Prostate cancer genes associated with TMPRSS2�CERG gene fusion and prognostic of biochemical recurrence in multiple cohorts

Background:

Recent studies have indicated that prostate cancer patients with the TMPRSS2–ERG gene fusion have a higher risk of recurrence. To identify markers associated with TMPRSS2–ERG fusion and prognostic of biochemical recurrence, we analysed a cohort of 139 men with prostate cancer for 502 molecular markers.

Methods:

RNA from radical prostatectomy tumour specimens was analysed using cDNA-mediated, annealing, selection, extension and ligation (DASL) to determine mRNAs associated with TMPRSS2–ERG T1/E4 fusion and prognostic of biochemical recurrence. Differentially expressed mRNAs in T1/E4-positive tumours were determined using significance analysis of microarrays (false discovery rate (FDR) <5%). Univariate and multivariate Cox regression determined genes, gene signatures and clinical factors prognostic of recurrence (P-value <0.05, log–rank test). Analysis of two prostate microarray studies ({"type":"entrez-geo","attrs":{"text":"GSE1065","term_id":"1065"}}GSE1065 and {"type":"entrez-geo","attrs":{"text":"GSE8402","term_id":"8402"}}GSE8402) validated the findings.

Results:

In the 139 patients from this study and from a 455-patient Swedish cohort, 15 genes in common were differentially regulated in T1/E4 fusion-positive tumours (FDR <0.05). The most significant mRNAs in both cohorts coded ERG. Nine genes were found prognostic of recurrence in this study and in a 596-patient Minnesota cohort. A molecular recurrence score was significant in prognosticating recurrence (P-value 0.000167) and remained significant in multivariate analysis of a mixed clinical model considering Gleason score and TMPRSS2–ERG fusion status.

Conclusions:

TMPRSS2–ERG T1/E4 fusion-positive tumours had differentially regulated mRNAs observed in multiple studies, the most significant one coded for ERG. Several mRNAs were consistently associated with biochemical recurrence and have potential clinical utility but will require further validation for successful translation.     

Development of receptoral responses in pigmented and albino guinea-pigs (Cavia porcellus)

We describe the postnatal development of the electroretinogram (ERG) receptoral response in the guinea pig. In addition, the time course and nature of maturation was compared between albino and pigmented strains to consider the role that melanogenesis might have in this process. Electroretinograms were collected on groups of albino and pigmented animals from postnatal day (PD) PD1 to PD60. A-wave amplitudes and implicit times were extracted from filtered data (0–75 Hz). Receptoral components were modelled using the delayed gaussian model of Hood and Birch [1] fitted as an ensemble to the raw data. Guinea pigs show saturated amplitudes (Rm_P3) that are 50% of adult values at birth, these mature by PD12. Receptoral delay (t_d) also undergoes some postnatal maturation, while phototransduction gain (log S) is adult-like at birth. Albino animals had significantly (p<0.05) larger Rm_P3 and log S across all ages. Guinea pigs have significant postnatal development in their receptoral response. Maturation of Rm_P3 implies a postnatal increase in rod outer segment length. Whereas the adult values of log S implies a mature phototransduction process at birth. We argue that the likely cause for the larger log S of albino eyes is compatible with theories of increased levels of internal light. Whereas the larger Rm_P3, even after allowing for increased light effectiveness, may reflect a lower ocular resistance in albino eyes due to their lower levels of melanin. Furthermore, decreased Rm_P3 and log S with age is observed in the pigmented group only and is consistent with increased ocular resistance due to melanin development in this strain. This revised version was published online in July 2006 with corrections to the Cover Date.     

