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Valeria Laufs, Barbara Altieri, Silviu Sbiera, Stefan Kircher, Sonja Steinhauer, Felix Beuschlein, Marcus Quinkler, Holger S Willenberg, Andreas Rosenwald, Martin Fassnacht, and Cristina L Ronchi

Objective

Platinum-based chemotherapy (PBC) is the most effective cytotoxic treatment for advanced adrenocortical carcinoma (ACC). Excision repair cross complementing group 1 (ERCC1) plays a critical role in the repair of platinum-induced DNA damage. Two studies investigating the role of ERCC1 immunostaining as a predictive marker for the response to PBC in ACC had reported conflicting results. Both studies used the ERCC1-antibody clone 8F1 that later turned out to be not specific. The aim of this study was to evaluate the predictive role of ERCC1 with a new specific antibody in a larger series of ACC.

Design and methods

146 ACC patients with available FFPE slides were investigated. All patients underwent PBC (median cycles = 6), including cisplatin (n = 131) or carboplatin (n = 15), in most cases combined with etoposide (n = 144), doxorubicin (n = 131) and mitotane (n = 131). Immunostaining was performed with the novel ERCC1-antibody clone 4F9. The relationship between ERCC1 expression and clinicopathological parameters, as well as best objective response to therapy and progression-free survival (PFS) during PBC was evaluated.

Results

High ERCC1 expression was observed in 66% of ACC samples. During PBC, 43 patients experienced objective response (29.5%), 49 stable disease (33.6%), 8 mixed response (5.5%) and 46 progressive disease (31.5%) without any relationship with the ERCC1 immunostaining. No significant correlation was also found between ERCC1 expression and progression-free survival (median 6.5 vs 6 months, P=0.33, HR = 1.23, 95% CI = 0.82–2.0).

Conclusion

ERCC1 expression is not directly associated with sensitivity to PBC in ACC. Thus, other predictive biomarkers are required to support treatment decisions in patients with ACC.

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Laura-Sophie Landwehr, Jochen Schreiner, Silke Appenzeller, Stefan Kircher, Sabine Herterich, Silviu Sbiera, Martin Fassnacht, Matthias Kroiss, and Isabel Weigand

Background

The response of advanced adrenocortical carcinoma (ACC) to current chemotherapies is unsatisfactory and a limited rate of response to immunotherapy was observed in clinical trials. High tumour mutational burden (TMB) and the presence of a specific DNA signature are characteristic features of tumours with mutations in the gene MUTYH encoding the mutY DNA glycosylase. Both have been shown to potentially predict the response to immunotherapy. High TMB in an ACC cell line model has not been reported yet.

Design and methods

The JIL-2266 cell line was established from a primary ACC tumour, comprehensively characterised and oxidative damage, caused by a dysfunctional mutY DNA glycosylase, confirmed.

Results

Here, we characterise the novel patient-derived ACC cell line JIL-2266, which is deficient in mutY-dependent DNA repair. JIL-2266 cells have a consistent STR marker profile that confirmed congruousness with primary ACC tumour. Cells proliferate with a doubling time of 41 ± 13 h. Immunohistochemistry revealed positivity for steroidogenic factor-1. Mass spectrometry did not demonstrate significant steroid hormone synthesis. JIL-2266 have hemizygous mutations in the tumour suppressor gene TP53 (c.859G>T:p.E287X) and MUTYH (c.316C>T:p.R106W). Exome sequencing showed 683 single nucleotide variants and 4 insertions/deletions. We found increased oxidative DNA damage in the cell line and the corresponding primary tumour caused by impaired mutY DNA glycosylase function and accumulation of 8-oxoguanine.

Conclusion

This model will be valuable as a pre-clinical ACC cell model with high TMB and a tool to study oxidative DNA damage in the adrenal gland.

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Masanori Murakami, Na Sun, Christian Greunke, Annette Feuchtinger, Stefan Kircher, Timo Deutschbein, Thomas Papathomas, Nicole Bechmann, Paal William Wallace, Mirko Peitzsch, Esther Korpershoek, Juliane Friemel, Anne Paule Gimenez Roqueplo, Mercedes Robledo, Henri Jlm Timmers, Letizia Canu, Achim Weber, Ronald R de Krijger, Martin Fassnacht, Thomas Knösel, Thomas Kirchner, Martin Reincke, Axel Karl Walch, Matthias Kroiss, and Felix Beuschlein

Objective: Within the past decade, important genetic drivers of pheochromocytoma and paraganglioma (PPGLs) development have been identified. The pathophysiological mechanism that translate these alterations into functional autonomy and potentially malignant behavior have not been elucidated in detail. Here we used MALDI-mass spectrometry imaging (MALDI-MSI) of formalin-fixed paraffin-embedded tissue specimens to comprehensively characterize the metabolic profiles of PPGLs.

Design and methods: MALDI-MSI was conducted in 344 PPGLs and results correlated with genetic and phenotypic information. We experimentally silenced genetic drivers by siRNA in PC12 cells to confirm their metabolic impact in vitro.

Results: Tissue abundance of kynurenine pathway metabolites such as xanthurenic acid was significantly lower (P = 5.06E-11) in the pseudohypoxia pathway cluster 1 compared to PPGLs of the kinase-driven PPGLs cluster 2. Lower abundance of xanthurenic acid was associated with shorter metastasis-free survival (log-rank tests P = 7.96E-06) and identified as a risk factor for metastasis independent of the genetic status (hazard ratio, 32.6, P = 0.002). Knock-down of Sdhb and Vhl in an in vitro model demonstrated that inositol metabolism and sialic acids were similarly modulated as in tumors of the respective cluster.

Conclusions: The present study has identified distinct tissue metabolomic profiles of PPGLs in relation to tumor genotypes. In addition, we revealed significantly altered metabolites in the kynurenine pathway in metastatic PPGLs, which can aid in the prediction of its malignant potential. However, further validation studies will be required to confirm our findings.