Syncytins expression in cultured trophoblast cells according to differentiation status

Background  

Data of syncytin 1 and 2 env gene expression in human placenta and participation in the syncytialisation phenomena has been reported. However, there are not many studies on simultaneous changes in expression of both syncytins in culture. We sought evidence on the relative expression of syncytins and syncytin 1 receptors in trophoblast cell culture treated with a differentiation inducing factor (forskolin).     

Smad4 expression in gastric adenoma and adenocarcinoma: frequent loss of expression in diffuse type of gastric adenocarcinoma

Smads are signal transducers for the members of the TGF-beta superfamily. Of these Smads, Smad4 is essential for TGF-beta signaling. The purpose of this study was to elucidate Smad4 expression and localization in 65 gastric adenomas, 49 intestinal-type and 39 diffuse type of gastric adenocarcinomas (including 12 cases of fresh frozen tissue) using Real-time RT-PCR and immunohistochemistry. Real-time RT-PCR showed that intestinal type gastric adenocarcinomas have higher Smad4 mRNA expression than diffuse type gastric adenocarcinomas. Immunohistochemical stain for Smad4 revealed that expression of Smad4 was significantly lower in diffuse-type gastric adenocarcinoma than intestinal-type gastric adenocarcinomas. Also, higher Smad4 protein expression in intestinal type gastric adenocarcinomas than overall gastric adenoma was noted. The rate of reduced Smad4 expression was higher in advanced gastric cancer than early gastric cancer. These results suggest that Smad4 might play different roles in human gastric carcinogenesis, especially between intestinal type and diffuse type of gastric adenocarcinoma.     

Variation of HLA-ABC surface antigen expression on adenocarcinoma of the colon in correlation with the degree of differentiation

The expression of HLA class I antigens was tested on biopsy specimens originating from 90 patients suffering from adenocarcinoma of the colon. Three different samples were examined from each specimen: one from the tumor and the other two from the neighboring surrounding surgical margins. Twenty-seven out of 27 well-differentiated carcinomas were found highly positive for the presence of HLA class I antigens. Most of the moderately well differentiated tumors (37 out of 46) were weakly positive. None of the poorly differentiated tumors (n = 11) nor the mucin-producing tumors (n = 6) expressed HLA class I antigens. In 180 histologically normal colonic epithelia from patients suffering from adenocarcinoma of the colon (surgical edges free from tumorous tissue of the same specimens) no positive expressions were found. These results tend to suggest that class I HLA-ABC deficient, poorly differentiated tumors may possibly evade lethal immune aggression by HLA-restricted cytotoxic T cells and thus progress to overt malignancy. This negative expression may provide an explanation for the poorer prognosis observed among patients afflicted by a poorly differentiated adenocarcinoma or mucin-producing adenocarcinoma of the colon. Furthermore, these results tend to suggest that enhanced expression of HLA class I antigens on colonic epithelium could serve as a clinical laboratory indication for further examination looking for the possible emergence of neoplasm. If further verified, this may prove to serve as a predictive diagnostic tool for screening populations at risk.     

Differences of urease activity and expression of associated genes according to gastric topography

Background: We hypothesize that pH difference between acid‐secreting corpus and non‐secreting antrum might influence the activity of H. pylori’s urease and/or related genes. We therefore measured urease activity and the expression of amiE whose encoded protein that hydrolyzes short‐chain amides to produce ammonia. Materials and Methods: Fifty‐four patients were recruited into this study. Each gastroscopic biopsy specimen collected from the antrum and body of each patient was immediately used to measure urease activity using serial changes of urease activity (ammonia levels) during 60 minutes. Probe specific for amiE was labeled with a biotin nick‐translation kit and was used to detect expression of these genes (mRNA) in fresh‐frozen gastroscopic biopsy specimens using fluorescent in situ hybridization (FISH). Results: Urease activity at 60 minutes from the gastric antrum and body of all patients infected with H. pylori was 399.5 ± 490.5 and 837.9 ± 1038.9 μg/dL, respectively (p = .004). Urease activity in the antrum was correlated with H. pylori density. Urease activity or H. pylori density in the antrum was significantly correlated with chronic active inflammation; in contrast, this correlation was not found in the gastric body. The expression level of amiE was 1.5 times higher (p < .05) in the gastric body compared with the antrum. Conclusion: Topographically, the urease activity in body was much higher than in antrum. The expression level of amiE was higher in the gastric body compared with the antrum.     

Variation in gene expression patterns in human gastric cancers

Gastric cancer is the world's second most common cause of cancer death. We analyzed gene expression patterns in 90 primary gastric cancers, 14 metastatic gastric cancers, and 22 nonneoplastic gastric tissues, using cDNA microarrays representing approximately 30,300 genes. Gastric cancers were distinguished from nonneoplastic gastric tissues by characteristic differences in their gene expression patterns. We found a diversity of gene expression patterns in gastric cancer, reflecting variation in intrinsic properties of tumor and normal cells and variation in the cellular composition of these complex tissues. We identified several genes whose expression levels were significantly correlated with patient survival. The variations in gene expression patterns among cancers in different patients suggest differences in pathogenetic pathways and potential therapeutic strategies.     

