The chemical reprogramming of unipotent adult germ cells towards authentic pluripotency and de novo establishment of imprinting

Although somatic cells can be reprogrammed to pluripotent stem cells (PSCs) with pure chemicals, authentic pluripotency of chemically induced pluripotent stem cells (CiPSCs) has never been achieved through tetraploid complementation assay. Spontaneous reprogramming of spermatogonial stem cells (SSCs) was another non-transgenic way to obtain PSCs, but this process lacks mechanistic explanation. Here, we reconstructed the trajectory of mouse SSC reprogramming and developed a five-chemical combination, boosting the reprogramming efficiency by nearly 80- to 100-folds. More importantly, chemical induced germline-derived PSCs (5C-gPSCs), but not gPSCs and chemical induced pluripotent stem cells, had authentic pluripotency, as determined by tetraploid complementation. Mechanistically, SSCs traversed through an inverted pathway of in vivo germ cell development, exhibiting the expression signatures and DNA methylation dynamics from spermatogonia to primordial germ cells and further to epiblasts. Besides, SSC-specific imprinting control regions switched from biallelic methylated states to monoallelic methylated states by imprinting demethylation and then re-methylation on one of the two alleles in 5C-gPSCs, which was apparently distinct with the imprinting reprogramming in vivo as DNA methylation simultaneously occurred on both alleles. Our work sheds light on the unique regulatory network underpinning SSC reprogramming, providing insights to understand generic mechanisms for cell-fate decision and epigenetic-related disorders in regenerative medicine.

Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells / Análises de bioinformática e da expressão do gene Xeroderma Pigmentosum complementation group C (XPC) de Trypanosoma evansi em células de Trypanosoma cruzi

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells / Análises de bioinformática e da expressão do gene Xeroderma Pigmentosum complementation group C (XPC) de Trypanosoma evansi em células de Trypanosoma cruzi

Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T. cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T. cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

Identification and verification of α-11 giardin-interacting protein / 中国血吸虫病防治杂志

Objective To identify and verify the interacting protein of α-11 giardin, so as provide the experimental evidence for studies on the α-11 giardin function. Methods The yeast two-hybrid cDNA library of the Giardia lambia C2 strain and the bait plasmid of α-11 giardin were constructed. All proteins interacting with α-11 giardin were screened using the yeast two-hybrid system. α-11 giardin and all screened potential interacting protein genes were constructed into pBiFc-Vc-155 and pBiFc-Vn-173 plasmids, and co-transfected into the breast cancer cell line MDA-MB-231. The interactions between α-11 giardin and interacting proteins were verified using bimolecular fluorescence complementation (BiFC). Results The yeast two-hybrid G. lambia cDNA library which was quantified at 2.715 × 107 colony-forming units (CFU) and the bait plasmid containing α-11 giardin gene without an autoactivation activity were constructed. Following two-round positive screening with the yeast two-hybrid system, two potential proteins interacting with α-11 giardin were screened, including eukaryotic translation initiation factor 5A (EIF5A), calmodulin-dependent protein kinase (CAMKL) and nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH), hypothetical protein 1 (GL50803_95880), hypothetical protein 2 (GL50803_87261) and a protein from Giardia canis virus. The α-11 giardin and EIF5A genes were transfected into the pBiFc-Vc-155 and pBiFc-Vn-173 plasmids using BiFC, and the recombinant plasmids pBiFc-Vc-155-α-11 and pBiFc-Vn-173-EIF5A were co-tranfected into MDA-MB-231 cells, which displayed green fluorescence under a microscope, indicating the interaction between α-11 giardin and EIF5A protein in cells. Conclusion The yeast two-hybrid cDNA library of the G. lambia C2 strain has been successfully constructed, and six potential protein interacting with α-11 giardin have been identified, including EIF5A that interacts with α-11 giardin in cells.

Is excision repair cross-complementation Group1 expression a biological marker in nasopharynx carcinoma?

