Therapeutic potential of lipin inhibitors for the treatment of cancer

Lipins are phosphatidic acid phosphatases (PAP) that catalyze the conversion of phosphatidic acid (PA) to diacylglycerol (DAG). Three lipin isoforms have been identified: lipin-1, -2 and -3. In addition to their PAP activity, lipin-1 and -2 act as transcriptional coactivators and corepressors. Lipins have been intensely studied for their role in regulation of lipid metabolism and adipogenesis; however, lipins are hypothesized to mediate several pathologies, such as those involving metabolic diseases, neuropathy and even cognitive impairment. Recently, an emerging role for lipins have been proposed in cancer. The study of lipins in cancer has been hampered by lack of inhibitors that have selectivity for lipins, that differentiate between lipin family members, or that are suitable for in vivo studies. Such inhibitors have the potential to be extremely useful as both molecular tools and therapeutics. This review describes the expression and function of lipins in various tissues and their roles in several diseases, but with an emphasis on their possible role in cancer The mechanisms by which lipins mediate cancer cell growth are discussed and the potential usefulness of selective lipin inhibitors is hypothesized. Finally, recent studies reporting the crystallization of lipin-1 are discussed to facilitate rational design of novel lipin inhibitors.