Prohibitin: a potential biomarker for tissue-based detection of gastric cancer

BACKGROUND: Prohibitin (PHB) was found to be overexpressed in breast cancer and thus is suggested as a biomarker in that disease. A few studies have investigated the PHB expression pattern in gastric cancer by two-dimensional gel electrophoresis. Uncertainties still existed on whether PHB expression could indicate the differentiation and apoptosis degree of gastric cancer and whether PHB protein as well as anti-PHB antibody could be a biomarker in the serum of the gastric cancer patient. In this study, the expression levels of PHB protein and mRNA of the tissues as well as PHB antigen and anti-PHB antibody in serum of patients with gastric cancer were systemically examined. METHODS: Immunohistochemistry and real-time PCR were used to detect expression levels of PHB protein and mRNA in gastric cancer tissues. Recombinant PHB antigen was identified by Western blotting. The expression of PHB antigen and anti-PHB antibody was investigated by ELISA and TRFIA. Bcl-2 expression was examined by immunohistochemistry. RESULTS: By immunohistochemistry and real-time PCR analyses, PHB protein and mRNA were both overexpressed in gastric cancer tissues compared to adjacent normal gastric tissues (P < 0.01). Moreover, an elevated PHB expression pattern paralleled the differentiation degree and Bcl-2 protein expression in gastric cancer. However, no significant differences of PHB protein and anti-PHB antibody expression were detected in serum of gastric cancer patients and that of healthy volunteers. CONCLUSIONS: These results indicated that PHB could be a potential diagnostic and differentiation biomarker of gastric cancer for tissue-based detection by immunohistochemistry and real-time PCR, but not for serum-based detection.     

Relationship between inactivation of p16 gene and gastric carcinoma

AIM: To investigate the relationship between inactivation of p16 gene and gastric carcinoma, and the mechanism of inactivation of p16 gene in gastric carcinogenesis. METHODS: 40 fresh tumor tissue specimens were taken from primary gastric cancer patients. Expression of P16 protein was detected by immunohistochemical method. Deletion and point mutation of p16 gene were analyzed by polymerase chain reaction (PCR) and DNA sequencing, respectively. RESULTS: The frequency of loss of P16 protein expression in the gastric cancer tissue, adjacent nontumor tissue, and distal normal tissue was 77.5 % (31/40), 55.0 % (22/40), and 17.5 % (7/40), respectively (P<0.005). Homozygous deletion of exon 1 and exon 3 was observed in two and three cases, respectively, giving an overall frequency of homozygous deletion of 12.5 %. All five cases had diffuse type gastric carcinoma. No p16 gene point mutation was detected. CONCLUSION: These findings suggest a close correlation between inactivation of p16 gene and gastric carcinoma. Further investigations are needed to testify the mechanism of inactivation of p16 gene in gastric carcinogenesis.     

丝裂原蛋白激酶抑制剂U0126对刚地弓形虫侵入宿主细胞的影响

目的观察丝裂原蛋白激酶(mitogenactivatedproteinkinases,MAPK)抑制剂对刚地弓形虫侵入宿主细胞的影响。方法以丝裂原蛋白激酶抑制剂U0126分别以不同浓度加入分孔培养的细胞中,于不同时间分别用吉氏染色和流式细胞仪(FCM)检测其宿主细胞感染速殖子的差异。结果吉氏染色检测在以U01261μM,10μM和100μM作用3小时下其感染率分别比对照组下降了20.22%(,P<0.01),52.91%(P<0.01)和75.27%(P<0.01);在作用6小时及9小时其感染率分别比对照组下降了32.88%(P<0.01),57.24%(P<0.01),79.21%(P<0.01)和41.26%(P<0.01),54.73%(P<0.01),80.80%(P<0.01)。FCM检测结果与之相似。结论U0126通过作用于MAPK信号传导途径而明显抑制弓形虫速殖子侵入宿主细胞。     

广州市孕妇碘营养状况研究

目的　了解广州市孕妇 (孕中、晚期 )碘营养状况。方法　用砷 -铈接触法测定尿碘 ,用放射免疫分析法 (RIA )测定血清甲状腺素 (T4 )、促甲状腺激素 (TSH )。结果　孕妇孕中期尿碘中位数为 2 4 9.3μg/ L ,<10 0μg/ L者占 4 .5 % ;孕晚期尿碘中位数为 2 4 1.2μg/ L ,<10 0μg/ L者占 12 .5 % ,两期尿碘值差异无显著意义 (P >0 .0 5 )。孕中期血清 T4 (15 7.0± 6 6 .4 ) nmol/ L ,在正常范围 (5 4～ 174 nm ol/ L )者占 5 8.2 % ,超过 174 nmol/ L者占38.8% ;孕晚期血清 T4 (12 4 .4± 5 9.4 ) nm ol/ L ,在正常范围者占 78.3% ,超过 174 nmol/ L者占 13.0 %。孕中期血清 TSH (中位数 3.9m U / L ) <5 m U / L者占 6 5 .7% ,>5 m U / L者占 34.3% ;孕晚期血清 TSH (中位数 6 .9m U / L ) <5 m U/ L者占 18.2 % ,>5 m U / L者占 81.8%。两期自身对照 TSH>5 m U / L与 <5 m U / L人数构成差异有非常显著意义 (P <0 .0 1)。结论　广州市孕妇碘营养状况良好 ;孕晚期血清 TSH>5 m U / L者 (81.8% )较多 ,与尿碘、T4 水平不一致 ,有待进一步研究     

中青年短暂性脑缺血发作患者临床特征分析

目的 总结分析中青年短暂性脑缺血发作患者的临床特征.方法 对1999年至2002年北京世纪坛医院确诊的短暂性脑缺血发作75例中青年(≤45岁)患者及90例老年(≥60岁)患者的发病危险因素、病史、临床表现以及实验室检查资料进行比较分析.结果 肥胖、高脂血症、睡眠障碍及血管病家族史在中青年组发生率高,高血压、缺血性心脏病、长期吸烟史、周围血管病以及颈动脉狭窄症在老年组发生率高,糖尿病及高尿酸血症在两组均占较高比例.椎基底动脉系短暂性脑缺血发作发生率中青年组低于老年组(P＜0.05).结论 中青年短暂性脑缺血发作者与老年患者比较有不同的发病危险因素和临床特征.其危险因素分析显示与不良生活方式有关,应给予早期干预.     

