Parbendazole as a promising drug for inducing differentiation of acute myeloid leukemia cells with various subtypes.

Acute myeloid leukemia (AML) is a malignancy characterized by differentiation arrest of hematopoietic precursor cells. Differentiation therapy is effective for patients with acute promyelocytic leukemia; however, only a few effective differentiation therapies have been established for patients with other AML subtypes. In this study, seven benzimidazole anthelmintics were examined to determine the effects of differentiation on AML cells. The expression of monocyte markers (CD11b and CD14) was elevated after treatment with most benzimidazole anthelmintics. Among these drugs, parbendazole (PBZ) induced AML cell differentiation at low concentration. PBZ induced the monocyte marker expression, KLF4/DPYSL2A gene expression, and apoptosis for 21 AML cell lines with various subtypes and a primary AML sample. Finally, an in vivo analysis using an AML patient-derived xenograft mouse model showed a significant decrease in the chimerism level and prolonged survival in PBZ-treated mice. These findings could lead to a more effective differentiation therapy for AML.

Canonical BAF complex regulates the oncogenic program in human T-cell acute lymphoblastic leukemia.

ABSTRACT: Acute leukemia cells require bone marrow microenvironments, known as niches, which provide leukemic cells with niche factors that are essential for leukemic cell survival and/or proliferation. However, it remains unclear how the dynamics of the leukemic cell-niche interaction are regulated. Using a genome-wide CRISPR screen, we discovered that canonical BRG1/BRM-associated factor (cBAF), a variant of the switch/sucrose nonfermenting chromatin remodeling complex, regulates the migratory response of human T-cell acute lymphoblastic leukemia (T-ALL) cells to a niche factor CXCL12. Mechanistically, cBAF maintains chromatin accessibility and allows RUNX1 to bind to CXCR4 enhancer regions. cBAF inhibition evicts RUNX1 from the genome, resulting in CXCR4 downregulation and impaired migration activity. In addition, cBAF maintains chromatin accessibility preferentially at RUNX1 binding sites, ensuring RUNX1 binding at these sites, and is required for expression of RUNX1-regulated genes, such as CDK6; therefore, cBAF inhibition negatively impacts cell proliferation and profoundly induces apoptosis. This anticancer effect was also confirmed using T-ALL xenograft models, suggesting cBAF as a promising therapeutic target. Thus, we provide novel evidence that cBAF regulates the RUNX1-driven leukemic program and governs migration activity toward CXCL12 and cell-autonomous growth in human T-ALL.

Denosumab-associated Periprosthetic Atypical Femur Fracture: A Case Report.

Introduction: Denosumab is generally used for 5-10 years to treat postmenopausal osteoporosis. Although atypical fractures caused by bisphosphonate use are well known, reports of denosumab-associated femur fractures are rare. Case Report: Herein, a 75-year-old woman suffered an atypical periprosthetic femoral fracture 31 months after receiving denosumab. The fracture occurred transverse to the stem tip with lateral cortical thickening. The patient underwent revision surgery for conversion to a longer cemented stem. The fracture site healed 10 months after revision surgery. Conclusion: As far as we know, there have been no reports of a case on periprosthetic atypical femur fracture associated with denosumab. Our study shows the potential of periprosthetic atypical femoral fractures in patients using denosumab for a long time.

Rupture of External Iliac Artery during Total Hip Arthroplasty after Rotational Acetabular Osteotomy: A Case Report.

Introduction: Total hip arthroplasty (THA) is widely accepted as a safe and effective procedure to relieve hip pain and restore function, but complications can lead to a poor outcome. Although major vascular injuries during THA are rare, when they do occur, massive bleeding may threaten life. Case Report: We describe a case of a 72-year-old woman who underwent THA after rotational acetabular osteotomy (RAO). When the soft tissue in the acetabular fossa was dissected with electrocautery, massive pulsatile bleeding suddenly occurred. A blood transfusion and metal stent graft repair saved her life. We assume that the cause of the arterial injury was a bone defect of the acetabulum and relocation of the external iliac artery after RAO. Conclusion: To avoid arterial injury during THA, pre-operative three-dimensional computed tomographic angiography to locate the intrapelvic vessels around the acetabulum is recommended in cases with complex hip anatomy.

Multi-omics analysis defines highly refractory RAS burdened immature subgroup of infant acute lymphoblastic leukemia.

