Scientists sequence genome of cancer-causing parasite

An international team of scientists has sequenced the genome and characterised the genes of the Asian liver fluke, Opisthorchis viverrini.

Writing in the journal Nature Communications, the researchers explained that the carcinogenic O. viverrini causes the hepatobiliary disease opisthorchiasis, which is itself linked to the fatal bile duct cancer cholangiocarcinoma (CCA). No vaccine is available, only one drug is used against the parasite and little is known about O. viverrini biology and the diseases that it causes. Such diseases affect millions of people in Asia.

Opisthorchis viverrini.

Lead investigators Dr Neil Young and Professor Robin Gasser, from the University of Melbourne, worked with an international team of experts to assemble and characterise the largest parasitic worm genome studied to date. Dr Young said the study “provides insight into how the fluke survives the hostile environment within the human bile duct and provides further evidence that these parasites release proteins that directly alter human tissue”.

The parasite is carried by snails and fish and infects humans, cats and dogs through the eating of raw fish. It migrates to the liver and bile duct, causing a range of chronic liver and gall bladder diseases including cancers. The researchers noted that “metabolic pathways in the parasite are highly adapted to a lipid-rich diet from bile and/or cholangiocytes”.

Professor Gasser stated, “Our new genome resource will underpin profound explorations of cancer-causing parasites and could lead to new treatments against parasites and parasite-induced cancers.”