A set of molecular scissors might one day be used to chop up a type of brain tumour that is a big cancer killer in the young, cutting out the need for expensive and risky surgery if Norwegian research proves successful. Mouldy Sioud and Dag Sorensen of the Institute of Cancer Research at the Norwegian Radium Hospital in Oslo figured that chopping up PKC-alpha would stop the cancer in its tracks and set about finding something to do the job. To stop their ribozyme from being chopped up itself by protective enzymes in the brain they simply swapped its natural building blocks for artificial versions that would not stop it working but that would make it unrecognisable to these damaging enzymes. The rats were injected with the molecular scissors directly into the tumour, and says Sioud this led to the death of almost all the cancer cells in less than three weeks treatment.
Malignant glioma is the third biggest cancer killer in the young and resists current treatments.
Julian Downward of the Imperial Cancer Research Fund is not convinced of the ribozyme's potential, however, 'It may well be that in the case of these gliomas, these researchers are managing to inhibit tumour growth with the anti-PKC ribozyme. Sioud adds that there are many gene products responsible for cancer cell proliferation and that stable ribozymes, such as his, could be used to treat other cancers too. He points out that pancreatic cancer is usually diagnosed too late for surgery, radiotherapy or standard chemotherapy but ribozymes might help reduce tumour size and allow, for instance, surgery to be carried out nevertheless. A compound usually associated with the killer disease tuberculosis could provide a clue to blocking further damage to the heart cardiac arrest survivors. A serendipitous conversation at a family gathering with his brother, Marcus a scientist at UCLA's School of Medicine, led to the two thinking about the possibilities of compounds that might reduced the damaging effects of repurfusion.