Poster No. 16 Tumor SBI-0206965 Margin as a Unique Zone, which can be Molecularly Distinguished, in TME Baek Gil Kim 1 , Suki Kang2, Nam Hoon Cho1,2,3 1 Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea Republic, 2 Department of Pathology, Yonsei University College of Medicine, Seoul, Korea Republic, 3 Global 5-5-10 System Biology, Yonsei University, Seoul, Korea Republic It is very important to distinguish between tumor and normal tissue for accurate pathology diagnosis and

effective cancer treatments. Particularly after surgical removal of cancer, residual tumor tissue often causes high recurrence and mortality rate as well as poor prognosis. For this reason,

the demand for defining clear tumor tissue margin at a molecular level has been raising. We therefore suggest that molecular tumor margin must be considered in tumor microenvironment (TME), especially in the aspect of extracellular matrix (ECM) which is a main component of TME, as well as tumor cells. Defining the portraits of tumor margin facing normal tissue can be a prerequisite step for further application of molecular margin to eliminate the chance of tumor recurrence. Breast cancer is the best model for TME remodeling study because of frequent accompanied desmoplasia and clinical requirement for minimized operation. In our study, we made a tissue classification as follows, rear tumor burden, tumor margin predominantly facing the normal tissue, and before normal learn more tissue remote from the tumor burden. Differential ECM expression in each tissue was compared by using ECM array based on real-time RT-PCR, and further validated by western blot. On analysis of ECM transcript gene array, LAMA3, which is a subunit of laminin332, was significantly overexpressed in tumor margin in comparison with adjacent tumor burden or normal tissue in 6 breast cancer samples.

Fibronectin 1 and SPARC (osteonectin) were shown to be downregulated in tumor margin. E-cadherin was downregulated in the tumor margin in contrast to upregulated N-cadherin. In conclusion, tumor margin could be independently unique zone differentiated from rear tumor burden and remote normal tissue, which appears dynamic and functionally most active zone during TME remodeling. Poster No. 17 The Human L3MBTL4 Gene, a Tumor Suppressor Gene Involved in Breast Cancer Development Lynda Klouche 1,2 , Soraya Moulessehoul2, Max Chaffanet1, Daniel Birnbaum1 1 Laboratoire d’oncologie Moleculaire, Centre de Recherche en Cancerologie. Institut Paoli-Calmettes.Umr 891, Marseille, France, 2 Laboratoire de Selleckchem MK-1775 Biotoxicologie, Universite Djillali Liabes, Sidi-Bel-Abbes, Algeria L3MBTL4 gene, a human homolog of Drosophila lethal(3) malignant brain tumor(D-l(3)mbt), lies in a region of chromosome arm 18p that is frequently deleted in breast cancer cells.