Expression of S100A6 in primary and metastatic human gastric cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Some members of the S100 gene family have been suggested to be associated with cancer development and metastasis. Our previous cDNA micro-array studies have showed S100A6 expression is elevated in gastric cancer compared with that in paired normal mucosa. To validate our previous results and further investigate the possible role of S100A6 gene in gastric cancer, we carried out this detailed S100A6 expression analysis in more matched gastric cancer samples.</p><p><b>METHODS</b>S100A6 expression was detected in 20 paired fresh surgical samples of gastric tumor tissue and matched non-cancerous mucosa by QRT-PCR. A gastric cancer tissue microarray (TMA) containing 1020 duplicate matched normal mucosa, gastric cancer tissue and metastatic lymph node tissue cores from 208 gastric cancer patients was constructed. S100A6 expression was detected by immunohistochemistry and the correlation between S100A6 expression with clinicopathological factors and survival was analyzed.</p><p><b>RESULTS</b>As quantitated by QRT-PCR, S100A6 transcript level was elevated in 73.7% of the primary cancer lesions with an average 2.25-fold up-regulation than that in matched non-neoplastic mucosa. As displayed by immunohistochemistry, the positive rate of S100A6 in non-neoplastic mucosa, tumor lesions and metastatic lymph nodes was 34.3%, 84.1% and 90.9%, respectively. S100A6 expression level in cancer and metastatic lymph node was significantly higher than their matched non-neoplastic mucosa (P < 0.05). 65.5% of patients showed an increased S100A6 expression in cancer tissue compared with that in matched normal mucosa. S100A6 overexpression was associated with larger tumor size and deeper invasion (P = 0.022 and P = 0.009). No evidence was found for an association between S100A6 expression level and other variables, including tumor grade, nodal metastases, and TNM stage. There was no association between S100A6 expression level and survival. But compared with paired non-neoplastic mucosa, an increased S100A6 expression in tumor lesion predicated a decreasing suvival if compared with a decreased S100A6 expression, though the difference was statistically not significant.</p><p><b>CONCLUSION</b>Elevated expression of S100A6 gene may be an early event in the development and progression of gastric cancer. Further study of this gene may be helpful for understanding the nature of gastric carcinoma.</p>

Gene expression profile of human normal gastrointestinal tract tissues: bioinformatic study / 中国应用生理学杂志

<p><b>AIM</b>To identify up-regulated genes specific to human normal gastrointestinal tissues.</p><p><b>METHODS</b>Study was made on human normal tissue gene expression database open to the public. Tissue-specific genes were identified using one-tailed student T test. Online software including Ingenuity and KEGG were applied for physiological function analyses. Unsupervised two-way hierarchical clustering method was used to analyze the expression profile of stomach-specific genes in gastric cancer gene expression datasets.</p><p><b>RESULTS</b>The analyses identified 196 stomach-specific genes, 203 ileum-specific genes and 224 colon-specific genes, respectively. The gene expression profiles reflect major organ-specific physiological functions on the molecular level. Some putative oncogenes and tumor suppressor genes were found in the tissue-specific gene list. Hierarchical clustering analysis revealed that the stomach-specific genes were up-regulated in normal stomach tissues but down-regulated in stomach cancer tissues. The normal tissues clustered together, so did the cancer tissues. At the meantime, clustering could also distinguish the moderate and severe differentiated stomach cancer.</p><p><b>CONCLUSION</b>Human normal stomach, ileum and colon possess tissue-specific up-regulated genes, which are closely associated with physiological functions.</p>

