Identification of molecular pathways involved in oxaliplatin-associated sinusoidal dilatation Julie Agostini 1 , Stéphane Benoist 1,2 , Marie Seman 1 , Catherine Julié 3 , Sandrine Imbeaud 4 , Franck Letourneur 5 , Nicolas Cagnard 5 , Philippe Rougier 1 , Antoine Brouquet 2 , Jessica Zucman-Rossi 4 , Pierre Laurent-Puig 1,⇑ 1 Paris Descartes University, Paris Sorbonne Cité, INSERM UMR-S775, Paris, France; 2 Assistance-Publique-Hôpitaux de Paris, Hôpital Ambroise Paré, Department of Surgery, Boulogne, France; 3 Assistance-Publique-Hôpitaux de Paris, Hôpital Ambroise Paré, Department of Pathology, Boulogne, France; 4 Paris Descartes University, Paris Sorbonne Cité, INSERM UMR-S674, Paris, France; 5 Institut Cochin, INSERM U1016, Paris, France Background & Aims: Oxaliplatin-based chemotherapy for colo- rectal liver metastases (CRLM) can result in vascular liver lesions such as sinusoidal dilatations. Physiopathology remains unclear and variability between patients suggests that there is individual susceptibility. A better understanding of the molecular mecha- nisms of oxaliplatin liver toxicity may allow the identification of biomarkers and adaptation of chemotherapy delivery. Methods: Between 1998 and 2009, 83 non-tumor frozen liver samples were obtained from patients operated on for CRLM after an exclusive oxaliplatin-based chemotherapy. Gene-expression profiles were first analyzed by microarray on a selected popula- tion of 19 patients: 9 patients with severe sinusoidal dilatation after a short period of chemotherapy and 10 patients without any sinusoidal dilatation after a long period of chemotherapy. These were compared with a control group of 5 patients without any chemotherapy and lesions. Twenty-two differentially- expressed (at least 1.5-fold difference in expression) genes were selected. These were validated using microfluidic quantitative RT-PCR in an independent set of 58 patients (28 with sinusoidal dilatation and 30 without sinusoidal dilatation). Results: Among the 22 selected genes, 12 were validated as being up-regulated in samples from patients with sinusoidal dilatation compared to patients without sinusoidal dilatation. Genes involved in angiogenesis (VEGFD, THY-1, GPNMB) and cellular adhesion (VWF, CDH13, THBS2), and extracellular matrix compo- nents (COL1A1, COL4A1, SLCO1A2) were over-represented in patients with sinusoidal dilatation. Conclusions: This molecular signature confirms the involvement of angiogenesis and coagulation in sinusoidal injuries induced by oxaliplatin and reinforces a potential protective role of bev- acizumab and aspirin, as suggested in retrospective clinical studies. Ó 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved. Introduction Most patients treated for colorectal liver metastases receive a pre- operative chemotherapy as it improves resectability rate in patients with initially non resectable metastases and progres- sion-free survival in patients with resectable metastases [1–4]. The most commonly used chemotherapy regimen is oxaliplatin- based chemotherapy [1]. Rubbia-Brandt et al. showed that this reg- imen could result in vascular liver injuries such as sinusoidal obstructive syndrome [5]. Since this report, many studies con- firmed the existence of this syndrome with a prevalence ranging from 40% to 60% [6,7], and showed that it could increase the risk of bleeding and impair post-operative outcomes [5–10]. The molecular drivers of oxaliplatin liver injuries are currently unknown. A better understanding of these could help to indentify biological predictive factors, adapt chemotherapy delivery to patients at risk of sinusoidal dilatation, or prevent the occurrence of liver lesions through specific drugs. Indeed, retrospective clini- cal studies have reported that bevacizumab chemotherapy or aspi- rin intake protected against the development of sinusoidal obstructive syndrome [11–14]. Although some studies showed that vascular injuries increase with cumulative doses of oxalipla- tin, some patients develop severe sinusoidal dilatations even after a very short period of treatment whereas others do not develop any lesions after a long period of treatment [11,15]. This suggests that there is an individual susceptibility to oxaliplatin liver toxicity [6,7,11]. To identify the mechanisms of oxaliplatin-associated sinusoidal dilatation, we took advantage of the great variability in the occurrence of oxaliplatin liver toxic effects and we compared liver gene expression between patients without any lesions while taking higher cumulative doses of oxaliplatin and patients with lesions while taking lower cumulative doses of oxaliplatin. We showed that angiogenesis, cellular adhesion, and extracel- lular matrix components are all strongly involved in the develop- ment of oxaliplatin-induced sinusoidal injuries. Journal of Hepatology 2012 vol. 56 j 869–876 Keywords: Sinusoidal dilatation; Oxaliplatin; Colorectal liver metastases; Molecular pathways. Received 7 July 2011; received in revised form 4 October 2011; accepted 19 October 2011; available online 24 December 2011 ⇑ Corresponding author. Address: UMR-S INSERM 775, Paris Descartes Univer- sity, 45 rue des Saints-Pères, 75006 Paris, France. Tel.: +33 1 42 86 20 81; fax: +33 1 42 86 20 72. E-mail address: pierre.laurent-puig@parisdescartes.fr (P. Laurent-Puig). Research Article