Patent ID: 7635561

Claim:
A method of diagnosing breast cancer, comprising the steps of: (1) obtaining a sample of breast cancer cells; and (2) determining the DNA methylation pattern of the ER-α gene promoter in the cells, wherein: (i) the presence of DNA methylation in the A, B, C and E regions of the ER-α gene promoter in the cells indicates that the cells are estrogen receptor-negative; and (ii) no DNA methylation in the ER-α gene promoter of the cells, or the presence of DNA methylation only in the D region of the ER-α gene promoter in the cells, indicates that the cells are estrogen receptor-positive (iii) step 2 further comprising detecting a multimolecular complex bound to the ER-α gene promoter, and wherein: (a) the presence of DNA methylation in the A, B, C and E regions of the ER-α gene promoter in the cells, and the presence of pRb2/p130-E2F4/5-HDAC1-DNMT1-SUV39H1 complex bound to the ER-α gene promoter in the cells, indicates that the cells are estrogen receptor-negative; and (b) no DNA methylation in the ER-α gene promoter of the cells or the presence of DNA methylation only in the D region of the ER-α gene promoter in the cells, and the presence of pRb2/p130-E2F4/5-HDAC1-SUV39H1-P300 complex bound to the ER-α gene promoter in the cells, indicates that the cells are estrogen receptor-positive.