AIM: To investigate the clinicopathologic features of patients with extra-gastrointestinal stromal tumors (EGISTs) in South Korea.
METHODS: A total of 51 patients with an EGIST were identified. The clinicopathologic features, including sex, age, location, tumor size, histology, mitotic rate, immunohistochemical features, genetic status and survival data, were analyzed.
RESULTS: The median age was 55 years (range: 29-80 years), and male:female ratio was 1:1.04. The most common site was in the mesentery (n = 15) followed by the retroperitoneum (n = 13) and omentum (n = 8). The median tumor size was 9.0 cm (range: 2.6-30.0 cm) and the median mitotic rate was 5.0/50HPF. (1/50 - 185/50). KIT was analyzed in 16, which revealed 10 cases with wild-type KIT and 6 cases with an exon 11 mutation. Among 51 patients, 31 patients had undergone surgery, and 10 had unresectable disease and had taken palliative imatinib, which resulted in 22.7 mo of progression-free survival. Of the patients who had undergone surgery, 18 did not take adjuvant imatinib, and 8 of these were categorized as “high risk” according to the risk criteria. However, the relapse-free survival was not different (P = 0.157) between two groups.
CONCLUSION: Because the biologic behaviors of GISTs differ according to the location of the tumor, a more stratified strategy is required for managing EGISTs including incorporation of molecular features.
Gastrointestinal stromal tumor; Survival; Imatinib; Risk factor; Prognostic factor
To investigate the effects of age and sex on the relationship between socioeconomic status (SES) and the prevalence and control status of diabetes mellitus (DM) in Korean adults.
Data came from 16,175 adults (6,951 men and 9,227 women) over the age of 30 who participated in the 2008-2010 Korea National Health and Nutrition Examination Survey. SES was measured by household income or education level. The adjusted odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) for the prevalence or control status of diabetes were calculated using multiple logistic regression analyses across household income quartiles and education levels.
The household income-DM and education level-DM relationships were significant in younger age groups for both men and women. The adjusted ORs and 95% CI for diabetes were 1.51 (0.97, 2.34) and 2.28 (1.29, 4.02) for the lowest vs. highest quartiles of household income and education level, respectively, in women younger than 65 years of age (both P for linear trend < 0.05 with Bonferroni adjustment). The adjusted OR and 95% CI for diabetes was 2.28 (1.53, 3.39) for the lowest vs. highest quartile of household income in men younger than 65 (P for linear trend < 0.05 with Bonferroni adjustment). However, in men and women older than 65, no associations were found between SES and the prevalence of DM. No significant association between SES and the status of glycemic control was detected.
We found age- and sex-specific differences in the relationship of household income and education with the prevalence of DM in Korea. DM preventive care is needed for groups with a low SES, particularly in young or middle-aged populations.
Background. We performed a systematic review and meta-analysis to study the association between serum endostatin levels and gastric cancer (GC) progression. Method. We searched the MEDLINE, Science Citation Index, Cochrane Library, PubMed, Embase, Current Contents Index, and several Chinese databases for published studies relevant to our study topic. Carefully selected studies were pooled and SMD and its corresponding 95% CI were calculated. Version 12.0 STATA software was used for statistical analysis. Results. Serum endostatin levels were analyzed in 12 case-control studies (736 GC patients and 350 controls). Significant differences in serum endostatin levels were observed between GC patients and the healthy controls (SMD = 1.418, 95% CI = 1.079~1.757, P < 0.001). Importantly, significantly lower levels of serum endostatin were found in I-II grade patients compared to those with III-IV grade tumors (P < 0.001). Further, higher serum endostatin levels were observed in the LN invasion-positive GC subjects in comparison with LN invasion-negative subjects (P < 0.001). Conclusion. Patients with GC exhibited elevated levels of serum endostatin than controls and its level showed a statistical correlation with the more aggressive type of GC, exhibiting invasion and LN metastasis. Thus, serum levels of endostatin being a useful prognostic biomarker for GC patients warrants further investigation.
