Gene Expression Profile Differences in Gastric Cancer and Normal Gastric Mucosa by Oligonucleotide Microarrays

OBJECTIVE To study the difference of gene expression in gastric cancer (T) and normal tissue of gastric mucosa (C), and to screen for associated novel genes in gastric cancers by oligonucleotide microarrays. METHODS U133A (Affymetrix, Santa Clara, CA) gene chip was used to detect the gene expression profile difference in T and C. Bioinformatics was used to analyze the detected results. RESULTS When gastric cancers were compared with normal gastric mucosa, a total of 270 genes were found with a difference of more than 9 times in expression levels. Of the 270 genes, 157 were up-regulated (Signal Log Ratio [SLR] ≥3), and 113 were down-regulated (SLR ≤-3). Using a classification of function, the highest number of gene expression differences related to enzymes and their regulatory genes (67, 24.8%), followed by signal-transduction genes (43,15.9%). The third were nucleic acid binding genes (17, 6.3%), fourth were transporter genes (15, 5.5%) and fifth were protein binding genes (12, 4.4%). In addition there were 50 genes of unknown function, accounting for 18.5%. The five above mentioned groups made up 56.9% of the total gene number. CONCLUSION The 5 gene groups (enzymes and their regulatory proteins, signal transduction proteins, nucleic acid binding proteins, transporter and protein binding) were abnormally expressed and are important genes for further study in gastric cancers.     

The Role of Expression of Mismatch Repair Proteins hMSH2 and hMLH1 in Gastric Carcinogenesis and its Clinical Significance

OBJECTIVE To investigate the expression of the mismatch repair proteins hMSH2 and hMLH1,and to examine the clinical significance of the intracellular expression site(ICES)in gastric carcinogenesis. METHODS Specimens from 172 cases of gastric cancer,151 tissues from paraneoplastic gastric mucosa and 34 from noncancerous gastric mucosa were collected in Dalain,China.An immunohistochemical method was used to determine the expression of the hMSH2,hMLH1 proteins and their ICES in the gastric mucosas. RESULTS The rate of hMSH2 expression in gastric cancers,paraneoplastic gastric mucosas and noncancerous gastric mucosas were respectively 69.8%,49.7%and 32.4%.The rate was significantly higher in gastric cancer compared to the latter two groups(P=0.000),but there was no obvious difference in the expression between the two latter groups(P=0.067). The hMLH1 protein expression rates were respectively 73.3%,57.6%and 41.2%in the above three groups.The expression was significantly higher in the gastric cancer group compared to the two latter groups(P=0.000),while there was no significant difference between the latter groups(P=0.082). There was no obvious correlation between the hMSH2 and hMLH1 protein expression rates and related factors,such as gender,age and differentiated level of gastric cancer etc.The cell-nuclear expression of the hMSH2 protein was respectively 70.0%,58.7%and 36.4%in the gastric cancer,paraneoplastic gastric mucosa and noncancerous gastric mucosa groups.The cytoplasmic expression rates were 30.0%,41.3%and 63.6%in the three groups. The cell-nuclear expression rate of the hMSH2 protein gradually decreased in the gastric mucosas in the fol owing order:cancer,paraneoplastic and noncancerous but cytoplasmic expression only increased slightly in these groups(r=0.161,P=0.020).There was no significant difference in the ICES of the hMLH1 protein among the three different gastric mucosas(P=0.659). CONCLUSION Simultaneous determination of the expression and ICES of the mismatch repair proteins hMSH2 and hMLH1 in the gastric mucosa may be helpful in detecting early gastric cancer.     

