蠕虫是比较生化的初级模型

寄生蠕虫已成为比较生化研究的初级模型。现发现寄生虫的多种代谢途径也可见于其它自由生活的无脊椎动物、一些鱼类及深水生活的哺乳动物等。寄生虫进行无氧代谢,产生能量有2条主要途径,这见于多种寄生蠕虫。这两种途径是糖酵解形成乳酸(如血吸虫成虫和一些丝虫)或经由延胡索酸还原酶系统。后一种途径中有些寄生虫仅能将葡萄糖代谢为琥珀酸     

柠檬酸盐对人胃癌细胞株SGC7901糖酵解的抑制作用及其机制研究

背景：糖酵解是肿瘤细胞的主要能量来源。柠檬酸作为三羧酸循环的中间产物,对糖酵解具有抑制作用。目的：研究柠檬酸盐对人胃癌细胞糖酵解的抑制作用及其机制。方法：柠檬酸三钠以不同浓度、不同作用时间处理人胃癌细胞株SGC7901,以生化法检测细胞培养液乳酸含量,CCK-8法检测细胞增殖率,Hoechst凋亡染色观察细胞凋亡情况,ELISA法检测细胞内磷酸果糖激酶（PFK）含量,蛋白质印迹法检测caspase-3、-9、cleavedcaspase-3、Bc1-2、细胞色素（Cyt）、缺氧诱导因子-1d（HIF-1仪）、葡萄糖转运蛋白-1（GLUT-1）蛋白表达,定量RT—PCR法检测PFK亚型mRNA表达。结果：在糖培养条件下,经不同浓度、不同作用时间柠檬酸三钠处理的SGC7901细胞,细胞培养液乳酸含量、细胞增殖率、细胞内PFK含量、caspase-3、-9、Bc1-2、HIF-10【、GLUT-1蛋白表达、肌肉型PFK（PFK—M）比例较空白对照组显著降低,cleavedcaspase-3、Cyt蛋白表达较空白对照组显著增高,细胞内可见典型凋亡征象,上述作用多呈时间和浓度依赖性。结论：柠檬酸盐对人胃癌细胞糖酵解的抑制作用与抑制PFK、HIF-1仪、GLUT-1表达相关。柠檬酸盐可通过启动内源性凋亡途径诱导人胃癌细胞凋亡。     

mTOR/PKM2和STAT3/c-Myc信号通路串话调节胃癌能量代谢和酸性微环境的机制研究

背景:c-Myc和PKM2在多种肿瘤中高表达,但m TOR/PKM2和STAT3/c-Myc信号通路对胃癌调节作用的研究不多见。目的:探讨m TOR/PKM2和STAT3/c-Myc信号通路串话调节胃癌能量代谢和酸性微环境的机制。方法:PKM2和c-Myc慢病毒转染人胃癌AGS和HGC-27细胞,构建敲减PKM2、c-Myc的细胞模型。采用CCK-8法检测细胞增殖能力,Transwell小室法检测细胞迁移能力,流式细胞术检测细胞凋亡,实时定量PCR和蛋白质印迹法分别检测PKM2、c-Myc、LDHA、STAT3、p-STAT3、GLUT-1 mRNA和蛋白表达,比色法检测乳酸和葡萄糖水平。结果:PKM2和c-Myc表达在胃癌细胞中上调。敲减c-Myc可抑制胃癌细胞增殖能力,细胞迁移能力明显降低,LDHA、GLUT-1蛋白表达明显降低,葡萄糖和乳酸含量明显降低。共同敲减PKM2和c-Myc对胃癌细胞增殖能力和糖酵解代谢的抑制作用更明显。m TOR/PKM2与STAT3/c-Myc信号通路之间存在相关性。结论:PKM2联合c-Myc可能成为胃癌新的治疗靶点。     

乳酸在胰腺癌中的研究进展

乳酸作为无氧糖酵解终产物, 既是糖异生前体的重要来源, 也是三羧酸循环的关键中间产物, 不仅在生理条件下发挥重要作用, 还介导肿瘤的发生和发展, 且其表达水平与肿瘤患者预后呈负相关。胰腺癌组织纤维基质丰富, 因而形成低氧乏养及乳酸丰富的微环境, 且乳酸在胰腺癌的发生、发展、转移过程中发挥着重要作用, 因此本文就肿瘤组织中乳酸的代谢机制以及其作为诊疗靶点在胰腺癌生物学行为中的作用进行综述。     

