The p53 codon 72 polymorphism in Thai nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a serious cancer in Thailand. To address on the genetic risk factor for NPC, we investigated association between the p53 codon 72 polymorphism (Pro/Arg) and NPC susceptibility in the Thai. The genotype frequency of this polymorphism in 102 NPC patients and 148 age-matched healthy controls was determined by using a PCR-RFLP assay. No statistically significant difference in the overall genotype frequencies or allele frequencies between cases and controls was observed. Among NPC patients, no statistical significant difference in p53 genotype frequencies between sex, histological types and clinical stages was observed. When cases and controls were categorized into 3 groups of age, >40, >45 and >50 years, the frequencies of p53 genotype in the cases were significantly different from those of the controls (P<0.05). The p53 Pro homozygotes with age of >40 years had twofold to threefold higher risk to develop NPC and the risk was increased with age (Odds Ratio (OR) increased from 2.01 to 2.63 by age >40 to >50 years). Individuals of age >40, >45 and >50 years with an Arg/Arg genotype and of age >45 and >50 years with combined Arg/Arg or Arg/Pro genotype had lower risk to develop NPC than those with Pro/Pro genotype (P<0.05). Collectively, we suggest that the p53 gene polymorphism may associate with NPC susceptibility in Thai population, particularly the Pro/Pro genotype carriers with age of >40 years. The detection of this p53 polymorphism may be a useful tool for screening of early stage and diagnosis of NPC.

A novel sensitive high-performance liquid chromatography/electrochemical procedure for measuring formaldehyde produced from oxidative deamination of methylamine and in biological samples

Formaldehyde is a well-known environmental toxic hazard. It is also a product of oxidative deamination of methylamine catalyzed by semicarbazide-sensitive amine oxidase (SSAO). Increased SSAO-mediated deamination has been implicated in some pathophysiological conditions, such as diabetic complications. The measurement of formaldehyde in the enzymatic reactions and in vivo production using conventional methods was not straightforward due to limitations of selectivity and sensitivity. A novel high-performance liquid chromatography (HPLC)/electrochemical procedure for the measurement of formaldehyde has been developed. The measurement is based on the formation of adducts between formaldehyde and dopamine. These adducts can be selectively purified and concentrated using a batch method of alumina absorption, separated by HPLC, and electrochemically quantified. The method is highly selective and substantially more sensitive, i.e., detection of picomole levels of formaldehyde, than the conventional methods. The procedure not only facilitates the assessment of SSAO activity in vitro but also is useful for assessing formaldehyde in tissues and biological fluids.

Expression of survivin in human gastric carcinoma and gastric carcinoma model of rats

AIM: To study the expression of survivin, an inhibitor of apoptosis protein, in human gastric carcinomas and gastric carcinoma models of rats.

METHODS: With the method of immunohistochemical staining, we studied the expression of survivin in 20 cases of chronic gastritis and 56 cases of gastric carcinomas. We used N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and high dose sodium-chloride diet to induce rat gastric carcinomas. Survivin expression was studied in glandular stomachs of normal rats, adenocarcinomas and tissues adjacent to the tumor, as well as in rats during the induction period.

RESULTS: Survivin was expressed in 27 of 56 (48.2%) cases of human gastric carcinoma tissues and 1 of 20 (5%) cases of chronic gastritis. It was found that the expression of survivin had no relation with the elements of age, tumor depth, tumor size, and disease stage, but was significantly related to histological type. The positive rate of survivin expression in cases of intestinal type was significantly higher than that in cases of diffuse type (P < 0.05). In animal experiments, survivin expression in glandular stomachs of normal rats, of rats in middle induction period, in adenocarcinomas and tissues adjacent to tumor were 0, 40.0%, 78.3% and 38.9%, respectively. Compared with the survivin expression in normal rats, the differences were significant.

CONCLUSION: These data imply that survivin plays an important role in the onset of gastric carcinoma and that high survivin expression is an early event of gastric carcinoma.

Spiral CT in gastric carcinoma: Comparison with barium study, fiberoptic gastroscopy and histopathology

AIM: To evaluate spiral computed tomography (CT) including virtual gastroscopy for diagnosis of gastric carcinoma in comparison with upper gastrointestinal series (UGI), fiberoptic gastroscopy (FG) and histopathology.

METHODS: Sixty patients with histologically proven gastric carcinoma (54 advanced and 6 early) were included in this study. The results of spiral CT were compared with those of UGI and FG. Two observers blindly evaluated images of spiral CT and UGI and video recording of FG with consensus in terms of diagnostic confidence with a five-point scale. Sensitivities of lesion detection, Borrmann's classification of spiral CT, UGI and FG, as well as the accuracy of TNM staging of spiral CT were determined by comparing them to surgical and histological findings.

RESULTS: The lesion detection rate was 98% (59/60), 95% (57/60) and 98% (59/60) for spiral CT, UGI and FG, respectively. There were no statistical differences in the detection sensitivity among the three techniques (P > 0.05). For the sensitivity in Borrmann's classification, spiral CT was higher than that of UGI (P = 0.025) and similar to that of FG (P > 0.05). The accuracy of spiral CT in staging the gastric carcinoma was 76.7%. Six cases of early gastric carcinoma were all detected by spiral CT as well as FG.

CONCLUSION: Spiral CT is equivalent to UGI and FG in the detection of gastric carcinoma, and superior to UGI but similar to FG in the Borrmann's classification of advanced gastric carcinoma. Spiral CT is more valuable than FG in the staging of gastric carcinoma.

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Epidemiology of alcoholic liver diseases in Xi'an

AIM

To investigate the characteristics of ethanol consumption in Xi'an area, and to explore the prevalence of alcoholic liver disease and the correlation of the quantity of ethanol consumed with the development of alcoholic liver disease.

METHODS

By random cluster sampling, 9 professional groups of people were chosen in the city and the rural areas as subjects. Questionaire was taken and the data collected and analyzed by specialists.

RESULTS

During April to June 2000, 3 613 persons were investigated. Among them 1270 were drinkers, in which 90.1% were males and only 126 females. 78 persons were alcoholic fatty liver patients (6.1%). The prevalence rate was 2.2% in all subjects. Only one female patient with alcoholic liver disease (0.3%), and 5 cases of alcoholic cirrhosis (0.1%) were found. Alcoholic fatty liver patients consumed the equivalent of 31.3+24.2 g absolute ethanol with a mean duration of 14.0+7.4 years. With increase of alcoholic consumption the serum levels of ALT and AST increased. The prevalence rate of alcoholic fatty liver is higher in city than that in rural area.

CONCLUSION

Alcohol drinkers in Xi'an are very popular. Males are the major population. Alcoholic fatty liver is the most common type of ALD with prevalence rate of 2.2%. The equivalent of 30 g ethanol consumed in more than 14 years may result in alcoholic fatty liver. The alterations of liver function are parallel to the consumption of alcohol.

Detection of human papillomavirus in Chinese esophageal squamous cell carcinoma and its adjacent normal epithelium

AIM: To investigate the putative role of human papillomavirus (HPV) infection in the carcinogenesis of esophageal squamous cell carcinoma in China.

METHODS: Twenty-three esophageal squamous cell carcinoma samples and the distal normal epithelium from Shanxi Province, and 25 more esophageal squamous cell carcinoma samples from Anyang city, two areas with a high incidence of esophageal cancer in China, were detected for the existence of HPV-16 DNA by PCR, mRNA in situ hybridization (ISH) and immunohistochemistry (IHC) targeting HPV-16 E6 gene.

RESULTS: There were approximately 64% (31/48) patients having HPV-16 DNA in tumor samples, among them nearly two-thirds (19/31) samples were detected with mRNA expression of HPV-16 E6. However, in the normal esophageal epithelium from cancer patients, the DNA and mRNA of HPV-16 were found with much less rate: 34.7% (8/23) and 26.1% (6/23) respectively. In addition, at protein level detected by IHC assay, 27.1% (13/48) tumor samples had virus oncoprotein E6 expression, while only one case of normal epithelium was found positive.

