In Vivo Tumorigenesis Was Observed after Injection of In Vitro Expanded Neural Crest Stem Cells Isolated from Adult Bone Marrow

Abstract

Bone marrow stromal cells are adult multipotent cells that represent an attractive tool in cellular therapy strategies. Several studies have reported that in vitro passaging of mesenchymal stem cells alters the functional and biological properties of those cells, leading to the accumulation of genetic aberrations. Recent studies described bone marrow stromal cells (BMSC) as mixed populations of cells including mesenchymal (MSC) and neural crest stem cells (NCSC). Here, we report the transformation of NCSC into tumorigenic cells, after in vitro long-term passaging. Indeed, the characterization of 6 neural crest-derived clones revealed the presence of one tumorigenic clone. Transcriptomic analyses of this clone highlighted, among others, numerous cell cycle checkpoint modifications and chromosome 11q down-regulation (suggesting a deletion of chromosome 11q) compared with the other clones. Moreover, unsupervised analysis such as a dendrogram generated after agglomerative hierarchical clustering comparing several transcriptomic data showed important similarities between the tumorigenic neural crest-derived clone and mammary tumor cell lines. Altogether, it appeared that NCSC isolated from adult bone marrow represents a potential danger for cellular therapy, and consequently, we recommend that phenotypic, functional and genetic assays should be performed on bone marrow mesenchymal and neural crest stem cells before in vivo use, to demonstrate whether their biological properties, after ex vivo expansion, remain suitable for clinical application.

Characterization of mesenchymal progenitor cell populations from non‐epithelial oral mucosa

“…Stress‐tolerant cell clusters of isolated skin fibroblasts or bone marrow stromal cells can differentiate into non‐tumorigenic endodermal, ectodermal, and mesodermal cells in vivo (Kuroda et al , ). Although mesenchymal stem cells are generally considered to be non‐tumorigenic, bone marrow stromal cells comprise a mixed population that includes neural crest stem cells and has potential tumorigenicity after long‐term in vitro passage (Wislet‐Gendebien et al , ). Recent studies have also reported that a human oral mucosa stem cell population expressing neural crest stem cell markers formed ectodermal‐ and mesodermal‐derived mixed tumors in severe combined immune deficiency mice (Marynka‐Kalmani et al , ).…”

Cytokinesis-Block Micronucleus Assay Adapted for Analyzing Genomic Instability of Human Mesenchymal Stem Cells

“…This procedure, necessary for the clinical application of hMSCs, is associated to the potential risk of cell immunogenicity, with issues of biosecurity regarding components of the culture medium and FBS, as well as the possibility of in vitro transformation of hMSCs [7]. High susceptibility to malignant transformation of MSCs has been described in animal models using stem cells isolated from the bone marrow of mice and monkeys, some becoming highly tumorigenic after in vitro culture, since they caused tumors in mice at sites where these cells were infused [91][92][93][94][95][96][97][98]. A recent study reported that differentiated hMSCs isolated from human bone marrow became tumorigenic in diabetic mice.…”

Tumor Formation of Adult Stem Cell Transplants in Rodent Arthritic Joints

“…Current literature is lacking for in vivo neoplastic differentiation of proven non-neoplastic MSC/ADSC, but Wislet-Gendebien et al retrospectively noted that one of the clones of the neural crest stem cells derived from bone marrow aspiration resulted in tumorigenesis in vivo after long-term in vitro passaging [47]. This specific clone surprisingly had the highest ability to differentiate into neuronal cells ( in vitro ), and also showed a very high rate of proliferation after injection into mice striatum, when compared to the other clones.…”