Novel potential urinary biomarkers for effective diagnosis and prognostic evaluation of high-grade bladder cancer.

Background: High-grade bladder cancer (HGBC) has a higher malignant potential, recurrence and progression rate compared to low-grade phenotype. Its early symptoms are often vague, making non-invasive diagnosis using urinary biomarkers a promising approach. Methods: The gene expression data from urine samples of patients with HGBC was extracted from the GSE68020 dataset. The clinical information and gene expression data in tumor tissues of HGBC patients were obtained from The Cancer Genome Atlas (TCGA) database. Multivariate Cox analysis was used to predict the optimal risk model. The protein-protein interaction (PPI) analysis was performed via the Search Tool for the Retrieval of Interacting Genes (STRING) database and visualized using Cytoscape. Overall survival (OS) was evaluated in the Gene Expression Profiling Interactive Analysis (GEPIA) online platform. Competing endogenous RNA (ceRNA) network was also visualized using Cytoscape. The expression levels of specific genes were assessed through quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Moreover, co-expressed genes and potential biological functions related to specific genes were explored based on the Cancer Cell Line Encyclopedia (CCLE) database. Results: A total of 560 differentially expressed genes (DEGs) were identified when comparing the urine sediment samples from HGBC patients with the benign ones. Using these urinary DEGs and the clinical information of HGBC patients, we developed an optimal risk model consisting of eight genes to predict the patient outcome. By integrating the node degree values in the PPI network with the expression changes in both urine and tissue samples, eighteen hub genes were selected out. Among them, DKC1 and SNRPG had the most prominent comprehensive values, and EFTUD2, LOR and EBNA1BP2 were relevant to a worse OS in bladder cancer patients. The ceRNA network of hub genes indicated that DKC1 may be directly regulated by miR-150 in HGBC. The upregulation of both SNRPG and DKC1 were detected in HGBC cells, which were also observed in various tumor tissues and malignant cell lines, displaying high correlations with other hub genes. Conclusions: Our study may provide theoretical basis for the development of effective non-invasive detection and treatment strategies, and further research is necessary to explore the clinical applications of these findings.

Hsa_circ_0016070/micro-340-5p Axis Accelerates Pulmonary Arterial Hypertension Progression by Upregulating TWIST1 Transcription Via TCF4/ß-Catenin Complex.

Background Hypoxia is considered a major leading cause of pulmonary hypertension (PH). In this study, the roles and molecular mechanism of circ_0016070 in PH were studied. Methods and Results The expression of circ_0016070 in serum samples, human pulmonary artery smooth muscle cells and hypoxia/monocrotaline-treated rats was determined by real-time quantitative polymerase chain reaction. Cell viability, migration, and apoptosis were analyzed by Cell Counting Kit-8, wound healing, flow cytometry, and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assays, respectively. The molecular interactions were validated using RNA immunoprecipitation, chromatin immunoprecipitation, and dual luciferase reporter assays. The levels of phenotype switch-related proteins were evaluated by Western blot and immunohistochemistry. The pathological characteristics were assessed using hematoxylin and eosin staining. circ_0016070 was highly expressed in the serum samples, hypoxia-induced pulmonary artery smooth muscle cells and pulmonary arterial tissues of PH rats. Downregulation of circ_0016070 ameliorated the excessive proliferation, migration, vascular remodeling, and phenotypic transformation but enhanced cell apoptosis in the PH rat model. In addition, micro (miR)-340-5p was verified as a direct target of circ_0016070 and negatively regulated TCF4 (transcription factor 4) expression. TCF4 formed a transcriptional complex with ß-catenin to activate TWIST1 (Twist family bHLH transcription factor 1) expression. Functional rescue experiments showed that neither miR-340-5p inhibition nor TWIST1 or TCF4 upregulation significantly impeded the biological roles of circ_0010670 silencing in PH. Conclusions These results uncovered a novel mechanism by which circ_0016070 play as a competing endogenouse RNA of miR-340-5p to aggravate PH progression by promoting TCF4/ß-catenin/TWIST1 complex, which may provide potential therapeutic targets for PH.

