Impact of fat on the apparent T1 value of the liver: assessment by water-only derived T1 mapping.

OBJECTIVES: To determine the impact of fat on the apparent T1 value of the liver using water-only derived T1 mapping. METHODS: 3-T MRI included 2D Look-Locker T1 mapping and proton density fat fraction (PDFF) mapping. T1 values of the liver were compared among T1 maps obtained by in-phase (IP), opposed-phase (OP), and Dixon water sequences using paired t-test. The correlation between T1 values of the liver on each T1 map and PDFF was assessed using Spearman correlation coefficient. The absolute differences between T1 value of the liver on Dixon water images and that on IP or OP images were also correlated with PDFF. RESULTS: One hundred sixty-two patients (median age, 70 [range, 24-91] years, 90 men) were retrospectively evaluated. The T1 values of the liver on each T1 map were significantly different (p < 0.001). The T1 value of the liver on IP images was significantly negatively correlated with PDFF (r = - 0.438), while the T1 value of the liver on OP images was slightly positively correlated with PDFF (r = 0.164). The T1 value of the liver on Dixon water images was slightly negatively correlated with PDFF (r = - 0.171). The absolute differences between T1 value of the liver on Dixon water images and that on IP or OP images were significantly correlated with PDFF (r = 0.606, 0.722; p < 0.001). CONCLUSION: Fat correction for the apparent T1 value by water-only derived T1 maps will be helpful for accurately evaluating the T1 value of the liver. CLINICAL RELEVANCE STATEMENT: Fat-corrected T1 mapping of the liver with the water component only obtained from the 2D Dixon Look-Locker sequence could be useful for accurately evaluating the T1 value of the liver without the impact of fat in daily clinical practice. KEY POINTS: • The T1 values of the liver on the conventional T1 maps are significantly affected by the presence of fat. • The apparent T1 value of the liver on water-only derived T1 maps would be slightly impacted by the presence of fat. • Fat correction for the apparent T1 values is necessary for the accurate assessment of the T1 values of the liver.

Evaluation of diffusion-weighted magnetic resonance imaging of the rectal cancers: comparison between modified reduced field-of-view single-shot echo-planar imaging with tilted two-dimensional radiofrequency excitation pulses and conventional full field-of-view readout-segmented echo-planar imaging.

PURPOSE: To evaluate the image quality qualitatively and quantitatively, as well as apparent diffusion coefficient (ADC) values of modified reduced field-of-view diffusion-weighted magnetic resonance imaging (MRI) using spatially tailored two-dimensional radiofrequency pulses with tilted excitation plane (tilted r-DWI) based on single-shot echo planar imaging (SS-EPI) compared with full-size field-of-view DWI (f-DWI) using readout segmented (RS)-EPI in patients with rectal cancer. MATERIALS AND METHODS: Twenty-two patients who underwent an MRI for further evaluation of rectal cancer were included in this retrospective study. All MR images were analyzed to compare image quality, lesion conspicuity, and artifacts between f-DWI with RS-EPI and tilted r-DWI with SS-EPI. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and ADC values were also compared. The Wilcoxon signed-rank test or paired t test was performed to compare the qualitative and quantitative assessments. RESULTS: All image quality scores, except aliasing artifacts, were significantly higher (p < 0.01 for all) in tilted r-DWI than f-DWI with RS-EPI. CNR in tilted r-DWI was significantly higher than in f-DWI with RS-EPI (p < 0.01), while SNR was not significantly different. Regarding the ADC values, no significant difference was observed between tilted r-DWI and f-DWI with RS-EPI (p = 0.27). CONCLUSION: Tilted r-DWI provides a better image quality with fewer artifacts and higher rectal lesion conspicuity than f-DWI with RS-EPI, indicating the feasibility of this MR sequence in evaluating rectal cancer in clinical practice.

Three-Dimensional (3D) Breath-Hold Zoomed MR Cholangiopancreatography (MRCP): Evaluation of Additive Value to Conventional 3D Navigator Triggering MRCP in Patients With Branch Duct Intraductal Papillary Mucinous Neoplasms.