CONCLUSION: HPV infection, especially type 16, should be considered as a risk factor for esophageal malignancies in China.

NF-κB activation and zinc finger protein A20 expression in mature dendritic cells derived from liver allografts undergoing acute rejection

AIM: To investigate the role of NF-κB activation and zinc finger protein A20 expression in the regulation of maturation of dendritic cells (DCs) derived from liver allografts undergoing acute rejection.

METHODS: Sixty donor male SD rats and sixty recipient male LEW rats weighing 220-300 g were randomly divided into whole liver transplantation group and partial liver transplantation group. Allogeneic (SD rat to LEW rat) whole and 50% partial liver transplantation were performed. DCs from liver grafts 0 hour and 4 d after transplantation were isolated and propagated in the presence of GM-CSF in vitro. Morphological characteristics and phenotypical features of DCs propagated for 10 d were analyzed by electron microscopy and flow cytometry, respectively. NF-κB binding activity, IL-12 p70 protein and zinc finger protein A20 expression in these DCs were measured by EMSA and Western blotting, respectively. Histological grading of rejection was determined.

RESULTS: Allogeneic whole liver grafts showed no signs of rejection on day 4 after the transplantation. In contrast, allogeneic partial liver grafts demonstrated moderate to severe rejection on day 4 after the transplantation. After propagation for 10 d in the presence of GM-CSF in vitro, DCs from allogeneic whole liver grafts exhibited features of immature DC with absence of CD40 surface expression, these DCs were found to exhibit detectable but very low level of NF-κB activity, IL-12 p70 protein and zinc finger protein A20 expression. Whereas, DCs from allogeneic partial liver graft 4 d after transplantation displayed features of mature DC, with high level of CD40 surface expression, and as a consequence, higher expression of IL-12p70 protein, higher activities of NF-κB and higher expression of zinc finger protein A20 compared with those of DCs from whole liver grafts (P < 0.001).

CONCLUSION: These results suggest that A20 expression is up-regulated in response to NF-κB activation in mature DCs derived from allogeneic liver grafts undergoing acute rejection. Given the NF-κB inhibition function of this gene, it is suggested that their expression survives to limit NF-κB activation and maturation of DCs, and consequently inhibits the acute rejection and induces acceptance of liver graft.

Upregulated expression of Ezrin and invasive phenotype in malignantly transformed esophageal epithelial cells

AIM: To investigate the correlation between ezrin expression and invasive phenotype formation in malignantly transformed esophageal epithelial cells.

METHODS: The experimental cell line employed in the present study was originated form the progressive induction of a human embryonic esophageal epithelial cell line (SHEE) by the E6E7 genes of human papillomavirus (HPV) type 18. The cells at the 35^th passage after induction called SHEEIMM were in a state of immortalized phase and used as the control, while that of the 85^th passage denominated as SHEEMT represented the status of cells that were malignantly transformed. The expression changes of ezrin and its mRNA in both cell passages were respectively analyzed by RT-PCR and Western blot. Invasive phenotype was assessed in vivo by inoculating these cells into the severe combined immunodeficient (SCID) mice via subcutaneous and intraperitoneal injection, and in vitro by inoculating them on the surface of the amnion membranes, which then was determined by light microscopy and scanning electron microscopy.

RESULTS: Upregulated expression of ezrin protein and its mRNA was observed in SHEEMT compared with that in SHEEIMM cells. The SHEEMT cells inoculated in SCID mice were observed forming tumor masses in both visceral organs and soft tissues in a period of 40 d with a special propensity to invading mesentery and pancreas, but did not exhibit hepatic metastases. Pathologically, these tumor cells harboring larger nucleus, nucleolus and less cytoplasm could infiltrate and destroy adjacent tissues. In the in vitro study, the inoculated SHEEMT cells could grow in cluster on the amniotic epithelial surface and intrude into the amniotic stroma. In contrast, unrestricted growth and invasiveness were not found in SHEEIMM cells in both in vivo and in vitro experiment.

CONCLUSION: The upregulated ezrin expression is one of the important factors that are possibly associated with the invasive phenotype formation in malignantly transformed esophageal epithelial cells.

Research and control of well water pollution in high esophageal cancer areas

AIM: In order to detect risk factors for esophageal cancer, a national research program was carried out during the Eighth Five-Year Plan (from 1991 to 1995).

METHODS: Cixian County and Chichen County in Hebei Province were selected as the index and the control for the study fields with higher or lower incidence of esophagus cancer in China, respectively. In these areas, we investigated the pollution of three nitrogenous compounds in well water for drinking and the use of nitrogen fertilizer in farming.

RESULTS: In well water, nitrate nitrogen, nitrite nitrogen and ammonia nitrogen were 8.77 mg/L, 0.014 mg/L and 0.009 mg/L in Cixian County in 1993, respectively. They were significantly higher than their levels (3.84 mg/L, 0.004 mg/L and 0.004 mg/L) in Chichen County (P < 0.01, t = 6.281, t = 3.784, t = 3.775). There was a trend that the nitrogenous compounds in well water increased from 1993 to 1996. The amount of nitrogen fertilizer used in farming was 787.6 kg per hectare land in Cixian County in 1991, significantly higher than 186 kg per hectare in Chichen County (t = 9.603, P < 0.001).

CONCLUSION: These investigations indicate that the pollution of nitrogenous compounds in well water for drinking is closely related to the use of nitrogen fertilizer in farming, and there is a significantly positive correlation between the level of three nitrogenous compounds in well water and the mortality of esophageal cancer (correlation coefficient = 0.5992). We suggest that improvement of well system for drinking water quality should be an effective measure for esophageal cancer prevention and control in rural areas.

In vivo antitumour activity of PBMCs via genetic modification of single-chain immunotoxin

AIM

To investigate In vivo antitumour activity of single-chain immunotoxin (sFv-TNF-α fusion protein).

METHODS

HCC-specific killer cells were generated by transducing the recombinant retroviral virus in supernatant of the virus producing cells (C₂₂) into human peripheral blood mononuclear cells (PBMCs). SMMC-7721 xenograft nude mice were given iv either 1×10⁶ (0.2 mL) transduced or mock-transduced PBMCs once five days for three weeks and tumour growth was detected.

RESULTS

Tumour growth were (20.8±4.9) mg/d in PBMCs/PST group and (28.5±6.7)mg/d in PBMCs/ pLXSN group, with a significant difference (P<0.05).

CONCLUSION

Genetic modification of PBMCs by single-chain immunotoxin has antitumour activity In vivo.

Protective effect of dietary nitrate on experimental gastritis in rats

Nitrates have long been considered as harmful dietary components and judged responsible for deleterious effects on human health, leading to stringent regulations concerning their levels in food and water. However, recent studies demonstrate that dietary nitrate may have a major role in human health as a non-immune mechanism for host defence, through its metabolism to NO in the stomach. NO is a versatile molecule and although evidence exists showing that administration of low doses of exogenous NO protects against gastrointestinal inflammation, higher NO doses have been shown to exacerbate injury. So, the effect of an ingestion of nitrates in doses corresponding to a normal diet in human consumers on an experimental gastritis induced by iodoacetamide in rats was investigated. During gastritis one of the following compounds was given orally: water; KNO3; the NO donor sodium nitroprusside; the NO scavenger haemoglobin given with either water or KNO3. N(G)-nitro-l-arginine methyl ester (l-NAME), a non-specific NO synthase inhibitor, was administered with either water, iodoacetamide alone, or combined with KNO3. After killing, the stomach was resected and microscopic damage scores, myeloperoxidase and NO synthase activities were determined. Iodoacetamide-induced gastritis was significantly reduced by KNO3 administration, an effect which was reproduced by sodium nitroprusside and reversed by haemoglobin. l-NAME induced gastric mucosal damage in itself, and KNO3 did not prevent the gastritis induced by iodoacetamide associated with l-NAME. In conclusion, dietary nitrate exerts a protective effect against an experimental gastritis in rats by releasing NO in the stomach but such an effect requires the production of endogenous NO.

