Experts target blood vessel growth in cancer battle
By Tan Ee Lyn
HONG KONG (Reuters) - Scientists in Australia have identified a gene that appears to be linked to blood vessel growth in tumors in mice and they hope the discovery can pave the way for improved treatment of cancer in people one day.
Current cancer therapies aim to kill blood vessels in tumors, which experts believe feed cancer cells, allowing them to multiply and stopping the immune system from attacking them.
In an article in Nature, the researchers said they identified a gene which appeared to be responsible for blood vessel growth in tumors.
"People now focus on blood vessels in cancer therapy and they try to kill them off. What I am showing is an alternative to just killing the blood vessels. We can modulate ... the blood vessels within the tumor, change the whole tumor environment and make it more susceptible for treatment," said Ruth Ganss at the Western Australian Institute for Medical Research.
The scientists used genetically-altered mice which developed pancreatic cancer, but half of them had the RGS5 gene missing.
"The tumors grow in both groups of mice, but ... the blood vessels looked very chaotic and abnormal (in the mice which had the gene) and they looked normalized when the gene was missing," Ganss said in a telephone interview.
The researchers later injected anti-cancer cells into both groups of mice and found that the mice without the gene lived longer and their tumor shrank.
"They were much more responsive (to treatment). These (anti-cancer) cells went right into the tumor and they shrank. The tumor burden was less and the mice survived longer," she said.
As for the other group of mice with the gene, Ganss said: "We inject them (anti-cancer cells) into the mice, but they don't reach the tumor in sufficient numbers to actually impact on the tumor at all."
The mice without the gene lived at least 10 weeks longer, before the experiment was stopped, and researchers found their tumors were about 50 percent smaller.
Ganss said the finding could help improve cancer therapy, but stressed that it should in no way be seen as a cure.
"We found a way where we could make a significant impact on the efficacy of this therapy and we understand why, but this is still a long way from curing cancer," she said.