Wiley Acta Medica Okayama 1320-5463 2021 2021 Investigation of the molecular causes underlying physical abnormalities in Diamond‐Blackfan anemia patients with RPL5 haploinsufficiency 1 11 EN Yuko Fukui Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Satoru Hayano Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Noriaki Kawanabe Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Ziyi Wang Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Akira Shimada Department of Pediatric Hematology/Oncology Okayama University Hospital Megumu K. Saito Department of Clinical Application, Center for iPS Cell Research and Application Kyoto University Isao Asaka Department of Fundamental Cell Technology, Center for iPS Cell Research and Application Kyoto University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Diamond-Blackfan anemia (DBA) is a genetic disorder caused by mutations in genes encoding ribosomal proteins and characterized by erythroid aplasia and various physical abnormalities. Although accumulating evidence suggests that defective ribosome biogenesis leads to p53-mediated apoptosis in erythroid progenitor cells, little is known regarding the underlying causes of the physical abnormalities. In this study, we established induced pluripotent stem cells from a DBA patient with RPL5 haploinsufficiency. These cells retained the ability to differentiate into osteoblasts and chondrocytes. However, RPL5 haploinsufficiency impaired the production of mucins and increased apoptosis in differentiated chondrocytes. Increased expression of the pro-apoptotic genes BAX and CASP9 further indicated that RPL5 haploinsufficiency triggered p53-mediated apoptosis in chondrocytes. MDM2, the primary negative regulator of p53, plays a crucial role in erythroid aplasia in DBA patient. We found the phosphorylation level of MDM2 was significantly decreased in RPL5 haploinsufficient chondrocytes. In stark contrast, we found no evidence that RPL5 haploinsufficiency impaired osteogenesis. Collectively, our data support a model in which RPL5 haploinsufficiency specifically induces p53-mediated apoptosis in chondrocytes through MDM2 inhibition, which leads to physical abnormalities in DBA patients. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 24681245 2021 Profile of down syndrome–associated malignancies: Epidemiology, clinical features and therapeutic aspects EN Akira Shimada Department of Pediatric Hematology, Okayama University Hospital Down syndrome (DS) is a congenital chromosomal abnormality caused by the presence of all or part of a third copy of chromosome 21 (+21). DS is frequently complicated by congenital heart or digestive tract diseases at birth. DS patients are prone to infections and have mental retardation, with dementia such as Alzheimer's disease showing in later life. Furthermore, malignancies with specific characteristics are also highly reported in DS patients compared with non-DS patients. Therefore, DS is believed to be a cancer predisposition syndrome due to the chromosomal instability. Acute myeloid leukemia (AML) and especially acute megakaryoblastic leukemia (AMKL) by French-American-British (FAB) classification are the most frequent hematological malignancies in DS patients, occurring at a rate that is 500 times higher than that in non-DS patients. Interestingly, transient abnormal myelopoiesis (TAM) is observed in approximately 10% of DS neonates with GATA1 mutations, and most TAM patients are asymptomatic and show spontaneous regression; however, about 10%–20% of TAM cases are fatal because of complications such as fetal effusion, liver fibrosis, and other complications.Acute lymphoblastic leukemia (ALL) is also associated with DS, occurring at a rate that is 20 times higher than that in non-DS patients. Furthermore, the prognosis of DS-ALL patients is poorer than that of non-DS-ALL patients. A recent genetic analysis revealed that more than half of DS-ALL cases have a mutation in the CRLF2–JAK pathway, indicating that JAK inhibitors might have a limited effect for DS-ALL patients.Notably, solid tumors such as neuroblastoma, Wilms tumor, and brain tumor, which are frequently observed in non-DS children, are rarely reported in DS children. The reason remains unknown, but it may be because of the triplication of the Down syndrome critical region 1 (DSCR1) gene on chromosome 21. In adult patients with DS, the expected age-adjusted incidence rates of solid tumors are low compared with age-matched euploid cohorts for most cancers except for testicular cancer. Although the average life expectancy of patients with DS will increase with advances in healthcare, the detailed health problems including cancer rates in older DS patients remain unknown. Therefore, these issues will be needed to be addressed in future studies. No potential conflict of interest relevant to this article was reported.