The MFF-SIRT1/3 axis, regulated by miR-340-5p, restores mitochondrial homeostasis of hypoxia-induced pulmonary artery smooth muscle cells.

Mitochondrial dynamics and quality control play a central role in the maintenance of the proliferation-apoptosis balance, which is closely related to the progression of pulmonary arterial hypertension (PAH). However, the exact mechanism of this balance remains unknown. Pulmonary artery smooth muscle cells (PASMCs) were cultured in hypoxia condition for constructing a PAH model in vitro. The expression of genes and proteins were determined by qRT-PCR and western bolt assays. Cell proliferation-apoptosis balance were tested by MTT, EdU and TUNEL assays. The mitochondrial functions were assessed by flow cytometry, JC-1, Mito tracker red staining, and corresponding kits. Besides, the molecular interaction was validated by dual-luciferase reporter assay. MFF was overexpressed in hypoxia-treated PAMSCs. Knockdown of MFF significantly repressed the excessive proliferation but enhanced cell apoptosis in hypoxia-treated PAMSCs. Moreover, MFF silencing improved mitochondrial function of hypoxia-treated PAMSCs by increasing ATP production and decreasing ROS release and mitochondrial fission. Mechanistically, MFF was a directly target of miR-340-5p, and could negatively regulate SIRT1/3 expression. Subsequently, functional rescue assays showed that the biological effects of MFF in hypoxia-treated PAMSCs were negatively regulated by miR-340-5p and depended on the regulation on SIRT1/3 pathway. These results provided evidences that miR-340-5p regulated MFF-SIRT1/3 axis to improve mitochondrial homeostasis and proliferation-apoptosis imbalance of hypoxia-treated PAMSCs, which provided a theoretical basis for the prevention and treatment of PAH.

Fis1 phosphorylation by Met promotes mitochondrial fission and hepatocellular carcinoma metastasis.

Met tyrosine kinase, a receptor for a hepatocyte growth factor (HGF), plays a critical role in tumor growth, metastasis, and drug resistance. Mitochondria are highly dynamic and undergo fission and fusion to maintain a functional mitochondrial network. Dysregulated mitochondrial dynamics are responsible for the progression and metastasis of many cancers. Here, using structured illumination microscopy (SIM) and high spatial and temporal resolution live cell imaging, we identified mitochondrial trafficking of receptor tyrosine kinase Met. The contacts between activated Met kinase and mitochondria formed dramatically, and an intact HGF/Met axis was necessary for dysregulated mitochondrial fission and cancer cell movements. Mechanically, we found that Met directly phosphorylated outer mitochondrial membrane protein Fis1 at Tyr38 (Fis1 pY38). Fis1 pY38 promoted mitochondrial fission by recruiting the mitochondrial fission GTPase dynamin-related protein-1 (Drp1) to mitochondria. Fragmented mitochondria fueled actin filament remodeling and lamellipodia or invadopodia formation to facilitate cell metastasis in hepatocellular carcinoma (HCC) cells both in vitro and in vivo. These findings reveal a novel and noncanonical pathway of Met receptor tyrosine kinase in the regulation of mitochondrial activities, which may provide a therapeutic target for metastatic HCC.

Epithelioid sarcoma of the parapharyngeal space: A case report.

