Numerous tumor suppressor genes — including PTEN and p53 — are down regulated in sporadic breast cancer but the molecular basis of cancer development remains incompletely understood. In the Early Edition of Proceedings of the National Academy of Sciences of the USA, Masaaki Hamaguchi and colleagues from Cold Spring Harbor Laboratory, New York, show that DBC2 (deleted in breast cancer) is a new candidate for a tumor suppressor gene involved in breast cancer (PNAS, DOI/10.1073/212516099, October 9, 2002).

Hamaguchi et al. analyzed breast cancer biopsies by representational difference analysis (RDA). They observed that an RDA probe detecting homozygous deletion mapped to human chromosome 8p21, and that DBC2 is the best candidate tumor suppressor gene from this region. DBC2 expression in breast cancer cells lacking DBC2 caused growth inhibition. In addition, they observed that DBC2 derived from breast tumor specimens contain somatic missense mutations.

"All these data...