Title:Identification of Functional Peptides from Natural and Synthetic Products on Their Anticancer Activities by Tumor Targeting
Volume: 21
Issue: 21
Author(s): Joshua K. Ko and Kathy K. Auyeung
Affiliation:
Keywords:
Anticancer activity, cell-penetrating peptides, chemical and recombinant synthesis, cyclization, functional peptides,
intracellular drug delivery, natural products, tumor targeting.
Abstract: Cancer cells can express specific membrane proteins, which act as biomarkers for chemotherapeutic targeting.
Functional peptides possess unique properties that will ensure efficacy, selectivity, specificity and low toxicity when used
as therapeutic agents. Therapeutic peptides have been derived in treatment of cancers through improvement of cellular uptake,
drug targeting and vaccine development. Peptides from natural source have been used for chemoprevention and therapy
of various cancers. These include peptides derived from food, marine products, venom components and other animal
constituents. Besides, chemically- and recombinantly-synthesized peptides have also been produced and extensively studied
in contemporary applications. Improvement of tumor targeting is essential for chemotherapeutic development. This
can be achieved through enhancement of intracellular delivery and/or increased specific binding affinity to cancer cells by
pore-forming and cytotoxic peptides. Cytotoxic peptides such as the Bcl-2 family members can induce receptor-specific
binding to tumor cells and promote apoptosis by targeting lipid membranes. This approach has some limitations in targeting,
penetration and localization within tumors. Cell-penetrating peptides (CPPs) belong to a new class of tumor-targeting
peptides that can facilitate internalization of tumor markers and/or chemotherapeutic drugs. In order to overcome the
problem of serum instability in classical CPPs (e.g. Tat), newer classes of CPPs has been recently introduced. Nevertheless,
some cyclized CPPs can further enhance cellular uptake and binding selectivity when compared to activities of their
linear counterpart, especially when treating chemoresistant tumors. This review compiles the use of effective tumortargeting
peptides including novel CPPs that represents new therapeutic strategies for the treatment of cancers.
