Human Adipose Stromal Cells (ASC) for the Regeneration of Injured Cartilage Display Genetic Stability after In Vitro Culture Expansion

Abstract

Mesenchymal stromal cells are emerging as an extremely promising therapeutic agent for tissue regeneration due to their multi-potency, immune-modulation and secretome activities, but safety remains one of the main concerns, particularly when in vitro manipulation, such as cell expansion, is performed before clinical application. Indeed, it is well documented that in vitro expansion reduces replicative potential and some multi-potency and promotes cell senescence. Furthermore, during in vitro aging there is a decrease in DNA synthesis and repair efficiency thus leading to DNA damage accumulation and possibly inducing genomic instability. The European Research Project ADIPOA aims at validating an innovative cell-based therapy where autologous adipose stromal cells (ASCs) are injected in the diseased articulation to activate regeneration of the cartilage. The primary objective of this paper was to assess the safety of cultured ASCs. The maintenance of genetic integrity was evaluated during in vitro culture by karyotype and microsatellite instability analysis. In addition, RT-PCR array-based evaluation of the expression of genes related to DNA damage signaling pathways was performed. Finally, the senescence and replicative potential of cultured cells was evaluated by telomere length and telomerase activity assessment, whereas anchorage-independent clone development was tested in vitro by soft agar growth. We found that cultured ASCs do not show genetic alterations and replicative senescence during the period of observation, nor anchorage-independent growth, supporting an argument for the safety of ASCs for clinical use.

Adipose-Derived Stem Cells as a Tool in Cell-Based Therapies

“…ASCs exhibit higher genetic stability in long-term culture compared to BM-MSCs (Dahl et al 2008; Neri et al 2013). However, research carried out by at least one research group has shown that karyotype irregularities occur with a frequency of >30 %.…”

Ex Vivo Expanded Mesenchymal Stromal Cell Minimal Quality Requirements for Clinical Application

“…The demonstration of the absence of genetic instability by karyotype analysis should be assessed by molecular [54] or conventional methods (G banding). At least 20 metaphases should be analysed, and in the presence of aberrations, 20 more metaphases are requested, as defined by the General Guidelines and Quality Assurance for Cytogenetics [47,[55][56].…”

The effect of low static magnetic field on osteogenic and adipogenic differentiation potential of human adipose stromal/stem cells

“…The most often applied multipotent stem cells, both as a research tool and in clinical trials, are those isolated from bone marrow multipotent stem cells (BMMSCs) and of adipose origin multipotent stem cells (ASCs). Although both of the above mentioned stem cell populations exhibit many similarities, ASCs are a potentially better candidate for regenerative medicine [2,[4][5][6]. This is because of their high viability and ease of obtaining in large quantities with little donor site related complications or patient discomfort.…”