Gene Expression Profiles of a Progression Model of Human Ovarian Cancer

We have earlier reported the establishment of a comprehensive in vitro panel of 19 isogenic cell lines from a patient with Grade IV serous adenocarcinoma (Bapat et al. Cancer Research. 2005). In this study, one of the cell lines termed as A4 at early passes (less than ~20) was assessed as being non-tumorigenic since it failed to exhibit anchorage independence growth in soft agar and form tumors in nude mice. After further culture (more than 20 passages in vitro), the cells expressed all features suggestive of transformation including capabilities of anchorage independence growth, clonogenecity and reproducibility of the human disease in mice models as assessed through tumor and ascites formation in nude mice, and serial transplantion of tumor-derived cells over 3-4 mouse generations. The tumors generated in nude mice were also identified to be histologically similar to the primary tumor of the patient. A4 cells thus represent a single tumorigenic clone that underwent transformation in vitro, and hence may be considered to be an ovarian tumor progression model. Two-condition experiment, Samples for hybridization included – (i) Non-tumorigenic A4 cells at passage 15 that were designated A4p15 – RNA labeled with Cy3; and (ii) Transformed A4 cells at passage 84 that were designated A4p84 – RNA labeled with Cy5. Three samples of each were chosen for hybridization.