Epithelioid sarcoma (ES) was first described by Enzinger in 1970. It is a rare variant of soft tissue sarcoma with a 5-year overall survival (OS) rate of 50%. Here, we reported a case of epithelioid sarcoma in the parapharyngeal space of an adult, resulting in a favorable prognosis after chemotherapy and radiation therapy. A 34-year-old female who complained of pharynx pain and discomfort was suspected of having a tumor in the right parapharyngeal space by CT scan. Excision biopsy suggested epithelioid sarcoma. Clinical and radiological studies did not reveal tumor distant metastasis in the patient. After excisional biopsy, the patient underwent chemotherapy and external beam radiation treatment. She has remained alive for 2 years and 7 months without recurrence since her last treatment. In this paper, we also provide a detailed review of the role of radiotherapy in the treatment of epithelioid sarcoma in previously reported cases.

Depletion of Survivin suppresses docetaxel-induced apoptosis in HeLa cells by facilitating mitotic slippage.

The anticancer effects of taxanes are attributed to the induction of mitotic arrest through activation of the spindle assembly checkpoint. Cell death following extended mitotic arrest is mediated by the intrinsic apoptosis pathway. Accordingly, factors that influence the robustness of mitotic arrest or disrupt the apoptotic machinery confer drug resistance. Survivin is an inhibitor of apoptosis protein. Its overexpression is associated with chemoresistance, and its targeting leads to drug sensitization. However, Survivin also acts specifically in the spindle assembly checkpoint response to taxanes. Hence, the failure of Survivin-depleted cells to arrest in mitosis may lead to taxane resistance. Here we show that Survivin depletion protects HeLa cells against docetaxel-induced apoptosis by facilitating mitotic slippage. However, Survivin depletion does not promote clonogenic survival of tumor cells but increases the level of cellular senescence induced by docetaxel. Moreover, lentiviral overexpression of Survivin does not provide protection against docetaxel or cisplatin treatment, in contrast to the anti-apoptotic Bcl-xL or Bcl-2. Our findings suggest that targeting Survivin may influence the cell response to docetaxel by driving the cells through aberrant mitotic progression, rather than directly sensitizing cells to apoptosis.

[Mobilization of Bone Marrow Mesenchymal Stem Cells Inhibits TGF-ß Non-classical Pathway Against Myocardial Fibrosis in Rats].

OBJECTIVE: To observe the relationship between the mechanism of bone marrow stem cell mobilization mediated the myocardial fibrosis inhibition in rats and the non-classical pathway mediated by transforming growth factor-ß (TGF-ß). METHODS: Twenty two Wistar rats were subcutaneously injected with isoproterenol (Iso) to establish the model of myocardial fibrosis, and then were randomly divided into control group and granulocyte colony-stimulating factor (G-CSF)-treat group (GT group). The rats in GT group were subcutaneously injected with recombinant human granulocyte stimulating factor for 5 days, and the control group was injected with normal saline. After 4 weeks, the myocardial structure was observed by pathological staining, the content of serum B type natriuretic peptide (BNP) was detected by ELISA , the expression of type Ⅲ collagen was detected by immunohistochemistry staining and the protein expression level of typeⅠcollagen, TGF-ß, transforming growth factor kinase 1 (TAK1), mitogen-activated protein kinase kinase (MKK) and p38 mitogen-activated protein kinase (p38MAPK) was determined by Western blot. RESULTS: Compared with the control group, the serum BNP level, Masson staining collagen deposition, collagen area ratio and the expression of typeⅠcollagen, TGF- ß, TAK1, MKK3 and p38MAPK in the GT group were lower than those in the control group. CONCLUSION: Bone marrow stem cell mobilization can alleviate the degree of myocardial fibrosis in rats, which is related to the inhibition of TGF- ß/TAK1/MKK/p38MAPK pathway.

The efficacy and safety of PD-1/PD-L1 inhibitors in patients with recurrent or metastatic nasopharyngeal carcinoma: A systematic review and meta-analysis.

