Paneth cell metaplasia (PCM) is a phenomenon in which Paneth cells, typically found in the small intestine, appear in the colonic epithelium of patients with ulcerative colitis (UC). Our study demonstrates that the PCM occurrence correlates with disease duration and active inflammation. Furthermore, we identified IL-22, an inflammation-associated cytokine, as a key regulator that promotes PCM formation in the colonic epithelium through suppression of Notch signaling and induces REG3A expression within metaplastic niches. In vitro, we show that Reg3a directly enhances cell proliferation and promotes wound healing using mouse colonic organoids. In vivo, Reg3aΔIEC mice in both acute and chronic DSS-induced colitis models exhibit delayed wound healing. Additionally, studies conducted with patient-derived human colonic organoids revealed that REG3A administration stimulates cell proliferation and accelerates wound healing. Together, these findings support a protective role of PCM-associated REG3A in the colonic epithelium of patients with UC.

Immune deficiency and dysregulation (IDD)-associated classical Hodgkin lymphoma (cHL) is one of the common subtypes of IDD-related lymphomas. Patients with IDD-cHL are typically treated with the same chemotherapeutic regimens as those with sporadic cHL. However, the clinical differences between these groups remain poorly elucidated. To assess the impact of immune status on clinical features and treatment outcomes, 44 patients who were newly diagnosed with cHL and treated at our institution, including 12 with IDD-cHL, were retrospectively analyzed. Epstein–Barr virus-encoded small RNA positivity was significantly more common in patients with IDD-cHL than in those with sporadic cHL. Nevertheless, the baseline laboratory parameters did not significantly differ between the two groups. Patients with IDD-cHL had significantly higher rates of neutropenia than those with sporadic cHL, resulting in reduced relative dose intensity. However, the two groups were similar in terms of complete response and progression-free survival rates. Based on a prognostic analysis, serum lactate dehydrogenase (LDH) and soluble interleukin-2 receptor (sIL-2R) levels were associated with prognosis. However, their prognostic implications were contrasting in the two immune status groups. To integrate these markers, the prognostic value of the sIL-2R-to-LDH ratio (cutoff: 3.58) was evaluated. A higher ratio was significantly associated with poorer prognosis in sporadic cHL (p < 0.01). Meanwhile, in IDD-cHL, a lower ratio was associated with worse outcomes (p = 0.07). According to these findings, the overall clinical presentation of cHL and the efficacy of its treatment are significantly consistent regardless of immune status. However, the prognostic significance of specific biomarkers is distinct. The sIL-2R-to-LDH ratio may represent a broadly applicable prognostic marker, and its interpretation should be adapted according to the patient’s immune background.

Introduction:Epithelioid angiomyolipoma is a subtype of perivascular epithelioid cell tumors that may exhibit malignant behavior. While mammalian target of rapamycin inhibitors are commonly used for systemic treatment, the efficacy of immune checkpoint inhibitors remains unclear. Case Presentation:A 58-year-old man was diagnosed with epithelioid angiomyolipoma after partial nephrectomy of a right renal mass. The tumor recurred locally, and multiple lung metastases developed despite surgical resection. Nivolumab was initiated after disease progression on everolimus, resulting in durable disease control for over 3 years. Immunohistochemistry revealed high PD-L1 expression and CD8+ T-cell infiltration within the primary tumor. Conclusion:Immune checkpoint inhibitors may be effective treatment options for malignant epithelioid angiomyolipoma with PD-L1 expression and CD8+ T-cell infiltration.

Lymphoid proliferations and lymphomas associated with immune deficiency and dysregulation (LP/L-IDD) are rare entities associated with the use of immunosuppressive drugs (ISD) for autoimmune conditions. Composite lymphomas, featuring both B-cell and T-cell lymphomas, are infrequent, and their occurrence as LP/L-IDD is rare. We herein report the case of a 70-year-old man with right pleural effusion and lymphadenopathy, who was treated with infliximab for sarcoidosis and ankylosing spondylitis. A biopsy revealed a composite lymphoma of DLBCL and PTCL-NOS. CHOP chemotherapy led to significant remission. This case report emphasizes the need to consider lymphoma in patients with autoimmune diseases such as sarcoidosis and ankylosing spondylitis, especially those treated with ISDs.