Objective: To determine the prognostic value of excision repairs cross-complementation group1 (ERCC1) gene in cases with nasopharyngeal carcinoma (NPC) treated with platinum-containing chemotherapy (PCT). Subjects and Methods: The present study was included 33 cases in local advanced stage with NPC. ERCC1 expression was evaluated by using immunohistochemical staining in biopsy specimens. We evaluated the relationship between the degree of ERCC1 expression and clinicopathological features, response to therapy, survival rates in cases with NPC, retrospectively. Results: ERCC1 expression was not observed in 5 (15.15%) of all cases. Thirteen (39.9%) cases weakly positive (+1, +2) and 15 (45.5%) cases of all them were rather strongly positive (+3). There was no statistically significant difference between the degree of ERCC1 expression and clinicopathological features, response to treatment, survival rates (P > 0.05) in cases with NPC. Conclusions: ERCC1 expression has no predictive value for survival in cases locally advanced stage with NPC. Evaluation of ERCC1 expression is not appropriate with a biomarker to detect cases who can benefit from PCT in NPC

Association of polymorphisms of xeroderma pigmentosum complementation group D gene with cervical cancer in Maharashtrian population: A case-control study

Background: Maharashtrian population is at the risk of cervical cancer (CC) and is not subjected to investigate the cancer susceptibility in association with genetic determinants. Objectives: This study was aimed to evaluate the association of single nucleotide polymorphisms (SNPs) in DNA repair gene xeroderma pigmentosum complementation group D (XPD) with CC risk from rural Maharashtra. Materials and Methods: We used polymerase chain reaction and-restriction fragment length polymorphism to analyze SNPs in XPD gene from 350 patients with CC and 400 age and sex-matched disease-free controls. Results: The results indicated no significant difference in the genotype distribution between CC patients and controls for the XPD gene at codon 156 of exon 6 and codon 751 of exon 23, but the results showed that allele frequencies of XPD Asn 312 of codon 312 of exon 10 (odds ratio = 0.31; 95% confidence intervals = [0.16–0.63]; P = <0.001) genotype showed negative association with CC risk. Conclusion: This study indicated the role of XPD (cd312) in modifying genetic susceptibility of an individual to CC in Maharashtrian patients.

Rapid generation of gene-targeted EPS-derived mouse models through tetraploid complementation

One major strategy to generate genetically modified mouse models is gene targeting in mouse embryonic stem (ES) cells, which is used to produce gene-targeted mice for wide applications in biomedicine. However, a major bottleneck in this approach is that the robustness of germline transmission of gene-targeted ES cells can be significantly reduced by their genetic and epigenetic instability after long-term culturing, which impairs the efficiency and robustness of mouse model generation. Recently, we have established a new type of pluripotent cells termed extended pluripotent stem (EPS) cells, which have superior developmental potency and robust germline competence compared to conventional mouse ES cells. In this study, we demonstrate that mouse EPS cells well maintain developmental potency and genetic stability after long-term passage. Based on gene targeting in mouse EPS cells, we established a new approach to directly and rapidly generate gene-targeted mouse models through tetraploid complementation, which could be accomplished in approximately 2 months. Importantly, using this approach, we successfully constructed mouse models in which the human interleukin 3 (IL3) or interleukin 6 (IL6) gene was knocked into its corresponding locus in the mouse genome. Our study demonstrates the feasibility of using mouse EPS cells to rapidly generate mouse models by gene targeting, which have great application potential in biomedical research.

Radiotherapy modulates expression of EGFR, ERCC1 and p53 in cervical cancer

Cervical cancer is a public health problem and the molecular mechanisms underlying radioresistance are still poorly understood. Here, we evaluated the modulation of key molecules involved in cell proliferation, cell cycle and DNA repair in cervical cancer cell lines (CASKI and C33A) and in malignant tissues biopsied from 10 patients before and after radiotherapy. The expression patterns of epidermal growth factor receptor (EGFR), excision repair cross-complementation group 1 (ERCC1) and p53 were evaluated in cancer cell lines by quantitative PCR and western blotting, and in human malignant tissues by immunohistochemistry. The mutation status of TP53 gene was evaluated by direct sequencing. Among cell lines, absent or weak modulations of EGFR, ERCC1 and p53 were observed after exposure to 1.8 Gy. Conversely, increased expressions of p53 (5/10 patients; P=0.0239), ERCC1 (5/10 patients; P=0.0294) and EGFR (4/10 patients; P=0.1773) were observed in malignant tissues after radiotherapy with the same radiation dose. TP53 mutations were found only in one patient. Here we show that a single dose of radiotherapy induced EGFR, ERCC1 and p53 expression in malignant tissues from cervical cancer patients but not in cancer cell lines, highlighting the gap between in vitro and in vivo experimental models. Studies on larger patient cohorts are needed to allow an interpretation that an upregulation of p53, EGFR and ERCC1 may be part of a radioresistance mechanism.

