Bioactive peptides for anticancer therapies

Abstract

Cancer is a serious concern in public health worldwide. Numerous modalities including surgery, radiotherapy, and chemotherapy, have been used for cancer therapies in clinic. Despite progress in anticancer therapies, the usage of these methods for cancer treatment is often related to deleterious side effects and multidrug resistance of conventional anticancer drugs, which have prompted the development of novel therapeutic methods. Anticancer peptides (ACPs), derived from naturally occurring and modified peptides, have received great attention in these years and emerge as novel therapeutic and diagnostic candidates for cancer therapies, because of several advantages over the current treatment modalities. In this review, the classification and properties of ACPs, the mode of action and mechanism of membrane disruption, as well as the natural sources of bioactive peptides with anticancer activities were summarised. Because of their high efficacy for inducing cancer cell death, certain ACPs have been developed to work as drugs and vaccines, evaluated in varied phases of clinical trials. We expect that this summary could facilitate the understanding and design of ACPs with increased specificity and toxicity towards malignant cells and with reduced side effects to normal cells.

Keywords: anticancer peptide; antimicrobial peptide; apoptosis; natural resources.

Figure 1.. (A) Multipurpose bioactivities exhibited by peptides from natural resources, (B) Physicochemical and physiological factors of bioactive peptides that determine their anticancer activities.

Figure 2.. Proposed signaling pathways for induced apoptosis of cancer cells by pro-apoptotic peptides. Apaf-1: apoptotic protease activating factor 1; Apo2L: Apo2 ligand; Diablo: direct IAP binding protein with low pI; DR: death receptor; FADD: Fas associated via death domain; IAP: inhibitor of apoptosis protein; TRAIL: tumour necrosis factor-related apoptosis-inducing ligand.

Figure 3.. Schematic illustration of ACP structures containing α-helices (A), β-sheets (B), extended structures (C) or cyclic loops (D). ACP: anticancer peptide.

Figure 4.. Lists of bioactive peptides with potentials for anticancer therapies via varied mechanisms.

Figure 5.. Schematic illustration of different mechanisms of anticancer peptides for cell entry.