Antibiotic hailed as cure for cancer by scientists

Doctors in Glasgow killing leukaemia stem cells with pneumonia treatment

An antibiotic used to treat pneumonia was hailed yesterday as a new and unexpected cure for leukaemia.

Doctors at Cancer Research UK’s Beatson Institute in Glasgow found that the antibiotic tigecycline, marketed as Tygacil, kills chronic myeloid leukaemia (CML) stem cells when used in conjunction with a cancer-growth blocking drug which is the standard first-line treatment of patients with the disease.

They say their study, published yesteday, demonstrates the “exciting” effectiveness of combining tigecycline with the cancer growth-blocker imatinib.

Dr Vignir Helgason, of Glasgow University, joint lead author of the study, said: “We were very excited to find that when we treated CML cells with both the antibiotic tigecycline and the TKI drug imatinib, CML stem cells were selectively killed.

We believe that our findings provide a strong basis for testing this novel therapeutic strategy in clinical trials in order to eliminate CML stem cells and provide cure for CML patients.”

Using cells isolated from CML patients, the researchers showed that treatment with tigecycline, an antibiotic used to treat community-acquired bacterial pneumonia and complicated skin infections, is effective in killing CML stem cells when used in combination with imatinib.

The study also showed the novel drug combination “significantly delayed relapse” in pre-clinical models of human CML.

The Glasgow doctors say they believe the two drugs together offer a “potentially enhanced cure rate” for CML.

Chronic myeloid leukaemia (CML) is a form of blood cancer that turns normal blood stem cells into leukaemic stem cells, or CML stem cells. These CML stem cells then produce large numbers of leukaemic cells which, if left untreated, are fatal.

At present, CML patients are treated with tyrosine kinase inhibitors, otherwise known as TKIs, such as imatinib. TKIs are effective at killing the majority of the leukaemic cells, but they do not kill the CML stem cells from which the disease arises.

As a result, TKIs alone rarely cure the disease but hold its advancement at bay. Therefore, most patients need to remain on TKIs for the rest of their lives to control the disease, with the additional risk of developing drug resistance.

Professor Eyal Gottlieb, at the UK Beatson Institute, said: “Our work in this study demonstrates for the first time that CML stem cells are metabolically distinct from normal blood stem cells, and this in turn provides opportunities to selectively target them.”

Professor Karen Vousden at Cancer Research UK said: “It’s exciting to see that using an antibiotic alongside an existing treatment could be a way to keep this type of leukaemia at bay, and potentially even cure it.

“If this approach is shown to be safe and effective in humans too, it could offer a new option for patients who at the moment face long-term treatment with the possibility of relapse.”

The pioneering research was driven, in part, by the work of scientist the late Professor Tessa Holyoake, director of Glasgow University’s Paul O’Gorman Leukaemia Research Centre.

Professor Holyoake, who died last month from breast cancer, aged 54, is named as a co-author of the paper.

Researchers at Cancer Research UK’s Beatson Institute in Glasgow made the breakthrough discovery.

The pioneering research was driven by the late Professor Tessa Holyoake.