低剂量亚砷酸及维甲酸方案对儿童骨髓增生异常综合征p15INK4B基因的影响

目的 探讨低剂量亚砷酸及维甲酸双诱导方案对骨髓增生异常综合征(MDS)患儿p15INK44B基因表达的影响及患儿p15INK4B基因甲基化水平的变化.方法 11例MDS患儿接受低剂量亚砷酸及维甲酸双诱导方案治疗,应用实时荧光定量聚合酶链反应(PCR)方法检测治疗前后p15INK4B基因的表达,应用亚硫酸氢钠修饰及实时荧光定量PCR方法检测p15INK4B基因的甲基化水平.结果 11例MDS患儿经过双诱导方案治疗后,9例获益.治疗后10例患儿p15INK4B基因表达水平显著升高,治疗前后p15INK4B基因甲基化水平分别为(1.68±0.58)％、(1.44±0.65)％,二者差异无统计学意义(t=-0.885,P＞0.05).结论 低剂量亚砷酸及维甲酸双诱导方案治疗儿童MDS疗效较好,该方案的作用机制可能与p15INK4B基因表达升高有关,但p15INK4B基因表达升高与去甲基化无相关性.     

DNA甲基化与骨髓增生异常综合征研究进展

随着肿瘤表观遗传学的深入研究,DNA甲基化异常在血液肿瘤的发生和转化中起着重要作用。近来研究显示p15基因、降钙素基因、紧密连接蛋白-1基因等高度甲基化与骨髓增生异常综合征的发生发展具有重要关系。5-氮杂胞苷和5-2′-脱氧胞嘧啶等在骨髓增生异常综合征患者的治疗中已经取得一定效果。去甲基化治疗有望成为骨髓增生异常综合征治疗的有效方案之一。     

骨髓增生异常综合征患者Dickkopf-3基因启动子区甲基化状态研究

目的 了解骨髓增生异常综合征(MDS)患者WNT/β-catenin信号转导通路中拮抗基因Dickkopf-3(Dkk3)的甲基化状态,初步探索其甲基化状态与MDS发生及疾病进展的关系.方法 应用甲基化特异性PCR(MSP)法对43例MDS患者的骨髓或外周血Dkk3基因启动子区甲基化状况进行检测,并以70例门诊普通患者的外周血检测结果作为对照,同时对患者进行随访.结果 43例MDS患者中检出7例(16.3％)Dkk3甲基化,其中5例(11.6％)为半甲基化状态,2例(4.7％)为完全甲基化状态,70例正常对照中1例(1.4％)为Dkk3甲基化,组间DKK3甲基化率差异有统计学意义(x2=8.93,P=0.005).7例Dkk3甲基化的样本中,2例来自骨髓,5例来自外周血,其中难治性贫血(RA)2例,难治性细胞减少伴多系异常(RCMD)1例,难治性贫血伴原始细胞增多(RAEB)4例.单因素分析示不同性别、染色体核型、样本来源(骨髓/外周血)、危险度(WHO分类的预后评分系统≤2分及＞2分)及老年组与非老年组间甲基化率差异均无统计学意义(均P＞0.05).在35例长期随访患者中,9例患者转化为急性髓系白血病(AML)(6例DKK3甲基化者中3例,29例DKK3非甲基化者中6例),疾病进展组与稳定组间甲基化率差异无统计学意义(P＞0.05);死亡12例中3例为Dkk3甲基化阳性,但甲基化与非甲基化组间生存率差异无统计学意义(P＞0.05).结论 MDS患者中Dkk3基因存在较高的甲基化修饰,这可能是MDS发病的分子机制之一.本组患者例数较少,尚未发现甲基化与临床预后间的相关性.     

骨髓增生异常综合征DNA甲基化及其治疗机制的进展

骨髓增生异常综合征（myelodysp lasticsyndrome,MDS）仍为血液病学较难攻克的一大主题。近年由于DNA甲基化研究的进展及DNA去甲基化药物的开发、使用,为MDS的治疗提供了更多可能的靶点。全文就近年DNA甲基化及去甲基化治疗相关机制的研究进展作一介绍。     