Spandidos Publications Acta Medica Okayama 2049-9434 13 5 2020 Panel‑based next‑generation sequencing facilitates the characterization of childhood acute myeloid leukemia in clinical settings 46 EN Hisashi Ishida Department of Pediatrics/Pediatric Hematology and Oncology, Okayama University Hospital Akihiro Iguchi Department of Pediatrics, Hokkaido University Hospital Michinori Aoe Division of Medical Support, Okayama University Hospital Ritsuo Nishiuchi Department of Pediatrics, Kochi Health Sciences Center Takehiro Matsubara Division of Biobank, Center for Comprehensive Genomic Medicine, Okayama University Hospital Dai Keino Department of Pediatrics, St. Marianna University School of Medicine Hospital Masashi Sanada Clinical Research Center, National Hospital Organization Nagoya Medical Center Akira Shimada Department of Pediatrics/Pediatric Hematology and Oncology, Okayama University Hospital Acute myeloid leukemia (AML) accounts for ~20% of pediatric leukemia cases. The prognosis of pediatric AML has been improved in recent decades, but it trails that of most other types of pediatric cancer, with mortality rates of 30‑40%. Consequently, newer more targeted drugs are required for incorporation into treatment plans. These newer drugs selectively target AML cells with specific gene alterations. However, there are significant differences in genetic alterations between adult and pediatric patients with AML. In the present study, inexpensive and rapid next‑generation sequencing (NGS) of >150 cancer‑related genes was performed for matched diagnostic, remission and relapse (if any) samples from 27 pediatric patients with AML. In this analysis, seven genes were recurrently mutated. KRAS was mutated in seven patients, NRAS was mutated in three patients, and KIT, GATA1, WT1, PTPN11, JAK3 and FLT3 were each mutated in two patients. Among patients with relapsed AML, six harbored KRAS mutations at diagnosis; however, four of these patients lost these mutations at relapse. Additionally, two genetic alterations (FLT3‑ITD and TP53 alterations) were detected among patients who eventually relapsed, and these mutations are reported to be adverse prognostic factors for adult patients with AML. This panel‑based, targeted sequencing approach may be useful in determining the genetic background of pediatric AML and improving the prediction of treatment response and detection of potentially targetable gene alterations. RAS pathway mutations were highly unstable at relapse; therefore, these mutations should be chosen as a target with caution. Incorporating this panel‑based NGS approach into the clinical setting may allow for a patient‑oriented strategy of precision treatment for childhood AML. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 74 6 2020 Delayed Methotrexate Elimination after Administration of a Medium Dose of Methotrexate in a Patient with Genetic Variants Associated with Methotrexate Clearance 545 550 EN Yasuhisa Tatebe Department of Pharmacy, Okayama University Hospital Kiichiro Kanamitsu Department of pediatrics, Okayama University Hospital Hirotaka Kanzaki Department of Pharmacy, Okayama University Hospital Hisashi Ishida Department of pediatrics, Okayama University Hospital Kaori Fujiwara Department of pediatrics, Okayama University Hospital Kana Washio Department of pediatrics, Okayama University Hospital Yoshihisa Kitamura Department of Pharmacy, Okayama University Hospital Toshiaki Sendo Department of Pharmacy, Okayama University Hospital Akira Shimada Department of pediatrics, Okayama University Hospital Hirokazu Tsukahara Department of pediatrics, Okayama University Hospital Case Report 10.18926/AMO/61215 Polymorphisms in methotrexate transporter pathways have been associated with methotrexate toxicities and clearance. Recent genome-wide association studies have revealed that the SLCO1B1 T521C variant is associated with methotrexate elimination. We present a case of a pediatric patient with acute lymphoblastic leukemia who suffered from persistently high plasma methotrexate concentrations and acute kidney injuries after the admin-istration of a medium dose of methotrexate. Subsequent genetic analysis showed that he was a carrier of dys-functional genetic variants associated with methotrexate clearance. This case highlights that polymorphisms of methotrexate transporter pathways can adversely affect methotrexate elimination in a clinically significant manner. No potential conflict of interest relevant to this article was reported.

