Inhibition of protein arginine methyltransferase 6 activates interferon signaling and induces the apoptosis of endometrial cancer cells via histone modification.

Histone modification, a major epigenetic mechanism regulating gene expression through chromatin remodeling, introduces dynamic changes in chromatin architecture. Protein arginine methyltransferase 6 (PRMT6) is overexpressed in various types of cancer, including prostate, lung and endometrial cancer (EC). Epigenome regulates the expression of endogenous retrovirus (ERV), which activates interferon signaling related to cancer. The antitumor effects of PRMT6 inhibition and the role of PRMT6 in EC were investigated, using epigenome multi­omics analysis, including an assay for chromatin immunoprecipitation sequencing (ChIP­seq) and RNA sequencing (RNA­seq). The expression of PRMT6 in EC was analyzed using reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and immunohistochemistry (IHC). The prognostic impact of PRMT6 expression was evaluated using IHC. The effects of PRMT6­knockdown (KD) were investigated using cell viability and apoptosis assays, as well as its effects on the epigenome, using ChIP­seq of H3K27ac antibodies and RNA­seq. Finally, the downstream targets identified by multi­omics analysis were evaluated. PRMT6 was overexpressed in EC and associated with a poor prognosis. PRMT6­KD induced histone hypomethylation, while suppressing cell growth and apoptosis. ChIP­seq revealed that PRMT6 regulated genomic regions related to interferons and apoptosis through histone modifications. The RNA­seq data demonstrated altered interferon­related pathways and increased expression of tumor suppressor genes, including NK6 homeobox 1 and phosphoinositide­3­kinase regulatory subunit 1, following PRMT6­KD. RT­qPCR revealed that eight ERV genes which activated interferon signaling were upregulated by PRMT6­KD. The data of the present study suggested that PRMT6 inhibition induced apoptosis through interferon signaling activated by ERV. PRMT6 regulated tumor suppressor genes and may be a novel therapeutic target, to the best of our knowledge, in EC.

Bone morphogenetic protein signaling is a possible therapeutic target in gynecologic cancer.

Bone morphogenetic proteins (BMPs) belong to the transforming growth factor ß (TGFß) superfamily. BMPs play crucial roles in embryogenesis and bone remodeling. Recently, BMP signaling has been found to have diverse effects on different types of tumors. In this review, we summarized the effects of BMP signaling on gynecologic cancer. BMP signaling has tumor-promoting effects on ovarian cancer (OC) and endometrial cancer (EC), whereas it has tumor-suppressing effects on uterine cervical cancer (UCC). Interestingly, EC has frequent gain-of-function mutations in ACVR1, encoding one of the type I BMP receptors, which are also observed in fibrodysplasia ossificans progressiva and diffuse intrinsic pontine glioma. Little is known about the relationship between BMP signaling and other gynecologic cancers. Tumor-promoting effects of BMP signaling in OC and EC are dependent on the promotion of cancer stemness and epithelial-mesenchymal transition (EMT). In accordance, BMP receptor kinase inhibitors suppress the cell growth and migration of OC and EC. Since both cancer stemness and EMT are associated with chemoresistance, BMP signaling activation might also be an important mechanism by which OC and EC patients acquire chemoresistance. Therefore, BMP inhibitors are promising for OC and EC patients even if they become resistant to standard chemotherapy. In contrast, BMP signaling inhibits UCC growth in vitro. However, the in vivo effects of BMP signaling have not been elucidated in UCC. In conclusion, BMP signaling has a variety of functions, depending on the types of gynecologic cancer. Therefore, targeting BMP signaling should improve the treatment of patients with gynecologic cancer.

Multifaceted Functions of TWSG1: From Embryogenesis to Cancer Development.