BACKGROUND:Gastric cancer survival rates vary across countries due to differences in access to early diagnostic testing and healthcare quality. Endoscopy, though accurate, is not feasible for mass screening. The ABC method, which combines serum Helicobacter pylori (Hp) antibody and pepsinogen tests, has shown promise for gastric cancer risk stratification in Japan. However, its applicability in populations with diverse CagA status and subtypes remains uncertain. MATERIALS AND METHODS:This prospective study in Brazil evaluated the performance of the ABC method in an endoscopy-referred cohort with a heterogeneous distribution of Hp CagA status and subtypes. A recently validated immunohistochemical method was applied to formalin-fixed paraffin-embedded gastric biopsy samples to assess Hp infection, CagA expression, and CagA subtypes. Gastric pathology was evaluated using the updated Sydney System and OLGA/OLGIM staging and correlated with serum Hp antibody and pepsinogen levels in 586 patients, including 122 Japanese Brazilians. RESULTS:Immunohistochemistry achieved a 98% success rate (577/586). The prevalence of Hp infection was 48%, with Western-type CagA(+) (26%) and CagA(-) (18%) strains predominating. East Asian-type CagA(+) strains (4%) were observed primarily among Japanese Brazilians, particularly in second-generation individuals. Gastric pathology and serum markers differed significantly across CagA status and subtypes. Despite these differences, the ABC method's negative predictive values (NPVs) across all groups other than Group A (negative for both tests) remained high (97%/97% or 98%/100% for detecting OLGA/OLGIM stages ≥ II or ≥ III, and 94%/98% or 99%/100% for detecting antrum/corpus inflammation scores ≥ 2 or 3, respectively). CONCLUSIONS:These findings demonstrate the clinical relevance of CagA diversity for gastric cancer risk assessment. Although limited to an endoscopy-referred cohort, the ABC method reliably identified low-risk individuals (Group A) and may help reduce unnecessary endoscopies in screening programs, regardless of CagA status and subtypes. Broader, population-based studies are needed to validate its generalizability and optimize its implementation.

Esophageal squamous cell carcinoma (ESCC) is a deadly cancer with a poor prognosis and a high recurrence rate after chemotherapy, posing a significant clinical challenge. To elucidate the molecular basis of chemotherapy (chemo)-resistance and to develop methods to effectively eliminate chemo-resistant tumor clones, we established an ESCC organoid (ESCCO) library from 24 ESCC patients of various stages, ages, and treatments. These ESCCOs faithfully recapitulate the oncogenic mutations observed in the original ESCC tissues and manifest tumorigenic properties when xenografted. The ESCCOs respond differently to cisplatin and 5-fluorouracil, chemotherapeutic agents commonly used to treat ESCC patients, with 7 ESCCOs exhibiting potent chemo-resistance. Notably, the chemo-resistant ESCCOs show higher genes involved in antioxidant stress response pathways and more accessible chromatin at their loci than the sensitive ESCCOs. These genes can serve as valuable biomarkers to stratify chemo-resistant ESCCs in histopathological specimens. Through drug screening using the ESCCO library, we reveal that fedratinib effectively induces cell death in chemo-resistant ESCCOs. Collectively, our human ESCCO model offers novel insights into the mechanism of chemo-resistance in ESCCs, which is critical for developing effective therapeutic approaches to eradicate the recurrence of ESCCs.