骨髓增生异常综合征患者分泌型卷曲相关蛋白2基因启动子区甲基化状态研究

 目的　了解骨髓增生异常综合征（MDS）患者Wnt／β-catenin信号转导通路中拮抗基因分泌型卷曲相关蛋白2（SFRP2）的甲基化状态,研究其甲基化状态与染色体核型及生存的关系。方法　应用甲基化特异性聚合酶链反应（MSP）对43例MDS患者的骨髓或外周血SFRP2基因启动子区甲基化状况进行检测,并以70例门诊普通患者外周血检测结果为对照,同时对部分患者进行随访。结果　43例MDS患者中检出10例（23.3 %）SFRP2甲基化,均为半甲基化状态,70例正常对照中未检出SFRP2的甲基化,组间差异有统计学意义（χ2＝17.86,P＜0.0001）。10例SFRP2甲基化的样本中, 5例来自骨髓,5例来自外周血,其中难治性贫血（RA）3例,伴环形铁粒幼细胞增多性难治性贫血（RAS）1例,难治性血细胞减少伴多系发育异常（RCMD）2例,原始细胞过多难治性贫血（RAEB）3例,MDS不能分类（MDS-U）1例。单因素分析结果显示不同性别、年龄、染色体核型、样本来源（骨髓／外周血）、危险度（WPSS≤2及>2）间甲基化率差异无统计学意义,疾病进展与稳定组甲基化率差异亦无统计学意义（均P＞0.05）。20例患者有染色体核型结果,16例进行了密切随访,3例转为急性髓系白血病（AML）,死亡11例中2例为SFRP2甲基化阳性,但甲基化与非甲基化组间生存率差异无统计学意义（χ2＝0.022,P＞0.05）。结论　MDS患者中SFRP2基因存在较高的甲基化修饰,这可能是MDS发病的分子机制之一;在MDS SFRP2的甲基化检测中,外周血有较好的代表性;该组患者例数较少,尚未发现甲基化与临床预后间的相关性。     

骨髓增生异常综合征的治疗进展

骨髓增生异常综合征是一组造血干细胞克隆性疾病,因病态造血导致进行性、难治性血细胞减少为特征,临床主要表现为贫血、感染和出血。少数有进展为急性白血病的危险。目前仍缺乏有效的根治疗法,本文重点讨论MDS的现有治疗和相关的支持治疗。     

骨髓增生异常综合征的治疗进展

骨髓增生异常综合征是一组造血干细胞克隆性疾病,因病态造血导致进行性、难治性血细胞减少为特征,临床主要表现为贫血、感染和出血。少数有进展为急性白血病的危险。目前仍缺乏有效的根治疗法,本文重点讨论MDS的现有治疗和相关的支持治疗。     

骨髓增生异常综合征患者低甲基化治疗失败后的治疗选择

骨髓增生异常综合征(MDS)的主要治疗包括支持治疗(如输血、集落刺激因子、螯合铁等)和靶向药物(5-氮杂胞苷、地西他滨、来那度胺).如果患者对以上药物无效,则缺乏有效的治疗方法.治疗失败后,目前努力的方向是继续调整并优化去甲基化药物(HMT)方案,改善药物制剂[口服制剂和(或)新制剂],根据突变筛选患者,提高HMT治疗MDS的针对性和有效性.此外,正在进行的研究重点是确定用来作为HMT治疗失败后挽救MDS患者的独特药物.如rigosertib最有可能使特定人群[原发性难治性和国际预后评分系统(IPSS)评分为高危的患者]受益.鉴于实体肿瘤免疫逃逸的重要进展,程序性死亡受体1(PD-1)和PD-1抑制剂单剂可在早期治疗和复发时联合HMT治疗MDS.对于那些有特定靶向突变基因的少数民族患者,有替代药物(IDH1/2)是非常有希望的.骨髓移植是治愈MDS的唯一方法,但因MDS进展时大多患者都年老体弱,所以移植的可行性不大.     

低增生性骨髓增生异常综合征治疗的进展

 低增生性骨髓增生异常综合征（Hypo-MDS）骨髓结构紊乱，病态巨核细胞增生明显，以骨髓低细胞容积和病态造血为共同特征，目前尚无统一的治疗标准，对其治疗应该引起注意。文章对Hypo-MDS治疗的研究进展进行了综述。     

慢性乙型肝炎病毒感染与p16INK4A基因启动子甲基化关系的研究

目的探讨慢性乙型肝炎病毒(HBV)感染对p16INK4A基因启动子甲基化的影响及其在HBV相关肝细胞癌(HCC)形成中的作用。方法选取23例HBV相关HCC癌及癌旁组织、25例慢性乙型肝炎肝穿刺组织,采用甲基化特异性PCR(MSP)检测p16INK4A基因启动子的甲基化状态;免疫组化EnVision二步法测定肝组织内HBsAg、HBcAg、HBeAg和HBx蛋白的表达;荧光实时定量PCR检测肝组织HBV DNA含量;PCR扩增和直接测序检测HBV x基因变异。结果癌组织p16INK4A基因启动子甲基化阳性率(47.83%)明显高于癌旁组织(17.39%),慢性乙型肝炎患者p16INK4A基因启动子甲基化阳性率(36.00%)与癌组织、癌旁组织差异无统计学意义。在癌旁组织和慢性乙型肝炎, p16INK4A基因启动子甲基化者HBx蛋白表达中位数分别为3.000和0.250,明显高于非甲基化者(0.500和0.000),但在癌组织中,HBx蛋白的表达与p16INK4A基因启动子甲基化状态无关。HBsAg、HBcAg、组织HBV DNA含量和x基因突变均与p16INK4A基因启动子甲基化状态无关。结论在癌前病变中,p16INK4A基因启动子甲基化与HBx蛋白高表达有关,HBx蛋白可能通过诱导p16INK4A基因启动子甲基化而使该抑癌基因失活,在HBV相关HCC形成中起重要作用。     

