转录调节蛋白TP 53(Tumor protein 53)调控多种重要生物学过程,包括细胞周期、DNA损伤、修复和细胞凋亡等.在各种应激条件下tp53会被激活并发挥与应激相关的调控作用,但tp53在鱼类低温应激下的作用尚不明了.本文首先检测在低温应激条件...转录调节蛋白TP 53(Tumor protein 53)调控多种重要生物学过程,包括细胞周期、DNA损伤、修复和细胞凋亡等.在各种应激条件下tp53会被激活并发挥与应激相关的调控作用,但tp53在鱼类低温应激下的作用尚不明了.本文首先检测在低温应激条件下斑马鱼(Danio rerio)中tp53的表达变化,然后利用tp53^(-/-)斑马鱼敲除模型研究了敲除tp53对斑马鱼低温耐受能力和运动的影响.RT-qPCR结果显示:在8℃低温条件下野生型斑马鱼全鱼和鳃组织中tp53的mRNA水平显著升高.低温耐受实验显示:8℃低温下tp53^(-/-)斑马鱼的耐受能力增强,半数致死时间(lethal time to 50%mortality, LT50)显著高于WT(Wild type)对照组(P<0.000 1).运动行为学实验发现:与28℃相比,18℃低温下WT和tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著降低(P<0.000 1);同时发现在28℃和18℃条件下,tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著高于WT组.研究结果说明tp53参与斑马鱼的低温响应过程,敲除tp53后斑马鱼的耐寒能力与运动能力增强.本文为鱼类的低温耐受机制和运动行为学研究提供了新思路.展开更多
以高秆突变体高秆1号为试验材料,常规品种N099为对照,利用酶联免疫法测定突变体种子浸泡24 h后种胚中激素含量。结果表明,高秆1号的3种激素GA3、ZR、IAA的含量均高于对照,其中GA3的含量显著高于对照。杂交F1表现为:GA3含量显著高于两亲...以高秆突变体高秆1号为试验材料,常规品种N099为对照,利用酶联免疫法测定突变体种子浸泡24 h后种胚中激素含量。结果表明,高秆1号的3种激素GA3、ZR、IAA的含量均高于对照,其中GA3的含量显著高于对照。杂交F1表现为:GA3含量显著高于两亲本,但ZR、IAA含量比正常株高亲本还要低。这暗示高秆1号是一种GA3富集型突变体;而与ZR、IAA关联不大。采用陆陆杂交群体对高秆基因进行染色体定位,有4个SSR分子标记与Tp基因连锁,分别是NAU2083、NAU4045、NAU2419和NAU4044,位于Tp基因两侧的分子标记为NAU4045和NAU2419,其遗传距离分别为7.4 c M和41.2 c M。由此,将陆地棉的一个高秆突变体基因Tp定位在棉花Chr.1上。展开更多
AIM： To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TPS3 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H...AIM： To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TPS3 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H pylori infection. METHODS： Gastric biopsies from normal mucosa （NM, n = 10）, chronic gastritis （CG, n = 38）, atrophic gastritis （CAG, n=13） and gastric ulcer （GU, n=21） were studied using fluorescence in situ hybridization （FISH） and immunohistochemical assay. A modified Giemsa staining technique and PCR were used to detect Hpylori. An association of the gastric pathologies and aneuploidies with Hpylori infection was assessed. RESULTS： Aneuploidies were increasingly found from CG （21%） to CAG （31%） and to GU （62%）, involving mainly monosomy and trisomy 7, trisomies 7 and 8, and trisomies 7, 8 and 17, respectively. A significant association was found between H pylori infection and aneuploidies in CAG （P=0.0143） and GU （P=0.0498）. No TP53 deletion was found in these gastric lesions, but p53-positive immunoreactivity was detected in 45% （5/11） and 12% （2/17） of CG and GU cases, respectively. However, there was no significant association between p53 expression and H pylori infection. CONCLUSION： The occurrence of aneuploidies in benign lesions evidences chromosomal instability in early stages of gastric carcinogenesis associated with Hpylori infection, which may confer proliferative advantage. The increase of p53 protein expression in CG and GU may be due to overproduction of the wild-type protein related to an inflammatory response in mucosa.展开更多
BACKGROUND Although the role of p53 in the evolution and prognosis of gastric cancer(GC)has been extensively examined,the exact mechanism of action is incompletely understood.In the last years,p53-target genes were su...BACKGROUND Although the role of p53 in the evolution and prognosis of gastric cancer(GC)has been extensively examined,the exact mechanism of action is incompletely understood.In the last years,p53-target genes were supposed to be involved in the p53 pathway.One of them is the tumor-suppressor gene Maspin,which codifies the protein with the same name.Maspin activity depends on its subcellular localization.To our knowledge,the possible role of TP53 gene in Maspin subcellular localization,in GC cells,has not yet been studied in a large number of human samples.AIM To evaluate the possible role of wild-type and mutated p53 in Maspin subcellular localization.METHODS The present study included 266 consecutive patients with GC in which TP53 gene status,and mutations in exons 2 to 11,respectively,were analyzed and correlated with immunohistochemical expression of p53 and