Individual response of humans to ionising radiation: governing factors and importance for radiological protection.

Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.

Phase I/II trial of definitive carbon ion radiotherapy for prostate cancer: evaluation of shortening of treatment period to 3 weeks.

BACKGROUND: The purpose of this study was to evaluate the feasibility of a new shortened 3-week treatment schedule of carbon ion radiotherapy (CIRT) for prostate cancer. METHODS: Beginning in May 2010, patients with T1b-T3bN0M0, histologically proven prostate adenocarcinoma were enrolled in the phase II trial of CIRT. Patients received 51.6 GyE in 12 fractions over 3 weeks (protocol 1002). The primary end point was defined as the incidence of late adverse events that were evaluated based on the Common Terminology Criteria for Adverse Events version 4.0. Biochemical failure was determined using the Phoenix definition (nadir +2.0 ng ml(-1)). RESULTS: Forty-six patients were enrolled, and all patients were included in the analysis. The number of low-, intermediate-, and high-risk patients was 12 (26%), 9 (20%), and 25 (54%), respectively. The median follow-up period of surviving patients was 32.3 months. Two patients had intercurrent death without recurrence, and the remaining 44 patients were alive at the time of this analysis. In the analysis of late toxicities, grade 1 (G1) rectal haemorrhage was observed in 3 (7%) patients. The incidence of G1 haematuria was observed in 6 (13%) patients, and G1 urinary frequency was observed in 17 (37%) patients. No ⩾G2 late toxicities were observed. In the analysis of acute toxicities, 2 (4%) patients showed G2 urinary frequency, and no other G2 acute toxicities were observed. CONCLUSIONS: The new shortened CIRT schedule over 3 weeks was considered as feasible. The analysis of long-term outcome is warranted.

Identification of serum miRNAs as novel non-invasive biomarkers for detection of high risk for early gastric cancer.

BACKGROUND: Many micro-RNAs (miRNAs) are differentially expressed in Helicobacter pylori-infected gastric mucosa and in gastric cancer tissue and previous reports have suggested the possibility of serum miRNAs as complementary tumour markers. The aim of the study was to investigate serum miRNAs and pepsinogen levels in individuals at high risk for gastric cancer both before and after H. pylori eradication. METHODS: Patients with recent history of endoscopic resection for early gastric cancer and the sex- and age-matched controls were enrolled. Serum was collected from subjects before or after eradication and total RNA was extracted to analyse serum levels of 24 miRNAs. Serum pepsinogen (PG) I and II levels were measured using enzyme-linked immunosorbent assay kits. RESULTS: Using miR-16 as an endogenous control, the relative levels of miR-106 and let-7d before and after H. pylori eradication and miR-21 after eradication were significantly higher in the high-risk group than in the controls. H. pylori eradication significantly decreased miR-106b levels and increased let-7d only in the control group. After eradication, the combination MiR-106b with miR-21 was superior to serum pepsinogen and the most valuable biomarker for the differentiating high-risk group from controls. CONCLUSION: Serum miR-106b and miR-21 may provide a novel and stable marker of increased risk for early gastric cancer after H. pylori eradication.

Dietary supplementation with 5-aminolevulinic acid modulates growth performance and inflammatory responses in broiler chickens.

