Chemoprevention

Chemopreventive property of a soybean peptide (lunasin) that binds to deacetylated histones and inhibits acetylation. Galvez, A. F. et al. Cancer Res. 61, 7473–7478 (2001) [PubMed]

A protein from the humble soybean has been found to lower the rate of skin cancer in mice. The soy protein lunasin, discovered 2 years ago, is a chromatin-binding protein that inhibits mitosis in cell culture. Galvez et al. report that lunasin-treated cells are less likely to undergo transformation, and that mice treated with lunasin had a 70% lower incidence of skin cancer than controls after exposure to chemical carcinogens. This might explain the numerous epidemiological associations between consumption of soy products and low cancer incidence.

Metastasis

A phosphatase associated with metastasis of colorectal cancer. Saha, S. et al. Science 11 October 2001; [epub ahead of print] [PubMed]

Colorectal cancer is one of the best characterized cancers at the molecular level, but most of the genes involved in its development are inactivated or deleted, making it difficult to target them with drugs. Using serial analysis of gene expression, Saha et al. have found a protein tyrosine phosphatase-encoding gene — PRL3 — that is overexpressed in colorectal tumours that metastasize to liver. The gene is located in a region of chromosome 8q that is amplified in some metastatic colorectal cancers.

Viral carcinogenesis

SV40 replication in human mesothelial cells induces HGF/Met receptor activation: a model for viral-related carcinogenesis of human malignant mesothelioma. Cacciotti, P. et al. Proc. Natl Acad. Sci. USA 98, 12032–12037 (2001) [PubMed]

Simian virus 40 (SV40) is present in 60% of mesotheliomas, but is it involved in the development of this cancer? Cacciotti and colleagues find that infection with SV40, or transfection with the gene that encodes SV40 large T antigen, sets up an autocrine loop in which the infected cells produce hepatocyte growth factor (scatter factor) and activate its receptor — the c-MET oncoprotein.

Drug discovery

Use of isogenic human cancer cells for high-throughput screening and drug discovery. Torrance, C. J. et al. Nature Biotech. 19, 940–945 (2001) [Contents page]

A new strategy for drug screening involves the use of two human cancer cell lines that are genetically identical except that one is deleted for a key oncogene — KRAS. By labelling each cell line with a different variant of green fluorescent protein and co-culturing them, the authors monitored growth rate of the two cell lines in response to test compounds.