UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation

Background

Radioresistance is the major obstacle in radiation therapy (RT) for hepatocellular carcinoma (HCC). Dysregulation of DNA damage response (DDR), which includes DNA repair and cell cycle checkpoints activation, leads to radioresistance and limits radiotherapy efficacy in HCC patients. However, the underlying mechanism have not been clearly understood.

Methods

We obtained 7 pairs of HCC tissues and corresponding non-tumor tissues, and UBE2T was identified as one of the most upregulated genes. The radioresistant role of UBE2T was examined by colony formation assays in vitro and xenograft tumor models in vivo. Comet assay, cell cycle flow cytometry and γH2AX foci measurement were used to investigate the mechanism by which UBE2T mediating DDR. Chromatin fractionation and immunofluorescence staining were used to assess cell cycle checkpoint kinase 1(CHK1) activation. Finally, we analyzed clinical data from HCC patients to verify the function of UBE2T.

Results

Here, we found that ubiquitin-conjugating enzyme E2T (UBE2T) was upregulated in HCC tissues, and the HCC patients with higher UBE2T levels exhibited poorer outcomes. Functional studies indicated that UBE2T increased HCC radioresistance in vitro and in vivo. Mechanistically, UBE2T-RNF8, was identified as the E2-E3 pair, physically bonded with and monoubiquitinated histone variant H2AX/γH2AX upon radiation exposure. UBE2T-regulated H2AX/γH2AX monoubiquitination facilitated phosphorylation of CHK1 for activation and CHK1 release from the chromatin to cytosol for degradation. The interruption of UBE2T-mediated monoubiquitination on H2AX/γH2AX, including E2-enzyme-deficient mutation (C86A) of UBE2T and monoubiquitination-site-deficient mutation (K119/120R) of H2AX, cannot effectively activate CHK1. Moreover, genetical and pharmacological inhibition of CHK1 impaired the radioresistant role of UBE2T in HCC. Furthermore, clinical data suggested that the HCC patients with higher UBE2T levels exhibited worse response to radiotherapy.

Conclusion

Our results revealed a novel role of UBE2T-mediated H2AX/γH2AX monoubiquitination on facilitating cell cycle arrest activation to provide sufficient time for radiation-induced DNA repair, thus conferring HCC radioresistance. This study indicated that disrupting UBE2T-H2AX-CHK1 pathway maybe a promising potential strategy to overcome HCC radioresistance.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13046-020-01734-4.

Circular RNA hsa_circ_103809 suppresses hepatocellular carcinoma proliferation and invasion by sponging miR-620

OBJECTIVE

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, particularly in China. In recent years, numerous studies have investigated the roles of circular RNAs (circRNAs) in tumour development because circRNAs generally act as microRNA (miRNA) sponges to regulate gene expression. However, whether circRNAs are also involved in HCC progression remains largely unknown.

MATERIALS AND METHODS

In the present study, we identified a novel circRNA (hsa_circ_103809) and determined its expression in HCC tissues and cell lines by qRT-PCR assays. CCK8, colony formation, wound-healing and transwell assays were performed to assess the effects of hsa_circ_103809 and miR-620 on HCC cell proliferation, migration and invasion. Bioinformatics analysis and luciferase reporter assays were used to explore the correlation between hsa_circ_103809 and miR-620 in HCC cells.

RESULTS

The results showed that hsa_circ_103809 expression was significantly down- regulated in HCC tissues and cell lines. The ectopic expression of hsa_circ_103809 inhibited HCC cell proliferation, migration and invasion. In addition, we found that miR-620 expression was significantly up-regulated in HCC tissues and was negatively correlated with hsa_circ_103809 expression in HCC tissues. Furthermore, we found that hsa_circ_103809 could bind to miR-620 and that hsa_circ_103809 negatively regulates miR-620 expression. We also showed that hsa_circ_103809 inhibited the proliferation and invasion abilities of HCC cells by sponging miR-620.

CONCLUSIONS

Hsa_circ_103809 acts by binding to miR-620 and inhibiting the tumourigenicity of HCC. Thus, this circRNA may serve as a potential biomarker and novel therapeutic target of HCC.

