Transformation of Fallopian Tube Epithelial Cells Leads to High-Grade Tumor Formation in a Xenograft Mouse Model.
Alison M Karst, Keren Levanon, Michelle S Hirsch, Ronny Drapkin. Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA; Sheba Cancer Research Center, Chaim Sheba Medical Center, Ramat Gan, Israel; Brigham and Women's Hospital, Ramat Gan, Israel
Background: High-grade serous ovarian carcinoma (HGSOC) is the most lethal gynecological malignancy in the United States. In order to develop effective screening modalities and novel therapeutic approaches, we must better understand its pathogenesis. Recent studies have implicated the fallopian tube secretory epithelial cell (FTSEC) as a cell-of-origin for HGSOC. However, despite compelling descriptive studies, FTSEC transformation has not been demonstrated experimentally. There is an urgent need to develop a model by which FTSEC transformation can be studied in the lab. Here, we present a proof-of-principle experiment demonstrating that FTSECs can be transformed in vitro, producing cells that are highly tumorigenic in vivo.
Design: Primary human FTSECs were isolated from fallopian tube fimbriae and immortalized via transduction with retroviral vectors encoding human Telomerase Reverse Transcriptase (hTERT) and Simian Virus 40 T Antigens (SV40 TAg). Immortalized FTSECs were then transformed by introducing either H-Ras G12V or c-Myc oncogenes. Transformation was assessed in vitro by measuring cell proliferation, colony formation, and anchorage-independent growth. Tumorigenicity was assessed by xenograft into immunocompromised mice. Tumors were analyzed histologically and by immunohistochemistry.
Results: Both Ras- and Myc-transformed FTSECs exhibited increased proliferation, colony formation, and anchorage-independent growth ability in vitro compared to immortalized parental FTSECs. Moreover, both Ras-transformed and Myc-transformed FTSECs formed high-grade tumors when xenografted into immunocompromised mice, with latency periods of approximately 2 months and 4 months, respectively. The resulting tumors were histologically and immunophenotypically consistent with high-grade serous ovarian carcinoma.
Conclusions: Our results show that FTSECs can indeed be transformed into high-grade serous carcinomas. This is significant because: 1) it provides a working model that can be used to query the impact of specific genetic alterations, either alone or in combination, on normal primary FTSECs, and 2) it provides a framework for testing the transformative effects of candidate oncogenes on FTSEC growth, enabling us to identify the alterations that are most critical for driving serous tumorignesis in the fallopian tube epithelium.
Category: Gynecologic & Obstetrics
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 136, Wednesday Morning