HER-2/neu gene amplification in stages I-IV breast cancer detected by fluorescent in situ hybridization.

Purpose: Approximately 25-30% of breast and ovarian carcinomas have amplification of the HER-2/neu oncogene. The aim of the present study was to focus on HER-2/neu gene amplification in different clinical stages of breast cancer in order to (1) determine if fluorescent in situ hybridization (FISH) can be used to detect HER-2/neu gene amplification in different clinical stages of breast cancer, (2) establish whether HER-2/neu gene amplification characterizes a subset of breast cancer in each of these stages, and (3) determine whether a trend for correlation of amplification with the clinical stage of the disease can be detected using the FISH technology.

Methods: A total of 40 specimens of formalin-fixed, paraffin-embedded breast cancer tissues were analyzed cytogenetically, in a blinded fashion, for HER-2/neu gene amplification using FISH and the Vysis LSI HER-2/neu Orange and CEP 17 Green DNA dual color probe.

A variant Klinefelter syndrome patient with an XXY/XX/XY karyotype studied by GTG-banding and fluorescence in situ hybridization.

Klinefelter syndrome is the first human sex chromosomal abnormality to be reported. The majority of Klinefelter syndrome patients have the XXY karyotype. Approximately 15% of Klinefelter patients, however, are mosaics with variable phenotypes.

Fluorescence in situ hybridization analysis of single-cell trisomies for determination of clonality.

Conflicting data currently exist pertaining to the significance of single-cell trisomies found in a 20-cell cytogenetic analysis of hematologic malignancies. In order to determine the clonality of the numerical abnormalities found in these cases, we performed a retrospective study on a cohort of patients previously analyzed by GTG-banding at Rhode Island Hospital, from July 1, 1990 to November 30, 1996. Fluorescence in situ hybridization (FISH) was performed using chromosome enumeration probes on previously fixed bone marrow and, in some cases, peripheral blood slides from patients identified to have single-cell trisomies of selected chromosomes in 20-cell routine GTG-banded analyses.

Sequential flow cytometry and fluorescence in situ hybridization for the study of formalin-fixed, paraffin-embedded breast cancer cells.

Both flow cytometry and fluorescence in situ hybridization (FISH) are useful techniques in the analysis of cancer tissues. When the two are used in the study of the same specimens, they are usually performed in parallel, separately. This is problematic where there is a scarcity of material, making completion of both studies impossible.

A practical cytogenetic protocol for in vitro cytotoxicity and genotoxicity testing.

In vitro cytogenetics has been established as a valid method for evaluating the genotoxic potential of chemical agents. Armstrong et al have described a simple, quantitative approach to in vitro cytotoxicity and genotoxicity testing by using Chinese hamster ovary (CHO) cells. This approach can also be sensitive and repeatable in an inter-laboratory setting, a prerequisite for routine testing of compounds suspected of having genotoxic properties.