Genetic stability of bone marrow-derived human mesenchymal stromal cells in the Quantum System

Abstract

Background aims The Quantum® Cell Expansion System (Quantum; Terumo BCT, Inc, Lakewood, CO, USA) is a novel hollow fiber-based device that automates and closes the cell culture process, reducing labor intensive tasks such as manual cell culture feeding and harvesting. The manual cell selection and expansion processes for the production of clinical-scale quantities of bone marrow-derived human mesenchymal stromal cells (BM-hMSCs) have been successfully translated onto the Quantum platform previously. The formerly static, manual, in vitro process performed primarily on tissue culture polystyrene substrates may raise the question of whether BM-hMSCs cultured on a hollow fiber platform yields comparable cell quality. Methods A rigorous battery of assays was used to determine the genetic stability of BM-hMSCs selected and produced with the Quantum. In this study, genetic stability was determined by assessing spectral karyotype, micronucleus formation and tumorigenicity to resolve chromosomal aberrations in the stem cell population. Cell phenotype, adherent growth kinetics and tri-lineage differentiation were also evaluated. HMSC bone marrow aspirates, obtained from three approved donors, were expanded in parallel using T225 culture flasks and the Quantum. Results BM-hMSCs harvested from the Quantum demonstrated immunophenotype, morphology and tri-lineage differentiation capacity characteristics consistent with the International Society of Cell Therapy standard for hMSCs. Cell populations showed no malignant neoplastic formation in athymic mice 60 days post-transplant, no clonal chromosomal aberrations were observed and no DNA damage was found as measured by micronucleus formation. Conclusions Quantum-produced BM-hMSCs are of comparable quality and demonstrate analogous genetic stability to BM-hMSCs cultured on tissue culture polystyrene substrates.

Large-Scale Clinical Expansion of Mesenchymal Stem Cells in the GMP-Compliant, Closed Automated Quantum® Cell Expansion System: Comparison with Expansion in Traditional T-Flasks

“…Immunosuppressive properties and differentiation into fat, bone and cartilage were also similar. Cytogenetic analyses were normal, in agreement with the recently published study of Jones et al [28].…”

Immunosuppressive capabilities of mesenchymal stromal cells are maintained under hypoxic growth conditions and after gamma irradiation

“…Although genetic instability of flask-and Quantum bioreactor-expanded MSCs and transformation of or teratoma formation by human MSCs have not been observed so far [16,18,[49][50][51], the development of MSC-derived malignancies or ectopic tissue is a rational concern regarding their transplantation into humans.…”

Human diploid MRC-5 cells exhibit several critical properties of human umbilical cord-derived mesenchymal stem cells

“…MSCs can certainly meet all these requirements as they are non-tumorigenic and retains normal diploid karyotype during long culturing [28,29]. The extremely low hTERT activity in both MRC-5 and hUC-MSC further ensures that tumorigenicity should not be a safety concern for MSCs.…”