A Novel Rapid Fungal Promoter Analysis System Using the Phosphopantetheinyl Transferase Gene, npgA, in Aspergillus nidulans

To develop a convenient promoter analysis system for fungi, a null-pigment mutant (NPG) of Aspergillus nidulans was used with the 4′-phosphopantetheinyl transferase (PPTase) gene, npgA, which restores the normal pigmentation in A. nidulans, as a new reporter gene. The functional organization of serially deleted promoter regions of the A. nidulans trpC gene and the Cryphonectria parasitica crp gene in filamentous fungi was representatively investigated to establish a novel fungal promoter assay system that depends on color complementation of the NPG mutant with the PPTase npgA gene. Several promoter regions of the trpC and crp genes were fused to the npgA gene containing the 1,034-bp open reading frame and the 966-bp 3’ downstream region from the TAA, and the constructed fusions were introduced into the NPG mutant in A. nidulans to evaluate color recovery due to the transcriptional activity of the sequence elements. Serial deletion of the trpC and crp promoter regions in this PPTase reporter assay system reaffirmed results in previous reports by using the fungal transformation step without a laborious verification process. This approach suggests a more rapid and convenient system than conventional analyses for fungal gene expression studies.

Molecular cloning and characterization of 1-deoxy-D-xylulose 5-phosphate synthase gene from Taxus chinensis / 中草药

Objective To obatin the key enzymes of 1-deoxy-D-xylulose 5-phosphate synthase (DXS) in taxol biosynthetic pathway from Taxus chinensis (TcDXS), and carry out the bioinformatics analysis, tissue profile, subcellular localization, and functional complementation assay. Methods RACE technologies were used to obtain the full length cDNA of TcDXS for the bioinformatics analysis. Semi-quantitative PCR was used to detect the gene expression levels in different parts of T. chinensis. The localization and function of TcDXS were carried out by subcellular localization and functional complementation assay. Results The full-length cDNA of TcDXS was 3 031 bp containing a coding sequence of 2 229 bp encoding a 742-amino-acid residues which was predicted to have a molecular weight of 79 400 and an isoelectric point of 7.99. The qRT-PCR results showed that the highest expression level of TcDXS was detected in petioles and followed by leaves and barks. However, the expression of TcDXS was very low in roots and stems. What’s more, functional complementation assay results showed that the E. coli, co-transformed with PAC-BETA and pTrcTcDXS, was changed to orange. Conclusion TcDXS was considered to play an essential role in the control of taxol biosynthesis and provided a target for the metabolic engineering of taxol production and plant molecular breeding in T. chinensis.

Construction and application of Escherichia Coli-Riemerella anatipestifer efficient shuttle plasmid pFY02 / 生物工程学报

Riemerella anatipestifer is a pathogen that mainly infects ducks, gooses, turkeys and other birds, causing septicemia and serositis. At present, the function of R. anatipestifer genes are studied by gene deletion and complementation. However, the shuttle plasmid pLMF03 used at present is inefficient for conjugation. Moreover, less restriction enzyme site can be used for cloning. It is not able to use for all the genes complementation. To solve this disadvantage, the conjugative transfer site, R. anatipestifer replication initiation gene, high expression promoter and a number of enzyme cutting sites were cloned into the plasmid pPM5, to generate the new shuttle plasmid pFY02. The shuttle plasmid pFY02 was stable in R. anatipestifer and had a high conjugative transfer efficiency. The R. anatipestifer tonB2 mutant strain could be complemented by shuttle plasmid pFY02 expressing tonB2, indicating that the shuttle plasmid can be used to the complementation of R. anatipestifer. Taken together, the new shuttle plasmid pFY02 constructed in this study replenishes the genetic tool for complementation.

Physical interactions and mutational analysis of MoYpt7 in Magnaporthe oryzae / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

In this study, we analyzed the physical interactions of the dominant negative isoform of MoYpt7. Our results show that MoYpt7 interacts with MoGdi1. The dominant negative isoform of MoYpt7 (dominant negative isoform, N125I) is essential for colony morphology, conidiation, and pathogenicity in the rice blast fungus. These results further demonstrate the biological functions of MoYpt7 in Magnaporthe oryzae.

