The first Japanese biobank of patient‐derived pediatric acute lymphoblastic leukemia xenograft models

A lack of practical resources in Japan has limited preclinical discovery and testing of therapies for pediatric relapsed and refractory acute lymphoblastic leukemia (ALL), which has poor outcomes. Here, we established 57 patient-derived xenografts (PDXs) in NOD.Cg-Prkdcscidll2rgtm1Sug/ShiJic (NOG) mice and created a biobank by preserving PDX cells including three extramedullary relapsed ALL PDXs. We demonstrated that our PDX mice and PDX cells mimicked the biological features of relapsed ALL and that PDX models reproduced treatment-mediated clonal selection. Our PDX biobank is a useful scientific resource for capturing drug sensitivity features of pediatric patients with ALL, providing an essential tool for the development of targeted therapies

Japan’s contribution to an ongoing global pediatric cancer clinical trial: The experience of the National Cancer Center Hospital (NCCH) in Tokyo

Compared to Europe and the United States, where the development of pediatric oncology drugs is mandated by law, Japan hosts fewer clinical trials. This can lead to a significant drug lag, especially in the case of treatments for pediatric solid tumors. Notably, regulatory authorities and the government have initiated discussions on strategies to mitigate Japan’s drug lag problem in pediatric oncology. Over the past decade, we have actively sought opportunities to participate in international collaborative clinical trials through Japan’s involvement in ACCELERATE and its predecessor organizations. This approach has aimed to address the issue above, coinciding with the ongoing centralization of medical care and advancements in genomic medicine, among other systems that support pediatric cancer care in Japan. Inspired by the ACCELERATE initiatives and in response to patient advocacy groups’ requests for new pediatric oncology drugs, Japan established its inaugural pediatric oncology support platform in 2021, the National Childhood Cancer Consortium (N3C). N3C comprises patient advocacy groups, industries, and academia. This work outlines the current status of pediatric drug development in Japan and highlights the initial successful experience of NCCH’s participation in a global clinical trial through ACCELERATE resulting in rapid preparation and patient recruitment. Participation of Asian countries including Japan in global collaborative clinical trials may benefit both pharmaceutical companies and the participating countries partnering to advance the development of pediatric oncology drugs

Transforming Potential of Src Family Kinases Is Limited by the Cholesterol-Enriched Membrane Microdomain▿

The upregulation of Src family kinases (SFKs) has been implicated in cancer progression, but the molecular mechanisms regulating their transforming potentials remain unclear. Here we show that the transforming ability of all SFK members is suppressed by being distributed to the cholesterol-enriched membrane microdomain. All SFKs could induce cell transformation when overexpressed in C-terminal Src kinase (Csk)-deficient fibroblasts. However, their transforming abilities varied depending on their affinity for the microdomain. c-Src and Blk, with a weak affinity for the microdomain due to a single myristate modification at the N terminus, could efficiently induce cell transformation, whereas SFKs with both myristate and palmitate modifications were preferentially distributed to the microdomain and required higher doses of protein expression to induce transformation. In contrast, disruption of the microdomain by depleting cholesterol could induce a robust transformation in Csk-deficient fibroblasts in which only a limited amount of activated SFKs was expressed. Conversely, the addition of cholesterol or recruitment of activated SFKs to the microdomain via a transmembrane adaptor, Cbp/PAG1, efficiently suppressed SFK-induced cell transformation. These findings suggest that the membrane microdomain spatially limits the transforming potential of SFKs by sequestering them away from the transforming pathways

Simple and Practical Two-Photon Ionization Detection in High-Performance Liguid Chromatography

A method for simple and practical two-photon ionization detection for HPLC effluents was demonstrated. A peak detector can replace a boxcar integrator. The system was applied to several types of samples and eluents