ABSTRACT
Objective@#To explore the prognostic value of human mitochondrial transcription termination factor 3 (hMTERF3) and forkhead box protein 3 (Foxp3) in non-small cell lung cancer (NSCLC).@*Methods@#The clinical data of 88 patients with NSCLC who were admitted to the Third Medical Center of PLA General Hospital from March 2017 to March 2018 were retrospectively analyzed. All patients were diagnosed by pathological puncture. The patients were followed-up by telephone for 12 months, and according to the prognosis, the patients were divided into good prognosis group and poor prognosis group. The pathological tissues were taken from all patients, and the expressions of hMTERF3 and Foxp3 proteins were detected by immunohistochemistry. The expressions of hMTERF3 and Foxp3 in the good prognosis group and the poor prognosis group were compared. Logistic regression model was used to analyze the risk factors of poor prognosis in patients with NSCLC.@*Results@#Of 88 patients, 61 patients (69.3%) had good prognosis and 27 patients (30.7%) had poor prognosis. The positive expression rate of hMTERF3 in the good prognosis group was 57.4% (35/61), which was significantly lower than that in the poor prognosis group (81.5%, 22/27) (χ 2= 4.766, P= 0.029). The positive expression rate of Foxp3 in the good prognosis group was 55.7% (34/61), which was significantly lower than that in the poor prognosis group (85.2%, 23/27) (χ 2= 7.113, P= 0.008). The proportions of patients with medium and high differentiation or stage Ⅰ- Ⅱ in the good prognosis group were 82.0% (50/61) and 68.8% (42/61), respectively, which were significantly higher than those in the poor prognosis group [48.15% (13/27) and 25.93% (7/27)] (both P < 0.05). Logistic regression analysis showed that the poor differentiation, stage Ⅲ-Ⅳ, hMTERF3-positive and Foxp3-positive were the risk factors for poor prognosis in NSCLC patients (all P < 0.05).@*Conclusions@#The positive expression rates of hMTERF3 and Foxp3 in patients with good prognosis are lower. The hMTERF3-positive and Foxp3-positive are risk factors for poor prognosis in NSCLC patients.
ABSTRACT
Objective The purpose of this study was to investigate the expression of human mitochondrial transcription termi-nation factor-3 ( hMTERF3) in non-small cell lung cancer ( NSCLS) and to analyze its clinicopathological significance. Methods The paraffin block samples used in this study included 65 cases of NSCLC and 32 cases of normal alveolar epithelial tissues. We determined the expressions of hMTERF3 in NSCLC and normal alveolar epithelial tis-sues by immunohistochemistry, calculate the survival rate using the Kaplan-Meier method, and analyzed the risk factors affecting the prognosis of NSCLC using the Cox Proportional Hazard Model. Results In the 65 cases of NSCLC, 31 ( 47. 69%) showed positive expression of hMTERF3. The total survival time was significantly shor-ter in the patients with a high than in those with a low hMTERF3 ex-pression ([30.39±3.35] vs [57.61±7.12] mo, P<0.05). The riskfactors affecting the prognosis of NSCLC included positive expression of hMTERF3 (HR=3.302, 95% CI:1.598-6.905) and lymph node metastasis (HR=4.052, 95% CI: 1.212-12.398). Conclusion hMTERF3 is overexpressed in NSCLC. Highly expressed hMTERF3 and lymph node metastasis reduce the survival time of NSCLC patients, suggesting that hMTERF3 may be a potential bio-marker for the prognosis of NSCLC.
ABSTRACT
Objective To investigate the expression of mitochondrial transcription termination factors (MTERFs) in various tissues and cells, and the changes of MTERFs induced by l-methyl-4-phenyl-l, 2, 3, 6-tetrahydropyridine (MPTP)/l-methyl-4-pheny lpyridine (MPP+). Methods Western blotting was used to measure the expression of the MTERFs in brain, liver, kidney of C57BL mice and in human SH-SY5Y, HCM, L-02 cells. MPTP/MPP+ was injected to imitate PD animal/cell models. The changes of MTERFs protein were detected through western blotting. Results The expression of MTERFs was higher in mice brain and SH-SY5Y cells. In PD mouse model induced by MPTP, MTERF3 reduced significantly. Conclusion The expression of MTERFs was higher in mouse brain and SH-SY5Y cells. After induced by MPTP/MPP+, MTERF3 decreased obviously, which increased transcription level and might involve in a process of Parkinsons disease.
