Australian cancer news

'Trojan Horse' Therapy Kills Cancer Cells
Posted on: Monday, 29 June 2009, 06:36 CDT

A new "trojan horse" therapy designed to kill off cancer has been developed by a team of Australian scientists, Reuters reported.

By first injecting a bacterially-derived nano cell into an active cancer cell, the cancer cell becomes disarmed and vulnerable when it is exposed to chemotherapy drugs.

The "trojan horse" therapy differs from traditional treatment in that it specifically targets cancer cells with chemotherapy, instead of both cancerous and healthy cells.

In the past two years, Sydney scientists Dr. Jennifer MacDiarmid and Dr. Himanshu Brahmbhatt of EnGeneIC Pty Ltd. have accomplished 100 percent survival in mice with human cancer cells by practicing the "trojan horse" therapy.

Human clinical trials of the cell delivery system are scheduled to begin in the upcoming months at the Peter MacCullum Cancer Center at the Royal Melbourne Hospital and The Austin at the University of Melbourne.

The therapy, as described in the latest issue of the Nature Biotechnology journal, observes mini-cells termed EDVs (EnGenelC Delivery Vehicle) attach and penetrate the cancer cell.


The purpose of the first round of mini-cells, or siRNA, is to release ribonucleic acid molecules, which shut down the production of proteins that make the cancer cell resistant to chemotherapy.

A second round of EDV cells is then recognized by the cancer cell and releases chemotherapy drugs, exterminating the cancer cell.

"The beauty is that our EDVs operate like 'Trojan Horses' They arrive at the gates of the affected cells and are always allowed in," said MacDiarmid.

"We are playing the rogue cells at their own game. They switch-on the gene to produce the protein to resist drugs, and we are switching-off the gene which, in turn, enables the drugs to enter."

In 2006, RNA interference, or RNAi, was the basis of the Nobel Prize in medicine and continues to be one of the most popular topics in biotechnology research. Its purpose in development is to calm genes to blame for producing disease-causing proteins.

Biotechnology companies are widely searching for ways to re-work RNA to block genes that generate disease-causing proteins found in cancer, blindness, or AIDS.

After traditional drug therapy, Brahmbhatt informed, a large percentage of cancer cells die but a small number of the cells can generate proteins that cause cancer cells to be resistant to chemotherapeutic drugs.

"Consequently, follow-up drug treatments can fail. The tumors thus become untreatable and continue to flourish, ultimately killing the patient," said Brahmbhatt.

"We want to be part of moving toward a time when cancers can be managed as a chronic disease rather than being regarded as a death sentence," he said.

The article in the Nature journal indicated that the mini-cells were "well tolerated with no adverse side effects or deaths in any of the actively treated animals, despite repeated dosing."

"Significantly, our methodology does not damage the normal cells and is applicable to a wide spectrum of solid cancer types," said MacDiarmid.

"The hope is that the benign nature of this EDV technology should enable cancer sufferers to get on with their lives and operate normally using out-patient therapy."

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