Bone morphogenetic proteins (BMPs) play an important role in development. Twisted gastrulation BMP signaling modulator 1 (TWSG1) was initially identified as a regulator of the dorsoventral axis formation in Drosophila. The mechanism of BMP signaling modulation by TWSG1 is complex. TWSG1 inhibits BMP signaling by binding to BMP ligands including BMP4, whereas it enhances signaling by interacting with Chordin, a BMP antagonist. Therefore, TWSG1 can act as both a BMP agonist and antagonist. TWSG1 has various functions ranging from embryogenesis to cancer progression. TWSG1 knockout mice showed neural, craniofacial, and mammary defects. TWSG1 also regulated erythropoiesis and thymocyte development. Furthermore, the relationship between TWSG1 and cancer has been elucidated. Allelic loss of TWSG1 was detected in colorectal cancer. TWSG1 expression was upregulated in papillary thyroid carcinoma and glioblastoma but downregulated in gastric and endometrial cancers. TWSG1 suppressed BMP7-enhanced sphere formation and migration in endometrial cancer cells, indicating its tumor-suppressive role. Further studies are required to clarify the TWSG1 function and its association with BMP signaling in cancer development. Finally, TWSG1 is abundantly expressed in human and mouse ovaries and sustains follicular growth in rodent ovaries. Thus, TWSG1 has various functions ranging from fertility to cancer. Therefore, TWSG1 signaling modulation may be beneficial in treating specific diseases such as cancer.

Suspicious Positive Peritoneal Cytology (Class III) in Endometrial Cancer Does Not Affect Prognosis.

Positive peritoneal cytology is a poor prognostic factor in patients with advanced endometrial cancer. Suspicious positive peritoneal cytology (class III) is commonly encountered in clinical practice. However, no standard treatment protocol exists for its management. Here, we investigated a possible relationship between suspicious positive peritoneal cytology, disease stage, risk factors, and endometrial cancer prognosis. We included patients diagnosed with endometrial cancer who underwent total hysterectomy and peritoneal cytology at the University of Tokyo Hospital between 2008 and 2022. Overall, 670 patients were included in the analyses; both demographic and clinical data of the patients were collected. The proportion of patients with lymph node metastasis was significantly different between peritoneal cytology groups, showing lymph node metastasis to be more extensive in patients with positive or suspicious positive peritoneal cytology than in patients with negative peritoneal cytology (p < 0.05). Thirty-nine patients had suspicious positive peritoneal cytology. Omental resection and biopsy were performed in 16 cases. No case of omental metastasis was found. Among patients with suspected ascites cytology, no patient experienced symptom recurrence or death. Therefore, monitoring lymph node metastasis in suspicious positive cases is essential. Moreover, a change of treatment method based on the finding of suspected positive peritoneal cytology is not necessary.

A transcriptomic reevaluation of the accessory olfactory organ in Bichir (Polypterus senegalus).

Fish possess one olfactory organ called the olfactory epithelium (OE), by which various chemical substances are detected. On the other hand, tetrapods possess two independent olfactory organs called the main olfactory epithelium (MOE) and vomeronasal organ (VNO), each of which mainly detects general odorants and pheromones, respectively. Traditionally, the VNO, so-called concentrations of vomeronasal neurons, was believed to have originated in tetrapods. However, recent studies have identified a primordial VNO in lungfish, implying that the origin of the VNO was earlier than traditionally expected. In this study, we examined the presence/absence of the VNO in the olfactory organ of bichir (Polypterus senegalus), which is the most ancestral group of extant bony vertebrates. In particular, we conducted a transcriptomic evaluation of the accessory olfactory organ (AOO), which is anatomically separated from the main olfactory organ (MOO) in bichir. As a result, several landmark genes specific to the VNO and MOE in tetrapods were both expressed in the MOO and AOO, suggesting that these organs were not functionally distinct in terms of pheromone and odorant detection. Instead, differentially expressed gene (DEG) analysis showed that DEGs in AOO were enriched in genes for cilia movement, implying its additional and specific function in efficient water uptake into the nasal cavity other than chemosensing. This transcriptomic study provides novel insight into the long-standing question of AOO function in bichir and suggests that VNO originated in the lineage of lobe-finned fish during vertebrate evolution.

[A Case of Breast Metastasis from Renal Cell Carcinoma].

The patient was a woman in her 90s. Right radical nephrectomy for right renal cell carcinoma had been performed 2 years and 6 months ago. Since then, there had been no recurrence. However, computed tomography during postoperative follow- up period showed a 3 cm mass in the right breast, and the patient was referred to our department. Breast ultrasonography indicated a well-circumscribed, oval, and almost smooth-surfaced tumor, 27 mm in size, located in the D region of the right breast. Results of a core needle biopsy showed metastatic renal cell carcinoma and clear cell carcinoma. Preoperative examination confirmed intramammary metastases of renal cell carcinoma. Given that the patient did not experience systemic metastases, partial mastectomy of the right breast was performed. Metastatic renal cell carcinoma is associated with poor prognosis. Generally, standard treatment in this disease is chemotherapy. However, surgical resection is selected with the aim of improving the prognosis and achieving radical cure of patients with this complication if these patients are in an oligometastatic state and complete resection of metastatic lesions is feasible, as in the present case. To achieve radical cure, the patient underwent partial mastectomy under local anesthesia, which is a relatively minimally invasive surgery.