Role of p15(INK4B) Methylation in Patients With Myelodysplastic Syndromes: A Systematic Meta-Analysis

BackgroundTumor suppressor gene cyclin-dependent kinase inhibitor 2B (p15(INK4B)) methylation has been frequently reported in myelodysplastic syndromes (MDS). However, the association between p15(INK4B) methylation and MDS remains elusive. Thus, this meta-analysis was first conducted to evaluate the clinical significance of p15(INK4B) methylation in MDS.Materials and MethodsEligible studies were identified via an online electronic databases search. The overall odds ratios (ORs) or hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated.ResultsTwenty-eight studies published between 1997 and 2017 were identified, including 1205 MDS patients and 243 nontumor controls. No evidence of heterogeneity was found in our study. p15(INK4B) methylation was significantly elevated in MDS compared with nontumor controls (OR, 10.37; P < .001). In addition, p15(INK4B) methylation was significantly higher in advanced MDS than in early MDS (OR, 4.70; P < .001) and was linked to an unfavorable overall survival (multivariate analysis: HR, 1.78; 95% CI, 1.23-2.71). Subgroup analyses on the basis of ethnicity and detection method showed that the results remained significant in different subgroups (all Ps < .05).ConclusionOur findings suggest that p15(INK4B) methylation might play an important role in the development, progression, and poor prognosis of MDS. More prospective studies with larger study populations are needed.     

p15INK4B基因转染联合TGF-β1对人食管鳞癌的抑制作用

目的：探讨p15^INK4B基因转染与TGF-β1联合应用对人食管鳞癌细胞系EC109细胞增殖和凋亡的影响。方法：脂质体介导将pCDNA3．1（＋）-p15转染EC109细胞，稳定筛选后加入10ng／ml的TGF-β1。PCR检测外源P15基因，Western blot检测转染细胞P15蛋白的变化。用MTT、集落形成实验、流式细胞仪和透射电镜检测p15转染TGF-β1对EC109增殖和凋亡的影响。结果：联合应用与二者单独应用相比。明显抑制EC109生长速度．集落形成率显著降低（P〈0．01）。发生G1／S阻滞。G1期比例显著升高（P〈0．05），S期比例明显降低（P〈0．05）。凋亡率明显升高（P〈0．01）。透射电镜发现二者联合应用诱导EC109发生明显的细胞凋亡。结论：p15基因转染与TGF-β1联合应用可以进一步增强对食管鳞癌EC109细胞的抑制作用并诱导其凋亡。     

p14ARF, p15INK4b and p16INK4a methylation status in chronic myelogenous leukemia

The INK4 family of proteins p15^INK4b, p14^ARF and p16^INK4a function as cell cycle inhibitors where they are involved in the inhibition of G1 phase progression. Methylation of the p15^INK4b promoter never seems to occur in solid tumors but is a major gene silencing mechanism in hematological malignancies. p14^ARF and p16^INK4a promoter methylation often occurs in solid tumors but also in leukemias and lymphomas. In chronic myelogenous leukemia (CML), only a few reports have been published regarding INK4 methylation and the results of the literature are discordant. Thus clearly, more works on large series have to be performed independently.     

Lack of Increased P15INK4B Protein Expression in Basal Cell Carcinomas

Background: The basal cell carcinoma (BCC) is the most common non-melanoma skin cancer (NMSK). BCCmight develop because of the faulty cell cycle arrest. P15INK4b is a tumor suppressor gene, involved in cell cyclearrest and inactivated in most human cancers. The role of p15INK4b protein expression in the genesis of BCC is asyet unknown. In a previous study we showed the absence of p15INK4b expression in the majority of tissue microarraycores of cutaneous squamous cell carcinoma (SCCs), another type of non-melanoma skin cancer, indicating thatp15INK4b could possibly be involved in the pathogenesis of cutaneous SCC. The aim of this study was to investigatep15INK4b protein expression in BCCs. Materials and Method: Protein expression of p15INK4b in 35 cases of BCCtissue arrays and 19 cases of normal human skin tissue was studied using an immunohistochemical approach.Results: The expression of p15INK4b was not significantly different in the BCC cases as compared with normalhuman skin (p=0.356; p>0.05). In addition, there were no significant relationship between clinicopathologicvariables of patients (age and sex) and p15INK4b protein expression. Conclusions: Our finding may indicate thatp15INK4b protein expression does not play a role in the genesis of BCC.     

