Reduction of CAII Expression in Gastric Cancer: Correlation with Invasion and Metastasis.

OBJECTIVE: Human carbonic anhydrases II (CAII) gene plays an important role in different cancer. However, its relevance to gastric cancer (GC) remains unclear. In the present study, we aimed to investigate the expression of CAII in GC and explore its correlation with some clinicopathologic characteristics of GC. METHODS: The expression of CAII in 20 specimens of normal gastric mucosa, 38 specimens of intraepithelial neoplasia and 112 specimens of gastric carcinoma were detected by immunohistochemical techniques. Survival in GC with CAII expression was studied. RESULTS: The positive rate of CAII protein in normal gastric mucosa was significantly higher than that in intraepithelial neoplasia and gastric carcinoma (100% vs. 63.16% and 28.57%, P<0.001). The positive rate of CAII protein was significantly higher in gastric carcinoma at early stages than that at advanced stages (70.0% vs. 19.57%, P<0.001). The positive rate of CAII protein was significantly lower in gastric carcinoma with lymph node metastases than that without lymph node metastases (10.81% vs. 37.33%, P<0.05). Furthermore, the positive rate of CAII protein was significantly lower in poorly-differentiated gastric carcinoma than in moderately- or well-differentiated gastric carcinoma (15.94% vs. 31.03% or 60.00%, P<0.05). Moreover, CAII expression was not related with sex, age and tumor size. The patients with CAII-positive tumors showed a better survival rate than those with CAII-negative tumors (P=0.024, log-rank test). CONCLUSION: CAII expression was related with stages and lymph node metastases in gastric carcinoma. The reduction of CAII expression in GC might promote tumor cell motility and contribute to tumor growth and metastasis.

Inhibition of cell growth and invasion by epidermal growth factor-targeted phagemid particles carrying siRNA against focal adhesion kinase in the presence of hydroxycamptothecin.

BACKGROUND: Previous studies demonstrated the EGF-targeted phagemid particles carrying siRNA against Akt could be expressed efficiently in the presence of hydroxycamptothecin (HCPT). However, no significant cell growth inhibition was obtained. This study was to further investigate whether the EGF-targeted phagemid particles carrying siRNA would be a promising tool for anti-cancer siRNA delivery. RESULTS: We found that pSi4.1-siFAK phagemid particles could significantly inhibit the expression of focal adhesion kinase in the HCPT-treated cells. Moreover, we also observed that the particles could potently suppress cell growth and cell invasion. CONCLUSION: These results indicated that EGF-targeted phagemid particles might be a promising tool for anti-cancer siRNA delivery in the presence of HCPT.

Voxel-based morphology analysis of STZ-induced type 1 diabetes mellitus rats with and without cognitive impairment.

Incidence of diabetes has increased dramatically. Consequently, diabetes-induced cognitive impairment has attracted increasing attention. This study aimed to explore the changes in brain structure in the diabetic rats with and without cognitive impairment. Morris water maze method was used for screening the diabetic rats with/without cognitive impairment. These diabetic rats and controls were imaged using magnetic resonance imaging that segmented into gray and white matter, which was further analyzed using voxel-based morphology (VBM) and regions of interest (ROI) based image retrieval. The ROI results showed that the whole brain volume decreased in diabetic rats with/without cognitive impairment as compared to the control (P < 0.05). The VBM results showed differences in the caudate putamen and prefrontal cortex in the diabetic rats with/without cognitive impairment. The change in the brain of rats with cognitive impairment occurred primarily in the area associated with cognition, such as caudate putamen and hippocampus, and the bi-directional change occurred in the different area of hippocampus. The current results provided important imaging information for early diagnosis and timely treatment of diabetic cognitive impairment.

Expression of p21(WAF1) and p53 and polymorphism of p21(WAF1) gene in gastric carcinoma.