[The phenotypes and genotypes in 314 patients with isolated methylmalonic acidemia]

Objectives: To summarize the clinical and genetic characteristics of the patients with isolated methylmalonic acidemia and investigate the strategies for the diagnosis, treatment and prevention. Methods: Three hundred and fourteen patients (180 males, 134 females) with isolated methylmalonic acidemia were ascertained from 26 provinces or cities across the mainland of China during January 1998 to March 2020. Genetic analysis was performed by Sanger sequencing, gene panel sequencing, whole exome sequencing, multiplex ligation-dependent probe amplification or quantitative PCR. According to the age of onset, the patients were divided to early-onset group (≤12 months of age) and the late-onset group (>12 months of age). They were treated by cobalamin, L-carnitine and (or) special diet and symptomatic treatment. Statistical analysis was done using Chi-square test. Results: Fifty-eight of 314 (18.5%) patients were detected by Newborn screening using liquid chromatography tandem mass spectrometry. Five cases (1.6%) had a postmortem diagnosis. Two hundred and fifty-one patients (79.9%) were clinically diagnosed with an age of onset ranged from 3 hours after birth to 18 years. One hundred and fifty-nine patients (71.0%) belonged to early-onset groups, 65 patients (29.0%) belonged to the late-onset group. The most common symptoms were metabolic crises, psychomotor retardation, epilepsy, anemia and multiple organ damage. Metabolic acidosis and anemia were more common in early-onset patients than that in late-onset patients (20.8%(33/159) vs. 9.2% (6/65), 34.6% (55/159) vs. 16.9% (11/165), χ(2)=4.261, 6.930, P=0.039, 0.008). Genetic tests were performed for 236 patients (75.2%), 96.2%(227/236) had molecular confirmation. One hundred and twenty-seven variants were identified in seven genes (MMUT, MMAA, MMAB, MMADHC, SUCLG1, SUCLA2, and MCEE), of which 49 were novel. The mut type, caused by the deficiency of methylmalonyl-CoA mutase, was the most common (n=211, 93%) cause of this condition. c.729_730insTT, c.1106G>A and c.914T>C were the three most frequent mutations in MMUT gene. The frequency of c.914T>C in early-onset patients was significantly higher than that in late-onset patients (8.3% (18/216) vs. 1.6% (1/64), χ(2)=3.859, P=0.037). Metabolic crisis was more frequent in mut type than the other types (72.6% (114/157) vs. 3/13, χ(2)=13.729, P=0.001),developmental delay and hypotonia were less frequent in mut type (38.2% (60/157) vs. 9/13, 25.5% (40/157) vs. 8/13, χ(2)=4.789, 7.705, P=0.030, 0.006). Of the 58 patients identified by newborn screening, 44 patients (75.9%) who were treated from asymptomatic phase developed normally whereas 14 patients (24.1%) who received treatment after developing symptoms exhibited varying degrees of psychomotor retardation. Conclusions: The characteristics of phenotypes and genotypes among Chinese patients with isolated methylmalonic acidemia were analyzed. Expanded the mutation spectrum of the associated genes. Because of the complex clinical manifestations and severe early onset of isolated methylmalonic acidemia, Newborn screening is crucial for early diagnosis and improvement of prognosis. MMUT gene is recommended for carrier screening as an effort to move the test earlier as a part of the primary prevention of birth defects.

AB1277 AUTOANTIBODIES IN NLRP3-ASSOCIATED AUTOINFLAMMATORY DISEASE: A CASE REPORT AND LITERATURE REVIEW

Background:

We present the first report of high-titer autoantibodies inNLRP3-associated autoinflammatory disease(NLRP3-AID).Because systemic autoinflammatory disease(SAID) is characterised by the lack of autoreactive T-cells or autoantibodies,we made a systemic review on the theme of autoantibody in SAID to clarify this phenomenon.

Objectives:

We present the first report of high-titer autoantibodiesNLRP3-AID, and discuss autoantibody in classical SAID.

Methods:

We collected the clinical data of the patient withNLRP3-AID who had high-titer autoantibodies,and made a systemic review about autoantibody in SAID.

Results:

A 38-year-old Chinese Han patient was definitely diagnosed asNLRP3-AID because of cold-triggered urticaria-like rash and fever,arthralgia,binaural sensorineural deafness,chronic meningitis,high inflammatory marker and de novoNLRP3T348M variant. Figure 1 shows pedigree of the patient.Meanwhile,she had positive antinuclear antibody(ANA) with a nucleolar pattern of 1:160, positive anti-β2GPI antibody 54-68 AU/ml (normal range < 20 AU/ml) and positive lupus anticoagulant 1.24-1.29 (normal range ≤ 1.2). Literature review found that 13 articles reported autoantibodies in Familial Mediterranean fever (FMF), and there was no autoantibody reported in hyperimmunoglobulinemia D syndrome (HIDS),TNF receptor–associated periodic syndrome(TRAPS) andNLRP3-AID. The prevalence of ANA,anti-dsDNA,RF and anti-CCP in patients with FMF was similar to healthy controls.