The objective of this study was to investigate the effect of dietary supplementation with 5-aminolevulinic acid (5-ALA) on the immune system, inflammatory response, and growth performance of broiler chickens. The levels of cluster of differentiation 3 (CD3) mRNA in the spleens of chickens gradually increased with dietary 5-ALA concentration, while the expression levels of interleukin (IL)-2 decreased. Mitogen-induced proliferation of splenic mononuclear cells and blood mononuclear cell phagocytosis in chickens fed 0.001 and 0.01% 5-ALA-supplemented diets were significantly greater than in chickens fed a basal diet (control). Plasma thiobarbituric acid reactive substance (TBARS) concentration gradually increased along with 5-ALA supplement concentration. These results provide the first evidence that the use of dietary 0.001 and 0.01% 5-ALA supplementation induces the T-cell immune system via mild oxidative stress in chickens. Three hours after Escherichia coli lipopolysaccharide-induced immune stimulation, the levels of mRNA encoding pro-inflammatory cytokines, such as IL-6 and tumor necrosis factor-like ligand 1A (TL1A), in chickens fed a 0.001% 5-ALA-supplemented diet were significantly lower than those in chickens exposed to other treatments. The plasma caeruloplasmin concentration in chickens fed a 0.001% 5-ALA-supplemented diet was significantly lower than in controls or in chickens fed diets supplemented with other concentrations of 5-ALA 24 h after injection of LPS. In addition, BW at 21 and 50 d of age was significantly higher in chickens fed a 0.001% 5-ALA-supplemented diet than in control chickens. The findings suggest that supplementation of diets with 0.001% 5-ALA could prevent the catabolic changes induced by immunological stimulation. These results show that 5-ALA might be useful as an immunomodulator to stimulate T-cells via mild oxidative stress in growing broiler chickens, thereby improving the growth performance.

Influence of lower extremity rotation on knee kinematics in single-leg landing.

OBJECTIVES: Although the rotation of lower extremities has gained increasing recognition as a risk factor for anterior cruciate ligament (ACL) injury. This study clarified the influence of lower extremity rotation on the knee during single-leg landing. DESIGN AND SETTING: We recruited 30 students to perform single-leg landing from a height of 30 cm with their lower extremities in neutral, and externally and internally rotated. The knee abduction, flexion angles, and abduction angular velocity were measured. Furthermore, the abduction angle was analyzed at knee flexion angles of 15°, 20°, 25°, and 30° and compared among the three conditions using a repeated measures analysis of variance with Bonferroni post hoc tests. RESULTS: The maximum abduction angle was significantly greater when internally rotated than in the neutral. The maximum abduction angular velocity was significantly greater in the internally rotated compared to in the neutral. Finally, the abduction angle at a knee flexion angle of 30° was significantly greater when internally rotated compared to in the neutral. CONCLUSION: Rotation of the lower extremities affects knee kinematics, and landing on a knee that is internally rotated may increase the risk of ACL injury.

Hypoxia/reoxygenation-mediated induction of astrocyte interleukin 6: a paracrine mechanism potentially enhancing neuron survival.

To elucidate mechanisms underlying neuroprotective properties of astrocytes in brain ischemia, production of neurotrophic mediators was studied in astrocytes exposed to hypoxia/reoxygenation (H/R). Rat astrocytes subjected to H/R released increased amounts of interleukin (IL) 6 in a time-dependent manner, whereas levels of tumor necrosis factor and IL-1 remained undetectable. IL-6 transcripts were induced in hypoxia and the early phase of reoxygenation, whereas synthesis and release of IL-6 antigen/activity occurred during reoxygenation. Elevated levels of IL-6 mRNA were due, at least in part, to increased transcription, as shown by nuclear runoff analysis. The mechanism stimulating synthesis and release of IL-6 antigen by astrocytes was probably production of reactive oxygen intermediates (ROIs), which occurred within 15-20 minutes after placing hypoxia cultures back into normoxia, as the inhibitor diphenyl iodonium inhibited the burst of ROIs and subsequent IL-6 generation (blockade of nitric oxide formation had no effect on ROI generation or IL-6 production). Enhanced IL-6 generation was also observed in human astrocytoma cultures exposed to H/R. Survival of differentiated PC12 cells exposed to H/R was potentiated by conditioned medium from H/R astrocytes, an effect blocked by neutralizing anti-IL-6 antibody. In a gerbil model of brain ischemia, IL-6 activity was lower in the hippocampus, an area sensitive to ischemia, compared with IL-6 activity in the cortex, an area more resistant to ischemia. IL-6 antigen, demonstrated immunohistochemically, was increased in astrocytes from ischemic regions of gerbil brain. These data suggest that H/R enhances transcription of IL-6, resulting in increased translation and release of IL-6 antigen after the burst of ROI generated early during reoxygenation. Release of IL-6 from astrocytes could exert a paracrine neurotrophic effect in brain ischemia.

