Abstract 55: Further characterization of the human myoma tissue organotypic invasion assay
Authors: Salo Tuula A. , Pirilä Emma , Teppo Susanna , Nyberg Pia , Salo Sirpa , Lehenkari Petri , Risteli Juha 
Published: August 2012

Abstract
Background: The tumor microenvironment (TME) promotes cancer growth, invasion and spread. Our human tissue (uterus leiomyoma) derived three-dimensional organotypic model (Nurmenniemi et al. Am J Pathol, 2009), approximates the natural TME and was developed for invasion studies. Here, the aim was to further characterize and modulate our model in order to better understanding the role of TME in cancer invasion. Methods: Intact or extensively rinsed (14 days) myoma discs were used for analyzing the invasion depth of mobile tongue carcinoma (HSC-3) cells and the degradation of type III collagen (IIICTP). Both broad spectrum (GM6001 and E64) and more specific protease inhibitors (peptide G for MT1-MMP and CTT2 for gelatinases) were added into the culture media. Invasion depth of HSC-3 cells, co-cultured either with (a) phorbol 12-myristate 13-acetate (PMA)-differentiated leukemic THP-1 macrophages (PMAM); (b) with PMA, lipo-poly-saccharine (LPS) and interferon gamma (IFN-γ) differentiated pro-inflammatory macrophages (M1); or with (c) PMA, interleukin-4 (IL-4) and IL-13 differentiated pro-tumorigenic macrophages (M2); were analyzed. In a set of experiments, HSC-3 cells were co-cultured with normal gingival fibroblasts (GF), or with human bone marrow derived mesenchymal stem cells (MSC). In addition, soluble myoma tissue rinsing samples or myoma tissue species were analyzed with gel electrophoresis, immunohistology and Western blot analyses. Results: We found that HSC-3 cells invaded twice as deep, but degraded six times less type III collagen when cultured on top of intact compared to rinsed myoma discs. Peptide G, GM6001 and E64 significantly inhibited (p&lt;0.005), but CTT2 slightly induced HSC-3 invasion. In intact myoma, PMAM and MSC cells promoted HSC-3 cells invasion (p=0.002). M1 macrophage cells reduced (p=0.034), but M2 induced the HSC-3 invasion (p= 0.002). Intact myoma tissue contained invasion-inducting and anti-apoptotic matrix metalloproteinase-11 (MMP-11), and hypoxia- related factor lysyl oxidase (LOX). Both MMP-11 and LOX could be removed from the myoma with rinsing. Conclusions: Intact myoma tissue in vitro provides a rigid, hypoxic, antiapoptotic “highway” for effective invasion and mimics well the multicellular cancer environment in vivo. Collective or chain-type migration of carcinoma cells in myoma can be modulated by anti-proteolytic compounds, as well as co-culturing with mesenchymal or inflammatory cells. In intact myoma, proteolytic degradation of collagen matrix by invading cancer cells is not as crucial as in rinsed discs: rinsed myoma is deprived of invasion inductive TME factors. In conclusion, we highly recommend the use of the human myoma organotypic assay for the cancer invasion studies. It also has potential to be used for the identification and screening of anti-invasion cancer drugs.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 55. doi:1538-7445.AM2012-55