Maspin.RESULTS None of the 266 cases showed mutations in exon 9.The rate of TP53 mutations was 33.83%.The mutation rate was slightly higher in distally-located GCs,with a lower degree(≤5 buds/high power fields)of dyscohesivity(P<0.01).The wildtype cases had a longer survival,compared with mutant GCs,especially in patients without lymph node metastases,despite the high depth of tumor infiltration(P=0.01).The Dukes-MAC-like staging system was proved to have the most significant independent prognostic value(P<0.01).The statistical correlations proved that TP53 gene mutations in exon 7 might induce knockdown of Maspin,but wild-type p53 can partially restore nuclear Maspin expression and decrease the metastatic potential of gastric adenocarcinoma cells.CONCLUSION Downregulated Maspin might be induced by mutations in exon 7 of the TP53 gene but wild-type p53 can partially restore nuclear Maspin expression.These findings should be proved in experimental studies.展开更多
To construct the recombinant plasmid of eukaryotic expression containing Tp92 gene from Treponema pallidum and study its immunogenicity in New Zealand white rabbits. Tp92 gene was amplified from the genomic DNA of T. ...To construct the recombinant plasmid of eukaryotic expression containing Tp92 gene from Treponema pallidum and study its immunogenicity in New Zealand white rabbits. Tp92 gene was amplified from the genomic DNA of T. pallidum by polymerase chain reaction (PCR) and subcloned into appropriate site of pcDNA3.1(+) vector. After identification by sequencing and restrictive enzyme digestion, the recombinant plasmid was transfected into HeLa cells using liposome, and the expressed protein was identified by immunocytochemistry and Western blotting. After verifying that the Tp92 antigen gene fragment could be expressed in HeLa cells, 100?μg of recombinant plasmids [pcDNA3.1(+)-Tp92], 100 μg of control plasmids [pcDNA3.1(+)] or 0.5 ml PBS buffer were administered in 3 groups of New Zealand white rabbits (6 rabbits/group), and the booster immunizations were employed at 2-week interval for 3 times. ELISA assay was used for the quantitative detection of the specific antibody in the sera of rabbits, and the proliferation response of spleen cells was detected by MTT assay. It was found that the target gene Tp92 segment about 2103 bp was obtained, and the DNA sequence of Tp92 gene constructed in pcDNA3.1 (+) vector was consistent with the published nucleotide sequence. The homologies of the nucleotide and putative amino acid sequences of Tp92 gene between T.pallidum subsp. pallidum Nichols and various pathogenic treponeme strains were 95.5%-100%. The analysis of immunocytochemistry and Western blotting showed that Tp92 gene segment constructed in pcDNA3.1(+) vector could express a fusion protein with a calculated molecular mass of 77 kDa in HeLa cells and the expressed protein could react with positive blood serum from syphilis patient. The specific antibody IgG titers were observed and the highest titer was 1∶1024 in rabbits after 3 times with pcDNA3.1(+)-Tp92. The proliferation response of spleen cells were significantly higher than that of rabbits injected with pcDNA3.1(+) ( P <0.05). The successful expression of the eukaryotic expression plasmid of Tp92 gene from T. pallidum was obtained in eukaryotic system and strong responses of humoral and cellular immunity was evoked by DNA vaccine of pcDNA3.1(+)-Tp92 in rabbits thus establishing a solid basis for the future studies in the biological activities and for the development of the syphilis DNA vaccine.展开更多
