Glutathione S-transferase mu modulates the stress-activated signals by suppressing apoptosis signal-regulating kinase 1

Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase that can activate the c-Jun N-terminal kinase and the p38 signaling pathways. It plays a critical role in cytokine- and stress-induced apoptosis. To further characterize the mechanism of the regulation of the ASK1 signal, we searched for ASK1-interacting proteins employing the yeast two-hybrid method. The yeast two-hybrid assay indicated that mouse glutathione S-transferase Mu 1-1 (mGSTM1-1), an enzyme involved in the metabolism of drugs and xenobiotics, interacted with ASK1. We subsequently confirmed that mGSTM1-1 physically associated with ASK1 both in vivo and in vitro. The in vitro binding assay indicated that the C-terminal portion of mGSTM1-1 and the N-terminal region of ASK1 were crucial for binding one another. Furthermore, mGSTM1-1 suppressed stress-stimulated ASK1 activity in cultured cells. mGSTM1-1 also blocked ASK1 oligomerization. The ASK1 inhibition by mGSTM1-1 occurred independently of the glutathione-conjugating activity of mGSTM1-1. Moreover, mGSTM1-1 repressed ASK1-dependent apoptotic cell death. Taken together, our findings suggest that mGSTM1-1 functions as an endogenous inhibitor of ASK1. This highlights a novel function for mGSTM1-1 insofar as mGSTM1-1 may modulate stress-mediated signals by repressing ASK1, and this activity occurs independently of its well-known catalytic activity in intracellular glutathione metabolism.

Identification of a neuronal nitric oxide synthase in isolated cardiac mitochondria using electrochemical detection

Mitochondrial nitric oxide synthase (mtNOS), its cellular NOS isoform, and the effects of mitochondrially produced NO on bioenergetics have been controversial since mtNOS was first proposed in 1995. Here we functionally demonstrate the presence of a NOS in cardiac mitochondria. This was accomplished by direct porphyrinic microsensor measurement of Ca(2+)-dependent NO production in individual mitochondria isolated from wild-type mouse hearts. This NO production could be inhibited by NOS antagonists or protonophore collapse of the mitochondrial membrane potential. The similarity of mtNOS to the neuronal isoform was deduced by the absence of NO production in the mitochondria of knockout mice for the neuronal, but not the endothelial or inducible, isoforms. The effects of mitochondrially produced NO on bioenergetics were studied in intact cardiomyocytes isolated from dystrophin-deficient (mdx) mice. mdx cardiomyocytes are also deficient in cellular endothelial NOS, but overexpress mtNOS, which allowed us to study the mitochondrial enzyme in intact cells free of its cytosolic counterpart. In these cardiomyocytes, which produce NO beat-to-beat, inhibition of mtNOS increased myocyte shortening by approximately one-fourth. Beat-to-beat NO production and altered shortening by NOS inhibition were not observed in wild-type cells. A plausible mechanism for the reversible NO inhibition of contractility in these cells involves the reaction of NO with cytochrome c oxidase. This suggests a modulatory role for NO in oxidative phosphorylation and, in turn, myocardial contractility.

Cloning of a unique lipase from endothelial cells extends the lipase gene family

A new lipoprotein lipase-like gene has been cloned from endothelial cells through a subtraction methodology aimed at characterizing genes that are expressed with in vitro differentiation of this cell type. The conceptual endothelial cell-derived lipase protein contains 500 amino acids, including an 18-amino acid hydrophobic signal sequence, and is 44% identical to lipoprotein lipase and 41% identical to hepatic lipase. Comparison of primary sequence to that of lipoprotein and hepatic lipase reveals conservation of the serine, aspartic acid, and histidine catalytic residues as well as the 10 cysteine residues involved in disulfide bond formation. Expression was identified in cultured human umbilical vein endothelial cells, human coronary artery endothelial cells, and murine endothelial-like yolk sac cells by Northern blot. In addition, Northern blot and in situ hybridization analysis revealed expression of the endothelial-derived lipase in placenta, liver, lung, ovary, thyroid gland, and testis. A c-Myc-tagged protein secreted from transfected COS7 cells had phospholipase A1 activity but no triglyceride lipase activity. Its tissue-restricted pattern of expression and its ability to be expressed by endothelial cells, suggests that endothelial cell-derived lipase may have unique functions in lipoprotein metabolism and in vascular disease.

