Scientists battle cancer drug resistance

A main cause of failure in the treatment of cancer is the development of drug resistance by the cancer cells. Much research is already under way to investigate ways of reducing or preventing chemotherapy (CT) resistance. Now, scientists from Kingston University, London, the UK, have begun a three-year study to analyse why cancer patients become resistant to treatments designed to fight the disease. The team has been awarded £99,000 to investigate why some tumours are sensitive and respond to treatments, and why other tumours do not. The study, funded by cancer charity, BRIGHT (Better Research into Gastrointestinal Cancer Health and Treatment), will look at existing treatments for colorectal cancer (CRC).

Experts from Kingston's Faculty of Science will work with specialists at Royal Surrey County Hospital to examine tumour specimens from CRC patients. They aim to identify signs or markers that could indicate how patients respond to treatment with anticancer drugs. The scientists will also investigate whether cancer stem cells (SCs) play an important role in the progression of CRC, and could be responsible for the poor response or development of resistance to treatment with anticancer drugs.

The study could help local health authorities to target drugs more effectively and spare those who will receive no significant benefit from treatment with what are often expensive drugs. The researchers want to investigate why it is that after several cycles of CT, resistance to the CT agents occurs. Ultimately, the team hopes that the results of the investigation will improve survival among cancer patients. It should also help scientists to develop new drugs to target those patients who do not respond well to medication currently available.

Further research in the field of resistance to cancer therapy could come from a new exclusive licence between Clarient and Minerva Biotechnologies. Minerva has granted Clarient the exclusive right to develop and commercialise a test that identifies the MUC1* protein, a biomarker researchers believe may be implicated in the spread of many cancers, including breast cancer. Early research has demonstrated that MUC1* may play a role in developing resistance to cancer drugs, which means that if scientists can block MUC1*, patients may be able to overcome resistance to a drug and, once again, be offered that therapy.

The MUC1 story has garnered a great deal of attention recently with Minerva's discovery that MUC1 is in an altered form, called MUC1*, on embryonic SCs and cancer cells. This is the first direct evidence that cancer cells grow by hijacking a normal SC mechanism that usually exists in a dormant state on healthy adult cells. Minerva has compelling evidence that cancer cells that grow resistant to anticancer drugs do so by producing more MUC1*. A recent study by Minerva outlined how the blocking of MUC1* can reverse an acquired resistance to cancer drugs, increasing the therapeutic choices for certain solid tumours.

Alice Rossiter - Editor, Cancer Drug News