The pharmacology and regulation of T type calcium channels: new opportunities for unique therapeutics for cancer.

T type calcium channels are implicated in a fascinating array of physiological and pathophysiological phenomena, as reviewed extensively in this issue of Cell Calcium. It is also evident from this timely collection of papers that knowledge about T channels is nascent. This creates the exciting potential to explore an uncharted territory for new insights into important physiological processes and associated diseases. Equally exciting and perhaps more important is the opportunity to exploit the developing understanding of T channels to design new therapeutic approaches to diseases that are now intractable to varying degrees. This review will focus on the controversy surrounding the proposed novel functions for and means of regulation of T type Ca2+ channels, particularly with regard to the potential role of pharmacologic modulation of T type Ca2+ channels in cytostatic cancer chemotherapy. In addition, we will concentrate on recent studies of the molecular pharmacology and physiology of T type channels, since these areas (molecular pharmacology [T.N. Heady, J.C. Gomora, T.L. Macdonald, E. Perez-Reyes, Molecular pharmacology of T-type Ca2+ channels, Jpn. J. Pharmacol. 85 (2001) 339-350.]; physiology [E. Perez-Reyes, Molecular physiology of low-voltage-activated t-type calcium channels, Physiol. Rev. 83 (2003) 117-161.]) have been very well-reviewed and the reader is referred to these authoritative sources.