Endoscopic ultrasound-guided versus conventional transmural drainage for pancreatic pseudocysts: a prospective randomized trial

BACKGROUND AND STUDY AIMS

Although endoscopic ultrasound (EUS)-guided transmural drainage (EUD) is preferred over conventional transmural drainage (CTD) of pancreatic pseudocysts by endoscopy in many centers, its superiority with respect to technical success and clinical outcome has not yet been demonstrated in a prospective randomized trial. We conducted this prospective randomized trial to compare the technical success and clinical outcomes of EUD and CTD in treating pancreatic pseudocysts.

PATIENTS AND METHODS

A total of 60 consecutive patients with pancreatic pseudocysts were randomly divided into two groups to undergo either EUD (n = 31) or CTD (n = 29) of pancreatic pseudocysts. The technical success rate, complications, and short-term and long-term results were prospectively evaluated.

RESULTS

The rate of technical success of the drainage was higher for EUD (94 %, 29/31) than for CTD (72 %, 21/29; P = 0.039) in intention-to-treat analysis. In cases where CTD failed (n = 8), because the pseudocysts were nonbulging, a crossover was made to EUD, which was successfully performed in all these patients. Complications occurred in 7 % of the EUD and 10 % of the CTD group ( P = 0.67). During short-term follow-up, pseudocyst resolution was achieved in 97 % (28/29) in the EUD group and in 91 % (19/21) in the CTD group ( P = 0.565). Long-term results analyzed on a per-protocol basis showed no significant difference in clinical outcomes between EUD (89 %, 33/37) and CTD (86 %, 18/21, P = 0.696).

CONCLUSIONS

We found that EUD and CTD can both be considered first-line methods of endoscopic transmural drainage of bulging pseudocysts, whereas EUD should be preferred for nonbulging pseudocysts.

APP processing and synaptic plasticity in presenilin-1 conditional knockout mice

We have developed a presenilin-1 (PS1) conditional knockout mouse (cKO), in which PS1 inactivation is restricted to the postnatal forebrain. The PS1 cKO mouse is viable and exhibits no gross abnormalities. The carboxy-terminal fragments of the amyloid precursor protein differentially accumulate in the cerebral cortex of cKO mice, while generation of beta-amyloid peptides is reduced. Expression of Notch downstream effector genes, Hes1, Hes5, and Dll1, is unaffected in the cKO cortex. Although basal synaptic transmission, long-term potentiation, and long-term depression at hippocampal area CA1 synapses are normal, the PS1 cKO mice exhibit subtle but significant deficits in long-term spatial memory. These results demonstrate that inactivation of PS1 function in the adult cerebral cortex leads to reduced Abeta generation and subtle cognitive deficits without affecting expression of Notch downstream genes.

Correlation of the apparent diffusion coefficiency values on diffusion-weighted imaging with prognostic factors for breast cancer

OBJECTIVE

The aim of this study was to correlate the apparent diffusion coefficient (ADC) value of breast cancer with prognostic factors.

METHODS

335 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) and ductal carcinoma in situ (DCIS) who underwent breast MRI with diffusion-weighted imaging were included in this study. ADC of breast cancer was calculated using two b factors (0 and 1000 s mm(-2)). Mean ADCs of IDC NOS and DCIS were compared and evaluated. Among cases of IDC NOS, mean ADCs were compared with lymph node status, size and immunochemical prognostic factors using Student's t-test. ADC was also correlated with histological grade using the Kruskal-Wallis test.

RESULTS

Mean ADC of IDC NOS was significantly lower than that of DCIS (p<0.001). However, the mean ADC of histological grade of IDC NOS was not significantly different (p=0.564). Mean ADC of oestrogen receptor (ER)-positive or progesterone receptor (PR)-positive cancer was significantly lower than that of ER-negative or PR-negative cancer (p=0.003 vs p=0.032). Mean ADC of Ki-67 index-positive cancer was significantly lower than that of Ki-67 index-negative cancer (p=0.028). Mean ADC values of cancers with increased microvascular density (MVD) were significantly lower than those of cancer with no MVD increase (p=0.009). No correlations were observed between mean ADC value and human growth factor receptor 2 expression, tumour size and lymph node metastasis.