KMT2A-rearranged infant acute lymphoblastic leukemia (ALL) represents the most refractory type of childhood leukemia. To uncover the molecular heterogeneity of this disease, we perform RNA sequencing, methylation array analysis, whole exome and targeted deep sequencing on 84 infants with KMT2A-rearranged leukemia. Our multi-omics clustering followed by single-sample and single-cell inference of hematopoietic differentiation establishes five robust integrative clusters (ICs) with different master transcription factors, fusion partners and corresponding stages of B-lymphopoietic and early hemato-endothelial development: IRX-type differentiated (IC1), IRX-type undifferentiated (IC2), HOXA-type MLLT1 (IC3), HOXA-type MLLT3 (IC4), and HOXA-type AFF1 (IC5). Importantly, our deep mutational analysis reveals that the number of RAS pathway mutations predicts prognosis and that the most refractory subgroup of IC2 possesses 100% frequency and the heaviest burden of RAS pathway mutations. Our findings highlight the previously under-appreciated intra- and inter-patient heterogeneity of KMT2A-rearranged infant ALL and provide a rationale for the future development of genomics-guided risk stratification and individualized therapy.

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-Prkdcscid ll2rgtm1Sug /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.

The combination of ruxolitinib and Bcl-2/Mcl-1 inhibitors has a synergistic effect on leukemic cells carrying a SPAG9::JAK2 fusion.

JAK2 rearrangements can occur in Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL). Here, we performed functional analysis of the SPAG9::JAK2 fusion, which was identified in a pediatric patient with Ph-like ALL, to establish molecular targeted therapy. Ba/F3 cells expressing SPAG9::JAK2 generated by retroviral transduction (Ba/F3-SPAG9-JAK2), proliferated in the absence of IL-3, and exhibited constitutive phosphorylation of the tyrosine residues in the JAK2 kinase domain of the fusion protein and STAT3/STAT5. Mutation of tyrosine residues in the JAK2 kinase domain (SPAG9::JAK2 mut) abolished IL-3 independence, but had no influence on STAT3/STAT5 phosphorylation levels. Gene expression analysis revealed that Stat1 was significantly upregulated in Ba/F3-SPAG9-JAK2 cells. STAT1 was also phosphorylated in Ba/F3-SPAG9-JAK2 but not SPAG9-JAK2 mut cells, suggesting that STAT1 is key for SPAG9::JAK2-mediated cell proliferation. Consistently, STAT1 induced expression of the anti-apoptotic proteins, BCL-2 and MCL-1, as did SPAG9::JAK2, but not SPAG9::JAK2 mut. Ruxolitinib abrogated Ba/F3-SPAG9-JAK2-mediated proliferation in vitro, but was insufficient in vivo. Venetoclax (a BCL-2 inhibitor) or AZD5991 (an MCL-1 inhibitor) enhanced the effects of ruxolitinib on Ba/F3-SPAG9-JAK2 in vitro. These findings suggest that activation of the JAK2-STAT1-BCL-2/MCL-1 axis contributes to SPAG9::JAK2-related aberrant growth promotion. BCL-2 or MCL-1 inhibition is a potential therapeutic option for B-ALL with SPAG9::JAK2 fusion.

PAX5 alterations in an infant case of KMT2A-rearranged leukemia with lineage switch.

Lineage switch is a rare event at leukemic relapse. While mostly known to occur in KMT2A-rearranged infant leukemia, the underlying mechanism is yet to be depicted. This case report describes a female infant who achieved remission of KMT2A-MLLT3-rearranged acute monocytic leukemia, but 6 months thereafter, relapsed as KMT2A-MLLT3-rearranged acute lymphocytic leukemia. Whole exome sequencing of the bone marrow obtained pre-post lineage switch revealed two somatic mutations of PAX5 in the relapse sample. These two PAX5 alterations were suggested to be loss of function, thus to have played the driver role in the lineage switch from acute monocytic leukemia to acute lymphocytic leukemia.

Improvement of Bone Marrow Necrosis by Tyrosine Kinase Inhibitor Substitution in a Pediatric Patient With Philadelphia Chromosome-positive Acute Lymphoblastic Leukemia.

