Genetic tumor virulence markers identified in murine model.

2004 NOV 4 - (NewsRx.com & NewsRx.net) -- Genetic markers of tumor virulence have been identified in a murine model of breast cancer.

"FVB/N-Tg (MMTV-PyMT)[superscript]634Mul-transgenic mice develop multifocal mammary tumors with a high incidence of pulmonary metastasis," according to oncologists in the United States, who "demonstrated previously that mammary tumors derived from transgene-positive F1 progeny - in particular inbred strains - display altered latency, tumor growth rates, and metastatic rates when compared with the FVB/NJ homozygous parent."

"To identify genes with expression that might be critical in modifying the biological behavior of MMTV-PyMT tumors," T.H. Qiu and colleagues at the National Cancer Institute "performed a detailed comparative analysis of expression profiles from mammary tumors arising in the parental FVB/NJ background and F1 progeny from crosses with I/Lni, LP/J, MOLF/Ei, and NZB/B1NJ mice."

"Compared with normal mammary glands, gene expression profiles of tumors from all five strains exhibited upregulation of genes involved in cell growth (e.g., Cks1 and CDC25C) and downregulation of cell adhesion molecules, with many genes associated previously with human breast cancer such as STAT2, CD24 antigen, gelsolin, and lipocalin2," Qiu and collaborators said. "To identify genes with significant variation in expression between the five different genotypes, significance analysis of microarrays (SAM) and one-way ANOVA were used."

"Three definable groupings of tumors were identified: (a) tumors derived in the LP/J F1 and MOLF/Ei F1 strains in which tumor growth and dissemination are suppressed and latency prolonged; (b) the most aggressive tumors from the FVB/NJ parental strain and I/LnJ ...