Lippincott, Williams & Wilkins Acta Medica Okayama 0025-7974 99 38 2020 Pediatric growing teratoma syndrome of the ovary A case report and review of the literature e22297 EN Takanori Oyama Department of Pediatric Surgery,Okayama University Hospital Takuo Noda Department of Pediatric Surgery,Okayama University Hospital Kana Washio Department of Pediatrics, Okayama University Hospital Akira Shimada Department of Pediatrics, Okayama University Hospital Rationale: </br> Growing teratoma syndrome is defined as an increase in tumor size during or after systemic chemotherapy for germ cell tumors. These cases involve normal tumor maker levels and histological features of only mature teratoma. We report a rare case of an ovarian immature teratoma in a Japanese child that was diagnosed as growing teratoma syndrome.</br> Patient concerns: </br> A 12-year-old girl presented a painful abdominal mass. She underwent left salpingo-oophorectomy for grade 1 immature teratoma in the left ovary. She did not undergo additional chemotherapy or radiotherapy. Four months later, she presented with grade 3 immature teratoma disseminated into the abdomen and pelvis. Chemotherapy resulted in the tumor maker levels returning to their normal ranges, although the tumors had grown slightly.</br> Diagnosis: </br> The specimens resected by laparotomy after the chemotherapy consisted of mature tissue predominantly, although primitive neuroepithelium was observed in a small part of the specimen. The pathological diagnosis was grade 1 immature teratoma, notwithstanding the clinical diagnosis was growing teratoma syndrome based on the clinical features and pathogenesis.</br> Interventions: </br> Laparotomy was performed at 7 months after the first operation, with resection of various tumors as well as the rectum, sigmoid colon, residual left fallopian duct, and a small part of the ileum and omentum. Some small tumors at the parietal peritoneum were ablated, although many tiny tumors around the uterus were left untreated.</br> Outcomes: </br> The patient has been free from recurrence for 5 years.</br> Lessons: </br> Growing teratoma syndrome can develop in children, and their tumor size is comparable to that in adolescents and adults. Furthermore, development of growing teratoma syndrome from a primary germ cell tumor is presumably faster in children than in adolescents and adults. Complete resection of all growing teratoma tissue is recommended, although fertility-sparing surgery should be considered when possible. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 71 3 2017 A Case of Refractory Langerhans Cell Histiocytosis Complicated with Hemophagocytic Lymphohistiocytosis Rescued by Cord Blood Transplantation with Reduced-intensity Conditioning 249 254 EN Kana Washio Department of Pediatrics, Okayama University Hospital Michiko Muraoka Department of Pediatrics, National Hospital Organization Fukuyama Medical Center Kiichiro Kanamitsu Department of Pediatrics, Okayama University Hospital Megumi Oda Department of Pediatrics, Okayama University Hospital Akira Shimada Department of Pediatrics, Okayama University Hospital Case Report 10.18926/AMO/55208 　We diagnosed a female infant with Langerhans cell histiocytosis (LCH) who was refractory to conventional chemotherapy. She showed refractory inflammation that was complicated with hemophagocytic lymphohistiocytosis (HLH) during LCH chemotherapy; therefore, we changed the protocol to HLH2004 (dexamethasone, cyclosporine A and VP16). However, there were no signs of hematological recovery. We therefore performed cord blood transplantation with reduced-intensity conditioning, and she achieved complete remission for over 2 years. As salvage therapy for refractory LCH, hematopoietic stem cell transplantation may be a good therapeutic choice, especially when LCH is complicated with HLH. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 71 1 2017 Positive Minimal Residual Disease of FLT3-ITD before Hematopoietic Stem Cell Transplantation Resulted in a Poor Prognosis of an Acute Myeloid Leukemia 79 83 EN Yuka Iwasaki Department of Pediatrics, Kochi Health Sciences Center Rituo Nishiuchi Department of Pediatrics, Kochi Health Sciences Center Michinori Aoe Division of Medical Support, cDepartment of Pediatrics, Okayama University Hospital Takahide Takahashi Division of Medical Support, cDepartment of Pediatrics, Okayama University Hospital Hirokazu Watanabe Department of Pediatrics, Kochi Health Sciences Center Chiho Tokorotani Department of Pediatrics, Kochi Health Sciences Center Kiyoshi Kikkawa Department of Pediatrics, Kochi Health Sciences Center Akira Shimada Department of Pediatrics, Okayama University Hospital Case Report 10.18926/AMO/54829 Acute myeloid leukemia (AML) patients with fms-related tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) often have a poor prognosis, even after hematopoietic stem cell transplantation (HSCT). We report a case of AML with FLT3-ITD identified upon initial diagnosis, who received HSCT at complete remission after 3 consecutive chemotherapies. However, the patient relapsed when the same FLT3-ITD clone emerged, and finally died. Retrospective analysis revealed an allelic ratio of FLT3-ITD/wild type of 1.1 and 0.0096 upon initial diagnosis and before HSCT, respectively. The detection of any minimal residual FLT3-ITD clone before HSCT is useful in the treatment of AML with FLT3-ITD. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 6 2016 Two Relapsed Stage III Childhood Anaplastic Large Cell Lymphoma Patients with NPM-ALK Fusion in Bone Marrow from Initial Diagnosis 503 506 EN Yui Kanazawa Department of aPediatrics, Okayama University Hospital Yuka Yamashita Clinical Research Center, Nagoya Medical Center Mitsuhiro Fujiwara Department of Pediatrics, Kurashiki Central Hospital Michiko Muraoka Department of aPediatrics, Okayama University Hospital Kana Washio Department of aPediatrics, Okayama University Hospital Kiichiro Kanamitsu Department of aPediatrics, Okayama University Hospital Hisashi Ishida Department of aPediatrics, Okayama University Hospital Takae Nakano Department of aPediatrics, Okayama University Hospital Miho Yamada Clinical Research Center, Nagoya Medical Center Keizo Horibe Clinical Research Center, Nagoya Medical Center Takehiro Tanaka Department of Pathology, Okayama University Hospital Tadashi Yoshino Department of Pathology, Okayama University Hospital Akira Shimada Department of aPediatrics, Okayama University Hospital Case Report 10.18926/AMO/54815 Childhood anaplastic large cell lymphoma (ALCL) accounts for approx. 10–30 of cases of non-Hodgkin lymphoma, and the ALCL99 study reported 60–75 disease-free survival; however, a relatively high relapse rate was observed (25–30 ). We report 2 patients with Stage III ALCL who relapsed 6–18 months after the end of ALCL99 chemotherapy. A retrospective molecular analysis identified the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) fusion gene in the first diagnostic bone marrow samples taken from both patients. However, antibodies against the ALK protein appeared to be relatively low in the serum of both patients (×100 and ×750). An increase in chemotherapy intensity may be beneficial if Stage III ALCL patients are shown to be NPM-ALK chimera-positive in the first diagnostic bone marrow sample. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 68 2 2014 Detection of RBM15-MKL1 Fusion Was Useful for Diagnosis and Monitoring of Minimal Residual Disease in Infant Acute Megakaryoblastic Leukemia 119 123 EN Akiko Takeda Akira Shimada Kazuko Hamamoto Syuuji Yoshino Tomoko Nagai Yousuke Fujii Mutsuko Yamada Yoshimi Nakamura Toshiyuki Watanabe Yuki Watanabe Yuko Yamamoto Kanae Sakakibara Megumi Oda Tsuneo Morishima Case Report 10.18926/AMO/52408 Acute megakaryocytic leukemia (AMKL) with t(1;22)(p13;q13) is a distinct category of myeloid leukemia by WHO classification and mainly reported in infants and young children. Accurate diagnosis of this type of AMKL can be difficult, because a subset of patients have a bone marrow (BM) blast percentage of less than 20% due to BM fibrosis. Therefore, it is possible that past studies have underestimated this type of AMKL. We present here the case of a 4-month-old female AMKL patient who was diagnosed by presence of the RBM15-MKL1 (OTT-MAL) fusion transcript by RT-PCR. In addition, we monitored RBM15-MKL1 fusion at several time points as a marker of minimal residual disease (MRD), and found that it was continuously negative after the first induction chemotherapy even by nested RT-PCR. Detection of the RBM15-MKL1 fusion transcript thus seems to be useful for accurate diagnosis of AMKL with t(1;22)(p13;q13). We recommend that the RBM15-MKL1 fusion transcript be analyzed for all suspected AMKL in infants and young children. Furthermore, monitoring of MRD using this fusion transcript would be useful in treatment of AMKL with t(1;22)(p13;q13). No potential conflict of interest relevant to this article was reported.