Raf-1 kinase inhibitory protein (RKIP), an endogenous inhibitor of the extracellular signal-regulated kinase (ERK) pathway, suppresses metastasis in a number of cancer types, including colorectal carcinoma (CRC); thus, RKIP downregulation significantly contributes to CRC invasiveness and metastatic potential. However, our previous study demonstrated that RKIP-positive tumors in CRC patients are predictive of hepatic colorectal metastases (HCMs). Based on the previous finding that the ERK pathway can be activated independently of RKIP, we hypothesized that RKIP-expressing HCMs may express significant levels of phosphorylated ERK (pERK). Thus, the present study evaluated the expression of RKIP and pERK in 68 HCM tissue samples using immunohistochemistry. RKIP expression was positive in 22 (32.4%) of the 68 samples, seven (31.8%) of which exhibited nuclear pERK immunoreactivity exclusively at the invasive tumor front. Furthermore, pERK expression at the invasive front was significantly associated with recurrent HCM following hepatic resection, and pERK expression observed at the invasive front of RKIP-expressing HCMs indicated that the activation of the ERK pathway may also be involved in the invasive process of these tumors, despite the presence of RKIP. A strong association between pERK expression and the presence of recurrent HCM may indicate that the ERK pathway is important in the metastatic recurrence of RKIP-positive HCM.
extracellular signal-regulated kinase; invasive tumor front; Raf kinase inhibitor protein; colorectal carcinoma; liver; metastasis
Striatal-enriched tyrosine phosphatase (STEP) is an important regulator of neuronal synaptic plasticity, and its abnormal level or activity contributes to cognitive disorders. One crucial downstream effector and direct substrate of STEP is extracellular signal-regulated protein kinase (ERK), which has important functions in spine stabilisation and action potential transmission. The inhibition of STEP activity toward phospho-ERK has the potential to treat neuronal diseases, but the detailed mechanism underlying the dephosphorylation of phospho-ERK by STEP is not known. Therefore, we examined STEP activity toward pNPP, phospho-tyrosine-containing peptides, and the full-length phospho-ERK protein using STEP mutants with different structural features. STEP was found to be a highly efficient ERK tyrosine phosphatase that required both its N-terminal regulatory region and key residues in its active site. Specifically, both KIM and KIS of STEP were required for ERK interaction. In addition to the N-terminal KIS region, S245, hydrophobic residues L249/L251, and basic residues R242/R243 located in the KIM region were important in controlling STEP activity toward phospho-ERK. Further kinetic experiments revealed subtle structural differences between STEP and HePTP that affected the interactions of their KIMs with ERK. Moreover, STEP recognised specific positions of a phospho-ERK peptide sequence through its active site, and the contact of STEP F311 with phospho-ERK V205 and T207 were crucial interactions. Taken together, our results not only provide the information for interactions between ERK and STEP, but will also help in the development of specific strategies to target STEP-ERK recognition, which could serve as a potential therapy for neurological disorders.
ERK; phosphorylation; phosphatase; synaptic plasticity; Striatal enriched tyrosine phosphatases (STEP); neurological disorders
A novel delayed anaphylactic reaction to red meat, associated with tick bites and IgE antibodies against galactose-α-1, 3-galactose (α-gal), was reported in 2009 in the US, Australia and Europe. In this case, serum specific IgE to galactose-α-1, 3-galactose (>100 kU/L) and IgE to multiple non-primate mammalian proteins were positive. However, the pathogenesis of this disease remains unclear. We report the first case in Asia of delayed anaphylactic reaction to red meat, which was induced by bites from the hard tick, Hematophagous ixodidae. We confirmed the increased concentration of IgE reactive epitopes in non-primate mammalian organs, which may be rich in α-gal proteins in lymphatic and endothelial tissues. All confirmed ticks associated with this disorder in the literature and in our case belonged to the hard tick family. We hypothesize that hard tick saliva is enriched with blood-type substances, such as oligosaccharides, from the non-primate mammal victim's blood after days to weeks of blood sucking, which sensitizes humans through the injection route while blood sucking.
Food allergy; anaphylaxis; red meat allergy; tick
C-reactive protein (CRP) is a serologic activity marker in Crohn’s disease (CD), but it may be less useful in evaluating CD activity in ileal CD patients. We aimed to investigate the usefulness of CRP as a disease activity marker in CD according to disease location.
Korean CD patients in a single hospital were evaluated. Factors associated with elevated CRP concentration at the time of diagnosis of CD and the association between the physician’s prediction regarding upcoming surgery and the sites of the lesions directly related to surgery were analyzed.