ABSTRACT
Objective The proteins encoded by mitochondrial transcription termination factor 1 ( MTERF1) plays important roles in regulating the mitochondrial gene expression and oxidative phosphorylation .This study was to investigate the characteristics and regulation mechanisms of the human MTERF1 gene with bioinformatics tools . Methods Using online bioinformatics software and phylogenetic foot-printing, we analyzed the promoter distribution , GpG island, transcription factors , and binding sites of the human MTERF1 gene. Results The human MTERF1 gene was located on 7q21.2, with a full length of 7845 bp, consisting of 4 exons and 3 introns.There were at least 2 promoters in the 5′region of the gene.The core promoter of the MTERF1 gene was located between 1878 and 2447 bp, which played a key role in its transcription .An 812 bp CpG island was observed in the gene promoter region .In addi-tion, 26 transcription factor binding sites were found in the conserved promoter region of human and mouse homologous MTERF1 genes. Conclusion Gene promoter-related online bioinformatics software can improve the efficiency of human MTERF1 gene promoter resear-ches and provide significant information for the prediction of gene pro-moter function.
ABSTRACT
Objective Human mitochondrial transcription termination factor 3 ( MTERF3 ) is a negative regulator of mito?chondrial gene expression and energy metabolism. This study was to construct a prokaryotic expression system for MTERF3 in Esche?richia coli ( E. coli ) and prepare its mouse?anti?human polyclonal antibody. Methods The complete open reading frame ( ORF) of human MTERF3 cDNA was amplified by RT?PCR and subcloned into prokaryotic expression vector pET28b. Then the recombinant plasmid pET28b?MTERF3 was transformed into competent E.coli BL21(DE3) and IPTG induced the expression of 6×his fusion protein. The recom?binant human MTERF3 protein was purified through Ni2+?NTA agar?ose gel column affinity chromatography and the purified recombinant protein was used as immunogen to immunize the BALB/c mice to pre?pare its specific polyclonal antibody. The titer and specificity of the antibody were analyzed by ELISA, Western blot and cellular immuno?fluorescence, respectively. Results The recombinant human MTERF3 protein was successfully expressed in E. coil and the mouse?anti?human MTERF3 polyclonal antibody with high quality was successfully prepared. ELISA showed that the titer of the antibody was 1:105 . Western blot and immunofluorescence detection revealed that the mouse?anti?human MTERF3 antibody could recognize the native MTERF3 antigen specifically. Conclusion Human MTERF3 expressed in the prokaryotic system has strong immunogenicity and the polyclonal antibody obtained from immunizing mice has high titer and specificity. The prokaryotic expression of human MTERF3 and the preparation of its antibody lay the foundation for further function research of human MTERF3.
ABSTRACT
Many horizontally acquired genes (xenogenes) in the bacterium Escherichia coli are maintained in a silent transcriptional state by the nucleoid-associated transcription regulatory protein H-NS. Recent evidence has shown that antibiotic-mediated inhibition of the transcription terminator protein Rho leads to de-repression of horizontally acquired genes, akin to a deletion of hns. The mechanism behind this similarity in outcomes between the perturbations of two distinct processes remains unclear. Using ChIP-seq of H-NS in wild-type cells, in addition to that in cells treated with bicyclomycin – a specific inhibitor of Rho, we show that bicyclomycin treatment leads to a decrease in binding signal for H-NS to the E. coli chromosome. Rho inhibition leads to RNA polymerase readthrough, which in principle could displace H-NS from the DNA, thus leading to transcriptional derepression of H-NS-silenced genes. Other possible mediators of the effect of Rho on H-NS are discussed. A possible positive feedback between Rho and H-NS might help reinforce xenogene silencing.
ABSTRACT
The retrotransposon known as long interspersed nuclear element-1 (L1) is 6 kb long, although most L1s in mammalian and other eukaryotic cells are truncated. L1 contains two open reading frames, ORF1 and ORF2, that code for an RNA-binding protein and a protein with endonuclease and reverse transcriptase activities, respectively. In this work, we examined the effects of full length L1-ORF2 and ORF2 fragments on green fluorescent protein gene (GFP) expression when inserted into the pEGFP-C1 vector downstream of GFP. All of the ORF2 fragments in sense orientation inhibited GFP expression more than when in antisense orientation, which suggests that small ORF2 fragments contribute to the distinct inhibitory effects of this ORF on gene expression. These results provide the first evidence that different 280-bp fragments have distinct effects on the termination of gene transcription, and that when inserted in the antisense direction, fragment 280-9 (the 3' end fragment of ORF2) induces premature termination of transcription that is consistent with the effect of ORF2.
ABSTRACT
Autoregulation of the rho gene insures a controlled level of a critical gene product independent of cellular changes. We have investigated the autoregulation of rho, the gene that encodes the transcription termination factor, rho. In a DNA dependent in vitro coupled transcription-translation system, rho represses its own synthesis, confirming the autoregulatory nature of rho. srho is believed to perform its negative regulatory role by modulating transcription termination at an early site in the operon.