Immunomodulation in gut-associated lymphoid tissue of neonatal chicks by immunobiotic diets.

Developmental changes in immunocompetent cells of the gut during the first week posthatch were determined in broiler chicks fed immunobiotic lactic acid bacteria in the form of Lactobacillus jensenii TL2937-, Lactobacillus gasseri JCM1131(T)-, Lactobacillus delbrueckii ssp. bulgaricus NIAIB6-, or L. gasseri TL2919-supplemented diets. The relative weights of spleen and bursa of Fabricius in chicks fed the immunobiotic diets were slightly higher than the control valued at 1 and 3 d of age, with the exception of spleen weight in the L. gasseri JCM1131(T) at 3 d of age, the bursa of Fabricius weight in the L. gasseri JCM1131(T) at 1 and 3 d of age, and bursa of Fabricius weight in the L. gasseri TL2919 group at 1 d of age. There were no significant differences in body and liver weights among the treatments. When chicks were fed the L. jensenii TL2937- or L. gasseri TL2919-supplemented diets, expression of T cell-related mRNA [cluster of differentiation 3 (CD3), interleukin-2 (IL-2), and interferon-gamma (IFN-gamma)] in the foregut was significantly higher than that of control chicks at 3 or 7 d of age. Expression levels of toll-like receptor (TLR) mRNA tended to increase in the foregut of chicks fed the immunobiotic diets, except for the L. delbrueckii ssp. bulgaricus NIAIB6, compared with expression levels in control chicks. The Bu-1 mRNA expression levels in the bursa of Fabricius were not affected by the supplementations with immunobiotic lactic acid bacteria. These results show that immunobiotics, particularly L. gasseri TL2919, might be useful as immunomodulators to stimulate the gut-associated immune system in neonatal chicks, and thereby protect them from disease without decreasing growth performance as a possible substitution of antibiotics.

Adipose tissue fat accumulation is reduced by a single intraperitoneal injection of peroxisome proliferator-activated receptor gamma agonist when given to newly hatched chicks.

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a transcription factor that regulates adipocyte differentiation and modulates lipid metabolism in mammals. The aim of the present study was to investigate whether the administration of PPARgamma ligands, adipogenic cocktail, or both to newly hatched chicks regulates adipocyte differentiation in vivo and modulates fat deposition in growing broiler chickens. Levels of PPARgamma, CCAAT/enhancer binding protein alpha, and adipocyte fatty acid-binding protein mRNA in the abdominal fat pad of 7-d-old broiler chicks given a single intraperitoneal dose of troglitazone, a synthetic PPARgamma ligand, at 1 d old were significantly greater than those in control chickens. This suggests administration of troglitazone enhanced adipocyte differentiation in vivo. Adipose tissue weight in 28-d-old chickens similarly administered triolein emulsion containing troglitazone or adipogenic cocktail (i.e., dexamethasone, insulin, isobutyl-methylxanthine, and oleic acid) was also significantly less than that of control chickens. However, there was no significant difference in BW between treated and control chickens. Although BW and carcass composition were not different between troglitazone-treated and control chickens, at 48 d of age abdominal fat pad weight and feed intake were significantly decreased in chickens treated with troglitazone compared with controls. These results demonstrate that a single intraperitoneal injection of troglitazone to newly hatched chicks reduces fat deposition in mature broiler chickens.

Glomerulosclerosis induced by in vivo transfection of transforming growth factor-beta or platelet-derived growth factor gene into the rat kidney.

Glomerulosclerosis, a final common lesion of various glomerular diseases, is characterized by mesangial cell proliferation and extracellular matrix (ECM) expansion. TGF-beta and PDGF are known to play a critical role in the regulation of ECM metabolism and mesenchymal cell proliferation, respectively. However, there is little evidence to demonstrate the direct role of each of these growth factors in the pathogenesis of glomerulosclerosis. Using an in vivo transfection technique, we could realize the selective overexpression of single growth factor in the kidney. The introduction of either TGF-beta or PDGF-B gene alone into the kidney induced glomerulosclerosis, although the patterns of action of these growth factors were different; TGF-beta affected ECM accumulation rather than cell proliferation and PDGF affected the latter rather than the former.

