USP4 regulates ribosome biogenesis and protein synthesis for hematopoietic stem cell regeneration and leukemia progression.

Enhanced ribosome biogenesis and protein synthesis are required for cell proliferation. During hematopoietic regeneration, hematopoietic stem cells (HSCs) proliferate rapidly to replenish the hematopoietic system. How HSCs respond and regulate ribosome biogenesis and protein synthesis during regeneration remains unclear. Here, we analyzed the expression of a series of ubiquitin-specific-proteases (USPs) during HSC regeneration. We found USP4 expression is significantly increased in proliferating HSCs. Further functional and mechanistic investigations revealed a crucial regulatory function of USP4 in HSC regeneration and leukemia progression by modulating ribosome biogenesis and protein synthesis. USP4 deubiquitinates and stabilizes PES1 to facilitate ribosome biogenesis and protein synthesis in proliferative HSCs and leukemic cells. Usp4 deletion significantly decreases protein synthesis, proliferation and reconstitution capacity of HSCs. Usp4 inhibition suppresses ribosome biogenesis and proliferation of leukemic cells, and prolongs the survival of AML (Acute myeloid leukemia) mice. These findings provide a new insight into the response mechanism of ribosome biogenesis and protein synthesis in HSCs, and their contribution to leukemia progression.

The association between polychlorinated dibenzo-p-dioxin exposure and cancer mortality in the general population: a cohort study.

Introduction: Earlier research has indicated that being exposed to polychlorinated dibenzo-p-dioxins (PCDDs) in the workplace can heighten the likelihood of cancer-related deaths. Nevertheless, there is limited information available regarding the connection between PCDD exposure and the risk of cancer mortality in the general population (i.e., individuals not exposed to these substances through their occupation). Methods: The National Health and Nutrition Examination Survey (NHANES) detected PCDDs in the general population, and the death data were recently updated as of December 31, 2019. We conducted Cox regression analysis and controlled for covariates including age, gender, ethnicity, educational attainment, physical activity, alcohol intake, NHANES survey period, BMI category, cotinine concentration, and household earnings. Results: After accounting for confounding factors, the findings indicated that for each incremental rise of 1 log unit in 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin, there was a 76% rise in the likelihood of death from any cause, with a p value of 0.003. An increase of 1 log unit in the concentration of 1,2,3,4,6,7,8-heptachlorodibenzofuran could potentially lead to a 90% higher risk of cancer mortality, as indicated by a p value of 0.034 and a 95% confidence interval of 0.05-2.43. As the concentrations of 1,2,3,4,6,7,8-heptachlorodibenzofuran increased, the dose-response curve indicated a proportional rise in the risk of cancer mortality, accompanied by a linear p value of 0.044. The sensitivity analysis demonstrated that our findings were resilient. Discussion: In the general population, an elevated risk of cancer mortality was observed in PCDDs due to the presence of 1,2,3,4,6,7,8-heptachlorodibenzofuran. Mechanistic research is required to further confirm it.

Association of organophosphate flame retardants with all-cause and cause-specific mortality among adults aged 40 years and older.

The longitudinal associations of urinary concentrations of diphenyl phosphate (DPHP), bis(2-chloroethyl) phosphate (BCEP), and bis(1,3-dichloro-2-propyl) phosphate (BDCPP) with all-cause, cardiovascular, and cancer mortality in a population of adults aged 40 years and older are still unclear. A total of 3238 participants were included in this cohort study. Urinary BCEP levels were positively associated with all-cause mortality and cardiovascular mortality. Specifically, a logarithmic increase in BCEP concentration was related to a 26 % higher risk of all-cause mortality and a 32 % higher risk of cardiovascular mortality. No significant associations were observed for DPHP and BDCPP in relation to mortality. Doseresponse analysis confirmed the linear associations of BCEP with all-cause and cardiovascular mortality and the nonlinear inverted U-shaped association between DPHP exposure and all-cause mortality. Notably, the economic burden associated with BCEP exposure was estimated, and it was shown that concentrations in the third tertile of BCEP exposure incurred approximately 507 billion dollars of financial burden for all-cause mortality and approximately 717 billion dollars for cardiovascular mortality. These results highlight the importance of addressing exposure to BCEP and its potential health impacts on the population. More research is warranted to explore the underlying mechanisms and develop strategies for reducing exposure to this harmful chemical.

