Using Microarrays to Interrogate Microenvironmental Impact on Cellular Phenotypes in Cancer

Summary

The purpose of the method presented here is to show how microenvironment microarrays (MEMA) can be fabricated and used to interrogate the impact of thousands of simple combinatorial microenvironments on the phenotype of cultured cells.

Abstract

Understanding the impact of the microenvironment on the phenotype of cells is a difficult problem due to the complex mixture of both soluble growth factors and matrix-associated proteins in the microenvironment in vivo. Furthermore, readily available reagents for the modeling of microenvironments in vitro typically utilize complex mixtures of proteins that are incompletely defined and suffer from batch to batch variability. The microenvironment microarray (MEMA) platform allows for the assessment of thousands of simple combinations of microenvironment proteins for their impact on cellular phenotypes in a single assay. The MEMAs are prepared in well plates, which allows the addition of individual ligands to separate wells containing arrayed extracellular matrix (ECM) proteins. The combination of the soluble ligand with each printed ECM forms a unique combination. A typical MEMA assay contains greater than 2,500 unique combinatorial microenvironments that cells are exposed to in a single assay. As a test case, the breast cancer cell line MCF7 was plated on the MEMA platform. Analysis of this assay identified factors that both enhance and inhibit the growth and proliferation of these cells. The MEMA platform is highly flexible and can be extended for use with other biological questions beyond cancer research.

Introduction

Culturing of cancer cell lines on plastic in two-dimensional (2D) monolayers remains one of the major workhorses for cancer researchers. However, the microenvironment is increasingly being recognized for its ability to impact cellular phenotypes. In cancer, the tumor microenvironment is known to influence multiple cellular behaviors, including growth, survival, invasion, and response to therapy^1,2. Traditional monolayer cell cultures typically lack microenvironment influences, which has led to the development of more complex three-dimensional (3D) assays to grow cells, including commercially available purified....

Protocol

NOTE: An overview of the entire MEMA process, including estimated time, is outlined in the flow diagram shown in Figure 1. This protocol details the fabrication of MEMAs in 8-well plates. The protocol may be adapted for other plates or slides.

1. Preparation of Protein, Diluent, and Staining Buffers

1. Equilibrate vials of ECMs, ligands, and cytokines to room temperature (RT) and briefly centrifuge. Add the appropriate volume of the appropriate RT buffer as indicated on the product data sheet. Follow manufacturer’s recommendation for stock concentrations.
   NOTE:

Results

To simplify microenvironmental impacts on cell growth and proliferation and to identify conditions that promoted or inhibited cell growth and proliferation, the breast cancer cell line MCF7 was seeded on a set of eight 8-well MEMAs as described in the protocol. This assay exposed the cells to 48 different ECMs and 57 different ligands, for a total of 2736 combinatorial microenvironmental conditions. After 71 h in culture, cells were pulsed with EdU, fixed, permeablized, and stained with DAPI, the reaction for EdU detecti.......

