老年胶质母细胞瘤患者MGMT甲基化状态对放化疗及预后影响

目的:探讨O-6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)基因启动子甲基化状态对老年胶质母细胞瘤(GBM)治疗及预后的影响。方法:回顾性分析天津市环湖医院2012—2018年收治的65例新诊断的老年GBM患者的临床资料。所有患者均在术后接受了调强放疗,49例患者接受了替莫唑胺单药化疗。依据MGMT启动子甲基化状态分为M...     

Clinical correlation of MGMT protein expression and promoter methylation in Chinese glioblastoma patients

Promoter methylation of O6-methylguanine-DNA methyltransferase (MGMT) gene has been considered as a prognostic maker and increasingly emphasized in the treatment of glioblastoma multiforme (GBM). Contrastingly, the correlation of MGMT with clinical outcomes in Chinese glioblastoma patients has not been elucidated systematically. In the present study, tumor tissues from 172 GBM patients were analyzed for MGMT protein expression by immunohistochemistry. Of these, 79 were also subjected to pyrosequencing for MGMT promoter methylation analysis. MGMT protein overexpression was found in 109/172 (63.4%) GBM samples. And no significant survival difference was observed between the patients with MGMT overexpression and low expression in terms of progression-free survival or overall survival (P = 0.605 and P = 0.565, respectively). Meanwhile, MGMT promoter methylation was detected in 26/79 cases (32.9%), whereas 53/79 (67.1%) samples were unmethylated. Further survival analysis also revealed that MGMT promoter methylation status cannot predict patients progression-free survival and overall survival (P = 0.906 and P = 0.548, respectively). The integrated analysis showed that there was significant negative correlation between MGMT protein expression and promoter methylation (P = 0.004). These results underscore that, in Chinese GBM patients, (a) MGMT protein expression level was not a prognostic factor, (b) overall survival but not progression-free survival showed a trend toward increase in patients with MGMT promoter methylation, although the difference was not significant statistically and this observation has to be validated in larger patients cohort, (c) there was a significant correlation between MGMT protein expression in immunohistochemistry and MGMT promoter methylation by pyrosequencing.     

Methylation of O6-methylguanine DNA methyltransferase and loss of heterozygosity on 19q and/or 17p are overlapping features of secondary glioblastomas with prolonged survival.

PURPOSE: Recent data suggest that methylation of the DNA repair gene O(6)-methylguanine DNA methyltransferase (MGMT), by increasing the chemosensitivity of glioblastoma multiforme, is significantly associated with improved prognosis. Results in contradiction with these findings, however, are present in the literature and the clinical and genetic context framing MGMT methylation is poorly characterized. EXPERIMENTAL DESIGN: To address these issues, we have investigated the MGMT methylation status, clinical and magnetic resonance imaging characteristics, and relevant genetic features (loss of heterozygosity on 17p and 19q, EGFR amplification, and p53 mutations) in a retrospective study on 86 patients affected by glioblastoma multiforme: 72 patients had a clinical history indicating de novo insurgence of the tumor and the remaining 14 were secondary glioblastoma multiforme. RESULTS: MGMT methylation was detected by methylation-specific PCR in 41 of 86 cases (47.7%; Meth+). Progression-free survival and overall survival were significantly longer in Meth+ than in Meth- patients [10 versus 7 months (P=0.003, log-rank test) and 18 versus 14 months (P=0.0003, log-rank test), respectively]. Mixed-nodular enhancement at magnetic resonance imaging was significantly more frequent in Meth+ and secondary glioblastoma multiforme and ring enhancement in Meth- and primary glioblastoma multiforme (P<0.005). MGMT methylation was more present in secondary glioblastoma multiforme (P=0.006) and associated with loss of heterozygosity on 17p and/or 19q (P=0.005). CONCLUSIONS: These observations suggest that MGMT methylation is part of a genetic signature of glioblastomas that developed from lower-grade gliomas.     

