Minerval^® (2OHOA) is Lipopharma’s lead compound, showing a powerful anti-cancer effect coupled with absence of toxicity or side effects. 2OHOA is an orally administered synthetic analogue of oleic acid that regulates cellular activity by modulating the membrane lipid structure of cancer cells. In short, due to its structural properties and to the important alterations found in the membranes of cancer cells, the compound activates sphingomyelin synthase (SMS), which results in an important increase in the levels of membrane sphingomyelin (SM) and diacylglycerol (DAG), which have been found to be significantly reduced in cancer cell membranes. At the same time, the activation of SMS reduces the levels of other SMS substrates, such as phosphatidylethanolamine (PE) and phosphatidylcholine (PC), restoring PE:SM ratio to the levels found in non-cancer cell membranes.  As a consequence of this regulation of the structure and composition of membrane lipids, the location and activity of a number of peripheral signal transduction proteins in cancer cells is also regulated, normalizing the activity of critical signalling pathways for the proliferation of cancer cells, mainly the Ras/MAPK pathway

1) Minerval^® activates SMS

Minerval^® induces a direct activation of sphingomyelin synthase (SMS), an enzyme responsible for the synthesis of several lipid classes found in cell membranes as SM, DAG, PE or PS. This activation is highly dependent on structural characteristics of Minerval^®, can be observed very rapidly (only 5 minutes after treatment) and is dose and time dependent.

Minerval^® activates SMS in glioma cells (U118). The sphingomyelin synthase (SMS) substrate, NBD-Cer, was rapidly transformed into the fluorescent SM derivative, NBD-SM, upon treatment with Minerval® (2OHOA). This result, in addition to structure-function experiments, indicates a direct interaction between Minerval and SMS.

2) SMS activation results in a significant and specific regulation of membrane lipids in cancer cells

By activating SMS Minerval^® regulates the structure, composition and functions of cancer cell membrane lipids. In particular it induces a very important rise in the levels of sphingomyelin (SM), only in cancer cell membranes. Levels of diacylglycerol (DAG), another product of SMS, are also increased, while levels of other SMS substrates (PE and PC) are significantly lowered.

Minerval^{® (}2OHOA) induces marked increases of SM levels in human glioma (U118, 1321N1, SF767), lung cancer (A549) and leukemia (Jurkat) cells, but not in normal cells (MRC5). In this context, SM is found at lower levels in cancer cells studied and its membrane concentration is normalized by 2OHOA treatments.

Membranes of cancer cells exhibit markedly lower SM levels than those found in non-cancer cells, as well as very important differences in the PE:SM molar ratio. This molecular feature of plasma membrane appears to be a critical condition for tumorgenesis (most likely in connection with Ras-associated signaling, which is over-activated in a wide range of cancers). In this context, Minerval^® is an specific SMS activator that produces restoration of SM levels (and of the PE:SM ratio) and normalization of growth signals

3) Normalization of membrane lipids in cancer cells translocates Ras from the membrane to cytosol, inactivating the MAPK pathway which causes inhibition of cancer cell proliferation and selective autophagic cell death (in glioma)

Normalization of SM levels in cancer cell membranes leads to the translocation of Ras from the membrane to the cytosol of the cells, inhibiting (“normalizing”) the Ras/MAPK signaling pathway. Due to lack of activation from the MAPK proteins, the PI3K/Akt pathway and the Cyclin/CDK/E2F-1 pathway are also downregulated, whereas the Cyclin-dependent kinase inhibitors (CDKI), p21 and p27 levels are markedly increased, further inactivating E2F-1 via hypophosphorylation of the RB, resulting in an important knock-down of DHFR, a critical protein needed for DNA synthesis.

Minerval® induces membrane-to-cytosol translocation of Ras in glioma cells (SF767) after 10m. (Confocal 1) and 24h. incubation (Confocal 2).

Minerval® induces marked and significant reductions in the phosphorylation status (i.e., activity) of all the proteins of the MAPK pathway and inhibits DHFR expression at the protein and mRNA levels.