BACKGROUND: To resolve drawbacks of navigator triggering (NT) three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP), several approaches were proposed to obtain 3D MRCP within a single breath-hold (BH). However, reduced field-of-view technique in the phase-encoding direction combined with two-dimensional spatially selective radiofrequency excitation pulses has not yet been applied to 3D BH MRCP. PURPOSE: To investigate the feasibility and the complementary value of 3D BH zoomed MRCP to conventional 3D NT MRCP in patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas. STUDY TYPE: Retrospective. POPULATION: A total of 221 patients (116 male and 105 female, median age 73 years) with BD-IPMNs. FIELD STRENGTH/SEQUENCE: 3.0 T/3D turbo spin echo ASSESSMENT: MR images were analyzed by three radiologists (R.M., H.O., M.T., with 1, 13, and 17 years of experience) to compare blurring and motion artifacts, background suppression, visualization of main pancreatic duct (MPD), conspicuity of BD-IPMN, and overall image quality. STATISTICAL TESTS: Wilcoxon-signed rank, Mann-Whitney U, chi-squared or Fisher's exact tests (P < 0.05). RESULTS: Image quality was significantly higher on 3D NT MRCP images than on 3D BH zoomed MRCP (median (interquartile range); background suppression, 4 (4-4) vs. 3 (3-4); visualization of MPD, 4 (3-4) vs. 4 (3-4), conspicuity of BD-IPMN, 4 (3-4) vs. 3 (3-4); and overall image quality, 3 (3-4) vs. 3 (3-3)). However, in 32 (14%) patients, 3D NT MRCP showed a score of 1 or 2 in overall image quality. Regarding the conspicuity of BD-IPMN, a conspicuity score of 1 or 2 was rendered in 31 (14%) patients in 3D NT MRCP group. Conversely, 3D BH zoomed MRCP showed a score of 3 or 4 in 29 (94%) of these 31 patients. DATA CONCLUSION: 3D BH zoomed MRCP plays a complementary role to 3D NT MRCP, and may improve the conspicuity of BD-IPMNs in patients with irregular breathing pattern. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 2.

Current treatment strategies for postoperative intrahepatic bile duct stones in congenital biliary dilatation: a single center retrospective study.

BACKGROUND: Intrahepatic bile duct (IHBD) stones are one of the most common late complications of Roux-en-Y hepaticojejunostomy for congenital biliary dilatation (CBD). We report the current treatment strategies for IHBD stones and their outcomes in our institute. METHODS: Between 1983 and 2021, 117 patients with CBD were surgically treated in our institute. Our treatment strategies included oral ursodeoxycholic acid (UDCA), double-balloon endoscopic retrograde cholangiography (DB-ERC), percutaneous cholangio-drainage (PTCD), and open surgery. A retrospective study was conducted using medical charts. RESULTS: Postoperative IHBD stones were identified in 12 of 117 patients with CBD (10.2%). Five patients received UDCA, and small stones were successfully resolved in two cases. DB-ERC was performed eight times in five patients, but the endoscope could not reach the porta hepatis due to a long jejunal loop in two of five patients. One patient presented with severe acute pancreatitis induced by prolonged DB-ERC. PTCD was performed in three patients, two of whom finally underwent open surgery due to unsuccessful lithotomy. Open surgery was eventually performed in three patients. Lithotomy was performed in one patient; lithotomy with strictureplasty was performed in another patient. The other patient was diagnosed with intrahepatic cholelithiasis with adenocarcinoma. He underwent left lobectomy and died of carcinomatous peritonitis. CONCLUSIONS: Oral UDCA may be effective for small stones. Although DB-ERC should be considered as a first-line interventional therapy for lithotomy, it may not be feasible due to a long jejunal loop, and pancreatitis may occur. Long-term follow-up and early detection and treatment for IHBD stones may yield a good prognosis.

Predictive factors for fundoplication following esophageal atresia repair.

