Abstract KLF8 is a dual transcription factor that plays a role in oncogenic transformation in mouse fibroblast cells and is highly over-expressed in human ovarian cancer. To test if KLF8 alone or together with each of the ovarian oncoprotein c-Myc, Stat3c or Akt plays a role in ovarian cell transformation, we used the immortalized normal human ovarian epithelial cell line T80 to generate stable cell lines that overexpress KLF8 alone or its combination with one of the other three oncoproteins. The Soft agar assay showed that T80/KLF8 formed significantly more colonies compared with the mock control cells, suggesting that KLF8 may play a role to transform T80 cells. Interestingly the cells expressing both KLF8 and c-Myc formed the largest amounts of colonies that were even greater than the sum of colonies formed by the cells expressing either KLF8 or c-Myc alone, suggesting a potential synergistic role of KLF8 with c-Myc. Surprisingly, however, overexpression of KLF8 alone was sufficient to induce tumorigenesis in athymic mice when the T80/KLF8 cells were injected subcutaneously (s.c.), intraperitoneally (i.p.) or orthotopically into the ovarian bursa. HE and IHC staining identified the tumors’ epithelial origin characteristic of human ovarian cancer. The s.c. growth rate of the T80/KLF8 tumors was greater than the T80/Stat3c tumors and similar to T80/Akt tumors although slower than the tumors formed by SKOV3ip1 and T80/c-Myc cells. The average survival time for the mice with the i.p. implantations was about six months for T80/KLF8 as compared to approximately two months for SKOV3ip1. These novel findings suggest that KLF8 plays a critical oncogenic role in synergy with c-Myc in the ovarian cancer progression. The mouse tumor models generated in this work provide important tools for the studies of mechanisms underlying human ovarian cancer progression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4306. doi:10.1158/1538-7445.AM2011-4306