Stable expression of Mycobacterium bovis antigen 85B in auxotrophic M. bovis bacillus Calmette-Guérin

BACKGROUND Bovine tuberculosis (TB) is a zoonotic disease caused by Mycobacterium bovis, responsible for causing major losses in livestock. A cost effective alternative to control the disease could be herd vaccination. The bacillus Calmette-Guérin (BCG) vaccine has a limited efficacy against bovine TB, but can improved by over-expression of protective antigens. The M. bovis antigen 85B demonstrates ability to induce protective immune response against bovine TB in animal models. However, current systems for the construction of recombinant BCG expressing multiple copies of the gene result in strains of low genetic stability that rapidly lose the plasmid in vivo. Employing antibiotic resistance as selective markers, these systems also compromise vaccine safety. We previously reported the construction of a stable BCG expression system using auxotrophic complementation as a selectable marker. OBJECTIVES The fundamental aim of this study was to construct strains of M. bovis BCG Pasteur and the auxotrophic M. bovis BCG ΔleuD expressing Ag85B and determine their stability in vivo. METHODS Employing the auxotrophic system, we constructed rBCG strains that expressed M. bovis Ag85B and compared their stability with a conventional BCG strain in mice. Stability was measured in terms of bacterial growth on the selective medium and retention of antigen expression. FINDINGS The auxotrophic complementation system was highly stable after 18 weeks, even during in vivo growth, as the selective pressure and expression of antigen were maintained comparing to the conventional vector. MAIN CONCLUSION The Ag85B continuous expression within the host may generate a stronger and long-lasting immune response compared to conventional systems.

Molecular cloning and functional identification of a cDNA encoding 4-hydroxy-3-methylbut-2-enyl diphosphate reductase from

The 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR) is the last step key enzyme of the methylerythritol phosphate (MEP) pathway, synthesizing isopentenyl diphosphate and its allyl isomer dimethylallyl diphosphate, which is important for regulation of isoprenoid biosynthesis. Here the full-length cDNA of, designated(GenBank Accession No. KJ933412.1), was isolated fromfor the first time. TwHDR has an open reading frame (ORF) of 1386 bp encoding 461 amino acids. TwHDR exhibits high homology with HDRs of other plants, with an N-terminal conserved domain and three conserved cysteine residues.cDNA was cloned into an expression vector and transformed into anmutant. Since loss-of-functionmutant is lethal, the result showed that transformation ofcDNA rescued themutant. This complementation assay suggests that thecDNA encodes a functional HDR enzyme. The expression ofwas induced by methyl-jasmonate (MJ) insuspension cells. The expression ofreached the highest level after 1 h of MJ treatment. These results indicate that we have identified a functional TwHDR enzyme, which may play a pivotal role in the biosynthesis of diterpenoid triptolide in.

Clinical significance of the expression levels of ERCC1, BRCA1 and TS in advanced colorectal cancer / 中国医师进修杂志

Objective To explore the relationship between the expression levels of excision repair cross complementation group 1(ERCC1), breast cancer susceptibility gene 1(BRCA1), thymidylate synthase (TS) mRNA and clinicopathological features, prognosis in advanced colorectal cancer, and the correlation between the expression levels of ERCC1 and BRCA1. Methods The expression levels of ERCC1, BRCA1 and TS mRNA of postoperative paraffin embedded tissue were tested by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) in 49 advanced colorectal cancer cases. The results were analyzed by χ2 test of the correlation between the expression levels and clinicopathological characteristics. Patients were followed up by clinic or telephone. The prognosis was analyzed by small sample Kaplan-Meier survival analysis and Log-rank time series analysis, and P0.05). The expression level of BRCA1 mRNA had no significant correlation with the above clinical and pathological features (P>0.05) except distant metastasis (P=0.030) and differentiation degree (P=0.002). The expression level of TS mRNA had no significant correlation with the above clinical and pathological features (P>0.05) except distant metastasis (P=0.003). The expression level of ERCC1 and BRCA1 mRNA obviously correlated (P=0.002). The 1 year overall survival rate was 95.92%(47/49);the 2 year overall survival rate was 83.67%(41/49);and the 3 year overall survival rate was 73.47%(36/49). Overall survival and progression-free survival time in ERCC1 mRNA low expression group (47.8, 41.0 months) was higher than that in ERCC1 mRNA low expression group (27.3, 20.0 months) respectively (P=0.001, P=0.001). Overall survival and progression-free survival time in BRCA1 mRNA low expression group (43.7, 42.7 months) was higher than that in BRCA1 mRNA high expression group (29.3, 25.1 months) respectively (P=0.009, 0.006). Overall survival time in TS mRNA low expression group (39.8 months) was higher than that in BRCA1 mRNA high expression group (25.2 months). Conclusions The expression level of ERCC1 mRNA is not correlated with its clinical and pathological characteristics, but with its biological characteristics. BRCA1 and TS levels are correlated with invasion and metastasis. Low levels of ERCC1 and BRCA1 expression have a better prognostic effect on platinum based first-line chemotherapy for advanced colorectal cancer, and they are correlated. Low level of TS also has longer disease-free survival. Three joint detection could be used as a prognostic factor for colorectal cancer chemotherapy.

