An international research team has identified around 120 new genes that contain mutations promoting cancer growth.
The discovery by a team of more than 60 scientists led by Michael Stratton of the Wellcome Trust Sanger Institute in Cambridge, Britain, made a significant addition to the 350 already known genes linked to cancer.
The researchers analysed 210 samples of cancerous tissue, surveying a family of 500 genes, called kinase genes linked to cell growth and division and sequencing more than 250 million letters of the DNA code.
They identified 158 mutations in around 120 genes that they believe can be implicated in cancer development, the Nature magazine reported in its latest issue published Thursday.
The number of mutations that appear to be involved in driving the growth of cancerous tumors was larger than expected, but ultimately the technique will allow scientists to acquire a complete catalogue of all the mutations involved in each class of cancer, according to Stratton.
"We have found a much larger number of mutated driver genes produced by a wider range of forces than we expected. It's important because the more cancer genes we find, the more targets we'll have in terms of potential new drugs," Stratton was quoted as saying.
The researchers in the study compared the genetic sequence of the DNA derived from a patient's tumor cells with the DNA of healthy cells from the same patient in order to find the mutations that are present only in the tumor cells, and which could be implicated in their growth.
All cancers are thought to result from an accumulation of mutations in one or another of the 30,000 genes in the human genome. These mutations cause a cell to multiply uncontrollably to form a tumor that can then spread to other parts of the body.
The next stage is to try to assess whether these mutations were directly involved in "driving" cancer development, or whether they were harmless "passenger" mutations, which accumulate in the body with age, according to the researchers.
They hope the study of the cancer genes will lead to the design and development of new drugs that specifically target the genetic errors that give rise to the growth of lethal cancer tumors.