Compound heterozygous variants in the ABCG8 gene in a Japanese girl with sitosterolemia.

Sitosterolemia is an autosomal recessive disorder that affects lipid metabolism and is characterized by elevated serum plant sterol levels, xanthomas, and accelerated atherosclerosis. In this study, we report a novel nonsense single-nucleotide variant, c.225G > A (p.Trp75*), and an East Asian population-specific missense multiple-nucleotide variant, c.1256_1257delTCinsAA (p.Ile419Lys), in the ABCG8 gene in a compound heterozygous state observed in a Japanese girl with sitosterolemia.

The evolutionarily conserved deubiquitinase UBH1/UCH-L1 augments DAF7/TGF-ß signaling, inhibits dauer larva formation, and enhances lung tumorigenesis.

Modification of the transforming growth factor ß (TGF-ß) signaling components by (de)ubiquitination is emerging as a key regulatory mechanism that controls cell signaling responses in health and disease. Here, we show that the deubiquitinating enzyme UBH-1 in Caenorhabditis elegans and its human homolog, ubiquitin C-terminal hydrolase-L1 (UCH-L1), stimulate DAF-7/TGF-ß signaling, suggesting that this mode of regulation of TGF-ß signaling is conserved across animal species. The dauer larva-constitutive C. elegans phenotype caused by defective DAF-7/TGF-ß signaling was enhanced and suppressed, respectively, by ubh-1 deletion and overexpression in the loss-of-function genetic backgrounds of daf7, daf-1/TGF-ßRI, and daf4/R-SMAD, but not of daf-8/R-SMAD. This suggested that UBH-1 may stimulate DAF-7/TGF-ß signaling via DAF-8/R-SMAD. Therefore, we investigated the effect of UCH-L1 on TGF-ß signaling via its intracellular effectors, i.e. SMAD2 and SMAD3, in mammalian cells. Overexpression of UCH-L1, but not of UCH-L3 (the other human homolog of UBH1) or of the catalytic mutant UCH-L1C90A, enhanced TGF-ß/SMAD-induced transcriptional activity, indicating that the deubiquitination activity of UCH-L1 is indispensable for enhancing TGF-ß/SMAD signaling. We also found that UCH-L1 interacts, deubiquitinates, and stabilizes SMAD2 and SMAD3. Under hypoxia, UCH-L1 expression increased and TGF-ß/SMAD signaling was potentiated in the A549 human lung adenocarcinoma cell line. Notably, UCH-L1-deficient A549 cells were impaired in tumorigenesis, and, unlike WT UCH-L1, a UCH-L1 variant lacking deubiquitinating activity was unable to restore tumorigenesis in these cells. These results indicate that UCH-L1 activity supports DAF-7/TGF-ß signaling and suggest that UCH-L1's deubiquitination activity is a potential therapeutic target for managing lung cancer.

Simply Structured Conjugated Compounds with Cyanoacrylate or Acrylonitrile Groups for Sensing of p-Toluenethiol.

Simply structured conjugated compounds with cyanoacrylate (CA 1 - 4) and acrylonitrile (AN 1 - 4) terminal groups were synthesized by a Knoevenagel condensation reaction in one step and investigated for their recognition properties to p-toluenethiol by UV-vis, fluorescence spectra, and FT-IR measurements. When p-toluenethiol was added to CA 1, the FT-IR spectra revealed a cleavage of alkene caused by the addition reaction between p-toluenethiol and CA 1. An increase in p-toluenethiol concentration, a blue-shifted absorption band, and a decrease in the fluorescence intensity of CA 1 were observed because of the decrease in its effective conjugated length. Therefore, the most simply structured CA 1 was found to be the most effective and the most sensitive chemical sensor for p-toluenethiol.

A Familial Case of a Whole Germline CDC73 Deletion Discordant for Primary Hyperparathyroidism.

