Shingo Kato

Background/Objectives: Acute cholecystitis in patients with malignant biliary obstruction (MBO) is challenging to manage. Evidence for endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using double-pigtail plastic stents (DPPS) in this setting remains limited. We evaluated the efficacy and safety of EUS-GBD using DPPS for acute cholecystitis in patients with MBO. Methods: We retrospectively reviewed 41 consecutive patients who underwent EUS-GBD using DPPS at two centers. The primary endpoint was technical success; secondary endpoints included clinical success, adverse events, recurrence, and subsequent oncologic treatment. Results: Technical success was achieved in 95.1% (39/41), with clinical success in all technically successful cases. Adverse events included biliary peritonitis (14.6%) and procedure-related DPPS migration (2.4%). Recurrence occurred in 2.6% of patients. Systemic therapy was resumed in 10 of 18 patients (55.6%) at a median of 15 days after EUS-GBD. Conclusions: EUS-GBD using DPPS achieved high technical and clinical success rates with a low recurrence rate in selected patients with acute cholecystitis and MBO. Systemic therapy could be resumed in a subset of patients following successful drainage. These findings suggest that DPPS-based EUS-GBD may be a feasible internal drainage option in this setting, although prospective comparative studies are needed to further establish its safety and effectiveness.

Pancreatic ductal adenocarcinoma (PDAC) has one of the poorest prognoses of all cancer types. Immune checkpoint inhibitors (ICIs) are currently not indicated for patients with PDAC except for those with high microsatellite instability. In this study, we developed an immunocompetent orthotopic transplant mouse model with Kras and Trp53 mutations, characterized by high fibrosis and an immunosuppressive tumor microenvironment, closely mimicking human PDAC lesions. This model provides a robust platform for investigating strategies for improving ICI efficacy. We observed that ICI monotherapy yielded minimal efficacy, whereas anti‐CD40 agonist antibody (aCD40) monotherapy prolonged survival despite its low impact on primary tumor volume. Moreover, ICIs + aCD40 combination therapy not only extended survival but also significantly reduced tumor burden. These effects were accompanied by enhanced dendritic cell migration to the lymph nodes and T cell priming and activation. Moreover, the expression of immunosuppressive markers in tumor‐associated macrophages was decreased. Indeed, gene expression analyses of infiltrating immune cells have revealed a shift in the tumor microenvironment from an immune‐tolerant state to an immune‐activated state. Our findings suggest that combination therapy with ICIs and aCD40 is a promising treatment strategy for patients with PDAC.

Homologous recombination (HR) and mismatch repair (MMR) act as guardians of the human genome, and defects in HR or MMR are causative in at least a quarter of all malignant tumors. Although these DNA repair-deficient tumors are eligible for effective targeted therapies, fully reliable diagnostic strategies based on functional assay have yet to be established, potentially limiting safe and proper application of the molecular targeted drugs. Here we show that transient transfection of artificial DNA substrates enables ultrarapid detection of HR and MMR. This finding led us to develop a diagnostic strategy that can determine the cellular HR/MMR status within one day without the need for control cells or tissues. Notably, the accuracy of this method allowed the discovery of a pathogenic RAD51D mutation, which was missed by existing companion diagnostic tests. Our methods, termed HR eye and MMR eye, are applicable to frozen tumor tissues and roughly predict the response to therapy. Overall, the findings presented here could pave the way for accurately assessing malignant tumors with functional defects in HR or MMR, a step forward in accelerating precision medicine.

Mutations of KRAS, CDKN2A, TP53, and SMAD4 are the four major driver genes for pancreatic ductal adenocarcinoma (PDAC), of which mutations of KRAS and TP53 are the most frequently recognized. However, molecular‐targeted therapies for mutations of KRAS and TP53 have not yet been developed. To identify novel molecular targets, we newly established organoids with the Kras mutation (Kras^muOR) and Trp53 loss of function using Cre transduction and CRISPR/Cas9 (Kras^mu/p53^muOR) from murine epithelia of the pancreatic duct in Kras^LSL‐G12D mice, and then analyzed the proteomic and metabolomic profiles in both organoids by mass spectrometry. Hyperfunction of the glycolysis pathway was recognized in Kras^mu/p53^muOR compared with Kras^muOR. Loss of function of triosephosphate isomerase (TPI1), which is involved in glycolysis, induced a reduction of cell proliferation in human PDAC cell lines with the TP53 mutation, but not in PDAC or in human fibroblasts without TP53 mutation. The TP53 mutation is clinically recognized in 70% of patients with PDAC. In the present study, protein expression of TPI1 and nuclear accumulation of p53 were recognized in the same patients with PDAC. TPI1 is a potential candidate therapeutic target for PDAC with the TP53 mutation.

Mismatch ratio of genomic alterations in the prospective cohort

Summary of the retrospective cohort

Genomic profiling of EGFR, PTEN, and TERT in IDH-wildtype lower-grade astrocytomas

Illustrative mismatch cases in the prospective cohort

IDH- and pTERT-wildtype gliomas at intraoperative integrated diagnosis in the retrospective cohort