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@#Septin is a highly conserved class of GTP-binding proteins found in eukaryotes other than higher plants.The different subtypes of Septin can form higher order structures such as filamentous or ring-like structures in the form of heterodimer to perform their functions,which can regulate physiological processes such as yeast budding and cell division,as well as participating in the defense response of the host cell.Abnormal expression or mutation of Septin is closely related to the occurrence and development of tumors and neurological diseases.This paper summarized the physiological functions of the Septin family,the effects of Septin on the occurrence and development of tumors and neurological diseases,and the role of Septin in the host immune response.
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Objective:To investigate the mechanism of Candida albicans Int1 in regulating septin organization. Methods:A series of full-length and truncated fragments of Int1 were constructed and fused with green fluorescent protein (GFP). The intracellular localization of the fusion proteins was observed under a fluorescence microscope. The region in Int1 that was required for bud neck localization was identified. Full-length and fragments of Int1 were overexpressed in the yeast Saccharomyces cerevisiae and the changes in cell growth, cell morphology and septin organization were investigated to determine the functional region in Int1 that mediated the interaction with septin. Moreover, the co-localization of the region and septin was analyzed. Results:The full-length Int1 consisted of 1 661 amino acid residues. A middle region of 209 amino acid residues, Int1-M4 (739-947 aa), that could be localized at the bud neck during both small and large bud periods was identified. Overexpression of Int1-M4 led to significant growth defects, elongated bud and disorganized septin. In the cells with elongated bud, Int1-M4 and septin with abnormal structures could be co-localized.Conclusions:Int1-M4 (739-947 aa), the middle region of Int1 containing 209 amino acid residues, mediated the bud neck localization and the interaction with septin, playing an important role in regulating septin organization.
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OBJECTIVES@#To explore the correlation between cytosine-phosphoric-guanylic (CpG) site of Septin 9 gene and colorectal cancer, and to develop a real-time PCR detection system in plasma in patients with colorectal cancer.@*METHODS@#The methylation of training samples was detected by high-throughput sequencing technology, and the sites highly consistent with the clinical information of colorectal cancer were identified. Then the detection system of real-time PCR was designed to analyze the consistency of plasma and tissue based on methylationa sensitive enzyme digestion. Finally, 100 clinical trials were conducted to evaluate the performance of the detection system with the methylation sensitive enzyme digestion-real-time PCR.@*RESULTS@#The highly consistent sites, which were selected by high-throughput sequencing from 71 training set samples, was the 38th CpG. Based on the detection region, the screened methylation sensitive enzymes were @*CONCLUSIONS@#The 38th CpG site of Septin 9 detected by the detection system of methylation sensitive enzyme digestion-real-time PCR can highly predict the occurrence of colorectal cancer with great clinical application value.
Subject(s)
Humans , Colorectal Neoplasms/genetics , CpG Islands/genetics , DNA , DNA Methylation , Plasma/metabolism , Septins/metabolismABSTRACT
Objective@#To develop a kind of quality control material which simulates clinical specimens for detecting plasma methylated Septin9 (mSEPT9) and investigate the performance for mSEPT9 detection in external quality assessment (EQA) of laboratories. @*Methods@#The cultured Hela and Jurkat cells, known to contain methylated and unmethylated Septin9 gene respectively, were cultured. The genomic DNA of the cells was collected and extracted, and detected by mSEPT9 kit. According to the Ct value, the genomic DNA was diluted into different concentrations of quality control materials with negative plasma. The homogeneity and stability of the quality control materials were evaluated. The panels consisted of 5 blindly coded samples were distributed to EQA participants and the results were summarized and evaluated. @*Results@#The purity and concentration of extracted genomic DNA met with the needs of use and could be used as quality control products for mSEPT9 detection. The homogeneity and stability met with the requirements of China National Accreditation Service for Conformity Assessment. Some of the participating laboratories occurred false positive results and false negative results, and a good linear correlation for the detected results (Ct values) was only observed in about 55.6% of the laboratories. Among the 9 participating laboratories, 7 laboratories (77.8%) performed well, 1 laboratory (11.1%) qualified, and 1 laboratory (11.1%) unqualified. @*Conclusion@#The quality control materials for mSEPT9 detection was successfully developed and the application in external quality assessment should be of great significance for evaluating and improving the detection ability of clinical laboratory.