OBJECTIVES: There is currently no effective salvage therapeutic modality that improves the survival outcomes of patients with recurrent or metastatic nasopharyngeal carcinoma. However, the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) inhibitors may provide clinical benefit for these advanced patients. MATERIALS AND METHODS: The databases, including PubMed, Web of Science, EMBASE and Cochrane Library, were systematically searched up to Nov 5, 2019. Data of objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) rate, overall survival (OS) rate, and drug-related adverse events were extracted and pooled meta-analyzed. RESULTS: From 71 search records, eight studies were included in the systematic review, of which three were eligible for final meta-analysis. In recurrent or metastatic nasopharyngeal carcinoma patients treated with anti-PD-1 therapy, the pooled ORR was 27% (95% confidence interval [CI] 19-36%), DCR was 63% (95% CI 50-75%), 6 months PFS rate was 49% (95% CI 40-58%), 1-year PFS rate was 25% (95% CI 19-32%), 1-year OS rate was 61% (95% CI 49-72%). The pooled incidences of any grade and grade ≥ 3 drug-related adverse events were 94% and 20% respectively. CONCLUSION: We present the aggregate response rates, survival rates and incidences of drug-related adverse events for recurrent or metastatic nasopharyngeal carcinoma patients receiving PD-1/PD-L1 blockage treatment, which could provide useful information for future design of clinical studies. There is a need for more randomized controlled studies with head-to-head comparison of PD-1/PD-L1 inhibitors and traditional chemotherapeutic strategies to enable better recommendations for optimal advanced nasopharyngeal carcinoma treatment.

Antiplatelet Effect of Different Loading Doses of Ticagrelor in Patients With Non-ST-Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: The APELOT Trial.

BACKGROUND: We hypothesized that a high ticagrelor loading dose (LD) may improve platelet inhibition in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI). METHODS: This interventional multicentre open-label trial randomized 278 patients with NSTE-ACS to a high (360 mg) or conventional (180 mg) ticagrelor LD. The primary outcome was the platelet reactivity index (PRI) 1 hour after administration of the LD. Secondary outcomes included PRI at 0.5 hour, 1 hour, 8 hours, and 24 hours; periprocedural myocardial infarction (PMI); major cardiac adverse events; and bleeding events. RESULTS: Two hundred sixty-two patients completed the major end points. PRI was lower in the high-LD group than in the conventional-LD group at any time point (all, P < 0.05), including at 1 hour (12.2% vs 16.7%; P = 0.023). At 0.5 hour, the high-LD group showed a lower high-platelet reactivity rate (49.6% vs 60.2%; P = 0.013) and a higher low-platelet reactivity rate (24.8% vs 12.8%; P = 0.017) than did the conventional LD group. No significant differences in the bleeding rates were found between the 2 groups (14% vs 14.3%). Four cases of PMI and 1 death in each group, as well as 1 acute myocardial infarction in the conventional LD group, occurred. There was no stroke, target lesion revascularization, or target vessel revascularization. CONCLUSIONS: Doubling the ticagrelor LD achieved faster onset and greater platelet inhibition without an increase in adverse events in patients with NSTE-ACS undergoing PCI.

Long-term nicotine exposure induces dysfunction of mouse endothelial progenitor cells.

Endothelial progenitor cells (EPCs) have an important role in maintaining endothelial homeostasis. Previous studies reported that smoking has detrimental effects on EPCs; however, recent studies revealed that short-term nicotine exposure may benefit EPCs. As most smokers are exposed to nicotine over an extended time period, the present study aimed to investigate the long-term effects of nicotine on EPCs. Mice were administered nicotine orally for 1, 3 or 6 months. The mice exposed to nicotine for 1 month demonstrated increased EPC counts and telomerase activity and reduced cell senescence compared with control mice, consistent with previous reports. However, long-term nicotine exposure resulted in opposing effects on EPCs, causing decreased counts, functional impairment and reduced telomerase activity. Furthermore, the effects of nicotine exposure were correlated with changes in sirtuins type 1 (SIRT1) protein expression. The current study indicated that long-term nicotine exposure induces dysfunction and senescence of EPCs, which may be associated with impairment of telomerase activity through SIRT1 downregulation. The present results emphasize the necessity of smoking cessation to prevent dysfunction of EPCs.