Loss of p15INK4b Expression in Colorectal Cancer is Linked to Ethnic Origin

Colorectal cancers remain to be a common cause of cancer-related death. Early-onset cases as well as those ofvarious ethnic origins have aggressive clinical features, the basis of which requires further exploration. The aimof this work was to examine the expression patterns of p15INK4b and SMAD4 in colorectal carcinoma of differentethnic origins. Fifty-five sporadic colorectal carcinoma of Egyptian origin, 25 of which were early onset, and54 cancers of Finnish origin were immunohistochemically stained with antibodies against p15INK4b and SMAD4proteins. Data were compared to the methylation status of the p15INK4b gene promotor. p15INK4b was totally lostor deficient (lost in ≥50% of tumor cell) in 47/55 (85%) tumors of Egyptian origin as compared to 6/50 (12%)tumors of Finnish origin (p=7e-15). In the Egyptian cases with p15INK4b loss and available p15INK4b promotormethylation status, 89% of cases which lost p15INK4b expression were associated with p15INK4b gene promotorhypermethylation. SMAD4 was lost or deficient in 25/54 (46%) tumors of Egyptian origin and 28/48 (58%)tumors of Finnish origin. 22/54 (41%) Egyptian tumors showed combined loss/deficiency of both p15INK4b andSMAD4, while p15INK4b was selectively lost/deficient with positive SMAD4 expression in 24/54 (44%) tumors.Loss of p15INK4b was associated with older age at presentation (>50 years) in the Egyptian tumors (p=0.04). Thesedata show for the first time that p15INK4b loss of expression marks a subset of colorectal cancers and ethnic originmay play a role in this selection. In a substantial number of cases, the loss was independent of SMAD4 butrather associated with p15INK4b gene promotor hypermethylation and old age which could be related to differentenvironmental exposures.     

宫颈液基细胞学标本中p16^INK4A的表达

[目的]探讨p16^INK4A在新柏氏宫颈液基细胞学（TCT）标本中各级宫颈上皮内瘤变的表达，评价其在宫颈病变中表达的意义。[方法]采用Envision法，检测76例TCT标本及相应宫颈活检组织中p16^INK4A表达。[结果]在TCT中，P16^INK4A在无上皮内病变（NILM）、非典型鳞状细胞（ASC）、低级别鳞状上皮内病变（LSIL）、高级别鳞状上皮内病变（HSIL）阳性表达率分别为0、15．78％、45．45％、88％。在相应活检组织中，p16^INK4A在宫颈炎、CINI、CINⅡ、CINⅢ中阳性表达率分别为0、63．15％、89．28％、100％。p160^INK4A在TCT和相应活检组织中表达的符合率为91.23％。[结论]TCT标本的p16^INK4A表达检测可以提高宫颈高级别病变的检出率。     

Inactivation of the p15INK4B and p16INK4 Genes in Hematologic Malignancies

The recently discovered p15^INK4B and p16^INK4 genes encoding cell cycle regulating proteins, map to a region on chromosome 9p21 that is commonly deleted in a variety of malignant diseases. The p16^INK4 gene has now been shown to be a tumor suppressor gene. It is frequently inactivated in cancer and is possibly the second most often mutated gene in human malignant disease after p53. The role of the p15^INK4B and p16^INK4 genes in hematologic malignancies has been the subject of intense investigation since their discovery. In this review we address the function and possible role in tumorigenesis of the p15^INK4B and p16^INK4 genes and discuss their significance as prognostic markers in hematologic malignancies.     

p16INK4a在宫颈液基细胞学辅助筛查中的标记意义

目的 评价p16INK4a在宫颈液基细胞学检查中的标记意义.方法 收集74例宫颈外口和颈管的脱落细胞标本,分别进行液基细胞学检测和p16INK4a免疫细胞化学染色,并应用杂交捕获二代法检测高危人乳头瘤病毒(HR-HPV)感染.结果 74例标本中,细胞学诊断未见癌细胞或癌前病变细胞(阴性)10例,意义不明的不典型鳞状细胞(ASC-US)15例,鳞状上皮内低度病变(LSIL)28例,不除外上皮内高度病变的不典型鳞状细胞(ASC-H)5例,鳞状上皮内高度病变(HSIL)11例,鳞状细胞癌(SCC)5例.各级别病变中,HR-HPV阳性者分别为1、4、3、9、7和5例,p16INK4a免疫细胞化学染色阳性者分别为2、5、3、8、9和5例.随着宫颈病变级别的上升,HR-HPV和p16INK4a免疫细胞化学染色阳性率均增高.结论 p16INK4a免疫细胞化学染色增强了对不典型细胞的区分能力,可以提高宫颈癌筛查的准确性.