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Objective@#To evaluate the value of methylation detection of plasma Septin9 gene in the diagnosis of colorectal cancer (CRC) and verify its performance. @*Methods@#The plasma samples from 32 CRC patients before colonoscopy and 10 healthy controls during October 2016 and May 2017 were collected, and the methylation levels of Septin9 gene in these samples were detected by the detection kit of plasma Septin9 gene methylation. The coincidence rate, detection limit and precision of the kit in the diagnosis of CRC were evaluated, and its diagnostic value was compared with that of carcinoembryonic antigen (CEA) and facal immunochemical tests (FIT). @*Results@#The positive and negative coincidence rates of the plasma Septin9 gene methylation kit in the detection of CRC were 100%. The reference materials assigned the detection limit were positive, and the coefficient of variation (CV) of precision was less than 5%, which met the basic performance requirements. The sensitivity, specificity, positive predictive value and negative predictive value of the kit in the diagnosis of CRC were 62.50%, 90.00%, 95.20% and 42.90%, respectively. The detection rate of CRC by the kit was 62.50%, significantly higher than those of FIT (28.13%) and CEA (28.13%) (all P＜0.05). The area under the ROC curve (AUC ROC ) of the kit in the diagnosis of CRC was 0.762, and the detection rate of stage Ⅰ CRC by the kit was 50.00%. @*Conclusion@#The performance of the plasma Septin9 gene methylation kit meets the anticipated clinical requirements, which may be used as a serological marker for the assistant diagnosis of CRC.
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Septin 9 (SEPT9) gene, a member of the conserved framework protein genes family, has guanosine triphosphataseg (GTPase) activity and play an important role in a wide range of biological processes such as cell division, cell polarization and membrane remodeling.Accumulated evidence have confirmed that SEPT9is closely related to the generation and development of human diseases.And SEPT9has become the new aroused general interest in tumor related research at this stage.This article mainly reviews the structural features of SEPT9gene, action mechanism of SEPT9protein and the role of SEPT9gene in a variety of common oncogenesis, and explores the potential value of SEPT9as a marker in early tumor screening.
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Objective To establish the blood Septin9 methylation detection system for early screening of colorectal cancer based on fluorescence PCR technology .Methods The PCR primer of Septin9 was designed by searching the CpG island site of Septin9 methylation in the NCBI database .The high methylation site of Septin9 gene promoter region was confirmed by PCR amplification and sequencing after extracting DNA from colorectal cancer and para-carcinoma tissues .The fluorescence PCR and TaqMan probe detection technique was designed by aiming at high methylation site for constructing the plasma sample methylation detection sys-tem .Then its accuracy ,specificity ,repeatability and minimum detectable amount were performed the assess-ment and analysis .The SETP9 methylation detection was performed in plasma samples from 57 cases of color-ectal cancer and 30 healthy persons .Results The high methylation site of Septin9 gene in tissue samples was confirmed by sequencing .This site served as the target for designing fluorescence PCR detection system .After assessment ,the accuracy ,specificity and repeatability of this detection system were 100％ ,the lowest detection amount reached 0 .1 ng/μL .Among the plasma samples in 57 cases of colorectal cancer ,the positive rate of Septin9 methylation site detection was 71 .92％ (41/57) and the positive rate of in the patients with pathologi-cal stage Ⅰ and Ⅱ of colorectal cancer reached 64 .2％ .But Septin9 gene had no methylation in plasma of healthy population .Conclusion The plasma fluorescence PCR detection system with Septin9 gene methylation as the target has the characteristics of high sensitivity ,high specificity and high accuracy ,which is the reliable detection technique for the early screening of colorectal cancer and has good clinical application prospect .