Bone marrow necrosis (BMN) describes necrosis of the myeloid tissues without cortical bone involvement. Imatinib, a tyrosine kinase inhibitor, can trigger BMN during the treatment of malignant disease. In such cases, it is necessary to reduce imatinib dose or discontinue its administration, which could influence treatment outcomes. Here, we report a 6-year-old boy with Philadelphia chromosome-positive acute lymphoblastic leukemia, who developed BMN in response to imatinib. We replaced imatinib with dasatinib, and necrotic lesions gradually disappeared and were never exacerbated. In Philadelphia chromosome-positive acute lymphoblastic leukemia with BMN, tyrosine kinase inhibitor replacement may allow continued chemotherapy without intensity reduction.

Alteration of the immune environment in bone marrow from children with recurrent B cell precursor acute lymphoblastic leukemia.

Due to the considerable success of cancer immunotherapy for leukemia, the tumor immune environment has become a focus of intense research; however, there are few reports on the dynamics of the tumor immune environment in leukemia. Here, we analyzed the tumor immune environment in pediatric B cell precursor acute lymphoblastic leukemia by analyzing serial bone marrow samples from nine patients with primary and recurrent disease by mass cytometry using 39 immunophenotype markers, and transcriptome analysis. High-dimensional single-cell mass cytometry analysis elucidated a dynamic shift of T cells from naïve to effector subsets, and clarified that, during relapse, the tumor immune environment comprised a T helper 1-polarized immune profile, together with an increased number of effector regulatory T cells. These results were confirmed in a validation cohort using conventional flow cytometry. Furthermore, RNA transcriptome analysis identified the upregulation of immune-related pathways in B cell precursor acute lymphoblastic leukemia cells during relapse, suggesting interaction with the surrounding environment. In conclusion, a tumor immune environment characterized by a T helper 1-polarized immune profile, with an increased number of effector regulatory T cells, could contribute to the pathophysiology of recurrent B cell precursor acute lymphoblastic leukemia. This information could contribute to the development of effective immunotherapeutic approaches against B cell precursor acute lymphoblastic leukemia relapse.

Relationship between Perceived Leg Length Discrepancy at One Month and Preoperative Hip Abductor Muscle Elasticity in Patients after Total Hip Arthroplasty.

OBJECTIVE: Preoperative factors related to perceived leg length discrepancy (PLLD) after total hip arthroplasty (THA) are not well studied. This study aimed to examine the preoperative factors, including hip abductor modulus, related to PLLD one month after THA. METHODS: The study included 73 patients diagnosed with osteoarthritis secondary to developmental dysplasia of the hip and a posterior approach to surgery. Multiple logistic regression analysis was performed using the presence or absence of PLLD as the dependent variable and preoperative hip abductor's modulus of elasticity, pain, hip abduction range of motion, hip abductor muscle strength and pelvic obliquity as the independent variable. Additionally, receiver operating characteristic curves were used for the extracted variables for calculating the cutoffs, sensitivity, specificity and area under the curve (AUC) to determine the presence or absence of PLLD. The significance level was set at p<0.05. RESULTS: The hip abductor modulus (odds ratio=1.13; 95% confidence interval=1.06-1.21; p<0.001) was selected as a preoperative factor. The cutoff value to determine the presence or absence of a PLLD was 16.32 kPa. The sensitivity and specificity were 81.8% and 72.5%, respectively, and the AUC was 0.8137. CONCLUSION: The hip abductor muscle elastic modulus affected PLLD one month after THA. If the preoperative hip abductor elastic modulus is higher than the cutoff value, it may affect the appearance of PLLD at one month postoperatively.

Intracranial Growing Teratoma Syndrome With Intraventricular Lipid Accumulation.

Growing teratoma syndrome is a well-recognized condition associated with both intracranial and extracranial nongerminomatous germ cell tumors (NGGCTs), which mostly manifest as rapid growth of cystic and solid components during or within several months after treatment. Here, we report a patient with NGGCT who experienced slow growth of intracranial growing teratoma syndrome with intraventricular lipid accumulation over 10 years without any clinical symptoms. Considering the clinicopathologic heterogeneity of this syndrome, long-term clinical and radiologic follow-up is required for all patients with intracranial NGGCT.

[Malignant gastrointestinal lymphoma with cicatricial stenosis after complete response to chemotherapy].