EGFR tyrosine kinase inhibitors promote pro-caspase-8 dimerization that sensitizes cancer cells to DNA-damaging therapy.

The combination of time and order-dependent chemotherapeutic strategies has demonstrated enhanced efficacy in killing cancer cells while minimizing adverse effects. However, the precise mechanism remains elusive. Our results showed that pre-treatment of MCF-7 and MDA-MB-468 cells with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib or lapatinib significantly enhanced the cytotoxic effects of DNA-damaging agents compared to coadministration of the EGFR inhibitor and DNA-damaging agent. Sequential application of erlotinib and doxorubicin increased activated caspase-8 by promoting pro-caspase-8 homodimerization and autocatalytical cleavage, whereas coadministration did not. We found that EGFR inhibitors promoted pro-caspase-8 homodimerization by inhibiting ERK pathway signaling, while doxorubicin promoted it. Our data highlight that ERK has the potential to inhibit the formation of pro-caspase-8 homodimers by phosphorylating pro-caspase-8 at S387. In conclusion, the pretreatment of EGFR tyrosine kinase inhibitors promote pro-caspase-8 dimerization that sensitizes cancer cells to DNA-damaging agents. Our findings provide rationale for novel strategies for the implementation of combined targeted and cytotoxic chemotherapy within a new framework of time and order-dependent therapy.

Acetylation of Beclin 1 inhibits autophagosome maturation and promotes tumour growth.

Beclin 1, a protein essential for autophagy, regulates autophagy by interacting with Vps34 and other cofactors to form the Beclin 1 complex. Modifications of Beclin 1 may lead to the induction, inhibition or fine-tuning of the autophagic response under a variety of conditions. Here we show that Beclin 1 is acetylated by p300 and deacetylated by SIRT1 at lysine residues 430 and 437. In addition, the phosphorylation of Beclin 1 at S409 by CK1 is required for the subsequent p300 binding and Beclin 1 acetylation. Beclin 1 acetylation inhibits autophagosome maturation and endocytic trafficking by promoting the recruitment of Rubicon. In tumour xenografts, the expression of 2KR mutant Beclin 1 (substitution of K430 and K437 to arginines) leads to enhanced autophagosome maturation and tumour growth suppression. Therefore, our study identifies an acetylation-dependent regulatory mechanism governing Beclin 1 function in autophagosome maturation and tumour growth.

Inhibition of DNA methyltransferase as a novel therapeutic strategy to overcome acquired resistance to dual PI3K/mTOR inhibitors.

Dual PI3K/mTOR(phosphatidylinositol 3-kinase/mammalian target of rapamycin) inhibitors are being evaluated clinically for the treatment of tumors with a hyperactivated PI3K/mTOR pathway. However, unexpected outcomes were obtained in clinical studies of cancer patients with an aberrant PI3K pathway. In clinical trials, applicable combination regimens are not yet available. In this study, using an integrated analysis of acquired BEZ235-resistant nasopharyngeal carcinoma cells, we demonstrate that DNA methyltransferase is a key modulator and a common node upstream of the AKT/mTOR and PDK1/MYC pathways, which are activated in cancer cells with acquired BEZ235 resistance. DNA methyltransferases were upregulated and induced PTEN and PPP2R2B gene hypermethylation, which downregulated their expression in BEZ235-resistant cancer cells. Reduced PTEN and PPP2R2B expression correlated with activated AKT/mTOR and PDK1/MYC pathways and conferred considerable BEZ235 resistance in nasopharyngeal carcinoma. Targeting methyltransferases in combination with BEZ235 sensitized BEZ235-resistant cells to BEZ235 in vitro and in vivo, suggesting the potential clinical application of this strategy to overcome BEZ235 resistance.

