Mitochondrial glutamate transporter SLC25A22 uni-directionally export glutamate for metabolic rewiring in radioresistant glioblastoma.

Glioblastoma Multiforme (GBM) is a malignant primary brain tumor. Radiotherapy, one of the standard treatments for GBM patients, could induce GBM radioresistance via rewiring cellular metabolism. However, the precise mechanism attributing to GBM radioresistance or targeting strategies to overcome GBM radioresistance are lacking. Here, we demonstrate that SLC25A22, a mitochondrial bi-directional glutamate transporter, is upregulated and showed uni-directionality from mitochondria to cytosol in radioresistant GBM cells, resulting in accumulating cytosolic glutamate. However, mitochondrial glutaminolysis-mediated TCA cycle metabolites and OCR are maintained constantly. The accumulated cytosolic glutamate enhances the glutathione (GSH) production and proline synthesis in radioresistant GBM cells. Increased GSH protects cells against ionizing radiation (IR)-induced reactive oxygen species (ROS) whereas increased proline, a rate-limiting substrate for collagen biosynthesis, induces extracellular matrix (ECM) remodeling, leading to GBM invasive phenotypes. Finally, we discover that genetic inhibition of SLC25A22 using miR-184 mimic decreases GBM radioresistance and aggressiveness both in vitro and in vivo. Collectively, our study suggests that SLC25A22 upregulation confers GBM radioresistance by rewiring glutamate metabolism, and SLC25A22 could be a significant therapeutic target to overcome GBM radioresistance.

DGKB mediates radioresistance by regulating DGAT1-dependent lipotoxicity in glioblastoma.

Glioblastoma (GBM) currently has a dismal prognosis. GBM cells that survive radiotherapy contribute to tumor progression and recurrence with metabolic advantages. Here, we show that diacylglycerol kinase B (DGKB), a regulator of the intracellular concentration of diacylglycerol (DAG), is significantly downregulated in radioresistant GBM cells. The downregulation of DGKB increases DAG accumulation and decreases fatty acid oxidation, contributing to radioresistance by reducing mitochondrial lipotoxicity. Diacylglycerol acyltransferase 1 (DGAT1), which catalyzes the formation of triglycerides from DAG, is increased after ionizing radiation. Genetic inhibition of DGAT1 using short hairpin RNA (shRNA) or microRNA-3918 (miR-3918) mimic suppresses radioresistance. We discover that cladribine, a clinical drug, activates DGKB, inhibits DGAT1, and sensitizes GBM cells to radiotherapy in vitro and in vivo. Together, our study demonstrates that DGKB downregulation and DGAT1 upregulation confer radioresistance by reducing mitochondrial lipotoxicity and suggests DGKB and DGAT1 as therapeutic targets to overcome GBM radioresistance.

Stereotactic body radiotherapy using helical tomotherapy for hepatocellular carcinoma: clinical outcome and dosimetric comparison of Hi-ART vs. Radixact.

Background: Helical tomotherapy (HT), a unique rotational dose delivery machine, has been updated from Hi-ART to Radixact. We retrospectively evaluated the treatment outcomes of stereotactic body radiotherapy (SBRT) using HT for hepatocellular carcinoma (HCC) and compared the dosimetric details of Hi-ART and Radixact. Methods: Between April 2014 and November 2020, 28 patients with HCC were treated with SBRT using HT for a cure at Soonchunhyang University College of Medicine, Bucheon. According to the Barcelona Clinic Liver Cancer classification, 9 patients had stage 0 disease, 12 had stage A, 4 had stage B, and 3 had stage C. The tumor size ranged from 1 cm to 8 cm (median, 2 cm). The SBRT dose ranged from 40 to 60 Gy (median, 48 Gy) with 4 fractions. Twenty-three patients were treated with Hi-ART and 5 patients were treated with Radixact. To compare the dosimetric parameters between Hi-ART and Radixact, we created treatment plans with the same constraints, pitch, modulation factor, and field width for the same patient in pairs. Results: The median follow-up time from the date of SBRT administration was 24 months (range, 3-67 months). The local failure-free survival and intrahepatic failure-free survival rates were 96% and 58% at 1 year, 84% and 36% at 2 years, and 76% and 18% at 3 years, respectively. The overall survival rate was 93% at 1 year, 93% at 2 years, and 53% at 3 years, respectively. When the paired treatment plans were reviewed, the beam-on time and intermediate dose-spillage were found to be significantly reduced in Radixact than Hi-ART (P<0.001). With regard to normal organ sparing, the irradiated dose to the total liver, normal liver, heart, and kidney was significantly lower with Radixact (P<0.001). Conclusions: SBRT using HT for HCC showed favorable treatment outcomes. Radixact, the latest version, physically improved treatment efficiency by reducing treatment time and provided better organ sparing than Hi-ART.