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Objective:A meta-analysis was use to systematically assess the diagnostic value of Septin-9 in Colorectal cancer. Methods:Literature fulfilling the criteria was searched in PubMed, Foreign Medical Journals Platform, Ovid, CNKI, CBM, WanFang and VIP Databases from inception to Jan. 2017. Literatures were strictly screened according to the inclusion and exclusion cri-teria. Study quality was assessed in terms of the Quality Assessment of Diagnostic Accuracy Studies ( QUADAS) checklist. A bivariate Meta-analysis model was employed to assess the pooled accuracy,and study heterogeneity was evaluated via Cochran-Q and I2 tests;subgroup analysis and sensitivity analysis were conducted to deeply trace the sources of heterogeneity;publication bias was judged by Deek′s funnel plot. Results:A total of 11 studies were included. Analysis of methylated Septin-9 achieved a pooled sensitivity of 0. 70 (95%CI:0. 67-0. 72),specificity of 0. 91 (95%CI:0. 90-0. 92),and DOR of 28. 76(95%CI:17. 70-46. 75),corresponding to an AUC of 0. 9221. Heterogeneity test suggested that there was obvious heterogeneity from non-threshold effect. Sensitivity analysis identified one outlier study. Subgroup analysis results showed that the AUC of 1/3 positive to 2/3 positive group was 0. 9397 versus 0. 8265,and the AUC of the Asian population group to the Caucasian population group was 0. 9368 versus 0. 9210. Funnel plot ( Deek′s) revealed no publication bias. Conclusion:Our data indicate that circulating methylated Septin-9 seemed to harbor a relatively high accuracy in conforming colorectal cancer,and might be popularized as a routine biomarker for colorectal cancer detection.
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Objective:A meta-analysis was use to systematically assess the diagnostic value of Septin-9 in Colorectal cancer. Methods:Literature fulfilling the criteria was searched in PubMed, Foreign Medical Journals Platform, Ovid, CNKI, CBM, WanFang and VIP Databases from inception to Jan. 2017. Literatures were strictly screened according to the inclusion and exclusion cri-teria. Study quality was assessed in terms of the Quality Assessment of Diagnostic Accuracy Studies ( QUADAS) checklist. A bivariate Meta-analysis model was employed to assess the pooled accuracy,and study heterogeneity was evaluated via Cochran-Q and I2 tests;subgroup analysis and sensitivity analysis were conducted to deeply trace the sources of heterogeneity;publication bias was judged by Deek′s funnel plot. Results:A total of 11 studies were included. Analysis of methylated Septin-9 achieved a pooled sensitivity of 0. 70 (95%CI:0. 67-0. 72),specificity of 0. 91 (95%CI:0. 90-0. 92),and DOR of 28. 76(95%CI:17. 70-46. 75),corresponding to an AUC of 0. 9221. Heterogeneity test suggested that there was obvious heterogeneity from non-threshold effect. Sensitivity analysis identified one outlier study. Subgroup analysis results showed that the AUC of 1/3 positive to 2/3 positive group was 0. 9397 versus 0. 8265,and the AUC of the Asian population group to the Caucasian population group was 0. 9368 versus 0. 9210. Funnel plot ( Deek′s) revealed no publication bias. Conclusion:Our data indicate that circulating methylated Septin-9 seemed to harbor a relatively high accuracy in conforming colorectal cancer,and might be popularized as a routine biomarker for colorectal cancer detection.
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objective To identify SEPT7as one of the target genes of miR-19a and miR-19b.MethodsmiR-19a inhibitor and miR-19b inhibitor mediated by lipofectamine2000,were transfected to SNB19 glioma cells for knocking down miR-19a/19b overexpression.Real time PCR was conducted to detect the expression of miR-19a/miR-19b in transfected cells.The expression of SEPT7was determined by Western blot analysis.RT-PCR was used to detect the mRNA expression of SEPT7; and Luciferase reporter assay was used to identify the direct regulation of miR-19a/19b on SEPT7.ResultsIn SNB19 glioma cells transfected with miR-19a/19b inhibitor,the expression of miR-19a/miR-19b was significantly reduced,whereas the protein expression of SEPT7 was upreguhtted; no significant change of SEPT7 mRNA level was found and luciferase activity became stronger as compared to control cells.ConclusionSEPT7 is the target negatively regulated by miR-19a and miR-19b.