Bulbinelonesides A-E, phenylanthraquinone glycosides from the roots of Bulbinella floribunda

The roots of Bulbinella floribunda have been analyzed for the phenolic constituents, resulting in the isolation of five new phenylanthraquinone glycosides, named bulbinelonesides A-E (1-5), along with two known phenylanthraquinones, (+)-M-knipholone (6) and (+)-M-isoknipholone (7). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of enzymatic hydrolysis. Although the new compounds 3-5, whose absolute stereochemistry of the unsymmetric biaryl moiety was determined to be P by the CD spectrum, did not show apparent cytotoxicity against cultured HSC-2 tumor cells and HPC normal cells, the new compounds 1 and 2, as well as the known compounds 6 and 7, whose biaryl bond was assigned as M, exhibited a tumor-specific cytotoxicity against HSC-2 cells comparable to or slightly weaker than etoposide, used as a positive control.

Inhibitory effect of p27kip1 mediated by adenovirus on model of esophageal carcinoma in nude mice

AIM

To investigate the inhibitory effect of p27kip1 mediated by adenovirus vector on esophageal carcinoma in vivo.

METHODS

Eca109 cells were injected into the subcutaneous tissue of nude mice to establish tumors. The transplanted tumors were reproduced among the nude mice contionually after original grafts grew well. The model of esophageal carcinoma in nude mice was established by transplanting the tumor tissue mass into the subcutaneous tissue of nude mice .The successful constructed recombinant adenoviral vector carrying p27kip1 gene and LacZ recombinant adenovirus were directly injected into the esophageal tumors in nude mice respectively. Compared with control group, the growth curves of tumor were drawed and the growth inhibition rates of tumor were calculated.

RESULTS

The growth of tumors in gene therapy group with p27kip1 was obviously suppressed, which had a significant difference compared with control group (P < 0.001). The growth inhibition rate of tumor reached 64.1%.

CONCLUSION

p27kip1 gene therapy mediated by adenovirus vector has significant inhibitory effect on esophageal carcinoma in vivo.

Preventive effect of zaprinast and 3-isobutyl, 1-methylxanthine (phosphodiesterase inhibitors) on gastric injury induced by nonsteroidal antiinflammatory drugs in rats

Cyclic GMP plays an important role in maintaining homeostasis in the gastric mucosa. NSAIDs damage the mucosa by mechanisms that may be mediated by alterations in the intragastric concentration of cyclic GMP. To test this hypothesis we studied the effects of the oral administration of acetylsalicylic acid (100, 300, and 500 mg/kg), piroxicam (5, 10, and 20 mg/kg) and sodium diclofenac (10, 25, 50, and 100 mg/kg), and of their interaction with zaprinast (5 mg/kg) and IBMX (10 mg/kg), on intragastric concentrations of cyclic GMP and the gastric erosive index in rats. All determinations were done 3 hr after the NSAID was given. All NSAIDs induced dose-dependent decreases in mucosal concentrations of cyclic GMP, which correlated inversely with the surface area showing mucosal injury. In contrast, cyclic GMP concentrations remained normal, and no intragastric damage was seen in rats given zaprinast (cyclic GMP-specific phosphodiesterase inhibitor) or IBMX (non-specific phosphodiesterase inhibitor) or in combination with NSAIDs. These findings are in line with the hypothesis that cyclic GMP is involved in the biochemical mechanisms of NSAID-induced gastric injury.

Loss of clusterin both in serum and tissue correlates with the tumorigenesis of esophageal squamous cell carcinoma via proteomics approaches

AIM: To identify the differentially secreted proteins or polypeptides associated with tumorigenesis of esophageal squamous cell carcinoma (ESCC) from serum and to find potential tumor secreted biomarkers.

METHODS: Proteins from human ESCC tissue and its matched adjacent normal tissue; pre-surgery and post-surgery serum; and pre-surgery and normal control serum were separated by two-dimensional electrophoresis (2-DE) to identify differentially expressed proteins. The silver-stained 2-DE were scanned with digital ImageScanner and analyzed with ImageMaster 2D Elite 3.10 software. A cluster of protein spots differentially expressed were selected and identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). One of the differentially expressed proteins, clusterin, was down-regulated in cancer tissue and pre-surgery serum, but it was reversed in post-surgery serum. The results were confirmed by semi-quantitative reverse-transcription (RT)-PCR and western blot.

RESULTS: Comparisons of the protein spots identified on the 2-DE maps from human matched sera showed that some proteins were differentially expressed, with most of them showing no differences in composition, shape or density. Being analyzed by MALDI-TOF-MS and database searching, clusterin was differentially expressed and down-regulated in both cancer tissue and pre-surgery serum compared with their counterparts. The results were also validated by RT-PCR and western blot.

CONCLUSION: The differentially expressed clusterin may play a key role during tumorigenesis of ESCC. The 2DE-MS based proteomic approach is one of the powerful tools for discovery of secreted markers from peripheral.

Expression of estrogen receptor and estrogen receptor messenger RNA in gastric carcinoma tissues

AIM: To study estrogen receptor (ER) and estrogen receptor messenger RNA (ERmRNA) expression in gastric carcinoma tissues and to investigate their association with the pathologic types of gastric carcinoma.

METHODS: The expression of ER and ERmRNA in gastric carcinoma tissues (15 males and 15 females, 42-70 years old) was detected by immunohistochemistry and in situ hybridization, respectively.

RESULTS: The positive rate of ER (immunohistochemistry) was 33.3% in males and 46.7% in females. In Borrmann IV gastric carcinoma ER positive rate was greater than that in other pathologic types, and in poorly differentiated adenocarcinoma and signet ring cell carcinoma the positive rates were greater than those in other histological types of both males and females (P < 0.05). The ER was more highly expressed in diffused gastric carcinoma than in non-diffused gastric carcinoma (P < 0.05). The ER positive rate was also related to regional lymph nodes metastases (P < 0.05), and was significantly higher in females above 55 years old, and higher in males under 55 years old (P < 0.05). The ERmRNA (in situ hybridization) positive rate was 73.3% in males and 86.7% in females. The ERmRNA positive rates were almost the same in Borrmann I, II, III and IV gastric carcinoma (P > 0.05). ERmRNA was expressed in all tubular adenocarcinoma, poorly differentiated adenocarcinoma and signet ring cell carcinoma (P < 0.05). The ERmRNA positive rate was related to both regional lymph nodes metastases and gastric carcinoma growth patterns, and was higher in both sexes above 55 years old but without statistical significance (P > 0.05). The positive rate of ERmRNA expression by in situ hybridization was higher than that of ER expression by immunohistochemistry (P < 0.05).

CONCLUSION: ERmRNA expression is related to the pathological behaviors of gastric carcinoma, which might help to predict the prognosis and predict the effectiveness of endocrine therapy for gastric carcinoma.

Comparison of therapeutic efficacy between tumor-derived heat shock protein 70 and interleukine-2

AIM

To compare and analyze the therapeutic effect of tumor-derived heat shock protein 70 and globally accepted interleukin-2, to evaluate the anti-tumor capacity of HSP70, and to provide significant information for HSP70 administration to treat human cancers.

METHODS

Cell Culture, techniques for protein extraction and purification, SDS-PAGE, Western-blot and animal experiment were used in this study.

