Tumor homing peptides (THPs) are cyclic or linear peptides of few amino acids having inherent property to recognize the tumor cells, which specifically bind to the receptors present on the tumor cells, tumor blood vessels or tumor lymphatic vessels. These can be utilized as major tool for targeted drug delivery particularly to cancerous cells, hence these are important for efficient cancer treatment. The present chapter summarizes the recent progression in the researches, databases and patents available in the field of cancer therapies utilizing THPs. It elucidates details about THPs; their modes of functioning, the molecules these may translocate; different methods of entry into the cells as well as diverse uses like gene correction and targeting of various tissues. Screening of THPs from phage library, natural occurrence of THPs in bacteria like Salmonella, Pseudomonas and engineered baculovirus have also been explicated. The specificity of THPs can be further enhanced by blending these with amphipathic conjugates, whereas the penetrability may be improved by adding cysteine or maleimidohexanoic acid to their N-terminal. Their half-life can also be increased by adding unnatural amino acids and modifying backbone or cyclization of THPs. For diagnostic and therapeutic purposes, several THPs have already been entered in different stages of clinical trials. THPs could serve as an ideal futuristic approach for targeting tumors based on their higher specificity, improved penetrability and half-life, acting as efficient delivery cargos for anticancer drugs and large therapeutic molecules.
Keywords: Angiogenesis, anticancer therapy, barrel stave pore, cancer therapies, CendR pathway, cell-penetrating peptides, clinical trials, inverted micelle, nanoparticles, phage display, RGD domain, toroidal pore, THP receptors, tumors, tumor homing peptides, vascular supply.