Fig. 1.

Pedigree of the patient. The black arrow indicates the proband. The asterisks indicate the individuals who had clinical manifestations and carry the NLRP3 T348M variant.

Conclusion:

Patients withNLRP3-AID can have high-titer ANA and APLs by accident. If patients with high-titer autoantibodies have characteristic manifestations of SAIDs instead of typical features of autoimmune diseases, we should make the final diagnosis through detailed investigation and genetic testing.

References:

[1]Ben-Chetrit E, Gattorno M, Gul A, et al. Consensus proposal for taxonomy and definition of the autoinflammatory diseases (AIDs): a Delphi study. Annals of the rheumatic diseases 2018; 77(11): 1558-65.

[2]Kuemmerle-Deschner JB, Ozen S, Tyrrell PN, et al. Diagnostic criteria for cryopyrin-associated periodic syndrome (CAPS). Annals of the rheumatic diseases 2017; 76(6): 942-7.

Disclosure of Interests:

None declared

Venturiales

Members of Venturiales (Dothideomycetes) are widely distributed, and comprise saprobes, as well as plant, human and animal pathogens. In spite of their economic importance, the general lack of cultures and DNA data has resulted in taxa being poorly resolved. In the present study five loci, ITS, LSU rDNA, tef1, tub2 and rpb2 are used for analysing 115 venturialean taxa representing 30 genera in three families in the current classification of Venturiales. Based on the multigene phylogenetic analysis, morphological and ecological characteristics, one new family, Cylindrosympodiaceae, and eight new genera are described, namely Bellamyces, Fagicola, Fraxinicola, Fuscohilum,Neofusicladium, Parafusicladium, Pinaceicola and Sterila. In addition, 12 species are described as new to science, and 41 new combinations are proposed. The taxonomic status of 153 species have been re-evaluated with 20 species excluded from Venturiales. Based on this revision of Venturiales, morphological characteristics such as conidial arrangement (solitary or in chains) or conidiogenesis (blastic-solitary, sympodial or annellidic), proved to be significant at generic level. Venturia as currently defined represents a generic complex. Furthermore, plant pathogens appear more terminal in phylogenetic analyses within Venturiaceae and Sympoventuriaceae, suggesting that the ancestral state of Venturiales is most likely saprobic.

Bibliometrics Analysis of Forensic Toxicology Literature of Mainland Chinese Scholars in SCIE Journals

Abstract

Objective To conduct bibliometrics analysis of forensic toxicology literature of mainland Chinese scholars published in SCIE journals between 1998 and 2018. Methods Gephi 0.9.2 software was used for bibliometrics analysis. The status of forensic toxicology research in mainland China was network visualized through data analysis of institutional cooperation, author collaboration, fund support, keywords co-occurrence as well as literature interpretation. Results The total number of papers published in SCIE journals in the past twenty years by mainland Chinese scholars was 242, and increased year by year. Thematic studies, such as analysis and evaluation of toxins in hair, identification of new psychoactive substances, optical enantiomer analysis of amphetamines, analysis of toxic animal and plant components, etc, reached the international advanced level. Conclusion The forensic toxicology discipline in our country has developed rapidly in recent years. The opening and development of forensic science in colleges and universities, the constant emerging of new research teams, especially the funding of major special projects of National Natural Science Foundation of China and the Ministry of Science and Technology, have promoted high level research output and academic status of Chinese forensic toxicology on the international stage.

[A report of clinical characteristics of 2 Chinese pedigrees with haploinsufficiency of A20 and literature review]