A Structure-Aware Hierarchical Graph-Based Multiple Instance Learning Framework for pT Staging in Histopathological Image.

Pathological primary tumor (pT) stage focuses on the infiltration degree of the primary tumor to surrounding tissues, which relates to the prognosis and treatment choices. The pT staging relies on the field-of-views from multiple magnifications in the gigapixel images, which makes pixel-level annotation difficult. Therefore, this task is usually formulated as a weakly supervised whole slide image (WSI) classification task with the slide-level label. Existing weakly-supervised classification methods mainly follow the multiple instance learning paradigm, which takes the patches from single magnification as the instances and extracts their morphological features independently. However, they cannot progressively represent the contextual information from multiple magnifications, which is critical for pT staging. Therefore, we propose a structure-aware hierarchical graph-based multi-instance learning framework (SGMF) inspired by the diagnostic process of pathologists. Specifically, a novel graph-based instance organization method is proposed, namely structure-aware hierarchical graph (SAHG), to represent the WSI. Based on that, we design a novel hierarchical attention-based graph representation (HAGR) network to capture the critical patterns for pT staging by learning cross-scale spatial features. Finally, the top nodes of SAHG are aggregated by a global attention layer for bag-level representation. Extensive studies on three large-scale multi-center pT staging datasets with two different cancer types demonstrate the effectiveness of SGMF, which outperforms state-of-the-art up to 5.6% in the F1 score.

Childhood Leukemia Classification via Information Bottleneck Enhanced Hierarchical Multi-Instance Learning.

Leukemia classification relies on a detailed cytomorphological examination of Bone Marrow (BM) smear. However, applying existing deep-learning methods to it is facing two significant limitations. Firstly, these methods require large-scale datasets with expert annotations at the cell level for good results and typically suffer from poor generalization. Secondly, they simply treat the BM cytomorphological examination as a multi-class cell classification task, thus failing to exploit the correlation among leukemia subtypes over different hierarchies. Therefore, BM cytomorphological estimation as a time-consuming and repetitive process still needs to be done manually by experienced cytologists. Recently, Multi-Instance Learning (MIL) has achieved much progress in data-efficient medical image processing, which only requires patient-level labels (which can be extracted from the clinical reports). In this paper, we propose a hierarchical MIL framework and equip it with Information Bottleneck (IB) to tackle the above limitations. First, to handle the patient-level label, our hierarchical MIL framework uses attention-based learning to identify cells with high diagnostic values for leukemia classification in different hierarchies. Then, following the information bottleneck principle, we propose a hierarchical IB to constrain and refine the representations of different hierarchies for better accuracy and generalization. By applying our framework to a large-scale childhood acute leukemia dataset with corresponding BM smear images and clinical reports, we show that it can identify diagnostic-related cells without the need for cell-level annotations and outperforms other comparison methods. Furthermore, the evaluation conducted on an independent test cohort demonstrates the high generalizability of our framework.

EVA1A regulates hematopoietic stem cell regeneration via ER-mitochondria mediated apoptosis.

Excessive protein synthesis upon enhanced cell proliferation frequently results in an increase of unfolded or misfolded proteins. During hematopoietic regeneration, to replenish the hematopoietic system, hematopoietic stem cells (HSCs) are activated and undergo a rapid proliferation. But how the activated HSCs respond to the proliferation pressure is still ambiguous; The proper control of the functional reservoir in the activated HSCs remains poorly understood. Here, we show a significant upregulation of EVA1A protein associated with the increase of ER stress during hematopoietic regeneration. Deletion of Eva1a significantly enhances the regeneration capacity of HSCs by inhibiting the ER stress-induced apoptosis. Mechanistically, the expression of EVA1A protein was upregulated by CHOP, and thereby promoted the ER-mitochondria interlinking via MCL1, which resulted in mitochondria-mediated apoptosis. These findings reveal a pathway for ER stress responses of HSCs by the EVA1A mediated apoptosis, which play an important role in HSCs regeneration.

A semi-supervised multi-task learning framework for cancer classification with weak annotation in whole-slide images.

