Clinical significance of autoantibodies to p53 protein in patients with autoimmune liver diseases

BACKGROUND:Autoantibodies to p53 (anti-p53) are rarely present in the sera of patients with autoimmune diseases or the sera of patients with malignancies.OBJECTIVE:To examine the prevalence of anti-p53 in patients with autoimmune liver disease including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), AIH/PBC overlap syndrome (AIH/PBC OS) and primary sclerosing cholangitis (PSC), and to determine the clinical significance of anti-p53 in autoimmune liver diseases.METHODS:Forty patients with AIH, 41 patients with PBC, eight patients with AIH/PBC OS and five patients with PSC were enrolled. Anti-p53 and antibodies to double-stranded DNA (anti-ds-DNA) were analyzed using commercially available ELISA kits. Demographic, laboratory and histological data were compared between the AIH groups seropositive and seronegative for anti-p53.RESULTS:Six of 40 (15.0%) patients with AIH and four of eight (50.0%) patients with AIH/PBC OS were positive for anti-p53. One of 41 (2.4%) patients with PBC was also positive for anti-p53, but all five patients with PSC were negative, indicating a significantly higher prevalence of anti-p53 in patients with AIH or AIH/PBC OS compared with patients with PBC. None of the AIH patients positive for anti-p53 progressed to hepatic failure or relapsed after immunosuppressive treatment. Titres of anti-ds-DNA in patients with AIH and AIH/PBC OS significantly correlated with titres of anti-p53 (r=0.511; P=0.0213).CONCLUSION:The emergence of anti-p53 is likely to be useful for discriminating AIH or AIH/PBC OS from PBC and helpful for predicting favourable prognoses in patients with AIH. DNA damage may trigger the production of anti-p53 in patients with AIH or AIH/PBC OS.     

The combination of bortezomib and dexamethasone is an efficient therapy for relapsed/refractory scleromyxedema: a rare disease with new clinical insights

Scleromyxedema (SM) is a rare primary cutaneous inflammatory mucinosis characterised by papular mucinosis, monoclonal gammopathy and extracutaneous involvement. Most therapeutic options have failed in SM but high-dose therapy followed by autologous peripheral blood stem cell transplantation (APBSCT) appears to be highly effective, although SM normally relapses. We report the case of a 29-yr-old patient with severe SM who achieved stringent complete response with Bortezomib plus Dexamethasone after an early relapse subsequent to a high-dose melphalan regimen followed APBSCT. It is of particular note that dermatological lesions responded to both therapies before M-component modifications, suggesting that SM is independent of M-component characteristics. However, treatment should be directed towards the underlying plasma cell malignancy with typical anti-myeloma agents.     

下呼吸道感染患者铜绿假单胞菌分离株氨基糖苷类耐药相关基因分析

目的探讨分离自下呼吸道感染患者的氨基糖苷类耐药铜绿假单胞菌的耐药机制。方法从下呼吸道感染患者痰液中分离出52株对氨基糖苷类耐药的铜绿假单胞菌,PCR法检测6种氨基糖苷类修饰酶(AMEs)基因,并检测其中泛耐药菌的6种16S rRNA甲基化酶基因(以下简称甲基化酶基因)。对阳性产物测序加以证实。结果 52株铜绿假单胞菌中检出4种AMEs基因[aac(3)-Ⅱ、aac(6’)-Ⅰb、aac(6’)-Ⅱ和ant(2″)-Ⅰ],AMEs基因总检出率为92.3%。泛耐药菌中检出1种甲基化酶基因(rmtB)。16株高水平泛耐药菌中rmtB基因的检出率为81.3%。结论分离自下呼吸道感染患者的氨基糖苷类耐药铜绿假单胞菌中AMEs基因携带率高,其对氨基糖苷类耐药与aac(3)-Ⅱ、aac(6’)-Ⅰb、aac(6’)-Ⅱ和ant(2″)-Ⅰ有关;对氨基糖苷类高水平泛耐药主要与甲基化酶基因rmtB有关。     