Oncogenic events perturb cerebellar development leading to medulloblastoma, a common childhood brain malignancy. Molecular analyses classify medulloblastoma into the WNT, SHH, Group 3 and Group 4 subgroups. Bone morphogenetic protein (BMP) pathways control cerebellar development and have been linked to the progression of medulloblastoma disease, with major remaining gaps in their mechanistic and clinically-relevant roles. We therefore aimed at exploring BMP mechanisms of action in medulloblastoma. Patient-derived tumors from different subgroups were analyzed in mouse xenografts, complemented by independent tumor immunohistochemical analysis. Cell-based assays analyzed signaling mechanisms. Medulloblastoma cell orthotopic xenografts analyzed tumor growth and metastasis in vivo. Active BMP signaling, detected as nuclear and phosphorylated SMAD1/5, characterized several medulloblastoma subgroups, with enrichment in Group 4, SHH and Group 3 tumors. Spatial transcriptomics in tumor areas, complemented by transcriptomic analysis of multiple cell models, identified BMP-dependent transcriptional induction of the LIM-homeobox gene 2 (LHX2). BMP signaling via SMADs induced LHX2 expression and LHX2 transcriptionally induced BMP type I receptor (ACVR1) expression by association with the proximal promoter region of the ACVR1 gene. BMP signaling and LHX2 gain-of-function expression led to enriched stemness and associated chemoresistance in medulloblastoma cultures. In-mouse orthotopic transplantation of paired primary/recurrent Group 4 medulloblastoma cell populations, correspondingly expressing LHX2-low/BMP-low signaling and LHX2-high/BMP-high signaling, ascribed to the latter (high) group more efficient tumor propagation and spinal cord metastatic potential. Depletion of LHX2 in these recurrent tumor cells suppressed both BMP signaling and tumor propagation in vivo. Thus, LHX2 cooperates with, and enhances, oncogenic BMP signaling in medulloblastoma tumors. The molecular pathway that couples LHX2 function to BMP signaling in medulloblastoma deepens our understanding this malignancy.

The tumor microenvironment comprises various cell types, and cancer-associated fibroblasts (CAFs) are crucial contributors to cancer progression and metastasis. CAFs also play an important role in esophageal squamous cell carcinoma and have been extensively studied in this context. However, the association between CAFs and progression across pathological stages has not yet been reported. To identify these specific CAFs, we used a case-oriented approach for single-cell RNA sequencing. Consequently, we identified 3 CAF clusters classified as myofibroblastic CAFs (myCAFs), which increased in number as the cancer progressed. Pathway analysis revealed that the 3 CAF clusters had distinct properties. These CAFs were named MMP13+, COL11A1+, and SFRP4+ myCAFs based on their characteristic gene expression. We also investigated the distribution of various immune cells within the tumor microenvironment associated with the 3 different CAF clusters. The results revealed the presence of different types of immune cells, including M2 macrophages, regulatory T cells, and interferon gamma+ programmed death-1+ T cells and interferon gamma+ programmed death-1- T cells. Next, we evaluated the presence of these 3 CAF subtypes in surgically resected specimens from patients with advanced esophageal squamous cell carcinoma using RNA in situ hybridization. Analysis of the association between these 3 CAF subtypes and prognosis showed that 2 subtypes (MMP13+ and COL11A1+ myCAFs) were associated with poor prognosis. MMP13+ myCAFs were associated with poorly differentiated infiltration patterns, whereas COL11A1+ myCAFs were associated with lymph node metastasis. These results suggest that future treatments targeting these CAFs and patient stratification based on these CAFs are warranted.

Inflammatory diseases, such as Crohn's disease (CD), are primarily treated with therapies aimed at alleviating inflammation. Notably, biological agents like TNFα inhibitors have transformed the management of these conditions. Previous research has indicated that TNFα inhibitors affect the cells in the lamina propria. However, this study demonstrates that infliximab, a type of TNFα inhibitor, reduces the presence of tertiary lymphoid structures (TLS) and alleviates inflammation of CD by targeting follicular dendritic cells and macrophages within these structures. TLS could also be a potential target for various biological agents used to treat inflammatory diseases beyond CD. Furthermore, our study suggests that the status of TLS may serve as a predictor for the response to TNFα inhibitor treatment. Our research could pave the way for new treatment strategies and the advancement of personalized medicine for inflammatory diseases. ### Competing Interest Statement The authors have declared no competing interest.