Cancer region detection (CRD) and subtyping are two fundamental tasks in digital pathology image analysis. The development of data-driven models for CRD and subtyping on whole-slide images (WSIs) would mitigate the burden of pathologists and improve their accuracy in diagnosis. However, the existing models are facing two major limitations. Firstly, they typically require large-scale datasets with precise annotations, which contradicts with the original intention of reducing labor effort. Secondly, for the subtyping task, the non-cancerous regions are treated as the same as cancerous regions within a WSI, which confuses a subtyping model in its training process. To tackle the latter limitation, the previous research proposed to perform CRD first for ruling out the non-cancerous region, then train a subtyping model based on the remaining cancerous patches. However, separately training ignores the interaction of these two tasks, also leads to propagating the error of the CRD task to the subtyping task. To address these issues and concurrently improve the performance on both CRD and subtyping tasks, we propose a semi-supervised multi-task learning (MTL) framework for cancer classification. Our framework consists of a backbone feature extractor, two task-specific classifiers, and a weight control mechanism. The backbone feature extractor is shared by two task-specific classifiers, such that the interaction of CRD and subtyping tasks can be captured. The weight control mechanism preserves the sequential relationship of these two tasks and guarantees the error back-propagation from the subtyping task to the CRD task under the MTL framework. We train the overall framework in a semi-supervised setting, where datasets only involve small quantities of annotations produced by our minimal point-based (min-point) annotation strategy. Extensive experiments on four large datasets with different cancer types demonstrate the effectiveness of the proposed framework in both accuracy and generalization.

Membrane dynamics of ATG4B and LC3 in autophagosome formation.

The biogenesis of autophagosomes provides the basis for macroautophagy to capture and degrade intracellular cargoes. Binding of the autophagy-related protein ATG8/LC3 to autophagic membranes is essential to autophagosome formation, which involves the specific and dynamic processing of ATG8/LC3 by cysteine protease ATG4. However, to date, the mechanism whereby ATG4 is recruited to the membranes, the interaction of ATG4 and ATG8/LC3 on the membranes, and its role in the growth of phagophore are not completely understood. Here, we used fluorescence recovery after photobleaching to monitor the turnover of GFP-tagged ATG4B and LC3B in living animal cells. The data show that ATG4B localizes to early autophagic membranes in an LC3B-dependent manner. During autophagy, ATG4B and LC3B undergo rapid cytosol/isolation membrane exchange but not at the cytosol/completed autophagosome. In addition, ATG4B activity controls the efficiency of autophagosome formation by impacting the membrane binding/dissociation of LC3B. These data suggest that ATG4 and LC3 play interdependent roles in the formation of autophagosomes.

An Exploration of Mutagenesis in a Family with Cleidocranial Dysplasia without RUNX2 Mutation.

Cleidocranial dysplasia (CCD) is an autosomal dominant inheritable skeletal disorder characterized by cranial dysplasia, clavicle hypoplasia, and dental abnormalities. Mutations involving Runt-related transcription factor 2 (RUNX2) are currently the only known molecular etiology for CCD but are not identified in all CCD patients. No RUNX2 abnormality can be detected in about 20-30% of patients, and the molecular cause remains unknown. The present study includes a family case with typical features of CCD. RUNX2 mutation was first screened by sequencing analysis, and no mutation was detected. Copy number alterations of the RUNX2 gene were then measured by quantitative PCR and multiplex ligation-dependent probe amplification (MLPA). No copy number variation in RUNX2 could be detected. We performed whole-exome sequencing (WES) to identify the underlying genetic mutations. Unexpectedly, no abnormalities could be detected in genes related to the RUNX2 signaling pathway. Therefore, it was supposed that other new unknown gene variations might contribute to the CCD phenotype. We focused on Immunoglobulin superfamily member 10 (IGSF10), a gene related to bone development. An IGSF10 frameshift mutation (c.6001_6002delCT, p.Leu2001Valfs*24) was detected by WES. Sanger sequencing verified that this mutation was only detected in the patient and her affected mother but not in her unaffected father. Bioinformatics studies demonstrated that this mutation could change the 3D structure of the IGSF10 protein and severely damage its function. In addition, alkaline phosphatase (ALP) activity and the ability to form mineralized nodules were inhibited by IGSF10 knockdown compared with normal controls. The expression of bone sialoprotein (BSP) was significantly reduced by IGSF10 knockdown, but not that of other osteogenic markers. Our results provide new genetic evidence that IGSF10 mutation might contribute to CCD.

[Effect of Laptm4b Deletion on Hematopoietic Stem and Progenitor Cells Homeostasis in Mice].