p53、PTEN和VEGF在胃癌组织中的表达及意义

目的探讨p53、PTEN、VEGF表达在胃癌发生、发展中的作用及其相关影响因素。方法采用免疫组织化学法检测80份胃癌组织中p53、PTEN、VEGF表达,并分析其与胃癌临床病理特征的关系。结果 p53、PTEN、VEGF在胃癌组织中的阳性表达率依次为55%(44/80)、92.5%(74/80)、52.5%(42/80);胃癌组织中p53、VEGF表达阳性率明显高于对照组,P<0.01。三者表达与性别、年龄、肿瘤分化程度、浸润情况、淋巴结转移等均无明显相关性;任意两个指标之间相关性亦不显著。结论 p53、VEGF对胃癌的诊断有一定价值;p53、VEGF、PTEN对胃癌肿瘤分化、浸润和转移等的诊断价值不大,各指标间的相关性不显著。     

塞来昔布联合p65miRNA抑制人乳腺癌移植瘤的生长

目的探讨下调核因子NF-κB p65亚基的表达联合塞来昔布对人乳腺癌裸鼠移植瘤生长的协同抑制效应及其机制。方法建立人乳腺癌裸鼠移植瘤模型,随机将裸鼠分为6组,control组、Neg-miRNA组、p65miRNA组、塞来昔布组、塞来昔布+Neg-miRNA组、塞来昔布+p65miRNA组。观察治疗前后裸鼠的一般状态、肿瘤体积和瘤重,计算平均抑瘤率。免疫组化法检测p65miRNA干扰后肿瘤组织中p65蛋白的表达。RT-PCR、Western印迹法检测肿瘤组织中血管内皮生长因子(VEGF)、金属基质蛋白酶(MMP-2)基因mRNA及蛋白表达的变化。结果塞来昔布组、p65miRNA组和塞来昔布+p65miRNA组肿瘤生长受到明显抑制,抑瘤率分别为43.23%、40.72%及61.69%。p65miRNA组较对照组p65蛋白表达明显减少。塞来昔布组、p65miRNA组和塞来昔布+p65miRNA组VEGF、MMP-2 mRNA及蛋白表达受到不同程度地抑制。结论塞来昔布及p65miRNA均具有明显的抗肿瘤作用,联合应用时具有一定的协同作用,可显著抑制人乳腺癌裸鼠移植瘤的生长,并可显著下调VEGF、MMP-2的表达。     

MLPA技术在检测胰腺癌细胞系9p21大片段缺失中的应用

目的:评价MLPA技术检测染色体9p21区大片段缺失的有效性及判断缺失边界的准确性,并探讨染色体9p21区大片段缺失的意义.方法:利用MLPA技术检测胰腺癌细胞系PANC-1和BxPC3的9p21区缺失情况,并利用常规PCR实验对MLPA缺失边界进行验证.结果:MLPA检测发现PANC-1和BxPC3均存在累及MTAP、CDKN2A和CDKN2B等基因大片段缺失的情况.PCR实验证实MLPA对PANC-1端粒侧的缺失边界判断准确.PANC-1细胞系染色体9p21区大片段缺失的端粒侧缺失断点位于MTAP基因内.结论:MLPA技术是检测染色体9p21大片段缺失的有效方法,能准确判断大片段缺失边界范围,适合于aCGH检测后大样本筛查.PANC-1细胞系中染色体9p21区大片段缺失可能改变MTAP基因结构.     

p53异构体Δ133p53在不同胃组织中的表达及意义

目的探讨p53选择性剪接异构体Δ133p53的mRNA在胃癌、慢性萎缩性胃炎和慢性浅表性胃炎组织中的表达及意义。方法采用巢式逆转录多聚酶链反应检测Δ133p53在30例胃癌、30例慢性萎缩性胃炎和20例慢性浅表性胃炎组织中的表达。结果Δ133p53在胃癌、慢性萎缩性胃炎和慢性浅表性胃炎组织中的阳性表达率分别为70.0%、50.0%和25.0%,差异有统计学意义(P均<0.05)。结论①Δ133p53的表达在胃癌、慢性萎缩性胃炎和慢性浅表性胃炎组织中呈逐渐明显下降趋势。②Δ133p53异构体可能对胃癌的发生发展及其诊断、治疗具有重要作用。     

