Adenovirus platform enhances transduction efficiency of human mesenchymal stem cells: An opportunity for cellular carriers of targeted TRAIL-based TR3 biologics in ovarian cancer

Abstract

Clinical application of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-based cancer therapeutics has not reached optimal potencies in part due to inadequate drug stability and inefficiencies in cancer-selective drug delivery. As such, innovative strategies regarding drug design and delivery are of utmost importance to achieve improved treatment results. With our current study, we aimed at exploring the groundwork for a two-stage targeting concept, which is based on the intrinsic tumor homing capacity of mesenchymal stem cells (MSCs) as cellular drug factories for the in situ production of our newly designed and biomarker-targeted TRAIL-based TR3 therapeutics. Since MSCs are primary cells, capable in vitro of only a limited number of cell divisions, identification of suitable strategies for their efficient genetic manipulation is of critical importance. We chose adenoviral (Ad) vectors as a transduction vehicle due to its ability to infect dividing and non-dividing cells and because of their limited restrictions regarding the packaging capacity of their genetic payload. In order to enhance the transduction efficacy of MSCs using Ad5 wild-type-based vectors, we tested a variety of fiber knob modifications on a panel of patient-derived MSC lines established from adipose tissue. We identified Ad5pK7, an Ad5 vector containing a polylysine fiber knob modification, exhibiting the highest transduction rates across a panel of 16 patient-derived MSC lines. We further demonstrated that MSCs could be efficiently transduced with an Ad5pK7 vector containing membrane-anchored and secreted TR3 expression units, including the MUC16 (CA125)-targeted variant Meso64-TR3. In both in vitro and in vivo experiments, MSC-derived Meso64-TR3 was far more potent on MUC16-expressing ovarian cancer compared to its non-targeted TR3 counterpart. Our findings thus provide the foundation to initiate further preclinical investigations on MSC-mediated treatment options in ovarian cancer using biomarker-targeted TR3-based biologics.

Mesenchymal Stem Cells in Adipose Tissue and Extracellular Vesicles in Ovarian Cancer Patients: A Bridge toward Metastatic Diffusion or a New Therapeutic Opportunity?

“…Nonetheless, its use has been limited often by low stability and inefficient delivery in the tumor site [88]. Kuroki and colleagues used a TRAIL-based molecule called TR3 and transduced the TR3 expressing gene to ADSCs via an adenoviral vector [79]. Transduced ADSCs efficiently expressed TR3 and secreted it in the extracellular space.…”

Understanding and addressing barriers to successful adenovirus-based virotherapy for ovarian cancer

“…Morrison et al were able to protect the vector from neutralizing antibodies and demonstrated significantly lower tumor load and absence of inflammatory toxicities by coating Ad5 with poly (hydroxypropyl methacrylamide (pHPMA) and retargeting to EGFR with EGF or cetuximab [151,152]. Thanks to their natural tumor tropism and immunomodulatory properties, mesenchymal stem cells (MSCs) of different origins have been used as carriers of oncolytic Ads [153][154][155], increasing targeted delivery and reducing the hepatic uptake and systemic toxicity seen in clinical trials of vectors such as Ad5-Δ24RGD [156]. Menstrual blood MSCs (MenSCs) were successfully used to deliver an Ad5/3Δ24 CRAd with microenvironment-responsive elements and the SPARC promoter without being blocked by antibodies present in the ascites, which also contain soluble factors that can serve as transcriptional enhancers [157].…”

Streamlined procedure for gene knockouts using all-in-one adenoviral CRISPR-Cas9

“…Among the most widely used viral vectors, lentivirus and adeno-associated virus (AAV) are preferred for human gene therapy applications, but adenovirus (AV) has important advantages as a research tool 17,18 . AV has the highest transduction efficiency in diverse target cells 16,19,20 ; unlike lentivirus, its genome does not integrate into the host genome, thus reducing off-target mutations; and AV has a substantially higher genome capacity than AAV 21 . We have used this capacity to co-package three CRISPR-Cas9 components along with their promoters: Cas9, sgRNA and a fluorescent protein to aid in sorting for transduced cells.…”