利用组织芯片技术研究胃癌及其癌前病变中Bax、p53、Survivin表达的关系及意义

Objective： To explore the relationship between expressions of apoptosis-related protein Bax, Survivin and p53 and the molecular mechanisms of carcinogenesis and progression of gastric carcinoma. Methods： Tissue microarray and immunohistochemistry were used in this study. Results： The positive rate of Bax protein in gastric cancer （17.7%, 17/96） was significantly lower than those in adjacent normal mucosa （51%）, intestinal metaplasia （69.2%） and dysplasia （75%）, P 〈 0.01. The positive rate of Survivin expression in gastric cancer （80.6%, 89/98） was significantly higher than that in adjacent normal mucosa （3.9%）, P 〈 0.01. The positive rates of Survivin expression in tumors with different organ metastases （in lymph node metastasis 86.2%, liver 100% and ovarian 100%） were statistically higher than in tumors without metastasis （64.3%）, P 〈 0.05. Bax expression was correlated with Survivin but not with rap53 that was closely related to Survivin expression （P 〈 0.05） in gastric cancer. Conclusion： The abnormal expressions of Bax, Survivin and rap53 were correlated with the tumorigenesis and progression of gastric carcinoma. P53 and Survivin genes may share the similar mechanism in regulating cell apoptosis, and because of the mutation, p53 gene may lower its down-regulation to Survivin expression.     

CONTRASTIVE STUDY OF THE TISSUE EXPRESSION AND SERUM CONCENTRATION OF PEPSINOGEN C IN GASTRIC MUCOSA DISEASES

Objective： To estimate the practical values of pepsinogen C （PGC） dynamic expression and the levels of serum pepsinogens in gastric cancer screening and diagnosis. Methods： 129 cases gastric mucosa biopsies and serum specimens were examined. The expression of PGC in stomach mucosa was detected by immunohistochemistry. The serum concentration of pepsinogen A （sPGA） and pepsinogen C （sPGC） were determined by ELISA. Results： The positive rate of PGC antigen expression decreased in superficial gastritis （100%）, gastric ulcer or erosion （80.00%）, atrophic gastritis （34.48%） and gastric cancer （11.43%） in sequence （P〈0.05）. There was no statistics difference in concentration of sPGA and sPGC among the above 4 groups. The ratio of sPGA/sPGC decreased in superficial gastritis, gastric ulcer or erosion, atrophic gastritis and gastric cancer in sequence （P〈0.05）. There was specific correlation between the expression of PGC in stomach mucosa and the levels of sPGA/sPGC ratio in serum （rs =0.297, P=0.001）. Conclusion： Tissue expression of PGC has close relationship with different gastric diseases. The ratio of sPGA/sPGC is relative with the tissue expression of PGC antigen and may be a convenient and economic maker in screening and diagnosis of gastric cancer.     

Expression and clinical significance of REGγ in gastric cancer tissue and variously differentiated gastric cancer cell lines

OBJECTIVE To evaluate the REGγ expression in gastric cancer tissue and gastric cancer cell lines of various differentiation levels and its clinical significance. METHODS Immunohistochemistry was used to detect the expression of REGγ protein in 70 specimens of gastric cancer and 30 specimens of normal gastric mucosa. The relationship between the expression of REGγ protein and the biological behaviors of gastric cancer was analyzed. RT-PCR and Western blot were used to detect the mRNA level and the protein expression of REGγ in normal gastric cell line GES-1, well differentiated gastric cancer cell line MKN-28, moderately differentiated gastric cancer cell line SGC-7901 and poorly differentiated gastric cancer cell line BGC-823. RESULTS The expression rate of REGγ protein in gastric cancer tissue （52/70, 74.29%） was significantly higher than that in normal gastric tissue （12/30, 40%） （P 〈 0.01）. The expression rate of REGγ was correlated with tumor size （P 〈 0.01）, lymph node metastasis （P 〈 0.05）, differentiation degree （P 〈 0.01）, infiltration depth （P 〈 0.01） and distant metastasis （P 〈 0.05）. RT-PCR analysis showed that the expression of REGγ mRNA was 0.459 ± 0.079 in the normal gastric mucosa cell ling 0.588 ±0.118 in the well differentiated gastric cancer cell line, 0.715±0.066 in the moderately differentiated gastric cancer cell line, and 0.873 ± 0.099 in the poorly differentiated gastric cancer cell line, showing a negative correlation between REGγ mRNA expression and differentiation level （P 〈 0.05）. Western blot analysis showed that the expression of REGγ protein was 0.712±0.065 in the normal gastric mucosa cell line, 1.176±0.185 in the well differentiated gastric cancer cell line, 1.533 ± 0.127 in the moderately differentiated gastric cancer cell line, and 2.061± 0.398 in the poorly differentiated gastric cancer cell line, showing a negative correlation between REGγ protein expression and differentiation level （P 〈 0.05）. CONCLUSION REGγ is expressed in gastric cancer tissue and normal gastric tissue. In gastric cancer tissues, REGγ expression is positively correlated with the tumor size, lymph node metastasis, differentiation degree, infiltration depth and distant metastasis. Detecting the expression of REGγ mRNA and protein is helpful for early diagnosis and predicting prognosis of gastric cancer.     