BACKGROUND: One of the most frequent complications after repair of esophageal atresia (EA) is gastroesophageal reflux disease (GERD). Although GERD-associated EA is known to often require anti-reflux surgery, the predicting factors remain unclear. We retrospectively analyzed EA in our institution. METHODS: Of 65 children with EA treated in our hospital from 1995 to 2018, 45 with Gross C type EA, followed for over 1 year, were enrolled in this study. The patients were divided into fundoplication and non-fundoplication groups and compared in terms of their clinical features. RESULTS: The fundoplication and non-fundoplication groups included 13 and 32 cases, respectively. On univariate analysis, gestational age, body weight, prenatal diagnosis, polyhydramnios, re-do surgery, and gap length of the esophagus differed significantly between the groups (P < 0.05). CONCLUSION: Early delivery, low body weight, and a long gap length are, are considered to be risk factors for fundoplication. However, the present study further showed that prenatal diagnosis and polyhydramnios were also significant contributing factors. The presence of a prenatal diagnosis and polyhydramnios may induce preterm delivery, therefore, cases of polyhydramnios due to suspected EA should be managed to prevent early delivery. Better understanding of the postnatal course after surgery is required, especially for prenatal diagnosis cases.

Development of minimally invasive cancer immunotherapy using anti-disialoganglioside GD2 antibody-producing mesenchymal stem cells for a neuroblastoma mouse model.

PURPOSE: Mouse IgG anti-disialoganglioside GD2 antibody-secreting mouse mesenchymal stem cells (anti-GD2-MSCs) were developed, and their anti-tumor effects were validated in an in vivo neuroblastoma mouse model. METHODS: Anti-GD2 antibody constructs were generated, incorporating FLAG-tagged single-chain fragment variables against GD2 fused to a linker sequence, and a fragment of a stationary portion was changed from human IgG to mouse IgG and GFP protein. The construct was lentivirally introduced into mouse MSCs. A syngeneic mouse model was established through the subcutaneous transplantation of a tumor tissue fragment from a TH-MYCN transgenic mouse, and the homing effects of anti-GD2-MSCs were validated by In vivo imaging system imaging. The syngeneic model was divided into three groups according to topical injection materials: anti-GD2-MSCs with IL-2, IL-2, and PBS. The tumors were removed, and natural killer (NK) cells were counted. RESULTS: Anti-GD2-MSCs showed homing effects in syngeneic models. The growth rate of subcutaneous tumors was significantly suppressed by anti-GD2-MSCs with IL-2 (p < 0.05). Subcutaneous tumor immunostaining showed an increased NK cell infiltration in the same group (p < 0.01). CONCLUSION: Anti-GD2-MSCs using mouse IgG showed a homing effect and significant tumor growth suppression in syngeneic models. Anti-GD2-MSC-based cellular immunotherapy could be a novel therapeutic strategy for intractable neuroblastoma.

IL13 and periostin in active fibrogenic areas of the extrahepatic bile ducts in biliary atresia patients.

BACKGROUND: The leading pathology of biliary atresia (BA) is inflammatory and fibrous obstruction of extrahepatic bile duct, but the pathogenesis remains unclear. IL13 is a cytokine associated with allergies and inflammatory fibrosis, and periostin induces fibrogenesis by stimulation with IL13. We analyzed the involvement of IL13 and periostin in inflammatory fibrosis in the extrahepatic bile duct of BA patients. MATERIALS AND METHODS: Surgically resected tissues from the hepatic hilar area of BA patients were immunostained with CD45, α-SMA, IL13 and periostin and statistically analyzed. Fibroblasts from the resected tissue were cultured with recombinant IL13, and periostin production was analyzed by quantitative polymerase chain reaction and Western blotting. RESULTS: IL13 was stained in 93% of large and micro bile ducts, and 92.1% matched with the CD45 location (p = 0.006) around the large bile ducts. Periostin staining correlated with the localization of IL13 and αSMA (p < 0.001) around the large bile ducts. Periostin mRNA and protein were upregulated by IL13 stimulation in cultured fibroblasts. CONCLUSION: IL13 was associated with induced periostin expression by fibroblasts, playing a vital role in the pathogenesis of fibrogenesis around the extrahepatic bile duct in BA.

The synergistic antitumor effect of combination therapy with a MEK inhibitor and YAP inhibitor on pERK-positive neuroblastoma.