INTRODUCTION: Primary hyperparathyroidism (PHPT) occurs as part of familial syndromes, including CDC73-related disorders caused by germline pathogenic variants of the CDC73 gene, particularly in early adulthood. Herein, we report a familial case of a whole germline CDC73 deletion discordant for PHPT. CASE DESCRIPTION: A 15-year-old boy was admitted to our hospital because of persistent nausea and vomiting. Laboratory tests showed hypercalcemia (13.6 mg/dL), hypophosphatemia (2.4 mg/dL), and elevated intact PTH level (149 pg/mL). Imaging studies showed an enlarged single parathyroid gland. Thus, the diagnosis of PHPT was made. Microarray analysis of peripheral blood DNA showed a 3.4-Mb heterozygous deletion of 1q31 encompassing 11 genes, including CDC73. Total thyroidectomy/parathyroidectomy was performed; histology was compatible with parathyroid adenoma without any evidence of malignancy. DNA sequencing of the removed adenoma confirmed a hemizygous nonsense variant in the CDC73 gene in a mosaic manner, which was potentially involved in parathyroid tumorigenesis as the "second hit." Importantly, the same deletion was identified in his 52-year-old father who had an unremarkable medical history. CONCLUSIONS: These data clearly demonstrate the Knudson two-hit theory from a molecular viewpoint. Phenotypic variability and incomplete penetrance of CDC73-related disorders, even if caused by a gross deletion, should be noted in a clinical setting.

Prediction of biological characteristics of breast cancer using dual-phase FDG PET/CT.

PURPOSE: The aim of this study was to assess whether the retention index (RI) determined using dual-phase 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) reflects the malignant features of breast cancer. METHODS: A total of 1,523 patients with breast cancer were retrospectively evaluated. PET/CT scans were performed at 1 h and 2 h after FDG administration before treatment. The maximum standardized uptake value (SUVmax) at both time points (SUVmax1 and SUVmax2) in the primary tumour and RI were calculated. Primary tumour tissues were evaluated in terms of biological features, such as histology, nuclear grade, lymphovascular invasion and molecular subtype. RESULTS: Of the 1,523 patients, 463 (30.4%) had luminal A-like, 661 (43.4%) had luminal B-like, 229 (15.0%) had human epidermal growth factor receptor 2-positive (HER2-positive), and 157 (10.3%) triple-negative breast cancer. The median SUVmax1, SUVmax2 and RI values were 2.2, 2.3 and 2.6%, respectively. These metabolic parameters were correlated with tumour size, nodal metastasis, histology, nuclear grade, lymphovascular invasion, and molecular subtype (all P < 0.001). The median RI values were 0% in luminal A-like, 5.3% in luminal B-like, 6.9% in HER2-positive, and 11.4% in triple-negative breast cancer. RI was associated with malignant features when the tumour accumulated a significant amount of FDG. In a subanalysis of patients with tumours of stages T2 to T4, RI was correlated with nodal metastasis, histology, nuclear grade, and molecular subtype (luminal A-like 4.8%, luminal B-like 12.3%, HER2-positive 15.8%, and triple-negative 16.3%). CONCLUSION: RI determined using delayed-phase FDG PET/CT is associated with malignant features in breast cancers with significant FDG uptake. Dual-phase imaging was helpful in distinguishing luminal A-like breast cancer from luminal B-like, HER2-positive, and triple-negative breast cancers.

The Relationship between the Incidence of Summer-type Hypersensitivity Pneumonitis and Environmental Factors in Southern Tochigi Prefecture.

Objective Environmental and climatic changes have been occurring throughout the past 20 years in Japan. Correspondingly, the antigens that cause hypersensitivity pneumonitis might be changing. In an epidemiological survey of Japan in the 1980s, summer-type hypersensitivity pneumonitis (SHP) accounted for 74.4% of the cases of hypersensitivity pneumonitis. The epidemiological characteristics of this disease have not been reported since then. We investigated the annual changes in the number of cases of SHP and the factors affecting the results. Methods Cases that were diagnosed as SHP were retrieved from the medical records of our institute between 1990 and 2015. The diagnostic criteria proposed by the Japanese Ministry of Health, Labour and Welfare in 1990 were applied to obtain the definite diagnosis. Patients The study population included 25 diagnosed patients, including one intrafamilial case. The subjects were predominantly non-smoking women in their 50s and all lived in wooden houses that had been constructed more than 10 years previously. Results The number of cases that were diagnosed as SHP tended to decrease during the study period. However, temporal increases tended to occur in years with increased rainfall and decreased daylight hours. No relationship appeared to exist between the number of cases and high temperatures or humidity levels. Conclusion The incidence of SHP currently appears to be decreasing; however, the weather conditions in any given year might cause a temporal increase in the incidence rate.