Association of miR-193b Down-regulation and miR-196a up-Regulation with Clinicopathological Features and Prognosis in Gastric Cancer

Dysregulated expression of microRNAs (miRNAs) has been shown to be closely associated with tumordevelopment, progression, and carcinogenesis. However, their clinical implications for gastric cancer remainelusive. To investigate the hypothesis that genome-wide alternations of miRNAs differentiate gastric cancer tissuesfrom those matched adjacent non-tumor tissues (ANTTs), miRNA arrays were employed to examine miRNAexpression profiles for the 5-pair discovery stage, and the quantitative real-time polymerase chain reaction (qRTPCR)was applied to validate candidate miRNAs for 48-pair validation stage. Furthermore, the relationshipbetween altered miRNA and clinicopathological features and prognosis of gastric cancer was explored. Amonga total of 1,146 miRNAs analyzed, 16 miRNAs were found to be significantly different expressed in tissues fromgastric cancer compared to ANTTs (p<0.05). qRT-PCR further confirmed the variation in expression of miR-193band miR-196a in the validation stage. Down-expression of miR-193b was significantly correlated with Laurentype, differentiation, UICC stage, invasion, and metastasis of gastric cancer (p<0.05), while over-expression ofmiR-196a was significantly associated with poor differentiation (p=0.022). Moreover, binary logistic regressionanalysis demonstrated that the UICC stage was a significant risk factor for down-expression of miR-193b (adjustedOR=8.69; 95%CI=1.06-56.91; p=0.043). Additionally, Kaplan-Meier survival curves indicated that patientswith a high fold-change of down-regulated miR-193b had a significantly shorter survival time (n=19; mediansurvival=29 months) compared to patients with a low fold-change of down-regulated miR-193b (n=29; mediansurvival=54 months) (p=0.001). Overall survival time of patients with a low fold-change of up-regulated miR-196a (n=27; median survival=52 months) was significantly longer than that of patients with a high fold-changeof up-regulated miR-196a (n=21; median survival=46 months) (p=0.003). Hence, miR-193b and miR-196a maybe applied as novel and promising prognostic markers in gastric cancer.     

O6-Methylguanine DNA methyltransferase protein expression in tumor cells predicts outcome of temozolomide therapy in glioblastoma patients

O⁶-Methylguanine DNA methyltransferase (MGMT) is implicated as a major predictive factor for treatment response to alkylating agents including temozolomide (TMZ) of glioblastoma multiforme (GBM) patients. However, whether the MGMT status in GBM patients should be detected at the level of promoter methylation or protein expression is still a matter of debate. Here, we compared promoter methylation (by methylation-specific polymerase chain reaction) and protein expression (by Western blot) in tumor cell explants with respect to prediction of TMZ response and survival of GBM patients (n = 71). Methylated MGMT gene promoter sequences were detected in 47 of 71 (66%) cases, whereas 37 of 71 (52%) samples were scored positive for MGMT protein expression. Although overall promoter methylation correlated significantly with protein expression (χ² test, P < .001), a small subgroup of samples did not follow this association. In the multivariate Cox regression model, a significant interaction between MGMT protein expression, but not promoter methylation, and TMZ therapy was observed (test for interaction, P = .015). In patients treated with TMZ (n = 42), MGMT protein expression predicted a significantly shorter overall survival (OS; hazard ratio [HR] for death 5.53, 95% confidence interval [CI] 1.76–17.37; P = .003), whereas in patients without TMZ therapy (n = 29), no differences in OS were observed (HR for death 1.00, 95% CI 0.45–2.20; P = .99). These data suggest that lack of MGMT protein expression is superior to promoter methylation as a predictive marker for TMZ response in GBM patients.     