OBJECTIVE: To investigate the effect of lysosomal-associated protein transmembrane-4 Beta(Laptm4b) deletion on hematopoietic stem/progenitor cells (HSPCs) homeostasis in mice. METHODS: The hematopoietic system specific Laptm4b-deficient mice were constructed. The number and proportion of HSPCs (LSK, LT, ST, MPP, etc) in Laptm4b-deficient mice were analyzed by flow cytometry. Single SLAM-HSC cell was sorted by flow sorter and cultured in vitro to measure the effect of Laptm4b deletion on the colony forming ability of hematopoietic stem cells (HSCs). The effect of Laptm4b-deficient on the reconstitution ability of HSCs in mice was detected by competitive transplantation experiment of SLAM-HSC cells. RESULTS: Laptm4b deficiency could moderately upregulate the proportion of T cells in the peripheral blood of the mice, but showed no significant effect on the proportion and number of HSPCs. Laptm4b deletion showed no effect on the reconstruction ability of HSCs after competitive transplantation, but it could inhibit the colony formation of HSCs in vitro. CONCLUSION: LAPTM4B may play a role in HSCs under the proliferation stress. Laptm4b-deficient in mice hematopoietic system showed no significant effect on the HSPCs homeostasis maintenance and reconstruction ability.

Evaluation of fronto-orbital reconstruction surgery for the treatment of metopic synostosis in Chinese population.

PURPOSE: To evaluate the efficacy of fronto-orbit reconstruction surgery on pediatric metopic synostosis via an image-based 3D reconstruction in Chinese population. METHODS: Thirty pediatric metopic synostosis patients who received fronto-orbital reconstruction surgery in the Children's Hospital of Nanjing Medical University, Department of Neurosurgery, from January 2007 to December 2018 were analyzed in the study. Here we use the Mimics 20.0 software to reconstruct patients' cranial thin-section CT scan images from pre- and post-operation and control groups. Then the data of intracranial volume, frontal volume, orbital hypertelorism, ECA, ZF, and ORA were analyzed using the paired t-test or Wilcoxon matched-pairs signed-ranks test. RESULTS: The age of these patients was 15.83 ± 16.12 months. After surgery, the mean frontal volume was enlarged from 92.75 ± 26.97 to 138.62 ± 47.97 cm3 (P < 0.0001), and the intracranial volume was enhanced from 976.87 ± 230.83 to 1059.44 ± 217.98 cm3 (P < 0.0001). In the meantime, the ECA was changed from 108.02 ± 8.17 to 134 ± 5.59° (P < 0.0001). In line with the alteration of the parameters mentioned above, the head shapes in all patients were also significantly improved after the surgery with no obvious complications. CONCLUSION: Fronto-orbit reconstruction surgery is a safe and effective treatment for pediatric metopic synostosis. Computer-aided 3D reconstruction could serve as a quantitative strategy to evaluate the efficacy of craniofacial surgery.

Total Cranial Reconstruction for the Treatment of Sagittal Craniosynostosis in Children.

OBJECTIVE: To study the effect of total cranial reconstruction for sagittal synostosis (scaphocephaly) deformity in Chinese children. METHODS: A retrospective analysis was performed involving 23 children with isolated non-syndromic sagittal synostosis who were treated by total calvarial vault remodeling after 1 year of age from May 2015 to June 2019 in the Department of Neurosurgery, Children's Hospital of Nanjing Medical University. The authors reconstruct patients' pre- and post-operative cranial thin-section CT scan images and those of the control group. The cephalic index (traditional, normative), intracranial volume, horizontal point of maximum width (H-PMW), vertical point of maximum width (V-PMW), frontal to head height ratio and occipital to head height ratio data were analyzed using a paired t test or Wilcoxon signed-rank test. RESULTS: Twenty-three patients met the inclusion criteria, including 19 males and 4 females. The ratio of males to females was 4.7:1. All patients underwent total cranial reconstruction. The average age was 26.52 months (13-48 months), the average operation time was 214.13 minutes (150-265 minutes), and the average amount of suspended erythrocytes was 200 ml (100-400 ml). The cranial morphology of all patients improved significantly after the operation. The traditional cephalic index (pre-operative: 0.70 (0.04); post-operative: 0.78 (0.02)) and normative cephalic index (pre-operative: 0.68 (0.03); post-operative: 0.77 (0.02)) were significantly increased (P < 0.0001). The mean horizontal point of maximum width improved from 0.54 to 0.56 (P = 0.0043), the mean vertical point of maximum width decreased from 0.59 to 0.54 (P = 0.0006), the frontal height decreased from 0.89 to 0.77 (P < 0.0001), and the occipital height improved from 0.78 to 0.88 (P < 0.0001). The intracranial volume increased from 1287.35 to 1426.90 cm3 (P < 0.0001). All of the children had a good skull shape and no recurrence of deformity. CONCLUSIONS: Total calvarial reconstruction can effectively correct scaphocephaly in Chinese children, expand cranial volume, reduce cranial height, shorten fronto-occipital diameters and enlarge biparietal diameters.

