Melatonin as a Therapeutic Agent for the Inhibition of Hypoxia-Induced Tumor Progression: A Description of Possible Mechanisms Involved.

Hypoxia has an important role in tumor progression via the up-regulation of growth factors and cellular adaptation genes. These changes promote cell survival, proliferation, invasion, metastasis, angiogenesis, and energy metabolism in favor of cancer development. Hypoxia also plays a central role in determining the resistance of tumors to chemotherapy.

Current approaches in identification and isolation of cancer stem cells.

Cancer stem cells (CSCs) are tumor cells with initiating ability, self-renewal potential, and intrinsic resistance to conventional therapeutics. Efficient isolation and characterization of CSCs pave the way for more comprehensive knowledge about tumorigenesis, heterogeneity, and chemoresistance. Also a better understanding of CSCs will lead to novel era of both basic and clinical cancer research, reclassification of human tumors, and development of innovative therapeutic strategies.