Differential SPARC mRNA expression in Barrett's oesophagus

Barrett's oesophagus (BE) is the precursor lesion to adenocarcinoma of the oesophagus. Understanding of the molecular alterations in this multistage process may contribute to improved diagnosis and treatment. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that modulates cell adhesion and growth. Alterations in SPARC expression have been observed in a variety of solid tumours. The aim of this study was to assess the prevalence and timing of SPARC mRNA expression in Barrett's multistage disease and to investigate the impact of SPARC alterations on the development and progression of this disease. SPARC mRNA expression was measured using a quantitative real-time RT-PCR method in 108 specimens from 19 patients with BE without carcinoma, 20 patients with Barrett's-associated adenocarcinoma (EA), and a control group (CG) of 10 patients without evidence of gastro-oesophageal reflux disease. The median SPARC mRNA expression was significantly upregulated in BE tissues compared to paired normal oesophagus (NE) tissues for the BE group (P=0.004) and for the EA group (P<0.001). The SPARC mRNA expression was significantly higher in adenocarcinoma of the oesophagus compared to matching NE tissue and compared to Barrett's tissues in the EA group (P<0.001). Furthermore, SPARC expression values were significantly different between metaplastic and dysplastic Barrett's tissues (P=0.014). In histologically normal squamous oesophagus tissues obtained from carcinoma patients (EA group), the SPARC mRNA expression was significantly higher compared to NE mucosa from the BE group and the CG group (P=0.03). These findings suggest that the upregulation of SPARC mRNA expression is an early event in the development and progression of BE and EA, and that high SPARC expression may be a clinically useful biomarker for the detection of occult adenocarcinoma, and that a widespread 'field effect' is present in the NE of patients with oesophageal adenocarcinoma.     

Abnormal expression of the E-cadherin-catenin complex in dysplastic Barrett's oesophagus

It is now accepted that altered E-cadherin-catenin complex expression in oesophageal cancer correlates with clinical and pathological parameters, while abnormal E-cadherin expression occurs early in Barrett's oesophagus. We evaluated immunohistochemically the expression and cellular localization of alpha-, beta-, and gamma-catenin, and E-cadherin in 5 dysplastic and 26 non-dysplastic cases of Barrett's oesophagus. Usually all three catenins were localized at the cell membrane, as was E-cadherin. A similar staining pattern for E-cadherin and the catenins was observed in all cases of non-dysplastic Barrett's syndrome. However, 60% (3/5) of cases with dysplasia showed loss of membranous beta-catenin staining and diffuse cytoplasmic distribution, with predominantly nuclear localization in two cases. Membranous staining and concomitant cytoplasmic localization of E-cadherin, alpha-catenin and gamma-catenin were seen in one case with abnormal beta-catenin immunoreactivity. Our results indicate that altered subcellular distribution of beta-catenin occurs frequently in dysplastic Barrett's oesophagus and possibly reflects the signalling function of this molecule.     

The consumption of tobacco, alcohol and the risk of adenocarcinoma in Barrett's oesophagus

The relationship between tobacco, alcohol and the risk of oesophageal adenocarcinoma in Barrett's oesophagus was evaluated in an endoscopy-clinic-based case-control study of 30 histologically confirmed cases of adenocarcinoma and 140 controls with Barrett's oesophagus but no evidence of malignant lesions. Among the cases, 18 (60%) were non-smokers and 14 (47%) non-drinkers, the corresponding proportions in the controls being 52% and 44%. Thus, there was no apparent relation between tobacco, alcohol and the risk of adenocarcinoma of the oesophagus, the age- and sex-adjusted point estimates being 1.0 for moderate and 0.9 for heavy smokers, 0.7 and 1.5 respectively for moderate and heavy drinkers. Upper 95% confidence limits were 1.6 for ever-use of tobacco and 1.9 for ever alcohol drinking. The findings of this study, although based on a limited number of cases, indicate that alcohol and tobacco are unlikely to play a major role in the aetiology of adenocarcinoma in Barrett's oesophagus.     

Risk of oesophageal adenocarcinoma in individuals with Barrett's oesophagus

IntroductionRecent studies have indicated a lower incidence rate of oesophageal adenocarcinoma (OAC) in individuals with Barrett's oesophagus (BO) than most earlier studies. Our objective was to assess the risk of OAC in a Swedish unselected cohort of individuals with BO.MethodsThis population-based cohort study included all Swedish residents diagnosed with BO in 2006–2013, identified through the Swedish Patient Registry. The cohort members were followed from the date of first BO diagnosis until the first occurrence of OAC, high-grade dysplasia (HGD), death, emigration or end of study period. The main outcome was incidence rates with 95% confidence intervals (CIs) of OAC.ResultsAmong 7932 participants with BO and 18,415 person-years of follow-up, the overall incidence of OAC was 1.47 (95% CI 0.91–2.02) per 1000 person-years. When stratified into follow-up periods after BO diagnosis, the incidence rate of OAC was 15.53 (4.77–26.29) from 7 to 30 d, 4.10 (0.82–7.38) from 31 to 100 d, 1.87 (0.00–3.99) from 101 d to 6 months, 1.44 (0.18–2.70) from >6 months to 1 year, 0.94 (0.36–1.53) from >1 year to 3 years and 2.17 (1.14–3.21) from >3 years to the end of follow-up. The median follow-up time was 2.13 person-years.ConclusionThis population-based study indicates that OAC is primarily diagnosed during the first months following an initial diagnosis of BO. This could justify a changed surveillance strategy of BO with a repeated thorough endoscopy shortly after initial BO diagnosis to identify prevalent early OAC or HGD.     

表达谱基因芯片在肿瘤分子分型中的应用

基因芯片、DNA微阵列、cDNA微阵列、寡核苷酸微阵列是近几年发展起来的前沿生物技术.在基因芯片技术中,表达谱芯片以其大规模、高通量和平行处理的优点,为研究肿瘤发生发展中的基因开关及表达程度提供了强有力的工具,并可随时获取肿瘤细胞生长各期与肿瘤生长相关基因的表达模式,从而使肿瘤的分子分型成为可能.现对表达谱基因芯片技术在肿瘤分子分型中的应用作一简要概述.     

The minimal incubation period from the onset of Barrett's oesophagus to symptomatic adenocarcinoma

Background:

The interval between the onset of Barrett''s oesophagus (BO) and oesophageal adenocarcinoma (OAC) can be termed the incubation period. However, the unrecorded onset of BO precludes its direct observation.

Methods:

Determining the range of intervals between BO diagnosis and OAC within the longest observational BO follow-up study. Exclusion criteria were presence of high-grade dysplasia (HGD) or OAC at baseline, death within <2 years of BO diagnosis, oesophagectomy without HGD/OAC and loss to follow-up. A total of 133 patients (M/F 73/60) were taken into account.

Results:

In 1967 person years of follow-up there were 13 cases of HGD/OAC, (0.66% p.a.; 95% CI 0.58–0.74), 96 patients died without HGD/OAC and 24 survived without HGD/OAC. The mean intervals between BO diagnosis and either HGD/OAC, death or end of follow-up were 10.8, 12.6 and 25.5 years, respectively, and the mean ages at endpoint were 72.5, 80.0 and 68.3 years, respectively. The survivors without HGD/OAC had a lower age at BO diagnosis (mean 42.8 vs 61.2 and 67.4 years, P<0.001). Baseline presence of low-grade dysplasia was associated with progression to HGD/OAC (log rank P<0.001).

Conclusion:

The Rotterdam BO follow-up cohort revealed a long incubation period between onset of BO and development of HGD/OAC, in patients without HGD/OAC at baseline as illustrated by 24 patients diagnosed with BO at a young age and followed for a mean period of 25.5 years. Their tumour-free survival established a minimum incubation period, suggesting a true incubation period of three decades or more.     

野生型p53对小鼠纤维肉瘤细胞线粒体功能的影响

目的观察野生型p53(Wtp53)基因对纤维肉瘤细胞线粒体结构和功能的影响, 探讨Wtp53的抑癌机制。方法 将5周龄昆明鼠随机分为单纯肿瘤组(对照组)和Wtp53基因治疗组(治疗组), 建立纤维肉瘤动物模型, 5d后治疗组动物于荷瘤局部注射表达Wtp53基因的重组腺病毒液0.1mL, 对照组同一部位注射等剂量生理盐水。两组动物于2次注射后10d、20d、30d分批处死, 量取肿瘤直径大小, Estabrook法分离提取线粒体, Clark氧电极法进行线粒体呼吸功能的测定, Reer法测定游离Ca²⁺浓度。结果 对照组肿瘤的凋亡指数明显低于治疗组。对照组中R₃显著高于治疗组;10天时两组R₄接近, 但20天和30天时治疗组R₄时相大大延长, 与对照组比较差异非常显著;对照组RCR随着时间的延长无明显变化, 治疗组中, RCR随时间延长而下降明显低于对照组;游离Ca²⁺浓度在10天时与对照组接近, 而后大幅度上升。结论 Wtp53明显降低线粒体呼吸功能, 增加线粒体的通透性, 从而在促进细胞凋亡方面发挥对纤维肉瘤的治疗作用。     

Endoscopic treatment of high-grade dysplasia and early cancer in Barrett's oesophagus

Barrett's oesophagus is the premalignant precursor of oesophageal adenocarcinoma. Non-dysplastic metaplasia can progress to low-grade dysplasia, high-grade dysplasia, and finally to invasive cancer. Although the frequency of adenocarcinoma in patients with Barrett's oesophagus is low, surveillance is justified because the outcome of adenocarcinoma is poor. Oesophagectomy remains the standard treatment for patients with high-grade dysplasia and superficial carcinoma. However, it has been associated with substantial morbidity and mortality and some patients are judged unfit for surgery. In this review, the present status of less invasive procedures is discussed. Endotherapy preserves the integrity of the oesophagus and allows a better quality of life to patients at low risk of developing lymph-node metastases. Opposition to endoscopic treatment is based mainly on the identification of undetected foci of cancer and high-grade dysplasia in oesophagectomy samples. The current ablative techniques used are photodynamic therapy, argon plasma coagulation, laser treatment, and endoscopic mucosal resection.     

The relationship between smoking and severe dysplastic disease in patients with Barrett's columnar-lined oesophagus

The aim of this study was to examine the relationship between smoking and oesophageal high-grade dysplasia (HGD) or adenocarcinoma (AC) in a large cohort of patients with Barrett's columnar-lined oesophagus (CLO). A total of 1280 patients diagnosed with CLO and registered with the UK National Barrett's Oesophagus Registry were included. Data, including smoking habits, were collected from the patient's notes and development of HGD or AC noted. Analysis was performed with SPSS using logistic regression for calculation of odds ratios (ORs) for development of HGD/AC. Data on smoking habits were available in 956 (74.6%) patients. There was no significant difference between smokers and nonsmokers in mean age (P=0.877) or length of follow-up (P=0.359). There was a significant risk of HGD/AC in patients with any history of smoking compared with those who had never smoked (P<0.001, OR 2.81). Ex-smokers of 10 years or more remained at a significantly higher risk of HGD/AC compared with those who had never smoked (P=0.001, OR 3.37). Current smokers were not at a significantly higher risk of HGD/AC compared with ex-smokers (P=0.857) nor were those who smoked at least 20 a day compared with those who smoked fewer than 20 a day (P=0.632). In patients with CLO, smoking appears to be a significant risk factor for the development of severe dysplastic disease; however, we did not observe a dose-dependent effect of smoking on progression of disease.     

Helicobacter pylori infection and the risks of Barrett's oesophagus: a population-based case-control study

Infection with Helicobacter pylori is associated with significantly reduced risks of oesophageal adenocarcinoma; however, few studies have examined the association between H. pylori and Barrett's oesophagus (BO), the precursor lesion. We explored the relationship between H. pylori infection and BO and sought to identify potential modifiers. We compared the prevalence of positive H. pylori serology among 217 adults with simple BO (without dysplasia), 95 with dysplastic BO and 398 population controls sourced from the metropolitan Brisbane area. We determined H. pylori serostatus using enzyme-linked immunosorbent assay. To estimate relative risks, we calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariable logistic regression in the entire sample and stratified by factors known to cause BO. The prevalence of H. pylori seropositivity was 12%, 3%, and 18%, respectively, among patients with simple BO, dysplastic BO and population controls. BO patients were significantly less likely to have antibodies for H. pylori (Simple BO: OR = 0.51, 95% CI: 0.30-0.86; Dysplastic BO: OR = 0.10, 95% CI: 0.03-0.33) than population controls. For simple BO, the association was diminished after adjustment for frequency of gastro-oesophageal reflux (GOR) symptoms. Adjustment for frequency of GOR symptoms did not substantially alter the observed effect for dysplastic BO. Although there was some variation in the magnitude of risk estimates across strata of age, sex, GOR symptoms and use of proton pump inhibitors or H2-receptor antagonists, the differences were uniformly nonsignificant. Helicobacter pylori infection is inversely associated with BO, and our findings suggest that decreased acid load is not the only mechanism underlying the H. pylori protective effect.     

