YSA acid – Cancer Peptides

YSA binds to the extracellular domain of ephrin type-A receptor 2 (EphA2) with high affinity and selectivity. YSA binding activates EphA2 and its tumour suppressing downstream signalling pathways (including inhibition of the PI3K/Akt and ERK pathways), and promotes receptor internalisation. EphA2 is highly expressed in many types of solid tumour, and the level of EphA2 expression is positively correlated with malignancy and poor prognosis in some cancer types. YSA has been shown to be an effective targeting peptide of chemotherapeutic drugs to EphA2 expressing tumours. YSA-drug conjugates are able to selectively target EphA2 expressing tumours, both activating tumour supressing downstream signalling pathways, and becoming effectively internalised by cancer cells to further increase the potency of the chemotherapeutic drug. YSA-drug conjugates have been shown to be dramatically more effective at inhibiting tumour growth than chemotherapy alone. Selective tumour targeting with YSA could also reduce the systemic toxicity caused by nonselective and highly toxic chemotherapy agents, and thus reduce adverse side effects of chemotherapy.