血清外泌体miRNA 对结直肠癌患者免疫调控及预后价值的研究

目的:研究血清外泌体miRNA 对结直肠癌患者免疫调控及预后价值。方法:本研究采取前瞻性病例对照研究,本次研究对象主要以2016年1月到2017年1月在我院进行诊断并治疗的结直肠癌患者180例作为研究对象,同期收集在我院进行肠镜检查,经病理确诊为大肠腺瘤患者60例以及同期健康体检的志愿者60例作为对照,比较三组患者以及不同疾病进展以及预后患者的miR-21、miR-92、miR-196a和miR-196b水平,研究miR-21、miR-92、miR-196a和miR-196b水平的联合检测对患者的不良预后的诊断价值。结果:结直肠癌组、大肠腺瘤组以及健康组的miR-21（F=18.47,P=0.000）、miR-92（F=16.68,P=0.000）、miR-196a（F=15.04,P=0.000）和miR-196b（F=16.31,P=0.000）水平之间的差异存在统计学意义,miR-21、miR-92、miR-196a和miR-196b水平从高到低依次为结直肠癌组、大肠腺瘤组以及健康组;Ⅲ-Ⅳ期、Ⅰ-Ⅱ期患者的miR-21（t=20.740,P=0.000）、miR-92（t=12.265,P=0.000）、miR-196a（t=4.114,P=0.000）和miR-196b（t=3.449,P=0.000）水平之间的差异存在统计学意义。miR-21、miR-92、miR-196a和miR-196b从高到低依次为Ⅲ-Ⅳ期、Ⅰ-Ⅱ期;通过对患者的随访分析,生存患者112例,死亡患者68例,生存组以及死亡组患者的miR-21（t=20.635,P=0.000）、miR-92（t=17.177,P=0.000）、miR-196a（t=12.974,P=0.000）和miR-196b（t=5.010,P=0.000）水平之间的差异存在统计学意义。miR-21、miR-92、miR-196a和miR-196b从高到低依次为死亡组、生存组;通过联合检测效能进行分析,miR-21、miR-92、miR-196a和miR-196b的联合检测对于结直肠癌组患者的特异度显著高于单独检测,通过ROC曲线分析,对于结直肠癌患者的预测分析,miR-21、miR-92、miR-196a和miR-196b的临界值分别为15.63、9.98、1.77、4.02。结论:血清外泌体miRNA 对结直肠癌患者免疫调控及预后具有重要价值,可作为日后诊断的重要依据。     

室管膜下区放疗对胶质母细胞瘤患者预后作用分析

目的探讨室管膜下区（SVZ）放疗对胶质母细胞瘤（GBM）患者预后作用,并分析影响GBM患者的预后因素。方法 回顾性分析2017—2020年南京医科大学附属肿瘤医院收治的52例GBM患者,根据同侧或对侧SVZ剂量中位值将患者分为高剂量组和低剂量组,比较两组患者生存差异并分析预后影响因素。结果 全组患者中位无进展生存（PFS）期17.1个月（95%CI为12.4~30.7）,中位总生存（OS）期38.3个月（95%CI为20.4~44.5）。单因素分析显示肿瘤是否累及SVZ、切除程度、MGMT基因甲基化状态是PFS的影响因素（P=0.039、0.009、0.039）。年龄、卡诺夫斯凯计分（KPS）、肿瘤是否累及SVZ、切除程度以及MGMT基因甲基化状态是OS的影响因素（P=0.018、0.043、0.038、0.020、0.019）。将SVZ剂量作为连续变量分析显示,SVZ剂量是PFS的影响因素（P<0.05）,而不是OS的影响因素（P≥0.05）。无论肿瘤是否累及SVZ,高剂量组和低剂量组生存均无显著差异。多因素分析显示肿瘤是否累及SVZ、MGMT基因甲基化状态是PFS的独立影响因素,同样也是OS的独立影响因素（均为P<0.05）。而SVZ剂量相关变量在多因素分析中均无统计学意义。结论 肿瘤累及SVZ的患者预后更差。增加同侧或对侧SVZ剂量并不能改善患者生存。SVZ放疗是否影响患者生存仍需前瞻性随机临床研究进一步证实。     

