Fatty Acids of Abyssal Echinodermata, the Sea Star Eremicaster vicinus and the Sea Urchin Kamptosoma abyssale: A New Polyunsaturated Fatty Acid Detected, 22:6(n-2).

Fatty acids (FA) of two species of abyssal Echinodermata-the sea star (Asteroidea) Eremicaster vicinus and the sea urchin (Echinoidea) Kamptosoma abyssale-from the Kuril-Kamchatka Trench, collected at depths of 5210 and 6183 m, were analyzed. Lipids of these deposit-feeding animals showed similar FA compositions: 20.05-16.08% saturated, 42.20-39.50% monoenoic, and 37.75-44.42% polyunsaturated FA, respectively. The contents of odd- and branched-chain FA were 17.35% and 8.80%, respectively. A significant part of FA was represented by uncommon FA such as 21:4(n-7), 22:4(n-8), 22:5(n-5), and 23:4(n-9), earlier discovered in deep-sea foraminifera. Also, the newly found acid, related to the ω2 family, Δ5,8,11,14,17,20-22:6(n-2), amounted 1.60% and 0.33% of total FA, respectively, for the two species. Such unusual FA composition of these abyssal species can be explained by the transfer and modification of FA from consumed foraminifera, which in turn, feed on bacteria.

High-throughput targeted screening in triple-negative breast cancer cells identifies Wnt-inhibiting activities in Pacific brittle stars.

Pro-proliferative oncogenic signaling is one of the hallmarks of cancer. Specific targeting of such signaling pathways is one of the main approaches to modern anti-cancer drug discovery, as opposed to more traditional search for general cytotoxic agents. Natural products, especially from marine sources, represent a largely untapped source of chemical diversity, which so far have mostly been screened for cytotoxicity. Here we present a pioneering pipeline of high-throughput screening of marine-based activities targeted against the Wnt signaling pathway, which is one of the key factors in oncogenic transformation, growth and metastasis in different cancers, including the devastating triple-negative breast cancer (TNBC) currently lacking any targeted therapies. This pipeline consisted of collection and characterization of numerous invertebrates during the SokhoBio expedition to the Kuril Basin in North Pacific, preparation of extracts from these specimen, and their screening in dedicated assays monitoring Wnt signaling in TNBC cells. This approach yielded a number of promising hits, including highly specific anti-Wnt activities targeting multiple levels within the Wnt pathway from Ophiura irrorata and other Pacific brittle stars.

New and Uncommon Fatty Acids in Lipids of Deep-Sea Foraminifera.

Fatty acids (FA) of agglutinating foraminifera of two genera, Bathysiphon and Rhabdammina, collected from a depth of 3307-3377 m in the Kuril Basin, Sea of Okhotsk, and adjacent deep-sea waters of the Pacific Ocean, were analyzed. In lipids of two Bathysiphon species, in addition to common FA typical for marine organisms, the uncommon ∆4 and ∆7 monoenoic acids and ∆4,7-dienoic acid were found in noticeable amounts. FA of two Rhabdammina species included also such uncommon acids as ∆5,8,11,14-21:4, ∆5,8,11,14-22:4, and ∆5,8,11,14-23:4, which are homologues to arachidonic acid. High levels of cis-vaccenic and arachidonic acids were typical for lipids of all the studied species. At the same time, we observed a substantial difference in FA composition between members of these two genera. Using GC and GC-MS of FAME, pyrrolidide and DMOX derivatives, the structures of 10 new FA were confirmed: ∆4-i-16:1 (1.1-0.6%), ∆7-i-21:1 (0.4%), ∆7-ai-21:1 (0.3-0.8%), ∆4,11-18:2 (0.3-0.9%), ∆4,7-20:2 (8.8%), ∆7,12-20:2 (0.4-0.6%), ∆4,7-21:2 (0.6%), ∆7,12-22:2 (6.4-2.1%); ∆5,8,11,14-22:4 (1.2-2.0%), and ∆5,8,11,14-23:4 (1.7-2.3%). The origin of the new FA and the role of foraminifera FA in deep-sea communities are discussed.