Body secretes protein that destroys cancer, finds Indian doc - Health & Science - The Times of India
Body secretes protein that destroys cancer, finds Indian doc
July 25, 2009
NEW DELHI: Last year, he hit the headlines for creating the world's first breed of super mice, which are resistant to
all forms of cancer. Now,
Mumbai-born, US-settled, Dr Vivek Rangnekar, professor of radiation medicine at the University of Kentucky, has in another breakthrough discovered that the Par-4 protein (mass killer of cancer cells) is produced within the human body itself and spreads through circulation to distant organs.
This finding will now help scientists look at ways to naturally increase the secretion of the protein, for example, by certain natural diets and develop resistance to the growth of cancer. Scientists can also develop approaches to safely inject the Par-4 protein to inhibit cancer.
The team headed by Dr Rangnekar has also found that Par-4 protein is capable of killing cancer cells, when applied from outside. Till this discovery, scientists believed that Par-4 protein has to be present inside cancer cells to kill them.
Since it isn't easy to deliver large amounts of the protein inside cancer cells, scientists have been studying other methods to target and kill cancer cells.
Par-4, after being secreted by human tissues, has also been found to kill only cancer cells. It didn't harm normal cells, proving they aren't toxic. The presence of large amounts of the Par-4 protein in the super mice had made them completely immune to cancer. Not only did they not develop tumours, they even lived longer.
According to Dr Rangnekar, who is associate director of University of Kentucky's Markey Cancer Center, what these findings mean for the future is that it may not be necessary to use invasive or genetic approaches to inhibit the growth of cancer.
``Par-4, secreted inside the human body by the kidney, lung and prostate, can now be developed so as to inject the protein to treat cancer. Not only primary tumours, but also metastatic tumours that have spread to other tissues should be killed by the Par-4 protein,'' Dr Rangnekar, who spent over 25 years of his life in Matunga, Mumbai, told TOI.
``Increased Par-4 protein in circulation, in the blood and serum of the super mice, is one of the reasons they are resistant to cancer,'' Dr Rangnekar added. According to his team, a person is susceptible to cancer when the amount of this Par-4 protein secreted by the cells of that individual is low and inadequate.
``This needs to be tested on an individual basis. The next step is to test whether human cancer can be prevented/treated by increasing the amount of protein produced,'' the doctor said.
And how will the team do that? ``Either by injecting Par-4 protein or by trying different diets,'' Dr Rangnekar said.
Reporting this breakthrough in the journal `Cell' on Friday, Dr Rangnekar, who studied at Don Bosco School and Indian Education Society School in Dadar, added, ``The novelty is that the Par-4 molecule binds to its receptor GRP78 on the surface of a tumour cell and then triggers a biological process called apoptosis or cell suicide, killing the cancer cells.''
Is the finding that Par-4 gene is present inside humans new? Dr Rangnekar said, ``We knew previously that Par-4 is expressed (present) inside human tissues and cells. This new finding shows that it is also secreted and in circulation in humans, just like it is in circulation in the blood/serum of super mice.''
So does this mean humans can in the future become completely invulnerable to cancer? ``Yes, one can extrapolate that humans have the secret inside themselves to be invulnerable to cancer. The levels within individuals may vary, and we have to find ways to increase those levels naturally. We are starting studies on the role of natural dietary compounds to increase secretion.''
``It was a pleasant surprise when we noticed that Par-4 protein is secreted by human cells. This means it is not necessary to make genetic modifications, or to employ recombinant viruses, to deliver the Par-4 gene to cancer cells,'' he added.
Rangnekar first discovered the Par-4 gene in 1993. In 2007, his team introduced the gene into a mouse embryo, creating the super mouse.