Demethoxycurcumin: A naturally occurring curcumin analogue with antitumor properties

The eradication of cancer in a patient remains an elusive challenge despite advances in early detection and diagnosis, chemo- and immunotherapy, pinpoint radiation treatments, and expert surgical intervention. Although significant gains have been made in our understanding of cancer cell biology, a definite cure for most cancers does not exist at present. Thus, it is not surprising that the research and medical communities continue to explore the importance and therapeutic potential of natural products in their multimodality cancer treatment approach. Curcuminoids found in turmeric are one such class of natural products that have been extensively investigated for their potential to halt the progression of cancer cell proliferation and, more important, to stop metastasis from occurring. In this review, we examine one curcuminoid (demethoxycurcumin [DMC]) largely because of its increased stability and better aqueous solubility at physiological pH, unlike the more well-known curcuminoid (curcumin), which is largely unabsorbed after oral ingestion. The present review will focus on the signaling pathways that DMC utilizes to modulate the growth, invasion, and metastasis of cancer cells in an effort to provide enhanced mechanistic insight into DMC's action as it pertains to brain, ovarian, breast, lung, skin, and prostate cancer. Additionally, this review will attempt to provide an overview of DMC's mechanism of action by modulating apoptosis, cell cycle, angiogenesis, metastasis, and chemosensitivity. Lastly, it is hoped that increased understanding will be gained concerning DMC's interactive role with microRNA-551a, 5' adenosine monophosphate-activated protein kinase, nuclear factor-κB, Wnt inhibitory factor-1, and heat shock protein 70 to affect the progression of cancer.