苹果酸钠对晕厥心肌线粒体酶系作用的实验研究

研究晕厥心肌线粒体琥珀酸脱氢酶 （SDH）、细胞色素氧化酶 （CCO）活性变化及苹果酸钠对其活性的影响。采用在体动物 （家兔 ）晕厥心肌模型 ,测定心肌 ATP含量及线粒体内 SDH,CCO活性变化 ,观察苹果酸钠对上述指标的作用。结果 :晕厥心肌线粒体重要酶 SHD,CCO的活性降低 ,苹果酸钠能促进其活性恢复 ,增加 ATP合成。结论 :补充重要中间代谢产物对晕厥心肌线粒体功能恢复具有重要意义。     

慢性胃炎及胃癌组织中膜联蛋白A1 mRNA 的表达变化及意义

目的：观察慢性胃炎及胃癌组织中膜联蛋白A1（ ANXA1） mRNA 的表达变化，并探讨其临床意义。方法采用q-PCR方法检测40例胃癌组织、20例慢性胃炎组织中的ANXA1 mRNA，并分析其与胃癌临床病理参数的关系。结果在胃癌组织中90％（36／40）高表达ANXA1 mRNA，慢性胃炎组织中75％（15／20）高表达，P＞0．05。 ANXA1 mRNA表达与胃癌临床病理特征之间无显著相关性（P均＞0．05）。结论 ANXA1 mRNA在胃癌组织及慢性胃炎组织中均高表达，慢性胃炎与胃癌的发生发展可能有潜在相关性。     

热量限制延长寿命机制的探讨—对糖代谢的影响

研究热量限制对雄性Ｆｉｓｈｅｒ－３４４大鼠一些糖代谢参数的影响。结果显示：热量限制鼠的血浆葡萄糖、血清胰岛素浓度较自由进食鼠显著降低；前者的肝重、体重、肝重与体重的比率显著小于后者；前者较后者有重大的肝糖原波动幅度；血清胰高血糖素浓度两组间差异无显著性（Ｐ＞０．０５）。上述结果表明：热量限制鼠能适应低浓度的葡萄糖与胰岛素环境，并在此情况下有效地利用葡萄糖；热量限制鼠有较强的肝糖原合成、储存、代谢能力。本研究提示：葡萄糖与胰岛素浓度的降低可能是热量限制可延长寿命的重要因素。     

腺病毒载体介导CagA基因表达对原代胃癌细胞糖酵解代谢酶表达的影响北大核心CSCD

目的研究过表达CagA对原代胃癌细胞糖酵解代谢酶表达的影响。方法构建CagA重组腺病毒载体pAdeno-MCMV-CagA-3Flag-IRES2-EGFP(pAdeno-CagA),转染HEK293细胞,包装腺病毒,以感染复数(Multiplicity of infection, MOI) 50感染原代胃癌细胞72 h,并用幽门螺杆菌(Helicobacter pylori,Hp)东亚株GZ7(CagA^+)以MOI 50感染原代胃癌细胞24 h,通过Western blot检测CagA和已糖激酶2(HK2)、葡萄糖转运蛋白1(GLUT1)、烯醇化酶1(ENO1)、丙酮酸激酶1/2(PKM1/2)、乳酸脱氢酶A(LDHA)糖酵解代谢酶的蛋白表达,采用流式细胞术检测胃癌细胞周期分布。结果成功构建了CagA重组腺病毒载体pAdeno-CagA,用pAdeno-CagA腺病毒和Hp GZ7感染原代胃癌细胞后糖酵解代谢酶HK2、ENO1、GLUT1的表达与空载组或Hp非感染组比较均显著下调(P<0.05)。与空载组比较,pAdeno-CagA感染胃癌SGC-7901细胞24、48、72 h,其G2/M期细胞百分比显著增加(P<0.05),感染72 h的空载组和CagA腺病毒组G2/M期的比值分别为16.90%和65.93%。结论 Hp通过CagA使原代胃癌细胞糖酵解代谢酶表达下调,可能与DNA损伤使细胞阻滞在G2/M期有关。     

