Evaluation of spectral karyotyping (SKY) in biodosimetry for the triage situation following gamma irradiation.

Purpose: Biological dosimetry in an acute triage situation of radiation exposure is traditionally performed by scoring unstable dicentric chromosomal aberrations after conventional Giemsa staining, and more recently also by detection of chromosomal translocations after chromosome painting by fluorescence in situ hybridization (FISH). By spectral karyotyping (SKY) each chromosome can be painted in an individual colour, permitting the scanning for structural aberrations throughout the genome in each individual metaphase. Here we have evaluated the performance of SKY analysis in a simulated triage situation after gamma irradiation.

Rad51-related changes in global gene expression.

High expression of Rad51, the catalytic component in homologous recombination, has been reported to contribute to genomic instability. To elucidate biological processes related to Rad51, we performed global gene expression analysis on human fibrosarcoma cells induced to express variable Rad51 levels. The results indicate that Rad51 overexpression mediates late rather than early transcriptional responses.

Culture and expansion of the human embryonic stem cell line HS181, evaluated in a double-color system.

An approach of using RFP-transfected human foreskin fibroblasts (hFS-RFP) to support the growth of GFP expressing human embryonic stem cells (hES; HS181-GFP) is reported. The two-color system was applied to detect interactions between hFS and human embryonic stem cells (hES). After overnight culture, the hES cell colonies showed a behavior of "pushing away" the underlying feeder cells.

Consistent downregulation of human lactoferrin gene, in the common eliminated region 1 on 3p21.3, following tumor growth in severe combined immunodeficient (SCID) mice.

Lactoferrin (LF) is one of 19 active genes in the common eliminated region 1 at 3p21.3 identified by us. LF was transfected into mouse fibrosarcoma A9.

Fluorescence in situ hybridization (FISH) in the molecular cytogenetics of cancer.

In this review, we discuss the developments of fluorescence in situ hybridization (FISH) and place them in the context of their applications in cancer research. These methods are not only very useful for the causal analysis of the development and spread of certain tumors, they are also efficient tools for tumor diagnosis. Although a review of all of the literature in this field is not possible here, many of the major contributions are summarized along with recent work from our laboratory.

Loss of the p21(Cip1/Waf1) cyclin kinase inhibitor results in propagation of horizontally transferred DNA.

We have shown previously that phagocytosis of cells dying by apoptosis results in transfer of whole or fragments of chromosomes into the nucleus of the recipient cell. Although DNA transfer was detected in normal cells, stable propagation of the transferred DNA was only observed in cells deficient in p53. Here we show that mouse embryonic fibroblast cells lacking the p21 (Cip1/Waf1) cyclin-kinase inhibitor are able to propagate DNA engulfed by phagocytosis of apoptotic bodies.