The use of drug cocktails has become a widely adopted strategy in clinical cancer therapy. Cytotoxic drug cocktails are often administered based on maximum tolerated dose (MTD) of each agent, with the belief of achieving maximum cell kill through tolerable toxicity level. Yet, MTD administration may not have fully captured the therapeutic synergism that exists among the individual agents in the drug cocktail, as the response to a cocktail regimen, that is, whether the effect is synergistic or not, could be highly sensitive to the concentration ratios of the individual drugs at the site of action. It is important to realize that the inherently different pharmacokinetic profiles of the individual agents could have significant influence on the response to an anti-cancer drug cocktail by dictating the amount of the individual agents reaching the tumor site and therefore the concentration ratios. Furthermore, the individual agents may have unfavorable pharmacokinetic interactions that add to the difficulty in determining the therapeutic and/or toxicological effects of the drug cocktail. In this review, we will focus on how lipid-based nanoparticulate systems could address the above issues associated with anti-cancer drug cocktails. Specifically, we will highlight the use of liposome systems as the means to control and coordinate the delivery of various anti-cancer drug cocktails, encompassing conventional chemotherapeutics, chemosensitizing agents and molecularly targeted agents.

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Our study provided proof-of-concept evidence to deliver synergistic combination of bioactive lipid to achieve complete remission in AML.

Abstract. Colon cancer represents one of the most common solid tumors in adults. Although 5-fluorouracil (5-FU) and irinotecan have been frequently administered in colon cancer patients, low response rates to these single drug therapies were reported. It is therefore imperative to search for new targeted combination therapies that are effective. In this study, we investigated the anti-cancer effect of safingol as a single agent or in combination with irinotecan using HT-29 and LS-174T colon cancer cells as our in vitro models. As a single agent, safingol was more potent than irinotecan and 5-FU, with IC 50 values of 2.5±1.1 μM and 3.4±1.0 μM achieved in HT-29 and LS-174T cells, respectively. However, protein kinase C (PKC) was not inhibited with concentrations of safingol which could induce substantial cell kill. The combination of safingol/irinotecan at 1:1 molar ratio was found to be additive in HT-29 cells (CI=0.94) and synergistic in LS-174T cells (CI=0.68), and resulted in concentration-and time-dependent down-regulation of p-PKC and p-MARCKS. The drug effect of the safingol/irinotecan combination was further modulated in the presence of a PKC stimulator (phorbol 12-myristate 13-acetate) or a PKC inhibitor (staurosporine). Furthermore, the 1:1 safingol/irinotecan combination inhibited the adhesion of colon cancer cells to the extracellular matrix 4-h post-treatment. Taken together, modulation of the PKC pathway could be a possible molecular basis for the observed synergism of the safingol/irinotecan combination, and these results demonstrate the therapeutic potential of this drug combination in colon cancer treatment.