Editorial [Hot Topic: Recent Advances in Cancer Chemotherapy-Part I (Guest Editor: Diwan S. Rawat)]

Cancer has been one of the most deadly diseases characterized by uncontrolled cell divisions and the ability of these cells to spread either by invasion, or by metastasis. It has overtaken the heart disease which is one of the commonest causes of death in some developed countries. Cancer affects people at all ages, but risk tends to increase with age. Worldwide over 11 million people are diagnosed with cancer and 7 million deaths are reported annually. It is estimated that there will be 16 million new cases every year by 2020. In spite of improved understanding of molecular biology of cancer and advances in oncology, replacement of conventional therapies like chemotherapy and radiation therapy still remains impossible. Natural product has been a source of new drugs since ancient times and about 60% anti-cancer drugs available today, are either derived from natural sources or their synthetic analogues. Some of the notable plant based drugs that has entered in the clinical trials are taxol, obtained from the bark of pacific yew trees-Taxus brievifolia, camptothecin isolated from the Chinese ornamental tree Camptpotheca acuminata. Camptothecin showed great promises in the 1970's, but its clinical use was hampered due to its severe side effects. The structure activity relationship studies conducted on camptothecin derivatives resulted in the discovery of anti-cancer drugs such as topotecan and irinotecan. Microorganisms have also been the source of the key drugs for cancer chemotherapy and some of the microorganism based anticancer drugs are bleomycins, dactinomycin, mytomycine, anthracylinones, calchiamycin, dynamycine, daunomycin and doxorubicin (adriamycin). All of these compounds were introduced to the clinic before their mode of action had been determined. The anti-cancer activity of most of these compounds is due to their ability to cleave the DNA through different modes. This especial issue entitled “Recent advances in cancer chemotherapy” provides glimpses of recent development on anti-cancer drugs that includes synthetic, semi-synthetic, natural products and their clinical applications. The articles are written by leading scientists in the field which clearly shows that there are indeed fascinating and fundamentally important problems to be addressed and that considerable advances towards their understanding have been made. The present issue deals with the anticancer agents of natural sources or their synthetic or semi-synthetic derivatives. Enediyne class of compounds has received much attention of the scientist in recent years due to their potential use in the anti-cancer drug discovery programme. Shao et al. describes the recent progress, particularly in the area of biosynthesis, immunoconjugates and clinical studies of lindamycin. The pharmacological applications of lidamycin in cancer therapy and its potential use as anti-cancer agents have also been discussed. Dembitsky et al. presented a comprehensive literature collection on the acetylenic anticancer natural products. The review presents anti-cancer activity of more than 300 acetylenic metabolites isolated from terrestrial and aquatic organisms. Parmar et al. presented an excellent literature collection on the natural polyphenolic compounds as antiinvasive agents. Prof. Beck-Sickinger described the role of radiolabelled receptor binding peptides as a new class of radiopharmaceuticals for tumor scintigraphy and to treat cancers by using peptide receptor radiation therapy (PRRT). Lastly, Bifulco et al. discuss preliminary clinical observation that indicates a possible use of N6-isopentenyladenosine as anticancer drug. Finally, I would like to thank to all contributors and reviewers who helped me to bring this issue in its present shape. In particular, to the authors for generously contributing their expertise in the preparation of this issue. I greatly appreciate the honor given to me by Prof. Michelle Prudhomme, Editor-in-Chief, Anti-Cancer Agents in Medicinal Chemistry, in entrusting me as a Guest Editor of this special issue. Anti-Cancer Agents in Medicinal Chemistry is a high-standard international journal through which important discoveries in the area of anti-cancer research becomes available to the scientific community. I hope that readers will enjoy reading this issue and it will stimulate interactive research with other specialist areas. The mutual interaction among scientist of different disciplines will be helpful for the development of more effective drugs, diagnostics and therapies for the treatment of cancer.