Both Breast and prostate cancers are dependent on the actions of sex hormones mediated through their nuclear receptors in onset and development of the cancers. Nuclear estrogen and androgen receptors(ER and AR)are DNA-binding transcription factors and regulate expressions of the target mRNA genes by modulating chromatin structure and function. In this short review, the function of nuclear sex hormone receptors in sex hormone-depend cancers are overviewed in the chromatin reorganization for target gene regulations. Moreover, the role of enhancer RNA(eRNA), one of the non-coding RNAs, in chromatin reconfiguration is discussed for enhancer function in tumor development.