In 2001, the journals Science and Nature simultaneously published the results of a decade or more of groundbreaking scientific research – the Human Genome Project. But what is the Human Genome Project? Why was it done? And most importantly, what have we learnt from it?
Inside almost every one of our cells are chromosomes made up of DNA. DNA is a long, twisted molecule made up of units of 4 chemicals called adenine, thymine, cytosine and guanine and (A, T, C and G respectively), plus some sugar and phosphate molecules to hold it all together. We’ve known for many years that small sections of DNA, called genes, provide the instructions to make different proteins, and proteins are important because they are involved in just about every chemical, mechanical and structural function in the body.
The primary aim of the Human Genome Project (HGP) was to “spell out” the sequences of As, Ts, Cs and Gs for every single human gene. It was hoped that if we can do this and discover what a “normal” gene looks like, then we would also discover the genetic mutations and abnormalities that cause human diseases. Not only that, but by mapping the location of each gene on each chromosome, we might be able to use targeted drug and gene therapy to treat or even cure some of these diseases.
The announcement, in February 2001, that the human genome had been sequenced was front page news. After years of trying, and $3 billion of funding, it had finally been done. Researchers heralded the beginning of a “golden age” for genomic research, and the media were in a frenzy speculating on all the terrible diseases that may now be cured, all the wonderful new drugs that might be developed. But then, after the hype, it all went quiet.
So what has the HGP achieved in the last 10 years? We still haven’t cured cancer, or AIDS, or Alzheimer’s, and stem cell therapy is still a rather experimental treatment for some diseases rather than the miracle cure-all we hoped it would be. Was the HGP a waste of time and money?
Of course the answer to this is “no”. Though, as a result of the HGP, medicine has not advanced as much as we might like in the last decade, our underlying understanding of genomics has made great leaps and bounds. As The Economist’s Science Editor Geoffrey Carr wrote recently, the race (between rival research teams Celera and the International Human Genome Sequencing Consortium) to sequence the human genome “was not a race to the finish line, but a race to the starting line”.
So what have we learned from the HGP? Well, the very fact that the entire human genome – some 3 billion As, Ts, Cs and Gs long – could be sequenced and mapped is in itself a marvellous achievement for scientific research, and the sequencing process has been refined so that it is now much quicker, cheaper and more efficient. Despite humans being one of the most complex organisms on Earth, we’ve learned that the human genome is much smaller than we originally thought – we have around 22,000 genes, in comparison to the very recently-sequenced and very tiny water flea (Daphnia pulex), which has 31,000.
Though the head of pharmaceutical company Novartis once quipped that the HGP had yielded “data, data everywhere, and not a drug, I think”, we are now beginning to see advances in medicine too. While we have not yet witnessed a “revolution” in terms of “the diagnosis, prevention and treatment of most, if not all, human diseases”, as predicted by then-President Bill Clinton in June 2000, we have pinpointed the genetic defects that cause around 850 diseases and this is slowly but surely leading to advances in their treatment. Thanks to HGP research, several new drugs for cancer, osteoporosis and lupus are now beginning to enter the market after a decade of trials, and genetic screening is becoming more widely available for a greater range of diseases.
Despite the deficit in new discoveries that have been sensational enough to rouse the interest of the general public, the Human Genome Project and the ongoing research stemming from it, is still plugging away and helping to increase our overall understanding of genomics. If sequencing the human genome was a sprint to the start line, the race from here on is a marathon, but one that will ultimately impact greatly on biology, medicine and science as a whole.