Osteosarcoma is a rare and highly malignant tumor that usually affects adolescents and young adults. Despite current management protocols, up to half of patients succumb to the disease. Moreover, there is no well-char...Osteosarcoma is a rare and highly malignant tumor that usually affects adolescents and young adults. Despite current management protocols, up to half of patients succumb to the disease. Moreover, there is no well-characterized molecular marker for diagnosis and prognosis. TP53 alterations have been associated with a poor prognosis in many cancers. The aim of this retrospective work was to find out whether TP53 functional status predicts response to neoadjuvant chemotherapy and thus may help treatment decision for osteosarcoma patients. Seventeen biopsies of osteosarcoma patients receiving primary metotrexate, cisplatin and adryamicin chemotherapy followed by surgery were analyzed. TP53 exons 5-9 mutations were screened. Among 17 biopsies, 4 (23.5%) displayed TP53 mutations: 3 deletions and one single-nucleotide substitution. The presence of TP53 gene mutation does not correlate with resistance to chemotherapy according to histological Rosen grade and nevertheless is associated with patient’s age in a significant manner (p 0.05). The presence of non-mutated TP53 is not entirely specific for a good prognosis. We found no evidence that TP53 mutations predict chemoresistance in osteosarcoma patients more over the overall survival curve, followed for more than 12 years, showing no difference between patients with tumors harboring wild type or mutated TP53 gene (p 0.5). Further analysis to identify other genes that can influence chemotherapy response and clinical outcome in osteosarcoma is needed to improve patient treatment.展开更多
文摘转录调节蛋白TP 53(Tumor protein 53)调控多种重要生物学过程,包括细胞周期、DNA损伤、修复和细胞凋亡等.在各种应激条件下tp53会被激活并发挥与应激相关的调控作用,但tp53在鱼类低温应激下的作用尚不明了.本文首先检测在低温应激条件下斑马鱼(Danio rerio)中tp53的表达变化,然后利用tp53^(-/-)斑马鱼敲除模型研究了敲除tp53对斑马鱼低温耐受能力和运动的影响.RT-qPCR结果显示:在8℃低温条件下野生型斑马鱼全鱼和鳃组织中tp53的mRNA水平显著升高.低温耐受实验显示:8℃低温下tp53^(-/-)斑马鱼的耐受能力增强,半数致死时间(lethal time to 50%mortality, LT50)显著高于WT(Wild type)对照组(P<0.000 1).运动行为学实验发现:与28℃相比,18℃低温下WT和tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著降低(P<0.000 1);同时发现在28℃和18℃条件下,tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著高于WT组.研究结果说明tp53参与斑马鱼的低温响应过程,敲除tp53后斑马鱼的耐寒能力与运动能力增强.本文为鱼类的低温耐受机制和运动行为学研究提供了新思路.
文摘以高秆突变体高秆1号为试验材料,常规品种N099为对照,利用酶联免疫法测定突变体种子浸泡24 h后种胚中激素含量。结果表明,高秆1号的3种激素GA3、ZR、IAA的含量均高于对照,其中GA3的含量显著高于对照。杂交F1表现为:GA3含量显著高于两亲本,但ZR、IAA含量比正常株高亲本还要低。这暗示高秆1号是一种GA3富集型突变体;而与ZR、IAA关联不大。采用陆陆杂交群体对高秆基因进行染色体定位,有4个SSR分子标记与Tp基因连锁,分别是NAU2083、NAU4045、NAU2419和NAU4044,位于Tp基因两侧的分子标记为NAU4045和NAU2419,其遗传距离分别为7.4 c M和41.2 c M。由此,将陆地棉的一个高秆突变体基因Tp定位在棉花Chr.1上。
基金Supported by the Brazilian Agency FAPESP,No.00/09413-6
文摘AIM： To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TPS3 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H pylori infection. METHODS： Gastric biopsies from normal mucosa （NM, n = 10）, chronic gastritis （CG, n = 38）, atrophic gastritis （CAG, n=13） and gastric ulcer （GU, n=21） were studied using fluorescence in situ hybridization （FISH） and immunohistochemical assay. A modified Giemsa staining technique and PCR were used to detect Hpylori. An association of the gastric pathologies and aneuploidies with Hpylori infection was assessed. RESULTS： Aneuploidies were increasingly found from CG （21%） to CAG （31%） and to GU （62%）, involving mainly monosomy and trisomy 7, trisomies 7 and 8, and trisomies 7, 8 and 17, respectively. A significant association was found between H pylori infection and aneuploidies in CAG （P=0.0143） and GU （P=0.0498）. No TP53 deletion was found in these gastric lesions, but p53-positive immunoreactivity was detected in 45% （5/11） and 12% （2/17） of CG and GU cases, respectively. However, there was no significant association between p53 expression and H pylori infection. CONCLUSION： The occurrence of aneuploidies in benign lesions evidences chromosomal instability in early stages of gastric carcinogenesis associated with Hpylori infection, which may confer proliferative advantage. The increase of p53 protein expression in CG and GU may be due to overproduction of the wild-type protein related to an inflammatory response in mucosa.