Treatment outcomes of helical tomotherapy for hepatocellular carcinoma in terms of intermediate-dose spillage.

BACKGROUND: Although helical tomotherapy (HT) tends to increase intermediate-dose spillage by increasing of low-dose region, this has not been fully determined in the clinical setting. Therefore, we investigated treatment outcomes of HT for hepatocellular carcinoma (HCC) with respect to intermediate-dose spillage. METHODS: We retrospectively reviewed 20 HCC patients, who received high-dose radiotherapy (RT) using HT with radical intent between April 2014 and September 2017. In accordance with the Barcelona Clinic Liver Cancer (BCLC) classification, stage was 0 in 7 patients, A in 3 patients, B in 5 patients, and C in 5 patients. Baseline Child-Pugh class was A in 18 patients and B in 2 patients. The median tumor size was 2.5 cm (range, 1-11 cm). Helical intensity-modulated radiotherapy (IMRT) technique was applied in all patients: among these, 13 patients were treated with stereotactic body radiotherapy (SBRT). The median fraction size was 12 Gy (range, 2-15 Gy), and the median total dose was 50 Gy (range, 44-60 Gy). Intermediate-dose spillage was assessed by the Radiation Therapy Oncology Group recommendation from 22 HT planning data, as follows: R50% means the ratio of the 50% prescription isodose volume to the planning target volume (PTV). RESULTS: The median follow-up period after HT was 22 months. The local progression-free survival (LPFS) and progression-free survival (PFS) rates were 89% and 59% at 1 year, and 82% and 30% at 2 years, respectively. The overall survival rate was 100% at 1 year and 85% at 2 years, respectively. In terms of intermediate-dose spillage, minor or major deviations were noted in the R50% of 20 HT plans (91%). However, 1 patient (5%) experienced classic radiation-induced liver disease, and severe toxicity ≥ grade 3 was not reported. CONCLUSIONS: Although HT for HCC tends to increase intermediate-dose spillage, the treatment results were favorable with that reported in other published studies.

Refractive corneal inlay for presbyopia in emmetropic patients in Asia: 6-month clinical outcomes.

BACKGROUND: To evaluate the 6-month clinical outcomes of Flexivue Microlens refractive corneal inlay in emmetropic patients in Asia for the surgical compensation of presbyopia. METHODS: In this retrospective study, corneal inlay implantation was done using a femtosecond laser. The follow-up period was 6 months. Near/intermediate/distant visual acuities, refraction, keratometry, defocus curve, wavefront aberrations, contrast sensitivity, Scheimpflug corneal scanning, endothelial cell density, dry eye test, confocal microscopy scanning, and patient questionnaires were evaluated. RESULTS: The inlay implantation was performed in 21 eyes from June 2015 to April 2017. 6 months after surgery, the uncorrected near visual acuity of the operated eyes increased significantly from 0.55 ± 0.22 logMAR preoperatively to 0.25 ± 0.15 logMAR (p < 0.05) but mean bilateral uncorrected distant visual acuity did not change significantly (p = 0.90). Total higher-order aberration and spherical aberration increased, and the contrast sensitivity of the operated eyes decreased. Endothelial cell density and central corneal thickness did not change from preoperative values. Patient satisfaction for near vision was increased 6 months after implantation, and 50.0% of patients were independent of near spectacles. Explantation was done in 2 cases. CONCLUSION: The Flexivue Microlens refractive corneal inlay was effective for improving near visual acuity at 6 months follow-up But proportion of spectacle independency and patient satisfaction were lower in this Korean population than in previous reports. Further study with a longer follow-up period is needed.

RNF138-mediated ubiquitination of rpS3 is required for resistance of glioblastoma cells to radiation-induced apoptosis.

An interaction between ribosomal protein S3 (rpS3) and nuclear factor kappa B or macrophage migration inhibitory factor in non-small-cell lung cancer is responsible for radioresistance. However, the role of rpS3 in glioblastoma (GBM) has not been investigated to date. Here we found that in irradiated GBM cells, rpS3 translocated into the nucleus and was subsequently ubiquitinated by ring finger protein 138 (RNF138). Ubiquitin-dependent degradation of rpS3 consequently led to radioresistance in GBM cells. To elucidate the apoptotic role of rpS3, we analyzed the interactome of rpS3 in ΔRNF138 GBM cells. Nuclear rpS3 interacted with DNA damage inducible transcript 3 (DDIT3), leading to DDIT3-induced apoptosis in irradiated ΔRNF138 GBM cells. These results were confirmed using in vivo orthotopic xenograft models and GBM patient tissues. This study aims to clarify the role of RNF138 in GBM cells and demonstrate that rpS3 may be a promising substrate of RNF138 for the induction of GBM radioresistance, indicating RNF138 as a potential target for GBM therapy.