p53异构体和MDM2、PTEN在胃癌组织中表达的相关性

目的探讨p53的选择性剪接异构体与双微基因2(MDM2)、同源性磷酸酶张力蛋白(PTEN)在胃癌组织中的表达及其相关性。方法分别应用巢式逆转录多聚酶链反应(NT-PCR)和免疫组织化学(PV-9000两步法)方法检测p53的五种选择性剪接异构体和MDM2、PTEN在胃癌组织和癌旁胃组织中的表达,并进行统计学分析。结果在30例胃癌患者癌组织和癌旁胃组织中均未检测到三种p53异构体p53γ、Δ133p53β、Δ133p53γ的mRNA表达。与癌旁组织比较,胃癌组织中Δ133p53表达阳性率高,p53β表达阳性率低,MDM2蛋白表达阳性率高,PTEN蛋白表达阳性率低(P均<0.01)。Spearman’s相关性分析显示,Δ133p53和MDM2,p53β和PTEN在胃癌中表达均呈正相关关系(r=0.408,P=0.025;r=0.413,P=0.02);Δ133p53和PTEN,p53β和MDM2在胃癌中表达呈负相关关系(r=-0.467,P=0.009;r=-0.480,P=0.007)。结论Δ133p53、p53β通过调节p53活性,并以p53为中介,影响了PTEN-MDM2-p53网络环路中PTEN、MDM2蛋白的表达。     

大鼠重症急性胰腺炎发病机制中p38丝裂原活化蛋白激酶的作用研究

目的探讨p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)特异性抑制剂SB203580对大鼠重症急性胰腺炎(SAP)的保护作用。方法以胆胰管逆行注射5%牛磺胆酸钠建立SD大鼠SAP模型。将45只SD大鼠随机分为3组,假手术组(SO组,n=15);SAP组(SAP组,n=15);SB203580治疗组(SB组,n=15)。术后3、6、12 h处死大鼠并取血。对胰腺进行病理组织学评分,测定大鼠腹水量。检测血清淀粉酶,ELISA法测定血清IL-6和IL-10水平。并采用免疫组化法观察大鼠胰腺组织p38 MAPK下游靶点P-ATF2表达情况。结果 SO组胰腺组织存在P-ATF2弱表达,SAP组各时间点P-ATF2表达水平明显升高(P<0.01),SB组各时间点表达水平较SAP组下降明显(P<0.01)。SAP组6、12 h时间点IL-6水平,3、6 h时间点IL-10水平,血清淀粉酶,腹水量明显高于SB组(P<0.05)。SAP组各时间点胰腺组织病理学积分显著高于SB组,差异有统计学意义(P<0.05)。结论阻断p38 MAPK信号传导通路可以明显缓解大鼠重症急性胰腺炎的病情。预示此信号传导通路可以为SAP的治疗提供一个有价值的标靶。     

Germline promoter hypermethylation of tumor suppressor genes in gastric cancer

AIM: To explore germline hypermethylation of the tumor suppressor genes MLH1, CDH1 and P16^INK4a in suspected cases of hereditary gastric cancer (GC).METHODS: A group of 140 Chinese GC patients in whom the primary cancer had developed before the age of 60 or who had a familial history of cancer were screened for germline hypermethylation of the MLH1, CDH1 and P16^INK4a tumor suppressor genes. Genomic DNA was extracted from peripheral blood leukocytes and modified by sodium bisulfite. The treated DNA was then subjected to bisulfite DNA sequencing for a specific region of the MLH1 promoter. The methylation status of CDH1 or P16^INK4a was assayed using methylation-specific PCR. Clonal bisulfite allelic sequencing in positive samples was performed to obtain a comprehensive analysis of the CpG island methylation status of these promoter regions.RESULTS: Methylation of the MLH1 gene promoter was detected in the peripheral blood DNA of only 1/140 (0.7%) of the GC patient group. However, this methylation pattern was mosaic rather than the allelic pattern which has previously been reported for MLH1 in hereditary non-polyposis colorectal cancer (HNPCC) patients. We found that 10% of the MLH1 alleles in the peripheral blood DNA of this patient were methylated, consistent with 20% of cells having one methylated allele. No germline promoter methylation of the CDH1 or P16^INK4a genes was detected.CONCLUSION: Mosaic germline epimutation of the MLH1 gene is present in suspected hereditary GC patients in China but at a very low level. Germline epimutation of the CDH1 or P16^INK4a gene is not a frequent event.