Female swiss nude mice

Human hormone-dependent tumor samples from one patient were validated and provided by Prof. Marangoni (Institute Curie, Paris, France) for PDX experiments, as described previously [28 (link),29 (link)]. The HBCx-131 PDX model was obtained by engrafting a biopsy from spinal bone metastasis of an ER+ breast cancer patient treated with vertebroplasty as detailed in Montaudon et al. [30 (link)]. The metastasis biopsy was engrafted with the patient’s informed consent into female Swiss nude mice (Charles River Laboratories, Saint-Germain Nuelles, France) that were maintained in specific pathogen-free animal housing and received estrogen diluted in drinking water. These experiments were conducted in accordance with the guidelines of the French Ethics Committee (project authorization no. 02163.02) and in accordance with the current legislation and recommendations of the Ethical Committee of the University Hospital of Liège (project authorization no. 14-1582).

PDX models of ER+ metastatic BC were obtained by engrafting biopsies from spinal bone metastases of ER-positive BC female patients progressing under ET and treated with vertebroplasty to restore biomechanical vertebral properties (stabilisation) and reduce back pain, as described previously^{13 (link)}. The protocol was approved by the Institut Curie Hospital committee (CRI: Comité de Revue Institutionnel). Bone metastasis biopsies were engrafted with informed consent from the patient into the interscapular fat pad of 8- to 12-week-old female Swiss nude mice (Charles River Laboratories), which were maintained under specific pathogen-free conditions. Their care and housing were in accordance with institutional guidelines and the rules of the French Ethics Committee: CEEA-IC (Comité d’Ethique en matière d’expérimentation animale de l’Institut Curie, National registration number: #118). The project authorisation no. is 02163.02. The housing facility was kept at 22 °C (±2 °C) with a relative humidity of 30–70%. The light/dark cycle was 12 h light/12 h dark. Mice were maintained on a standard diet (4RF25, Mucedola SRL, Italy) and were given free access to food and water.

Female Swiss nude mice were obtained from Charles River Laboratories. Animals used in the study were uniform in age (6 weeks) and body weight (20–23 g).
Mice were injected subcutaneously (s.c.) into the right flank with 5 × 10⁶ human LoVo tumor cells. When tumors reached a diameter of 100–300 mm³, mice were assigned in a random, blinded manner to receive the recombinant RCNV. Nude mice were treated by a single intratumoral injection of RCNtk-/gfp::fcu1 vector at the dose of 1 × 10⁷ pfu (in 100 µl PBS) or vehicle (control group). Five days post injection, 5-FC was administrated by oral gavage at 100 mg/kg (0.5 ml 5-FC 0.5% in water) twice a day for 3 weeks. Tumor size was measured twice a week using calipers. Tumor volume was calculated in mm³ using the formula (Π/6) (length × width²).

5 × 10 E6 exponentially growing cells were subcutaneously injected into the interscapular fat pad of six weeks-old female Swiss nude mice (Charles Rivers Laboratories, France). Tumour growth was evaluated by measuring two perpendicular diameters of tumours with a caliper three times per week. Individual tumour volumes were calculated as V = a × b²/2, with a being the major diameter, and b the minor diameter. Tumour growth curves were established as a function of time. Mice were sacrificed once tumours reached a volume of 1500 mm³. Experiments were performed in compliance with animal welfare regulations of the European Community (86/609/EEC), the French Competent Authority, and the UKCCCR guidelines.

PDX models of ER+ metastatic BC were obtained by engrafting biopsies from spinal bone metastases of ER-positive BC patients progressing under ET and treated with vertebroplasty to restore biomechanical vertebral properties (stabilisation) and reduce back pain. The protocol was approved by the Institut Curie Hospital committee (CRI: Comité de Revue Institutionnel). Bone metastasis biopsies were engrafted with informed consent from the patient into the interscapular fat pad of female Swiss nude mice (Charles River Laboratories), which were maintained under specific pathogen-free conditions. Their care and housing were in accordance with institutional guidelines and the rules of the French Ethics Committee: CEEA-IC (Comité d’Ethique en matière d’expérimentation animale de l’Institut Curie, National registration number: #118). The project authorisation no. is 02163.02. The housing facility was kept at 22 °C (±2 °C) with a relative humidity of 30–70%. The light/dark cycle was 12 h light/12 h dark.

Female Swiss nude mice (8–10 weeks old) were obtained from Charles River Laboratories (L’Arbresle, France). The protocol was approved by the Committee on the Ethics of Animal Experiments of the “Pays de la Loire” (Permit no. 01785.01). Animals were anesthetized by an intraperitoneal injection of xylazine (13 mg/kg body weight) and ketamine (100 mg/kg body weight) and were positioned in a Kopf stereotaxic instrument. On day 0 (D0), U87MG cells (3 × 10⁴) in 5 μL HBSS with Ca²⁺ and Mg²⁺ were injected into the striatum of mice [coordinates: 2.1 mm lateral to the bregma, 0.5 mm anterior and 3 mm interior to the outer border of the cranium].

Female Swiss nude mice were purchased from Charles River Laboratories and were maintained under specific pathogen-free conditions. Their care and housing were in accordance with institutional guidelines and the rules of the French Ethics Committee (project authorization no. 02163.02). A PDX from a residual triple-negative breast cancer post neo-adjuvant chemotherapy (HBCx-95) was previously established at Institut Curie with informed consent from the patient^{1 (link)}. Prior to single-cell ChIP-seq, PDX was digested at 37 °C for 2 h with a cocktail of Collagenase I (Roche, # 11088793001) and Hyaluronidase (Sigma, # H3506). Cells were then individualized at 37 °C using a cocktail of 0.25% trypsin/Versen (ThermoFisher Scientific, #15040-033), Dispase II (Sigma, #D4693), and Dnase I (Roche, # 11284932001). Red Blood Cell lysis buffer (ThermoFisher Scientific, # 00-4333-57) was then added to degrade red blood cells. In order to increase the viability of the cell suspension, dead cells were removed using the Dead Cell Removal kit (Miltenyi Biotec). Cells were re-suspended in PBS/0.04% BSA (ThermoFisher Scientific, # AM2616).