BACKGROUND: We previously reported the in vitro and in vivo antitumor effects of trametinib, a MEK inhibitor, on neuroblastoma with MAPK pathway mutations. As we observed eventual resistance to trametinib in our previous study, we evaluated the combination therapy of CA3, a YAP inhibitor, with trametinib, based on a recent report suggesting the potential involvement of YAP in the mechanism underlying the resistance to trametinib in neuroblastoma. METHODS: SK-N-AS cells (a neuroblastoma cell line harboring RAS mutation) were treated with CA3 in vitro and subjected to a viability assay, immunocytochemistry and flow cytometry. Next, we analyzed the in vitro combination effect of CA3 and trametinib using the CompuSyn software program. Finally, we administered CA3, trametinib or both to SK-N-AS xenograft mice for 10 weeks to analyze the combination effect. RESULTS: CA3 inhibited cell proliferation by both cell cycle arrest and apoptosis in vitro. Combination of CA3 and trametinib induced a significant synergistic effect in vitro (Combination Index <1). Regarding the in vivo experiment, combination therapy suppressed tumor growth, and 100% of mice in the combination therapy group survived, whereas the survival rates were 0% in the CA3 group and 33% in the trametinib group. However, despite this promising survival rate in the combination group, the tumors gradually grew after seven weeks with MAPK reactivation. CONCLUSION: Our results indicated that CA3 and trametinib exerted synergistic antitumor effects on neuroblastoma in vitro and in vivo, and CA3 may be a viable option for concomitant drug therapy with trametinib, since it suppressed the resistance to trametinib. However, this combination effect was not sufficient to achieve complete remission. Therefore, we need to adjust the protocol to obtain a better outcome by determining the mechanism underlying regrowth in the future.

Pancreatobiliary Flow Dynamics: Association Between Bile and Pancreatic Juice Evaluated With Cine-Dynamic Magnetic Resonance Cholangiopancreatography Using Spatially Selective Inversion Recovery Pulse.

BACKGROUND: The physiological flow patterns and the reciprocal relationship between pancreatic juice and bile excretion dynamics have not been clearly elucidated by imaging. PURPOSE: To assess the physiological flow patterns of bile and pancreatic juice simultaneously in order to clarify the pancreatobiliary flow dynamics using cine-dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatial selective inversion recovery (IR) pulse. STUDY TYPE: Retrospective. POPULATION: A total of 85 patients with physiologically normal pancreatobiliary flow without ductal dilatation (normal group) and 19 patients with dilated pancreatic duct. FIELD STRENGTH/SEQUENCE: A 3 T, fast spin echo sequence with IR pulse to nullify the signal of static pancreatic juice and bile. ASSESSMENT: The frequency and secretion grade of the antegrade and reverse flow of the pancreatic juice and bile on cine-dynamic MRCP were visually evaluated. Additionally, the reciprocal relationship between pancreatic juice and bile flow was evaluated based on its flow patterns. STATISTICAL TESTS: Spearman's rank correlation coefficient analysis and the Kruskal-Wallis and Mann-Whitney U tests were used. P values of <0.05 were considered to indicate statistical significance. RESULTS: In the normal group, the antegrade pancreatic juice flow and no bile flow pattern was most frequently observed (29%), followed by the no pancreatic juice flow and no bile flow pattern (23%), the antegrade pancreatic juice flow and antegrade bile flow pattern (22%), and the no pancreatic juice flow and reverse bile flow pattern (9%). The flow of the pancreatic juice and bile were synchronized with each other in 47%, while they were not in 53%. In the dilated pancreatic duct group, the mean secretion grade of the antegrade bile and pancreatic juice flow was significantly lower than in the normal group. DATA CONCLUSION: Cine-dynamic MRCP with a spatially selective IR pulse can visualize the variations of the physiological flow patterns of bile and pancreatic juice including 53% of unsynchronized patterns. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 5.

Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Pancreas With Tilted Excitation Plane: A Preliminary Study.