AIM: To investigate the relationship between expression of p21(WAF1) and p53 gene, and to evaluate the deletion and polymorphism of p21(WAF1) gene in gastric carcinoma (GC). METHODS: Expression of p21 and p53 proteins, and deletion and polymorphism of p21 gene in GC were examined by streptavidin-peroxidase conjugated method (SP) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) respectively. RESULTS: The expression of p21 and p53 was found in 100% (20/20) and 0% (0/20) of normal gastric mucosae(NGM), 92.5% (37/40) and 15.0% (6/40) of dysplasia (DP) and 39.8% (43/108) and 56.5% (61/108) of GC, respectively. The positive rate of p21 in GC was lower than that in NGM and DP (P<0.05), while the positive rate of p53 in GC was higher than that in NGM and DP (P<0.05). p21 and p53 were significantly expressed in 63.3% (19/30) and 36.7% (11/30), 35.0% (14/40) and 77.5% (31/40), 26.7% (4/15) and 80.0% (12/15), 30.8% (4/13) and 30.8% (4/13), and 20.0% (2/10) and 30.0% (3/10) of well-differentiated, poorly-differentiated, undifferentiated carcinomas, mucoid carcinomas and signet ring cell carcinomas. The expression of p21 in well-differentiated carcinomas was significantly higher than that in poorly-differentiated, un-differentiated, mucoid carcinomas and signet ring cell carcinomas (P<0.05). Contrarily, The expression of p53 was increased from well-differentiated to poorly-differentiated and un-differentiated carcinomas (P<0.05). The expression of p21 and p53 in paired primary and metastatic GC (35.3% and 70.6%) was different from non-metastatic GC (62.5% and 42.5%) markedly (P<0.05). The expression of p21 in invasive superficial muscle (60.0%) was higher than that in invasive deep muscle or total layer (35.2%) (P<0.05) and was higher in TNM stages I (60.0%) and II (56.2%) than in stages III (27.9%) and IV (22.2%) (P<0.05), whereas the expression of p53 did not correlate to invasion depth or TNM staging (P>0.05). The exoression patterns of p53+/p21-, and of p53-/p21+ were found in 5.0% and 82.5% of DP. There was a significant correlation between expression of p21 and p53 (P<0.05). But there was no significant correlation between expression of both in GC (P>0.05). There was no deletion in exon 2 of p21 gene in 30 cases of GC and 45 cases of non-GC, but polymorphism of p21 gene at exon 2 was found in 26.7% (8/30) of GC and 8.9% (4/45) of non-GC, a significant difference was found between GC and non-GC (P<0.05). There was no significant relation between p21 expression of polymorphism (37.5%, 3/8) and non-polymorphism (45.5%, 10/22) in GC (P>0.05). CONCLUSION: The loss of p21 protein and abnormal expression of p53 are related to carcinogenesis, differentiation and metastasis of GC. The expression of p21 is related to invasion and clinical staging in GC intimately. The expression of p21 protein depends on p53 protein largely in NGM and DP, but not in GC. No deletion of p21 gene in exon 2 can be found in GC. The polymorphism of p21 gene might be involved in gastric carcinogenesis.There is no significant association between polymorphism of p21 gene and expression of p21 protein.

Cloning and Expression Analysis of a Laryngeal Carcinoma Related Gene, LCRG1.

By screening a human adult cDNA library using a cDNA fragment (AF10056) as a probe, which is significantly down-regulated in laryngeal carcinoma and represents a novel gene, a cDNA, LCRG1(laryngeal carcinoma related gene 1) was identified, which was significantly down-regulated in 12 of 30(40%) primary laryngeal carcinomas and in 6 of 11(54.5%) various cancer cell lines. This gene, localized on chromosome band 17q12--21.1 by alignment of it with STS markers, was composed of six exons and spaned about 60 kb of genomic DNA with a 3.4 kb mature transcript. The putative protein encoded by this gene was 288 amino acid with no significant homology with any known proteins in databases. LCRG1 was expressed in many tissues, as shown by MTN blot analysis. These data suggest that LCRG1 is related to the laryngeal carcinoma.

