Research Findings

Breakthrough in War on Cancer

Breakthrough in War on Cancer

New wonder drug began life in SA lab

Cancer treatment has medical world abuzz

The global search for a cure for cancer has taken a giant leap forward thanks to a chance discovery made in a South African lab many years ago.

Instead of killing cancer cells, using chemotherapy or radiotherapy, the new approach — called “epigenetic therapy” — is to wake up sleeping genes in those cells, which instruct them to change back to normal.

A massive international clinical trial, the results of which were published in medical journalLancet in March this year, showed that the survival rate of some cancer patients was boosted from 26%, using ordinary chemotherapy, to over 50% using “epigenetic therapy”.

In May, Cape Town-born Professor Peter Jones received the US’s highest cancer research award for pioneering not only the therapy, but an entire new field of science. Jones was appointed head of a US cancer dream team, and awarded a grant of R72-million.

This week, Dr Carl Albrecht, head of Research for the Cancer Association of South Africa and a former colleague, said Jones’s work represented “the great new hope” in the war on cancer. “I would not be surprised in the least if Jones were to win the Nobel prize,” he said. “This could prove to be one of South Africa’s greatest gifts to the world,”.

Jones, who is Director of the Norris Comprehensive Cancer Centre in California, said cancer’s new frontier was born in a small laboratory in Parow, Cape Town, in the late ’70s. And it happened by accident.

Wanting to see whether cancer drugs could trigger cancer in basic (as opposed to specialised) human cells, Jones i nstead found that an ordinary human cell which he’d treated with an obscure cancer drug known as “aza-c” was beating, like a heart.

He discovered that the drug had somehow switched on genes which turned the basic cell into a muscle cell. If it could do that, Jones thought, then surely it could also switch on genes in cancerous cells to turn them back into healthy ones.

“I can still remember being there in the lab at Tygerberg when my grad student ran in and said, ‘My God, I just saw these cells twitching.’ It was completely accidental,” he said.

Jones said “epigenetic” drugs based on aza-c had been approved in the US and Europe last year, and had since doubled the life expectancy of “tens of thousands” of mostly elderly people with certain blood cancers. Lancet reported that 358 patients in 15 countries were involved in the international trial, which found that those receiving aza-c survived an average of 9.4 months longer than those on conventional treatment, “with a two-year survival rate that was nearly doubled”.

Jones said the challenge for “the years ahead” was to wake up genes in all other kinds of cancer cells to instruct them to return to normal.

Jones’s wonder drug was approved in South Africa in February. However, he warned that it had so far only proved effective in two diseases in humans: a “pre-cancer” called MDS and a kind of leukaemia called AML.

The cost of a single month’s treatment is R60 000 — and some medical aids will pay for the new therapy. Farrel Tobiansky, a Johannesburg GP, is borrowing money from family and friends to fund epigenetic treatment for his father, Joe, 78, who has MDS and was given less than five years to live.

“This is an unbelievably good drug — the statistics on survivability are fantastic; there’s reason to hope he’ll have more than (10 years),” said Tobiansky. “But now that we learn that it was actually discovered in South Africa, it’s doubly outrageous that one major medical aid refuses to fully fund it.”

Jones, 62, conducted his “seminal work” at Stellenbosch Medical School in the ’70s. He emigrated to the US in the ’80s. He regularly visits his two brothers and sister in South Africa.

Last year, he received the AG Oettle prize, South Africa’s highest cancer research award. But, said Jones, “my frustration in Johannesburg last year was that I felt the people didn’t realise that funding from the then South African National Cancer Association — which could only invest peanuts for research — actually led to a whole new field of science in the world”. “Something was done in South Africa that has launched a serious new hope.”

What is epigenetic therapy?

If DNA is the full script for the play that creates all human cells, “epigenes” are the directors who tell the actors when to start and stop reading their lines.

They are chemicals which flick the “on-off switch” to genes within the DNA, telling genes in the liver to make liver cells, or switching on adult cells when we reach puberty, for example.

Up to now, there has not been much doctors could do about bad copies of that script — where mutated genes are passed from parent to child — except to destroy the cell.

But researchers are learning that they can wake up actors who have been “turned off” for no reason.

For reasons not yet fully understood — but often triggered by factors like diet — the epigenes sometimes deactivate a perfectly good gene, which can lead to the cell becoming cancerous.

The new therapy simply seeks to turn those genes on again, which can change a cell completely within as little as 10 days.

Source: Rowan Philp Published:Jul 25, 2009. The Times
http://www.thetimes.co.za


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