Prognostic impact of O6‐methylguanine‐DNA methyltransferase silencing in patients with recurrent glioblastoma multiforme who undergo surgery and carmustine wafer implantation

BACKGROUND:

O⁶‐methylguanine‐DNA methyltransferase (MGMT) is a key enzyme in the DNA repair process after alkylating agent action. Epigenetic silencing of the MGMT gene by promoter methylation has been associated with longer survival in patients with newly diagnosed glioblastoma multiforme (GBM) who receive alkylating agents. In this study, the authors evaluated the prognostic value of different biomarkers in recurrent GBM and analyzed the changes in MGMT status between primary tumors and recurrent tumors.

METHODS:

Twenty‐two patients who had recurrent GBM and who underwent surgery with carmustine wafer implantation were enrolled prospectively between 2005 and 2007. The authors investigated the correlation between MGMT silencing in the tumor at recurrence and survival taking into account other clinically recognized prognostic factors. MGMT status was determined by using methylation‐specific polymerase chain reaction analysis, a high‐throughput quantitative methylation assay, and immunohistochemistry. In addition, expression analyses of human mutL homolog 1, human mutS homolog 2, and tumor necrosis factor α‐induced protein 3 at recurrence were conducted with regard to their prognostic impact.

RESULTS:

The median progression‐free survival (PFS) and overall survival (OS) rates after recurrence were 3.6 months and 9.9 months, respectively, and the 6‐month PFS rate after recurrence was 27.2%. On multivariate analysis, only age (P = .04) and MGMT promoter hypermethylation at recurrence, as determined by MethyLight technology (P = .0012) and methylation‐specific polymerase chain reaction (MSP) analysis (P = .004), were correlated with better PFS. On multivariate analysis, only MGMT promoter hypermethylation at recurrence, as determined by using MethyLight technology (P = .019) and MSP analysis (P = .046), was associated with better OS.

CONCLUSIONS:

MGMT methylation status was an important prognostic factor in patients with recurrent GBM who underwent surgery plus carmustine wafer implantation; therefore, it was useful in predicting the outcome of GBM therapy at recurrence. Cancer 2009. © 2009 American Cancer Society.     

O6-methyl-guanine-DNA methyltransferase methylation in serum and tumor DNA predicts response to 1,3-bis(2-chloroethyl)-1-nitrosourea but not to temozolamide plus cisplatin in glioblastoma multiforme.

PURPOSE: In glioblastoma multiforme (GBM), the cytotoxic effect of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and temozolamide is dependent on O(6) alkylation, which correlates inversely with expression of the DNA repair enzyme O(6)-methyl-guanine-DNA methyltransferase (MGMT). Thus, MGMT assessment can be useful in predicting response in GBM, but the scarcity of neoplastic cells limits the practicality of MGMT assessment in these tumors. Although GBM grows within the skull, we investigated the concordance of methylation in glioma tissue, and paired serum DNA and the potential correlation with response and time to progression. EXPERIMENTAL DESIGN: Using MSP assay, we assessed the methylation of MGMT, p16, DAPK, and RASSF1A in tumor and serum DNA from 28 GBM patients treated with BCNU or with temozolamide plus cisplatin. RESULTS: The concordance between methylation in tumor and serum was highly significant. Overall, response plus stable disease was noted in 10 of 11 (90.9%) patients with MGMT methylation and in 5 of 14 (35.7%) patients without (P = 0.01). In the 16 patients treated with temozolamide plus cisplatin, no significant correlation between MGMT methylation status and response was observed, whereas in BCNU-treated patients, a significant difference was observed in favor of those with methylated MGMT. Time to progression was 29.9 weeks in 12 patients with MGMT methylation and 15.7 weeks in 10 patients without (P = 0.006). No correlation was observed between response or time to progression and p16, DAPK, or RASSF1A methylation. CONCLUSIONS: Methylated MGMT, p16, DAPK, and RASSF1A were found in serum DNA of GBM patients, with a good correlation between serum and primary tumor tissue. Serum MGMT methylation predicted response and time to progression in BCNU-treated GBM patients. The methylation-specific PCR assay in serum DNA could be a good predictive tool for selecting GBM patients to be treated with BCNU or alternatively with the combination of temozolamide plus cisplatin.     