Genome-wide screening and identification of long noncoding RNAs and their interaction with protein coding RNAs in bladder urothelial cell carcinoma.

To understand lncRNAs expression profiling and their potential functions in bladder cancer, we investigated the lncRNA and coding RNA expression on human bladder cancer and normal bladder tissues. Bioinformatic analysis revealed thousands of significantly differentially expressed lncRNAs and coding mRNA in bladder cancer relative to normal bladder tissue. Co-expression analysis revealed that 50% of lncRNAs and coding RNAs expressed in the same direction. A subset of lncRNAs might be involved in mTOR signaling, p53 signaling, cancer pathways. Our study provides a large scale of co-expression between lncRNA and coding RNAs in bladder cancer cells and lays biological basis for further investigation.

Differential gene and protein expression in primary gastric carcinomas and their lymph node metastases as revealed by combined cDNA microarray and tissue microarray analysis.

OBJECTIVE: To gain insight into the molecular events of lymph node metastasis of human gastric carcinoma. METHODS: The gene expression profile of five matched primary gastric carcinomas and their lymph node metastases was analyzed by complementary DNA (cDNA) microarray. Differential genes were identified in the metastatic and corresponding primary tumor pairs. Among the differentially expressed genes, carbonic anhydrase II (CAII) and insulin-like growth factor binding protein 4 (IGFBP 4) genes were detected by RT-PCR. CTTN protein expression was examined by tissue microarray. RESULTS: There was a high expression (over twofold) of 44 genes and a low expression (under twofold) of 32 genes in lymph node metastasis compared with primary gastric carcinoma, respectively. CAII mRNA was downregulated and IGFBP 4 mRNA was upregulated in paired lymph node metastases of gastric carcinomas. The overexpression of CTTN protein was related to the lymph node metastasis and the clinical stage of gastric carcinomas. CONCLUSION: This study showed that there is a low expression of genes relative to growth signal and immune response in lymph node metastases, and a high expression of genes relative to growth factor, cell cycle, cell motility and adhesion in lymph node metastases compared with primary gastric carcinomas. The expression of CTTN was related to the invasion and metastasis of gastric cancer.

[Expression and clinical significance of EMS1 gene in gastric carcinoma].

BACKGROUND & OBJECTIVE: EMS1 (chromosome eleven, band q13, mammary tumor and squamous cell carcinoma-associated gene 1) is correlated to the genesis, progression, invasion and metastasis of some malignancies. This study was to investigate the expression of EMS1 protein in gastric carcinoma, and to explore its correlation to the carcinogenesis of gastric carcinoma. METHODS: The expression of EMS1 protein in 20 specimens of normal gastric mucosa, 38 specimens of intraepithelial neoplasia, and 146 specimens of gastric carcinoma was detected by immunohistochemistry. RESULTS: EMS1 protein was expressed in cytoplasm. The positive rate of EMS1 protein was significantly higher in gastric carcinoma than in intraepithelial neoplasia and normal gastric mucosa (89.7% vs. 68.4% and 20.0%, P<0.001), and significantly higher in intraepithelial neoplasia than in normal gastric mucosa (P<0.001). The positive rate of EMS1 protein was significantly lower in the gastric carcinomas at early stages than in those at advanced stages (60.9% vs. 95.1%, P<0.001), and significantly higher in the gastric carcinomas with lymph node metastases than in those without lymph node metastases (96.8% vs. 77.0%, P<0.001). EMS1 protein expression had no correlations to sex, age, tumor differentiation and diameter. CONCLUSION: EMS1 protein expression is related to the carcinogenesis, lymph node metastasis and clinical stage of gastric carcinoma.

[Effects of diallyl disulfide on differential expression of apoptosis-associated genes in leukemia cell line HL-60].

