REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Mouse Anti-human Cytokeratin 7	Thermo Fisher Scientific	180234; RRID:AB_86727
Mouse Anti-human Cytokeratin 20	Agilent	M7019; RRID:AB_2133718
Mouse Cytokeratin Pan antibody Cocktail (AE1AE3)	Thermo Fisher Scientific	MA5-13203, RRID:AB_10942225
Phospho-Akt (Ser473) (D9E) XP® Rabbit mAb	Cell Signaling Technology	Cat#4060, RRID: AB_231504
Akt Antibody	Cell Signaling Technology	Cat#9272, RRID:AB_329827
Phospho-S6 Ribosomal Protein (Ser235/236) Antibody	Cell Signaling Technology	Cat#2211, RRID:AB_331679
S6 Ribosomal Protein (5G10) Rabbit mAb	Cell Signaling Technology	Cat#2217, RRID:AB_331355
Anti-β-Actin Antibody (C4)	Santa Cruz	sc-47778, RRID:AB_2714189
Anti-Rabbit IgG (H+L), HRP Conjugate	Promega	W4011
Anti-Mouse IgG (H+L), HRP Conjugate	Promega	W4021
Biological samples
35 Brain Metastases collected from patients	This study	N/A
PDX samples	This study	N/A
PDCs	This study	N/A
Chemicals, peptides, and recombinant proteins
Buparlisib (NVP-BKM120)	Selleckchem	S2247
Everolimus (RAD001)	Selleckchem	S1120
B-27™ Supplement (50X), serum free	Gibco™	17504044
DMEM/F-12	Gibco™	11320074
HEPES (1 M)	Gibco™	15630080
L-Glutamine (200 mM)	Gibco™	A2916801
rhEGF	Merck Life Science	E9644
Human Recombinant bFGF	StemCell Technologies	78003
N-2 Supplement (100X)	Gibco™	17502048
Kynurenic Acid	Sigma-Aldrich	K3375
Trypsin from porcine pancreas	Sigma-Aldrich	T4799
Deoxyribonuclease I from bovine pancreas	Sigma-Aldrich	DN25
Hyaluronidase from sheep testes	Sigma-Aldrich	H6254
Trypsin inhibitor from chicken egg white	Sigma-Aldrich	T9253
Matrigel® Matrix	Corning®	354324
Poly(ethylene glycol) average Mn 300	Sigma-Aldrich	202371-500G
Dimethyl sulfoxide (DMSO)	Sigma-Aldrich	D2650
Laminin from Engelbreth-Holm-Swarm murine sarcoma basement membrane	Sigma-Aldrich	L-2020
Poly-L-ornithine solution	Sigma-Aldrich	P4957
Accutase® solution	Sigma-Aldrich	A6964
Trizma-Base	Sigma-Aldrich	93362
Sodium Cloride (NaCl)	Sigma-Aldrich	S3014
Ethylenediaminetetraacetic acid (EDTA)	Sigma-Aldrich	E6758
Fetal Bovine Serum	Biowest	S181B-500
Euthasol: Sodium Pentobarbital 400mg/ml	Dechra	N/A
Isovet: Isoflurane 1000mg/g 250ml	B. Braun Medical	N/A
Bupaq: Buprenorphine 0,3mg/ml	Plurivet	N/A
Critical commercial assays
CellTiter 96® Aqueous One Solution Cell Proliferation Assay (MTS)	Promega	G3580
6.5 mm Transwell® with 8.0 μm Pore Polyester Membrane Insert	Corning	3464
PhosSTOP™	Roche	4906845001
cOmplete™, Mini Protease Inhibitor Cocktail	Roche	11836153001
Nitrocellulose Membrane 0.2 μm	Bio-Rad	1620112
Bio-Rad Protein Assay Dye Reagent Concentrate	Bio-Rad	5000006
Pierce™ ECL Western Blotting Substrate	ThermoFisher Scientific	32106
EnVision+/HRP, Rabbit, HRP. Rabbit	Agilent	K4003
Deposited data
RNAseq of human brain metastases	Sequence Read Archive (SRA)	BioProject: PRJNA820633
Experimental models: Cell lines
MET-CF78	This Study	N/A
MET-CF89	This Study	N/A
MET-CF70	This Study	N/A
MET-CF69	This Study	N/A
MET-CF29	This Study	N/A
MET-CF81	This Study	N/A
Experimental models: Organisms/strains
NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ	Charles River Laboratories	RRID: IMSR_JAX:005557
Software and algorithms
FIJI	Schindelin J, et al. 2012	https://fiji.sc/
GraphPad Prism version 8.0.0 for Windows	GraphPad Software	https://www.graphpad.com/
G∗Power 3.1 software	Heinrich-Heine University of Dusseldorf	http://www.gpower.hhu.de
RANDOM.ORG: True Random Number Service.	Randomness and Integrity Services Ltd.	https://www.random.org
STAR 2.7.4a	Dobin et al, 2013	https://github.com/alexdobin/STAR
HTSeq (v.0.6.1p1)	Anders et al, 2014	https://htseq.readthedocs.io/en/master/index.html
DESeq2	Love et al, 2014	https://bioconductor.org/packages/release/bioc/html/DESeq2.html
Other
Novosyn - Mid-term absorbable braided and coated suture made of polyglactin 910	Braun	G0068213
Medical X-Ray Film Blue	Agfa	CP-BU New
Corning® Primaria™ 100 mm x 20 mm Standard Cell Culture Dish	Corning	353803
Falcon™ Cell Strainers 70μm	Fisher Scientific	352350
Epredia™ Lab Vision™ PT Module	Fisher Scientific	A80400012