CONCLUSION

Low ADC value was correlated with positive expression of ER, PR, increased Ki-67 index, and increased MVD of breast cancer.

A competence regulon in Streptococcus pneumoniae revealed by genomic analysis

Transformation in bacteria is the uptake and incorporation of exogenous DNA into a cell's genome. Several species transform naturally during a regulated state defined as competence. Genetic elements in Streptococcus pneumoniae induced during transformation were identified by combining a genetic screen with genomic analysis. Six loci were discovered that composed a competence-induced regulon. These loci shared a consensus promoter sequence and encoded proteins, some of which were similar to proteins involved in DNA processing during transformation in other bacteria. Each locus was induced during competence and essential for genetic transformation.

Effect of cigarette smoking and alcohol consumption in the aetiology of cancer of the oral cavity, pharynx and larynx

This study presents a comparative risk pattern for cancer of the oral cavity, pharynx and larynx, in relation to cigarette smoking and alcohol consumption based on data from case-control studies conducted in Korea Cancer Center Hospital, Seoul, Korea. The risk of cancer of the oral cavity, pharynx and larynx rose for current smokers and declined for ex-smokers. In males the odds ratios (ORs) for these sites rose with duration of smoking and number of cigarettes smoked per day. The relationship is strongest for laryngeal cancer. The risk for all sites was elevated linearly as amount and frequency of alcohol intake increased. Heavy drinkers, i.e. males who drank 90 g ethanol daily had an approximately 15-fold risk of cancer of the oral cavity, an 11-fold risk of pharyngeal cancer and an 11-fold risk of laryngeal cancer compared with non-drinkers. Alcohol drinking was a much stronger risk factor for cancer of the oral cavity than cancer of the pharynx and larynx. Alcohol was a much weaker risk factor for laryngeal cancer than cigarette smoking. Cancer of the oral cavity, pharynx and larynx also showed an interaction between smoking and alcohol, suggesting a synergistic effect.

Non-organ specific cancer prevention of ginseng: a prospective study in Korea

BACKGROUND

A number of studies have reported that increased consumption of natural products reduced the risk of cancer. Our previous case-control studies have shown a significant reduction in the risk of cancer development among those who regularly consumed ginseng. We conducted a prospective cohort study to evaluate the preventive effect of ginseng against cancer on a population residing in a ginseng cultivation area on the basis of the result of case-control studies.

METHODS

This study was conducted in Kangwha-eup from August 1987 to December 1992. We studied 4634 people over 40 years old who completed a questionnaire on ginseng intake. In an attempt to obtain detailed information about ginseng intake, we asked them to specify their age at initial intake, their frequency and duration of ginseng intake, the kind of ginseng, etc. Multiple logistic regression was used to estimate relative risks (RR) when controlling simultaneously for covariates.

RESULTS

Ginseng consumers had a decreased risk (RR = 0.40, 95% confidence interval [CI] : 0.28-0.56) compared with non-consumers. On the type of ginseng, the RR was 0.31 (95% CI: 0.13-0.74) for fresh ginseng extract consumers and 0.34 (95% CI: 0.20-0.53) for consumers of multiple combinations. There was no cancer death among 24 red ginseng consumers. There was a decreased risk with a rise in the frequency of ginseng intake, showing a dose-response relationship. The RR of ginseng consumers were 0.33 (95% CI: 0.18-0.57) in gastric cancer and 0.30 (95% CI : 0.14-0.65) in lung cancer. Among ginseng preparations, fresh ginseng extract consumers were significantly associated with a decreased risk of gastric cancer (RR = 0.33, 95% CI: 0.12-0.88).

CONCLUSIONS

These results strongly suggest that Panax ginseng C.A. Meyer has non-organ specific preventive effect against cancer, providing support for the previous case-control studies.