RUNX2 mutation impairs osteogenic differentiation of dental follicle cells.

OBJECTIVES: Cleidocranial dysplasia (CCD), mainly caused by RUNX2 mutation, is a dominantly inherited skeletal disorder with many dental abnormalities, characterized by delayed permanent tooth eruption. In this study, we explored a novel RUNX2 mutation and the effect of RUNX2 mutation on osteogenic differentiation of dental follicle cells (DFCs). DESIGN: A CCD patient with typical clinical features was involved in this study. Conservation and secondary structural analysis of the RUNX2 mutation was first performed. Then DFCs that stably expressing wild-type or mutant RUNX2 were established using lentiviruses. Cell Counting Kit 8 (CCK8) assays were performed to test the proliferation of DFCs. Measurement of alkaline phosphatase (ALP) activity, ALP staining, alizarin red staining and determination of osteoblast-specific genes expression were performed to assess osteogenic capacity of DFCs. RESULTS: A missense mutation (c.674 G > T, p. R225 L) of RUNX2 gene was identified in the CCD patient. Conservation and secondary structural analysis revealed that the mutation was located in highly conserved Runt domain and altered secondary structure of RUNX2. CCK8 assays showed that mutant RUNX2 increased the proliferation rate of DFCs compared to wild-type RUNX2. ALP activity, ALP staining and alizarin red staining results indicated that mutant RUNX2 decreased the mineralization ability of DFCs. In addition, mutant RUNX2 significantly down-regulated the expression of osteoblast-associated genes. CONCLUSIONS: RUNX2 mutation can reduce the osteogenic capacity of DFCs by inhibiting osteoblast-associated genes and then affecting bone formation, which participates in bone remodeling during tooth eruption. These effects may be partly responsible for the defects in permanent tooth eruption of CCD patients.

Ubiquitin-specific protease 22 promotes the proliferation, migration and invasion of glioma cells.

Ubiquitin-specific protease 22 (USP22), as one of the 11 death-from-cancer signature genes, presented high expression in a variety of tumors. Previous studies showed that USP22 played a significant role in cell-cycle, oncogenesis, clinicopathology and survival. Our studies have presented USP22 was over-expressed in glioma tissue and the patients with high expression of USP22 had a poor survival than that with low expression of USP22. However, the concrete effect of USP22 on biological behavior in glioma cells has been rarely reported. The study aimed to clear the effect of USP22 on cell proliferation, migration and invasion in glioma. Using siRNA, USP22 was knocked down in U251 and U87 glioma cells and successful transfection effect was validated. Cell proliferation, migration and invasion were observed by the methods of EdU, Wound healing and Transwell assay, separately. At the same time, the expression of MMP2 was detected by Gelatin zymography after transfecting siRNAs. After the knockdown of USP22 by siRNA, the abilities of glioma cell proliferation, migration and invasion were decreased, accompanying, the expression of MMP2 was also decreased. We drew a conclusion that USP22 could increase the abilities of proliferation, migration and invasion of glioma cells, and promote the growth and development of glioma.

RUNX2 mutation reduces osteogenic differentiation of dental follicle cells in cleidocranial dysplasia.

