Disulfiram Overcomes Cisplatin Resistance in Human Embryonal Carcinoma Cells

Abstract

Cisplatin resistance in testicular germ cell tumors (TGCTs) is a clinical challenge. We investigated the underlying mechanisms associated with cancer stem cell (CSC) markers and modalities circumventing the chemoresistance. Chemoresistant models (designated as CisR) of human embryonal carcinoma cell lines NTERA-2 and NCCIT were derived and characterized using flow cytometry, gene expression, functional and protein arrays. Tumorigenicity was determined on immunodeficient mouse model. Disulfiram was used to examine chemosensitization of resistant cells. ALDH1A3 isoform expression was evaluated by immunohistochemistry in 216 patients’ tissue samples. Chemoresistant cells were significantly more resistant to cisplatin, carboplatin and oxaliplatin compared to parental cells. NTERA-2 CisR cells exhibited altered morphology and increased tumorigenicity. High ALDH1A3 expression and increased ALDH activity were detected in both refractory cell lines. Disulfiram in combination with cisplatin showed synergy for NTERA-2 CisR and NCCIT CisR cells and inhibited growth of NTERA-2 CisR xenografts. Significantly higher ALDH1A3 expression was detected in TGCTs patients’ tissue samples compared to normal testicular tissue. We characterized novel clinically relevant model of chemoresistant TGCTs, for the first time identified the ALDH1A3 as a therapeutic target in TGCTs and more importantly, showed that disulfiram represents a viable treatment option for refractory TGCTs.

Testicular cancer: Determinants of cisplatin sensitivity and novel therapeutic opportunities

“…Treatment with the ALDH inhibitor disulfiram sensitized TC cells to cisplatin treatment in vitro and in vivo. In addition, a significantly higher expression of the ALDH isoform ALDH1A3 was detected in TC tumors compared to healthy testicular tissue [122]. Based on these data, a phase II clinical trial will commence and evaluate the potential of disulfiram in combination with cisplatin in relapsed or refractory TC patients (NCT03950830, currently recruiting).…”

The revival of dithiocarbamates: from pesticides to innovative medical treatments

“…High ALDH levels have been observed in many cancer stem cells ( Viola-Rhenals et al., 2018 ), including multiple relapsed germ cell tumors ( Schmidtova et al., 2019 ) and metastatic pancreatic cancer cells ( Kim et al., 2013 ). Accordingly, phase II clinical study patients are being recruited to investigate the objective response rate and patient survival when treated with DSF and cisplatin against multiple relapsed germ cell tumors ( NCT03950830 ).…”

Cisplatin Resistance in Testicular Germ Cell Tumors: Current Challenges from Various Perspectives

“…Importantly, dimethyl sulfoxide (DMSO), commonly used as a drug vehicle, was demonstrated to induce cisplatin resistance and differentiation in embryonal carcinoma cells, which should be taken into consideration when designing biological studies [ 39 ]. Moreover, in vivo mouse models of resistant disease can also be used by implanting cisplatin-resistant human tumor specimens or, more commonly, by injecting the resistant clones of (T)GCT cell lines available [ 40 , 41 , 42 ].…”

“…Novel drugs are currently being explored as either alternatives or combination partners of cisplatin, some of them already being tested in clinical settings [ 42 , 194 , 195 ]. Follow-up studies on previous data can be envisioned, since novel therapeutic agents are becoming available; for instance, telomerase activity has been suggested to also relate to cisplatin efficacy (although data is controversial) and telomerase or CDK inhibitors could be explored [ 196 , 197 , 198 ].…”