Abstract 5138: New technique generates cell cultures from rare adenoid cystic carcinomas of the salivary gland
Authors: Chen Chen , Choudhury Sujata , Liu Xuefeng , Schlegel Richard , Agarwal Seema 
Published: August 2015

Introduction: Historically it has been difficult to generate and maintain cell cultures derived directly from a patient's tumor and virtually impossible to generate continuous cultures of normal cells. Preclinical models provide an essential tool to study both basic biology as well as aid in translational research, including drug target identification and drug discovery efforts. Even today, one of the greatest challenges in cancer research has been the generation of stable cancer cell lines that can genocopy and phenocopy the respective primary tumors. Recently, a new cell culture method was developed by our research group (Liu et al, AJP 2012) called “conditionally reprogrammed cells” (CRCs). Cells derived from primary tumors and corresponding normal tissues can be grown indefinitely under defined conditions without using any extrinsic genetic immortalization technique. No authentic cell culture line currently exists for the rare and aggressive adenocystic carcinoma (ACC) of the salivary gland and the few cell lines described have proven to be contaminated with conventional cell lines such as HeLa. Here we show that our CRC technology can be successfully applied to generate cell cultures from this rare subtype of salivary gland tumor.

Method: The CRC technique utilizes irradiated mouse J2 feeder cells and a ROCK inhibitor to rapidly grow and expand each patient's epithelial cells. All PDx tissue samples were provided by the Adenoid Cystic Carcinoma Research Foundation (ACCRF) and processed in our laboratory for generating CRC lines. STR analysis indicated that these cultures are unique and show no similarity to cell lines in the ATCC data base.

Results: We have successfully established CRC cultures from three different PDx tumor biopsies. Preliminary analysis on one CRC culture, ACC11, shows that the Myb-NF1B translocation is maintained, similar to the primary tumor and PDx. The sequencing of RT-PCR products using primers for Myb and NF1B revealed the exact break point for both genes. The cell cultlure maintains the overexpression of the Myb protein as assessed by Western blot when compared with a non-ACC salivery gland culture. Next generation sequencing of 48 TruSeq cancer panel identified mutations in key genes including ATM and FGFR2 that were further confirmed by RT-PCR followed by sequencing.

Conclusion: The CRC technology represents a new approach to culturing cells from tumors and normal cells, including tumors that have been historically challenging to grow such as ACC of salivary gland. The resulting cells maintained the key genetic translocation and corresponding overexpression of the Myb protein. Newly identified mutations were also discovered in this tumor. Future studies will explore the genetic alterations in the two additional ACC tumor cell cultures and to generate a biobank of ACC tumor cultures for basic biological studies and to identify the key drivers of malignancy.

Citation Format: Chen Chen, Sujata Choudhury, Xuefeng Liu, Richard Schlegel, Seema Agarwal. New technique generates cell cultures from rare adenoid cystic carcinomas of the salivary gland. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5138. doi:10.1158/1538-7445.AM2015-5138