Objective: To summarize the clinical characteristics of patients with haploinsufficiency of A20 (HA20). Methods: The clinical manifestations, laboratory examinations, treatment, outcome and genetic analysis of 4 cases with HA20 hospitalized in Peking Union Medical College Hospital were analysed.Further literature review was done after searching articles in PubMed and Wangfang databases with the key words "HA20" "A20 haploinsufficiency" "TNFAIP3" up to the date of September 2019. Results: The 4 patients were a father and a daughter, as well as a mother and a daughter. Their phenotypes were quite variable, but all of them have been suffering from recurrent oral ulcer since childhood. Elevation of C-reactive protein (13-33 mg/L) and erythrocyte sedimentation rate (21-60 mm/1h) were found in these 4 patients, and there was positive antinuclear antibody in proband 1.The father in pedigree 1 and the 2 patients in pedigrees 2 have been diagnosed with Behçet disease and the proband 1 with undifferentiated connective tissue disease. The 2 patients in pedigree 1 have developed Hashimoto's thyroiditis. After gene sequencing analysis, it was found that all the 4 patients have heterozygous nonsense mutations in TNFAIP3 gene, that is, c.811C>T, p.R271X in pedigree 1 and c.133C>T, p.R45X in pedigree 2.The diagnosis of HA20 was eventually established when sequencing results and their clinical manifestations were both compatible with this disease.A total of 21 articles were retrieved, all in English, with a total of 91 cases from 39 families (including the 4 cases reported in this paper). HA20 was reported more often in female (57, 64.8%). Most patients develop symptoms from childhood, but as many as 53.4% (47 cases) are not correctly diagnosed until adulthood. Oral ulcers, genital ulcers, periodic fever, gastrointestinal symptoms, rashes, and arthritis are the primary manifestations.Hashimoto's thyroiditis is the most common autoimmune diseases that HA20 patients coexist with. Laboratory tests were characterized by significantly elevated inflammatory markers and low to moderate titers of autoantibodies in some patients.Most HA20 patients were reported to have nonsense mutations or shift mutations of TNFAIP3 gene, which leads to truncation of A20 protein, and only a small number of patients have missense mutation. In terms of treatment, anti-TNF treatment and anti-interleukin 1 is believed to be an effective and the most optimal therapy. The treatment effect is variable and requires long term observations. Conclusions: The clinical phenotypes of HA20 are complex. For patients with both autoinflammatory and autoimmune characteristics, family history should be inquired in detail and gene sequencing should be performed if necessary.

[Preoperative imaging and electrophysiological evaluation of cochlear implantation in children with cochlear nerve dysplasia]

Objective:The aim of this study is to investigate the use of CT, magnetic resonance imaging （MRI）, functional magnetic resonance （fMRI） and electrical evoked auditory brainstem response in children with cochlear nerve deficiency （CND） before cochlear implantation （CI） （electrically evoked auditory brain stem response, EABR） evaluated auditory pathway, auditory cortex function, and cochlear nerve function. Method:Of 6 children with bilateral profound sensorineural hearing loss, bilateral internal auditory meatus stenosis was diagnosed by CT as in 4 cases and unilateral internal auditory meatus stenosis in 1 case. In 3 cases, oblique sagittal MRI reconstruction of the internal auditory meatus showed only facial nerve and vestibular nerve existence. 6 cases were diagnosed as CND by imaging, among which underwent fMRI and EABR in 3 cases, respectively. All the children received unilateral CI and were followed up for at least 1 year after hearing and speech rehabilitation. Result:fMRI was examed in 3 cases with CND. It showed that the right auditory cortex was activated in 1 case after sound given to the left ear but no activation was found in the left cortex when sound given to the right ear. 1 case showed activation in bilateral transverse temporal gyrus while sound was given to the left, right and both ears at 2000Hz. Another case had no activation in both auditory cortex. EABR detection elicited V wave in 2 of 3 cases. 6 children received audiological and speech evaluation 1 month, 6 and 12 months after CI. Among them, the hearing level was improved within 6 months after surgery in 4 cases, and the threshold of sound field was （48.15±6.60） dB HL, MAIS and CAP scores were improved. However, SIR score improvement is limited in 3 cases. The hearing level was improved in 1 case, but speech rehabilitation was poor mainly due to the older age. Conclusion:Preoperative comprehensive application of imaging and electrophysiological evaluation of children with CND can more accurately assess the integrity of the auditory pathway and understand the function of the cochlear nerve. It has important reference significance for whether or not to perform surgery. There was a significant difference in auditory speech rehabilitation after CND in children with CND.

[Tuberculous otomastoiditis presenting as hydrotympanum: one case report]

Summary To study the clinical features, diagnosis and treatments of tuberculous otomastoiditis. One case is reported and literatures are reviewed. In this report, the specimen of the middle ear revealed the presence of acid fast bacilli（AFB）, grew mycobacterium tuberculosis on a culture. Lung CT scans demonstrated tuberculosis. After anti-tuberculosis therapy, the symptoms disappeared and did not recur in 3 years. Hydrotympanum can be the early symptom of tuberculous otomastoiditis. When persistent otorrhea can not be improved by conventional therapy, tuberculous otomastoiditis should be considered as one of the differential diagnosis.