Clinical application of computer-aided rapid prototyping for tooth transplantation

The maintenance of healthy periodontal ligament cells in the donor tooth is one of the most important factors for successful tooth transplantation. This is achieved by minimizing the extraoral time during the surgical procedure. If a duplicate form of donor tooth could be obtained before extraction, it would be possible to precontour the recipient alveolar bone compatible with the donor tooth, and thereby reduce the extra-oral time of the donor tooth. We obtained a three-dimensional image with the real dimensions of the donor tooth from a CT Highspeed Advantage, allowing a life-sized resin model of the tooth to be fabricated. From 22 clinical cases, we achieved an average total transplantation time of 7.7 min. The average distance between the transplanted root surface and the alveolar bone from 12 available cases was 0.87 mm at the mesial cervix, 0.91 mm at the mesial apex, 0.98 mm at the distal cervix and 1.16 mm at the distal apex on the postoperative radiographs. Clinical data indicate that computer-aided rapid prototyping may be of value in minimizing the extra-oral time and possible injury to transplanted tooth during the process of autotransplantation.

Transduction of human catalase mediated by an HIV-1 TAT protein basic domain and arginine-rich peptides into mammalian cells

Antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) have been considered to have a beneficial effect against various diseases mediated by reactive oxygen species (ROS). Although a variety of modified recombinant antioxidant enzymes have been generated to protect against the oxidative stresses, the lack of their transduction ability into cells resulted in limited ability to detoxify intracellular ROS. To render the catalase enzyme capable of detoxifying intracellular ROS when added extracellularly, cell-permeable recombinant catalase proteins were generated. A human liver catalase gene was cloned and fused with a gene fragment encoding the HIV-1 Tat protein transduction domain (RKKRRQRRR) and arginine-rich peptides (RRRRRRRRR) in a bacterial expression vector to produce genetic in-frame Tat-CAT and 9Arg-CAT fusion proteins, respectively. The expressed and purified fusion proteins can be transduced into mammalian cells (HeLa and PC12 cells) in a time- and dose-dependent manner when added exogenously in culture medium, and transduced fusion proteins were enzymatically active and stable for 60 h. When exposed to H(2)O(2), the viability of HeLa cells transduced with Tat-CAT or 9Arg-CAT fusion proteins was significantly increased. In combination with transduced SOD, transduced catalase also resulted in a cooperative increase in cell viability when the cells were treated with paraquat, an intracellular antioxide anion generator. We then evaluated the ability of the catalase fusion proteins to transduce into animal skin. This analysis showed that Tat-CAT and 9Arg-CAT fusion proteins efficiently penetrated the epidermis as well as the dermis of the subcutaneous layer when sprayed on animal skin, as judged by immunohistochemistry and specific enzyme activities. These results suggest that Tat-CAT and 9Arg-CAT fusion proteins can be used in protein therapy for various disorders related to this antioxidant enzyme.

Transduction of Cu,Zn-superoxide dismutase mediated by an HIV-1 Tat protein basic domain into mammalian cells

A human Cu,Zn-superoxide dismutase (Cu,Zn-SOD) gene was fused with a gene fragment encoding the nine amino acid transactivator of transcription (Tat) protein transduction domain (RKKRRQRRR) of HIV-1 in a bacterial expression vector to produce a genetic in-frame Tat-SOD fusion protein. The expressed and purified Tat-SOD fusion protein in Escherichia coli can enter HeLa cells in a time- and dose-dependent manner when added exogenously in a culture media. Denatured Tat-SOD protein was transduced much more efficiently into cells than were native proteins. Once inside the cells, transduced Tat-SOD protein was enzymatically active and stable for 24 h. The cell viability of HeLa cells treated with paraquat, an intracellular superoxide anion generator, was increased by transduced Tat-SOD. These lines of results suggest that the transduction of Tat-SOD fusion protein may be one of the ways to replenish the Cu,Zn-SOD in the various disorders related to this antioxidant enzyme.

