siRNA technology to arrest growth of cancers

Syed Akbar
Hyderabad: An Indo-US team has developed a new medical
technology that helps in arresting the growth and spread of cancers
through a simple injection. It is safe and has no side effects unlike
in radiation or chemotherapy. The tumour stops growing within 45 days
of receiving the injection.

The technology, based on gene therapy, has been successfully
demonstrated in animal models for cancers of the brain. The Indian
members of the team are now working on breast cancer since India has
one of the highest incidences of breast cancer in the world.

“Our gene therapy is based on siRNA (small interfering ribonucleic
acid). Once siRNA is introduced into the body of a cancer patient
through an intravenous injection, it starts showing results within 45
days. The other alternative is to inject the siRNA into the tumour
directly. Both the methods worked in animals. Currently we are in
phase III trials, and once we receive the necessary approval, we will
take up human trials,” said Dr Ramarao Malla, a member of the Indo-US
team that worked on brain cancers in the USA.

Dr Rama Rao, who conducted research on brain cancers while he was with
the University of Illinois, USA, is currently working on gene therapy
for breast cancer in India at the department of biochemistry, Gitam
University, Visakhapatnam. “As part of our gene therapy strategy we
have used siRNA since it targets two key proteins, uPAR (urokinase
type plasminogen activator receptor) and cathepsin B, in brain cancer.
These proteins are responsible for the growth of tumours both in the
brain and in the breast. Thus, the same strategy works for breast
cancer too,” Dr Ramarao pointed out, adding that the team is further
researching whether the proteins are involved in other cancers too.

In animal models, a single dose injection prevented the growth and
metastasis (spread to neighbouring tissues). Once the human trials
begin, the exact dosage will emerge, he added. This technology has
helped in arresting the progression of brain cancer by as much as 85
per cent compared to radiation treatment.

Breast cancer is the most frequently diagnosed cancer and the leading
cause of cancer death among women, accounting for 23 per cent of the
total cancer cases and 14 per cent of the cancer deaths worldwide.
Breast cancer is now also the leading cause of cancer death among
women in India, a shift from the previous decade during which the most
common cause of cancer death was cervical cancer.

The research will also hold promise for the treatment of prostate
cancer, the leading cancer in men, comprising 17 per cent of the total
new cancer cases and 23 per cent of the total cancer deaths, Dr Rama
Rao said.