Multidrug resistance gene and P-glycoprotein expression in gastric adenocarcinoma and precursor lesions

Overexpression of the Multiple Drug Resistance gene (MDR1) has been proposed as a major mechanism related to both intrinsic and acquired resistance to chemotherapeutic agents. The gene product is a membrane protein (P-glycoprotein), that acts as an energydependent drug efflux pump decreasing drug accumulation in resistant tumor cells. We have characterized MDR1 and P-Glycoprotein expression in human gastric adenocarcinoma and in precursor lesions. MDR1 mRNAs, analyzed by dot-blot technique, were detected in 9 of 10 non-tumoral gastric mucosae and in 8 of 10 gastric adenocarcinomas. Immunohistochemical analysis, using the MRK16 monoclonal antibody, revealed heterogeneous expression of P-Glycoprotein in individual cells. The P-Glycoprotein was found on the surface of cells of gastric areas with intestinal metaplasia subtype III. This type of intestinal metaplasia, also called “colonic metaplasia”, has been strongly associated with a high risk for the development of gastric cancer. The fact that the P-Glycoprotein was detected in this precursor lesion is consistent with the intestinal metaplasia dysplasia and carcinoma sequence proposed in the histogenesis of this tumor. The finding that P-Glycoprotein was heterogeneously expressed in malignant cells of some gastric adenocarcinomas also suggests that this transporter system probably contributes to primary and secondary multidrug resistance in this neoplasm.     

Study of hypothalamic leptin receptor expression in low-birth-weight piglets and effects of leptin supplementation on neonatal growth and development

Low birth weight resulting from intrauterine growth retardation (IUGR) is a risk factor for further development of metabolic diseases. The pig appears to reproduce nearly all of the phenotypic pathological consequences of human IUGR and is likely to be more relevant than rodents in studies of neonatal development. In the present work, we characterized the model of low-birth-weight piglets with particular attention to the hypothalamic leptin-sensitive system, and we tested whether postnatal leptin supplementation can reverse the precocious signs of adverse metabolic programming. Our results demonstrated that 1) IUGR piglets present altered postnatal growth and increased adiposity; 2) IUGR piglets exhibit abnormal hypothalamic distribution of leptin receptors that may be linked to further disturbance in food-intake behavior; and 3) postnatal leptin administration can partially reverse the IUGR phenotype by correcting growth rate, body composition, and development of several organs involved in metabolic regulation. We conclude that IUGR may be characterized by altered leptin receptor distribution within the hypothalamic structures involved in metabolic regulation and that leptin supplementation can partially reverse the IUGR phenotype. These results open interesting therapeutic perspectives in physiopathology for the correction of defects observed in IUGR.     

Leptin expression and leptin receptor gene polymorphisms in growth hormone deficiency patients

Growth hormone deficiency (GHD) patients have lower weight, height, bone age, insulin-like growth factor 1 (IGF-1) levels, GH levels, fat metabolism and skeletal growth. The association of leptin with GHD characteristics and the effect of gene variants of leptin on GHD are unknown. Our aim was to examine the association of circulating leptin levels and common genetic variants in leptin (LEP) and leptin receptor (LEPR) genes with anthropometric measures, circulating hormone concentrations and GHD. A case control study of 125 GHD cases and 159 control subjects were characterized for bone age, body mass index (BMI), height, weight, leptin, IGF-1, GH and their genotype at the leptin promoter G-2548A, and LEPR variants, K109R and Q223R, at Chung Shan Medical University Hospital. Leptin levels were significantly associated with lower bone age, weight and BMI in GHD patients. Leptin levels were also significantly associated with reduced IGF-1 levels in girls but not boys in both groups. The frequency of LEPR223 [A/G or A/A] genotype was significantly higher than the LEPR223 G/G genotype in the GHD group. The LEPR223 [A/G or A/A] genotype was significantly associated with increased weight and BMI in the control group, but not in the GHD group. In conclusion, the GHD group carried a significantly higher frequency of the LEPR [G/A or A/A] genotype and of the A allele (LEPR223R). The LEPR223R polymorphism affected weight and BMI in control, but not in GHD patients, suggesting that the effect of LEPR223 [A/G or A/A] genotype was counteracted by other factor(s) in GHD patients.     