尿液中PCA3mRNA和融合基因TMPRSS2：ERGmRNA的检测在前列腺癌早期临床诊断中的应用

目的研究前列腺按摩后尿液中PCA3mRNA联合融合基因TMPRSS2：ERG亚型T1E4mRNA的定量检测在早期前列腺癌临床诊断中的应用价值。方法收集前列腺癌（PCa）患者53例和前列腺增生（BPH）患者37例,收集前列腺按摩后尿液,离心取细胞沉淀物,提取总RNA,用实时荧光定量RT—PCR的方法检测PSAmRNA、PCA3mRNA和T1E4mRNA的含量,以PSAmRNA来校正尿液中的前列腺癌细胞。以PCA3mRNA／PSAmRNA表示PCA3mRNA的含量,以T1E4mRNA／PSAmRNA表示融合基因T1E4mRNA的含量。用ROC曲线对T1E4mRNA及PCA3mRNA诊断PCa的性能进行分析。结果尿T1E4mR．NA／PSAmRNA比值诊断PCa的ROC曲线下面积（AUC）为0．802（95％CI：0．709～0．895）,以0．007为截断值时,其诊断前列腺癌的敏感度和特异度分别为56．6％和94．6％。尿PCA3mRNA／PSAmRNA比值诊断PCa的ROC曲线下面积（AUC）为0．646（95％CI：0．533—0．758）,以0．001为截断值时,其诊断前列腺癌的敏感度和特异度为47．2％和73．0％。PCa组PCA3mRNA（P=0．009）及T1E4mRNA（P=0．000）的含量均高于BPH组,T1E4mRNA联合PCA3mRNA定量检测的敏感度为81．1％,比单独应用PCA3mRNA和T1E4mRNA检测的敏感度分别提高了33．9％和24．5％。结论前列腺癌按摩后尿沉渣中可以检测到TMPRSS2：ERG亚型T1E4mRNA,联合PCA3mRNA和T1E4mRNA两个指标定量检测,可以显著提高检出前列腺癌的敏感度。此联合检测方法可以用于早期的前列腺癌诊断。     

Check size tuning of the pattern electroretingoram: a reappraisal

The pattern electroretinogram was recorded to checkerboard stimuli with a wide range of check sizes and two stimulus field sizes. Check sizes ranged from 0.25° to 7° (field size, 16°×14°) and 0.25° to 15° (field size, 32°×27°) in 14 and seven subjects, respectively. Reversal rate was 4.5/s. For minimal intrusion of blink artifacts the interrupted stimulation technique was employed. The P50 and N95 components of the pattern electroretinogram were evaluated separately. With both stimulus field sizes amplitude of P50 and N95 was maximal between 0.75° and 1°. With smaller check sizes the amplitude dropped monotonically. With larger check sizes field size played a role: with the 16°×14° field, P50 gradually dropped to 89% from 1° to 7°, which was paralleled by N95 only up to 7°, where N95 dropped to 81% (p<0.05). With the 32°×27° field, there was no significant difference in size dependency between P50 and N95 for large checks, both components staying constant from 1° to 15° We conclude that there is only minor large-check attenuation of the pattern electroretinogram, especially with a large field. The apparent field-size dependency may explain previous discrepancies in the literature.     

A selective blocker of Kv1.2 and Kv1.3 potassium channels from the venom of the scorpion Centruroides suffusus suffusus

A novel potassium channel blocker peptide was purified from the venom of the scorpion Centruroides suffusus suffusus by high-performance liquid chromatography and its amino acid sequence was completed by Edman degradation and mass spectrometry analysis. It contains 38 amino acid residues with a molecular weight of 4000.3 Da, tightly folded by three disulfide bridges. This peptide, named Css20, was shown to block preferentially the currents of the voltage-dependent K⁺-channels Kv1.2 and Kv1.3. It did not affect several other ion channels tested at 10 nM concentration. Concentration-response curves of Css20 yielded an IC50 of 1.3 and 7.2 nM for Kv1.2- and Kv1.3-channels, respectively. Interestingly, despite the similar affinities for the two channels the association and dissociation rates of the toxin were much slower for Kv1.2, implying that different interactions may be involved in binding to the two channel types; an implication further supported by in silico docking analyses. Based on the primary structure of Css20, the systematic nomenclature proposed for this toxin is α-KTx 2.13.     

氟哌啶醇对新西兰兔心室肌细胞钾通道基因表达的影响

目的研究氟哌啶醇对兔左心室肌细胞钾通道基因水平的影响,探讨氟哌啶醇致心律失常的分子机制。方法实验组分别耳缘静脉注射氟哌啶醇(Haloperidol,Hal)1,2,4mg.kg-1.d-1,假手术组注射2ml.d-1生理盐水,同时监测心电图。应用逆转录-聚合酶链反应技术(RT-PCR),对ERG、KvLQT1和mink的基因表达进行半定量分析。结果氟哌啶醇低、中、高剂量组KvLQT1、mink及ERG mRNA表达较正常组降低(P<0.05),假手术组与正常组差异无统计学意义(P>0.05)。结论氟哌啶醇可能通过降低IKr、IKs钾通道基因KvLQT1、mink及ERG的表达,而使钾离子外流减少,心肌细胞动作电位时程延长,增加QT间期延长诱发Tdp的风险。     

达那康对视网膜脱离术后视功能恢复的干预效果

目的　探讨银杏叶提取物 (达那康 )对视网膜脱离术后视网膜功能改变的干预效果。方法　采用前瞻随机对照研究的方法将 5 0例 ( 5 0眼 )视网膜脱离患者分为达那康用药组和对照组。应用视网膜电流图和光学相干断层扫描观察术后第 1、2、4和第 8周视网膜功能和形态的改变。结果　视网膜脱离术前对照组和用药组的年龄、性别和视网膜脱离病程均具有可比性。与术后第 1周的ERGb波相比较 ,用药组第 2周ERGb即有显著的改变 ,而对照组在第 8周ERGb波才有显著的改变。OCT检查黄斑部视网膜厚度的改变用药组在术后第 4周才有显著的改变 ,而对照组在术后第8周才有显著的改变。结论　达那康可能在一定程度上促进视网膜脱离术后视功能的恢复。     

Negative scotopic ERG and photopic ERG ON response impairment in a patient with normal dark adaptation

Purpose To present ocular findings in a patient who showed negative scotopic electroretinogram (ERG) and reduced ON response, but normal dark adaptation.Case An 18-year-old Japanese male patient who complained of severe asthenopia. His corrected visual acuities were 1.2 in both eyes. His fundi were normal. He had normal contrast sensitivity and normal dark adaptation.Methods The patients underwent ERG (including the standard protocol and photopic long flash recordings).Results The amplitudes of the rod ERG b-wave were reduced. The scotopic standard combined ERG response showed negative configuration. The photopic response to long flash revealed the reduced b-wave (ON response), while the amplitude of the first peak of the d-wave (OFF response) was within the normal range.Conclusions Postsynaptic abnormalities in both the rod and cone ON-pathways, which are often found in patients with night blindness, were suggested in the ERG findings, but the dark adaptation of our patient was normal. Neuromuscular evaluation of the patient and ophthalmological evaluation, including ERG, of his parents were normal. To our knowledge, the ophthalmological and electrophysiological findings of our patient cannot be attributed to any known clinical entity.     

Differences between pattern onset and pattern reversal retinal responses

The pattern-evoked electroretinogram was recorded to pattern onset-offset and pattern reversal stimuli in two color-normal subjects with either luminance contrast of black-red (600 nm) and black-green (526 nm) square-wave stripe patterns or color contrast red-green patterns. The size of the onset response shows a spatial tuning with luminance contrast patterns and only a simple low-pass filter function with color contrast patterns. The peak latency of the response to luminance contrast increases with increasing spatial frequency but stays constant with color contrast patterns. The size of the reversal responses, however, shows only a low-pass filter function under both contrast conditions. The peak latency to luminance contrast shows a slight increase and to color contrast it remains constant with increasing spatial frequency. The differences noted under the various stimulus conditions must take into account the possible effects of different luminance modulation depths of onset and reversal stimuli, the modulation transfer function of the eye, and the activity of luminance-antagonistic and color-antagonistic receptive fields.