Localization and rapid regulation of Na+/myo-inositol cotransporter in rat kidney.

myo-inositol, a major compatible osmolyte in renal medulla, is accumulated in several kinds of cells under hypertonic conditions via Na+/myo-inositol cotransporter (SMIT). To investigate the physiological role of the SMIT, we sought to determine its localization by in situ hybridization and its acute regulation by NaCl and furosemide administration. Northern analysis demonstrated that SMIT is strongly expressed in the medulla and at low levels in the cortex of kidney. Intraperitoneal injection of NaCl rapidly induced SMIT mRNA in both the cortex and medulla, and furosemide completely abolished this induction. In situ hybridization revealed that SMIT it predominantly present in the medullary and cortical thick ascending limbs of Henle's loop (TALH) and macula densa cells. Less intense signals were seen in the inner medullary collecting ducts (IMCD). NaCl loading increased the signals throughout the TALH, and furosemide reduced the signals. SMIT in the IMCD is less sensitive to these kinds of acute regulation. Thus, the distribution pattern of SMIT does not correspond to the corticomedullary osmotic gradient, and SMIT in the TALH and macula densa cells is regulated very rapidly. These results suggest that SMIT expression in TALH may be regulated by intracellular and/or peritubular tonicity close to the basolateral membrane, which is supposed to be proportional to the magnitude of NaCl reabsorption.

Mitogen-activated protein kinase and its activator are regulated by hypertonic stress in Madin-Darby canine kidney cells.

Madin-Darby canine kidney cells behave like the renal medulla and accumulate small organic solutes (osmolytes) in a hypertonic environment. The accumulation of osmolytes is primarily dependent on changes in gene expression of enzymes that synthesize osmolytes (sorbitol) or transporters that uptake them (myo-inositol, betaine, and taurine). The mechanism by which hypertonicity increases the transcription of these genes, however, remains unclear. Recently, it has been reported that yeast mitogen-activated protein (MAP) kinase and its activator, MAP kinase-kinase, are involved in osmosensing signal transduction and that mutants in these kinases fail to accumulate glycerol, a yeast osmolyte. No information is available in mammals regarding the role of MAP kinase in the cellular response to hypertonicity. We have examined whether MAP kinase and MAP kinase-kinase are regulated by extracellular osmolarity in Madin-Darby canine kidney cells. Both kinases were activated by hypertonic stress in a time- and osmolarity-dependent manner and reached their maximal activity within 10 min. Additionally, it was suggested that MAP kinase was activated in a protein kinase C-dependent manner. These results indicate that MAP kinase and MAP kinase-kinase(s) are regulated by extracellular osmolarity.

Induction of manganese superoxide dismutase in rat cardiac myocytes increases tolerance to hypoxia 24 hours after preconditioning.

Manganese superoxide dismutase (Mn-SOD) is induced in ischemic hearts 24 h after ischemic preconditioning, when tolerance to ischemia is acquired. We examined the relationship between Mn-SOD induction and the protective effect of preconditioning using cultured rat cardiac myocytes. Exposure of cardiac myocytes to brief hypoxia (1 h) decreased creatine kinase release induced by sustained hypoxia (3 h) that follows when the sustained hypoxia was applied 24 h after hypoxic preconditioning (57% of that in cells without preconditioning). The activity and content of Mn-SOD in cardiac myocytes were increased 24 h after hypoxic preconditioning (activity, 170%; content, 139% compared with cells without preconditioning) coincidentally with the acquisition of tolerance to hypoxia. Mn-SOD mRNA was also increased 20-40 min after preconditioning. Antisense oligodeoxyribonucleotides corresponding to the initiation site of Mn-SOD translation inhibited the increases in the Mn-SOD content and activity and abolished the expected decrease in creatine kinase release induced by sustained hypoxia after 24 h of hypoxic preconditioning. Sense oligodeoxyribonucleotides did not abolish either Mn-SOD induction or tolerance to hypoxia. These results suggest that the induction of Mn-SOD in myocytes by preconditioning plays a pivotal role in the acquisition of tolerance to ischemia at a later phase (24 h) of ischemic preconditioning.