Construction of a gastric cancer related gene GCRG213-specific siRNA expression vector and its effect on gastric cancer cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of gene GCRG213 siRNA transfection into gastric cancer cell line MKN45 cells.</p><p><b>METHODS</b>Two pairs of DNA sequences containing small hairpin structure to GCRG213 were designed and synthesized. The complement form was obtained by annealing and inserted into RNAi expression vector IMG-800. They are IMG-800-1 and IMG-800-2 correspondingly. The recombinant plasmid IMG-800-1, IMG-800-2 and the vector IMG-800 were separately transfected into MKN45 cells conducted by lipofectamine 2000. After G418 selecting, the cells were transfected steadily. Expression of GCRG213 was detected by semi-quantitative RT-PCR and Western Blot. The growth graph of six steady transfected cell cultures was protracted by cell counting. FACS was used to detect the cell cycle, and Annexin V FITC/PI double labeling were used to detect the effects on cell apoptosis in the above-mentioned cells. The clone formation rate in plate and in nude mice was tested to investigate the tumorigenic characteristics of the six steadily transfected cells in vitro and vivo.</p><p><b>RESULTS</b>Through sequencing, two pairs of DNA sequences containing small hairpin structure to GCRG213 were proved to be successfully cloned into siRNA expression vector IMG-800, correspondingly called IMG-800-1 and IMG-800-2. The recombinant plasmid IMG-800-1, IMG-800-2 and vector IMG-800 were transfected separately into MKN45 cells conducted by lipofectamine 2000. After G418 selecting, the cells were transfected steadily. Transfecting the siRNA vector (IMG-800-1, IMG-800-2 ) into the MKN45 cells significantly decreased the expression of GCRG213, at both mRNA and protein levels. The growth graph showed that the growth of IMG-800-1 and IMG-800-2 transfected cells were slower than that of vector transfected cells. The proportion of cells in G2/M and/or S phase decreased in the cells transfected with IMG-800-1 and IMG-800-2 and cell apoptosis increased. The average clone formation rate in vitro decreased in the cells transfected with IMG-800-1 and IMG-800-2, compared with those transfected with vector. In vivo, the time of tumor formation of IMG-800-1 and IMG - 800-2 transducted cells in nude mice was prolonged and the tumor size was smaller.</p><p><b>CONCLUSION</b>GCRG213 SiRNA transfection may induce inhibition of growth and proliferation of tumor cells, promote cell apoptosis, and inhibit the tumorigenicity in vitro and vivo.</p>

Gene expression profile of human adenocarcinoma by cDNA microarray and clustering / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the gene expression profile of human gastric adenocarcinoma by means of cDNA microarray and to analyze its biological significance.</p><p><b>METHODS</b>Paired tumor and non-tumor specimens from 18 cases of advanced gastric adenocarcinoma were studied. Total RNA was isolated and labeled by reverse transcription reaction with cy5 and cy3 for cDNA probe. cDNA microarrays containing 148 genes were hybridized with labeled cDNA probe. Data from cDNA microarray experiments were analyzed by average-linkage hierarchical clustering and significance analysis of microarrays (SAM).</p><p><b>RESULTS</b>Eighteen tumor and non-tumor specimens were clearly divided by clustering analysis. Three features of gene expression profile were found in gastric adenocarcinoma and non-tumor tissues. The profile of differential gene expression in tumor and non-tumor tissues was mainly shown in feature B and feature C. In gastric adenocarcinoma tissues, the expression of genes in feature B was lower and that in feature C was higher. The profile of differential gene expression among gastric adenocarcinoma tissues was found in feature A. In feature A, the profile of similar gene expression was found in paired tumor and non-tumor tissues from 13 patients. SAM analysis showed that 19 genes in feature B and 12 genes in feature C were of significant difference between tumor and non-tumor specimens. The expression levels of genes related to cell cycle, growth factor, cell adhesion, and matrix remodeling were higher or lower in gastric adenocarcinoma tissues.</p><p><b>CONCLUSION</b>Data from cDNA microarray experiments can clearly distinguish gastric adenocarcinoma from non-tumor tissues. The profiles show that gene expression in gastric adenocarcinomas is both homogeneous and heterogeneous. The homogeneous gene expression profile is found in both tumor and non-tumor tissues from 13 patients, suggesting that some gene aberrance is an early event of carcinogenesis of gastric adenocarcinoma. This study provides not only a new molecular basis for understanding biological properties of gastric adenocarcinoma, but also useful resources for future development of diagnostic and prognostic markers for gastric adenocarcinoma.</p>