BACKGROUND: Reduced field-of-view diffusion-weighted imaging (rDWI) with tilted two-dimensional radiofrequency (RF) excitation planes has not yet been applied to the imaging of the pancreas although the utility of this technique which allows the acquisition of high-quality images without aliasing artifacts in the phase-encoding direction has been evaluated for brain and spinal cord imaging. PURPOSE: To evaluate the visual image quality of the pancreas by tilting the excitation plane (tilted rDWI) in comparison to conventional DWI (cDWI) and rDWI without using the tilted excitation plane. STUDY TYPE: Retrospective. POPULATION: Thirty-two patients evaluated for suspected pancreatobiliary diseases. FIELD STRENGTH/SEQUENCE: Echo-planar imaging DWI (cDWI, rDWI, and tilted rDWI) acquired at 3 T. ASSESSMENT: Images from each DWI sequence were analyzed by five radiologists to compare image quality (conspicuity of pancreatic edges, interslice signal homogeneity, overall image quality, and conspicuity of focal pancreatic lesions) and artifacts (presence of blurring or ghosting artifacts, susceptibility artifacts, and aliasing artifact). STATISTICAL TESTS: Shapiro-Wilk test was performed to assess whether data were normally distributed. Friedman test followed by Bonferroni-adjusted Wilcoxon signed-rank test for post hoc analysis was performed to compare image quality and artifact scores. RESULTS: The mean scores for conspicuity of pancreatic edges (3.36 vs. 2.37), interslice signal homogeneity (3.14 vs. 2.81), presence of ghosting artifacts (3.32 vs. 2.66), susceptibility artifacts (3.06 vs. 2.30), and aliasing artifacts (3.90 vs. 2.34), and overall image quality (3.49 vs. 2.36) were significantly higher in the tilted rDWI than in the rDWI (P < 0.017 for all parameters). The conspicuity score for focal pancreatic lesions tended to be higher in tilted rDWI than in rDWI (2.44 vs. 2.00, P = 0.07). DATA CONCLUSION: Tilted rDWI had better image quality and reduced artifacts relative to cDWI and rDWI techniques in the pancreas. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 2.

Correlation between pleural tags on CT and visceral pleural invasion of peripheral lung cancer that does not appear touching the pleural surface.

OBJECTIVES: To evaluate the association between a sign and visceral pleural invasion (VPI) of peripheral non-small-cell lung cancer (NSCLC) that does not appear touching the pleural surface. METHODS: A total of 221 consecutive patients with NSCLC that did not appear touching the pleural surface, ≤ 3 cm in solid tumor diameter, and was surgically resected between January 2009 and December 2015 were included. We focused on the flat distortion of the tumor caused by an arch-shaped linear tag between the tumor and the pleura on CT and named it a bridge tag sign. We evaluated the associations between the clinicopathological features of the tumor, including the bridge tag sign, and VPI. We also evaluated the associations between histopathological findings and the bridge tag sign. The utility of the bridge tag sign in the diagnosis of VPI was statistically assessed. RESULTS: The bridge tag sign was observed in 48 (20.8%) patients. VPI was positive in 9 (4.1%) patients; among these, the bridge tag sign was positive in 8 patients. In multivariate analysis, a bridge tag sign was significantly associated with VPI. The bridge tag sign was associated with longer contact length of the pleura with the tumor and trapezoid type pleural retraction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of VPI were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively. CONCLUSIONS: A bridge tag sign on CT might improve the accuracy of the prediction of VPI. KEY POINTS: • We present the bridge tag sign which is defined as a flat distortion of an NSCLC tumor by an arch-shaped linear tag between the tumor and chest wall or interlobar fissure. • The bridge tag sign was an independent predictive factor for visceral pleural invasion. • The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of visceral pleural invasion were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively.

Immunohistochemical staining of phosphorylated-ERK in post-chemotherapeutic samples is a potential predictor of the prognosis of neuroblastoma.

PURPOSE: The majority of relapsed neuroblastomas have mitogen-activated protein kinase (MAPK) pathway activating mutations. We previously showed the in vitro and in vivo anti-tumor effects of MAPK/ERK kinase (MEK) inhibitors in MAPK-activated neuroblastoma. We herein assessed the correlation between MAPK activation and the prognosis in neuroblastoma patients using phosphorylated extra-cellular signal-regulated kinase (pERK) immunohistochemistry to establish the protocol for the clinical administration of MEK inhibitors. METHODS: Neuroblastoma samples from patients treated in our hospital were immunostained with pERK. The clinical outcomes were retrospectively collected from medical records. The correlation between pERK positivity and the prognosis was analyzed. RESULTS: Regarding pre-chemotherapeutic specimens, there were no differences in the pERK status between tumors with a good and bad prognosis in both the nuclei and cytoplasm. Regarding post-chemotherapeutic specimens, one of eight tumors with a good prognosis and four of six tumors with a poor prognosis showed pERK-positive nuclear staining (p = 0.0909) and five of eight tumors with a good prognosis and four of six tumors with a poor prognosis showed pERK-positive cytoplasmic staining (p > 0.9999). CONCLUSION: These findings suggested post-chemotherapeutic-not pre-chemotherapeutic-nuclear pERK-positive neuroblastoma tends to be associated with a poor prognosis and may be a potential therapeutic target for MEK inhibitor treatment.

