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CDC25A phosphatase, an essential component of the cell cycle machinery, is also a key player in integrating the specific signals of checkpoint control in response to DNA damage. There are several lines of evidence that indicate a role for CDC25A in cancer development, consistent with the fact that its overexpression is detected in human cancers. In particular we previously reported that CDC25A is overexpressed also in early breast carcinoma. Recent data suggest that oncogene activation during early stages of tumor development causes DNA replication stress resulting in the induction of DNA damage response (DDR) and that the selection of cells defecting in their DDR could lead to malignant progression. To address how CDC25A overexpression contributes to breast cancer development we established a cell model in which CDC25A was constitutively overexpressed in hTERT-immortalized primary human mammary epithelial cells. At the earliest passages following CDC25A transduction we observed DDR signs associated with unscheduled DNA replication origins. In the latest passages DDR was significantly impaired and, even after ionizing radiation exposition, cells failed to induce G1 and G2 checkpoints; moreover DNA replication stress conditions, such as aphidicolin treatment, highlighted increased fragile site breakages and destabilized chromosomes just in these latest passages cells. Our data suggest that CDC25A overexpression, pushing the cell through the cell cycle transitions, induces DDR alterations that might enhance genomic instability., (Copyright 2008 Wiley-Liss, Inc.)

Ocular adnexal MALT lymphoma (OAML) is linked to Chlamydophila psittaci (Cp) infection. Viability and infectivity of Cp, demonstrated by growth in culture, has not been yet investigated in these patients. We conducted a single-center prospective case-control study to assess the prevalence, viability and infectivity of Cp in 20 OAML patients and 42 blood donors registered in a 6-month period. The presence of Cp in conjunctival swabs and peripheral blood mononuclear cells (PBMC) of patients and donors was assessed by TETR-PCR and in vitro cultures. From an epidemiological point of view, OAML patients often resided in rural areas, and reported a history of chronic conjunctivitis and prolonged contact with household animals (85% vs. 38% of donors; p = 0.00001). Cp was detected in lymphoma tissue in 15 (75%) patients. Cp DNA was detected in conjunctival swabs and/or PBMC from 10 (50%) patients and in PBMC from 1 (2%) donor (p = 0.01). Viability and infectivity of Cp, demonstrated by growth in culture, were confirmed in conjunctival swabs and/or PBMC from 5 (25%) patients, but not in donors (p = 0.002). This prospective study demonstrates, for the first time, that Cp present in the conjunctiva and PBMC of OAML patients is capable to grow and be isolated in cell cultures. Cp infection is common in OAML patients and exceptional in blood donors. Epidemiological data of OAML patients (prolonged contact with household animals and chronic conjunctivitis) are consistent with Cp exposure risk.

Renal-cell carcinoma (RCC) constitutes a heterogeneous group of tumors with specific chromosome aberrations. Recently, a new small group of RCC, occurring in children and young adults, has been described as characterized by t(6;11)(p21;q12). It has been shown that this translocation results in the fusion of the 5' portion of the ALPHA gene (11q12) with the transcription factor gene TFEB (6p21). Herewith, we report the first complete cytogenetic and molecular characterization of a t(6;11)-positive RCC of an adult patient, a 54-year-old woman. The tumor was histologically defined as RCC with peculiar features and it was negative for epithelial markers and positive for melanocytic markers. Chromosome QFQ banding analysis of short-term cultured cells from the RCC showed t(6;11)(p21;q12) as the sole cytogenetic abnormality. The translocation was confirmed by FISH analysis. RT-PCR analysis, performed on total RNA isolated from both neoplastic and normal tissue samples, revealed an ALPHA-TFEB chimeric transcript in the tumor sample; sequencing of the RT-PCR product defined a novel TFEB gene breakpoint cluster region, broader than the one reported thus far. Western blot analysis showed a band at the expected size of wild-type TFEB in the neoplastic tissue compared to the normal sample, supporting that the fusion gene does not encode for a chimeric protein but it causes an upregulation of the wild-type TFEB. Our data contribute to define better this rare RCC type, which is typical not only of childhood but can also be found in adulthood., ((c) 2007 Wiley-Liss, Inc.)