Clinical analysis of 38 elderly patients with early double primary cancers / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the clinical features and proper treatment of 38 elderly patients with early double primary cancers.</p><p><b>METHODS</b>Thirty-eight elderly patients with early double primary cancers treated from January 1980 to March 2003 were retrospectively reviewed for involved organs, treatment and prognosis.</p><p><b>RESULTS</b>Digestive tract was the most frequently involved, followed by urogenital system and lung. Long-term results of endoscopic mucosal resection (EMR), operation and radiotherapy were superior to other methods. The prognosis of gastrointestinal carcinoma was better than that of prostate carcinoma and hematopoietic system. The operation rate decreased with increasing age. The 5-year survival rates of EMR, operation and radiotherapy were 85.7%, 71.1% and 75.0%, respectively. The medium survival time was 120 months in first cancer and 39 months in the second primary cancer. The 5-year survival rates of the first cancer and second primary cancer were 88.6% and 53.8%.</p><p><b>CONCLUSION</b>Yearly follow-up for elderly patients with endoscopy, beta ultrasonic scan and X-ray contribute to finding of early double primary cancers. Operation is the best treatment of early double primary cancers. Endoscopic mucosal resection is especially suitable for old patients with digestive tract and bladder cancer.</p>

Cloning and tissue expression analysis of up-regulated cDNA fragment in human gastric cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify novel human gastric cancer-associated susceptibility gene for early diagnosis and treatment of gastric cancer.</p><p><b>METHODS</b>A primer was designed for 3'-rapid amplification of cDNA end(RACE) and amplified fragments were cloned, then they were analyzed by sequencing. Compared with ESTs in Genbank, the EST fragment represented a novel gene. Combination of Northern blot and virtual Northern and multiple tissues Northern blot, expression of the cDNA in multiple normal and carcinoma tissues were analyzed.</p><p><b>RESULTS</b>One of the important cDNA bands with poly(A) tail was cloned. This band was named W41. Sequence analysis showed that W41 consists of 533 bp. Basic local alignment search tool analysis revealed that W41 has low identity with any genes from GenBank. This sequence data was submitted to GenBank with accession No. AF 325202. Northern blot revealed that W41 presented higher expression in gastric cancer tissue than in normal tissue. Multiple tissue Northern blot revealed that W41 presented higher expression in multiple cancers than in normal tissues. Virtual Northern revealed that the cDNA presented higher expression in tumor series analysis of gene expression libraries than in normal.</p><p><b>CONCLUSION</b>A novel human gastric cancer-associated cDNA fragment was identified.</p>

Expression of human anti-apoptotic gene survivin and its splice in normal human gastric tissue and gastric cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the expression of human anti-apoptotic gene survivin (SVV) in normal human gastric tissues and gastric cancer.</p><p><b>METHODS</b>SVV cDNA clone was obtained from human gastric cancer tissues by virtue of RT-PCR, using Dig-marked cRNA probe in situ hybridization to analyze its expression in normal human gastric tissues and gastric cancer.</p><p><b>RESULTS</b>Two SVV cDNA clones, SVV-S4A and SVV-S1B were obtained. The sequence of the former is identical to that of the well-known SVV cDNA; however, in the sequence of the latter, the third exon was missed, i.e., there are only two exons in SVV-S1B. In situ hybridization showed that SVV-S4A is mainly expressed in gastric cancer tissues whereas SVV-S1B is mostly expressed in normal gastric tissues.</p><p><b>CONCLUSION</b>There is difference between SVV-S4A and SVV-S1B in respect to their characteristics of expression in gastric cancer and normal gastric tissues.</p>