Impact of extracellular matrix stiffness on genomic heterogeneity in MYCN-amplified neuroblastoma cell line

Amparo López-Carrasco,Beatriz Fernández-Blanco,Ezequiel Monferrer,Samuel Navarro,Rebeca Burgos-Panadero,Rosa Noguera,Ana P Berbegall,Susana Martín-Vañó

doi:10.1186/s13046-020-01729-1

Abstract

BackgroundIncreased tissue stiffness is a common feature of malignant solid tumors, often associated with metastasis and poor patient outcomes. Vitronectin, as an extracellular matrix anchorage glycoprotein related to a stiff matrix, is present in a particularly increased quantity and specific distribution in high-risk neuroblastoma. Furthermore, as cells can sense and transform the proprieties of the extracellular matrix into chemical signals through mechanotransduction, genotypic changes related to stiffness are possible.MethodsWe applied high density SNPa and NGS techniques to in vivo and in vitro models (orthotropic xenograft vitronectin knock-out mice and 3D bioprinted hydrogels with different stiffness) using two representative neuroblastoma cell lines (the MYCN-amplified SK-N-BE(2) and the ALK-mutated SH-SY5Y), to discern how tumor genomics patterns and clonal heterogeneity of the two cell lines are affected.ResultsWe describe a remarkable subclonal selection of genomic aberrations in SK-N-BE(2) cells grown in knock-out vitronectin xenograft mice that also emerged when cultured for long times in stiff hydrogels. In particular, we detected an enlarged subclonal cell population with chromosome 9 aberrations in both models. Similar abnormalities were found in human high-risk neuroblastoma with MYCN amplification. The genomics of the SH-SY5Y cell line remained stable when cultured in both models.ConclusionsFocus on heterogeneous intratumor segmental chromosome aberrations and mutations, as a mirror image of tumor microenvironment, is a vital area of future research.

Highlights

Increased tissue stiffness is a common feature of malignant solid tumors, often associated with metastasis and poor patient outcomes
Chromosomal aberrations detected in Two dimensions (2D) cell culture Genomic profiling of trypsinized SK-N-BE(2) cells grown traditionally in monolayer culture revealed the presence of ten Segmental chromosomal aberrations (SCAs) detected by high density single nucleotide polymorphism arrays (HD-SNPa), as previously reported [42]: three SCAs typically observed in NB and seven SCAs classed as atypical for being less frequently present in NB
We have described a similar genomic response of a MYCN amplification (MNA) NB cell line grown in two different models with a niche deliberately altered in its composition and stiffness

Summary

Introduction

Increased tissue stiffness is a common feature of malignant solid tumors, often associated with metastasis and poor patient outcomes. ECM stiffness and composition are currently of such importance that, together with mechanotransduction, are considered promising therapeutic targets in many cancer types [14,15,16]. This is the case of neuroblastoma (NB), a peripheral sympathetic tumor that causes 15% of childhood deaths from cancer [17]. NB stiff ECM is rich in cross-linked collagen III fibers, poor in glycosaminoglycans, supporting sinusoidal vascular structures (blood and lymphatic) and with a high quantity of territorial vitronectin (VN, located in the cytoplasmic compartment and in a thin layer around the tumor cells) [19,20,21,22]. In this study we sought to resolve the particular question of whether host lack of VN has any impact on tumor genomics

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