Rosana Risques

My name is Rosana Risques and I'm from Spain. I got my Ph.D. in Barcelona, working on genomic instability in colorectal cancer. I moved to San Diego for a postdoc in microarrays development and after that I decided to come back to the cancer research field again. That's why I joined Peter Rabinovitch's lab, around 2 years ago. I found the projects in the lab very interesting, especially the study of the relation between telomere shortening, cancer and aging. I really like the people in the lab too, and the great location next to the water!

Telomeres protect the end of the chromosomes, but shorten with every cell division. Telomere shortening promotes chromosomal instability and can thereby facilitate tumor progression. Since telomeres shorten progressively with age, this provides an attractive link between aging and cancer. Our studies focus on the measurement of telomere length in human samples in order to identify if short telomeres can predict cancer development and to better define the role of telomere shortening in aging. We work with two main diseases: ulcerative colitis and Barrett's esophagus. They are characterized by inflammation of the epithelium of the colon and the esophagus, respectively, that eventually can lead to dysplasia and in a few cases, to cancer. Therefore these diseases are excellent models to study tumor progression. My two main projects consist of the analysis of telomere length of biopsies and lymphocytes from ulcerative colitis and Barrett's esophagus patients, although we've also analyzed colon samples of normal individuals, liver biopsies and cell lines, in collaboration with other groups. To measure telomere length we use Quantitative PCR. This technique allows the use of very small amounts of DNA, which is essential when working with human biopsies. It is very fast and high-throughput, which is very convenient when hundreds of samples are to be processed. Using this technique we have already confirmed some previous interesting results obtained by Quantitative FISH; another technique for telomere length measurement that we use in the lab, but it is more time consuming and less high-throughput. We are also developing an assay to measure telomerase activity (the enzyme that elongates telomeres in vivo) using quantitative PCR. The analysis of telomere length and telomerase activity in large and well documented sets of patients susceptible of cancer development will provide very useful information to better understand the role of telomeres in tumor progression and in aging.