Na+/myo-inositol transport is regulated by basolateral tonicity in Madin-Darby canine kidney cells.

We investigated the effects of change in basolateral osmolality on Na(+)-dependent myo-inositol uptake in Madin-Darby canine kidney cells to test our hypothesis that the Na+/myo-inositol transporter (SMIT), an osmolyte transporter, is mainly regulated by osmolality on the basolateral surface. A significant osmotic gradient between both sides of the epithelium persisted at least 10 h after basolateral osmolality was increased. [3H]myo-inositol uptake increased in a basolateral osmolality-dependent manner. The magnitude of the increase is comparable to that for making both sides hypertonic. Apical hypertonicity also increased the uptake on the basal side, but the magnitude of the increase was significantly smaller than the basolateral or both sides hypertonicity. Betaine-gamma-amino-n-butyric acid transporter activity, measured by [3H]gamma-amino-n-butyric uptake, showed a pattern similar to SMIT activity in response to basolateral hypertonicity. The most plausible explanation for the polarized effect of hypertonicity is that the basal membrane is much more water permeable than the apical membrane. These results seem to be consistent with the localization and regulation of the SMIT in vivo.

Glycation-dependent, reactive oxygen species-mediated suppression of the insulin gene promoter activity in HIT cells.

Prolonged poor glycemic control in non-insulin-dependent diabetes mellitus patients often leads to a decline in insulin secretion from pancreatic beta cells, accompanied by a decrease in the insulin content of the cells. As a step toward elucidating the pathophysiological background of the so-called glucose toxicity to pancreatic beta cells, we induced glycation in HIT-T15 cells using a sugar with strong deoxidizing activity, D-ribose, and examined the effects on insulin gene transcription. The results of reporter gene analyses revealed that the insulin gene promoter is more sensitive to glycation than the control beta-actin gene promoter; approximately 50 and 80% of the insulin gene promoter activity was lost when the cells were kept for 3 d in the presence of 40 and 60 mM D-ribose, respectively. In agreement with this, decrease in the insulin mRNA and insulin content was observed in the glycation-induced cells. Also, gel mobility shift analyses using specific antiserum revealed decrease in the DNA-binding activity of an insulin gene transcription factor, PDX-1/IPF1/STF-1. These effects of D-ribose seemed almost irreversible but could be prevented by addition of 1 mM aminoguanidine or 10 mM N-acetylcysteine, thus suggesting that glycation and reactive oxygen species, generated through the glycation reaction, serve as mediators of the phenomena. These observations suggest that protein glycation in pancreatic beta cells, which occurs in vivo under chronic hyperglycemia, suppresses insulin gene transcription and thus can explain part of the beta cell glucose toxicity.

Mitochondrial coupling factor 6 as a potent endogenous vasoconstrictor.

We demonstrated recently that coupling factor 6, an essential component of the energy-transducing stalk of mitochondrial ATP synthase, suppresses the synthesis of prostacyclin in vascular endothelial cells. Here, we tested the hypothesis that coupling factor 6 is present on the cell surface and is involved in the regulation of systemic circulation. This peptide is present on the surface of CRL-2222 vascular endothelial cells and is released by these cells into the medium. In vivo, the peptide circulates in the vascular system of the rat, and its gene expression and plasma concentration are higher in spontaneously hypertensive rats (SHRs) than in normotensive controls. Elevation of blood pressure with norepinephrine did not affect the plasma concentration of coupling factor 6. Intravenous injection of recombinant peptide increased blood pressure, apparently by suppressing prostacyclin synthesis, whereas a specific Ab to coupling factor 6 decreased systemic blood pressure concomitantly with an increase in plasma prostacyclin. Interestingly, the antibody's hypotensive effect could be abolished by treating with the cyclooxygenase inhibitor indomethacin. These findings indicate that mitochondrial coupling factor 6 functions as a potent endogenous vasoconstrictor in the fashion of a circulating hormone and may suggest a new mechanism for hypertension.