Porphyrin biosynthesis in human Barrett's oesophagus and adenocarcinoma after ingestion of 5-aminolaevulinic acid

5-Aminolaevulinic acid (ALA)-induced porphyrin biosynthesis, which is used for ALA-based photodynamic therapy (ALA-PDT), was studied in tissues of 10 patients with Barrett's oesophagus (BE) and adenocarcinoma of the oesophagus (AC) undergoing oesophagectomy at a mean time interval of 6.7 h after the ingestion of ALA (60 mg kg(-1)). In BE, AC, squamous epithelium (SQ) and gastric cardia, the activities of the haem biosynthetic enzymes porphobilinogen deaminase (PBG-D) and ferrochelatase (FC) and the PDT power index--the ratio between PBG-D and FC in BE and AC in comparison with SQ--were determined before ALA ingestion. Following ALA administration, ALA, porphobilinogen, uroporphyrin I and PPIX were determined in tissues and plasma. The PDT power index did not predict the level of intracellular accumulation of PPIX found at 6.7 h. In BE, there was no selectivity of PPIX accumulation compared to SQ, whereas in half of patients with AC selectivity was found. Higher haem biosynthetic enzyme activities (i.e. PBG-D) and lower PPIX precursor concentrations were found in BE and AC compared to SQ. It is therefore possible that PPIX levels will peak at earlier time intervals in BE and AC compared to SQ.     

Non-steroidal anti-inflammatory drugs and risk of neoplastic progression in Barrett's oesophagus: a prospective study

BACKGROUND: Aspirin and other non-steroidal anti-inflammatory drugs (NSAID) probably decrease the risk of colorectal neoplasia; however their effect on development of oesophageal adenocarcinoma is less clear. We aimed to assess the role of NSAID in the development of oesophageal adenocarcinoma and precursor lesions in people with Barrett's oesophagus--a metaplastic disorder that confers a high risk of oesophageal adenocarcinoma. METHODS: We did a prospective study of the relation between duration, frequency, and recency of NSAID use and the risk of oesophageal adenocarcinoma, aneuploidy, and tetraploidy in a cohort of 350 people with Barrett's oesophagus followed for 20,770 person-months. We used proportional-hazards regression to calculate hazard ratios (HR) adjusted for age, sex, cigarette use, and anthropometric measurements. FINDINGS: Median follow-up was 65.5 months (range 3.1-106.9). Compared with never users, HR for oesophageal adenocarcinoma (n=37 cases) in current NSAID users was 0.32 (95% CI 0.14-0.76), and in former users was 0.70 (0.31-1.58). 5-year cumulative incidence of oesophageal adenocarcinoma was 14.3% (95% CI 9.3-21.6) for never users, 9.7% (4.5-20.5) for former users, and 6.6% (3.1-13.6) for current NSAID users. When changes in NSAID use during follow up were taken into account, the associations were strengthened: HR for oesophageal adenocarcinoma for current users at baseline or afterwards was 0.20 (95% CI 0.10-0.41) compared with never users. Compared with never users, current NSAID users (at baseline and follow-up) had less aneuploidy (n=35 cases; 0.25 [0.12-0.54]) and tetraploidy (n=45 cases; 0.44 [0.22-0.87]). INTERPRETATION: NSAID use might be an effective chemopreventive strategy, reducing the risk of neoplastic progression in Barrett's oesophagus.     

硫化镍转化人支气管上皮细胞基因差异表达芯片的研究

背景与目的近年研究发现硫化镍(NiS)可引起人支气管上皮细胞(humanbronchialepithelialcell,16HBE)发生恶性转化及转化细胞致癌性,其机制可能与NiS引起基因突变、多种转录因子的异常表达有关。为此,本研究利用NiS恶性转化的体外培养细胞模型,用cDNA微阵列技术研究经NiS转化后的16HBE细胞基因的差异表达,从基因组水平探讨NiS所致细胞恶变的相关基因差异改变。方法分别提取16HBE和经NiS单独处理发生转化的NiS16HBE细胞的总RNA,逆转录合成cDNA并以Cy3dCTP和Cy5dCTP荧光素分别标记制作探针。探针混合后与含4000个人类基因的芯片杂交。以ScanArray4000扫描仪扫描芯片,以GenPixPro3.0软件分析荧光信号,然后对差异表达的基因进行生物学信息分析。结果NiS16HBE细胞样本与16HBE细胞样本比较,呈现差异表达的基因有151个(3.78%),其中81个(53.64%)上调,70个(46.36%)下调。结论NiS的转化作用与应激反应基因、免疫相关基因、DNA合成和修复基因、代谢相关基因、原癌基因和抑癌基因等多类基因的异常表达有关。