ERCC1-shRNA inhibits the proliferation and promotes the apoptosis of lung cancer A549/DDP cells / 医学研究生学报

Objective Studies show that the ERCC1 gene may be involved in secondary cisplatin resistance.This article aims to investigate the effects of shRNA targeting silencing excision repair cross-complementation group 1 (ERCC1-shRNA) on the proliferation and apoptosis of lung cancer A549/DDP cells treated with different concentrations of cisplatin.Methods Lung cancer A549/DDP cells were divided into a negative control, a blank control, an ERCC1-shRNA1, and an ERCC1-shRNA2 group.Human interfering RNA (RNAi) targeting the human ERCC1 gene was constructed and transfected into the A549/DDP cells using Lipofectamine 2000.The mRNA and protein expressions of ERCC1 in the A549/DDP cells were detected by real-time PCR and Western blot respectively, the proliferation-inhibition rate was assessed by MTT, and their cell cycle and apoptosis were determined by flow cytometry.Results ERCC1-shRNA was successfully constructed and transfected into the A549/DDP cells.Both the mRNA and protein expressions of ERCC1 were significantly lower in the ERCC1-shRNA1 (0.20±0.04 and 0.24±0.10) and ERCC1-shRNA2 (0.47±0.28 and 0.37±0.11) than in the negative control (0.96±0.12 and 1.32±0.13) and blank control groups (0.84±0.07 and 1.45±0.23) (P<0.01).Compared with the negative and blank control groups, the ERCC1-shRNA1 group showed a significantly decreased IC50 value (16.71±2.33 and 16.69±1.69 vs 7.78±0.54, P<0.01) and an increased proportion of G0/G1 phase cells ([72.87±3.23] and [71.75±4.56] vs [82.99±4.23]%, P<0.05), with the cell cycle arrested in the G0/G1 phase.The apoptosis rate of the cells in the ERCC1-shRNA1 group was remarkably lower after treated with cisplatin at the concentrations of 6.25 and 12.5 μg/mL than at 0 μg/mL ([8.17±0.65] and [11.91±1.41] vs [29.97±3.14]%, P<0.05).Conclusion ERCC1-shRNA can inhibit the proliferation and enhance the apoptosis of A549/DDP cells by silencing the expression of the ERCC1 gene.

Cell-to-cell Transmission of Polyglutamine Aggregates in C. elegans

Huntington disease (HD) is an inherited neurodegenerative disorder characterized by motor and cognitive dysfunction caused by expansion of polyglutamine (polyQ) repeat in exon 1 of huntingtin (HTT). In patients, the number of glutamine residues in polyQ tracts are over 35, and it is correlated with age of onset, severity, and disease progression. Expansion of polyQ increases the propensity for HTT protein aggregation, process known to be implicated in neurodegeneration. These pathological aggregates can be transmitted from neuron to another neuron, and this process may explain the pathological spreading of polyQ aggregates. Here, we developed an in vivo model for studying transmission of polyQ aggregates in a highly quantitative manner in real time. HTT exon 1 with expanded polyQ was fused with either N-terminal or C-terminal fragments of Venus fluorescence protein and expressed in pharyngeal muscles and associated neurons, respectively, of C. elegans. Transmission of polyQ proteins was detected using bimolecular fluorescence complementation (BiFC). Mutant polyQ (Q97) was transmitted much more efficiently than wild type polyQ (Q25) and forms numerous inclusion bodies as well. The transmission of Q97 was gradually increased with aging of animal. The animals with polyQ transmission exhibited degenerative phenotypes, such as nerve degeneration, impaired pharyngeal pumping behavior, and reduced life span. The C. elegans model presented here would be a useful in vivo model system for the study of polyQ aggregate propagation and might be applied to the screening of genetic and chemical modifiers of the propagation.

