Peptides as Potential Anticancer Agents.

Cancer consists of heterogeneous multiple cell subpopulation which at a later stage develop resistant phenotypes, which include resistance to pro-apoptotic stimuli and/or cytotoxic resistance to anticancer compounds. The property of cancerous cells to affect almost any part of the body categorizes cancer to many anatomic and molecular subtypes, each requiring a particular therapeutic intervention. As several modalities are hindered in a variety of cancers and as the cancer cells accrue varied types of oncogenic mutations during their progression the most likely benefit will be obtained by a combination of therapeutic agents that might address the diverse hallmarks of cancer. Natural compounds are the backbone of cancer therapeutics owing to their property of affecting the DNA impairment and restoration mechanisms and also the gene expression modulated via several epigenetic molecular mechanisms. Bioactive peptides isolated from flora and fauna have transformed the arena of antitumour therapy and prompt progress in preclinical studies is promising. The difficulties in creating ACP rest in improving its delivery to the tumour site and it also must maintain a low toxicity profile. The substantial production costs, low selectivity and proteolytic stability of some ACP are some of the factors hindering the progress of peptide drug development. Recently, several publications have tried to edify the field with the idea of using peptides as adjuvants with established drugs for antineoplastic use. This review focuses on peptides from natural sources that precisely target tumour cells and subsequently serve as anticancer agents that are less toxic to normal tissues.