Sea sponges share secrets

A collaborative biodiscovery research project between the Australian Institute of Marine Science (AIMS) and the US National Cancer Institute (NCI) has turned up some new compounds from sea sponges that show anticancer activity. Called chondropsins, the compounds are a type of chemical called macrolide lactams and are produced by three species of Australian sea sponge, including one species from the Great Barrier Reef.

Research at the NCI has shown that the chondropsins have an unprecedented profile of activity against a panel of 60 tumour cell types, including highly potent activity against osteosarcoma (bone cancer) cell lines.

Further research showed that the drug potential of these compounds may come from their ability to target enzymes, vacuolar (V)-ATPases, which are responsible for regulating pH inside and outside cells.

Some V-ATPases play a role in the development of cancer and bone diseases such as osteoporosis and a wide range of other conditions such as Alzheimer’s, viral infections, diabetes and cardiovascular disorders.

According to Libby Evans-Illidge, AIMS project leader and manager of the institute’s marine bioresources library, previous attempts to develop V-ATPase therapeutics have failed due to problems with toxicity.

“V-ATPases occur in most cells and are essential for normal healthy cellular processes. Previous leads were too toxic for use because they disrupted all V-ATPases indiscriminately. The exciting thing about the chondropsins is that they appear to selectively attack only certain types of V-ATPases, with low toxicity to others,” said Evans-Illidge.

The sponge samples were collected and provided to the project by the AIMS Bioresources Library, under permits and benefit sharing agreements which ensure there will be an equitable monetary return to Australia if the chondropsins make it into the clinic.

Expressions of interest by parties with the capability to further explore and develop the therapeutic potential of these compounds are being invited by AIMS. They will offer access to the full intellectual property portfolio, along with a sustainable supply of the compounds to support the next phase of research and development.

While sponge supply may be sourced from the wild or aquaculture initially, if the chondropsins prove their worth and succeed through to the clinic, they will need to be produced synthetically.