High Expression of the RECK Gene in Breast Cancer Cells is Related to Low Invasive Capacity

OBJECTIVE To investigate the expression of the RECK gene in human breast (cancer) cell lines, and to determine the relationship between RECK gene expression and the invasive capacity of the breast cancer cell lines. METHODS The invasive capacity of breast (cancer) cell lines including HBL-100, MCF-7 and MDA-MB-435S were determined by the Tran-swell method. The protein expression levels of RECK, MMP-2 and MMP-9 genes in these three cell lines were measured by immunocytochemical methods. The expressions of the RECK gene and protein level were measured by RT-PCR and Western blots in the cell lines respectively. RESULTS The order of the invasive capacity of the breast (cancer) cell lines was MDA-MB-435S, being the highest, and HBL-100, being the lowest. The invasive capacity difference between any two groups among the three groups was significant (P<0.01). The protein expression level of the RECK gene in the HBL-100 cell line was highest, and no expression was detected in MDA-MB-435S cells. Moreover, the expression of the RECK gene was negatively correlated with the expression of the MMP-2 and MMP-9 genes. The mRNA level of the RECK gene in HBL-100 cells was the highest, but no expression was found in the MDA-MB-435S cells (P<0.001). CONCLUSION There was a significant negative correlation between the expression level of the RECK gene and invasive capacity in vitro, and the RECK gene expression showed an inverse proportion to that of the MMP-2, MMP-9 genes.     

Down-regulated expressions of PPARγ and its coactivator PGC-1 are related to gastric carcinogenesis and Lauren＇s classification in gastric carcinoma

Objective： To explore the relationship between peroxisome proliferator activated receptor-gamma （PPARγ） and peroxisome proliferator-activated receptor-gamma coactivator-1 （PGC-1） expression in gastric carcinoma （GC）, and analyze their correlations with clinicopathological features and clinical outcomes of patients. Methods：The two-step immunohistochemical method was used to detect the expression of PPARγ and PGC-1 in 179 cases of GC, and 108 cases of matched normal gastric mucosa. Besides, 16 cases of fresh GC specimens and corresponding normal gastric mucosa were detected for PGC-1 expression with Western blotting. Results： The positive rates of PPART and PGC-1 expression were significantly lower in GC （54.75%, 49.16%） than in normal gastric mucosa （70.37%, 71.30%）, respectively （P〈0.05）. The decreased expression of PGC-1 in GC was confirmed ha our Western blot analysis （P=0.004）. PPAR7 and PGC-1 expressions were related to Lauren＇s types ofGC （P〈0.05）. Positive correlation was found between PPART and PGC-1 expression in GC （rk=0.422, P〈0.001）. The survival time of PPART negative and positive patients was 36.6±3.0 vs. 38.5_＋2.7 months, and no statistical difference was found between the 5-year survival rates of two groups （34.4% vs. 44.1%, P=0.522, log-rank test）; the survival time of PGC-1 negative and positive patients was 36.2±2.8 vs. 39.9±2.9 months, while no statistical difference was found between the 5-year survival rates of the two groups （32.0% vs. 48.2%, P=0.462, log-rank test） Conclusions＇. Decreased expression of PPARγand PGC-1 in GC was related to the Lauren＇s classification. Their expressions in GC were positively correlated, indicating that their fimctions in gastric carcinogenesis may be closely related.     

