Monday, April 20, 2009

Calcutta brain shows nano test to fight cancer

New Delhi, April 20: A young biochemist, an alumnus of Presidency College, Calcutta, now at the Massachusetts Institute of Technology, has demonstrated a potentially novel way of combating diverse cancers.

Sudipta Basu, a post-doctoral researcher at the Harvard-MIT Health Sciences and Technology division, has designed tiny particles to ferry molecules that interfere with cancer mechanisms and make tumours respond better to chemotherapy.

In a series of laboratory and animal studies, Basu and his colleagues led by another Indian, Shiladitya Sengupta, have shown that this new strategy can kill lung cancer and skin cancer cells in the laboratory and block the growth of skin tumours in mice.

Their findings are encouraging enough for them to suggest that their technique may emerge as a previously untested route for cancer treatment.

The researchers engineered nanoparticles — particles so tiny that their sizes are measured in billionths of a metre — in such a way as to impart them with a stealth feature to evade the human immune system, but selectively seek out tumours.

They used these nanoparticles to deliver special molecules that suppress the activity of an enzyme called MAPK which has been implicated in several cancers in humans, including colon, pancreatic, liver and lung cancers.

“This enzyme is also involved in normal functions of the body,” said Sengupta. “The key challenge was to target abnormally-activated enzyme selectively inside cancer cells. We’ve done this with these stealth nanoparticles,” he told The Telegraph.

The findings appeared today in the US journal Proceedings of the National Academy of Sciences.

Post-doctoral fellow Basu, who had graduated from Presidency College and completed a Masters from IIT Kanpur, also presented the work today at a conference in Denver.

Basu said some doctors have expressed an interest in trying out the technique, especially against liver cancer.

In their studies on mice, the nanoparticles not only blocked the growth of skin tumours called melonomas, but also enhanced the anti-tumour efficacy of an anti-cancer drug called cisplatin.

Sengupta cautioned that drugs that target the MAPK enzyme mechanism are still under clinical trials so human trials combining anti-MAPK molecules and the nanoparticle approach could be a few years away.

“The future lies in using innovatively designed complex nanoparticles that will specifically home into tumours and deploy drugs that rectify abnormal cancer generating signals,” said Raghunath Mashelkar, former director general of India’s Council of Scientific and Industrial Research, who was a visiting professor at the Harvard-MIT HST division in 2007 when the project was conceived.

Sengupta, who heads the Laboratory for Nanomedicine at the HST division has cofounded a company, Cerulean Pharmaceuticals, which is trying to develop nanomedicines for cancer.

Sengupta had studied at the All India Institute of Medical Sciences, New Delhi, and the University of Cambridge, before joining MIT in 2001, where he is now assistant professor and head of laboratory of nanomedicine.

“The field of cancer chemotherapy is heading towards targeted treatment that will shut down cancer-causing pathways,” Sengupta said. “In another 5 to 10 years, this would be the mainline approach to treating cancer.”

Source