Reading science news on national newspapers is a very different experience from reading science news as a scientist looking at scientific journals. Every week, we read about flashy headlines about science that is not (or at least not yet) up to scratch but that sounds interesting or familiar to the general reader. There are countless examples of this, from tomatoes being the cure for cancer, curry preventing malignancy and, last week, purple potatoes being the cure for colorectal cancer (a tomato and purple potato salad sounds good right about now). As a scientist, the depressing thing is that while we are busy discussing these new “studies” that are almost always based on very very thin evidence, there is some truly amazing, awe-inspiring science being published every day that is based on very solid data and that the public should know about.
For instance, instead of thinking about purple potatoes, this week we could have all been talking about the way cigarette smoke literally changes our DNA and makes it more likely for cancerous mutations to arise. In a way, smoke is “fertilizing the soil” for dangerous cancerous mutations to arise. The authors show that lung cells of cigarette smokers begin to “turn off” (or “silence”) tracts of their DNA, which leads to those regions of DNA undergoing a special chemical modification known as “methylation”. These changes are known as “epigenetic changes” because they change the way DNA is active even though they do not directly change the structure of DNA itself. Interestingly, the regions of DNA that are “silenced” include genes that usually keep particular mechanisms in the cell under control. In many ways, the cell silences the activity of its”breaks” and therefore is set for a wild, accelerated ride. Cells whose “breaks” have been “silenced” start dividing uncontrollably, which is how they inevitably catch a deadly cancer mutation, which means that they will turn into a malignant tumor and start spreading throughout the body. These scientists have performed studies both in vitro (ie being cells in a dish) as well as in vivo (ie in mice that have been treated with cigarette smoke). What’s more, they have confirmed their findings looking at data taken from lung cancer patients who were smokers, and shown that the mechanism they have discovered is actually relevant in the clinic.
Since this work is based on solid data, it has real potential to help patients in the clinic. Since we now know at least one mechanism through which smoking causes lung cancer, we can develop drugs that block it and prescribe it to people who are trying to quit smoking to try and protect them from the adverse effects of smoking. What’s more, this is even further evidence that smoking does cause lung cancer, something that public policy experts can take into account when allocating funds to stop-smoking policies or in trying to get tobacco banned from public spaces. In short, this work is not only shining light on a striking effect of cigarette smoke, but is good, solid science we can trust. It is worth reading, enjoying and thinking about.