HPV16感染与P21基因失活在胃癌发生及预后中的意义

Objective： To investigate whether there is a synergistic carcinogenesis between the infection of human papilloma virus （HPV） and the P21 gene mutation in gastric cancer tissue and their relationship with prognosis of the patients with gastric cancer. Methods： By using PCR technique, HPV16 infection in 46 gastric cancer tissue samples was measured and by using immunohistochemical S-P method, the P21 gene mutation in gastric cancer was detected. All patients were regularly followed up for 3 years by writing letter or clinics, to detect the infection of HPV16 by PCR and the p21 gene mutation by immunohistochemical method in 46 gastric cancer tissue specimens. Results： The positive rate of HPV16 was 41.3% and the gene mutation rate of p21 was 52.17% respectively. The recurrence or remote metastasis was observed in 21 of 46 patients. The recurrence rate was 73.68% in the patients positive for HPV16 and 66.6% in those positive for p21 gene mutation. In 8 cases positive for both HPV16 and P21, 6 had recurrence or remote metastasis. Conclusion： The HPV16 infection may be one factor causing gastric cancer and it has a synergistic carcinogenesis with the p21gene mutation. The latter may be one of the prognostic indices in gastric cancer.     

胃癌组织中Ets-1的表达及其与血管生成临床病理特征和预后的关系

Objective To investigate the expression of Ets-I in gastric carcinoma,pars-cancerous tissue and metastatic lymph nodes,and to determine the relationship between Ets-1 expression and clinicopathological features,angiogenesis and survival of patients with gastric carcinoma.Methods Gastric carcinoma tissue microarray was used to determine Ets-I protein expression by SP immunohistochemical staining in 189 advanced gastric cancer,54 papacancerous tissues,41 metastatic lymph nodes and 32 control tissues.Results The positive rates for Ets-1 expression of the carcinoma,paracancerous and control tissues were 71.4 %,29.6% and 18.8%,respectively,with a significant difference among the three groups(P ＜0.01).In the cancer tissues,the positive rate of Ets-1 protein expression was significantly associated with depth of invasion and lymph node metastasis(P ＜0.01),but not associated with degree of differentiation,Lauren's histological type,sex,age,and size of tumor(P ＞0.05).The positive rates for Ets-1 expression of the 41 gastric cancer and 41 metastatic lymph nodes were significantly different(P ＜0.05).In metastatic lymph nodes,the positive rate for Ets-1 expression was higher.The MVD in Ets-1 positive tumors was higher than that in the Ets-1 negative tumors,with a significant difference(P ＜ 0.05).Kaplan-Meier survival analysis showed that the survival time of Ets-1-negative patients was longer than that of Ets-1-positive patients (P ＜0.05).Cox regression analysis showed that Ets-1 expression was not an independent prognostic factor of gastric carcinoma.Conclusion A higher expression of Ets-1 is involved in carcinogenesis,development,invasion,and metastasis of gastric cancer.Ets-1 plays an important role in angiogenesis in gastric cancer.Ets-1 is a useful marker for predicting the outcome for patients with gastric carcinoma,though it is not an independent prognostic indicator.     

胃癌患者外周血与癌组织基因差异表达比较

[目的]利用基因芯片技术筛选与早期胃癌癌变相关的基因.[方法]用U133A基因芯片分别检测胃癌组(T)、癌旁上皮组(P)和切缘正常胃黏膜上皮组(C)及胃癌患者外周血(WB)和正常对照组外周血(NB)的基因表达谱,对荧光强度进行扫描并数字化,用专业软件对检测结果进行分析.[结果]胃癌、癌旁和正常胃黏膜上皮相比,有327个基因共同表达上调,211个基因共同表达下调.胃癌和癌旁上皮同时有差异表达的基因中,在外周血也有差异表达,其中同时表达上调有39个,同时表达下调有4个.[结论]虽然在癌旁上皮病理组织图像上尚未见异常,但在基因表达水平上已经显示有多个与胃癌相关基因表达.尤其在患者外周血有核细胞的基因表达中,也发现某些基因与胃癌及癌旁基因差异表达正相关.提示这些基因可能与早期胃癌的启动和演化有关,通过外周血有核细胞基因芯片检查可能早期发现胃癌患者,提高患者的治愈率.     