The Reliabilities of Radiographic Measurements of Cervical Sagittal Alignment in Ankylosing Spondylitis.

STUDY DESIGN: This is a prospective study design. OBJECTIVE: To test the interobserver and intraobserver reliabilities of 5 specific measures of global cervical sagittal alignment in patients with ankylosing spondylitis (AS), and to suggest a better means of measuring cervical sagittal alignment. SUMMARY OF BACKGROUND DATA: The intraobserver and interobserver reliabilities of several different methods of measuring cervical lordosis have been reported. However, they have not been studied till yet in patients with AS. METHODS: Interobserver and intraobserver reliabilities of 5 specific measures of cervical lordosis were evaluated in patients with AS. Eighty patients with AS were allocated to a nonankylosis or an ankylosis group, and the reliabilities of the Cobb C1-C7, Cobb C2-C7, centroid, posterior tangent, and Ishihara index methods were evaluated. RESULTS: The intraclass and interclass correlation coefficients (ICCs) of all 5 methods were generally high. For the 80 study subjects, ICCs were ≥0.84 (excellent) for all 5 radiographic methods. However, comparison of the ICCs, 95% confidence intervals, and mean absolute differences (MAD) between groups with varying degrees of ankylosis showed that the reliability of lordosis measurements decreased as the severity of ankylosis increased. The 5 methods consistently demonstrated higher ICCs for both interobserver and intraobserver comparisons in the nonankylosis group. However, in the ankylosis group, the Cobb C1-C7 method demonstrated high ICCs for both interobserver and intraobserver comparisons, whereas the other 4 methods had high ICCs only for intraobserver comparisons. The intraobserver MADs were similar for the 5 methods (2.4-3.9), but the interobserver MADs of measurement methods in both groups showed low measurement reliability except for the Cobb C1-C7 methods. CONCLUSIONS: This study provides a reliability analysis of different cervical lordosis measurement methods in AS, and shows that the Cobb C1-C7 method provides a reliable means for measuring cervical lordosis in AS.

Use of (18)F-FDG PET to predict tumor progression and survival in patients with intermediate hepatocellular carcinoma treated by transarterial chemoembolization.

BACKGROUND/AIMS: (18)F-Fluorodeoxyglucose positron-emission tomography ((18)F-FDG PET) has been used to assess the biological behavior of hepatocellular carcinoma (HCC). In this study, we investigated the usefulness of (18)F-FDG PET for predicting tumor progression and survival in patients with intermediate Barcelona Clinic Liver Cancer (BCLC) intermediate-stage HCC treated by transarterial chemoembolization (TACE). METHODS: From February 2006 to March 2013, 210 patients treated with TACE, including 77 patients with BCLC intermediate-stage HCC, underwent examination by (18)F-FDG PET. (18)F-FDG uptake was calculated based on the tumor maximum (Tmax) standardized uptake value (SUV), the liver mean (Lmean) SUV, and the ratio of the Tmax SUV to the Lmean SUV (Tmax/Lmean). RESULTS: The mean follow-up period for the 77 patients (52 males, 25 females; average age, 63.3 years) was 22.2 months. The median time to progression of HCC in patients with a low Tmax/Lmean (< 1.83) and high Tmax/Lmean (≥ 1.83) was 17 and 6 months, respectively (p < 0.001). The median overall survival time of patients with a low and high Tmax/Lmean was 44 and 14 months, respectively (p = 0.003). Multivariate analysis revealed that the Tmax/Lmean was an independent predictor of overall survival (hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.210 to 3.156; p = 0.006) and tumor progression (HR, 2.05; 95% CI, 1.264 to 3.308; p = 0.004). CONCLUSIONS: (18)F-FDG uptake calculated by the Tmax/Lmean using PET predicted tumor progression and survival in patients with BCLC intermediate-stage HCC treated by TACE.

Dissociation of MIF-rpS3 complex and sequential NF-κB activation is involved in IR-induced metastatic conversion of NSCLC.