BACKGROUND & OBJECTIVE: Diallyl disulfide (DADS) can induce apoptosis in various cancer cell lines in vitro. Leukemia is the most common pediatric malignancy. Recent studies have suggested that DADS can induce apoptosis in human leukemia cells, but its mechanisms remain unclear. This study was to investigate the biological effects of DADS on the apoptosis of human leukemia cell line HL-60, and explore its molecular mechanisms. METHODS: After treatment of DADS, cell apoptosis was verified by flow cytometry with Annexin V/PI staining, DNA agarose gel electrophoresis, transmission electron microscopy. The expression profile of apoptosis-associated genes in HL-60 cells, with or without 4-hour treatment of DADS (60 micromol/L), was identified by gene array. The up-regulated Fas-L gene and down-regulated Bag-1 gene were confirmed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: When treated with 15, 30, 60, 120 micromol/L DADS for 24 h, HL-60 cells presented obvious subdiploid peaks. When treated with 60 micromol/L DADS for 4, 8, 12, 24 h, early apoptotic cells were greatly increased. When treated with 60 micromol/L DADS for 24 h, DNA extracted from HL-60 cells displayed a characteristic ladder pattern on agarose gel electrophoresis; typical morphologic apoptotic changes were observed under electron microscope, including cell shrinkage, nuclear condensation, and formation of apoptotic bodies; the differential expression of 8 apoptosis-associated genes were found with gene array. The expression of Fas-L and Bag-1 detected by RT-PCR were consistent with those detected by gene array. CONCLUSION: DADS could induce apoptosis in HL-60 cells, which might be mediated by some specific genes and various signal transduction pathways.

[Isolation of differentially expressed cDNA sequences in human gastric carcinoma by cDNA microarray].

BACKGROUND & OBJECTIVE: Some gastric carcinoma-related genes haven't been identified yet. The study was designed to isolate and identify differentially expressed cDNA sequences in gastric carcinoma, and further clone gastric carcinoma-related genes. METHODS: The differences of gene expression profile between 30 gastric carcinoma tissues and their adjacent normal tissues were analyzed by cDNA microarray which representing about 4 892 cDNA sequences, the differentially expressed cDNA sequences were analyzed by bioinformatics, and selected cDNA sequences were confirmed by reverse transcripase-polymerase chain reaction (RT-PCR). RESULTS: A total of 33 differentially expressed cDNA sequences were identified in gastric carcinoma, among which 18 up-regulated in gastric carcinoma,while 15 down-regulated. MDSCBC11 clone,represented a novel gene, located in chromosome band 1p35-36, and significantly down-regulated in 13 of 30 (43%) gastric carcinomas. CONCLUSIONS: Some gastric carcinoma-related cDNA sequences have been identified,they might be involved in pathogenesis of gastric carcinoma. This study provides a useful clue for further clone gastric carcinoma-related genes.

[Cloning and expression analysis of lung carcinoma related gene HLCDG1].

BACKGROUND & OBJECTIVE: High frequent loss of hetero- zygosity (LOH) of 3p, 5q, 6q, 9p, 10q, 11p, 13q, 17p, and 19p in lung carcinoma was detected by comparative genomic hybridization (CGH) and genomic-wide scan for analysis of genetic alteration with microsatellite allelotying. It was indicated that there might be some other unknown tumor susceptible genes or suppressor genes likely to be involved in lung carcinoma development and progression. The aim of this study was to clone the full-length cDNA of LXDD1,an expressed sequence tag(EST) isolated by mRNA differential display, which is significantly down-regulated in lung carcinoma and represents a novel gene. METHODS: Differential expression of LXDD1 in lung carcinoma was confirmed by Northern blot analysis, the expression of the LXDD1 in human normal tissues and the size of the transcription of the LXDD1-representative gene were also determined using MTN (Multiple Tissues Northern Blots). The putative full-length cDNA of the EST-representative gene was cloned and analyzed by bioinformatics. In addition, differential reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of the novel gene in various cancer cell lines, primary lung carcinomas, and matched normal lung tissues. RESULTS: The full length cDNA with no homology to any reported genes in the database of GenBank was successfully cloned and named HLCDG1 (Human lung carcinoma deleted gene 1, GenBank accession number AF447582). A transmembrane protein with 166 amino acids was deduced to come from the open reading frame of the 3113 bp full-length cDNA, HLCDG1 gene was confirmed to be located at chromosome band 5q33 by alignment of electric polymerase chain reaction (e-PCR). CONCLUSION: HLCDG1 is a novel gene down-regulated in lung carcinoma, which may be involved in the development of lung carcinoma.

