Development of New Cell and Animal Models to Transform Adrenocortical Cancer Research

Presentation Number: OR01-2
Date of Presentation: April 3rd, 2017

Katja Kiseljak-Vassiliades*1, Yu Zhang2, Stacey M Bagby2, Mei Xu2, Christopher D Raeburn2, Maria Albuja-Cruz2, Lauren Fishbein2, Nikita Pozdeyev3, Hilary Somerset2, Todd M Pitts2, Stephen Leong2 and Margaret E Wierman4
1University of Colorado School of Medicine and Research Service VAMC, Aurora, CO, 2University of Colorado School of Medicine, Aurora, CO, 3University of Colorado Medical School, Aurora, CO, 4University of Colorado School of Medicine and Research Service Veterans Affairs Medical Center, Denver, CO

Abstract

Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy with an estimated annual incidence of 0.7-2 cases per million and a 5-year survival of less than 35%. Surgical resection remains the only chance for a cure; however, many tumors are not resectable and most recur. Mitotane is the main therapeutic agent used to reduce recurrence, but it has significant toxicities. Chemotherapy with EDP (etoposide, doxorubicin and cisplatin) is a mainstay therapy for advanced metastatic ACC, but with a response rate of only 20% with progression free survival of five months. The scarcity of human ACC cell lines and lack of rodent models have significantly limited progress in the field. Using the xenograft strategies pioneered by our GI Oncology group, in concert with new methods of cancer cell line development, our initial goal has been to develop new in vitro and in vivo models in ACC. We report the development of a new immortalized human ACC cell line (ACC001) and four new patient-derived xenograft (PDX) ACC tumor models. ACC001 was isolated from ACC001-PDX derived from an ACC metastasis using the feeder cells/ROCK inhibitor method. The authenticity of the human ACC cell line was confirmed using short tandem repeat (STR) profiling demonstrating 100% match with the ACC001-PDX tumor and 94% match with the patient’s DNA. LC-MS/MS was performed to evaluate the hormone secretory profile of ACC001 and preliminary studies suggest that the cells secrete aldosterone, when stimulated by Angiotensin II, in addition to cortisol, deoxycorticosterone and corticosterone at baseline without further increase with ACTH stimulation. ACC001 is currently at passage 20 with a doubling time of 48-72 hrs. We also have established four adult ACC PDX models in nude mice, from three metastatic and one primary ACC. Histopathology from two of the human tumors and matched PDX tumors showed consistent architecture between matching pairs. ACC001-PDX is from an ACC perinephric metastasis in a 69 yo female’s tumor which initially secreted aldosterone with loss of hormone production in metastases. ACC002.1-PDX and ACC002.2-PDX are from separate metastatic lesions from a 23 yo female with Lynch Syndrome. ACC004-PDX is from a primary tumor resected from a 54 yo female with sporadic ACC and hypercortisolism. Next generation whole exome sequencing and RNA sequencing are underway to further characterize our newly developed models, and evaluate for possible genomic drift from the original primary tumors. In summary, we have successfully generated novel in vitro and in vivo adrenocortical cancer models, which can allow the identification and testing of new therapeutics for patients with ACC.

 

Nothing to Disclose: KK, YZ, SMB, MX, CDR, MA, LF, NP, HS, TMP, SL, MEW