Truncated form of importin alpha identified in breast cancer cell inhibits nuclear import of p53

Disruption of the function of tumor suppressor proteins occasionally can be dependent on their subcellular localization. In about 40% of the breast cancer tissues, p53 is found in the cytoplasm as opposed to the nucleus, where it resides in normal breast cells. This means that the regulation of subcellular location of p53 is an important mechanism in controlling its function. The transport factors required for the nuclear export of p53 and the mechanisms of their nuclear export have been extensively characterized. However, little is known about the mechanism of nuclear import of p53. p53 contains putative nuclear localization signals (NLSs) which would interact with a nuclear transport factor, importin alpha. In this report we demonstrate that importin alpha binds to NLSI in p53 and mediates the nuclear import of p53. Reverse transcriptase-polymerase chain reaction and sequencing analyses showed that a truncated importin alpha deleted the region encoding the putative NLS-binding domain of p53, suggesting that it could not bind to NLSs of p53 proteins. Binding of importin alpha to p53 was confirmed by using yeast two-hybrid assay. When expressed in CHO-K1 cells, the truncated importin alpha predominantly localized to the cytoplasm. In truncated importin alpha expressing cells, p53 preferentially localized to cytoplasmic sites as well. A significant increase in the p21(waf1/cip1) mRNA level and induction of apoptosis were also observed in importin alpha overexpressing cells. These results strongly suggest that importin alpha functions as a component of the NLS receptor for p53 and mediates nuclear import of p53.

Aminoacyl-tRNA synthetases and their inhibitors as a novel family of antibiotics

The emergence of multidrug-resistant strains of pathogenic microorganisms and the slow progress in new antibiotic development has led in recent years to a resurgence of infectious diseases that threaten the well-being of humans. The result of many microorganisms becoming immune to major antibiotics means that fighting off infection by these pathogens is more difficult. The best strategy to get around drug resistance is to discover new drug targets, taking advantage of the abundant information that was recently obtained from genomic and proteomic research, and explore them for drug development. In this regard, aminoacyl-tRNA synthetases (ARSs) provide a promising platform to develop novel antibiotics that show no cross-resistance to other classical antibiotics. During the last few years there has been a comprehensive attempt to find the compounds that can specifically target ARSs and inhibit bacterial growth. In this review, the current status in the development of ARS inhibitors will be briefly summarized, based on their chemical structures and working mechanisms.

Identification of three novel mutations and a high frequency of the Arg778Leu mutation in Korean patients with Wilson disease

Four mutations--R778L, A874V, L1083F, and 2304delC--in the copper-transporting enzyme, P-type ATPase (ATP7B), were identified in Korean Patients with Wilson disease. Arg778Leu, the most frequently reported mutation of this enzyme, was found in six of eight unrelated patients studied, an allele frequency of 37.5%, which is considerably higher than those in other Asian populations. The novel single nucleotide deletion, 2304delC, was found in one patient. Since a mutation at cDNA nucleotide 2302 (2302insC) had been previously described, this region of the ATP7B gene may be susceptible to gene rearrangements causing Wilson disease.

A case-control study of ginseng intake and cancer

The effect of ginseng consumption on the risk of cancer was investigated by interviewing 905 pairs of cases and controls matched by age, sex, and date of admission to the Korea Cancer Center Hospital, Seoul, Korea. Of the 905 cases 562 (62%) had a history of ginseng intake compared to 674 of the 905 controls (75%) a statistically significant difference (p less than 0.01). The odds ratio (OR) of cancer in relation to ginseng intake was 0.56 (95% confidence interval (CI), 0.45-0.69). Ginseng extract and powder were shown to be more effective than fresh sliced ginseng, the juice, or tea in reducing the OR. Odds ratios for decreasing levels of ginseng intake were 1.00, 0.58, 0.43 and 0.25 for males and 1.00, 0.81, 0.56 and 0.52 for females. A trend test showed a significant decrease in proportion of cancer cases with increasing frequency of intake for males (p less than 10(-5)) as well as for females (p less than 0.05). Chi-square homogeneity tests also confirmed significant differences between cases and controls for both sexes (p less than 10(-3)). The reliability of recall for ginseng use was assessed by interviewing 180 randomly-selected subjects twice using the same questionnaire. The overall agreement in reported ginseng use between the two interviews was 0.85, and the Kappa value was 0.71 (p less than 0.01). These results strongly support the hypothesis of preventive effects of ginseng on cancer suggested by earlier animal studies.