胰腺细胞的再生方法及相关机制

人体的细胞和器官具有较强的再生能力,作为重要的消化器官和多种代谢性激素合成的核心器官,胰腺在出生后再生能力明显不足。轻度急性胰腺炎或部分胰腺切除的患者都可通过促进存活的胰腺外分泌腺泡细胞再生而完全康复。胰岛β细胞数量相对或绝对减少引起的糖尿病,可通过刺激β细胞再生进行治疗。这些方法主要包括促进β细胞自身增殖和α细胞、δ细胞、胰腺导管上皮细胞、腺泡细胞以及其他消化腺细胞等细胞的转分化。通过不同的生物因子相关信号通路来调节β细胞的再生,从而恢复胰岛细胞功能,逆转或者延缓糖尿病的发生、发展,可为糖尿病的治疗提供新思路。     

肉碱棕榈酰转移酶1对60Co γ射线照射大鼠小肠上皮细胞IEC-6增殖的影响及相关机制研究

目的探索60Co γ射线诱导大鼠小肠上皮细胞(IEC-6)中CPT1A和CPT1B蛋白表达变化, 并进一步研究肉碱棕榈酰转移酶1(CPT1)变化对受照细胞增殖的影响及相关分子机制。方法 IEC-6细胞经棕榈酸、血清饥饿以及血清饥饿联合棕榈酸处理后, 给予0、5、10或15 Gy60Co γ射线照射, 照射后24 h收集细胞并提取蛋白, 利用Western blot方法检测CPT1A和CPT1B蛋白的表达水平变化;ETO是CPT1的小分子抑制剂, 利用克隆形成率实验和CCK-8实验分析ETO抑制CPT1对60Co γ射线照射IEC-6细胞存活及增殖的影响;利用Western blot方法检测5 Gy60Co γ射线照射ETO处理IEC-6细胞48 h后细胞外信号调节激酶1/2(ERK1/2)、c-Jun氨基末端激酶(JNK)蛋白表达及磷酸化水平变化。结果棕榈酸处理组中, CPT1A蛋白在15 Gy γ射线照射后表达量显著增加(t=-2.82, P<0.05)。血清饥饿处理组中, CPT1A蛋白在5、10和15 Gy γ射线照射后表达量明显升高(t=-3.28、-8.72、-8.67...     

可诱导表达BMP4的正常来源及隐睾特异性iPSCs的建立及分化研究

目的建立可诱导表达骨形态发生蛋白质4(bone morphogenetic protein 4,BMP4)的正常来源及隐睾特异性诱导多能干细胞(induced pluripotent stem cells,iPSCs),比较两者体外定向分化的差异,为研究部分隐睾患儿成年后不育的原因提供具有人类遗传背景的体外研究模型。方法①建立可诱导表达BMP4的正常来源及隐睾特异性iPSCs,将正常来源iPSCs作为对照组,隐睾特异性iPSCs作为隐睾组;利用多西环素(doxycycline,Dox)进行诱导,筛选出BMP4表达量最高的细胞株;②将外源性添加BMP4的正常来源iPSCs作为外源性添加BMP4组(外源组),将Dox内源诱导BMP4表达的正常来源iPSCs作为Dox内源诱导BMP4表达组(内源组),此两组共同作为实验组;在细胞形态和基因表达水平比较实验组两组间BMP4因子诱导效果的差异;③通过Dox诱导BMP4的表达、双氢睾酮(dihydrotestosterone,DHT)、全反式维甲酸(all trans retinoid acid,ATRA)组成的三步法诱导分化方案,逐步诱导人的正常来源及隐睾特异性iPSCs向生精细胞方向分化,在基因及蛋白水平进行检测,比较两株细胞在分化过程中的差异。结果①经Dox诱导后,在正常来源及隐睾特异性iPSCs两株细胞中均可检测到BMP4表达明显升高、同时多能性基因OCT4的表达均呈明显下降趋势,与d0相比差异具有统计学意义,其中对照组的3#细胞株与隐睾组的5#细胞株在Dox诱导后BMP4表达量最高;②与外源组相比,内源组的细胞株形态变化更为均一、同步,BMP4的基因表达量更高,两组间的差异具有统计学意义;③在向生精细胞诱导分化过程中,对照组及隐睾组细胞的DAZL和PRDM1的表达量在两组之间的差异均无统计学意义;隐睾组的VASA、SYCP3、ACROSIN和TEKT1的表达量于诱导d14和d21时均明显低于对照组,两组之间的差异具有统计学意义。免疫染色结果显示:DAZL的阳性率在对照组和隐睾组细胞间的差异无统计学意义;隐睾组的VASA和SYCP3的阳性率于诱导d14和d21时均明显低于对照组,ACROSIN的阳性率于诱导d21时明显低于对照组,差异均具有统计学意义。结论本研究为部分隐睾患儿成年后不育的原因提供了具有人类遗传背景的体外研究模型,为未来的进一步研究奠定了良好基础。