RESULTS

Both IL-2 and HSP70 showed therapeutic effect in tumor-bearing mice. The best effect was observed in 100 000 U IL-2 and 10 μg HSP70 administrations, and partial efficacy was found in 50000 U IL-2 and 5 μg HSP70 administrations. The effect of 100000 U IL-2 was nearly as good as that of 5 μg HSP70. About 40 % mice receiving HSP70 10 μg administration survived over 90 days, the average survival period of this group was over 56.8 days, whereas the control group was 17.3 days, IL-2 50 000 group, 26.3 days, IL-2 100 000 group, 36.6 days, and 5 μg HSP70 group, 27.7 days. Significant difference was found (P<0.05) when compared with the HSP70 10 μg group and control group.

CONCLUSION

HSP70 has a specific anti-tumor effect and obviously exceeded IL-2 .Those data provide significant information for the treatment of human cancers.

Expression of survivin protein in hepatocellular carcinoma tissues and its relationship with clinical pathological features and prognosis

AIM

To investigate the expression of survivin protein in human hepatocellular carcinoma (HCC) and its relationship with clinical features and prognosis of patients with HCC.

METHODS

The expression of survivin protein and the proliferation of tumor cells marked by PCNA in 48 cases of HCC were assessed by immunohistochemical method. TUNEL method was used to detect apoptosis.

RESULTS

The survivin protein was expressed in 31 of 48 cases of HCC (64.6%). Expression of survivin protein was significantly higher in those of Edmondson grade Ⅲ-Ⅳ than in those of grade Ⅰ-Ⅱ (88.0% vs 39.1%, P = 0.013). The ratio of proliferative index to apoptotic index was significantly higher in HCC with positive survivin expression than that with negative survivin expression (1.8 vs 1.1, P = 0.045). The survival rate of three years of patients with positive survivin expression was significantly lower than that of patients with negative survivin expression (70.6% vs 35.5%, P = 0.011).

CONCLUSION

The expression of survivin may play an important role in breaking the balance of proliferation and apoptosis of HCC cells and is closely associated with prognosis of patients with HCC.

Detection of LMP-1 gene in middle ear effusion of NPC

Nasopharyngeal carcinoma (NPC) is closely related with Epstein-Barr virus (EBV). Almost every NPC tumor cells carries clonal EBV genomes. Detection of EBV derived latent membrane protein-1 gene (LMP-1) indicate the presence of NPC. Middle ear effusion (MEE) is a frequent sign of NPC. There have been no reports on LMP-1 in MEE. Tympanocentesis of 88 ears with MEE of 66 patients were done in three groups of patients, group (I) NPC, 31 patients, 50 ears, (II) other head and neck cancers, five patients, six ears and (III) no cancer history, 30 patients, 32 ears. The middle ear aspirate and nasopharyngeal swab specimen were collected to detect LMP-1 with a PCR-based method. Sixty aspirates (68%) out of 88 ears with MEE had enough DNA for PCR amplification. LMP-1 was detected in six middle ear aspirate specimen from three patients in group I who had petrous apex invasion. LMP-1 was detected in 30 swab specimen (93.8%) out of 32 nasopharyngeal swabs in group I. LMP-1 was not detected in middle ear aspirates or nasopharyngeal swab in group II and III patients. LMP-1 was not detected in MEE in patients without NPC. In NPC patients, the detection of LMP-1 may indicate petrous apex invasion.

Cation-chloride co-transporters in neuronal communication, development and trauma

Electrical signaling in neurons is based on the operation of plasmalemmal ion pumps and carriers that establish transmembrane ion gradients, and on the operation of ion channels that generate current and voltage responses by dissipating these gradients. Although both voltage- and ligand-gated channels are being extensively studied, the central role of ion pumps and carriers is largely ignored in current neuroscience. Such an information gap is particularly evident with regard to neuronal Cl- regulation, despite its immense importance in the generation of inhibitory synaptic responses by GABA- and glycine-gated anion channels. The cation-chloride co-transporters (CCCs) have been identified as important regulators of neuronal Cl- concentration, and recent work indicates that CCCs play a key role in shaping GABA- and glycine-mediated signaling, influencing not only fast cell-to-cell communication but also various aspects of neuronal development, plasticity and trauma.

Regulation of the H19 imprinting gene expression in human nasopharyngeal carcinoma by methylation

In East Asia and Singapore, the human nasopharyngeal carcinoma (NPC) presented clinically is mainly of the undifferentiated type. In contrast, the well-differentiated squamous NPC is more commonly detected in the West. To study the potential differences in carcinogenesis between undifferentiated and differentiated human NPC, we employed cDNA microarrays to isolate genes that might be specific for human undifferentiated NPC. One of the genes identified to be specifically upregulated in the undifferentiated human NPC cell line CNE-2 is the human imprinting gene H19. Interestingly, H19 is not expressed in the well-differentiated human HK1 NPC cells. Northern blot and in situ hybridization analyses also confirmed that the H19 gene is strongly expressed in the undifferentiated CNE-2 human NPC cell line but not in the well-differentiated HK1 human NPC cell line. In situ hybridization and reverse transcriptase-polymerase chain reaction also demonstrated that H19 is specifically expressed in NPC biopsies and not in non-NPC human tissue biopsies. Furthermore, we demonstrated that deregulation of H19 gene expression in the well-differentiated human HK1 NPC cells could be induced by the hypomethylation of CpG sites of the H19 promoter region. Hypermethylation of gene promoter regions might therefore be an important epigenetic event that plays a role in the differentiation of human NPC cells and the transcriptional silencing of imprinted genes.

Effect of expression of interferon-g gene in inhibition of growth of colon cancer cell

AIM: To investigate the effect of expression of interferon-γ(IFN-γ) in tumor cell and its inhibitory effect on the growth of tumor cell.

METHODS: pcDNA3-IFN-γ vector containing IFN- γ gene was constructed and transfected into LOVO, SW620, HCT116BG and Hela cell lines by lipofectamine, respectively. The expression of IFN-γ, CEA and HLA-DR in transfected cells were tested. Both the number of apoptosis of and the proportion of cell cycles of tumor cells were measured to investigate the anti-tumor effect of IFN-γ gene therapy.

RESULTS: LOVO and HCT116BG transfected cell lines had high expression of CEA, the average level of CEA was significantly increased from 26.02±6.76 to 38.85±7.07 mg/L (P < 0.05). However, there was no detectable increase in the supernatants of Hela, SW620 cell lines that naturally expressed little of CEA. Flow cytometry analysis showed that HLA-DR expression rate (11.67±7.20) was significantly higher than that prior gene transfection (3.91±3.61) (P < 0.01), and the IFN-γ gene transfer effectively induced the apoptosis of tumor cells, the proportion of DNA synthesis phase was deceased gradually after IFN-γ gene transfer, which indicated that the synthesis of DNA and growth of tumor cells were repressed.

CONCLUSION: IFN-γ gene therapy enhanced the expression of antigens on cell surface and thus induced powerful antitumor immunity. Repressing of synthesis of DNA, inducing the apoptosis of tumor cells and inhibiting the proliferation of tumor cells might be anti-tumor mechanisms of IFN-γ.

Expression of MUC1 in esophageal squamous-cell carcinoma and its relationship with prognosis of patients from Linzhou city, a high incidence area of northern China

AIM: To further characterize the possible relationship between the molecular changes and prognosis of ESC and to elucidate the possible mechanisms involved.

METHODS: 114 specimens of ESC were collected from Linzhou city, and all patients were followed up for more than 5 years after resection. Histopathological analysis and immunohistochemical staining (ABC) were employed to detect the alteration of MUC1.

RESULTS: The positive immunostaining rate for MUC1 was 79% (90/114), and the high-expression rate was 63% (72/114). The mean survival periods (months) of those with high- and low-expression rates of MUC1 were 41 (95%CI: 35, 47) and 52 (95%CI: 45, 59), respectively. Patients in the low-expression group obviously survived longer than those in high-expression group, and the difference was significant (P < 0.05). The expression of MUC1 protein in the esophageal carcinoma specimens with metastasis was stronger than those without metastasis, the difference was also significant (P < 0.05). The stepwise multivariate analysis showed that “differentiation”, “expression of MUC1” and “TNM staging” were the most important factors affecting the prognosis of esophageal carcinoma patients (P < 0.05).