Oxidized low-density lipoprotein-induced CD147 expression and its inhibition by high-density lipoprotein on platelets in vitro.

INTRODUCTION: Matrix metalloproteinases (MMPs) are believed to progressively degrade the collagenous components of the protective fibrous cap, leading to atherosclerotic plaque rupture or destabilization. Oxidized low-density lipoprotein (ox-LDL) enhances the release of CD147, known as the extracellular MMP inducer, from coronary smooth muscle cells. However, whether ox-LDL can induce platelet CD147 expression is unknown. Therefore, we investigated the influence of ox-LDL and high-density lipoprotein (HDL) on CD147 expression on human platelets. MATERIALS AND METHODS: Washed platelets were incubated with ox-LDL (or native LDL) and HDL or anti-LOX-1 monoclonal antibody prior to incubation with ox-LDL. In parallel, buffer (PBS) was added to washed platelets as a control. The expression levels of CD147, CD62P, CD63 and Annexin V were assessed by flow cytometry, and soluble CD147 from the platelets was assessed by an enzyme-linked immunosorbent assay. Laser scanning microscopy (LSM) and transmission electron microscopy (TEM) were used to visualize the morphological changes and granule release, respectively, from the platelets. RESULTS: Platelets treated with ox-LDL exhibited a significant increase in the expression of CD147 (or Annexin V), followed by increases in CD62P and CD63, compared with the control group. In contrast, HDL or anti-LOX-1 monoclonal antibody decreased these effects. The expression of soluble CD147 increased as the concentration of ox-LDL used to treat the platelets increased. After exposure to ox-LDL, morphological changes and granule release in the platelets were visualized by LSM and TEM. Additionally, the TEM revealed that HDL inhibits alpha-granule release. CONCLUSIONS: In platelets, ox-LDL stimulates the release of CD147 via binding to LOX-1, whereas HDL inhibits this effect. This finding could provide new insights concerning the influence of ox-LDL and HDL on plaque stability by the up-regulation of CD147 on platelets.

Allogeneic bone marrow mesenchymal stem cells transplantation for stabilizing and repairing of atherosclerotic ruptured plaque.

INTRODUCTION: There have been no satisfactory therapies on stabilizing and repairing ruptured plagues nowadays, which are the fundamental causes of acute coronary syndrome (ACS) and stroke. The aim of this study was to investigate the therapeutic potential of bone marrow mesenchymal stem cells (MSCs) in stabilizing and repairing ruptured plaques. MATERIALS AND METHODS: 28 male New Zealand rabbits were randomly divided into 2 groups after establishment of atherosclerotic disrupted plaque model by liquid nitrogen frostbite: MSCs transplantation group and control group. MSCs were isolated, cultured in vitro, and labeled with BrdU. BrdU-incorporated MSCs (MSCs transplantation group) or an equal amount of IMDM medium without MSCs (control group) were transplanted into vessels with ruptured plaque. PAI-1, MMP-9 and hs-CRP were determined by ELISA of blood 3 days and 4 weeks after transplantation. Rabbits were sacrificed 4 weeks after transplantation and plaque repair was assessed by HE and Masson's trichrome staining. Transplanted BrdU-positive cells were identified by immunohistochemistry. RESULTS: Four weeks after MSCs transplantation, PAI-1, MMP-9 and hs-CRP were reduced significantly in all experimental animals (p < 0.001). The reduction was more evident in the transplantation group than in the control group (p < 0.01). In addition, the transplantation group showed dramatically higher numbers of newly formed endothelial cells, collagen fibers, and proliferative BrdU-positive cells at plaque areas. CONCLUSION: This study demonstrates that allogeneic MSCs transplantation can stabilize and repair ruptured plaques, which represents a novel approach for ACS and stroke.

[Novel MYBPC3 mutations in Chinese patients with hypertrophic cardiomyopathy].

