194. Mechanism of Tumour Penetration by Oncolytic Viruses – Investigation in a 3 Dimensional In Vitro Model

Background: Oncolytic viruses are immunotherapeutic agents that can be engineered to encode payloads of interest within the tumor microenvironment to enhance therapeutic efficacy. Their therapeutic potential could be limited by many avenues for immune evasion exerted by the tumor. One such is mediated by adenosine, which induces pleiotropic immunosuppression by inhibiting antitumor immune populations as well as activating tolerogenic stimuli. Adenosine is produced starting from the highly immunostimulatory ATP, which is progressively hydrolyzed to ADP and adenosine by CD39 and CD73. Cancer cells express high levels of CD39 and CD73 ectoenzymes, thus converting immunostimulatory purinergic signal of ATP into an immunosuppressive signal. For this reason, CD39, CD73 and adenosine receptors are currently investigated in clinical trials as targets for metabolic cancer immunotherapy. This is of particular relevance in the context of oncovirotherapy, as immunogenic cell death induced by oncolytic viruses causes the secretion of a high amount of ATP which is available to be quickly converted into adenosine. Methods: Here, we took advantage of adenosine deaminase enzyme that naturally converts adenosine into the corresponding inosine derivative, devoid of immunoregulatory function. We encoded ADA into an oncolytic targeted herpes virus redirected to human HER2. An engineered ADA with an ectopic signal peptide was also generated to improve enzyme secretion (ADA-SP). Results: Insertion of the expression cassette was not detrimental for viral yield and cancer cell cytotoxicity. The THV_ADA and THV_ADA-SP successfully mediated the secretion of functional ADA enzyme. In in vitro model of human monocytes THP1, this ability of THV_ADA and THV_ADA-SP resulted in the retrieval of eADO-exposed monocytes replication rate, suggesting the proficiency of the viruses in rescuing the immune function. Conclusions: Encoding ADA into oncolytic viruses revealed promising properties for preclinical exploitation.

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A novel 3-dimensional culture system as an in vitro model for studying oral cancer cell invasion

International Journal of Experimental Pathology ◽

10.1111/j.0959-9673.2005.00441.x ◽

2005 ◽

Vol 86 (6) ◽

pp. 365-374 ◽

Cited By ~ 18

Author(s):

Hai S. Duong ◽

Anh D. Le ◽

Qunzhou Zhang ◽

Diana V. Messadi

Keyword(s):

Oral Cancer ◽

Cancer Cell ◽

Cell Invasion ◽

Culture System ◽

In Vitro Model ◽

Cancer Cell Invasion ◽

3 Dimensional ◽

Oral Cancer Cell ◽

Vitro Model

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Hyperosmolar Potassium (K+) Treatment Suppresses Osteoarthritic Chondrocyte Catabolic and Inflammatory Protein Production in a 3-Dimensional In Vitro Model

Cartilage ◽

10.1177/1947603517734028 ◽

2017 ◽

Vol 10 (2) ◽

pp. 186-195 ◽

Cited By ~ 7

Author(s):

Josh Erndt-Marino ◽

Erik Trinkle ◽

Mariah S. Hahn

Keyword(s):

Inflammatory Mediators ◽

Protein Production ◽

In Vitro Model ◽

Culture Media ◽

Dependent Manner ◽

Proof Of Concept ◽

3 Dimensional ◽

Inflammatory Protein ◽

Vitro Model

Objective The main goal of this study was to provide a proof-of-concept demonstrating that hyperosmolar K+ solutions can limit production of catabolic and inflammatory mediators in human osteoarthritic chondrocytes (OACs). Methods A 3-dimensional in vitro model with poly(ethylene glycol) diacrylate (PEGDA) hydrogels was used. Catabolic and pro-inflammatory protein production from encapsulated OACs was assessed following culture for 1 or 7 days in the presence or absence of 80 mM K+ gluconate, 80 mM sodium (Na+) gluconate, or 160 mM sucrose, each added to culture media (final osmolarity ~490 mOsm). Results Relative to untreated controls, OACs treated with hyperosmolar (80 mM Na+ gluconate or 160 mM sucrose) solutions produced lower levels of catabolic and inflammatory mediators in a marker- and time-dependent manner (i.e., MMP-9 after 1 day; MCP-1 after 7 days ( P ≤ 0.015)). In contrast, OAC treatment with 80 mM K+ gluconate reduced catabolic and inflammatory mediators to a greater extent (both the number of markers and degree of suppression) relative to untreated, Na+ gluconate, or sucrose controls (i.e., MMP-3, -9, -13, TIMP-1, MCP-1, and IL-8 after 1 day; MMP-1, -3, -9, -13, TIMP-1, MCP-1, and IL-8 after 7 days ( P ≤ 0.029). Conclusions Hyperosmolar K+ solutions are capable of attenuating protein production of catabolic and inflammatory OA markers, providing the proof-of-concept needed for further development of a K+-based intra-articular injection for OA treatment. Moreover, K+ performed significantly better than Na+- or sucrose-based solutions, supporting the application of K+ toward improving irrigation solutions for joint surgery.

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