Elevated TRF2 in advanced breast cancers with short telomeres.

Telomere repeat binding factor 2 (TRF2) binds directly to telomeres and preserves the structural integrity of chromosome ends. In vitro models suggest that expression of TRF2 protein increases during mammary cancer progression. However, a recent study has reported that TRF2 mRNA levels tend to be lower in clinical specimens of malignant breast tissue.

Translocations and amplifications of chromosome 12 in liposarcoma demonstrated by the LSI CHOP breakapart rearrangement probe.

Context: Liposarcomas display a number of molecular abnormalities involving chromosome 12. Myxoid and round cell liposarcomas are characterized by t(12;16)(q13; p11) or t(12;22)(q13;q12) translocations. Amplifications occur within the 12q13-15 region of atypical lipomatous tumors and well-differentiated liposarcomas but not lipomas.

Utility of EGFR and PTEN numerical aberrations in the evaluation of diffusely infiltrating astrocytomas. Laboratory investigation.

Object: Diffusely infiltrating astrocytomas are the most common primary brain tumors. As a group, they demonstrate an inherent tendency toward malignant progression. Histological grading using the guidelines of the World Health Organization (WHO) remains the gold standard for predicting the biological behavior of these tumors.

Desmoplastic small round cell tumor: using FISH as an ancillary technique to support cytologic diagnosis in an unusual case.

Desmoplastic small round cell tumor is a rare and aggressive neoplasm that predominantly affects young males. In almost all cases, a reciprocal translocation is present resulting in the fusion of the Ewing sarcoma gene with the Wilms' tumor gene. Here we describe an unusual case occurring in a 59-year-old male, in which fluorescence in situ hybridization (FISH) was used in conjunction with immunohistochemical studies to confirm the diagnosis.

Telomerase protects cancer-prone human cells from chromosomal instability and spontaneous immortalization.

Studies were conducted to directly test whether the introduction of telomerase protects cancer-prone human mammary epithelial cells from chromosomal instability and spontaneous immortalization. Using a model for Li Fraumeni Syndrome (LFS), infection of human telomerase resulted in maintenance of telomere lengths, extension of in vitro lifespan, and prevention of spontaneous immortalization. In stark contrast to the spontaneously immortalized LFS cells, cells expressing ectopic telomerase displayed a remarkably stable karyotype and even after >150 population doublings, did not express endogenous telomerase.