Intratumoral expression of IL-17 and its prognostic role in gastric adenocarcinoma patients

In this study, we characterized the intratumoral expression of IL-17 and CD8(+) TILs in gastric adenocarcinoma patients after resection and determined the correlation between the survival probability of gastric adenocarcinoma patients and the expression of IL-17 in tumor. Expression of IL-17 and CD8 was assessed by immunohistochemistry, and the prognostic effects of intratumoral IL-17 expression and CD8(+) TILs were evaluated by Cox regression and Kaplan-Meier analysis. Immunohistochemical detection revealed the presence of IL-17 and CD8(+) cells in gastric adenocarcinoma tissue samples (90.6%, 174 out of 192 patients and 96.9%, 186 out of 192 patients, respectively). We have also found that intratumoral IL-17 expression was significantly correlated with age (p=0.004) and that the number of CD8(+)TILs was significantly correlated with UICC staging (p=0.012) and the depth of tumor invasion (p=0.022). The five-year overall survival probability among patients intratumorally expressing higher levels of IL-17 was significantly better than those expressing lower levels of IL-17 (p=0.036). Multivariate Cox proportional hazard analyses revealed that intratumoral IL-17 expression (HR: 0.521; 95% CI: 0.329-0.823; p=0.005) was an independent factor affecting the five-year overall survival probability. We conclude that low levels of intratumoral IL-17 expression may indicate poor prognosis in gastric adenocarcinoma patients.     

Multidrug resistance gene and P-glycoprotein expression in gastric adenocarcinoma and precursor lesions.

Overexpression of the Multiple Drug Resistance gene (MDR1) has been proposed as a major mechanism related to both intrinsic and acquired resistance to chemotherapeutic agents. The gene product is a membrane protein (P-glycoprotein), that acts as an energy-dependent drug efflux pump decreasing drug accumulation in resistant tumor cells. We have characterized MDR1 and P-Glycoprotein expression in human gastric adenocarcinoma and in precursor lesions. MDR1 mRNAs, analyzed by dot-blot technique, were detected in 9 of 10 non-tumoral gastric mucosae and in 8 of 10 gastric adenocarcinomas. Immunohistochemical analysis, using the MRK16 monoclonal antibody, revealed heterogeneous expression of P-Glycoprotein in individual cells. The P-Glycoprotein was found on the surface of cells of gastric areas with intestinal metaplasia subtype III. This type of intestinal metaplasia, also called "colonic metaplasia", has been strongly associated with a high risk for the development of gastric cancer. The fact that the P-Glycoprotein was detected in this precursor lesion is consistent with the intestinal metaplasia-dysplasia and carcinoma sequence proposed in the histogenesis of this tumour. The finding that P-Glycoprotein was heterogeneously expressed in malignant cells of some gastric adenocarcinomas also suggests that this transporter system probably contributes to primary and secondary multidrug resistance in this neoplasm.     

Endogenous microRNA can be broadly exploited to regulate transgene expression according to tissue, lineage and differentiation state

We have shown previously that transgene expression can be suppressed in hematopoietic cells using vectors that are responsive to microRNA (miRNA) regulation. Here we investigate the potential of this approach for more sophisticated control of transgene expression. Analysis of the relationship between miRNA expression levels and target mRNA suppression suggested that suppression depends on a threshold miRNA concentration. Using this information, we generated vectors that rapidly adjust transgene expression in response to changes in miRNA expression. These vectors sharply segregated transgene expression between closely related states of therapeutically relevant cells, including dendritic cells, hematopoietic and embryonic stem cells, and their progeny, allowing positive/negative selection according to the cells' differentiation state. Moreover, two miRNA target sites were combined to restrict transgene expression to a specific cell type in the liver. Notably, the vectors did not detectably perturb endogenous miRNA expression or regulation of natural targets. The properties of miRNA-regulated vectors should allow for safer and more effective therapeutic applications.     

Changes of Golgi complex during the induced differentiation of human gastric adenocarcinoma cells in vitro

Golgi complex is a central link related to each kind of organella in cellular metabolic process, its morphological changes are often concerned with the cell differentiation and functional state. The Golgi complexes in tumour cells have the characteristics of poor development and non-typical structure, and closely related to their pathological differential degree. For this reason, having based on appraising the differential effect of human gastric adenocarcinoma cell line MGc 80-3 induced by dBcAMP in vitro, we had made a systematic observation on the changes of Golgi complex during the malignant phenotypical reversion of MGc 80-3 cells, in order to inquire into the relationship between the structural and functional changes of Golgi complex and the malignant phenotypic reversion of cancer cells. It was revealed by ultrathin sectioning and freeze-etching electron microscopy that, in MGc 80-3 cells, there were a few Golgi complexes, their volume was small, the amounts of saccule were few, they arranged irregularly, expanded and inflated, and the intramembranous particles on saccule were rare and not well-distributed. It displayed a non-developmental and non-typical structural state of Golgi complex. But after induced treatment with dBcAMP, the Golgi complexes had grown in number and distributed concentrated, , their volume enlarged, the saccules increased and arranged regularly, and the intermembranous particles on saccules were plentiful and well-distributed. They had restored a well-developed and typical structure of Golgi complex similar to that of the primary culture cell of human normal gastric mucous membrane. It showed that Golgi complex had further changed into a quite developed state during the induced differentiation. This alteration not only inhibited the malignant secretory activity of gastric carcinoma cells but also played a certain regulative role in the changes of the surface components of cancer cells. The structural and functional changes of Golgi complex were considered to be an important expression in the malignant phenotypical reversion of cancer cells, it had an important influence on the differentiation of cancer cells from malignant to normal direction.