应用cDNA微阵列基因芯片筛选胃低分化腺癌相关基因的研究

背景与目的：胃低分化腺癌癌变的分子机制至今不清楚,关键是未找到与胃低分化腺癌密切相关的基因.本研究拟建立胃低分化腺癌基因表达谱,筛选差异表达基因,进一步分析差异表达基因与胃癌发生、发展关系.方法：用含10 000个已知基因的cDNA微阵列分析胃低分化腺癌和癌旁正常胃黏膜基因表达谱的变化,免疫组化研究差异表达基因与胃癌的关系.结果：二倍以上的差异表达基因212个,其中在胃低分化腺中表达上调169个,表达下调43个.S-P免疫组化结果显示：EMS1蛋白表达定位于胞质,呈黄色至棕黄色;EMS1蛋白在20例正常胃黏膜阳性表达率为20%（4/20）,在146 例胃癌中阳性表达率为89.72% （131/146）;EMS1蛋白在胃癌中的表达高于正常胃黏膜（P＜0.001）.结论：发现EMS1与胃癌有关,为进一步寻找胃癌相关基因提供了重要的研究线索.     

胃腺癌差异表达基因的cDNA微阵列研究

目的:应用cDNA基因芯片研究筛选人胃腺癌相关差异表达基因, 探讨胃癌发生、发展的分子机制。方法: 运用含18 000个基因克隆的cDNA膜基因芯片,对6 对胃腺癌及正常胃组织标本分别进行杂交检测并对比分析。结果: 6 对人胃腺癌与相对应的胃正常组织相比较,筛选出在3~6 对标本中有2 倍以上改变的基因克隆共有103条(1 条在所有标本中均差异明显),其中胃癌组织表达上调基因56条, 胃癌组织表达下调基因47 条。结论: 人胃腺癌癌变是一个多基因参与的过程, 基因芯片技术是一种快速有效的筛选人胃腺癌差异表达基因的方法。     

PI3K/AKT2在胃癌组织表达及其与临床病理特征和生存期的关系

目的探讨PI3K、AKT2在胃癌、癌旁组织中的表达,分析其表达水平与临床病理特征和预后的关系。方法用组织芯片和免疫组织化学法检测189例胃癌组织、54例癌旁组织、32例正常胃黏膜中PI3K、AKT2的表达。结果胃癌、癌旁组织和正常胃黏膜PI3K阳性表达率分别是76.7%、25.9%和25.0%。AKT2阳性表达率分别是75.7%、27.8%和37.5%。胃癌组织PI3K表达与有无淋巴结转移、浸润深度、分化程度和Lauren分型有关（P〈0.05）,与肿瘤大小无关（P〉0.05）。AKT2表达与肿瘤大小、有无淋巴结转移、浸润深度、分化程度、Lauren分型有关（P〈0.05）。单因素生存分析显示,PI3K、AKT2阳性组对胃癌患者生存期的影响有统计学意义（P〈0.05）,Cox多元回归分析显示,AKT2的异常表达可以作为影响胃癌预后的独立因素（P〈0.05）。结论 PI3K/AKT2细胞信号传导通路参与胃癌的发生、发展、浸润转移,是胃癌发生的晚期事件。AKT2的表达可以作为胃癌预后的独立指标。     

