Fragments of RNA lost in the blood by cancer cells appear to reveal the presence of liver cancer at an early stage, when it can still be treated effectively. A study by Nanjing University (China).
Hepatocellular carcinoma (HCC), one of the most difficult cancers to treat as it is often diagnosed late, could be tackled more effectively in the future, thanks to a newly discovered genetic biomarker. The biomarker appears to reveal the presence of this liver tumour much earlier than is currently possible, and also tracks its progression over time. This would also make it possible to design treatment pathways with a higher probability of success from the outset.
The new marker is a fragment of one of the various types of RNA, tRNA (where t stands for transport). It is also more properly known as stRNA (small tRNA). It has long been known that these little nucleotide sequences (components of the genetic code) play a special role in the formation of tumours, and that their concentration increases significantly when the neoplastic process is in progress.
Some RNA fragments lost in the bloodstream by cancer cells have already been associated with specific cancers, but no link has been found with hepatocarcinoma until now. The gap is now being bridged by research by hepatologists at Nanjing University, China, who appear to have identified the genetic ‘fingerprint’ of this tumour, from its early stages (the so-called stage I). The fragment in question is called tRF-Gln-TTG-006, and can be identified with a simple blood test.
A promising biomarker to diagnose hepatocellular carcinoma early
According to a report in the scientific journal Frontiers of Medicine, the usefulness of tRF-Gln-TTG-006 emerged when comparing values found in 24 hepatocarcinoma patients with those of a control group of 24 healthy people. The sensitivity of the marker, which was tested in about 150 patients and the same number of healthy people, also proved to be high (around 80%) even for stage I tumours. These values are higher than the marker most frequently used today to monitor hepatocarcinoma - alpha-fetoprotein. Finally, further laboratory tests confirmed that tRF-Gln-TTG-006 is involved in processes of programmed cell death (apoptosis, in technical terms) and in the formation of colonies of multiplying cells: i.e. it is involved in the two classic factors of tumour growth. Cancer cells multiply excessively either because their duplication is incorrectly controlled, or because their programmed suicide is not triggered.
“According to our research,' confirms Yanbo Wang, professor at Nanjing University and coordinator of the research, “stRNA is a promising biomarker for early diagnosis of hepatocellular carcinoma”.
The study will be extended to a larger number of patients to conclusively prove its reliability.
The role of hepatitis viruses
Hepatocellular carcinoma is the most common primary liver tumour, i.e. one that develops directly from its own cells, known as hepatocytes. In most cases it is triggered by hepatitis B and C viruses, which, however, often have no obvious symptoms.