Site-Specific Integration of TRAIL in iPSC-Derived Mesenchymal Stem Cells for Targeted Cancer Therapy

Abstract

Mesenchymal stem cells (MSCs) are a promising cellular vehicle for transferring anti-cancer factors to malignant tumors. Currently, a variety of anti-cancer agents, including the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), have been loaded into MSCs derived from a range of sources through different engineering methods. These engineered MSCs exhibit enormous therapeutic potential for various cancers. To avoid the intrinsic defects of MSCs derived from tissues and the potential risk of viral vectors, TRAIL was site-specifically integrated into the ribosomal DNA (rDNA) locus of human-induced pluripotent stem cells (iPSCs) using a non-viral rDNA-targeting vector and transcription activator-like effector nickases (TALENickases). These genetically modified human iPSCs were differentiated into an unlimited number of homogeneous induced MSCs (TRAIL-iMSCs) that overexpressed TRAIL in both culture supernatants and cell lysates while maintaining MSC-like characteristics over continuous passages. We found that TRAIL-iMSCs significantly induced apoptosis in A375, A549, HepG2, and MCF-7 cells in vitro. After intravenous infusion, TRAIL-iMSCs had a prominent tissue tropism for A549 or MCF-7 xenografts and significantly inhibited tumor growth through the activation of apoptotic signaling pathways without obvious side effects in tumor-bearing mice models. Altogether, our results showed that TRAIL-iMSCs have strong anti-tumor effects in vitro and in vivo on a range of cancers. This study allows for the development of an unlimited number of therapeutic gene-targeted MSCs with stable quality and high homogeneity for cancer therapy, thus highlighting a universal and safe strategy for stem cell-based gene therapy with high potential for clinical applications.

Targeting the tumor stroma for cancer therapy

“…Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) is a type II membrane-bound protein capable of inducing apoptosis in various cancer cells. TRAIL-expressing MSCs exhibited directional migration and infiltration toward tumor tissues, extended animal survival and contributed to overcoming drug resistance [489][490][491]. Furthermore, exogenous microRNAs delivered by MSCs also assist in antitumor therapy, which deserves further clinical evaluation [492][493][494].…”

Cytochalasin B-Induced Membrane Vesicles from TRAIL-Overexpressing Mesenchymal Stem Cells Induce Extrinsic Pathway of Apoptosis in Breast Cancer Mouse Model

“…However, despite the induction of necrosis in some areas of the tumor, the administration of CIMVs-TRAIL did not induce any significant decrease in the tumor growth rate. Apparently, this level of necrosis induction was not sufficient to influence tumor progression since, in other studies, the percentage of necrotic tissue after TRAIL delivery reached 42% [48]. Additionally, it has been shown that the introduction of vesicles together with tumor cells can more effectively delay the development of the tumor [19].…”

“…Previous studies have reported that genetically engineered MSCs with TRAIL overexpression could exhibit an inhibitory effect on the growth of some TRAIL-resistant cells, such as ileocecal adenocarcinoma HCT8 cells [47]. Moreover, iPSC-derived MSCs that were site-specifically integrated with TRAIL gene into the genome caused TRAIL-induced apoptosis in resistant lung adenocarcinoma A549 cells and MCF-7 cells in vitro and in vivo [48].…”

“…Multiple local administrations of CIMVs-TRAIL into the tumor were associated with the induction of tumor cell death in the CIMV-TRAIL injection group paralleled by remarkable CASP8 activation, which is generally consistent with previous studies on TRAIL antitumor activity. For example, the injection of iMSCs-TRAIL led to the induction of necrosis in tumor tissues in the animal model of breast cancer MCF-7 [48]. In addition, the level of the mRNA gene expression of the key protein of the extrinsic apoptosis pathway CASP8 was also increased in tumor tissue injected with CIMVs-TRAIL, indicating the activation of TRAIL-mediated apoptosis in tumor cells.…”

“Remote adipose tissue-derived stromal cells of patients with lung adenocarcinoma generate a similar malignant microenvironment of the lung stromal counterpart”

“…The biological interaction between MSC and tumor is complex and enormously debated. Several controversies exist about the potential of MSC to enhance or to even arrest tumorigenicity, because of their double faced behaviour: tumor-tropism (hence tested as vehicles for anticancer genes targeting cancer cells or as enhancement of the CAR-T immunotherapy) [4,5] and immunomodulative features, but also pro-metastatic functions [6][7][8], trans-differentiation into cancer-associated fibroblasts and drug resistance [9] and the parallel ability to overturn the immune system [10][11][12][13], activation of autophagy and neo-angiogenesis [14], therefore contributing to tumor evolution. This discrepancy also includes exosomes-derived MSC, considered both an intriguing therapeutic tool for drug delivery and main biological mediators of several supporting tumor molecular process [15].…”