Toxicological Evaluation of a Probiotic-Based Delivery System for P8 Protein as an Anti-Colorectal Cancer Drug

Abstract

Purpose: This study aimed to toxicological evaluate a probiotics-based delivery system for p8 protein as an anti-colorectal cancer drug. Introduction: Lactic acid bacteria (LAB) have been widely ingested for many years and are regarded as very safe. Recently, a Pediococcus pentosaceus SL4 (PP) strain that secretes the probiotic-derived anti-cancer protein P8 (PP-P8) has been developed as an anti-colorectal cancer (CRC) biologic by Cell Biotech. We initially identified a Lactobacillus rhamnosus (LR)-derived anti-cancer protein, P8, that suppresses CRC growth. We also showed that P8 penetrates specifically into CRC cells (DLD-1 cells) through endocytosis. We then confirmed the efficacy of PP-P8, showing that oral administration of this agent significantly decreased tumor mass (~42%) relative to controls in a mouse CRC xenograft model. In terms of molecular mechanism, PP-P8 induces cell-cycle arrest in G 2 phase through down-regulation of Cyclin B1 and Cdk1. In this study, we performed in vivo toxicology profiling to obtain evidence that PP-P8 is safe, with the goal of receiving approval for an investigational new drug application (IND). Methods: Based on gene therapy guidelines of the Ministry of Food and Drug Safety (MFDS) of Korea, the potential undesirable effects of PP-P8 had to be investigated in intact small rodent or marmoset models prior to first-in-human (FIH) administration. The estimated doses of PP-P8 for FIH are 1.0×10 10 -1.0×10 11 CFU/person (60 kg). Therefore, to perform toxicological investigations in non-clinical animal models, we orally administered PP-P8 at doses of 3.375 × 10 11 , 6.75 × 10 11 , and 13.5×10 11 CFU/kg/day; thus the maximum dose was 800-8000-fold higher than the estimated dose for FIH. Results: In our animal models, we observed no adverse effects of PP-P8 on clinicopathologic findings, relative organ weight, or tissue pathology. In addition, we observed no inflammation or ulceration during pathological necropsy. Conclusion: These non-clinical toxicology studies could be used to furnish valuable data for the safety certification of PP-P8.

Anti-Cancer Roles of Probiotic-Derived P8 Protein in Colorectal Cancer Cell Line DLD-1

“…Finally, we have developed a novel probiotic-based drug delivery system using genetically engineered P. pentosaceus .SL4 (PP-P8) was found to successfully secrete P8 into human intestines [ 14 , 17 ]. Orally administered PP-P8 was found to be safe in rodent and marmoset models [ 12 ], suggesting its possible use in the treatment of patients with CRC. Moreover, PP-P8 has certain important advantages, including low production cost, safety, clear MOA, absence of toxicity, ability to be administered orally, and the ability to be combined with other treatment methods, including chemotherapy, radiation therapy, and targeted therapy.…”

“…Additionally, probiotics have not been reported to be pathogens in any disease [ 11 ]. Due to their safety [ 12 , 13 ] and potency [ 14 , 15 , 16 , 17 ], probiotics may be utilized as drug delivery vehicles, including for the treatment of CRC [ 14 , 18 ].…”

The Debate between the Human Microbiota and Immune System in Treating Aerodigestive and Digestive Tract Cancers: A Review

“…Recently, a novel application of intestinal microbes as delivery systems for CRC therapy was proposed. In this case, the probiotic-derived anticancer protein was delivered selectively to CRC cells in vivo [ 224 ]. Another factor that should be carefully considered is the use of animal in vivo models and their potential for translation into clinical practice.…”