Usefulness of 11C-methionine-PET for predicting the efficacy of carbon ion radiation therapy for head and neck mucosal malignant melanoma.

The aim of this study was to determine whether l-methyl-[11C]-methionine (MET) positron emission tomography (PET) allows the prediction of outcomes in patients with head and neck mucosal malignant melanoma treated with carbon ion radiation therapy (CIRT). This was a retrospective cohort study involving 85 patients who underwent a MET-PET or MET-PET/computed tomography (CT) examination before and after CIRT. MET uptake in the tumour was evaluated semi-quantitatively using the tumour-to-normal tissue ratio (TNR). Local recurrence, metastasis, and outcome predictions were studied in terms of TNR before CIRT (TNRpre), TNR after CIRT (TNRpost), and the TNR change ratio. Kaplan-Meier curves revealed significant differences between patients with higher TNRpre values and those with lower TNRpre values in regard to local recurrence, metastasis, and outcome (log-rank test P<0.0001 for all three). There were also significant differences in metastasis rates and outcomes between patients with higher and lower TNRpost values (log-rank test P=0.0105 and P=0.027, respectively). The Cox proportional hazards model revealed TNRpre to be a factor significantly influencing the risk of local recurrence (hazard ratio (HR) 29.0, P<0.001), risk of metastasis (HR 2.67, P=0.024), and the outcome (HR 6.3, P<0.001). MET-PET or MET-PET/CT is useful for predicting the outcomes of patients with head and neck mucosal malignant melanoma treated with CIRT.

Anti-parietal cell antibody and serum pepsinogen assessment in screening for gastric carcinoma.

BACKGROUND: Anti-parietal cell antibody is found in patients with Helicobacter pylori-positive gastritis and is related to atrophic gastritis and gastric carcinoma. AIM: To identify the characteristics of patients at high-risk for gastric carcinoma in terms of anti-parietal cell antibody and serum pepsinogen. PATIENTS AND METHODS: Subjects were 92 H. pylori-positive patients (54 men, 38 women; mean age, 57.9 years; range, 15-88 years). The serum concentrations of pepsinogen I and II were determined by radioimmunoassay, and the presence of anti-parietal cell antibody was assessed by enzyme-linked immunosorbent assay. Degrees of inflammation and atrophy in the corpus of the stomach were evaluated histologically. RESULTS: Patients were classified into four groups according to anti-parietal cell antibody status and pepsinogen I/II ratio. Anti-parietal cell antibody-negative/pepsinogen I/II-low patients had the highest risk for gastric carcinoma (prevalence of gastric carcinoma: 7/13=53.8%, odds ratio=7.6, 95% confidence interval, 1.2-48.0). Anti-parietal cell antibody titre was high when inflammation in the corpus was severe (p=0.06) and significantly low when atrophy in the corpus was severe (p=0.01). CONCLUSION: Our results showed that patients with a negative anti-parietal cell antibody titre and low pepsinogen I/II ratio are at high-risk for gastric carcinoma.

Selective suppression of N-acetylglucosaminyltransferase III activity in a human hepatoblastoma cell line transfected with hepatitis B virus.