miR-10b与乳腺癌侵袭及预后的相关性研究

背景与目的:miR-10b通过增加其下游转移基因RHOC的表达,影响肿瘤的转移和侵袭能力。本研究探讨miR-10b在乳腺癌石蜡组织中的表达及其与乳腺癌侵袭转移及预后的关系。方法:采用实时定量PCR(real-time qPCR)对60例乳腺癌患者原发肿瘤蜡块提取的RNA进行miR-10b表达水平的测定,MannWhitney-U非参数检验比较miR-10b表达水平和乳腺癌临床病理参数的关系,预后分析采用Kaplan-Meier生存分析和log-rank计算。结果:miR-10b表达水平与乳腺肿瘤的大小、淋巴结转移、组织学分级、激素受体状态、肿瘤病理分期、组织类型及是否复发等无明显关系(P>0.05)。Kaplan-Meier生存分析表明,miR-10b表达水平并不影响乳腺癌患者的生存期(P=0.485)。结论:miR-10b表达在乳腺癌侵袭转移中的作用有限,并不是影响预后的主要因素,尚不足以作为基于石蜡组织标本的乳腺癌预测预后指标。     

MGMT promoter methylation is predictive of response to radiotherapy and prognostic in the absence of adjuvant alkylating chemotherapy for glioblastoma

Hypermethylation of the O⁶-methylguanine-DNA-methyltransferase (MGMT) gene has been shown to be associated with improved outcome in glioblastoma (GBM) and may be a predictive marker of sensitivity to alkylating agents. However, the predictive utility of this marker has not been rigorously tested with regard to sensitivity to other therapies, namely radiation. To address this issue, we assessed MGMT methylation status in a cohort of patients with GBM who underwent radiation treatment but did not receive chemotherapy as a component of adjuvant treatment. Formalin-fixed, paraffin-embedded tumor samples from 225 patients with newly diagnosed GBM were analyzed via methylation-specific, quantitative real-time polymerase chain reaction following bisulfite treatment on isolated DNA to assess MGMT promoter methylation status. In patients who received radiotherapy alone following resection, methylation of the MGMT promoter correlated with an improved response to radiotherapy. Unmethylated tumors were twice as likely to progress during radiation treatment. The median time interval between resection and tumor progression of unmethylated tumors was also nearly half that of methylated tumors. Promoter methylation was also found to confer improved overall survival in patients who did not receive adjuvant alkylating chemotherapy. Multivariable analysis demonstrated that methylation status was independent of age, Karnofsky performance score, and extent of resection as a predictor of time to progression and overall survival. Our data suggest that MGMT promoter methylation appears to be a predictive biomarker of radiation response. Since this biomarker has also been shown to predict response to alkylating agents, perhaps MGMT promoter methylation represents a general, favorable prognostic factor in GBM.     

Clinical trial substantiates the predictive value of O-6-methylguanine-DNA methyltransferase promoter methylation in glioblastoma patients treated with temozolomide.