Influence of fat deposition on T1 mapping of the pancreas: evaluation by dual-flip-angle MR imaging with and without fat suppression.

PURPOSE: To evaluate the influence of fat deposition on T1 relaxation time of pancreatic parenchyma using dual-flip-angle T1 mapping with and without fat suppression. METHODS: Forty-five patients who underwent abdominal MR imaging including T1 mapping with dual-flip-angle method on 3T MRI were included. We measured T1 relaxation time of pancreatic parenchyma on the T1 map images with and without fat suppression. T1 relaxation time of bone marrow was also measured as a reference organ with abundant fat deposition. Fat signal fraction (FSF) was also measured at the same location as T1 map images. Then, the correlation between T1 relaxation time and FSF was assessed. RESULTS: T1 relaxation times of pancreatic parenchyma and bone marrow on the T1 map images without fat suppression showed significantly negative correlation with FSF (pancreas, r = - 0.394, P = 0.007; bone marrow, r = - 0.550, P < 0.001), while there were no significant correlations between them on the T1 map images with fat suppression. On the T1 map images without fat suppression, T1 relaxation times of pancreatic parenchyma as well as bone marrow in patients with FSF ≥ 10% were significantly shorter than those in patients with FSF < 10% (pancreas, P = 0.041; bone marrow, P = 0.005). Conversely, on the T1 map images with fat suppression, no significant differences in T1 relaxation times were found between two groups. CONCLUSION: T1 relaxation time of the pancreas on T1 mapping was influenced by the presence of fat deposition. Therefore, fat suppression technique in T1 mapping will be essential for evaluating T1 relaxation time of pancreatic parenchyma.

Japanese clinical practice guidelines for sacrococcygeal teratoma, 2017.

BACKGROUND: Sacrococcygeal teratoma (SCT) is the most common extragonadal germ cell tumor in neonates and infants. Although most cases of infantile SCT are benign tumors by nature, some develop into extremely large lesions, leading to massive bleeding, high-output heart failure, disseminated intravascular coagulation, and even fatal outcomes during the neonatal period. In addition, some patients may present with tumor recurrence, malignant transformation, long-term sequelae (including bladder and bowel dysfunction) and lower leg palsy during the long-term follow up. SCT, however, is very rare, and there are few opportunities to encounter this disease, therefore general physicians without expert credentials currently lack information relevant to clinical practice. For this reason, the research project committee has compiled guidelines concerning SCT. METHODS: The purpose of these guidelines was to share information concerning the treatment and follow up of infantile SCT. The guidelines were developed using the methodologies in the Medical Information Network Distribution System. A comprehensive search of the English- and Japanese-language articles in PubMed and Ichu-Shi Web identified only case reports or case series, and the recommendations were developed through a process of informal consensus. RESULTS: The clinical questions addressed the risk factors, the efficacy of cesarean section, the initial devascularization of tumor feeding vessels, interventional radiology, recommended clinical studies for follow up and possible long-term complications. CONCLUSIONS: These are the first guidelines for SCT to be established in Japan, and they may have huge clinical value and significance in terms of developing therapeutic strategies and follow up, potentially contributing to the improvement of the prognosis and quality of life of SCT patients.

The roles played by the MYCN, Trk, and ALK genes in neuroblastoma and neural development.

Neuroblastoma is one of the most frequent, yet distinctive and challenging childhood tumors. The uniqueness of this tumor depends on its biological markers, which classify neuroblastomas into favorable and unfavorable, with 5-year survival rates ranging from almost 100-30%. In this review, we focus on some biological factors that play major roles in neuroblastoma: MYCN, Trk, and ALK. The MYCN and Trk family genes have been studied for decades and are known to be crucial for the tumorigenesis and progression of neuroblastoma. ALK gene mutations have been recognized recently to be responsible for familial neuroblastomas. Each factor plays an important role in normal neural development, regulating cell proliferation or differentiation by activating several signaling pathways, and interacting with each other. These factors have been studied not only as prognostic factors, but also as targets of neuroblastoma therapy, and some clinical trials are ongoing. We review the basic aspects of MYCN, Trk, and ALK in both neural development and in neuroblastoma.

