Riproximin is a recently discovered type II ribosome inactivating protein with potential for treating cancer

摘要: The development of new anticancer drugs is a salient problem and the traditional use plants potentially rich source information for detecting molecules with antineoplastic activity. Riproximin recently detected cytotoxic type II ribosome inactivating protein high selectivity certain tumor cell lines. Its activity was recognized as main component in plant powder used by African healers treating cancer. By ribulose bisphosphate carboxylase gene sequencing analysis, identified to be derived from Ximenia americana. cDNA sequence riproximin identified, modeled contain one A- B-chain, respectively, reliable purification procedure kernels X. americana established. displays but differential antiproliferative panel human rodent cancer lines, concentrations inhibiting proliferation 50% (IC50 values) that diverge factor 100. Consistent colorectal pancreatic liver metastasis models rats. mechanism action determined based on cellular uptake followed its A-chain prompted depurination 28S ribosomal RNA induction unfolded response. Riproximin's specificity depended B-chain connected binding surface glycans, presence which crucial subsequent internalization into cells cytotoxicity. These N- O-glycans include bi- tri-antennary NA structures (NA2/NA3) well Tn3 (clustered Tn antigen). found crosslink proteins O-glycan structure, thus indicating both types sites B chain. Due this crosslinking ability, expected show prominent cytotoxicity towards expressing both, NA2/NA3 clustered structures. Apart properties riproximin, has been known some medical uses medicine, including various infections.