Of 435 CD patients, 25.7%, 6.9%, and 67.4% had ileal, colonic, and ileocolonic CD, respectively. Multivariate analysis revealed that an elevated erythrocyte sedimentation rate, reduced serum albumin, CD activity index (CDAI) >220, and ileocolonic/colonic location were associated with an elevated CRP level and that the CRP level was significantly correlated with the CDAI in all CD patients (γ=0.466, p<0.01). However, the correlation coefficient was dependent on the location, with values of 0.395, 0.456, and 0.527 in patients with an ileal, ileocolonic, and colonic disease location, respectively. Surgery for ileal lesions was less predictable than surgery for ileocolonic or colonic lesions during follow-up.
CRP is less useful as a disease activity marker in patients with ileal CD than those with ileocolonic or colonic CD.
Crohn disease; C-reactive protein; Inflammation
This review aims to evaluate the effectiveness and safety of acupuncture for patients with postoperative pain after laparoscopic surgery.
Methods and analysis
We will search the following databases from their inception to October 2014: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), three Chinese databases (China National Knowledge Infrastructure (CNKI), the Chongqing VIP Chinese Science and Technology Periodical Database (VIP) and the Wanfang database), one Japanese database (Japan Science and Technology Information Aggregator, Electronic (J-STAGE)) and eight Korean databases (Korean Association of Medical Journal Edition, Korean Medical Database, Korean Studies Information Service System, National Discovery for Science Leaders, Database Periodical Information Academic, Korean National Assembly Digital Library, Oriental Medicine Advanced Searching Integrated System and Korean Traditional Knowledge Portal). All randomised controlled trials of acupuncture for postoperative pain after laparoscopic surgery will be considered for inclusion. The risk of bias and reporting quality will be assessed using the Cochrane risk of bias tool, the Consolidated Standards of Reporting Trials (CONSORT) and the revised STandards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA). The risk ratio for dichotomous data and mean difference or standard mean difference for continuous data will be calculated with 95% CIs.
The results of this review will be disseminated through peer-reviewed publication or conference presentation. Our findings will summarise the current evidence of acupuncture to treat postoperative pain after laparoscopic surgery, and may provide important guidance for acupuncture usage after laparoscopic surgery for clinicians and patients.
Trial registration number
PROSPERO 2014: CRD42014010825.
COMPLEMENTARY MEDICINE; SURGERY
The CRISPR/Cas9 system has recently emerged as a powerful tool for functional genomic studies in Drosophila melanogaster. However, sgRNA parameters affecting the specificity and efficiency of the system in flies are still not clear. Here, we found that off-target effects did not occur in regions of genomic DNA with three or more nucleotide mismatches to sgRNAs. Importantly, we document for the first time a strong positive correlation between mutagenesis efficiency and sgRNA GC content of the six protospacer adjacent motif-proximal nucleotides (PAMPNs). Furthermore, by injecting well-designed sgRNA plasmids at the optimal concentration we determined, we could efficiently generate mutations in four genes in one step. Finally, we generated null alleles of HP1a using optimized parameters through homology-directed repair, and achieved an overall mutagenesis rate significantly higher than previously reported. Our work presents the most comprehensive optimization of sgRNA and promises to vastly simplify CRISPR/Cas9 experiments in Drosophila.
CRISPR; Cas9; sgRNA; off-target; multiple mutants; homology-directed repair
The cadherin EGF LAG seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors (GPCRs), which are pivotal regulators of many biological processes such as neuronal/endocrine cell differentiation, vessel valve formation and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1-3) have large ecto-domains that form homophilic interactions and encompass more than 2,000 amino acids. Mutations in the ecto-domain or other gene locations of CELSRs are associated with neural tube defects (NTDs) and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR-targeted therapeutic reagents.
G Protein-Coupled Receptor (GPCR); Adhesion; CELSR; Development; Planar Cell Polarity (PCP)
Processing and managing radioactive waste is a great challenge worldwide as it is extremely difficult and costly; the radioactive species, cations or anions, leaked into the environment are a serious threat to the health of present and future generations. We report layered potassium niobate (K4Nb6O17) nanolamina as adsorbent to remove toxic Sr2+, Ba2+ and Cs+ cations from wastewater. The results show that K4Nb6O17 nanolamina can permanently confine the toxic cations within the interlayer spacing via a considerable deformation of the metastable layered structure during the ion exchange process. At the same time, the nanolaminar adsorbent exhibits prompt adsorption kinetics, high adsorption capacity and selectivity, and superior acid resistance. These merits make it be a promising material as ion exchanger for the removal of radioactive cations from wastewater.