Use of an anti-low density lipoprotein receptor antibody to quantify the role of the LDL receptor in the removal of chylomicron remnants in the mouse in vivo

Lipoproteins are removed from the plasma by LDL receptor-dependent and -independent pathways. The relative contribution of these has been established for LDL by using modified lipoproteins, but this has not been possible for apoE-rich lipoproteins, such as chylomicron remnants. To do this, we used a monospecific antibody to the rat LDL receptor. The antibody was injected intravenously into mice followed by 125I-lipoproteins. Blood samples were obtained sequentially and radioactivity measured to determine the plasma clearance of the lipoproteins. The animals were then sacrificed and the tissues removed, dried, and the radioactivity measured to determine tissue uptake. An albumin space was also measured to correct for blood trapping. With 125I-human LDL, approximately 50% of the injected dose was cleared in 180 min. This was reduced to 30% by the antibody and this was identical to the disappearance of reductively methylated LDL. This is a lower estimate of LDL-mediated uptake (40%) than in other species. LDL uptake per gram tissue was similar for the liver and the adrenal gland and was approximately 50% LDL receptor-dependent in both tissues. With 125I-chylomicron remnants, clearance was much more rapid with approximately 50% cleared in 5 min. By agarose gel electrophoresis, radioactivity was not transferred from chylomicron remnants to other lipoprotein classes. Chylomicron remnants with label on only apoB or in 3H-cholesterol esters showed a similar pattern. Combining the estimates of the three labeling procedures, approximately 35% of the 30 s and 25% of the 5 min chylomicron remnant disappearance was LDL receptor dependent. The liver, per gram tissue, took up five times as much radioactivity as the adrenal gland. At 5 min, at least 50% of this was LDL receptor-dependent in liver and 65% in adrenal gland. We conclude that the LDL receptor plays a major, and somewhat similar quantitative role in the clearance of both LDL and chylomicron remnants in the mouse. However, at least in the mouse, non-LDL receptor-mediated lipoprotein clearance is quantitatively important and is also very rapid for chylomicron remnants. Thus, for chylomicron remnants, it can easily compensate for LDL receptors if they are blocked or absent. Further, the tissue distribution of lipoprotein uptake may be directed by factors other than LDL receptor density.

The expression of non-clustered protocadherins in adult rat hippocampal formation and the connecting brain regions

Non-clustered protocadherins (PCDHs) are calcium-dependent adhesion molecules which have attracted attention for their possible roles in the neuronal circuit formation during development and their implications in the neurological disorders such as autism and mental retardation. Previously, we found that a subset of the non-clustered PCDHs exhibited circuit-dependent expression patterns in thalamo-cortical connections in early postnatal rat brain, but such patterns disappeared in adulthood. In this study, we identified that the non-clustered PCDHs showed differential expression patterns along the septotemporal axis in the subregions of adult hippocampus and dentate gyrus with topographical preferences. The expressions of PCDH1, PCDH9, PCDH10 and PCDH20 showed septal preferences, whereas the expressions of PCDH8, PCDH11, PCDH17 and PCDH19 showed temporal preferences, suggesting that they play roles in the formation/maintenance of intrahippocampal circuits. PCDHs also exhibited the region-specific expression patterns in the areas connected to hippocampal formation such as entorhinal cortex, lateral septum, and basolateral amygdaloid complex. Furthermore, the expression levels of three PCDHs (PCDH8, PCDH19 and PCDH20) were regulated by the electroconvulsive shock stimulation of the brain in the adult hippocampus and dentate gyrus. These results suggest that non-clustered PCDHs are involved in the maintenance and plasticity of adult hippocampal circuitry.

Anticonvulsant compounds from the wood of Caesalpinia sappan L

80% Aqueous MeOH extracts from the wood of Caesalpinia sappan, which showed remarkable anticonvulsant activity, were fractionated using EtOAc, n-BuOH, and H2O. Among them, the EtOAc fraction significantly inhibited the activities of two GABA degradative enzymes, succinic semialdehyde dehydrogenase (SSADH) and succinic semialdehyde reductase (SSAR). Repeated column chromatographies for the fraction guided by activity test led to the isolation of the two active principal components. Their chemical structures were determined to be sappanchalcone and brazilin based on spectral data. The pure compounds, sappanchalcone (1) and brazilin (2), inactivated the SSAR activities in a dose dependent manner, whereas SSADH was inhibited partially by sappanchalcone and not by brazilin.