UDP-N-acetylglucosamine: beta-D-mannoside beta-1,4-N-acetylglucosaminyl-transferase III (GnT-III) is a key enzyme in the branching of asparagine-linked oligosaccharides, which are present in surface membrane proteins of various tissues and in secretory glycoproteins. The activity of GnT-III was assayed in 2 human hepatoblastoma cell lines, Huh6, which was the parental cell line, and HB611, which was established by transfection of 3 tandem copies of the hepatitis B virus genome into Huh6. A significant difference in GnT-III activity was found between Huh6 and HB611 (136 +/- 18.3 pmol/h/mg versus 6.7 +/- 2.4 pmol/h/mg; mean +/- SD, P < 0.001), whereas levels of the glycosyltransferases alpha-3-D-mannoside beta-1,4-N-acetylglucosaminyltransferase IV, alpha-6-D-mannoside beta-1,6-N-acetylglucosaminyltransferase-V, and beta-1,4-galactosyltransferase were almost the same in both cell lines. Northern blot analysis indicated that the decreased activity of GnT-III in HB611 was due to the decreased transcript. When HB611 was treated with interferon-alpha, expression of hepatitis B virus-related mRNA decreased, and the activity of GnT-III increased from 8.5 +/- 3.8 to 22.0 +/- 7.2 pmol/h/mg (mean +/- SD, P < 0.05). This increase was not found in Huh6. Binding capacity with erythrocyte phytohemagglutinin in these cells using fluorescence-activated cell sorter analysis was different, suggesting that the structure of sugar chain on the cell surface might be altered by suppression of GnT-III activity. This is the first report that hepatitis B virus selectively suppressed the GnT-III activity in hepatoblastoma cells.

N-acetylglucosaminyltransferase III and V messenger RNA levels in LEC rats during hepatocarcinogenesis.

The LEC (Long-Evans with a cinnamon-like color) rat is a mutant of the Long-Evans strain which develops hereditary hepatitis and hepatoma with age. Activities and mRNA levels of N-acetylglucosaminyltransferase III and V (GnT-III and GnT-V, respectively) were determined during hepatocarcinogenesis in this rat using a LEA (Long-Evans with an agouti color) rat as a control. GnT-III activity in LEC rat liver increased after 30 weeks of age, at the stage of chronic hepatitis, to about 2.5-11.5 times the level in LEC rats aged 1-9 weeks. GnT-V activity in the LEC rat liver increased after 20 weeks of age, at the stage of acute hepatitis, to about 1.5-2.5 times the level in LEC rats of 1-9 weeks of age and then remained elevated. Both enzymes showed more dramatic increases in males than in females. The mRNA levels of the enzymes increased in proportion with the enzyme activities. Furthermore, GnT-III and GnT-V mRNAs were highly expressed in both cancer lesion and adjacent tissues. In one case of hepatoma with lymph node metastasis, GnT-III and GnT-V mRNA expression was much higher in the metastatic lesion than in the original cancer. GnT-III and GnT-V levels in the original cancer lesions were similar to those in the cancer lesions of the other LEC rats. These results indicated that expression of GnT-III and GnT-V was induced by chronic liver damage and hepatocarcinogenic changes in the LEC rats.

Expression of vascular permeability factor/vascular endothelial growth factor in human hepatocellular carcinoma.

Vascular permeability factor (VPF)/vascular endothelial growth factor (VEGF) is unique in its ability to promote vascular permeability and endothelial cell growth, and its role in tumor development has received considerable attention. In this report, we describe the elevation of VPF/VEGF transcript expression in human hepatocellular carcinoma. Surgical samples of 23 patients with hepatocellular carcinoma were studied using reverse transcription-PCR analysis. The oligonucleotide primers were designed to amplify all four known splicing variants that could be expressed in the samples studied. Sixteen cases showed VPF/VEGF transcript expression in the tumor (16/23, 69.6%), whereas only 9 of the 23 patients showed it in the corresponding nontumoral part. There was no difference between the pattern of expression of VPF/VEGF isoforms in tumoral and nontumoral tissues. VPF/VEGF mRNA expression in the liver tumors was associated with fibrous capsule formation and septal formation (P < 0.05 respectively, Fisher's exact P test). In situ hybridization confirmed the presence of VPF/VEGF mRNA expression in tumor cells and less intensely in hepatocytes of nontumoral liver. We also found that VPF/VEGF expression in the tumor cell was increased in the area adjacent to necrotic regions (presumably hypoxic regions). As a regulator of vascular permeability and endothelial cell growth factor, VPF/VEGF may play an important role in the development of hepatocellular carcinoma.