CONCLUSION: A good correlation between the alteration of MUC1 and the regional lymph node metastasis was observed. Furthermore, high-expression of MUC1 was associated with poor prognosis for esophageal cancer patients. These results indicated that MUC1 is a promising biomarker for predicting lymph node metastasis and prognosis in esophageal cancer.

Antitumor immunopreventive and immunotherapeutic effect in mice induced by hybrid vaccine of dendritic cells and hepatocarcinoma in vivo

AIM: To develop atumor vaccine by fusion of H22 hepatocarcinoma cells and DC, and to study its protective and therapeutical effect against H22 cell.

METHODS: H22-DC vaccine was produced by PEG fusion of H22 and DC induced by cytokine released from splenic mononuclear cells, sorted by CD11c magnetic microbead marker. It was injected through the tail vein of the mice and the H₂₂-DC oncogenesis was detected in the liver, spleen and lung. In order to study the therapeutical and protective effect of H₂₂-DC against tumor H₂₂, two groups were divided: immune group and therapeutic group. Immune group was further divided into P, D, HD and H subgroups, immunized by PBS, DC, H₂₂-DC and inactivated H₂₂, respectively, and attacked by H₂₂ cell. The tumor size, tumor weight, mice survival time and tumor latent period were recorded and statistically analyzed; Therapeutical group was divided into three subgroups of P, D and HD, and attacked by H₂₂, then treated with PBS, DC, and H₂₂-DC, respectively. Pathology and flow cytometry were also applied to study the mechanism how the H₂₂-DC vaccine attacked on the H₂₂ cell.

RESULTS: 1. No oncogenesis was found in spleen, lung and liver after H22-DC injection. 2. Hybrid vaccine immunized mice had strongest CTL activity. 3. In the immune group, latent period was longer in HD subgroup than that in P, H and D subgroup; and tumor size and weight were smaller in HD subgroup than that in P, H and D subgroup. 4. In therapeutic group, tumor size was smaller in HD subgroup than that in P, D subgroup.

CONCLUSION: 1. H22-DC tumor vaccine is safe without oncogenesis in vivo. 2. Hybrid vaccine can stimulate potent specific CTL activity against H22. 3. H22-DC vaccine has distinctive prophylatic effect on tumor H22 and can inhibit the tumor growth.

Application of autologous tumor cell vaccine and NDV vaccine in treatment of tumors of digestive traet

AIM: To treat patients with stage I-IV malignant tumors of digestive tract using autologous tumor cell vaccine and NDV (Newcastle disease virus) vaccine, and observe the survival period and curative effect.

METHODS: 335 patients with malignant tumors of digestive tract were treated with autologous tumor cell vaccine and NDV vaccine. The autologous tumor cell vaccine received were assigned for long-term survival observation. While these failed to obtain the autologous tumor tissue were given with NDV vaccine for a received short-term observation on curative effect.

RESULTS: The colorectal cancer patients treated with autologous tumor cell vaccine were divided into two groups: the controlled group (subjected to resection alone) (n = 257), the vaccine group (subjected to both resection and immunotherapy) (n = 310). 25 patients treated with NDV immunotherapy were all at stage IV without having resection. In postoperation adjuvant therapy patients, the 5, 6 and 7-year survival rates were 66.51%, 60.52%, 56.50% respectively; whereas in patients with resection alone, only 45.57%, 44.76% and 43.42% respectively. The average survival period was 5.13 years (resection alone group 4.15 years), the median survival period was over 7 years (resection alone group 4.46 years). There were significant differences between the two groups. The patients treated with resection plus vaccine were measured delayed-type hypersensitivity (DTH) reactions after vaccination, (indurative scope > 5 mm). The magnitude of DTH was related to the prognosis. The 5-year survival rate was 80% for those with indurations greater than 5 mm, compared with 30% for those with indurations less than 5 mm. The 1-year survival rate was 96% for 25 patients treated with NDV immunotherapy. The total effective rate (CR+PR) was 24.00% in NDV immunotherapy; complete remission (CR) in 1 case (4.00%), partial remission (PR) in 5 cases (20.00%), stabilizedin in 16 cases (64.00%), progression (PD) in 1 case (4.00%). After NDV vaccine immunotherapy, the number of NK cell increased and immune function imporved obviously.

CONCLUSION: The autologous tumor cell vaccine and NDV vaccine can prolong the patients’ life. NDV vaccine is notably effective for short-term with promotion of quality of life and can be used whenever necessary with good prospects.

HLA-DRB1 allele polymorphisms in genetic susceptibility to esophageal carcinoma

AIM: To probe into the genetic susceptibility of HLA-DRB1 alleles to esophageal carcinoma in Han Chinese in Hubei Province.

METHODS: HLA-DRB1 allele polymorphisms were typed by polymerase chain reaction with sequence-specific primers (PCR-SSP) in 42 unrelated patients with esophageal cancer and 136 unrelated normal control subjects and the associated HLA-DRB1 allele was measured by nucleotide sequence analysis with PCR.SAS software was used in statistics.

RESULTS: Allele frequency (AF) of HLA-DRB1*0901 was significantly higher in esophageal carcinoma patients than that in the normal controls (0.2500 vs 0.1397, P = 0.028, the odds ratio 2.053, etiologic fraction 0.1282). After analyzed the allele nucleotide sequence of HLA-DRB1*0901 which approachs to the corresponded exon 2 sequence of the allele in genebank. There was no association between patients and controls in the rested HLA-DRB1 alleles.

CONCLUSION: HLA-DRB1*0901 allele is more common in the patients with esophageal carcinoma than in the healthy controls, which is positively associated with the patients of Hubei Han Chinese. Individuals carrying HLA-DRB1*0901 may be susceptible to esophageal carcinoma.

An analysis of esophageal cancer incidence in Cixian county from 1974 to 1996

AIM: To describe the incidence of esophageal cancer (EC) in Cixian, a county of Hebei province during 1974-1996. We analyzed the sex and age characteristics as well as the geographic distribution of EC, in order to determine the impact so that methods of preventing and controlling EC in Cixian can be put in place.

METHODS: Since the early 1970s, the cancer registry system has been established, which collects the cancer incidence in Cixian county. The malignant tumors were coded according to International Classification of Disease IX (ICD-9). All the data were checked and analyzed using EPIINFO.

RESULTS: The trend of the incidence rate of EC from 1974 to 1996 had declined, (229.9/100000 vs 178.5/100000, Odds ratio = 1.47, 95% CI:1.32~1.63, χ² = 52.89. trend χ² = 26.54, P < 0.001). The incidence rate of males declined significantly (281.81/100000 vs 157.96/100000, Odds ratio = 1.61, 95% CI: 1.41~1.84, χ² = 47.85. Trend χ² = 44.86, P < 0.001), whereas, the females remained steady (157.96/100000 vs 133.41/100000, odds ratio = 1.28, 95% CI:1.17~1.49, χ² = 9.26. trend χ² = 2.69, P > 0.05). Male average annual incidence rate was 142.80/100000 and the female's was 95.18/100000. The sex ratio (males to females) was 1.50:1. The incidence rate was increasing along with the age. As to the geographic distribution, the incidence rate in mountainous areas and hilly areas showed a significantly declining trend (mountainous areas, trend χ² = 149.93, P < 0.001; hilly areas, trend χ² = 42.70, P < 0.001). The incidence rate of EC in plain areas had increased (trend χ² = 22.39, P < 0.001).

CONCLUSION: The incidence rate of EC in Cixian county shows a trend and has declined after two decades, especially in mountainous area. But compared to other regions in the world, Cixian county still had a high incidence rate of EC.