血管紧张素转换酶抑制剂对缺氧心肌细胞的保护机制

目的：探讨血管紧张素转换酶抑制剂对缺氧心肌细胞的保护机制。方法：培养Ｗｉｓｔａｒ大鼠心肌细胞，７２小时后分为对照组、卡托普利组、依那普利拉组、缺氧组、缺氧加卡托普利组、缺氧加依那普利拉组。药物终浓度为１０－５ｍｏｌ／Ｌ。前３组采用有氧培养，后３组应用低糖无氧培养３０分钟。在ＭＰＶ３型显微分光光度计下测定心肌细胞内乳酸脱氢酶、琥珀酸脱氢酶相对含量，并取细胞上清液应用生化分析仪测定细胞内酶漏出情况。实验结果采用ｔ检验。结果：卡托普利和依那普利拉均可提高心肌细胞内乳酸脱氢酶含量（与对照组、缺氧组相比Ｐ＜０．０１）；减少缺氧心肌细胞内酶的漏出（与缺氧组相比Ｐ＜０．０１）。结论：血管紧张素转换酶抑制剂可明显改善缺氧心肌细胞糖代谢，加速糖酵解，减轻缺氧性损伤，对缺氧心肌细胞具有一定的保护作用。     

一氧化氮在胃癌转移中的意义

目的观测胃癌患者（包括伴有转移者和无转移者）外周血中一氧化氮（NO）浓度对胃癌转移的影响．方法24例临床胃癌患者，男21例，女3例，年龄44岁～68岁，平均年龄56岁．其中16例伴有局部淋巴结转移或全身远处转移，另外8例通过临床检查及病理切片未发现有转移．将16例伴有转移者设为转移组，8例无转移设为胃癌组；两组均于术前静脉采血离心后留取血清备检NO．另外抽取40例正常志愿者外周血作正常对照备检．NO的检测：用金属镉还原法检测血清中NO代谢产物硝酸盐的浓度．检测数据用x±s表示，结果统计用方差分析和q检验．结果转移组外周血中NO浓度为50．62umol/／L±7．8umol／L，胃癌组的NO浓度为70．76umol／L±9．7umol／L，正常对照组NO浓度为80．78umol／L±14．50umol／L．胃癌组和转移组NO浓度明显降低，胃癌组与正常组比较有显著性差异（P＜0．05），转移组与正常组比较有非常显著性差异（P＜0．01），转移组与胃癌组比较有显著差异（P＜0．05）．结论NO可能对胃癌转移有抑制作用．NO浓度降低会给胃癌的治疗带来不利影响．     

Metabolomic phenotype of gastric cancer and precancerous stages based on gas chromatography time-of-flight mass spectrometry

Background and Aim: To study the low‐molecular‐weight metabolites in blood plasma of patients with the progressive disease, gastric cancer, and to characterize different stages from chronic superficial gastritis (CSG) to chronic atrophic gastritis (CAG), intestinal metaplasia (IM), gastric dysplasia (DYS) and finally gastric cancer (GC). Methods: We applied gas chromatography time‐of‐flight mass spectrometry (GC/TOF‐MS) to determine metabolites levels in plasma obtained from 80 patients including 19 with CSG, 13 with CAG, 10 with IM, 15 with DYS and 22 with GC (nine preoperation and 13 postoperation). Principal component analysis (PCA) and statistics were used to differentiate the stages and to identify the markers of gastric cancer. Results: Totally, 223 peaks were detected in GC/TOF‐MS and 72 compounds were authentically identified. CSG showed distinct difference from the other groups of CAG, IM, DYS and GC, whose plots clustered closely. IM clustered closely to GC, suggesting similar metabolic patterns of them. Fifteen identified metabolites contributed most to the differentiating between CSG and GC, and characterized different stages of GC. Statistics revealed elevated levels of 2‐Hydroxybutyrate, pyroglutamate, glutamate, asparagine, azelaic acid, ornithine, urate, 11‐eicosenoic acid, 1‐monohexadecanoylglycerol and γ‐tocopherol, while downregulation of creatinine, threonate in GC group, indicating that GC patients were obviously involved in oxidative stress, and perturbed metabolism of amino acids and fatty acids. Conclusion: The metabolic phenotype of CSG is significantly different from GC, while that of IM is similar to it. The discriminatory metabolites characterizing progressive stages from CSG to GC might be the potential markers to indicate a risk of GC.     

