The invention relates to antisense oligonucleotides, in particular to antisense oligonucleotides to receptor genes, and the use of such oligonucleotides to regulate reproductive function and as chemopreventive or as a chemotherapeutic for various cancers, especially ovarian cancers. The invention also provides a method for preventing estrogen synthesis, a function of developing ovarian follicles, a therapeutic consideration for the prevention and treatment of some cancers of the breast, endometrium, ovary and cervix and of some endometriosis. The invention also relates to pharmaceutical compositions containing antisense oligonucleotides (ODNs, having 8 to 60 nucleotides) that act by binding to intracellular molecular targets. Optionally, for efficient delivery to a target DNA, RNA or protein, the ODNs may be covalently linked to a carrier moiety, which facilitates delivery of the ODN to the cytosol.