Spontaneous HBeAg seroconversion occurs frequently in the immune reactive phase in HBeAg-positive chronic hepatitis B (CHB). Therefore, observation for 3-6 months before commencing antiviral therapy is recommended in patients with alanine aminotransferase (ALT) levels that exceed twice the upper limit of normal (ULN). However, HBeAg seroconversion occurs infrequently in patients infected with hepatitis B virus (HBV) genotype C. The aim of the present study was to determine whether the waiting policy is necessary in endemic areas of HBV genotype C infection.
Ninety patients with HBeAg-positive CHB were followed prospectively without administering antiviral therapy for 6 months. Antiviral therapy was initiated promptly at any time if there was any evidence of biochemical (i.e., acute exacerbation of HBV infection or aggravation of jaundice) or symptomatic deterioration. After 6 months of observation, antiviral therapy was initiated according to the patient's ALT and HBV DNA levels.
Only one patient (1.1%) achieved spontaneous HBeAg seroconversion. Biochemical and symptomatic deterioration occurred before 6 months in 17 patients (18.9%) and 5 patients, respectively. High ALT and HBV DNA levels were both independent risk factors for biochemical deterioration. Of 15 patients with HBV DNA ≥5.1×107 IU/mL and ALT ≥5×ULN, biochemical deterioration occurred in 7 (46.7%), including 1 patient receiving liver transplantation due to liver failure.
Spontaneous HBeAg seroconversion in patients with HBeAg-positive CHB is rare within 6 months. Biochemical deterioration was common and may lead to liver failure. Immediate antiviral therapy should be considered, especially in patients with high ALT and HBV DNA levels in endemic areas of genotype C infection.
Hepatitis B virus, chronic hepatitis B; acute exacerbation of hepatitis B, HBV genotype
To evaluate the efficacy of radiofrequency ablation (RFA) in the treatment of loco-regional, recurrent, and well-differentiated thyroid carcinoma.
Materials and Methods
Thirty-five recurrent well-differentiated thyroid carcinomas (RTC) in 32 patients were treated with RFA, between March 2008 and October 2011. RTCs were detected by regular follow-up ultrasound and confirmed by biopsy. All patients had fewer than 3 RTCs in the neck and were at high surgical risk or refused to undergo repeated surgery. Average number of RFA sessions were 1.3 (range 1-3). Post-RFA biopsy and ultrasound were performed. The mean follow-up period was 30 months. Pre- and post-RFA serum thyroglobulin values were evaluated.
Thirty-one patients with 33 RTCs were treated with RFA only, whereas 1 patient with 2 RTCs was treated with RFA followed by surgery. At the last follow-up ultrasound, 31 (94%) of the 33 RTCs treated with RFA alone completely disappeared and the remaining 2 (6%) RTCs showed decreased volume. The largest diameter and volume of the 33 RTCs were markedly decreased by 93.2% (from 8.1 ± 3.4 mm to 0.6 ± 1.8 mm, p < 0.001) and 96.4% (from 173.9 ± 198.7 mm3 to 6.2 ± 27.9 mm3, p < 0.001), respectively. Twenty of the 21 RTCs evaluated with post-RFA biopsies (95%) were negative for malignancy. One (5%) showed remaining tumor that was removed surgically. The serum thyroglobulin was decreased in 19 of 26 patients (73%). Voice change developed immediately after RFA in 6 patients (19%) and was spontaneously recovered in 5 patients (83%).
Radiofrequency ablation can be effective in treating loco-regional, recurrent, and well-differentiated thyroid carcinoma in patients at high surgical risk.
Radiofrequency ablation; Recurrent thyroid cancer; Efficacy; Thyroid; Ultrasound
Hepatocellular carcinoma (HCC) is a complex disease with multiple underlying pathogenic mechanisms caused by a variety of etiologic factors. Emerging evidence showed that long non-coding RNAs (lncRNAs), with size larger than 200 nucleotides (nt), play important roles in various types of cancer development and progression. In recent years, some dysregulated lncRNAs in HCC have been revealed and roles for several of them in HCC have been characterized. All these findings point to the potential of lncRNAs as prospective novel therapeutic targets in HCC. In this review, we summarize known dysregulated lncRNAs in HCC, and review potential biological roles and underlying molecular mechanisms of lncRNAs in HCC. Additionally, we discussed prospects of lncRNAs as potential biomarker and therapeutic target for HCC. In conclusion, this paper will help us gain better understanding of molecular mechanisms by which lncRNAs perform their function in HCC and also provide general strategies and directions for future research.
long noncoding RNA; hepatocellular carcinoma; dysregulation; biological roles; molecular mechanism
Bronchiectasis and asthma are different in many respects, but some patients have both conditions. Studies assessing the effect of bronchiectasis on asthma exacerbation are rare. The aim of this study is to investigate the effect of bronchiectasis on asthma exacerbation.
