2.Genetic improvement of alpha-amylase producing Bacillus licheniformis by homolog-mediated alpha-amylase gene amplification.
Dandan NIU ; Guiyang SHI ; Zhengxiang WANG
Chinese Journal of Biotechnology 2009;25(3):375-380
Bacillus licheniformis alpha-amylase (BLA) is one of the most important enzymes involved in starch hydrolysis and many biotechnological processes. To improve the BLA productivity, an integrative plasmid pBL-amyL carrying amyL gene encoding a thermophilic alpha-amylase of B. licheniformis was constructed and transformed into B. licheniformis B0204, an industrial alpha-amylase producer. The transformants harboring different copies of amyL were developed on kanamycin by using homolog-mediated chromosomal amplification of alpha-amylase gene. The recombinants with different multiple copies of amyL integrated in the chromosome were identified by real-time PCR and evaluated by shake-flask fermentation. Recombinants harboring 2-5 multiple copies of amyL produced more alpha-amylase comparison to the parental strain B0204.
Bacillus
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enzymology
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genetics
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Gene Amplification
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Industrial Microbiology
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Nucleic Acid Amplification Techniques
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Transformation, Genetic
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alpha-Amylases
;
biosynthesis
;
genetics
3.An improved association analysis pipeline for tumor susceptibility variant in haplotype amplification area.
Yu GENG ; Rongrong YANG ; Jing ZHANG
Journal of Southern Medical University 2020;40(10):1493-1499
OBJECTIVE:
Haplotype amplification on germline variants is suggested to imply potential selective advantages and clonal expansion susceptibility and has become an important signature for seeking cancer susceptibility gene.Here we propose an improved association method that fully considers the haplotype amplification status.
METHODS:
The haplotype amplification status was estimated by the variant allelic frequencies.We adopted a permutation test on variant allelic frequencies to divide the candidate variants into multiple groups.A likelihood clustering method was then applied to establish the neighborhood system of the hidden Markov random field framework.A filtering pipeline was introduced into the proposed method to further refine the candidate variants, including a Wilson's interval filter and a false discovery rate controller.The final candidate set along with the haplotype amplification status was collapsed into the weighted virtual sites for association tests.
RESULTS:
Through simulated tests on a series of datasets, we compared the type Ⅰ error rates of different minor allele frequencies, which stably fell within 2%, suggesting good robustness of the algorithm.In addition, we compared another 5 published association approaches for Type-Ⅰ and Type-Ⅱ error rates with the proposed method, which resulted in the error rates all within 2%, demonstrating significant advantages and a good statistical ability of the proposed method.
CONCLUSIONS
The proposed method can accurately identify tumor susceptibility variants in haplotype amplification area with good robustness and stability.
Algorithms
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Cluster Analysis
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Gene Amplification
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Gene Frequency
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Haplotypes
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Humans
;
Neoplasms/genetics*
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Polymorphism, Single Nucleotide
4.Analysis on genetic diversity and genetic relationship of medicinal species in Dipsacus from China by SRAP.
Da-xia CHEN ; Xue ZHANG ; Yu WANG ; Long-yun LI ; Ze ZHANG
China Journal of Chinese Materia Medica 2015;40(13):2559-2564
The author detected the genetic diversity and genetic relationship within and among eight medicinal species of Dipsacus by the approach of sequence-related amplified polymorphism (SRAP). The associated genetic parameters were calculated by POPGENE 1.31. The Genetic distance was calculated by TREECONW and the systematic diagrams of genetic relationship were clustered by UPG-MA. The results showed that, using 26 primers, a total of 558 bands were produced, of which 539 were polymorphic loci. There was a high level of genetic diversity among species (PPB = 96.59%, Na = 1.9659, Na = 1.3375, H = 0.2143, I = 0.3423). However, genetic diversity was lower within species, the average of genetic parameters was PPB = 6.97%, Na = 1.0697, Na = 1.0311, H = 0.0187, I = 0.0291. The Nei's genetic differentiation coefficient was 0.9126, indicated that most of the genetic variation existed among species. By clustering analysis, different individuals gathered in the same group and the classified result of SRAP marker between traditional modal characters was almost same. The results confirmed that SRAP marker can be used as one of the effective methods to reveal the genetic diversity and relationship among medicinal species of Dipsacus.
China
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Dipsacaceae
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classification
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genetics
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Gene Amplification
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Genetic Variation
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Plants, Medicinal
;
classification
;
genetics
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Polymorphism, Genetic
5.Clinicopathologic significance of chromosome 17 polysomy in breast cancer.
Ya-li LÜ ; Mei ZHONG ; Lin LIU ; Li-xin WEI ; Po ZHAO
Chinese Journal of Pathology 2008;37(2):88-91
OBJECTIVETo investigate the clinicopathological significance of chromosome 17 polysomy in breast cancer.
METHODSRetrospective study of 200 cases of breast cancer including 106 cases of invasive ductal carcinoma and 94 cases of in-situ carcinoma was performed by fluorescence in-situ hybridization (FISH) to explore the relationship between chromosome 17 polysomy and age, nuclear atypia, lymphatic metastasis, HER2 gene amplification and HER2 protein expression.
RESULTSTwenty-six percent (52/200) of chromosome 17 polysomy was detected in 200 cases of breast ductal carcinoma, all of which were invasive ductal carcinoma. Overall 52. 8% (52/180) of invasive ductal carcinoma cases showed chromosome 17 polysomy, which was correlated to HER2 gene amplification (P = 0.000) and HER-2 protein expression (P=0.000), and to HER2 expression combined with HER2 gene amplification (P=0.001). Chromosome 17 polysomy with or without HER2 gene amplification was also associated with high-grade nuclear atypia (P = 0.012 or P = 0.010) and lymphatic metastasis (P = 0.002 or P = 0.009 ). However, chromosome 17 polysomy with or without HER2 gene amplification was not correlative with the age of patients (P = 1. 000 or P = 0. 415).
CONCLUSIONChromosome 17 polysomy may be related to the nuclear atypia, metastasis, HER2 gene amplification of invasive ductal carcinoma and thus a worse prognosis of the patients.
Breast Neoplasms ; genetics ; pathology ; Carcinoma, Ductal ; genetics ; Chromosome Aberrations ; Chromosomes, Human, Pair 17 ; genetics ; Gene Amplification ; Gene Dosage ; Gene Expression Regulation, Neoplastic ; genetics ; Genes, erbB-2 ; genetics ; Humans
7.Preparation and characterization of reference samples of Mycobacterium tuberculosis culture filtrate protein-10 for time-resolved fluoroimmunoassay.
Fang-fang GUO ; Li-lin ZOU ; Ying-song WU ; Zhi-ming HU ; Jin-long LI ; Jian-xin LV ; Ji-min GAO
Journal of Southern Medical University 2011;31(6):955-959
OBJECTIVETo prepare reference samples of Mycobacterium tuberculosis culture filtrate protein-10 (CFP-10) and CFP10-streptavidin fusion proteins (CFP10/SA) for time-resolved fluoroimmunoassay (TRFIA).
METHODSThe CFP10 gene was amplified by PCR from Mycobacterium tuberculosis strain H37Rv and cloned into pET24b, pET24b-streptavidin (SA) or pET21a-SA expression vectors. The recombinant proteins CFP10, CFP10-SA and SA-CFP10 were expressed in Rosetta cells, purified via nickel affinity chromatography and refolded by dialysis. The sensitivity and stability of the resultant proteins as reference samples were evaluated by double-antibody sandwich TRFIA.
RESULTSCFP10-SA and SA-CFP10 fusion proteins were expressed as inclusion bodies, whereas CFP10 was expressed in a soluble form. The resultant purity of the 3 recombinant proteins all exceeded 95%. TRFIA results showed that CFP-SA fusion protein possessed the best sensitivity (0.02 µg/L) and stability.
CONCLUSIONThe reference samples of CFP10 for TRFIA detection have been successfully prepared and can be used in the development of a diagnostic kit for Mycobacterium tuberculosis.
Bacterial Proteins ; genetics ; standards ; Fluoroimmunoassay ; methods ; Gene Amplification ; Mycobacterium tuberculosis ; isolation & purification ; Reference Standards
8.Amplification of c-erbB-2 proto-oncogene in cancer foci, adjacent normal, metastatic and normal tissues of human primary gastric adenocarcinomas.
Jun Suk KIM ; Chul Won CHOI ; Byung Soo KIM ; Sang Won SHIN ; Yeul Hong KIM ; Yong Jae MOK ; Jong Suk KIM ; Bum Hwan KOO
Journal of Korean Medical Science 1997;12(4):311-315
Genetic damages are frequently found in both tumor and normal cells at carcinogen exposed areas in the patients with upper aerodigestive tract cancer. These phenomena are explained by the multistage process and/or field cancerization theories. The c-erbB-2 proto-oncogene has been amplified in many human tumors including breast, stomach, kidney and lung cancers. To study the possible evidence of multistage process and/or field cancerization in the development of gastric adenocarcinoma, the amplification statuses of c-erbB-2 proto-oncogene using the Southern hybridization technique were evaluated at the 45 gastric adenocarcinoma specimen sets consisting of tumor tissue, adjacent normal tissue (within 2 cm of the primary tumor), metastatic tissue and normal stomach tissue (at least 5 cm away from primary tumor). As a result, c-erbB-2 proto-oncogene at 2 specimen sets (4.4%) was amplified 2- to 4-fold to normal control status. In these 2 cases, c-erbB-2 proto-oncogene at histologically normal tissue adjacent to tumor tissue was amplified. And, the metastatic tissue of 1 case also exhibited c-erbB-2 proto-oncogene amplification of which the degree was less than that of tumor tissue. From these results, we were able to suspect that c-erbB-2 proto-oncogene amplification in the normal tissue adjacent to tumor tissue could be a biomarker of premalignant changes in a small proportion of gastric adenocarcinoma patients. And, this result might suggest the possible role of multistage process and/or field cancerization in the development of gastric adenocarcinoma.
Adenocarcinoma/secondary
;
Adenocarcinoma/genetics*
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Blotting, Southern
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Cell Differentiation/genetics
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Gene Amplification
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Genes, erbB-2*
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Human
;
Reference Values
;
Stomach Neoplasms/genetics*
9.Diagnostic value of MDM2 RNA in situ hybridization in atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma.
Chen CHEN ; Xin HE ; Wen Yi JING ; Yan QIU ; Min CHEN ; Tian You LUO ; Xiao Yu LIU ; Hui Juan CHEN ; Hong Ying ZHANG ; Hong BU
Chinese Journal of Pathology 2022;51(3):190-195
Objective: To investigate the value of MDM2 RNA in situ hybridization (RNA-ISH) in diagnosing atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) and dedifferentiated liposarcoma (DDL). Methods: A total of 26 ALT/WDL/DDLs diagnosed from March 2017 to May 2019 in West China Hospital, Sichuan University, Chengdu, China and 18 control cases were included. MDM2 RNA-ISH was performed on all samples and compared with the fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) regarding their performance in detecting MDM2. Results: All samples were detected successfully using the three methods. Among 26 ALT/WDL/DDLs, all cases showed MDM2 amplification and positivity for MDM2 RNA-ISH (26/26, 100%). Twenty-four (24/26, 92.3%) of the 26 tested cases were positive for MDM2 IHC while two of them were negative. Eighteen control cases were all negative for MDM2 FISH and RNA-ISH, and 15 (15/18) cases were negative for MDM2 IHC. The sensitivity and specificity of RNA-ISH were both 100%, and those of MDM2 IHC were 92.3% and 83.3%, respectively. Diffuse staining was identified in all MDM2 RNA-ISH positive ALT/WDL/DDLs, but identified in only 8/24 (33.3%) of the MDM2 IHC positive cases. Among the 11 ALT/WDL/DDL samples evaluated on tissue microarray, the positive rate of MDM2 RNA-ISH was 100% with diffuse staining in all cases. The positive rate of MDM2 IHC was 9/11 while only 1 of the 9 cases showed diffuse staining. The result of MDM2 RNA-ISH was identical to that of MDM2 FISH and was overall consistent with that of MDM2 IHC (Kappa=0.763, P<0.001). Conclusions: In ALT/WDL/DDLs, results of MDM2 RNA-ISH are highly consistent with those of FISH. MDM2 RNA-ISH is more sensitive and more specific and has more diffuse positive signals than the IHC. The findings indicate that MDM2 RNA-ISH is highly valuable for the diagnosis and differential diagnosis of ALT/WDL/DDLs.
Biomarkers, Tumor/genetics*
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Gene Amplification
;
Humans
;
In Situ Hybridization, Fluorescence
;
Liposarcoma/genetics*
;
Proto-Oncogene Proteins c-mdm2/genetics*
;
RNA
10.Amplification of EMS1 gene in oral carcinogenesis.
Juan XIA ; Bing-qi LI ; Xin ZENG ; Qian-ming CHEN ; Yuan HE ; Yang CAI
Chinese Journal of Stomatology 2005;40(2):102-104
OBJECTIVETo investigate the amplification of EMS1 gene in the carcinogenesis of oral mucosa.
METHODSA total of 78 subjects, including 30 patients with oral leukoplakia (OLK), 33 with oral squamous cell carcinoma (OSCC), and 15 healthy controls, were studied. By using microdissection method, we obtained normal mucosa, hyperplastic epithelia, mild-dysplastic epithelia, moderate-dysplastic epithelia, severe-dysplastic epithelia and primary OSCC tissue. Then we analyzed EMS1 amplification by using differential PCR.
RESULTSEMS1 amplification began from moderate-dysplastic epithelia and occurred in 20.0% OLK cases and 57.6% OSCC cases. In the progress of OSCC, no gene amplification was observed in normal tissues, non-dysplastic OLK and mild-dysplastic OLK, while in the cases with metastasis, amplification frequency increased significantly (P = 0.015).
CONCLUSIONSEMS1 amplification parallels with the progress of oral carcinogenesis, indicating their potential roles in oral carcinogenesis.
Carcinoma, Squamous Cell ; genetics ; pathology ; Case-Control Studies ; Cortactin ; genetics ; Gene Amplification ; Humans ; Leukoplakia, Oral ; genetics ; pathology