Correlation of TS, ERCC1,β-tubulin-Ⅲ and RRM1 expressions with EGFR mutations in non-small cell lung cancer / 医学研究生学报

Objective Currently , the targeted therapy is the first-choice treatment of advanced non-small cell lung cancer (NSCLC) in with epidermal growth factor receptor (EGFR) mutations, but few studies have been reported on the relationship between immunohistochemical markers and the EGFR mutation.The aim of this study is to analyze the relationship of the EGFR mutation with the ex-pressions of thymidylate synthetase (TS), excision repair cross-com-plementation group 1 ( ERCC1 ) , β-tubulin-III, and ribonucleofide reductase large subunit-l ( RRM1) in NSCLC. Methods We retro-spectively analyzed 336 cases of NSCLC treated in the Department of Medical Oncology , the Affiliated Hospital of Inner Mongolia Medical University, from June 2014 to December 2015 and examined 29 EGFR mutations.We divided the patients into a mutation and a non-mutation group, performed immunohistochemical staining of the TS, ERCC1,β-tubulin-III and RRM1 proteins and compared their expressions in the NSCLC tissue between the two groups . Results EGFR mutations were found in 138 ( 41.07%) of the 336 NSCLC patients but not in the other 198 ( 58.93%) .The expression of TS was significantly lower in the mutation than in the non-mutation group (9.42%vs 39.39%, P<0.05), and so was that of β-tubulin-III (44.2%vs 60.1%, P<0.05).EGFR mutations were correlated with decreased expressions of TS (r=-0.332, P<0.05) andβ-tubulin-III (r=-0.157, P<0.05).Multivariate regression analysis showed that the risk of EGFR mutations was 2.109 times higher in the fe-male patients than in the males (OR=2.109, 95%CI:1.268-3.509), 24.265 times higher in the adenocarcinoma than in the adeno-squamous carcinoma patients (OR=24.265, 95%CI:3.508-167.845), 15.2 times higher in the squamous carcinoma than in the ade-nocarcinoma patients (OR=15.200, 95%CI:4.480-51.569), 2.364 times higher in the lung biopsy specimens than in the surgically treated patients (OR=2.364, 95%CI:1.266-4.413), and 6.171 times higher in the patients with lowly expressed than in those with highly expressed TS (OR=6.171, 95%CI: 3.145-12.109). Conclusion The decreased expressions of TS and β-tubulin-Ⅲ in NSCLC indicate the mutation of the EGFR gene.

Association between XPC Lys939Gln (A/C) gene polymorphism and the susceptibility of gastric cancer:a Meta-analysis / 国际肿瘤学杂志

Objective To explore the association between Xeroderma pigmentosum complementation C group (XPC) Lys939Gln (A/C) gene polymorphism and the susceptibility of gastric cancer.Methods By searching PubMed,Cochrane Library,Elsevier,Springer-Verlag,China National Knowledge Infrastructure,Chinese Biomedical Literature Data,VIP Database and Wanfang Database,all eligible case-control studies published up to September 2015 were selected and the quality of each article was valuated by two reviewers independently according to the inclusion and exclusion criteria.Meta-analysis was performed by using STATA 12.0 software.Odds ratio (OR) and 95％ confidence interval (CI) were calculated.The text was estimated for the subgroup analysis,sensitivity analysis and publication bias test.Results A total of 7 case-control studies were included,including 2 336 cases with gastric cancer and 3 502 controls.The Meta-analysis showed that compared with the allele A,the allele C increased the risk of gastric cancer (OR =1.09,95％ CI:1.01-1.18,Z =2.12,P =0.034);compared to the genotype AA,the homozygous model (CC) and dominant model (CC + AC) also increased the risk of gastric cancer (CC vs.AA:OR =1.19,95％ CI:1.00-1.42,Z =2.00,P=0.046;CC+ACvs.AA:OR=1.12,95％CI:1.00-1.25,Z=2.03,P=0.042).The Meta-analysis showed the statistical significance between XPC Lys939Gln (A/C) gene polymorphism and the gastric cancer risk in subgroup of Asian people (C vs.A:OR =1.10,95％ CI:1.01-1.20,Z =2.28,P =0.023;CC vs.AA:OR=l.21,95％CI:1.01-1.46,Z=2.02,P=0.043;CC +AC vs.AA:OR =1.13,95％ CI:1.01-1.27,Z =2.11,P =0.035) and the source of community in the control group (C vs.A:OR =1.11,95％ CI:1.01-1.21,Z=2.25,P =0.024;CC vs.AA:OR =1.23,95％ CI:1.02-1.50,Z =2.12,P =0.034).Conclusion XPC Lys939G1n (A/C) gene polymorphism may be associated with the susceptibility of gastric cancer,and genotype CC,CC + AC and allele C can increase the risk of gastric cancer.