Oligo(p-phenylene ethynylene) with Cyanoacrylate Terminal Groups and Graphene Composite as Fluorescent Chemical Sensor for Cysteine.

A chemical sensor for cysteine (Cys) was fabricated based on a fluorescent oligo(p-phenylene ethynylene)s (OPEs) and OPE-graphene oxide (GO) composite. OPE with cyanoacrylate terminal groups were synthesized by a Pd-catalyzed Sonogashira coupling reaction and Knoevenagel condensation for use as a chemical sensor for Cys. The optical properties and Cys sensing capability of the cyanoacrylate modified OPE and OPE-GO composite were investigated. In addition of Cys, the fluorescence of OPE was blue-shifted and decreased (fluorescence turn-off), while the fluorescence of the OPE-GO composite was enhanced (fluorescence turn-on). Thus, OPE with cyanoacrylate terminal groups and OPE-GO composite acts a highly sensitive fluorescent chemical sensor for Cys.

BipA Is Associated with Preventing Autoagglutination and Promoting Biofilm Formation in Bordetella holmesii.

Bordetella holmesii causes both invasive and respiratory diseases in humans. Although the number of cases of pertussis-like respiratory illnesses due to B. holmesii infection has increased in the last decade worldwide, little is known about the virulence factors of the organism. Here, we analyzed a B. holmesii isolate that forms large aggregates and precipitates in suspension, and subsequently demonstrated that the autoagglutinating isolate is deficient in Bordetella intermediate protein A (BipA) and that this deletion is caused by a frame-shift mutation in the bipA gene. A BipA-deficient mutant generated by homologous recombination also exhibited the autoagglutination phenotype. Moreover, the BipA mutant adhered poorly to an abiotic surface and failed to form biofilms, as did two other B. holmesii autoagglutinating strains, ATCC 51541 and ATCC 700053, which exhibit transcriptional down-regulation of bipA gene expression, indicating that autoagglutination indirectly inhibits biofilm formation. In a mouse intranasal infection model, the BipA mutant showed significantly lower levels of initial lung colonization than did the parental strain (P < 0.01), suggesting that BipA might be a critical virulence factor in B. holmesii respiratory infection. Together, our findings suggest that BipA production plays an essential role in preventing autoagglutination and indirectly promoting biofilm formation by B. holmesii.

Disinfectant-susceptibility of multi-drug-resistant Mycobacterium tuberculosis isolated in Japan.

BACKGROUND: Multi-drug-resistant Mycobacterium tuberculosis has been an important problem in public health around the world. However, limited information about disinfectant-susceptibility of multi-drug-resistant strain of M. tuberculosis was available. FINDINGS: We studied susceptibility of several Japanese isolates of multi-drug-resistant M. tuberculosis against disinfectants, which are commonly used in clinical and research laboratories. We selected a laboratory reference strain (H37Rv) and eight Japanese isolates, containing five drug-susceptible strains and three multi-drug-resistant strains, and determined profiles of susceptibility against eight disinfectants. The M. tuberculosis strains were distinguished into two groups by the susceptibility profile. There was no relationship between multi-drug-resistance and disinfectant-susceptibility in the M. tuberculosis strains. Cresol soap and oxydol were effective against all strains we tested, regardless of drug resistance. CONCLUSIONS: Disinfectant-resistance is independent from multi-drug-resistance in M. tuberculosis. Cresol soap and oxydol were effective against all strains we tested, regardless of drug resistance.

Factors that influence the pharmacokinetics of lamotrigine in Japanese patients with epilepsy.

