Bowel cancer linked to fine-tuning ‘microRNA’

In collaboration with the Press Association

A tiny genetic ‘fine-tuner’ called a microRNA could play an important role in the development of bowel cancer, an international team of scientists suggest.

“If a drug can be developed against this target it offers the appealing prospect of shutting down multiple pathways of bowel cancer growth” - Dr Samuel Godfrey, Cancer Research UK

The molecule, known as microRNA 135b, was linked to several important cancer genes that are involved in the progression of the disease.

And the study, published in the journal Cancer Cell, could lead to new ways to target bowel cancer and shut down the effects of these cancer-causing genes in one hit.

Researchers based at The Institute of Cancer Research in London, the University of Glasgow and Ohio State University, USA tested for microRNA 135b in 485 patients with bowel cancer and found that levels were around four times higher in tumours than in healthy tissue.

Patients with the highest levels of microRNA 135b also survived the least long, opening up the possibility of using the molecule to identify patients with more aggressive forms of bowel cancer.

MicroRNAs are small strands of genetic material that regulate gene activity and are involved in many cellular processes.

Using cells grown in the lab, the team showed that a number of known cancer genes, such as APC, PI3KCA, SRC and p53, exercise their effects through microRNA 135b.

And when the researchers introduced a genetic block targeted to microRNA 135b into mice with bowel cancer they saw that tumour growth slowed.

Dr Samuel Godfrey, science information manager for Cancer Research UK - which part-funded the study - said: “This research shows that many of the faulty genes linked to bowel cancer use the same microRNA molecule to deliver their cancer-causing instructions, opening up an exciting avenue for developing new treatments.

“If a drug can be developed against this target it offers the appealing prospect of shutting down multiple pathways of bowel cancer growth simultaneously.”

Lead author Dr Nicola Valeri, Leader of the Gastrointestinal Cancer Biology and Genomics Team at The Institute of Cancer Research, London, said: “Patients with the highest levels of this molecule have the most difficult-to-treat cancers, and inhibiting the molecule in mice prevents tumours from growing.

“Although the research is at an early stage, our findings may have an important impact in the way we treat patients with bowel cancer in the future.”

Professor Owen Sansom, Deputy Director of The Cancer Research UK Beatson Institute at Glasgow University, said: “This exciting work shows a single microRNA can control multiple pathways that go wrong in colon cancer and offers the hope that in the future this could be targeted in patients that have colon cancer.”

The study also received funding from the Kimmel Cancer Foundation, The Marie Curie Actions Programme and a Scottish Senior Clinical Research Fellowship.

Copyright Press Association 2014


  • Valeri N, et al. (2014). MicroRNA-135b Promotes Cancer Progression by Acting as a Downstream Effector of Oncogenic Pathways in Colon Cancer, Cancer Cell, 25 (4) 469-483. DOI: