The invention provides oligonucleotides complementary to a non-coding chimeric mitochondrial RNA as well as compositions and kits comprising the same, and their use in treating and preventing metastasis or relapse of a cancer in an individual previously treated for cancer with a therapy. The invention also provides oligonucleotides complementary to a non-coding chimeric mitochondrial RNA as well as compositions and kits comprising the same, and their use in treating a refractory cancer (e.g., a refractory HPV-associated cancer).