PURPOSE: Lamotrigine (LTG) is used to treat epilepsy. The variability of LTG pharmacokinetics among individuals may be attributed to polymorphisms in the genes of uridine diphosphate glucuronosyltransferases (UGTs) 1A4 and UGT2B7 and/or combination with other drugs. In this study, we evaluated the association between LTG concentrations and patient characteristics such as genetic polymorphisms and the co-administration of antiepileptic drugs. METHODS: We recruited 122 patients with epilepsy. LTG concentrations were measured in blood samples from each patient under steady-state condition. We assessed the influence of multiple factors on LTG concentrations and derived a formula for predicting LTG concentrations using multiple linear regression analysis. RESULTS: We derived a formula to predict LTG concentrations that considers the daily dose of LTG, body weight, valproic acid concentration, phenytoin co-administration, and the co-administration of phenobarbital and/or carbamazepine as well as UGT1A4 142T>G and UGT2B7 -161C>T polymorphisms (adjusted coefficients of determination R (2) = 0.734). Furthermore, we used this formula to reveal a strong positive correlation between measured and predicted LTG concentrations (r (2) = 0.76, p < 0.001). CONCLUSION: We derived a formula that will be useful in clinical practice for predicting LTG concentrations in patients with epilepsy.

Comparison between 5-day aprepitant and single-dose fosaprepitant meglumine for preventing nausea and vomiting induced by cisplatin-based chemotherapy.

PURPOSE: We aimed to compare the preventive effect of 5-day administration of aprepitant with single administration of fosaprepitant meglumine against nausea and vomiting symptoms due to highly emetogenic chemotherapy regimens comprising cisplatin (CDDP). METHODS: Subjects were inpatients who underwent chemotherapy for gastric cancer, esophageal cancer, lung cancer, or head and neck cancer with a regimen comprising 60 mg/m(2) or higher dose of CDDP. In this randomised, open-label, controlled study, the subjects were assigned to a group given aprepitant for 5 days or a group given a single administration of fosaprepitant meglumine. The nausea and vomiting symptoms that emerged within 7 days after the first CDDP administration were investigated with a questionnaire form; the results were compared between the two groups. Risk factors affecting nausea and vomiting symptoms were also investigated. RESULTS: Of the 101 patients enrolled, 93 patients were included (48 in the 5-day aprepitant group and 45 in the single fosaprepitant meglumine group). No significant intergroup differences in the complete response rate or the complete control rate were found over the entire period. The nausea score tended to increase from day 3 in both groups, but no significant intergroup difference was observed. Furthermore, the investigation of risk factors affecting moderate or severe nausea symptoms indicated that the fosaprepitant meglumine administration was not a risk factor. CONCLUSIONS: Single administration of fosaprepitant meglumine was not inferior to 5-day administration of aprepitant for preventing acute and delayed nausea and vomiting symptoms occurring after administration of CDDP (60 mg/m(2) or higher).

Influence of glutamine synthetase gene polymorphisms on the development of hyperammonemia during valproic acid-based therapy.

PURPOSE: Valproic acid (VPA), which is widely used to treat epilepsy, migraine, and bipolar disorder, can causes severe hyperammonemia. However, the mechanism responsible for this adverse effect is not readily apparent. We previously reported that phenytoin coadministration is a strong risk factor for the development of hyperammonemia during VPA-based therapy. In this study, we focused on glutamine synthetase, which catalyzes the synthesis of glutamine from glutamate and ammonia and examined the association with the development of hyperammonemia during VPA-based therapy. METHODS: For this study, we recruited 202 Japanese pediatric patients having epilepsy. We selected three polymorphisms (rs10911070, rs10797771, and rs10911021) in the glutamine synthetase (GLUL) gene. Hyperammonemia was defined as a plasma ammonia level exceeding 200 or 170 µg/dL. We evaluated the association between the development of hyperammonemia during VPA-based therapy and the patient characteristics, including three GLUL polymorphisms. RESULTS: The number of patients who developed hyperammonemia during VPA-based therapy was 20 (9.9%) using the 200 µg/dL cutoff value and 30 (14.9%) using the 170 µg/dL cutoff value. Using a multivariate logistic regression analysis, the GLUL rs10797771 polymorphism and phenytoin coadministration in the 200 µg/dL cutoff value, and female in addition to two factors in the 170 µg/dL cutoff value, had significant associations with a plasma ammonia level elevation during VPA-based therapy. CONCLUSION: Phenytoin coadministration, GLUL rs10797771 polymorphism in the 200µg/dL cutoff value, and female in addition to two factors in the 170µg/dL cutoff value, are independent risk factors for elevated plasma ammonia levels during VPA-based therapy.