StemPanTox: A fast and wide-target drug assessment system for tailor-made safety evaluations using personalized iPS cells.

An alternative model that reliably predicts human-specific toxicity is necessary because the translatability of effects on animal models for human disease is limited to context. Previously, we developed a method that accurately predicts developmental toxicity based on the gene networks of undifferentiated human embryonic stem (ES) cells. Here, we advanced this method to predict adult toxicities of 24 chemicals in six categories (neurotoxins, cardiotoxins, hepatotoxins, two types of nephrotoxins, and non-genotoxic carcinogens) and achieved high predictability (AUC = 0.90-1.00) in all categories. Moreover, we screened for an induced pluripotent stem (iPS) cell line to predict the toxicities based on the gene networks of iPS cells using transfer learning of the gene networks of ES cells, and predicted toxicities in four categories (neurotoxins, hepatotoxins, glomerular nephrotoxins, and non-genotoxic carcinogens) with high performance (AUC = 0.82-0.99). This method holds promise for tailor-made safety evaluations using personalized iPS cells.

Qualitative analysis of actual Standard for Exchange of Nonclinical Data (SEND) datasets for Data Domains: Proposition from Japan Pharmaceutical Manufacturers Association SEND Taskforce Team on standardization of nonclinical data.

The Standard for Exchange of Nonclinical Data (SEND) has been adopted by the US FDA, which has required pharmaceutical companies who are developing new drugs for the US market to implement SEND. The Japan Pharmaceutical Manufacturers Association (JPMA) SEND Taskforce Team responded to this situation by starting a project to better understand the contents of SEND datasets. The project focused on domains generally included in the SEND domains for single- and repeat-dose general toxicology studies, and surveyed what kind of information are populated in which domains and in what way. The qualitative analysis of the results indicated that variations exist based on whether or not an individual variable was populated and on how the variable was populated. The Taskforce Team recommends reducing variations not only in the SEND datasets but also in the descriptions in the study protocol and/or final study report. Reduction of such variations should lead to higher quality datasets with powerful and increased searchability so that accumulated SEND datasets should become more valuable. These efforts would provide regulatory agencies with easier review of SEND datasets, which contributes to efficient development of new drug candidates.

Considerations of the Japanese Research Working Group for the ICH S6 & Related Issues Regarding Nonclinical Safety Assessments of Oligonucleotide Therapeutics: Comparison with Those of Biopharmaceuticals.

This white paper summarizes the current consensus of the Japanese Research Working Group for the ICH S6 & Related Issues (WGS6) on strategies for the nonclinical safety assessment of oligonucleotide-based therapeutics (ONTs), specifically focused on the similarities and differences to biotechnology-derived pharmaceuticals (biopharmaceuticals). ONTs, like biopharmaceuticals, have high species and target specificities. However, ONTs have characteristic off-target effects that clearly differ from those of biopharmaceuticals. The product characteristics of ONTs necessitate specific considerations when planning nonclinical studies. Some ONTs have been approved for human use and many are currently undergoing nonclinical and/or clinical development. However, as ONTs are a rapidly evolving class of drugs, there is still much to learn to achieve optimal strategies for the development of ONTs. There are no formal specific guidelines, so safety assessments of ONTs are principally conducted by referring to published white papers and conventional guidelines for biopharmaceuticals and new chemical entities, and each ONT is assessed on a case-by-case basis. The WGS6 expects that this report will be useful in considering nonclinical safety assessments and developing appropriate guidelines specific for ONTs.

Genetic defect in phospholipase Cδ1 protects mice from obesity by regulating thermogenesis and adipogenesis.

OBJECTIVE: Regulation of obesity development is an important issue to prevent metabolic syndromes. Gene-disrupted mice of phospholipase Cδ1 (PLCδ1), a key enzyme of phosphoinositide turnover, seemed to show leanness. Here we examined whether and how PLCδ1 is involved in obesity. RESEARCH DESIGN AND METHODS: Weight gain, insulin sensitivity, and metabolic rate in PLCδ1(-/-) mice were compared with PLCδ1(+/-) littermate mice on a high-fat diet. Thermogenic and adipogenetic potentials of PLCδ1(-/-) immortalized brown adipocytes and adipogenesis of PLCδ1-knockdown (KD) 3T3L1 cells, or PLCδ1(-/-) white adipose tissue (WAT) stromal-vascular fraction (SVF) cells, were also investigated. RESULTS: PLCδ1(-/-) mice showed marked decreases in weight gain and mass of epididymal WAT and preserved insulin sensitivity compared with PLCδ1(+/-) mice on a high-fat diet. In addition, PLCδ1(-/-) mice have a higher metabolic rate such as higher oxygen consumption and heat production. When control immortalized brown adipocytes were treated with thermogenic inducers, expression of PLCδ1 was decreased and thermogenic gene uncoupling protein 1 (UCP1) was upregulated to a greater extent in PLCδ1(-/-) immortalized brown adipocytes. In contrast, ectopic expression of PLCδ1 in PLCδ1(-/-) brown adipocytes induced a decrease in UCP expression, indicating that PLCδ1 negatively regulates thermogenesis. Importantly, accumulation of lipid droplets was severely decreased when PLCδ1-KD 3T3L1 cells, or PLCδ1(-/-) WAT SVF cells, were differentiated, whereas differentiation of PLCδ1(-/-) brown preadipocytes was promoted. CONCLUSIONS: PLCδ1 has essential roles in thermogenesis and adipogenesis and thereby contributes to the development of obesity.

Drug-selected co-expression of P-glycoprotein and gp91 in vivo from an MDR1-bicistronic retrovirus vector Ha-MDR-IRES-gp91.

BACKGROUND: Retroviral transduction of human hematopoietic stem cells is an attractive strategy in gene therapy; however, transduction efficiency and duration of transgene expression may not be satisfactory in current protocols. Co-expression of a human multidrug resistance gene (MDR1) with a therapeutic gene affords selectable growth advantage to genetically modified cells. METHODS: A bicistronic retrovirus vector, Ha-MDR-IRES-gp91, was constructed for the co-expression of MDR1 and gp91, a gene responsible for X-linked chronic granulomatous disease (X-CGD). Drug-selected co-expression of P-glycoprotein and gp91 was evaluated in transduced cells. RESULTS: Epstein-Barr virus-transformed B cells from X-CGD patients transduced with Ha-MDR-IRES-gp91 co-expressed human P-glycoprotein and gp91, and acquired superoxide-generating activity. Human CD34-positive cells from an X-CGD patient were transduced with Ha-MDR-IRES-gp91 and subsequently treated with 2 ng/ml vincristine. After 13 days, 20% of Ha-MDR-IRES-gp91-transduced cells were P-glycoprotein- and gp91-positive by FACS analysis. The superoxide-generating activity of the transduced population was 27% of that of normal cells. Mice transplanted with Ha-MDR-IRES-gp91-transduced bone marrow cells showed co-expression of P-glycoprotein and gp91 in peripheral blood mononuclear cells. By administering paclitaxel, the proportions of P-glycoprotein- and gp91-positive cells were increased in all the four mice examined. When mice transplanted with Ha-MDR-IRES-gp91-transduced cells were repeatedly administered paclitaxel, the ratios of P-glycoprotein- and gp91-positive cells were maintained for over 1 year. CONCLUSIONS: These results suggest that MDR1-bicistronic vectors may be useful to select the transduced hematopoietic cells in vivo. This may lead to the sustained expression of transgenes in the blood cells of patients treated with stem cell gene therapy.