Disturbed permanent tooth eruption is common in cleidocranial dysplasia (CCD), a skeletal disorder caused by heterozygous mutation of RUNX2, but the mechanism underlying is still unclear. As it is well known that dental follicle cells (DFCs) play a critical role in tooth eruption, the changed biological characteristics of DFCs might give rise to disturbance of permanent tooth eruption in CCD patients. Thus, primary DFCs from one CCD patient and normal controls were collected to investigate the effect of RUNX2 mutation on the bone remodeling activity of DFCs and explore the mechanism of impaired permanent tooth eruption in this disease. Conservation and secondary structure analysis revealed that the RUNX2 mutation (c.514delT, p.172fs) found in the present CCD patient was located in the highly conserved RUNT domain and converted the structure of RUNX2. After osteogenic induction, we found that the mineralised capacity of DFCs and the expression of osteoblast-related genes, including RUNX2, ALP, OSX, OCN and Col Iα1, in DFCs was severely interfered by the RUNX2 mutation found in CCD patients. To investigate whether the osteogenic deficiency of DFCs from the CCD patient can be rescued by RUNX2 restoration, we performed 'rescue' experiments. Surprisingly, the osteogenic deficiency and the abnormal expression of osteoblast-associated genes in DFCs from the CCD patient were almost rescued by overexpression of wild-type RUNX2 using lentivirus. All these findings indicate that RUNX2 mutation can reduce the osteogenic capacity of DFCs through inhibiting osteoblast-associated genes, thereby disturbing alveolar bone formation, which serves as a motive force for tooth eruption. This effect may provide valuable explanations and implications for the mechanism of delayed permanent tooth eruption in CCD patients.

Abnormal bone remodelling activity of dental follicle cells from a cleidocranial dysplasia patient.

OBJECTIVES: To explore the role of dental follicle cells (DFCs) with a novel cleidocranial dysplasia (CCD) causative gene RUNX2 mutation (DFCsRUNX2+/m ) in delayed permanent tooth eruption. MATERIALS AND METHODS: A CCD patient with typical clinical features was involved in this study. DFCsRUNX2+/m were cultured and DNA was extracted for RUNX2 mutation screening. Measurements of cell proliferation, alkaline phosphatase (ALP) activity, alizarin red staining and osteoblast-specific genes expression were performed to assess osteogenesis of DFCsRUNX2+/m . Co-culture of DFCs and peripheral blood mononuclear cells (PBMCs), followed tartrate-resistant acid phosphatase (TRAP) staining, real-time PCR and western blot were performed to evaluate osteoclast-inductive capacity of DFCsRUNX2+/m . RESULTS: A missense RUNX2 mutation (c. 557G>C) was found in DFCsRUNX2+/m from the CCD patient. Compared with normal controls, this mutation did not affect the proliferation of DFCsRUNX2+/m , but down-regulated the expression of osteogenesis-related genes, leading to a decrease in ALP activity and mineralisation. Co-culture results showed that DFCsRUNX2+/m reduced the formation of TRAP+ multinucleated cells and the expression of osteoclastogenesis-associated genes. Furthermore, the mutation reduced the ratio of RANKL/OPG in DFCsRUNX2+/m . CONCLUSIONS: DFCsRUNX2+/m disturbs bone remodelling activity during tooth eruption through RANK/RANKL/OPG signalling pathway and may thus be responsible for impaired permanent tooth eruption in CCD patients.

Expression of WW domain-containing protein 2 is correlated with pathological grade and recurrence of glioma.

OBJECTIVE: WW domain-containing protein 2 (WWP2) is an E3 ubiquitin ligase, which belongs to the NEDD4-like protein family. Recently, it is reported to play a key role in tumorigenesis and development of tumors such as prostate and lung cancer. However, there has been not related report on glioma until now. The aim of this study is to detect the expression of WWP2 and analyze its correlation to the pathological grade and tumor recurrence in patients with glioma. MATERIALS AND METHODS: Western blot and immunohistochemistry were separately used to detect the expression of WWP2 protein in 31 brain glioma tissue samples and 80 brain glioma paraffin specimens. The method of Kaplan-Meier was used to analyze the correlation between the WWP2 expression and glioma recurrence. RESULTS: The protein expression level of WWP2 in glioma tissue was significantly higher than that in nontumorous brain tissue (P < 0.05), and the protein expression level of WWP2 in high-grade glioma (Grade III-IV) was significantly higher than that in low-grade glioma (Grade I-II) (P < 0.05). Kaplan-Meier analysis indicated that the patients with high WWP2 expression had significantly shorter tumor recurrence time than the patients with low WWP2 expression (P < 0.05). CONCLUSION: Our study suggests that WWP2 may play a role in the genesis and development of glioma; it may be a potential biomarker to predict pathological grade and tumor recurrence in patients with glioma.

