Abstract 4267: Establishment and biological characterization of a Chilean ascites-derived gallbladder cancer cell line

Gallbladder cancer is the most common biliary tract cancer. Globally, it is considered as a rare malignancy but shows a high incidence in certain geographic areas, such as Eastern and South Asia, Eastern Europe and Latin America. In Chile, this aggressive neoplasia is the second leading cause of cancer death among women, with a mortality rate of 15 deaths per 100.000 women, only slightly lower than breast cancer. Most patients with gallbladder cancer are diagnosed at advanced stages and the prognosis still remains low, even using the most current diagnostic techniques. Tumor biology of gallbladder cancer is still poorly understood and there are no therapeutic options to improve the prognosis of patients with advanced gallbladder cancer. The establishment of cell lines for their use as in vitro models is essential for the study of tumor biology and drug susceptibility. The aim of this study was to characterize and compare the malignant properties of three gallbladder cancer clones isolated from ascites-derived primary culture cells. Tumor cells were isolated from the ascites of an advanced gallbladder cancer patient using a previously established protocol. The primary culture cells were characterized to determine their epithelial origin by using immunohistochemical markers. Due to the heterogeneous nature of these cells, individual clones were isolated from them and maintained in culture until their establishment as immortal cell lines (less than 20 passages). Finally, three clones were obtained and evaluated in order to characterize and compare their malignant properties, determining their growth rate, chemosensitivity to gemcitabine, cisplatin and 5-fluoracil, migration capability and the in vivo tumorigenesis induction. The ascites-derived primary culture cells showed high expression of epithelial and tumor markers (Cytokeratin 7 and 19, CA 19-9, CA 125, CA 15-3) and negative expression of mesothelial markers (calretinin and mesothelin). Individual clones (clone 1, 2 and 3) derived from the primary culture showed differences from each other. The calculated doubling time was 60h for Clone 1, 35h for Clone 2, and 28h for Clone 3. All three clones were equally sensible to gemcitabine, cisplatin and 5-Fluoracil, compared to other established gallbladder cancer cell lines. Clone 5 exhibited the greater migration potential and Clone 6 resulted to have the most tumorigenic capability, although all were able to form xenograft tumors before 2 weeks. Conclusions: To our knowledge, these are the first gallbladder cancer cell lines established from a Chilean patient and they may provide a useful tool for the study of gallbladder cancer biology and for in vitro and in vivo analysis aimed at identification of new potential therapeutic targets. Research supported by FONDECYT 11130515, 1151008, 1130204, 3140426 and 3140308. Citation Format: Javier Retamal, Carolina Bizama, Jaime Espinoza, Lorena Rosa, Francisca Alfaro, Diego Romero, Maria Jose Apud, Bruno Nervi, Pamela Leal, Helga Weber, Juan Carlos Roa, Patricia Garcia. Establishment and biological characterization of a Chilean ascites-derived gallbladder cancer cell line. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4267.