OBJECTIVE: To screen the MYBPC3 gene mutations in Han Chinese patients with hypertrophic cardiomyopathy (HCM). METHODS: Sixty-six patients with HCM were enrolled for the study. The exons in the functional regions of MYBPC3 were amplified with PCR and the products were sequenced. RESULTS: Four novel mutations and four common polymorphisms were identified in this patient cohort. A Lys301fs mutation in exon10 was evidenced in a H30, and when he was 47 years old, he had the chest tightness, shortness of breath with septal hypertrophy of 18.7mm; a Asp463stop mutation in exon17 was detected in a H48, he was 24 years old 24-year-old when a medical examination showed ventricular septal hypertrophy of 15.4 mm; both Gly523Arg mutation in exon18 and Tyr847His mutation in exon26 were found in a H53 with onset age 36 years old, feeling chest tightness after excise and his ventricular septal hypertrophy was 27 mm that time. MYBPC3 mutations occurred in 4.5% patients in this cohort. These mutations were not found in 100 non-HCM control patients. CONCLUSION: MYBPC3 mutation is presented in a small portion of Han Chinese patients with HCM.

[Novel mutations of potassium channel KCNQ1 S145L and KCNH2 Y475C genes in Chinese pedigrees of long QT syndrome].

OBJECTIVE: Hereditary long QT syndrome (LQTS) is a cardiac disorder characterized by prolongation of QT interval on electrocardiograms (ECGs) and syncope and sudden death caused by a specific multi-polymorphic ventricular tachyarrhythmia known as torsade de pointes. LQTS is caused by mutations in cardiac sodium channel gene SCN5A; potassium channel subunit genes KCNQ1, KCNH2, KCNE1, KCNE2, KCNJ2; calcium channel gene Cav2.1. and ankyrin-B gene ANK2. METHODS: We characterized 77 Chinese LQTS patients with clinical manifestations and mutations in the main LQTS genes, KCNQ1 and KCNH2 using PCR and sequence analysis. RESULTS: The spectrum of ST-T-wave patterns of 24 (31.2%) probands were considered as LQT1, 42 (54.5%) as LQT2 and 3 (3.9%) as LQT3. The remaining 8 (10.3%) could not be characterized. The average age for this population of LQTS patients was (27.6 +/- 16.4) years and the average QTc (561 +/- 70) ms, and the age of the first syncopal attack was (17.6 +/- 14.7) years. The triggering factors for cardiac events happening in these mutation carriers included physical exercise, emotional excitement and auditory irritation. We identified 4 KCNQ1 mutations and 7 KCNH2 mutations. Six of them were first identified with some data already shown. In this paper we showed the data of 6 other mutations. CONCLUSIONS: LQT2 is the most common type of LQTS in Chinese; 2 mutations of KCNQ1 and KCNH2 were first identified in this report; there are some differences between Chinese and North American or European LQTS patients in clinical characters and ECG.

[Analysis of MYH7, MYBPC3 and TNNT2 gene mutations in 10 Chinese pedigrees with familial hypertrophic cardiomyopathy and the correlation between genotype and phenotype].

OBJECTIVE: The aim of this study was to screen the disease-causing gene mutations and investigate the genotype-phenotype correlation in 10 Chinese pedigrees with familial hypertrophic cardiomyopathy (HCM). METHODS: There are 91 family members from these 10 pedigrees and 5 members were normal mutated carriers, 23 members were HCM patients (14 male) aged from 1.5 to 73 years old. The functional regions of myosin heavy chain gene (MYH7), cardiac myosin-binding protein C (MYBPC3) and cardiac troponin T gene (TNNT2) were screened with PCR and direct sequencing technique. Clinical information from all patients was also evaluated in regard to the genotype. RESULTS: Mutations were found in 5 out of 10 pedigrees. Mutations in MYH7 (Arg663His, Glu924Lys and Ile736Thr) were found in 3 pedigrees and 3 patients from these pedigrees suffered sudden death at age 20-48 years old during sport. Mutations in MYBPC3 were found in 2 pedigrees, 1 with complex mutation (Arg502Trp and splicing mutation IVS27 + 12C > T) and 1 with novel frame shift mutation (Gly347fs) and the latter pedigree has sudden death history. No mutation was identified in TNNT2. CONCLUSIONS: Although the Han Chinese is a relatively homogeneous ethnic group, different HCM gene mutations were responsible for familiar HCM suggesting the heterogeneity nature of the disease-causing genes and HCM MYH7 mutations are associated with a higher risk of sudden death in this cohort. Furthermore, identical mutation might result in different phenotypes suggesting that multiple factors might be involved in the pathogenesis of familiar HCM.