胃癌及癌前病变中P27和Cyclin E蛋白的表达意义

目的:探讨P27和CyclinE蛋白在胃癌及癌前病变中的表达及其与胃癌病理参数之间的关系.方法:用免疫组化技术(SP法)对正常胃黏膜(normalgastricmucosa,NGM)、慢性浅表性胃炎(chronicsuperficialgastritisCSG)、慢性萎缩性胃炎(chronicatrophiagastritis,CAG)伴肠上皮化生、慢性萎缩性胃炎伴非典型性增生各20例和胃癌(gastriccarcinoma,GC)60例标本进行免疫组织化学染色,分析P27和CyclinE蛋白表达及其与胃癌临床和病理的关系.结果:各组胃组织中P27和CyclinE蛋白表达阳性率分别为NGM组100%和5%,CSG组85%和10%,CAG伴肠化组70%和20%,CAG伴不典型增生组45%和30%,胃癌组38.3%和40%.胃癌组和CAG伴不典型增生组P27阳性率显著低于其他组(P<0.05),CyclinE阳性率则显著高于其他组(P<0.05).P27和CyclinE在胃癌中的表达分别与肿瘤分化程度、浸润深度及肿瘤临床分期相关,P27蛋白的表达尚与有无淋巴结转移相关.P27和CyclinE蛋白在胃癌中的表达呈显著负相关(r=-0.768,P<0.05).结论:检测胃癌组织中P27和CyclinE蛋白的表达有助于判断肿瘤的进展程度,两者联合检测有助于判断肿瘤预后.     

Expression of ornithine decarboxylase in precancerous and cancerous gastric lesions

AIM: To investigate the expression of ornithine decarboxylase (ODC) in precancerous and cancerous gastric lesions. METHODS: We studied the expression of ODC in gastric mucosa from patients with chronic superficial gastritis (CSG,n = 32),chronic atrophic gastritis CAG,n = 43; 15 with and 28 without intestinal metaplasia (IM),gastric dysplasia (DYS,n = 11) and gastric cancer (GC,n = 48) tissues using immunohistochemical staining. All 134 biopsy specimens of gastric mucosa were collected by gastroscopy. METHODS: The positive rate of ODC expression was 34.4%,42.9%,73.3%,81.8% and 91.7% in cases with CSG,CAG without IM,CAG with IM,DYS and GC,respectively (P < 0.01),The positive rate of ODC expression increased in the order of CSG < CAG (without IM) < CAG (with IM) < DYS and finally,GC. In addition,ODC positive immunostaining rate was lower in well-differentiated GC than in poorly-differentiated GC (P < 0.05). CONCLUSION: The expression of ODC is positively correlated with the degree of malignity of gastric mucosa and development of gastric lesions. This finding indicates that ODC may be used as a good biomarker in the screening and diagnosis of precancerous lesions.     

Potential therapeutic significance of increased expression of aryl hydrocarbon receptor in human gastric cancer

AIM： To determine the functional significance of aryl hydrocarbon receptor （AhR） in gastric carcinogenesis, and to explore the possible role of AhR in gastric cancer （GC） treatment. METHODS： RT-PCR, real-time PCR, and Western blotting were performed to detect AhR expression in 39 GC tissues and five GC cell lines. AhR protein was detected by immunohistochemistry （IHC） in 290 samples： 30 chronic superficial gastritis （CSG）, 30 chronic atrophic gastritis （CAG）, 30 intestinal metapiasia （IN）, 30 atypical hyperplasia （AH）, and 70 GC. The AhR agonist tetrachlorodibenzo-para-dioxin （TCDD） was used to treat AGS cells. MTr assay and flow cytometric analysis were performed to measure the viability, cell cycle and apoptosis of AGS cells.RESULTS： AhR expression was significantly increased in GC tissues and GC cell lines. IHC results indicated that the levels of AhR expression gradually increased, with the lowest levels in CSG, followed by CAG, IM, AH and GC. AhR expression and nuclear translocation were significantly higher in GC than in precancerous tissues. TCDD inhibited proliferation of AGS cells via induction of growth arrest at the G1-S phase. CONCLUSION： AhR plays an important role in gastric carcinogenesis. AhR may be a potential therapeutic target for GC treatment.     

