Boston University Scientists Identify Another Molecule for Lung Cancer Development

Science students at the University of Boston, School of Medicine are currently investigating a class of molecules known as microRNA (miRNAs) that control gene expressions and changes in gene expressions when smoking leads to lung cancer. This study appears on the Proceedings of the National Academy of Sciences Journal and may lead to a relatively new non-invasive biomarker for lung cancers caused by smoking (smoking-related lung diseases). The same group of Scientists previously discovered a gene expression biomarker that was capable of differentiating cytologically-normal bronchial epithelial cells in people with smoking-related lung cancers and in people without smoking-related lung cancers. This permits for the earlier detection of lung cancer in tissues that are sampled more than actually diseased lung cancerous tissues. The scientists conducted bronchoscopy on their clinical trial participants composed of smokers and non-smokers. The scientists examined samples of mirNA molecules extracted from airway epithelial cells through Bronchoscopy done on clinical trial participants and found that 28 MIRNA molecules were differently expressed among smokers than non-smokers. The scientists also discovered that by changing the expression of one such miRNA molecule, a whole sub-set group of mirRNA molecules could also be changed in the way they express among smokers. The image on the left above shows that as the # of biomarkers detected in Genes increases from 1 - 4, this increases the # of years it takes to diagnose clinical lung cancer. Thus, scientists are hoping that if 4 positive methylation biomarkers are found in the 1st or 2nd years, this can lead to diagnosis of lung cancer at its earliest stages, and thus doctors can recommend imaging therapies such as Bronchoscopy, CT scans or PET scans to accurately diagnose lung cancer and offer treatment options based on the evidence found. Common treatment options include chemotherapy, participation in clinical trials, lung transplants, thoracic surgery, palliative care (although this is more of a pain management technique, not pain relieving or curing).

Avrum Spira, MD & Associate Professor @ School of Medicine & Pathology quotes, "These studies suggest that smoking-dependent changes in miRNA expression levels mediate some of the smoking induced gene expression changes in airway epithelium and that miRNAs therefore play a role in the host response to environmental exposures and may contribute to the pathogenesis of smoking-related lung cancer. These microRNA changes may serve as more robust biomarkers in clinical samples given their role as regulators of multiple mRNAs and their relative resistance to degradation." The scientists hope their studies of miRNA molecules serve as relatively non-invasive biomarkers for smoking-related lung diseases.

Interesting Smoking Facts

It is estimated that over 1.3 billion people worldwide smoke on a daily basis, which leads to 5 million preventable deaths each year. Smoking is one of the biggest risk factors for lung cancer development, as the health of the lungs, blood flow within the body deteriorates. Infact, between 80% - 90% of lung cancer patients in the United States were past or current smokers. Because of lack of effective biomarkers that can identify the development of lung cancer at early stages, lung cancer, especially among smokers if often diagnosed at late stages when treatment methods are not effective. As the image above (right) shows, more people die from lung cancer than any other cancer. 5 year survival rate is 49% if Cancer is confined to the lungs, 16% if it spreads to the chest, and 2% of it spreads to other organs. This shows the importance of biomarkers & diagnosing development of lung cancers at early stages so that appropriate treatments can be recommended and the Cancer cured, as opposed to the lung cancer developing into advanced stages thefore becoming too late to be treated.