Quadruplex-forming guanine-rich nucleic acid sequences are useful in compositions and methods for inhibiting cellular growth and proliferation and inducing cell death. Compositions for treating a patient are provided, including (i) a safe and effective amount of a sequence having at least 80% nucleic acid identity with a sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12 and combinations thereof, and (ii) a carrier, wherein the isolated oligonucleotide forms at least one quadruplex.