On 4 December at 15 Xuan Dung Ho will defend his doctoral thesis „Characterization of the genomic profile of osteosarcoma“.
Professor Aare Märtson (dr. med. (arstiteadus)), Institute of Clinical Medicine , University of Tartu
Professor Sulev Kõks (PhD (molekulaarne biomeditsiin)), Institute of Biomedicine and Translational Medicine, University of Tartu
Associate Professor Katre Maasalu (dr. med. (arstiteadus)), Institute of Clinical Medicine , University of Tartu
Professor Thomas Rado (PhD), Kadlec Clinic Hematology & Oncology, University of Washington, Seattle, WA, USA
Osteosarcoma (OS) is the most frequent type of primary bone cancer. About 3 cases per million population are diagnosed each year. It especially affects the young around puberty with slightly higher prevalence in male than in the female. The complaints of affected patients are very unspecific. Hence, the disease is easily neglected by the primary care doctors. Femur, tibia, and humerus are the most common sites of OS. It is a highly metastasized disease and lung is the most preferable metastatic site. The introduction of chemotherapy in the late 70s and early 80s has clearly improved the survival rate of OS and makes it possible for conservative operation. However, the prognosis of OS is still poor and unchanged since the 1980s. The cause and mechanism of OS are still poorly understood.
The number of studies on OS is growing dramatically with aims to understand its mechanism and to seek new therapeutic targets. Recently, genomic alterations in OS were studied with modern techniques. The differential expression of genes in OS has been reported with diverse findings, which may be due to the diversity of OS or design-associated limitations such as a small number of study subjects, variations in control groups, different laboratory protocols, and analysis techniques. We tried to overcome the present common limitations by analyzing paired samples of tumoral vs non-tumoral fresh bone specimens from the same patient and the paraffin blocks with RNA sequencing technique. Over 5000 genes were found to be differentially expressed between the normal and OS tissues. The most significantly differentially expressed genes were recognized to be further studied. The degradation of collagen seems to be an important mechanism of OS and should be further evaluated to serve as a biomarker for OS. The repetitive elements SAR, HSATII, and simple repeat (CATTC)n which were overexpressed in carcinoma in previous studies were also upregulated in OS and should be evaluated for biomarkers of this disease.