Preoperative TN staging of esophageal cancer: Comparison of miniprobe ultrasonography, spiral CT and MRI

AIM: To evaluate the value of miniprobe sonography (MPS), spiral CT and MR imaging (MRI) in the tumor and regional lymph node staging of esophageal cancer.

METHODS: Eight-six patients (56 men and 30 women; age range of 39-73 years, mean 62 years) with esophageal carcinoma were staged preoperatively with imaging modalities. Of them, 81 (94%) had squamous cell carcinoma, 4 (5%) adenocarcinoma, and 1 (1%) adenoacanthoma. Eleven patients (12%) had malignancy of the upper one third, 41 (48%) of the mid-esophagus and 34 (40%) of the distal one third. Forty-one were examined by spiral CT in whom 13 were co-examined by MPS, and forty-five by MRI in whom 18 were also co-examined by MPS. These imaging results were compared with the findings of the histopathologic examination for resected specimens.

RESULTS: In staging the depth of tumor growth, MPS was significantly more accurate (84%) than spiral CT and MRI (68% and 60%, respectively, P < 0.05). The specificity and sensitivity were 82% and 85% for MPS; 60% and 69% for spiral CT; and 40% and 63% for MRI, respectively. In staging regional lymph nodes, spiral CT was more accurate (78%) than MPS and MRI (71% and 64%, respectively), but the difference was not statistically significant. The specificity and sensitivity were 79% and 77% for spiral CT; 75% and 68% for MPS; and 68% and 62% for MRI, respectively.

CONCLUSION: MPS is superior to spiral CT or MRI for T staging, especially in early esophageal cancer. However, the three modalities have the similar accuracy in N staging. Spiral CT or MRI is helpful for the detection of far-distance metastasis in esophageal cancer.

Viral load of HPV in esophageal squamous cell carcinoma

We previously reported the presence of HPV DNA in esophageal squamous cell carcinoma (ESCC) cases from Hong Kong and Sichuan. The role of HPV in the carcinogenesis of ESCC remains unclear, partly due to the large variations in infection rates reported by different studies. While some of these variations may truly reflect different HPV infection rates in ESCC among different geographic regions, differences in sensitivity and specificity of the detection methods used also contribute. In the present study, we used quantitative real-time PCR to determine the copy numbers of HPV-16 and HPV-18 in ESCC from 5 different regions of China with different incidence rates of ESCC. Conforming to our previous reports, HPV infection was detected in 2-22.2% of samples. Infection with HPV-16 was again shown to be more common than that with HPV-18 among Chinese ESCC patients. The copy number of HPV-16 in these ESCC cases ranged from < or =1 to 157 copies/genome equivalent, with 65% of samples harboring fewer than 10 copies/genome equivalent. The median copy number of HPV-18 was 4.9/genome equivalent. Assays were validated using cervical carcinoma cell lines with known copy numbers of HPV-16 or HPV-18. The relatively low HPV copy number and infection rate in ESCC suggest that HPV is unlikely to play as essential a role in the carcinogenesis of ESCC as in cervical cancer. However, with the consistent detection of oncogenic HPVs in ESCC from some regions of China, the possibility of HPV infection being one of the multiple risk factors of ESCC in some geographic areas cannot be excluded.

Inhibition of Na(+)-K(+)-Cl(-) cotransporter during focal cerebral ischemia decreases edema and neuronal damage

Our previous study demonstrated that pharmacological inhibition of the Na(+)-K(+)-Cl(-) cotransporter isoform 1 (NKCC1) during ischemia and reperfusion attenuated neuronal damage and edema. In this study, we further investigated whether NKCC1 activity contributes to ischemic damage during either ischemia or reperfusion. Immunoblotting revealed that expression of NKCC1 protein was increased following 2-h focal ischemia in cerebral cortex. A sustained up-regulation of NKCC1 in cortex was detected at 4, 8, 12, and 24 h of reperfusion. An increase in the phosphorylated NKCC1 (NKCC1-p) was found at 4 and 8 h of reperfusion. In striatum, a significant increase in NKCC1 expression occurred between 4 and 24 h of reperfusion and no elevation of NKCC1-p signal was observed. Artificial cerebral spinal fluid (aCSF) or 100 microM bumetanide in aCSF were continuously microdialyzed into left cortices either 1 h prior to ischemia plus 2-h ischemia, or only during 24-h reperfusion. Infarction volume was significantly decreased in the pre-ischemic bumetanide-treated group (P<0.05) but not in the post-ischemic treatment group (P>0.05). In addition, pre-ischemic bumetanide treatment reduced the ipsilateral water content increase by 70% (P<0.05). Inhibition of NKCC1 did not attenuate poly (ADP-ribose) polymerase cleavage or the number of TUNEL-labeled apoptotic cells in ischemic brains. These results suggest that inhibition of NKCC1 attenuates cytotoxic edema and necrotic neuronal death during focal ischemia. Activation of NKCC1 activity plays a role in the early stage of ischemic damage.

Functional changes of dendritic cells derived from allogeneic partial liver graft undergoing acute rejection in rats

AIM: To investigate functional change of dendritic cells (DCs) derived from allogeneic partial liver graft undergoing acute rejection in rats.

METHODS: Allogeneic (SD rat to LEW rat) whole and 50% partial liver transplantation were performed. DCs from liver grafts 0 h and 4 d after transplantation were isolated and propagated in the presence of GM-CSF in vitro. Morphological characteristics of DCs propagated for 4 d and 10 d were observed by electron microscopy. Phenotypical features of DCs propagated for 10 d were analyzed by flow cytometry. Expression of IL-12 protein and IL-12 receptor mRNA in DCs propagated for 10 d was also measured by Western blotting and semiquantitative RT-PCR, respectively. Histological grading of rejection were determined.

RESULTS: Allogeneic whole liver grafts showed no features of rejection at day 4 after transplantation. In contrast, allogeneic partial liver grafts demonstrated moderate to severe rejection at day 4 after transplantation. DCs derived from allogeneic partial liver graft 4 d after transplantation exhibited typical morphological characteristics of DC after 4 d’ culture in the presence of GM-CSF. DCs from allogeneic whole liver graft 0 h and 4 d after transplantation did not exhibit typical morphological characteristics of DC until after 10 d’ culture in the presence of GM-CSF. After 10 d’ propagation in vitro, DCs derived from allogeneic whole liver graft exhibited features of immature DC, with absence of CD40, CD80 and CD86 surface expression, and low levels of IL-12 proteins (IL-12 p35 and IL-12 p40) and IL-12 receptor (IL-12Rβ₁ and IL-12Rβ₂) mRNA, whereas DCs from allogeneic partial liver graft 4 d after transplantation displayed features of mature DC, with high levels of CD40, CD80 and CD86 surface expression, and as a consequence, higher expression of IL-12 proteins (IL-12 p35 and IL-12 p40) and IL-12 receptors (IL-12Rβ₁ and IL-12Rβ₂) mRNA than those of DCs both from partial liver graft 0 h and whole liver graft 4 d after transplantation (P < 0.001) was observed.

CONCLUSION: DCs derived from allogeneic partial liver graft undergoing acute rejection display features of mature DC.

Glycoconjugates of the gastric mucosa in cold-treated chipmunks

During seasonal hibernation, there is reduced gastrointestinal activity, but relatively little is known of the physiology involved. In the present experimental study, male Korean chipmunks (Tamias sibiricus barberi) were maintained in cold conditions (6 degrees C) for 3, 5 or 9 months to mimic conditions occurring during seasonal hibernation. Changes in the composition of glycoconjugates (Gcs) of the gastric mucosa were determined after cold-treatment. Cold-treated chipmunks, in comparison with warm control animals, revealed a thinner layer of Gcs on the free surface gastric epithelium with reduced depth of their pits. Cold-treated chipmunks showed similar staining patterns and lectin affinity for Gcs as compared with warm control animals. After long-term cold treatment, reduction in the amounts of Gcs were more severe in gastric pit epithelium and glandular mucous cells than in the free surface gastric epithelium. A significant reduction in immunostaining of nitric oxide synthase (NOS) was also observed in chipmunks after long-term cold-treatment. The changes in Gcs and NOS staining patterns may be interpreted in relation with a continued but reduced functioning of the gastric mucosa throughout hibernation. However, the findings in the present experimental model for hibernation, which shows significant changes in Gcs and NOS staining patterns, need to be demonstrated during seasonal hibernation in the wild.

