DIFFERENTIAL EXPRESSION OF ESTROGEN-REGULATED GENES IN BREAST-CANCER

Pathological endpoints such as tumour size, lymph node status and vasc ular invasion remain the most useful guides in selecting treatment str ategies for breast cancer. There is a need, however, to further invest igate the molecular mechanisms that determine the properties of an ind ividual tumour e.g., hormone responsiveness and probability of metasta sis. While numerous prognostic factors have now been identified few ha ve contributed to defining clinical response to therapy. Oestrogen-reg ulated genes are likely to be important since they not only define a f unctional oestrogen receptor, but alterations in their expression migh t provide insights into the mechanisms involved in tumour progression and loss of endocrine sensitivity. Recently an oestrogen responsive ge ne, pLIV1, has been isolated and shown to be expressed in ER+ disease where it appears to predict nodal involvement. The present paper descr ibes aspects of its regulation and discusses the potential role of thi s and other genes in the development of endocrine resistance.