Recent advances in
chemotherapy treatments are increasingly targeted
therapies, with the drug conjugated to an antibody able to deliver it directly to the
tumor. As high-affinity chemical
ligands that are much smaller in size, aptamers are ideal for this type of drug targeting. Aptamer-highly toxic drug conjugates (ApTDCs) based on the E3 aptamer, selected on
prostate cancer cells, target and inhibit prostate
tumor growth in vivo. Here, we observe that E3 also broadly targets numerous other
cancer types, apparently representing a universal aptamer for
cancer targeting. Accordingly, ApTDCs formed by conjugation of E3 to the drugs
monomethyl auristatin E (MMAE) or
monomethyl auristatin F (MMAF) efficiently target and kill a range of different
cancer cells. Notably, this targeting extends to both patient-derived explant (PDX)
cancer cell lines and
tumors, with the E3 MMAE and MMAF conjugates inhibiting PDX cell growth in vitro and with the E3 aptamer targeting PDX
colorectal tumors in vivo.