Scientists stumble on novel method to battle cancer

Scientists may have found a way to reprogramme cancer, after stumbling on the ''software'' for turning off deadly cell mutations. 

Florida researchers have discovered what they say is a surprising link between a biological ''microprocessor'' - a group of proteins that help activate key molecules called microRNAs - and proteins that help cells stick together.

The team from Mayo Clinic says its findings, outlined this morning in the journal Nature Cell Biology, open the way to ''a new strategy for cancer therapy''.

Senior researcher Panos Anastasiadis said the team was examining the ''clinical implications''. ''We have focused on the most aggressive form of breast cancer - inflammatory breast cancer - and bladder cancer.''

Lead author Antonis Kourtidis said the study brought together previously unrelated research fields - cell-to-cell adhesion, and microRNA biology - to resolve ''a longstanding problem that was baffling scientists''. The mystery involved two ''adhesion'' proteins that help cells form into the tissues that line blood vessels and organs. Both proteins had long been considered tumor suppressors, but studies found them in cancerous cells.

Researchers concluded the two proteins had a Jekyll and Hyde character - a good side maintaining normal cell behaviour, and a bad side driving tumors - but they did not know why.

The team says it has now found the answer. A ''binding partner'' called PLEKHA7 targets the top of cells, working with two enzymes to harness microRNAs and ensure adhesion proteins behave themselves. But if PLEKHA7 is absent, the two proteins ''switch sides'', targeting the bases of cells and sparking tumours. ''We believe (this) is an early and somewhat universal event in cancer,'' Dr Anastasiadis said.

''(It) produces the equivalent of a speeding car that has a lot of gas and no brakes. (This represents) an unexpected new biology that provides the code, the software, for turning off cancer.''

The team is trialling ways of restoring microRNA levels in cancer cells to normal. Initial experiments on cultured cancer cells have proven ''very promising''.

Anastasiadis said system-wide administration of microRNAs could trigger side effects, so direct injection offered the best hope. ''We have focused initially on lung and bladder cancer because local therapy is feasible in these tumours.

''If results are promising, we will work on better delivery options (such as) nano particles.''