Brain interleukin asymmetries and paw preference in mice

The two sides of the brain are differently involved in the modulation of immune responses as demonstrated by lesion and behavioral approaches. To study the interactions between cerebral cortex cytokines and brain lateralization, three groups of BALB/c mice were selected on the basis of their performance in the paw preference test (left-pawed, ambidextrous and right-pawed) and the levels of interleukin-1beta and interleukin-6 were measured in the two cerebral cortices after an intraperitoneal saline or lipopolysaccharide. Generally, right cortices had higher interleukin-1beta and interleukin-6 levels than left cortices for both saline and lipopolysaccharide-treated mice. A strong correlation between the levels of interleukin-1beta and interleukin-6 in right and left cortices and behavioral lateralization was observed. For the saline-treated mice: in their left cortices, interleukin-1beta levels were higher for ambidextrous mice than for right-pawed mice (P<0.05); in their right cortices, interleukin-6 levels were higher for ambidextrous mice than for right-/left-pawed mice, and right-pawed mice have higher levels of interleukin-6 than left-pawed mice (P<0.01). In their left cortices, interleukin-6 levels are higher for left-pawed mice than for both ambidextrous and right-pawed mice (P<0.01). In their left cortices, interleukin-6 levels are higher for left-pawed mice than for both ambidextrous and right-pawed mice (P<0.01). The quadratic curve equations showed that the levels of interleukin-1beta and interleukin-6 in the right/left cortices had a highly significant correlation with paw preference scores in both normal and lipopolysaccharide-treated mice. In conclusion, the present report demonstrated that the basal levels of interleukin-1beta and interleukin-6 were higher in the right cortex than left cortex in mice. There was a strong correlation between the levels of interleukin-1beta and interleukin-6 and behavioral lateralization, and cytokine asymmetries had a strong correlation with the direction and the intensity of behavioral lateralization.

Relationship between Egr-1 gene expression and apoptosis in esophageal carcinoma and precancerous lesions

AIM: To study the expression of early growth response gene-1 (Egr-1 gene) and Bcl-X/_L protein and its relationship with the cell apoptosis in human esophageal carcinoma(EC) and precancerous lesions.

METHODS: In situ hybridization(ISH), immunohistochemistry (IHC) and TUNEL method were used respectively to detect Egr-1mRNA,Egr-1 protein, apoptosis related-protein Bcl-X/_L and cell apoptosis in situ from 66 cases of esophageal squamous cell carcinoma and their upper cut edge and paracancerous mucosa.

RESULTS: Egr-1 gene in situ hybridization, Bcl-X/_L immunohistochemistry positive products were located in the cytoplasm, while Egr-1 immunohistochemistry and TUNEL positive signal were located in the nuclei. The apoptosis index(AI) and the frequency of apoptosis occurrence were increased gradually from precancerous lesion to cancer (P < 0.01) and the expression of Egr-1mRNA and Egr-1 protein in dysplasia was the highest among all specimens (P < 0.01). The AI of Egr-1 positive cancer tissues was much higher than that of Egr-1 negative cancer tissues (P < 0.01), while the AI of Bcl-X/_L positive cancer tissues was much lower than that of Bcl-X/_L negative cancer tissues (P < 0.01). The AI and Egr-1 expression were not correlated with invasiveness and lymphatic metastasis in EC.

CONCLUSION: Cell apoptosis was present through esophageal carcinogenesis. The expression of Egr-1 mRNA and Egr-1 protein were high in precancerous lesion of esophagus. The AI was increased significantly in Egr-1 positive squamous cell carcinoma. Egr-1 might promote apoptotic effect. Egr-1 expression and cell apoptosis may have an important biological significance in esophageal carcinogenesis.

Progressive transformation of immortalized esophageal epithelial cells

AIM: To investigate the progressive transformation of immortal cells of human fetal esophageal epithelium induced by human papillomavirus, and to examine biological criteria of sequential passage of cells, including cellular phenotype, proliferative rate, telomerase, chromosome and tumorigenicity.

METHODS: The SHEE cell series consisted of immortalized embryonic esophageal epithelium which was in malignant transformation when cultivated over sixty passages without co-carcinogens. Cells of the 10th, 31st, 60th and 85th passages were present in progressive development after being transfected with HPV. Cells were cultivated in a culture flask and 24-hole cultural plates. Progressive changes of morphology, cell growth, contact-inhibition, and anchorage-dependent growth characteristics were examined by phase contrast microscopy. The cell proliferation rate was assayed by flow cytometry. The modal number of chromosomes was analyzed. HPV18E₆E₇ was detected by Western blot methods and activities of telomerase were analyzed by TRAP. Tumorigenicity of cells was detected with soft agar plates cultivated and with tumor formation in SCID mice.

RESULTS: In morphological examination the 10th passage cells were in good differentiation, the 60th and 85th passages cells were in relatively poor differentiation, and the 31st passage cells had two distinct differentiations. The characteristics of the 85th and 60th passage cells were weakened at contact-inhibition and anchorage-dependent growth. Karyotypes of four stages of cells belonged to hyperdiploid or hypotriploid, and bimodal distribution of chromosomes appeared in the 31st and 60th passage cells. All of these characteristics combined with a increasing trend. The activities of telomerase were expressed in the latter three passages. Four fourths of SCID mice in the 85th passage cells and one fourth of SCID mice in the 60th passage cells developed tumors, but the cells in the 10th and 31st passage displayed no tumor formation.

CONCLUSION: In continual cultivation of fetal esophageal epithelial cells with transduction of HPV18E₆E₇, cells from the 10th to the 85th passage were changed gradually from preimmortal, immortal, precancerous to malignantly transformed stages. All of these changes were in a dynamic progressive process. The establishment of a continuous line of esophageal epithelium may provide a in vitro model of carcinogenesis induced by HPV.

Expression of histo-blood group A antigen increases resistance to apoptosis and facilitates escape from immune control of rat colon carcinoma cells

A and B histo-blood group antigens are present on carcinoma cells at the early stages of cancerogenesis and tend to disappear at later stages, but it is not yet clear whether they take part to the process of tumor progression. To gain some insight into this issue, we used a rat colon carcinoma experimental model. To obtain expression of the A antigen, REG cells were cotransfected with the rat A enzyme cDNA and a rat alpha1,2fucosyltransferase cDNA, either FTA or FTB, whereas PRO cells that spontaneously have alpha1,2fucosyltransferase activity were only transfected with the A enzyme cDNA. All A antigen-expressing transfected cells derived from either REG FTA, REG FTB, or PRO parental cells were more resistant to apoptosis induced by either serum deprivation or heat shock than were their respective controls. When injected to syngeneic immunocompetent rats, A enzyme-transfected PRO cells formed tumors that grew faster than those formed by mock-transfected PRO cells. However, in immunodeficient SCID mice, no difference in growth could be observed between the two types of tumors, indicating that the faster tumor growth of the A antigen-positive cells in immunocompetent animals was due to their higher ability to escape immune control and that this was associated with their higher degree of resistance to apoptosis. These results might explain the slightly augmented incidence of carcinomas observed in A and B blood group individuals compared to O individuals.