表皮生长因子和胃泌素在胃癌组织中的表达及意义

目的 探讨表皮生长因子(EGF)和胃泌素(GAS)在胃癌组织中的表达,及其相互关系与意义.方法 选取我院2003年1月～2009年12月经病理确诊的胃癌(GC)70例,慢性浅表性胃炎(CSG)25例,经过纳入标准及排除标准的筛选而作为研究对象.采用免疫组织化学Envision方法,检测EGF、GAS在各组胃黏膜组织中的...     

Expression of trefoil factors 1 and 2 in precancerous condition and gastric cancer

AIM: To study the expression of trefoil factor 1 (TFF1) and TFF2 in precancerous condition and gastric cancer and to explore the relationship between TFFs and tumorigenesis, precancerous condition and gastric cancer. METHODS: The expression of TFF1 and TFF2 was immunohistochemically analyzed in paraffin-embedded samples from 140 patients including 35 cases of chronic superficial gastritis (CSG), 35 cases of gastric ulcer (GU), 35 cases of chronic atrophic gastritis (CAG) and 35 cases of gastric cancer (GC). RESULTS: TFF1 and TFF2 were located in cytoplasm of gastric mucous cells. In CSG, GU, CAG and GC, the level of TFF1 expression had a decreased tendency (P<0.05). The expression of TFF2 was higher in GU than in CSG, but the difference was not significant. The expression of TFF2 also had a decreased tendency in GU, CAG, and GC (P<0.05). CONCLUSION: The reduced expression of TFF1 and TFF2 in precancerous conditions and gastric cancer may be associated with the proliferation and malignant transformation of gastric mucosa. More investigations are needed to explore the mechanism of TFFs and the relationship between TFFs and gastric cancer.     

hTERT、P53在胃癌及癌前病变中的表达及相关性研究

目的探讨端粒酶逆转录酶（hTERT）基因、p53蛋白在胃癌（GC）及癌前病变中的表达及相关性。方法采用免疫组化和原位杂交方法分别检测130例GC及癌前病变组织标本中p53和hTERT mRNA的表达。结果p53蛋白在慢性表浅性胃炎（CSG）、慢性萎缩性胃炎（CAG）、非典型增生（DYS）、GC中的表达率分别为5％、25％、50％、62．5％，其中GC与CSG、CAG比较有统计学差异：hTERT mRNA在CSG、CAG、DYS及GC中的表达率分别是0、10％、30％、78．75％，GC与CSG、CAG、DYS比较有统计学差异。p53阳性的GC组织中hTERT表达均为阳性，p53阴性的GC组织中hTERT阳性表达率为66．7％。结论hTERT是一个比p53更好的恶性肿瘤标记物；p53基因突变可导致端粒酶活化，但端粒酶激活可能不完全依赖于p53基因的调控。     

Association of the human leukocyte antigen class II alleles with chronic atrophic gastritis and gastric carcinoma in Koreans

OBJECTIVE: Gastric carcinogenesis is a multi‐step process and is influenced by several etiological agents, including the host's genetic factors. Since whether a patient remains with chronic superficial gastritis (CSG) or progresses to either chronic atrophic gastritis (CAG) or gastric carcinoma (GC) could be a genetic predisposition unique in each population, we hypothesized that host human leukocyte antigen (HLA) alleles could be discriminative in predicting the risk of CSG progression to precancerous CAG and GC in Koreans. METHODS: A total of 165 patients with gastric disorders (CSG, 62; CAG, 69 and GC, 34), were selected to investigate the association of HLA class II alleles with the progression of CSG to CAG or GC. HLA genotypes were obtained by the polymerase chain reaction‐sequence based typing method. RESULTS: The phenotypic frequencies of DRB1*1101 and DQA1*0505 were significantly higher in the CAG group compared to those in the CSG group. In the subjects with Helicobacter pylori (H. pypori) (+), the frequencies of DRB1*1501 and DQB1*0602 were significantly lower in the CAG compared to those in the CSG. Further analysis showed that sex (P < 0.05, OR= 0.41–0.42) and age (P < 0.05, OR= 1.05) also affected the risk of progression from CSG to CAG in H. pylori (+) patients carrying the DRB1*1501 or DQB1*0602 allele. Additionally, the frequency of DRB1*0404 in the GC group was significantly higher than that in the gastritis group. CONCLUSION: Our findings strongly imply an association between HLA class II alleles and the risk of CAG development and GC progression in Koreans.