Discussion

The importance of "dimensionality" and context has been a motivating factor in the development of in vitro culture systems as tools in the characterization of cancer cells through their interaction with the microenvironment¹¹, and the ability of in vitro culture systems to mimic the in vivo environment is a driving force behind the quest to improve those culture systems. In vitro systems, however, remain significant tools of cancer research precisely because of their ability to distil.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Aushon 2470	Aushon BioSystems		Arrayer robot system used in the protocol
Nikon HCA	Nikon		High Content Imaging system designed around Nikon Eclipse Ti Inverted Microscope
BioTek Precision XS liquid Handler	BioTek		liquid handling robot used in the protocol
Trizma hydrochloride buffer solution	Sigma	T2069
EDTA	Invitrogen	15575-038
Glycerol	Sigma	G5516
Triton X100	Sigma	T9284
Tween 20	Sigma	P7949
Kolliphor P338	BASF	50424591
384-well microarray plate, cylindrical well	Thermo Fisher	ab1055
Nunc 8 well dish	Thermo Fisher	267062
Paraformaldehyde 16% solution	Electron Microscopy Science	15710
BSA	Fisher	BP-1600
Sodium Azide	Sigma	S2002
Cell Mask	Molecular Probes	H32713
Click-iTEdU Alexa Fluor	Molecular Probes	C10357
DAPI	Promo Kine	PK-CA70740043
ALCAM	R & D Systems	656-AL	ECM
Cadherin-20 (CDH20)	R & D Systems	5604-CA	ECM
Cadherin-6 (CDH6)	R & D Systems	2715-CA	ECM
Cadherin-8 (CDH8)	R & D Systems	188-C8	ECM
CD44	R & D Systems	3660-CD	ECM
CEACAM6	R & D Systems	3934-CM	ECM
Collagen I	Cultrex	3442-050-01	ECM
Collagen Type II	Millipore	CC052	ECM
Collagen Type III	Millipore	CC054	ECM
Collagen Type IV	Sigma	C5533	ECM
Collagen Type V	Millipore	CC077	ECM
COL23A1	R & D Systems	4165-CL	ECM
Desmoglein 2	R & D Systems	947-DM	ECM
E-cadherin (CDH1)	R & D Systems	648-EC	ECM
ECM1	R & D Systems	3937-EC	ECM
Fibronectin	R & D Systems	1918-FN	ECM
GAP43	Abcam	ab114188	ECM
HyA-500K	R & D Systems	GLR002	ECM
HyA-50K	R & D Systems	GLR001	ECM
ICAM-1	R & D Systems	720-IC	ECM
Laminin	Sigma	L6274	ECM
Laminin-5	Abcam	ab42326	ECM
Lumican	R & D Systems	2846-LU	ECM
M-Cad (CDH15)	R & D Systems	4096-MC	ECM
Nidogen-1	R & D Systems	2570-ND	ECM
Osteoadherin/OSAD	R & D Systems	2884-AD	ECM
Osteopontin (SPP)	R & D Systems	1433-OP	ECM
P-Cadherin (CDH3)	R & D Systems	861-PC	ECM
PECAM1	R & D Systems	ADP6	ECM
Tenascin C	R & D Systems	3358-TC	ECM
VCAM1	R & D Systems	ADP5	ECM
Vitronectin	R & D Systems	2308-VN	ECM
Biglycan	R & D Systems	2667-CM	ECM
Decorin	R & D Systems	143-DE	ECM
Periostin	R & D Systems	3548-F2	ECM
SPARC/osteonectin	R & D Systems	941-SP	ECM
Thrombospondin-1/2	R & D Systems	3074-TH	ECM
Brevican	R & D Systems	4009-BC	ECM
Elastin	BioMatrix	5052	ECM
Fibrillin	Lynn Sakai Lab OHSU	N/A	ECM
ANGPT2	RnD_Systems_Own	623-AN-025	Ligand
IL1B	RnD_Systems_Own	201-LB-005	Ligand
CXCL8	RnD_Systems_Own	208-IL-010	Ligand
IGF1	RnD_Systems_Own	291-G1-200	Ligand
TNFRSF11B	RnD_Systems_Own	185-OS	Ligand
BMP6	RnD_Systems_Own	507-BP-020	Ligand
FLT3LG	RnD_Systems_Own	308-FK-005	Ligand
CXCL1	RnD_Systems_Own	275-GR-010	Ligand
DLL4	RnD_Systems_Own	1506-D4-050	Ligand
HGF	RnD_Systems_Own	294-HGN-005	Ligand
Wnt5a	RnD_Systems_Own	645-WN-010	Ligand
CTGF	Life_Technologies_Own	PHG0286	Ligand
LEP	RnD_Systems_Own	398-LP-01M	Ligand
FGF2	Sigma_Aldrich_Own	SRP4037-50UG	Ligand
FGF6	RnD_Systems_Own	238-F6	Ligand
IL7	RnD_Systems_Own	207-IL-005	Ligand
TGFB1	RnD_Systems_Own	246-LP-025	Ligand
PDGFB	RnD_Systems_Own	220-BB-010	Ligand
WNT10A	Genemed_Own	90009	Ligand
PTN	RnD_Systems_Own	252-PL-050	Ligand
BMP3	RnD_Systems_Own	113-BP-100	Ligand
BMP4	RnD_Systems_Own	314-BP-010	Ligand
TNFSF11	RnD_Systems_Own	390-TN-010	Ligand
CSF2	RnD_Systems_Own	215-GM-010	Ligand
BMP5	RnD_Systems_Own	615-BMC-020	Ligand
DLL1	RnD_Systems_Own	1818-DL-050	Ligand
NRG1	RnD_Systems_Own	296-HR-050	Ligand
KNG1	RnD_Systems_Own	1569-PI-010	Ligand
GPNMB	RnD_Systems_Own	2550-AC-050	Ligand
CXCL12	RnD_Systems_Own	350-NS-010	Ligand
IL15	RnD_Systems_Own	247-ILB-005	Ligand
TNF	RnD_Systems_Own	210-TA-020	Ligand
IGFBP3	RnD_Systems_Own	675-B3-025	Ligand
WNT3A	RnD_Systems_Own	5036-WNP-010	Ligand
PDGFAB	RnD_Systems_Own	222-AB	Ligand
AREG	RnD_Systems_Own	262-AR-100	Ligand
JAG1	RnD_Systems_Own	1277-JG-050	Ligand
BMP7	RnD_Systems_Own	354-BP-010	Ligand
TGFB2	RnD_Systems_Own	302-B2-010	Ligand
VEGFA	RnD_Systems_Own	293-VE-010	Ligand
IL6	RnD_Systems_Own	206-IL-010	Ligand
CXCL12	RnD_Systems_Own	351-FS-010	Ligand
NRG1	RnD_Systems_Own	378-SM	Ligand
IGFBP2	RnD_Systems_Own	674-B2-025	Ligand
SHH	RnD_Systems_Own	1314-SH-025	Ligand
FASLG	RnD_Systems_Own	126-FL-010	Ligand