Frequent relapse and spreading of tumors during radiotherapy are principal obstacles to treatment of non-small cell lung cancer (NSCLC). In this study, we aimed to investigate how macrophage migration inhibitory factor (MIF) which is expressed at high levels in metastatic and primary lung cancer cells could regulate NSCLC metastasis in response to ionizing radiation (IR). The results indicated that MIF and ribosomal protein S3 (rpS3) were shown to be connected to inflammation, proliferation, and metastasis of NSCLC via IR-induced activation of the NF-κB pathway. Under unirradiated conditions, MIF physically established a complex with rpS3. MIF-rpS3 dissociation induced by IR activated NF-κB and made the expression of target genes of this factor transactivated in two NSCLC cell lines, A549, and NCI-H358. We also found that IR-induced dissociation of this complex led to increased secretion of pro-inflammatory cytokines and modulated the expression of epithelial-mesenchymal transition marker proteins. Finally, the effects of IR-induced dissociation of the MIF-rpS3 complex on tumor metastasis were confirmed by in vivo xenograft studies. Taken together, the present study revealed that dissociation of the MIF-rpS3 complex and subsequent activation of NF-κB is a critical post-IR exposure event that accounts for IR-induced metastatic conversion of NSCLC.

The association between psychiatric factors and the development of chronic dysphagia after anterior cervical spine surgery.

PURPOSE: Little data are available regarding the influence of psychiatric factors on chronic dysphagia after anterior cervical spine surgery. The purpose of this study was to identify associations between psychiatric factors and the development of chronic dysphagia in patients after anterior cervical spine surgery. METHODS: The authors prospectively examined 72 patients with degenerative disc disease of the cervical spine who were treated by single-level anterior cervical discectomy and fusion. Demographic data including age, gender, body mass index, and smoking status were collected. Short form-36, mental component scores (MCS), physical component scores (PCS), Neck Disability Indices (NDI), and the Neck Pain and Disability Scale (NPDS) were assessed before surgery and at final follow-up. Psychiatric conditions were evaluated using the Zung depression scale and the Zung anxiety scale. At 1 year postoperatively, patients were contacted by telephone to determine the presence and severity of dysphagia. For statistical analyses, patients were divided into two groups: group I, those with No or Mild dysphagia; and group II, those with Moderate or Severe dysphagia at 1 year after surgery. Potential risk factors of chronic dysphagia were evaluated by multivariate logistic regression analysis. RESULTS: The patients included 22 women and 50 men of overall average age 47.1 ± 7.8 years. The prevalences of No/Mild (group I) and Moderate/Severe (group II) dysphagia were 69.4% (50 patients) and 30.6% (22 patients), respectively. Mean preoperative NDI, NPDS, PCS, and MCS scores of 34.2, 44.8, 33.7, and 46.2 in the 72 study subject improved to 9.9, 16.1, 55.1, and 56.2, respectively, at 1 year after surgery. The mean preoperative ZDS and ZAS scores were 35.2 and 34.2, respectively. The two study groups were significantly different in terms of the presence of a psychiatric problem, preoperative NDIs, and MCS scores. However, multivariate logistic regression showed that the presence of a psychiatric problem prior to surgery (P = 0.005) was the only significant predictor of chronic dysphagia. CONCLUSIONS: The presence of a psychiatric problem seems to be an important risk factor of chronic dysphagia in patients with cervical disc herniation. The study shows that psychiatric factors should be evaluated prior to surgery to determine the risk of chronic dysphagia.

A case of mucolipidosis II presenting with prenatal skeletal dysplasia and severe secondary hyperparathyroidism at birth.

Mucolipidosis II (ML II) or inclusion cell disease (I-cell disease) is a rarely occurring autosomal recessive lysosomal enzyme-targeting disease. This disease is usually found to occur in individuals aged between 6 and 12 months, with a clinical phenotype resembling that of Hurler syndrome and radiological findings resembling those of dysostosis multiplex. However, we encountered a rare case of an infant with ML II who presented with prenatal skeletal dysplasia and typical clinical features of severe secondary hyperparathyroidism at birth. A female infant was born at 37(+1) weeks of gestation with a birth weight of 1,690 g (<3rd percentile). Prenatal ultrasonographic findings revealed intrauterine growth retardation and skeletal dysplasia. At birth, the patient had characteristic features of ML II, and skeletal radiographs revealed dysostosis multiplex, similar to rickets. In addition, the patient had high levels of alkaline phosphatase and parathyroid hormone, consistent with severe secondary neonatal hyperparathyroidism. The activities of ß-D-hexosaminidase and α-N-acetylglucosaminidase were moderately decreased in the leukocytes but were 5- to 10-fold higher in the plasma. Examination of a placental biopsy specimen showed foamy vacuolar changes in trophoblasts and syncytiotrophoblasts. The diagnosis of ML II was confirmed via GNPTAB genetic testing, which revealed compound heterozygosity of c.3091C>T (p.Arg1031X) and c.3456_3459dupCAAC (p.Ile1154GlnfsX3), the latter being a novel mutation. The infant was treated with vitamin D supplements but expired because of asphyxia at the age of 2 months.