We enrolled 2,270 asthma patients who were followed up in our hospital. Fifty patients had bronchiectasis and asthma. We selected fifty age- and sex-matched controls from the 2,220 asthma patients without bronchiectasis, and assessed asthma exacerbation and its severity based on the annual incidence of total asthma exacerbation, annual prevalence of steroid use, and frequency of emergency room visits and hospitalizations due to asthma exacerbation in each group.
Fifty patients (2.2%) had bronchiectasis and asthma. The annual incidence of asthma exacerbation was higher in patients with asthma and bronchiectasis than in patients with asthma alone (1.08±1.68 vs. 0.35±0.42, p=0.004). The annual prevalence of steroid use (0.9±1.54 vs. 0.26±0.36, p=0.006) and the frequency of emergency room visits (0.46±0.84 vs. 0.02±0.13, p=0.001) due to asthma exacerbation were also higher in patients with asthma and bronchiectasis than in patients with asthma alone.
Bronchiectasis is associated with difficult asthma control.
Bronchiectasis; Asthma; Disease Exacerbation
The aim of this study was to evaluate the Temperament and Character Inventory (TCI) scores of a sample of Korean patients with remitted depression who had attempted suicide and reported suicidal ideation and to compare their scores with those of remitted depressed patients without suicidal ideation. Adult depression patients who had completed 12 weeks of follow-up (N = 138) were divided into three groups: patients with a history of suicide attempts (N = 23); patients with current suicidal ideation (N = 59); and patients without current suicidal ideation (N = 56). After controlling for covariates, no significant differences were found among the three groups on any measure of temperament or character except self-directedness and self-transcendence. The self-transcendence scores of the lifetime suicide-attempt group were significantly higher compared with those of the suicidal-ideation group; post hoc analysis revealed that self-directedness was significantly lower in the suicide-attempt group compared with the non-suicidal group. The results from the present study suggest that remitted depression patients with a history of suicide attempts do not differ from non-attempters in temperament, but do differ in certain character traits.
Several recent studies have reported that the early use of infliximab (IFX) improves the prognosis of Crohn's disease (CD). However, no data are available from Asian populations, as the forementioned studies have all been conducted in Western countries. The aim of the current study was to evaluate the impact of early use of IFX on the prognosis of Korean patients with CD.
Patients with a diagnosis of CD established between July 1987 and January 2012 were investigated in 12 university hospitals in Korea. Because insurance coverage for IFX treatment began in August 2005, patients were assigned to either of 2 groups based on diagnosis date. The first group included patients diagnosed from July 1987 to December 2005, and the second from January 2006 to January 2012. We compared the cumulative probabilities of operation and reoperation between the two groups using the Kaplan-Meier method and a log-rank test.
Of the 721 patients investigated, 443 (61.4%) comprized the second group. Although the cumulative probabilities of immunosuppressant (P<0.001) and IFX use (P<0.001) after diagnosis were significantly higher in the second group, there were no significant differences in cumulative probabilities of operation (P=0.905) or reoperation (P=0.418) between two groups.
The early use of IFX did not reduce CD-related surgery requirements in Korean patients with CD. These study results suggest that the early use of IFX may have little impact on the clinical outcome of CD in Korean patients in the setting of a conventional step-up algorithm.
Crohn disease; Infliximab; Prognosis
AIM: To determine the existence of a potential relationship between the methylation state of the Vimentin gene and its prognostic value in pancreatic cancer.
METHODS: Sixty-four primary tumor specimens and normal tissues were collected consecutively from pancreatic cancer patients during surgery at Hangzhou First People’s Hospital and Affiliated Hospital of the Logistics University of the Chinese People’s Armed Police Force. DNA was extracted from the samples and subsequently quantitative methylation-specific polymerase chain reaction was used to detect the Vimentin methylation status of the samples. All of the patients were followed up to December 2012. χ2 test, Kaplan-Meier survival and Cox regression statistical models were used.