胃癌及癌前病变组织中MUC5AC基因的异常表达及意义

目的：揭示正常胃粘膜、癌前病变和胃癌组织中ＭＵＣ５ＡＣ基因的表达与其临床病理分型之间的联系。方法：应用免疫组织ＳＰ法检测人正常胃粘膜、癌前病变粘膜以及胃癌组织中ＭＵＣ５ＡＣ核蛋白的表达。结果：人正常胃中的浅表１／３范围内广泛分布ＭＵＣ５ＡＣ基因产物（１００％）,肠化、不典型增生和胃癌组织中的表达阳性率分别是２９．６％、１００％和４０．０％。胃癌组织中ＭＵＣ５ＡＣ核粘蛋白的表达与胃癌患者的性别、肿瘤     

p21WAF1基因多态性与胃癌易感性关系

目的:探讨p21WAF1基因缺失与多态性及其意义。方法:采用聚合酶链反应-限制性片断长度多态性(PCR-RFLP)法和链霉菌抗生物素蛋白-过氧化酶(SP)法分别检测胃癌中p21WAF1基因缺失与多态性和p21蛋白表达。结果:PCR扩增显示,30例胃癌和45例非胃癌标本均无p21WAF1第二外显子缺失。PCR-RFLP发现胃癌和正常胃粘膜p21第二外显子多态性分别为26.7%(8/30)和8.9%(4/45),有显著性差异(P<0.05),且8例具多态性胃癌标本中的正常胃粘膜亦具有这种多态性。p21蛋白阳性表达率,胃癌为43.3%(13/30),非胃癌为100%(45/45),两者有显著性差异(P<0.05),具p21WAF1基因多态性胃癌为37.5%(3/8),与无多态性胃癌45.5%(10/22)无相关性(P>0.05)。结论:胃癌中p21WAF1基因无缺失,而存在多态性。p21WAF1基因多态性和p21表达与胃癌发生有关,但两者无相关性。WAF1     

胃癌前病变APC抑癌基因原位杂交光镜及电镜观察

目的 探讨胃癌前病变ＡＰＣ基因异常表达及其意义。方法 应用光镜及电镜原位杂交对胃癌前病变ＡＰＣ基因进行细胞和超微水平观察。结果 （１）ＡＰＣ基因阳笥率以正常胃黏膜最高,为８３．３％,轻、中、重度异型增生分别为７７．８％、６２．５％和２５．９％,重度者明显低于前两者,癌组织则更低,为６．７％～８．０％。（２）肠上皮化生中,ＡＰＣ基因阳性率大肠型高于小肠型,水完全性高于完全性,大肠型不完全性最高。（３     

胃癌患者原癌基因和抑癌基因的表达谱研究

目的 :用基因表达谱芯片对人正常胃和胃癌组织原癌和抑癌基因表达的差异进行研究比较。方法 :利用胃和胃癌组织的mRNA通过逆转录方法 ,将Cy3和Cy5 2种荧光分别标记到 2组cDNA上制成探针 ,然后和表达谱芯片进行杂交后扫描 ,通过计算机分析判定 2种基因是否在上述组织中存在差异表达。结果 :在 195条原癌及抑癌基因中 ,存在差异表达的共 13条 ,表达上调的 6条 (0 0 71% ) ,表达下调的 7条 (0 0 83% )。结论 :认为应用这种方法识别出的 2种基因对胃癌的诊断和治疗具有重要的潜在价值     

MAD2和p27在大肠癌组织中的表达及意义

目的探讨MAD2和p27表达与大肠癌发生、发展的关系。方法采用实时荧光定量PCR和免疫组织化学方法,检测大肠癌、腺瘤及正常大肠黏膜组织中MAD2表达,并对大肠癌组织中MAD2扩增产物进行测序。同时应用免疫组织化学方法检测大肠癌和正常组织中p27表达情况。结果大肠癌组织中MAD2阳性表达率明显高于腺瘤和正常大肠黏膜组织（66．7％VS39．6％VS22．9％）,三者间比较差异均有统计学意义（P〈0．01）。MAD2表达与大肠癌肿瘤分化和患者无瘤生存时间有关（P〈0．05）。大肠癌组织中未见MAD2基因突变。正常大肠黏膜组织中p27阳性表达率为81．3％,大肠癌中其阳性表达率为41．7％,两者比较差异有统计学意义（P〈0．05）。结论MAD2和p27基因表达与大肠癌的发生及发展有关。MAD2可能是大肠癌预后的1个重要指标。