PURPOSE: In the setting of a prospective clinical trial, we determined the predictive value of the methylation status of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter for outcome in glioblastoma patients treated with the alkylating agent temozolomide. Expression of this excision repair enzyme has been associated with resistance to alkylating chemotherapy. EXPERIMENTAL DESIGN: The methylation status of MGMT in the tumor biopsies was evaluated in 38 patients undergoing resection for newly diagnosed glioblastoma and enrolled in a Phase II trial testing concomitant and adjuvant temozolomide and radiation. The epigenetic silencing of the MGMT gene was determined using methylation-specific PCR. RESULTS: Inactivation of the MGMT gene by promoter methylation was associated with longer survival (P = 0.0051; Log-rank test). At 18 months, survival was 62% (16 of 26) for patients testing positive for a methylated MGMT promoter but reached only 8% (1 of 12) in absence of methylation (P = 0.002; Fisher's exact test). In the presence of other clinically relevant factors, methylation of the MGMT promoter remains the only significant predictor (P = 0.017; Cox regression). CONCLUSIONS: This prospective clinical trial identifies MGMT-methylation status as an independent predictor for glioblastoma patients treated with a methylating agent. The association of the epigenetic inactivation of the DNA repair gene MGMT with better outcome in this homogenous cohort may have important implications for the design of future trials and supports efforts to deplete MGMT by O-6-benzylguanine, a noncytotoxic substrate of this enzyme.     

Correlation between O<Superscript>6</Superscript>-methylguanine-DNA methyltransferase and survival in elderly patients with glioblastoma treated with radiotherapy plus concomitant and adjuvant temozolomide

Epigenetic silencing of the O⁶-methylguanine-DNA-methyltransferase (MGMT) gene by promoter methylation is correlated with improved progression-free survival (PFS) and overall survival (OS) in adult patients with newly diagnosed glioblastoma multiforme (GBM) who receive alkylating agents. The aim of this study is to determine the correlation between MGMT and survival in elderly patients with GBM treated with radiotherapy (RT) and temozolomide (TMZ). Eighty-three patients aged 70 years or older with histologically confirmed GBM treated with RT plus TMZ between February 2005 and September 2009 were investigated in this study. The methylation status of the MGMT promoter was determined by polymerase chain reaction analysis. Median PFS and OS were 7.5 and 12.8 months, respectively. The MGMT promoter was methylated in 42 patients (50.6%) and unmethylated in 41 patients (49.4%). Median OS was 15.3 months in methylated patients and 10.2 months in unmethylated patients (P = 0.0001). Median PFS was 10.5 months in methylated tumors and 5.5 months in unmethylated tumors (P = 0.0001). On multivariate analysis MGMT methylation status emerged as the strongest independent prognostic factor for OS and PFS (P = 0.004 and P = 0.005, respectively). The results of the present study suggest that MGMT methylation status might be an important prognostic factor associated with better OS and PFS in elderly patients with GBM treated with RT and TMZ.     

Frequent MGMT (0(6)-methylguanine-DNA methyltransferase) hypermethylation in long-term survivors of glioblastoma: a single institution experience

Background

The aim of this retrospective study was to analyse the MGMT (0⁶-methylguanine-DNA methyltransferase) promoter methylation status in long-term surviving (≥ 3 years) patients with glioblastoma multiforme (GBM).

Methods

The methylation status of the MGMT promoter was determined by bisulfite modification of the DNA and subsequent methylation-specific polymerase-chain-reaction (MSP). DNA was extracted from routinely formalin-fixed and paraffin-embedded tumour tissue samples.

Results

MSP yielded interpretable results in only 14 of 33 (42%) long-term surviving patients with GBM. A methylated band was seen in 3 of 14, methylated as well as unmethylated bands in 8 of 14 and an only unmethylated band in 3 of 14 patients, thus, yielding MGMT promoter methylation in 11 of 14 patients. The two groups of patients with methylated and unmethylated MGMT promoter status were too small to draw any firm statistical conclusions.

Conclusions

Long-term surviving patients with GBM have very frequently intratumoural MGMT promoter methylation. This phenomenon discriminates long-term survivors from a non-selected group of patients with GBM. The standardization of the MSP for the determination of the MGMT promoter methylation status seems to be necessary in order to make this methodology a more reliable one.     

