Peptide-Oleate Complexes Create Novel Membrane-Bound Compartments

BAMLET administration via drinking water inhibits intestinal tumor development and promotes long-term health

Though new targeted therapies for colorectal cancer, which progresses from local intestinal tumors to metastatic disease, are being developed, tumor specificity remains an important problem, and side effects a major concern. Here, we show that the protein-fatty acid complex BAMLET (bovine alpha-lactalbumin made lethal to tumor cells) can act as a peroral treatment for colorectal cancer. ApcMin/+ mice, which carry mutations relevant to hereditary and sporadic human colorectal cancer, that received BAMLET in the drinking water showed long-term protection against tumor development and decreased expression of tumor growth-, migration-, metastasis- and angiogenesis-related genes. BAMLET treatment via drinking water inhibited the Wnt/β-catenin and PD-1 signaling pathways and prolonged survival without evidence of toxicity. Systemic disease in the lungs, livers, spleens, and kidneys, which accompanied tumor progression, was inhibited by BAMLET treatment. The metabolic response to BAMLET included carbohydrate and lipid metabolism, which were inhibited in tumor prone ApcMin/+ mice and weakly regulated in C57BL/6 mice, suggesting potential health benefits of peroral BAMLET administration in addition to the potent antitumor effects. Together, these findings suggest that BAMLET administration in the drinking water maintains antitumor pressure by removing emergent cancer cells and reprogramming gene expression in intestinal and extra-intestinal tissues.

Double Emulsion Droplets as a Plausible Step to Fatty Acid Protocells

It is assumed that life originated on the Earth from vesicles made of fatty acids. These amphiphiles are the simplest chemicals, which can be present in the prebiotic soup, capable of self-assembling into compartments mimicking modern cells. Production of fatty acid vesicles is widely studied, as their growing and division. However, how prebiotic chemicals require to further yield living cells encapsulated within protocells remains unclear. Here, one suggests a scenario based on recent studies, which shows that phospholipid vesicles can form from double emulsions affording facile encapsulation of cargos. In these works, water-in-oil-in-water droplets are produced by microfluidics, having dispersed lipids in the oil. Dewetting of the oil droplet leaves the internal aqueous droplet covered by a lipid bilayer, entrapping cargos. In this review, formation of fatty acid protocells is briefly reviewed, together with the procedure for preparing double emulsions and vesicles from double emulsion and finally, it is proposed that double emulsion droplets formed in the deep ocean where undersea volcano expulsed materials, with fatty acids (under their carboxylic form) and alkanols as the oily phase, entrapping hydrosoluble prebiotic chemicals in a double emulsion droplet core. Once formed, double emulsion droplets can move up to the surface, where an increase of pH, variation of pressure and/or temperature may have allowed dewetting of the oily droplet, leaving a fatty acid vesicular protocell with encapsulated prebiotic materials.

Long-term prevention of bladder cancer progression by alpha1-oleate alone or in combination with chemotherapy

Bladder cancer is common and one of the most costly cancer forms, due to a lack of curative therapies. Recently, clinical safety and efficacy of the alpha1-oleate complex was demonstrated in a placebo-controlled study of nonmuscle invasive bladder cancer. Our study investigated if long-term therapeutic efficacy is improved by repeated treatment cycles and by combining alpha1-oleate with low-dose chemotherapy. Rapidly growing bladder tumors were treated by intravesical instillation of alpha1-oleate, Epirubicin or Mitomycin C alone or in combination. One treatment cycle arrested tumor growth, with a protective effect lasting at least 4 weeks in mice receiving 8.5 mM of alpha1-oleate alone or 1.7 mM of alpha-oleate combined with Epirubicin or Mitomycin C. Repeated treatment cycles extended protection, defined by a lack of bladder pathology and a virtual absence of bladder cancer-specific gene expression. Synergy with Epirubicin was detected at the lower alpha1-oleate concentration and in vitro, alpha1-oleate was shown to enhance the uptake and nuclear translocation of Epirubicin, by tumor cells. Effects at the chromatin level affecting cell proliferation were further suggested by reduced BrdU incorporation. In addition, alpha1-oleate triggered DNA fragmentation, defined by the TUNEL assay. The results suggest that bladder cancer development may be prevented long-term in the murine model, by alpha1-oleate alone or in combination with low-dose Epirubicin. In addition, the combination of alpha1-oleate and Epirubicin reduced the size of established tumors. Exploring these potent preventive and therapeutic effects will be of immediate interest in patients with bladder cancer.

Lipid bilayer composition as a determinant of cancer cell sensitivity to tumoricidal protein-lipid complexes

Complexes formed by the alpha1 N-terminal peptide of alpha-lactalbumin and oleic acid (alpha1-oleate) interact with lipid bilayers. Plasma membrane perturbations trigger tumor cell death but normal differentiated cells are more resistant, and their plasma membranes are less strongly affected. This study examined membrane lipid composition as a determinant of tumor cell reactivity. Bladder cancer tissue showed a higher abundance of unsaturated lipids enriched in phosphatidylcholine, PC (36:4) and PC (38:4), and sphingomyelin, SM (36:1) than healthy bladder tissue, where saturated lipids predominated and the lipid extracts from bladder cancer tissue inhibited the tumoricidal effect of the complex more effectively than healthy tissue extracts. Furthermore, unsaturated PC in solution inhibited tumor cell death, and the complex interacted with giant unilamellar vesicles formed by PC, confirming the affinity of alpha1-oleate for fluid membranes enriched in PC. Quartz Crystal Microbalance with dissipation monitoring (QCM-D) detected a preference of the complex for the liquid-disordered phase, suggesting that the insertion into PC-based membranes and the resulting membrane perturbations are influenced by membrane lipid saturation. The results suggest that the membrane lipid composition is functionally important and that specific unsaturated membrane lipids may serve as "recognition motifs" for broad-spectrum tumoricidal molecules such as alpha1-oleate.