A 75-year-old woman presented complaining of anorexia. A malignant gastrointestinal lymphoma was diagnosed, and chemotherapy was initiated. After 2 months, she developed vomiting. Computed tomography (CT) revealed thickening of the jejunal wall and dilatation of the intestine proximal to that area. Positron emission tomography-CT showed no uptake. Small bowel stenosis due to cicatricial stenosis after chemotherapy was suspected. Laparoscopic partial resection of the stenotic small bowel segment was performed. Histopathologically, only granulation tissue was seen with no evidence of tumor. Occasionally, cicatricial stenosis can develop after chemotherapy for malignant gastrointestinal lymphoma. Therefore, this condition must be considered an important complication of treatment for this disease.

Comparison of laparoscopic percutaneous extraperitoneal closure versus conventional herniotomy in extremely low birth weight infants.

PURPOSE: Laparoscopic percutaneous extraperitoneal closure (LPEC) has become routine for repairing pediatric inguinal hernia (IH). Reports on the effective repair of IH in challenging cases, such as extremely low birth weight infants (ELBWI) who become symptomatic soon after birth and have surgery before 1 year of age, are rare; and conventional herniotomy (CH) in ELBWI requires extensive experience of neonatal surgery. We compared LPEC with CH for treating ELBWI with IH. METHODS: Consecutive ELBWI with IH treated by either LPEC (n = 17) or CH (n = 22) before 1 year of age between 2012 and 2017 were reviewed. LPEC were performed by consultant pediatric surgeons (CPS; n = 3) with experience of at least 200 cases each. In CH, 11 cases were treated by CPS and 11 by CPS-supervised surgical trainees. RESULTS: There were no intraoperative complications. Operative time and anesthesia time for bilateral IH repairs were both shorter in LPEC. Postoperative sequelae were recurrence (LPEC; n = 1; repaired by redo LPEC 2 months after the initial repair) and intravenous rehydration (CH; n = 1; for persistent post-anesthetic vomiting). Recovery was unremarkable in all cases without additional analgesia. CONCLUSION: LPEC would appear to be a viable option for treating IH in ELBWI, especially bilateral cases.

Cytomegalovirus infection in ulcerative colitis assessed by quantitative polymerase chain reaction: risk factors and effects of immunosuppressants.

We investigated the risk factors of and appropriate treatment for cytomegalovirus colitis in patients with ulcerative colitis, using quantitative polymerase chain reaction analysis to detect cytomegalovirus in the colonic mucosa. Between February 2013 and January 2017, patients with exacerbated ulcerative colitis who were admitted to our hospital were consecutively enrolled in this retrospective, single-center study. Patients were evaluated for cytomegalovirus using serology (antigenemia) and quantitative polymerase chain reaction analyses of the colonic mucosa, which were sampled during colonoscopy. Of 86 patients, 26 (30.2%) had positive quantitative polymerase chain reaction results for cytomegalovirus; only 4 were also positive for antigenemia. The ages of the cytomegalovirus DNA-positive patients were significantly higher than those of negative patients (p = 0.002). The mean endoscopic score of cytomegalovirus DNA-positive patients was significantly higher than that of cytomegalovirus DNA-negative patients. Treatment with combined immunosuppressants was associated with an increased risk of cytomegalovirus. Fourteen of 15 (93.3%) cytomegalovirus DNA-positive patients who were negative for antigenemia showed a clinical response to treatment with additional oral tacrolimus, without ganciclovir. cytomegalovirus reactivation in active ulcerative colitis is associated with age and combined immunosuppressant therapy. Because additional treatment with tacrolimus was effective, patients who are negative for antigenemia and cytomegalovirus DNA-positive colonic mucosa may recover without antiviral therapy.

Sudden spinal hemorrhage in a pediatric case with total body irradiation-induced cavernous hemangioma.

Compared to cerebral radiation-induced cavernous hemangiomas (RICHs), little is known about intraspinal RICHs. A 13-year-old male suddenly developed symptomatic spinal hemorrhage eight years after hematopoietic stem cell transplantation using a total body irradiation (TBI) based myeloablative regimen. A solitary small hemangioma was detected on follow-up T2 star weighted magnetic resonance imaging of the spine. His neurological symptoms gradually improved with supportive treatment and rehabilitation, although he experienced rebleeding 2 years later. Intraspinal RICH is very rare but should be recognized as a possible late adverse effect in pediatric patients who received TBI.