Kaikōura Canyon's Cancer Connection
Hidden beneath the shore of Kaikoura is a canyon hosting exotic wildlife, which has led to medicinal discoveries.
It is no secret that Kaikoura is one of New Zealand’s best spots for whale and dolphin watching, but did you know about the other amazing wildlife below the water’s surface there have secrets to uncover?
The Pacific and Australian tectonic plates meet half a kilometre off the shoreline of Kaikoura, creating a trench that is 2 km deep. This underwater fissure, which is known as the Kaikoura Canyon, is host to exotic wildlife, making it an attractive field site for marine scientists.
Kaikoura Canyon Seabed Life (NIWA - https://www.niwa.co.nz/videos/kaikoura-canyon-seabed-life-0)
In 1988, research on the sea sponges found in the Kaikoura Canyon revealed they naturally produced an exquisite molecule known as halichondrin B. Although studies published a few years prior had demonstrated that halichondrin B is also produced by Japanese sea sponges, the researchers were only able to isolate miniscule amounts. Preliminary studies showed that halichondrin B has remarkable anticancer activity, but the limited amounts that were isolated meant that no further studies could be performed. So, when halichondrin B was found in the Kaikoura Canyon, researchers jumped at the chance to collect more.
The exquisite molecular structure of halichondrin B (By Jynto [CC0], via Wikimedia Commons)
Scientists from the National Cancer Institute (USA) teamed up with NIWA (NZ) to “mine” the sponge from the canyon and extract the active component, halichondrin B. Incredibly, one tonne of sea sponge material was collected from the Kaikoura Canyon and processed to result in just 300 mg of halichondrin B. It may not seem like much, it was plenty for the critical studies into the anticancer activity. In order to continue sustainable cultivation of the sea sponge, a marine farm was also set up.
Halichondria sp. sponge. By Minette Layne (Flickr) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
Decades of effort from marine biologists, chemists, and pharmacologists culminated in the creation of eribulin, a simplified synthetic analogue of halichondrin B with potent anticancer activity. Eribulin mimics the active part of the halichondrin B molecule, acting as an “antimitotic” chemotherapy agent. It was approved by the Food and Drug Association (FDA) in 2010 for chemotherapy of certain cancers, including breast cancer.
The development of eribulin from halichondrin B is a true success story for drug discovery inspired by nature. Who knows what other discoveries are waiting in the canyon?