ß-transducin repeat-containing E3 ubiquitin protein ligase inhibits migration, invasion and proliferation of glioma cells.

ß-transducin repeat-containing E3 ubiquitin protein ligase (ß-TrCP) serves as the substrate recognition subunit for the Skp1-Cullin1-F-box protein E3 ubiquitin ligase, which recognizes the double phosphorylated DSG (X)2+nS destruction motif in various substrates that are essential for numerous aspects of tumorigenesis and regulates several important signaling pathways. However, the biological significance of ß-TrCP in glioma progression remains largely unknown. A previous study by the authors demonstrated that the levels of ß-TrCP protein expression in brain glioma tissues were significantly lower compared with non-tumorous tissues and that higher grades of gliomas exhibited lower levels of ß-TrCP expression in comparison with lower glioma grades. In addition, low ß-TrCP expression was associated with poor prognosis in patients with glioma. Subsequently, the present study aimed to investigate the effect of ß-TrCP on migratory, invasive and proliferative abilities of glioma cells. ß-TrCP plasmids were transfected into cultured U251 and U87 glioma cells, and changes in migration, invasion and proliferation were analyzed using wound healing, Transwell and EdU assays. It was identified that the overexpression of ß-TrCP inhibited migration, invasion and proliferation in glioma cells. In summary, these results indicate that ß-TrCP may serve a protective role against the progression of glioma by suppressing cell migration, invasion and proliferation. The potential mechanism of ß-TrCP I glioma cells requires additional investigation.

Analysis of novel RUNX2 mutations in Chinese patients with cleidocranial dysplasia.

Cleidocranial dysplasia (CCD) is an autosomal dominant inheritable skeletal disorder characterized by cranial dysplasia, clavicle hypoplasia and dental abnormalities. This disease is mainly caused by heterozygous mutations in RUNX2, a gene that encodes an osteoblast-specific transcription factor. In the present study, mutational analyses of RUNX2 gene were performed on four unrelated Chinese patients with CCD. Four different RUNX2 mutations were detected in these patients, including one nonsense mutation (c.199C>T p.Q67X) and three missense mutations (c.338T>G p.L113R, c.557G>C p.R186T and c.673C>T p.R225W). Among them, two mutations (c.199C>T p.Q67X and c.557G>C p.R186T) were novel and the other two had been reported in previous literatures. Except for Q67X mutation located in the Q/A domain, other three mutations were clustered within the highly conserved Runt domain. Green fluorescent protein (GFP) and RUNX2 fusion protein analyses in vitro showed that nuclear accumulation of RUNX2 protein was disturbed by Q67X mutation, while the other two mutations (c.338T>G p.L113R and c.557G>C p.R186T) had no effects on the subcellular distribution of RUNX2. Luciferase reporter assay demonstrated that all the three novel RUNX2 mutations significantly reduced the transactivation activity of RUNX2 on osteocalcin promoter. Our findings enrich the evidence of molecular genetics that the mutations of RUNX2 gene are responsible for CCD.

Expression of ß-transducin repeat-containing E3 ubiquitin protein ligase in human glioma and its correlation with prognosis.

ß-transducin repeat-containing E3 ubiquitin protein ligase (ß-TrCP) targets a number of substrates essential for specific aspects of tumorigenesis. In addition, ß-TrCP regulates various important signaling pathways. As ß-TrCP is involved in regulating the ubiquitination and degradation of multiple oncogenes and tumor suppressors, the function of ß-TrCP varies between cancer types. At present, the association between ß-TrCP expression and clinicopathological factors in glioma is unknown. Therefore, the current study used western blotting and immunohistochemistry to investigate the expression of ß-TrCP protein in glioma tissue specimens. It was identified that ß-TrCP protein expression levels were significantly lower in glioma compared with non-tumorous human brain tissues. Furthermore, the higher the grade of glioma, the lower the level of ß-TrCP expression. Kaplan-Meier analysis demonstrated that patients with low ß-TrCP expression experienced significantly worse overall survival compared with patients with high ß-TrCP expression. The results indicate that downregulation of ß-TrCP may be associated with poor survival in patients with glioma. Together, the current data indicates that ß-TrCP may be applied as a useful indicator of glioma prognosis and may serve as an anticancer therapeutic target for glioma, however further investigation is required.