基金the Romanian National Authority for Scientific ResearchNo.20 PCCF/2018。
文摘BACKGROUND Although the role of p53 in the evolution and prognosis of gastric cancer(GC)has been extensively examined,the exact mechanism of action is incompletely understood.In the last years,p53-target genes were supposed to be involved in the p53 pathway.One of them is the tumor-suppressor gene Maspin,which codifies the protein with the same name.Maspin activity depends on its subcellular localization.To our knowledge,the possible role of TP53 gene in Maspin subcellular localization,in GC cells,has not yet been studied in a large number of human samples.AIM To evaluate the possible role of wild-type and mutated p53 in Maspin subcellular localization.METHODS The present study included 266 consecutive patients with GC in which TP53 gene status,and mutations in exons 2 to 11,respectively,were analyzed and correlated with immunohistochemical expression of p53 and Maspin.RESULTS None of the 266 cases showed mutations in exon 9.The rate of TP53 mutations was 33.83%.The mutation rate was slightly higher in distally-located GCs,with a lower degree(≤5 buds/high power fields)of dyscohesivity(P<0.01).The wildtype cases had a longer survival,compared with mutant GCs,especially in patients without lymph node metastases,despite the high depth of tumor infiltration(P=0.01).The Dukes-MAC-like staging system was proved to have the most significant independent prognostic value(P<0.01).The statistical correlations proved that TP53 gene mutations in exon 7 might induce knockdown of Maspin,but wild-type p53 can partially restore nuclear Maspin expression and decrease the metastatic potential of gastric adenocarcinoma cells.CONCLUSION Downregulated Maspin might be induced by mutations in exon 7 of the TP53 gene but wild-type p53 can partially restore nuclear Maspin expression.These findings should be proved in experimental studies.
基金This work was supported by Hunan Provincial Education Department (002A046) and Department of Public Health of Hunan province (B2003 085)
文摘To construct the recombinant plasmid of eukaryotic expression containing Tp92 gene from Treponema pallidum and study its immunogenicity in New Zealand white rabbits. Tp92 gene was amplified from the genomic DNA of T. pallidum by polymerase chain reaction (PCR) and subcloned into appropriate site of pcDNA3.1(+) vector. After identification by sequencing and restrictive enzyme digestion, the recombinant plasmid was transfected into HeLa cells using liposome, and the expressed protein was identified by immunocytochemistry and Western blotting. After verifying that the Tp92 antigen gene fragment could be expressed in HeLa cells, 100?μg of recombinant plasmids [pcDNA3.1(+)-Tp92], 100 μg of control plasmids [pcDNA3.1(+)] or 0.5 ml PBS buffer were administered in 3 groups of New Zealand white rabbits (6 rabbits/group), and the booster immunizations were employed at 2-week interval for 3 times. ELISA assay was used for the quantitative detection of the specific antibody in the sera of rabbits, and the proliferation response of spleen cells was detected by MTT assay. It was found that the target gene Tp92 segment about 2103 bp was obtained, and the DNA sequence of Tp92 gene constructed in pcDNA3.1 (+) vector was consistent with the published nucleotide sequence. The homologies of the nucleotide and putative amino acid sequences of Tp92 gene between T.pallidum subsp. pallidum Nichols and various pathogenic treponeme strains were 95.5%-100%. The analysis of immunocytochemistry and Western blotting showed that Tp92 gene segment constructed in pcDNA3.1(+) vector could express a fusion protein with a calculated molecular mass of 77 kDa in HeLa cells and the expressed protein could react with positive blood serum from syphilis patient. The specific antibody IgG titers were observed and the highest titer was 1∶1024 in rabbits after 3 times with pcDNA3.1(+)-Tp92. The proliferation response of spleen cells were significantly higher than that of rabbits injected with pcDNA3.1(+) ( P <0.05). The successful expression of the eukaryotic expression plasmid of Tp92 gene from T. pallidum was obtained in eukaryotic system and strong responses of humoral and cellular immunity was evoked by DNA vaccine of pcDNA3.1(+)-Tp92 in rabbits thus establishing a solid basis for the future studies in the biological activities and for the development of the syphilis DNA vaccine.
文摘Osteosarcoma is a rare and highly malignant tumor that usually affects adolescents and young adults. Despite current management protocols, up to half of patients succumb to the disease. Moreover, there is no well-characterized molecular marker for diagnosis and prognosis. TP53 alterations have been associated with a poor prognosis in many cancers. The aim of this retrospective work was to find out whether TP53 functional status predicts response to neoadjuvant chemotherapy and thus may help treatment decision for osteosarcoma patients. Seventeen biopsies of osteosarcoma patients receiving primary metotrexate, cisplatin and adryamicin chemotherapy followed by surgery were analyzed. TP53 exons 5-9 mutations were screened. Among 17 biopsies, 4 (23.5%) displayed TP53 mutations: 3 deletions and one single-nucleotide substitution. The presence of TP53 gene mutation does not correlate with resistance to chemotherapy according to histological Rosen grade and nevertheless is associated with patient’s age in a significant manner (p 0.05). The presence of non-mutated TP53 is not entirely specific for a good prognosis. We found no evidence that TP53 mutations predict chemoresistance in osteosarcoma patients more over the overall survival curve, followed for more than 12 years, showing no difference between patients with tumors harboring wild type or mutated TP53 gene (p 0.5). Further analysis to identify other genes that can influence chemotherapy response and clinical outcome in osteosarcoma is needed to improve patient treatment.
