The present invention relates to nucleic acid molecules that simultaneously inhibit the expression of AR gene and mTOR gene, wherein the double-stranded siRNA and shRNA of the present invention were designed to simultaneously inhibit the expression of the AR gene and the mTOR gene which are associated with cancer. The double-stranded siRNA and shRNA of the present invention promote cancer cell death and synergistically enhance cancer cell death in combination with an anticancer agent, so that various types of cancer can be effectively prevented and treated.