Lung squamous cell carcinoma (LSCC) is refractory to various therapies for non-small cell cancer; therefore, new therapeutic approaches are required to improve the prognosis of LSCC. Although immunotherapies targeting B7 family molecules were explored as treatments for several cancer types, the expression and significance of B7-H3 in the tumor microenvironment (TME) and its relationship with other immune checkpoint molecules have not yet been investigated in detail. We used high-throughput quantitative multiplex immunohistochemistry to examine B7-H3 expression in the TME. We investigated the relationship between B7-H3 expression and prognosis as well as changes in the TME with B7-H3 expression using 110 surgically resected pathological specimens retrospectively. We examined the correlation between B7-H3 and programmed cell death-ligand 1 (PD-L1) expression in single cells. High B7-H3 expression in tumor cells was associated with a better prognosis and a significant increase in the number of CD163+PD-L1+ macrophages. Quantitative analysis revealed that there is a positive correlation between B7-H3 and PD-L1 expression in tumor and stromal cells, as well as in intratumoral tumor-infiltrating lymphocytes and tumor-associated macrophages in the same cells. CD68+, CD163+, and CK+ cells with PD-L1+ phenotypes had higher B7-H3 expression compared to PD-L1− cells. Our findings demonstrate a correlation between B7-H3 and PD-L1 expression in the same cells, indicating that therapies targeting B7-H3 could provide additional efficacy in patients refractory to PD-L1-targeting therapies.

Primary vitreoretinal lymphoma (PVRL) is a rare malignant lymphoma subtype with an unfavorable prognosis due to frequent central nervous system (CNS) progression. Thus, identifying factors associated with CNS progression is essential for improving the prognosis of PVRL patients. Accordingly, we conducted a comprehensive genetic analysis using archived vitreous humor samples of 36 PVRL patients diagnosed and treated at our institution and retrospectively examined the relationship between genetic alterations and CNS progression. Whole-exome sequencing (N=2) and amplicon sequencing using a custom panel of 107 lymphomagenesis-related genes (N=34) were performed to assess mutations and copy number alterations. The median number of pathogenic genetic alterations per case was 12 (range, 0-22). Pathogenic genetic alterations of CDKN2A, MYD88, CDKN2B, PRDM1, PIM1, ETV6, CD79B, and IGLL5, as well as aberrant somatic hypermutations, were frequently detected. The frequency of ETV6 loss and PRDM1 alteration (mutation and loss) was 23% and 49%, respectively. Multivariate analysis revealed ETV6 loss (hazard ratio [HR]=3.26, 95% confidence interval [CI]: 1.08-9.85) and PRDM1 alteration (HR=2.52, 95% CI: 1.03-6.16) as candidate risk factors associated with CNS progression of PVRL. Moreover, these two genetic factors defined slow-, intermediate-, and rapid-progression groups (0, 1, and 2 factors, respectively), and the median period to CNS progression differed significantly among them (52 vs. 33 vs. 20 months, respectively). Our findings suggest that genetic factors predict the CNS progression of PVRL effectively, and the genetics-based CNS progression model might lead to stratification of treatment.

INTRODUCTION:Although the diagnostic criteria for atypical femoral fracture (AFF) exclude periprosthetic fractures, reports of periprosthetic femoral fractures with characteristics of AFF are rapidly increasing. In this study, we investigated the frequency and pathogenesis of periprosthetic AFF associated with total knee arthroplasty (TKA) based on a theory of AFF subtypes that divides AFFs into two main types: fragility stress fractures of the bowed femoral shaft in the mid-shaft and "typical" subtrochanteric AFFs due to suppression of bone turnover (e.g., by bisphosphonates).PATIENTS AND METHODS:This multicenter prospective study of AFFs was conducted from 2015 through 2022. Clinical, pathological, and morphological characteristics were investigated in patients with periprosthetic AFFs associated only with non-stem TKA. Then, biomechanical investigation of the periprosthetic AFF was performed by computer tomography-based finite element analysis (CT/FEA) using two models with different load axes to examine how the correction of lower limb alignment by TKA influences the tensile stress distribution of the femur and the location of the AFF.RESULTS:Four of 61 AFFs (6.6%) were identified to be periprosthetic AFF (1 mid-shaft; 3 subtrochanteric). Periprosthetic AFFs had characteristics including mechanical stress due to bowing deformity and potentially suppressed bone turnover due to long-term exposure to specific drugs (e.g., bisphosphonates and glucocorticoids). Although 2 periprosthetic AFFs appeared to involve a bowed femur, one with both of the aforementioned characteristics occurred in the subtrochanteric region, which would be an unusual site for a bowed AFF, and it was demonstrated histologically to have biological activity at the fracture site, suggesting a stress fracture. Furthermore, CT/FEA revealed that tensile stress distribution changed proximally as load axis was shifted laterally according to correction of lower limb alignment by TKA.CONCLUSION:Orthopedic surgeons should recognize the presence of TKA-associated periprosthetic AFF caused by various factors including specific drugs, bowing deformity, and lower limb alignment. X-rays of the full-length femurs should be checked regularly after TKA, especially in patients with bowed femurs or long-term exposure to specific drugs.