Establishment and Its Application of UPLC-MS/MS Method for 20 Fentanyl-related Substances in Blood

Objective To establish an ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） rapid determination method for simultaneous analysis of 20 fentanyl-related substances in blood. Methods With fentanyl-D₅ as an internal standard, the blood was extracted by liquid-liquid extraction （LLE）, then separated with an ACQUITY UPLC HSS T₃ chromatographic column, and finally 20 fentanyl-related substances were simultaneously analyzed with multiple reaction monitoring （MRM） mode. Results The limits of detection （LOD） of all compounds were 0.02-0.03 ng/mL, and the limits of quantitation （LOQ） were 0.05-0.2 ng/mL. Within the mass concentration range of 0.05-40 ng/mL, 20 fentanyl-related substances had a good linear relationship, and correlation coefficients were larger than 0.99. The accuracy of the method was 87.69%-114.68% and the extraction recovery rate was 85.35%-101.80%, and no significant matrix effect was observed. The established method was successfully applied to the detection of sufentanil in rat blood after sufentanil was injected. Sufentanil could still be detected in blood of rats 10 h after sufentanil injection. Conclusion The established method has the advantages of simple pretreatment, high sensitivity and good selectivity, and can be used for the determination of fentanyl-related substances in forensic toxicology analysis.

[An analysis of the results of video head impulse test in benign paroxysmal vertigo of childhood]

Objective:This study was to analyze the results of video head impulse test (vHIT) of benign paroxysmal vertigo of childhood (BPVC) in order to determine the potential value of vHIT in the diagnosis and treatment for BPVC and to discuss its possible pathogenesis of BPVC. Method:Thirty-six children with BPVC were enrolled. No hearing loss and skull abnormality were found in these children as assessed by pure tone audiometry, acoustic impedance, CT or MRI scan. The vHIT was carried out, and main outcome measures were the gain of vestibulo-ocular reflex, gain asymmetry, and refixation saccades. Eleven healthy children were selected as normal control who came to our hospital for doing a routine checkup and have no history of dizziness. The differences of vHIT results between these two groups were analyzed. Result:①The vHIT results in control group were normal. In all BPVC subjects, abnormalities were detected in 9 patients (25.0%),including vHIT gains decline in 3 patients, abnormal symmetry in 4 patients, and abnormal isolated overt saccades in 2 patients.②The average saccadic gain in different canals of BPVC group was 1.03±0.14, 1.01±0.15, 1.13±0.31, 1.18±0.36, 1.21±0.33, 1.14±0.30 in left horizontal, right horizontal, left anterior, right posterior, right anterior, left posterior canal, respectively; while in normal group, it was 1.14±0.15, 1.18±0.09, 1.16±0.30, 1.18±0.40, 1.34±0.26, 1.30±0.20, respectively. Significant statistical difference was found only in horizontal canals between these two groups (P<0.05). ③Asymmetry of the three pairs of conjugated semicircular canals was 0.04±0.07 (horizontal canal), 0.06±0.04 (left anterior and right posterior canal), 0.06±0.04 (right anterior and left posterior canal) in BPVC group, respectively; while in control group, it was 0.02±0.02, 0.04±0.03, 0.04±0.04,respectively. There was no statistical difference between the two groups (P>0.05). Conclusion:A certain proportion of abnormal peripheral vestibule function in children with BPVC was found. vHIT is a "child friendly," relatively easytouse, and simple tool to evaluate each of the 6 semicircular canals, which may offer some potential clinical information for assessing the vestibule dysfunction for BPVC.

[Acoustic absorbance characteristics of wideband tympanometry in patients with Meniere's disease]

Objective:To study acoustic absorbance characteristics of wideband tympanometry in patients with unilateral Meniere's disease. Method:Acoustic absorbance were detected using wideband tympanometry in 36 patients with unilateral Meniere's disease and 39 control subjects excluding inner ear and middle ear disease. All patients with Meniere's disease underwent electrocochleography, gadolinium contrast internal auditory canal MRI, pure tone test. The integral area formed by the absorbance curve on peak pressure and x-axis(frequency) was calculated. Student's t-test was used to compare integral areas difference of 2 ears in Meniere's disease patients and control group. Result:The integral area of absorbance was greater in affected side than unaffected side and there was no difference in peak values of absorbance between 2 ears in Meniere's disease patients. There was no significant difference in areas between Meniere's disease in different grade(P>0.05). Peak value of absorbance and difference value of absorbance were not significant between Meniere's disease patients and normal control. Only 61.11% Meniere's disease patients showed -SP/AP＞0.4 and 95.24% showed endolymphatic hydrops in affected side. Conclusion:Affected side in patients with Meniere's disease showed higher integral area of absorbance than other side,which is high sensitive but not specific.