Current Progress on Understanding MicroRNAs in Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is an aggressive grade IV astrocytoma with a 1-year median survival rate despite current treatment modalities. A thorough understanding of the vast genetic aberrations and signaling pathways involved in gliomagenesis as well as heterogeneous clinicopathological presentation remains elusive. The recent discovery of microRNAs (miRs) and their capability of simultaneously regulating multiple downstream genes may play a key role in explaining the complex mechanisms underlying GBM formation. miRs are 19 to 25 nucleotide non-protein-coding small RNA molecules involved in the suppression of mRNA translation. This review will summarize and discuss the most recent findings regarding miRs in GBM including downstream targets, functional effects, and therapeutic potentials. Specifically discussed miRs include miR-7, miR-9/miR-9*, miR-10a/miR-10a*/miR-10b, miR-15b, miR-17-92, miR-21, miR-26a, miR-34a, miR-93, miR-101, miR-124, miR-125a, miR-125b, miR-128, miR-137, miR-146b-5p, miR-153, miR-181a/miR-181b, miR-196a/miR-196b, miR-218, miR-221/miR-222, miR-296, miR-302-367, miR-326, miR-381, miR-451, and let-7a. In addition to gene regulatory roles, miRs have demonstrated significant diagnostic, prognostic, and therapeutic potential. These small molecules may both help in the understanding of GBM and in developing new therapeutic options.     

Combined analysis of O6-methylguanine-DNA methyltransferase protein expression and promoter methylation provides optimized prognostication of glioblastoma outcome

Background

Promoter methylation of the DNA repair gene, O-6-methylguanine-DNA methyltransferase (MGMT), is associated with improved treatment outcome for newly diagnosed glioblastoma (GBM) treated with standard chemoradiation. To determine the prognostic significance of MGMT protein expression as assessed by immunohistochemistry (IHC) and its relationship with methylation, we analyzed MGMT expression and promoter methylation with survival in a retrospective patient cohort.

Methods

We identified 418 patients with newly diagnosed GBM at University of California Los Angeles Kaiser Permanente Los Angeles, nearly all of whom received chemoradiation, and determined MGMT expression by IHC, and MGMT promoter methylation by methylation-specific PCR (MSP) and bisulfite sequencing (BiSEQ) of 24 neighboring CpG sites.

Results

With use of the median percentage of cells staining by IHC as the threshold, patients with <30% staining had progression-free survival (PFS) of 10.9 months and overall survival (OS) of 20.5 months, compared with PFS of 7.8 months (P < .0001) and OS of 16.7 months (P < .0001) among patients with ≥30% staining. Inter- and intrareader correlation of IHC staining was high. Promoter methylation status by MSP was correlated with IHC staining. However, low IHC staining was frequently observed in the absence of promoter methylation. Increased methylation density determined by BiSEQ correlated with both decreased IHC staining and increased survival, providing a practical semiquantitative alternative to MSP. On the basis of multivariate analysis validated by bootstrap analysis, patients with tandem promoter methylation and low expression demonstrated improved OS and PFS, compared with the other combinations.

Conclusions

Optimal assessment of MGMT status as a prognostic biomarker for patients with newly diagnosed GBM treated with chemoradiation requires determination of both promoter methylation and IHC protein expression.     

宫颈癌组织miR-199b表达及其临床意义的初步分析

目的：研究miR-199b在宫颈癌组织中的表达及其临床意义。方法：利用实时定量PCR方法检测miR-199b在35例宫颈癌组织中的表达情况;采用x2检验分析miR_199b表达水平与各临床病理参数之间的关系;用Kaplan-Meier法分析miR-199b表达与宫颈癌患者生存期之间的关系。结果：与癌旁组织相比较,在35例肿瘤组织中,27例miR-199b高表达。miR-199b低表达患者平均生存时间为54．38个月（95％CI：42．90～65．85）,miR-199b高表达患者平均生存时间33．48个月（95％CI：25．75～41．20）。miR-199b在宫颈癌组织中的表达水平与患者的无进展生存率明显相关,P=0．031。结论：miR-199b表达高的患者预后较差。miR-199b可能是预测宫颈癌预后的标志。