Systemic chronic active Epstein-Barr virus disease (sCAEBV) is a rare intractable EBV-positive T-cell or NK-cell lymphoid neoplasm with systemic inflammation. The only curative treatment is allogeneic hematopoietic stem cell transplantation (allo-HSCT). Disease activity defined by multiple inflammatory symptoms is associated with poor survival. In sCAEBV, STAT3 is constitutively activated in EBV-infected T and NK cells and promotes their activation and survival. Ruxolitinib, a Janus kinase 1/2 inhibitor, suppresses the STAT3 activation in vitro, suggesting its clinical potential. We firstly conducted a phase II, multicenter, open-label study to investigate the effects of ruxolitinib on disease activity of sCAEBV. Complete response (CR) and partial response (PR) were defined as complete and partial resolution of disease activity, respectively. Nine patients received ruxolitinib, and seven patients completed the study. The primary endpoint, CR rate (%) 56 days after the administration or at early termination as defined in the protocol, was 22.2% (2/9). No patient showed hematopoietic toxicity nor disease progression. Notably, 71.4% (5/7) of the patients who completed the study were treated at our outpatient clinic. One patient developed a severe adverse event of oral bleeding due to lesion shrinkage during the treatment, and ruxolitinib was discontinued. EBV-DNA levels in whole blood did not change significantly whether the treatment was effective or not. After ruxolitinib treatment, seven patients received allo-HSCT, and five of them achieved CR with undetectable EBV-DNA levels in whole blood. Ruxolitinib is a potent treatment drug that may improve allo-HSCT outcomes by suppressing disease activity of sCAEBV. The trial was registered at UMIN numbered UMIN000035121.

BackgroundEsophageal cancer, particularly esophageal squamous cell carcinoma (ESCC), is a leading cause of cancer-related death and has a poor prognosis. Despite the advancements in multidisciplinary therapies, resistance to conventional treatments warrants the development of novel therapeutic strategies. Ferroptosis, a form of cell death dependent on intracellular iron, has emerged as a potential mechanism for targeting cancer cells resistant to apoptosis. Guanosine triphosphate cyclohydrolase 1 (GCH1) has been identified as a novel antagonist of ferroptosis; however, its role in ESCC remains unclear. This study aimed to investigate the correlation between the expression and accumulation of the lipid peroxidation markers and regulators, including GCH1, in patients with ESCC and examined their prognostic significance. Furthermore, we investigated the relationship between lipid peroxidation regulators and cell death using an in vitro system to establish the basis for new therapeutic strategies.MethodsWe retrospectively analyzed 312 patients with ESCC who underwent radical esophagectomy at the Tokyo Medical and Dental University. Immunohistochemistry was performed to evaluate the expression of lipid peroxidation markers (4-hydroxy-2-nonenal) and regulators (glutathione peroxidase 4 [GPX4], ferroptosis suppressor protein 1 [FSP1], and GCH1). The correlation between these markers, clinicopathological features, and overall survival was assessed. In vitro experiments were performed using KYSE-150 cells to investigate the effects of GCH1 knockdown and overexpression on cell proliferation, cisplatin-induced cell death, and ferroptosis.ResultsLow GCH1 expression was significantly associated with a poor prognosis in patients with ESCC. GCH1 expression correlated with lymph node metastases, vessel invasion, and the pathological tumor stage. In vitro, GCH1-knockdown cells exhibited increased proliferation and resistance to cisplatin-induced cell death, whereas GCH1 overexpression reduced cell proliferation. Simultaneous inhibition of GPX4 and FSP1 induced mild cell death; however, GCH1 knockdown dramatically enhanced ferroptosis, suggesting a synergistic effect.ConclusionGCH1 is a critical prognostic factor for ESCC and plays a significant role in the regulation of cell proliferation and ferroptosis. Targeting GCH1 in combination with GPX4 and FSP1 inhibitors may offer a novel therapeutic strategy for overcoming resistance in ESCC. Further studies are warranted to elucidate the involved molecular mechanisms and validate these findings in vivo.