Enhanced metastatic growth after local tumor resection in the presence of synchronous metastasis in a mouse allograft model of neuroblastoma.

PURPOSE: We investigated how local tumor resection affects metastatic lesions in neuroblastoma. METHODS: MYCN Tg tumor-derived cells were injected subcutaneously into 129+Ter/SvJcl wild-type mice. First, the frequency of metastasis-bearing mice was investigated immunohistochemically (metastatic ratio) at endpoint or post-injection day (PID) 90. Second, the threshold volume of local tumor in mice bearing microscopic lymph node metastasis (mLNM) was investigated at PID 30. Finally, local tumors were resected after exceeding the threshold. Mice were divided into local tumor resection (Resection) and observation (Observation) groups, and the metastatic ratio and volume of LNM were compared between the groups at endpoint or PID 74. RESULTS: The metastatic ratio without local resection was 88% at PID 78-90. The threshold local tumor volume in the mice with mLNM was 745 mm3 at PID 30, so local tumors were resected after exceeding 700 mm3. The metastatic ratio and LNM volume were significantly greater in the Resection group (n = 16) than in the Observation group (n = 16) (94% vs. 38%, p < 0.001; 2092 ± 2310 vs. 275 ± 218 mm3, p < 0.01; respectively) at PID 50-74. CONCLUSION: Local tumor resection might augment the growth of synchronous microscopic metastases. Our results provide insights into the appropriate timing of local resection for high-risk neuroblastoma.

The tumour suppressor CHD5 forms a NuRD-type chromatin remodelling complex.

Eukaryotic gene expression is developmentally regulated, in part by chromatin remodelling, and its dysregulation has been linked to cancer. CHD5 (chromodomain helicase DNA-binding protein 5) is a tumour suppressor gene (TSG) that maps to a region of consistent deletion on 1p36.31 in neuroblastomas (NBs) and other tumour types. CHD5 encodes a protein with chromatin remodelling, helicase and DNA-binding motifs that is preferentially expressed in neural and testicular tissues. CHD5 is highly homologous to CHD3 and CHD4, which are the core subunits of nucleosome remodelling and deacetylation (NuRD) complexes. To determine if CHD5 forms a similar complex, we performed studies on nuclear extracts from NBLS, SY5Y (both with endogenous CHD5 expression), NLF (CHD5 null) and NLF cells stably transfected with CHD5 cDNA (wild-type and V5-histidine-tagged). Immunoprecipitation (IP) was performed with either CHD5 antibody or antibody to V5/histidine-tagged protein. We identified NuRD components both by GST-FOG1 (Friend Of GATA1) pull-down and by IP. We also performed MS/MS analysis to confirm the presence of CHD5 or other protein components of the NuRD complex, as well as to identify other novel proteins. CHD5 was clearly associated with all canonical NuRD components, including metastasis-associated protein (MTA)1/2, GATA zinc finger domain containing 2A (GATAD2A), histone deacetylase (HDAC)1/2, retinoblastoma-binding protein (RBBP)4/7 and methyl DNA-binding domain protein (MBD)2/3, as determined by Western blotting and MS/MS. Our data suggest CHD5 forms a NuRD complex similar to CHD4. However, CHD5-NuRD may also have unique protein associations that confer functional specificity and may contribute to normal development and to tumour suppression in NB and other cancers.

Surgical intervention and perioperative risk factors of retroperitoneal teratomas in children: a single institution experience.