[Isolation and identification of cDNA sequence differentially expressed in human lung carcinoma].

BACKGROUND & OBJECTIVE: The molecular mechanism of the pathogenesis of lung carcinoma is unclear; because key genes related to lung carcinoma have not been identified. This study was designed to isolate and identify differentially expressed cDNA sequences in human lung carcinoma for cloning lung carcinoma-related genes. METHOD: Using mRNA differential display method combined with cloning and reserve Northern dot blot and sequencing and RT-PCR, differentially expressed cDNA sequences were isolated between two lung cancer cell lines, two adult lung carcinoma tissue and paired normal tissue of trachea epithelia. RESULT: Sixteen differentially expressed cDNA fragments were isolated, subsequent cloning of sixteen differentially expressed cDNA fragments were confirmed by reverse Northern dot blot and sequencing and BLAST analysis. Two of these were shown to be novel gene sequences that had not been reported. Eight of the remaining cDNA sequences homologize to known genes; additionally two differentially expressed cDNA sequences were confirmed by RT-PCR. CONCLUSION: Using mRNA differentially display, The authors had successfully isolated ten differentially expressed cDNA sequences from human lung carcinoma, these cDNA sequences might be involved in the pathogenesis of lung carcinoma.

[Effect of HLCDG1 gene transfection on growth of lung carcinoma cells].

BACKGROUND & OBJECTIVE: HLCDG1, which locates in chromosome 5q33 (between D5S436 and D5S470),is a novel gene that our laboratory has cloned recently. The expression of HLCDG1 gene was significantly down-regulated or deleted in the primary lung carcinoma. This study was designed to observe if HLCDG1 has the potential to suppress growth of lung carcinoma cells. METHODS: The recombinant plasmid, pcDNA3.1(+)/HLCDG1, was constructed and subsequently transfected into A549 cells through liposome transfection. The A549 cells stably expressing HLCDG1 gene were established by G418 selection. RT-PCR was used to demonstrate the expression of HLCDG1 gene. Furthermore, the cell proliferation assay, the soft agar assay, and the tumorigenesis assay were used to analyze the malignant phenotype of the HLCDG1-transfected cells. RESULTS: The HLCDG1-transfected cells exhibited the expression of HLCDG1 mRNA by RT-PCR. The population double time (PDT) of HLCDG1-transfected group, vector-transfected group, and nontransfected group were 70.0 hours, 43.3 hours, and 39.5 hours, respectively; the difference between HLCDG1-transfected group and the other two groups was significant (P< 0.05). The colony formation rates of HLCDG1-transfected group, the vector-transfected group, and nontransfected group were 8.5%, 29.0%, and 35.0%, respectively. The rate of HLCDG1-transfected cells was markedly lower than those of the other two groups (P< 0.05). Moreover, these clones were injected into athymic nude mice. After 43 days, they were killed, and their tumors were isolated. These tumors weighed 0.120g, 0.612g, and 0.924g, respectively. CONCLUSION: The expression of HLCDG1 in A549 cells may have the potential to suppress tumor cell growth and the tumorigenesis of A549 cells transplanted in nude mice. These results suggested that HLCDG1 gene might be a good candidate of tumor suppressor gene correlated with lung carcinoma.