that mutant DICER1 results in a dramatic loss in processing of mature 5p miRNA strands but were still able to create 3p strand miRNAs. Messenger RNA (mRNA) profile changes were consistent with the loss of 5p strand miRNAs and showed enriched expression for predicted targets of the lost 5p-derived miRNAs. We therefore conclude that cancer-associated somatic hotspot mutations of DICER1, affecting any one of four metal-binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p strand miRNA. We further propose that this resulting 3p strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations.

Sobrepoblación aanina y felina: tendencias y nuevas perspectivas / Canine and feliee overpopulation: trends and new perspectives

A través de una revisión sistemática de la literatura, publicada entre 1973 y 2009, se consultaron las siguientes bases de datos, a saber: ScienceDirect, Ebsco, Springerlink y Medline, para la búsqueda de la información. Como palabras clave se utilizaron: perros de libre ambulación, vínculo animal-humano, población de mascotas, sobrepoblación y control de población. Además se consultó el banco de publicaciones de la Sociedad Mundial para la Protección Animal (WSPA) y la Organización Internacional de Epizootias (OIE). El objetivo de esta revisión fue presentar una posición crítica sobre la problemática de la sobrepoblación de mascotas, su percepción cultural y la relación hombre-animal. Asimismo, los fracasos asociados con esta relación, estableciendo posibles soluciones sin desconocer nuestro marco cultural. Se obtuvo un total de dieciséis referencias, a las que se aplicó los criterios de inclusión y exclusión; los artículos que cumplieron estos criterios son los que constituyeron la unidad de análisis de esta revisión. A medida que aumente nuestro conocimiento acerca de la tenencia responsable de las mascotas, mejorarán nuestros vínculos afectivos con estas. Solo a través de la educación sanitaria se puede adquirir el conocimiento necesario para evitar fracasos con respecto a una tenencia adecuada, de allí la responsabilidad y el papel fundamental que ejerce el médico veterinario en la comunidad.

Through a systematic review of literature comprising publications between 1973 and 2009, the following databases were consulted: Science Direct, EBSCO, Springer Link and MEDLINE. Key words used included stray dogs, animal-human bond, pet population, overpopulation and population control. The databases of the World Society for the Protection of Animals (WSPA) and the International Organization of Epizootics (OIE) were also consulted. The objective of the present review was to present a critical position about the pet overpopulation problem, cultural perception and relationships between human and animals, and failures associated with this relationship with the purpose of establishing possible solutions to the problem taking into consideration cultural issues. A total of 16 references were found, which, we applied the inclusion and exclusion criteria. Articles that met these criteria are those that constitute the unit of analysis of this review. As the knowledge about responsible ownership of pets is increased, the bond with them is enhanced. Only through health education, it is possible to acquire the necessary knowledge needed to avoid failures with respect to proper keeping. In this respect the veterinarian plays a pivotal role with his community.

Germline mutations in CDH1 are infrequent in women with early-onset or familial lobular breast cancers.

BACKGROUND: Germline mutations in CDH1 are associated with hereditary diffuse gastric cancer; lobular breast cancer also occurs excessively in families with such condition. METHOD: To determine if CDH1 is a susceptibility gene for lobular breast cancer in women without a family history of diffuse gastric cancer, germline DNA was analysed for the presence of CDH1 mutations in 318 women with lobular breast cancer who were diagnosed before the age of 45 years or had a family history of breast cancer and were not known, or known not, to be carriers of germline mutations in BRCA1 or BRCA2. Cases were ascertained through breast cancer registries and high-risk cancer genetic clinics (Breast Cancer Family Registry, the kConFab and a consortium of breast cancer genetics clinics in the United States and Spain). Additionally, Multiplex Ligation-dependent Probe Amplification was performed for 134 cases to detect large deletions. RESULTS: No truncating mutations and no large deletions were detected. Six non-synonymous variants were found in seven families. Four (4/318 or 1.3%) are considered to be potentially pathogenic through in vitro and in silico analysis. CONCLUSION: Potentially pathogenic germline CDH1 mutations in women with early-onset or familial lobular breast cancer are at most infrequent.

Serous borderline ovarian tumors in long-term culture: phenotypic and genotypic distinction from invasive ovarian carcinomas.

Serous borderline ovarian tumors (SBOTs) are differentiated, slow growing, noninvasive, and have a better prognosis than their invasive counterparts, but recurrence and progression to invasive carcinomas are common, and unlike high-grade serous carcinomas, they tend to be nonresponsive to chemotherapy. However, due to a lack of culture systems and animal models, information about the properties of SBOT and their changes with neoplastic progression is extremely limited. Our objective was to establish a cell culture model for SBOTs and to characterize their phenotype and genotype. We compared cultures derived from two SBOTs, one of which was a short-term culture containing a BRAF mutation but few other cytogenetic changes while the other culture developed into a spontaneously immortalized permanent cell line and had numerical and structural chromosomal abnormalities but lacked RAS/BRAF mutations. Both cultures formed whorl-like epithelial colonies and resembled low-grade invasive carcinomas by their secretion of CA125 and oviduct-specific glycoprotein, production of matrix metalloproteinases, E-cadherin expression, and telomerase activity. Other characteristics associated with neoplastic transformation, including invasiveness, anchorage-independent growth, and tumorigenicity, were not observed. Importantly, cell motility was reduced in both lines, likely contributing to the lack of invasiveness. The results reveal a striking phenotypic similarity between the two cell lines, regardless of their cytogenetic diversity, which suggests that their characteristic phenotype is regulated to a large degree by epigenetic and environmental factors. In conclusion, we have established the first permanent SBOT cell line, which provides a new model to elucidate the undefined relationship of SBOTs to invasive ovarian carcinomas.

alphavbeta3 and vitronectin expression by normal ovarian surface epithelial cells: role in cell adhesion and cell proliferation.

The alphavbeta3 integrin and its ligand vitronectin are expressed by differentiated epithelial ovarian carcinomas and carcinoma cell lines in culture. Moreover, alphavbeta3/vitronectin interaction influences adhesion and migration of ovarian carcinoma cells in culture. For a better understanding of the behavior of these carcinomas, it appeared necessary to study the characteristics of their normal counterpart, the ovarian surface epithelium (OSE). The present study showed that normal cultured human OSE cells, like the carcinoma cells, have the ability to synthesize vitronectin. The vitronectin receptor, alphavbeta3 integrin, is also expressed by OSE cells and is localized in focal contacts close to paxillin, a focal contact-specific protein, and p125(FAK), a cytoskeletal and signaling molecule. This localization suggested an active participation of the integrin in the adhesion and/or proliferation of OSE cells. Indeed, the use of a blocking antibody demonstrated that alphav integrins promote OSE cell adhesion on vitronectin but not on fibronectin and that these integrins are required for maximal proliferative activity. The results suggest a role of the alphavbeta3/vitronectin system in normal OSE physiology and demonstrate that the expression of this system by well-differentiated ovarian carcinomas reflects the retention of normal cell properties.