London, Mar 16 : Researchers at Harvard University have discovered a fundamental mechanism of tumor growth, a breakthrough that may lead to more effective and less toxic treatments for cancer.
The scientists have identified an enzyme which enables cancer cells to consume the huge quantities of glucose they need to fuel uncontrolled growth.
The research team has described how starving cancer cells of the enzyme curbed their growth.
The key enzyme, pyruvate kinase, comes in two forms, but the team found that only one - the PKM2 form - enables cancer cells to consume glucose at an accelerated rate.
When they forced cancer cells to switch to other form of pyruvate kinase in the lab by knocking out production of PKM2, their growth was curbed.
When the cells were injected into mice, they were much less able to produce tumors.
The fact that proliferating cancer are able to consume glucose at a much higher rate than normal cells was first discovered by the German Nobel prize-winning chemist Otto Warburg more than 75 years ago.
He also showed that the amount of glucose the cells needed to keep their vital signs ticking over was minimal, allowing them grow and divide at the prodigious rate usually associated with foetal cells.
The researchers said the exact chemistry behind glucose metabolism probably varied between types of cancer.
"Because PKM2 is found in all of the cancer cells that we have examined, because it is not found in most normal adult tissues, and because it is critical for tumor formation, this form of pyruvate kinase is a possible target for cancer therapy," Nature quoted lead researcher Professor Lewis Cantley, as saying.
"We don't yet know whether these findings can be applied to human cancers outside the lab, so more research is needed before we can consider developing cancer treatments that target this process," Dr Joanna Peak, of the charity Cancer Research UK, said.
The study is published in the journal Nature.