RESULTS: Out of 64 pancreatic cancer tissues, 21 were marked as Vimentin methylation-positive, and 43 were marked as Vimentin methylation-negative. The location of pancreatic carcinoma was related to the Vimentin methylation state. The pathological T staging (P < 0.001), adjuvant chemotherapy (P = 0.003) and the Vimentin methylation state (P = 0.037) were independent prognostic factors.
CONCLUSION: In our study, Vimentin methylation status can predict the prognosis of pancreatic cancer patients. However, additional experiments and clinical trials are needed to accurately validate this observation.
Vimentin; Methylation; Pancreatic carcinoma; Prognosis
The importance of ectoenzymes CD39 and CD73 in mediating adenosinergic immunosuppression has been recognized, but their roles in human malignant glioma–associated immunosuppression remain largely unknown.
In this study, the ectoenzyme characteristics of malignant glioma cells and infiltrating CD4+ T lymphocytes isolated from newly diagnosed malignant glioma patients were investigated. The ectoenzyme activities of both cell populations were determined by nucleotide hydrolysis assay. The immunosuppressive property of the CD39-CD73 synergic effect was evaluated via responder T-cell proliferation assay.
We observed that CD39−CD73+ glioma cells and infiltrating CD4+CD39highCD73low T lymphocytes exhibited 2 distinct but complementary ectoenzyme phenotypes, which were further verified by enzyme activity assay. The nucleotide hydrolysis cascade was incomplete unless CD39 derived from T lymphocytes and CD73 collaborated synergistically. We demonstrated that increased suppression of responder CD4+ T-cell proliferation suppression was induced by CD4+CD39+ T cells in the presence of CD73+ glioma cells, which could be alleviated by the CD39 inhibitor ARL67156, the CD73 inhibitor APCP, or the adenosine receptor A2aR antagonist SCH58261. In addition, survival analysis suggested that CD73 downregulation was a positive prognostic factor related to the extended disease-free survival of glioblastoma patients.
Our data indicate that glioma-derived CD73 contributes to local adenosine-mediated immunosuppression in synergy with CD39 from infiltrating CD4+CD39+ T lymphocytes, which could become a potential therapeutic target for treatment of malignant glioma and other immunosuppressive diseases.
CD39-CD73-adenosinergic immunosuppression; glioma microenvironment; infiltrating T lymphocytes; malignant glioma; synergic effect
The tyrosine phosphorylation barcode encoded in C-terminus of HER2 and its ubiquitination regulate diverse HER2 functions. PTPN18 was reported as a HER2 phosphatase; however, the exact mechanism by which it defines HER2 signaling is not fully understood. Here, we demonstrate that PTPN18 regulates HER2-mediated cellular functions through defining both its phosphorylation and ubiquitination barcodes. Enzymologic characterization and three crystal structures of PTPN18 in complex with HER2 phospho-peptides revealed the molecular basis for the recognition between PTPN18 and specific HER2 phosphorylation sites, which assumes two distinct conformations. Unique structural properties of PTPN18 contribute to the regulation of sub-cellular phosphorylation networks downstream of HER2, which are required for inhibition of HER2-mediated cell growth and migration. Whereas the catalytic domain of PTPN18 blocks lysosomal routing and delays the degradation of HER2 by dephosphorylation of HER2 on pY1112, the PEST domain of PTPN18 promotes K48-linked HER2 ubiquitination and its rapid destruction via the proteasome pathway and an HER2 negative feedback loop. In agreement with the negative regulatory role of PTPN18 in HER2 signaling, the HER2/PTPN18 ratio was correlated with breast cancer stage. Taken together, our study presents a structural basis for selective HER2 dephosphorylation, a previously uncharacterized mechanism for HER2 degradation and a novel function for the PTPN18 PEST domain. The new regulatory role of the PEST domain in the ubiquitination pathway will broaden our understanding of the functions of other important PEST domain-containing phosphatases, such as LYP and PTPN12.
