S'pore researchers unlock the genetic code of cancer-causing liver parasite

Liver fluke parasite (Opisthorchis viverrini).
PHOTO: S'pore researchers unlock the genetic code of cancer-causing liver parasite

SINGAPORE - An international team of scientists from Singapore, Thailand, China and Australia has cracked the genetic code of a liver fluke parasite, furthering research into the development of treatments for bile duct cancer - a condition caused by the parasite.

The parasite Opisthorchis viverrini infects millions in Asia, and it is classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC).

This parasite is endemic to some countries in Southeast Asia, including Northeastern Thailand, Laos and Cambodia, the researchers said. Despite its prevalence, there is no vaccine and only one drug available to counter the parasitic worm.

The fluke enters the human body through the ingestion of raw or undercooked contaminated fish. Once in the small intestine, the worm migrates to the liver's bile ducts, where it lodges, feeds and matures.

It is not known for certain how the fluke causes cancer. One widely accepted hypothesis is that the fluke secretes a protein mimicking the human growth hormone, granulin, which is extremely potent at stimulating cell growth and proliferation.

The granulin-like proteins secreted by flukes subsequently cause host cells to proliferate uncontrollably, leading to tumour growth.

By mapping out the genes of this parasite using a unique DNA analysis technique developed at A*STAR's Genome Institute of Singapore (GIS) , researchers aim to better understand its molecular pathways. This will help them identify new biological markers, which could potentially be developed into powerful diagnostic tools and effective treatments for parasite-specific diseases.

This research was part of an international collaboration involving team leads, Dr Niranjan Nagarajan and Professor Patrick Tan from Sinagpore's GIS, and Dr Neil Young and Professor Robin B. Gasser from Australia's University of Melbourne, and others from Thailand and China.

"This work builds on our earlier work to complete the picture of host and pathogen genetics of cholangiocarcinoma. These new genomic resources provide a foundation for systems biology investigations of host-pathogen interactions, with a view to uncovering new treatment strategies," Prof Tan said.

yamadak@sph.com.sg