Mesenchymal Stem Cells Immortalization's Protocols and State-of-Art: A Systematic Review and Meta-Analysis      

Abstract

Mesenchymal stem cells (MSCs) can be derived from several human and animal sources. According to this systematic review, the immortalization of these cells, by viral or gene transfer techniques (plasmid) and non-viral methods, are useful to ensure the reproducibility of the experiments and the prospect of using these cells in clinical studies. The resultant immortalized MSCs cells must undergo through different validation assays in order to prove their safety and phenotypic and genotypic stability; these assays include flow cytometry for specific MSC markers, trilineage differentiation, RT-PCR and qRT-PCR expression analysis for pluripotency genes, karyotype and telomere length and in vivo tumorigenicity assays.

Nanotechnology and bioengineering approaches to improve the potency of mesenchymal stem cell as an off‐the‐shelf versatile tumor delivery vehicle

“…207 Celyvir is an advanced cell therapy medicine developed based on autologous MSCs carrying an oncolytic adenovirus. The clinical trial phase I results on pediatric and adult patients with relapsed/refractory solid tumors have demonstrated that Celyvir is safe and needs further assessment in the phase II stage (362). Several clinical trials have been started in this area, reviewed in the clinical trials section, indicating that this is an attractive field for researchers and promises an exciting future that will open a new window to advanced cell therapy products against relapsed/refractory cancers.…”

“…MSCs have a high proliferation rate while maintaining their differentiation capability, and their marker expression profile is similar to their nonimmortalized counterparts. 362 However, very few studies have performed experiments for side-by-side comparison of primary and immortalized MSCs, other than their differentiation potential and surface marker expression, so there is limited knowledge about changes in biological properties of immortalized MSCs and their long-term in vivo functions. Beckenkamp and colleagues have assessed the impact of MSCs immortalization by TERT gene transfer on the purinergic system, which is a pivotal modulator in many pathophysiological conditions.…”

“…The most common method reported for MSC immortalization is the transfer of specific genes such as the E6/E7 oncogenes of human papilloma‐virus, 360 the early region genes of SV40, 94 and the telomerase gene (TERT) into the MSC 361 . Several studies have reported that the immortalization techniques are nontumorigenic, immortalized MSCs have a high proliferation rate while maintaining their differentiation capability, and their marker expression profile is similar to their nonimmortalized counterparts 362 . However, very few studies have performed experiments for side‐by‐side comparison of primary and immortalized MSCs, other than their differentiation potential and surface marker expression, so there is limited knowledge about changes in biological properties of immortalized MSCs and their long‐term in vivo functions.…”