To establish primary cell lines from uterine carcinosarcoma (CS) patient samples and to evaluate combination treatment with standard chemotherapy with or without the addition of an anti-IGF1R antibody.

CS tumor tissue was obtained under IRB approval at the time of primary surgery. We reported the establishment of patient-derived xenografts elsewhere. Tissue pieces were minced extensively and digested by collagenase treatment. The single cell solution was then seeded in F-media containing EGF, insulin, hydrocortisone, adenine, cholera toxin and the Rock inhibitor Y-27632. A previously established carcinosarcoma cell line CS99 (Schulten et al, 2008) was used for comparison. To verify origin, Short Tandem Repeat (STR) profiles of the primary cell lines CS13, CS18, CS19, CS21 and CS22 were compared with the patient's tumor samples. Drug sensitivity to Taxol, cisplatin and carboplatin was determined individually or in combination using the sulforhodamine B (SRB) proliferation assay. The effect of IMC-A12 (anti-IGF1R antibody, Eli Lily / Imclone) alone or with chemotherapy was also determined with the SRB assay. Total and promoter-specific IGF2 mRNA levels were determined by reverse transcriptase quantitative PCR.

All STR profiles of the primary cell lines matched their patient sample counterparts. IGF2 mRNA expression levels of the cell lines were similar to the patient samples, and over 10,000-fold higher than in CS99. IGF2 promoter-specific primers showed that the IGF2 mRNA transcripts of the primary cell lines were initiated at the oncofetal IGF2 promoters P3 and P4. For Taxol, the IC50 (inhibitory concentration of 50%) ranged from 4.7 nM for CS21 to 9.8 nM for CS22. For cisplatin, the IC50 ranged from 1.0 μM for CS99 to 4.8 μM for CS19. For carboplatin, CS99 cells had the lowest IC50 of 12.5 μM while CS19 had the highest IC50 of 58.1 μM. In the presence of 10 μg/ml IMC-A12, the primary cell lines CS19, CS21 and CS22 showed significant sensitization to Taxol (∼50% decrease in IC50), to carboplatin (∼65% decrease in IC50), and to combination Taxol/carboplatin treatment (∼50% decrease in IC50).

We conclude that establishing primary cell lines of this rare cancer is a promising approach for testing sensitivity to current and novel chemotherapies and combination treatment strategies. We also found that high oncofetal promoter-driven IGF2 mRNA expression was observed in all CS samples tested and that IGF1R blockade sensitized the primary cell lines to standard chemotherapy.

Citation Format: Jurriaan Brouwer-Visser, Eirwen Scott, Shijun Mi, Maria J. Cossio, Tiffany Hebert, Gloria S. Huang. Establishment of uterine carcinosarcoma primary cell lines for chemosensitivity testing and evaluation of targeted therapy. [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 5131. doi:10.1158/1538-7445.AM2015-5131