[Heterozygous mutation in KCNQ1 cause Jervell and Lange-Nielsen syndrome].

OBJECTIVE: Jervell and Lange-Nielsen syndrome (JLNS) is a severe cardioauditory syndrome manifested as QT interval prolongation, abnormal T waves, and relative bradycardia ventricular tachyarrhythmias. In this report, we screened a nonconsanguineous families with JLNS for mutations in KCNQ1. METHODS: Mutation analysis was performed by using purified PCR products to direct sequence analysis on an ABI-3730XL automated DNA sequencer. The whole sequence of proband' KCNQ1 was screened firstly, then screened the mutation exon sequences of others of the family and 50 unrelated normal persons. RESULTS: A heterogeneous mutation was identified in the patients of the JLNS family, a missense mutation (G-->T) at nucleotide 917 encoded in exon 6 of KCNQ1. This substitution leads to a change from glycine to Valine at codon 306(G306V) corresponding to the S5 transmembrane segment of KCNQ1. The other normal members of the family and 50 unrelated normal persons were not identified this mutation. CONCLUSION: The result suggested that not only homozygous mutations or compound heterozygous mutations in KCNQ1 could cause Jervell-Lange-Nielsen syndrome, the single heterozygous mutation may also cause Jervell-Lange-Nielsen syndrome.

[The mutation scanning of KCNQ1 gene for 31 long QT syndrome families].

OBJECTIVE: To search for the mutations of potassium voltage-gated channel, KQT-like subfamily member 1(KCNQ1) gene in 31 Chinese long QT syndrome(LQTS) families. METHODS: Due to the genetic heterogeneity, the genotype of patients was first predicted based on the spectrum of ST-T-wave patterns on ECG. Ten of 31 probands were considered as LQT1. Then the mutation of KCNQ1 gene was screened by the polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) technique combined with DNA sequencing in all members of these 10 families. To avoid omitting some LQT1 patients without typical characteristics and also to do methodological comparison, the mutations of KCNQ1 gene on 16 exons were screened by PCR and direct DNA sequencing in the rest 21 non-LQT1 probands only. Co-segregation analysis was carried out after the finding of an abnormal sequence. In case that the abnormality existed in patients only, the test of such exon was performed in 50 irrelevant normal individuals. RESULTS: Two missense mutations and three single nucleotide polymorphisms (SNPs) were found in the LQT1 predicted families. The two mutations were S277L (1 family) and G306V (1 family) in exon 5 and were not reported previously. Three polymorphisms were 435C-->T (7 families), 1632C-->A (1 family), and IVS1+9 C-->G (3 families). Only a splice mutation IVS1+5G-->A (2 families) and a polymorphism IVS10+18C-->T (1 family) were found in the non-LQT1 predicted probands. All three mutations were localized within the functional domain of KCNQ1 and were co-segregated with the disease, and were not found in 50 normal individuals. CONCLUSION: Two novel missense mutations, 1 splice mutation and four SNPs on KCNQ1 gene were found in the 31 LQTS families. Combined with ECG-based genotype prediction, PCR-SSCP could find most mutations on KCNQ1 and be a simple and economic method for screening LQTS.