phosphatase; receptor; ubiquitination; HER2; PTPN18; EGFR
Indigenous opportunistic bacteria on the interior of the Peyer’s patches play a key role in the development of the mucosal immune, but their population composition has been ignored. The present study was conducted to test the hypothesis that the changes in the composition of indigenous opportunistic bacteria in the Peyer’s patches are associated with obesity. C57BL/6J-male mice had been fed either a control diet or a high-fat diet. After 25 weeks, mice in high-fat diet exhibit either an obesity-prone (OP) or an obesity-resistant (OR) phenotype. Control diet group (CT) and OR group had a significant larger bacteria diversity than that in the OP group. Allobaculum and Lactobacillus were significantly decreased in high-fat diet induced OP mice compared with CT and OR mice, whereas Rhizobium and Lactococcus was significantly increased. The result of quantitative real-time PCR was consistent with that of 454 pyrosequencing. Significant correlations between mRNA expression of inflammation marks and the top 5 abundance genera bacteria on the interior of Peyer’s patches were observed by Pearson’s correlation analysis. Taken together, the indigenous opportunistic bacteria on the interior of Peyer’s patches plays a major role in the development of inflammation for an occurrence of obesity.
indigenous opportunistic bacteria; inflammation; obesity; Peyer’s patches; 454 pyrosequencing
The gaseous plant hormone ethylene regulates many aspects of plant growth, development and responses to the environment. Constitutive triple response 1 (CTR1) is a central regulator involved in the ethylene signal transduction pathway. To obtain a better understanding of this particular pathway in cucumber, the cDNA-encoding CTR1 (designated CsCTR1) was isolated from cucumber. A sequence alignment and phylogenetic analyses revealed that CsCTR1 has a high degree of homology with other plant CTR1 proteins. The ectopic expression of CsCTR1 in the Arabidopsis ctr1-1 mutant attenuates constitutive ethylene signaling of this mutant, suggesting that CsCTR1 indeed performs its function as negative regulator of the ethylene signaling pathway. CsCTR1 is constitutively expressed in all of the examined cucumber organs, including roots, stems, leaves, shoot apices, mature male and female flowers, as well as young fruits. CsCTR1 expression gradually declined during male flower development and increased during female flower development. Additionally, our results indicate that CsCTR1 can be induced in the roots, leaves and shoot apices by external ethylene. In conclusion, this study provides a basis for further studies on the role of CTR1 in the biological processes of cucumber and on the molecular mechanism of the cucumber ethylene signaling pathway.
Cucumis sativus; constitutive triple response 1 (CTR1); ectopic expression; ethylene signaling; expression analysis
Despite the crucial role of endothelial progenitor cells (EPCs) in vascular regeneration, the specific interactions between EPCs and hematopoietic cells remain unclear.
In EPC colony forming assays, we first demonstrated that the formation of EPC colonies was drastically increased in the coculture of CD34+ and CD34− cells, and determined the optimal concentrations of CD34+ cells and CD34− cells for spindle-shaped EPC differentiation.
Functionally, the coculture of CD34+ and CD34− cells resulted in a significant enhancement of adhesion, tube formation, and migration capacity compared with culture of CD34+ cells alone. Furthermore, blood flow recovery and capillary formation were remarkably increased by the coculture of CD34+ and CD34− cells in a murine hind-limb ischemia model. To elucidate further the role of hematopoietic cells in EPC differentiation, we isolated different populations of hematopoietic cells. T lymphocytes (CD3+) markedly accelerated the early EPC status of CD34+ cells, while macrophages (CD11b+) or megakaryocytes (CD41+) specifically promoted large EPC colonies.
Our results suggest that specific populations of hematopoietic cells play a role in the EPC differentiation of CD34+ cells, a finding that may aid in the development of a novel cell therapy strategy to overcome the quantitative and qualitative limitations of EPC therapy.
Recent studies of the Cas9/sgRNA system in Drosophila melanogaster genome editing have opened new opportunities to generate site-specific mutant collections in a high-throughput manner. However, off-target effects of the system are still a major concern when analyzing mutant phenotypes. Mutations converting Cas9 to a DNA nickase have great potential for reducing off-target effects in vitro. Here, we demonstrated that injection of two plasmids encoding neighboring offset sgRNAs into transgenic Cas9D10A nickase flies efficiently produces heritable indel mutants. We then determined the effective distance between the two sgRNA targets and their orientations that affected the ability of the sgRNA pairs to generate mutations when expressed in the transgenic nickase flies. Interestingly, Cas9 nickase greatly reduces the ability to generate mutants with one sgRNA, suggesting that the application of Cas9 nickase and sgRNA pairs can almost avoid off-target effects when generating indel mutants. Finally, a defined piwi mutant allele is generated with this system through homology-directed repair. However, Cas9D10A is not as effective as Cas9 in replacing the entire coding sequence of piwi with two sgRNAs.
CRISPR; Cas9; off-target; nickase; piwi