Human Metastatic Cholangiocarcinoma Patient-Derived Xenografts and Tumoroids for Preclinical Drug Evaluation

Human metastatic cholangiocarcinoma; Xenografts; TumoroidsColangiocarcinoma metastàtic humà; Xenoempelts; TumoroidesColangiocarcinoma metastásico humano; Xenoinjertos; TumoroidesPurpose: Cholangiocarcinoma (CCA) is usually diagnosed at advanced stages, with limited therapeutic options. Preclinical models focused on unresectable metastatic CCA are necessary to develop rational treatments. Pathogenic mutations in IDH1/2, ARID1A/B, BAP1, and BRCA1/2 have been identified in 30%–50% of patients with CCA. Several types of tumor cells harboring these mutations exhibit homologous recombination deficiency (HRD) phenotype with enhanced sensitivity to PARP inhibitors (PARPi). However, PARPi treatment has not yet been tested for effectiveness in patient-derived models of advanced CCA. Experimental Design: We have established a collection of patient-derived xenografts from patients with unresectable metastatic CCA (CCA_PDX). The CCA_PDXs were characterized at both histopathologic and genomic levels. We optimized a protocol to generate CCA tumoroids from CCA_PDXs. We tested the effects of PARPis in both CCA tumoroids and CCA_PDXs. Finally, we used the RAD51 assay to evaluate the HRD status of CCA tissues. Results: This collection of CCA_PDXs recapitulates the histopathologic and molecular features of their original tumors. PARPi treatments inhibited the growth of CCA tumoroids and CCA_PDXs with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1. In line with these findings, only CCA_PDX and CCA patient biopsy samples with mutations of BRCA2 showed RAD51 scores compatible with HRD. Conclusions: Our results suggest that patients with advanced CCA with pathogenic mutations of BRCA2, but not those with mutations of IDH1, ARID1A, or BAP1, are likely to benefit from PARPi therapy. This collection of CCA_PDXs provides new opportunities for evaluating drug response and prioritizing clinical trials.This work was supported by grants from the Fundació Marató TV3 awarded to T. Macarulla, M. Melé, and S. Peiró; BeiGene research grant awarded to T. Macarulla and S. Peiró; AECC (INVES20036TIAN), Ramón y Cajal investigator program (RYC2020-029098-I), Proyecto de I+D+i (PID2019-108008RJ-I00), and FERO Foundation grant awarded to T.V. Tian; Proyecto de Investigación en Salud from the Instituto de Salud Carlos III (ISCIII) (PI20/00898) awarded to T. Macarulla; FIS/FEDER from the Instituto de Salud Carlos III (ISCIII) (PI12/01250; CP08/00223; PI16/00253 and CB16/12/00449) awarded to S. Peiró; and Ramón y Cajal investigator program (RYC-2017-22249) awarded to M. Melé. Q. Serra-Camprubí is a recipient of the Ph.D. fellowship from La Caixa Foundation (LCF/PR/PR12/51070001). A. Llop-Guevara was supported by the AECC (INVES20095LLOP) and V. Serra by the ISCIII (CPII19/00033). E.J. Arenas was funded by the AECC (POSTD211413AREN). J. Arribas is funded by the Instituto de Salud Carlos III (AC15/00062, CB16/12/00449, and PI22/00001). This publication is based upon the work of COST Action CA18122, European Cholangiocarcinoma Network, supported by the COST (European Cooperation in Science and Technology, www.cost.eu), a funding agency for research and innovation networks. The authors would like to thank Dr. V.A. Raker for manuscript editing and Drs. N. Herranz and J. Mateo for scientific discussions. The authors acknowledge the infrastructure and support of the FERO Foundation, La Caixa Foundation, and the Cellex Foundation

LOXL2-mediated H3K4 oxidation reduces chromatin accessibility in triple-negative breast cancer cells

Cromosomes; Marcadors pronòsticsCromosomas; Marcadores de pronósticoChromosomes; Prognostic markersOxidation of H3 at lysine 4 (H3K4ox) by lysyl oxidase-like 2 (LOXL2) generates an H3 modification with an unknown physiological function. We find that LOXL2 and H3K4ox are higher in triple-negative breast cancer (TNBC) cell lines and patient-derived xenografts (PDXs) than those from other breast cancer subtypes. ChIP-seq revealed that H3K4ox is located primarily in heterochromatin, where it is involved in chromatin compaction. Knocking down LOXL2 reduces H3K4ox levels and causes chromatin decompaction, resulting in a sustained activation of the DNA damage response (DDR) and increased susceptibility to anticancer agents. This critical role that LOXL2 and oxidized H3 play in chromatin compaction and DDR suggests that functionally targeting LOXL2 could be a way to sensitize TNBC cells to conventional therapy.This work was supported by grants from Instituto de Salud Carlos III (ISCIII) FIS/FEDER (PI12/01250; CP08/00223; PI16/00253; and CB16/12/00449), MINECO (SAF2013-48849-C2-1-R) to SP, BFU2015-68354 to THS, Breast Cancer Research Foundation (BCRF-17-008) to JA, AGL2014-52395-C2-2-R to DA, Worldwide Cancer Research, Red Temática de Investigación Cooperativa en Cáncer (RD012/0036/005), Fundación Científica de la Asociación Española contra el Cáncer, and Fundació La Marató TV3. THS was supported by institutional funding (MINECO) through the Centres of Excellence Severo Ochoa award and the CERCA Programme of the Catalan Government, and SS-B, by a Fundació La Caixa fellowship. We thank La Caixa Foundation and Cellex Foundation for provide research facilities and equipment. GV has received funding from the MINECO (a “Juan de la Cierva Incorporation” fellowship; IJCI-2014-20723). SP was a recipient of a Miguel Servet contract (ISCIII/FIS), and AI, JPC-C, LP-G, and GS-B are supported by contracts from Worldwide Cancer Research, Fundació La Marató TV3, Fundació FERO, and a FI Fellowship from the Generalitat de Catalunya, respectively