PURPOSE: Retroperitoneal teratomas (RTs) are rare among germ cell tumors and predominantly occur in infants. RTs are often difficult to manage by perioperative management. In this study, we retrospectively reviewed our series of RTs. METHODS: Seventy patients with germ cell tumors were treated from 1989 to 2015 in our institution. Fourteen patients had RTs (3 boys and 11 girls). The median age at diagnosis was 5.5 months (range 0-64), and three were antenatally diagnosed. RESULTS: All except one patient underwent total tumor excision. They exhibited dense adhesions with major vessels, and ligation of the splenic and gastroduodenal arteries was required in two patients. Injuries of PV and renal artery occurred in two patients. IVC injury in a neonate with a giant mass caused circulatory failure and brain death occurred postoperatively. Other major complications included injury of the diaphragm and bile duct. An infant whose tumor compressed the superior mesenteric artery developed enteritis while waiting for surgery and non-occlusive mesenteric ischemia, resulting in massive intestinal necrosis. The perioperative complication rate was 50 %. CONCLUSION: Surgery for RTs remains challenging, and a preoperative evaluation of the vascular anatomy is crucial due to the high complication rate. Moreover, pre- and intraoperative fluid management is important to avoid any unexpected fatalities.

Retinoic acid-induced CHD5 upregulation and neuronal differentiation of neuroblastoma.

BACKGROUND: Chromodomain-helicase DNA binding protein 5 (CHD5) is an important tumor suppressor gene deleted from 1p36.31 in neuroblastomas (NBs). High CHD5 expression is associated with a favorable prognosis, but deletion or low expression is frequent in high-risk tumors. We explored the role of CHD5 expression in the neuronal differentiation of NB cell lines. METHODS: NB cell lines SH-SY5Y (SY5Y), NGP, SK-N-DZ, IMR5, LAN5, SK-N-FI, NB69 and SH-EP were treated with 1-10 µM 13-cis-retinoic acid (13cRA) for 3-12 days. qRT-PCR and Western blot analyses were performed to measure mRNA and protein expression levels, respectively. Morphological differences were examined by both phase contrast and immunofluorescence studies. RESULTS: Treatment of SY5Y cells with 13cRA caused upregulation of CHD5 expression in a time- and dose-dependent manner (1, 5, or 10 µM for 7 or 12 days) and also induced neuronal differentiation. Furthermore, both NGP and SK-N-DZ cells showed CHD5 upregulation and neuronal differentiation after 13cRA treatment. In contrast, 13cRA treatment of IMR5, LAN5, or SK-N-FI induced neither CHD5 expression nor neuronal differentiation. NB69 cells showed two different morphologies (neuronal and substrate adherent) after 12 days treatment with 10 µM of 13cRA. CHD5 expression was high in the neuronal cells, but low/absent in the flat, substrate adherent cells. Finally, NGF treatment caused upregulation of CHD5 expression and neuronal differentiation in SY5Y cells transfected to express TrkA (SY5Y-TrkA) but not in TrkA-null parental SY5Y cells, and both changes were blocked by a pan-TRK inhibitor. CONCLUSIONS: Treatment with 13cRA induces neuronal differentiation only in NB cells that upregulate CHD5. In addition, NGF induced CHD5 upregulation and neuronal differentiation only in TrkA expressing cells. Together, these results suggest that CHD5 is downstream of TrkA, and CHD5 expression may be crucial for neuronal differentiation induced by either 13cRA or TrkA/NGF signaling.

Stable two- and three-dimensional cholangiocyte culture systems from extrahepatic bile ducts of biliary atresia patients: use of structural and functional bile duct epithelium models for in vitro analyses.

We herein report two- (2D) and three-dimensional (3D) culture methods of cholangiocytes originating from extrahepatic bile ducts of biliary atresia (BA) patients. Cells were stabilized for in vitro analyses, and 3D culture by two different methods showed the structural and functional features of cholangiocytes in the gel scaffold. First, cells were obtained from gallbladder contents or resected tissues of patients at surgery and then cultured in our original conditioned medium with a cocktail of signaling inhibitors that maintains the immaturity and amplification of cells. Cells were immortalized by inducing SV40T and hTERT genes using lentivirus systems. Immunostaining with CK19 and Sox9 antibodies confirmed the cells as cholangiocytes. 3D organoids were formed in Matrigel in two different ways: by forming spheroids or via vertical growth from 2D cell sheets (2 + 1D culture). Organoids generated with both methods showed the uptake and excretion of rhodamine-123, and duct-like structures were also found. Our culture methods are simpler than previously reported methods and still show the structural and functional characteristics of cholangiocytes. Thus, this system is expected to be useful for the in vitro investigation of cholangiocyte damage or regeneration in BA patients.