Comprehensive hereditary hemochromatosis genotyping

Hereditary hemochromatosis (HH) is an iron-overload disease common in populations of Northern European origin. Patients display increased iron absorption leading to excessive iron deposition and potential multiorgan failure. Using polymerase chain reaction sequence-specific primer (PCR-SSP) technology, we have developed an HH diagnosis assay capable of detecting 19 non-synonymous HFE mutations (including a previously unreported mutation, V295A) and several TFR2, SLC11A3 and H ferritin alleles implicated in HH. As part of the validation process, 159 UK renal donors were genotyped to determine HH allele frequencies in the UK population. The alleles nominally identified as HFE*01 (C282Y), HFE*02 (H63D) and HFE*03 (S65C) were found at frequencies of 0.085, 0.173 and 0.009, respectively. All other potential HH-associated alleles were absent, confirming their low prevalence in this population. This assay enables comprehensive routine HH genotyping, producing rapid, accurate and reproducible results at low cost.

Mu-opioid receptor mediates chronic restraint stress-induced lymphocyte apoptosis

Psychological stress is associated with immunosuppression in both humans and animals. Although it was well established that psychological stressors stimulate the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, resulting in the release of various hormones and neurotransmitters, the mechanisms underlying these phenomena are poorly understood. In this study, mu-opioid receptor knockout (MORKO) mice were used to investigate whether the mu-opioid receptor mediates the immunosuppression induced by restraint stress. Our results showed that wild-type (WT) mice subjected to chronic 12-h daily restraint stress for 2 days exhibited a significant decrease in splenocyte number with a substantial increase in apoptosis and CD95 (Fas/APO-1) expression of splenocytes. The effects are essentially abolished in MORKO mice. Furthermore, inhibition of splenic lymphocyte proliferation, IL-2, and IFN-gamma production induced by restraint stress in WT mice was also significantly abolished in MORKO mice. Interestingly, both stressed WT and MORKO mice showed a significant elevation in plasma corticosterone and pituitary proopiomelanocortin mRNA expression, although the increase was significantly lower in MORKO mice. Adrenalectomy did not reverse restraint stress-induced immunosuppression in WT mice. These data clearly established that the mu-opioid receptor is involved in restraint stress-induced immune alterations via a mechanism of apoptotic cell death, and that the effect is not mediated exclusively through the glucocorticoid pathway.

Changes in Na(+)-K(+)-Cl(-) cotransporter immunoreactivity in the gerbil hippocampus following transient ischemia

We examined alterations in Na(+)-K(+)-Cl(-) cotransporter 1 (NKCC1) immunoreactivity following ischemia. Twelve hours after ischemia, NKCC1 immunoreactivity in the CA1 region and in the hilar region was significantly diminished. Twenty-four hours after ischemia, NKCC1 immunoreactivity was intensified in these hippocampal regions as well as CA2-3. Two days after ischemia, NKCC1 immunoreactivity in the CA1 and the hilar neurons had disappeared, although in the CA2-3 and the granule cell layer NKCC1 immunoreactivities had recovered to the sham level. This finding suggests that NKCC1 may play an important role in the ischemic neuronal injury induced by excitotoxicity as well as neuronal edema.

Identification of differentially expressed proteins between human esophageal immortalized and carcinomatous cell lines by two-dimensional electrophoresis and MALDI-TOF-mass spectrometry

AIM: To identify the differentially expressed proteins between the human immortalized esophageal epithelial cell line (SHEE) and the malignant transformed esophageal carcinoma cell line (SHEEC), and to explore new ways for studying esophageal carcinoma associated genes.

METHODS: SHEE and SHEEC cell lines were used to separate differentially expressed proteins by two-dimensional electrophoresis. The silver-stained 2-D gels was scanned with EDAS290 digital camera system and analyzed with the PDQuest 6.2 Software. Six spots in which the differentially expressed protein was more obvious were selected and analyzed with matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS).

RESULTS: There were 107±4.58 and 115±9.91 protein spots observed in SHEE and SHEEC respectively, and the majority of these spots between the two cell lines matched each other (r = 0.772), only a few were expressed differentially. After analyzed by MALDI-TOF-MS and database search for the six differentially expressed proteins, One new protein as well as other five sequence-known proteins including RNPEP-like protein, human rRNA gene upstream sequence binding transcription factor, uracil DNA glycosylase, Annexin A2 and p300/CBP-associated factor were preliminarily identified.

CONCLUSION: These differentially expressed proteins might play an importance role during malignant transformation of SHEEC from SHEE. The identification of these proteins may serve as a new way for studying esophageal carcinoma associated genes.

HPV infections and oesophageal cancer

The first reports suggesting an involvement of human papillomavirus (HPV) in the development of both benign and malignant squamous cell tumours of the oesophagus date back to 1982. Since then, a substantial amount of literature has accumulated on this subject, summarised in this review. To date, 239 oesophageal squamous cell papillomas have been analysed in 29 separate studies using different HPV detection methods, with HPV being detected in 51 (21.3%) cases. Many more squamous cell carcinomas have been analysed: of the 1485 squamous cell carcinomas analysed by in situ hybridisation, 22.9% were positive for HPV DNA, as were 15.2% of the 2020 cases tested by the polymerase chain reaction. In addition, evidence derived from large scale serological studies, animal experiments, and in vitro studies is discussed in the light of the highly variable geographical incidence rates of oesophageal carcinoma worldwide. It may be that the (multifactorial) aetiology of oesophageal cancer differs greatly between those geographical areas with a low risk and those with a high risk for this disease. Oncogenic HPV types seem to play an important causal role, particularly in high risk areas.

HPV infections and oesophageal cancer

The first reports suggesting an involvement of human papillomavirus (HPV) in the development of both benign and malignant squamous cell tumours of the oesophagus date back to 1982. Since then, a substantial amount of literature has accumulated on this subject, summarised in this review. To date, 239 oesophageal squamous cell papillomas have been analysed in 29 separate studies using different HPV detection methods, with HPV being detected in 51 (21.3%) cases. Many more squamous cell carcinomas have been analysed: of the 1485 squamous cell carcinomas analysed by in situ hybridisation, 22.9% were positive for HPV DNA, as were 15.2% of the 2020 cases tested by the polymerase chain reaction. In addition, evidence derived from large scale serological studies, animal experiments, and in vitro studies is discussed in the light of the highly variable geographical incidence rates of oesophageal carcinoma worldwide. It may be that the (multifactorial) aetiology of oesophageal cancer differs greatly between those geographical areas with a low risk and those with a high risk for this disease. Oncogenic HPV types seem to play an important causal role, particularly in high risk areas.

Effects of exposure to extremely low-frequency magnetic field of 2 G intensity on memory and corticosterone level in rats

In the present study, we examined the effects of chronic exposure (1 and 2 weeks) to an extremely low-frequency magnetic field (ELFMF) of 2 G intensity on memory in rats using an object recognition task. Comparable groups of rats were exposed for 1, 2 or 4 weeks to ELFMF and the following day blood samples were collected from each rat for the measurement of corticosterone level. Our results demonstrate that exposure to ELFMF induces a significant increase in the level of corticosterone in blood plasma and is associated with impairment in discrimination between familiar and novel objects.

Comparative study of the micellar enhanced spectrophotometric determination of beta-lactamic antibiotics by batch and flow injection analysis using a multisimplex design

A study has been made on the spectrophotometric determination of the beta-lactamic antibiotics, amoxicillin and ampicillin, in micellar media using Cu ions as catalyst. Batch and flow injection approaches were compared. Multisimplex design was used to determine the optimal values of the flow injection analysis (FIA) system. Chemical (buffer, pH and Cu(II) concentrations) and physical (flow rate, temperature and reaction coil length) variables were considered. The analytical performance characteristics were as follows: the detection limits for batch and flow-through systems were 2.5 x 10(-7) and 2 x 10(-6) M, respectively, and a relative standard deviation less than 1% was found for both methods. The proposed FIA methodology was satisfactorily applied to the determination of the antibiotics in pharmaceutical formulations.