Epidemiological study on cancer prevention by ginseng: are all kinds of cancers preventable by ginseng?

In the light of experimental results, two case-control studies and one cohort study in a population of ginseng cultivation area were conducted to confirm whether ginseng has any anticarcinogenic effect on human cancers. All participants were interviewed using a standardised questionnaire to obtain the information on demographics, cigarette smoking, alcohol consumption and ginseng intake. In 905 pairs case-control study, 62% had a history of ginseng intake compared to 75% of the controls, a statistically significant difference (p<0.01). The odds ratio (OR) for cancer in relation to ginseng intake was 0.56. In extended case-control study with 1987 pairs, the ORs for cancer were 0.37 in fresh ginseng extract users, 0.57 in white ginseng extract users, 0.30 in white ginseng extract users, 0.30 in white ginseng powder users, and 0.20 in red ginseng users. Those who took fresh ginseng slices, fresh ginseng juice, and white ginseng tea, however, did not show decrease in the risk. Overall, the risk decreased as the frequency and duration of ginseng intake increased. With respect to the site of cancer, the ORs for cancers of the lip, oral cavity, pharynx, esophagus, stomach, colorectum, liver, pancreas, larynx, lung and ovary were significantly reduced by ginseng intake. Smokers with ginseng intake showed lower ORs for cancers of lung, lip, oral cavity and pharynx and liver than those without ginseng intake. In 5 yr follow- up cohort study conducted in the ginseng cultivation area, Kangwha-eup, ginseng intakers had significantly lower risk than non-intakers. As for the type of ginseng, cancer risk significantly decreased among intakers of fresh ginseng extract, alone or together with other ginseng preparations. Among 24 red ginseng intakers, no cancer death occurred during the follow-up period. The risk for stomach and lung cancers was significantly reduced by ginseng intake, showing a statistically significant dose-response relationship in each follow-up year. In conclusion, Panax ginseng C.A. Meyer has been established as non-organ specific cancer preventive, having dose response relationship. These results warrant that ginseng extracts and its synthetic derivatives should be examined for their preventive effect on various types of human cancers.

Effect of cigarette smoking and alcohol consumption in the etiology of cancers of the digestive tract

This study presents the comparative patterns of risk of selected digestive tract cancers (esophagus, stomach, colon, rectum and liver) for males in relation to cigarette smoking and alcohol drinking, based on the data from case-control studies conducted in the Korea Cancer Center Hospital (KCCH). There was strong positive association between cigarette smoking and esophageal cancer, but none of the other sites was significantly related to cigarette smoking. In esophageal cancer, a dose-dependent effect for cigarette smoking was observed, with the odds ratio ranging from 1.29 for ever smoking up to 1 pack daily to 3.17 for smokers of more than 2 packs per day. The risk declined markedly following cessation of smoking. Cancers of the esophagus, rectum and liver were strongly related to alcohol consumption. Compared with non-drinkers, the OR for heavy drinkers was 9.14 in esophageal cancer, 4.75 in rectal cancer and 2.46 in liver cancer. In cancer of the stomach and colon, however, there was no association with alcohol drinking.

Hydrogen peroxide-mediated Cu,Zn-superoxide dismutase fragmentation: protection by carnosine, homocarnosine and anserine

The fragmentation of human Cu,Zn-superoxide dismutase (SOD) was observed during incubation with H(2)O(2). Hydroxyl radical scavengers such as sodium azide, formate and mannitol protected the fragmentation of Cu,Zn-SOD. These results suggested that *OH was implicated in the hydrogen peroxide-mediated Cu,Zn-SOD fragmentation. Carnosine, homocarnosine and anserine have been proposed to act as anti-oxidants in vivo. We investigated whether three compounds could protect the fragmentation of Cu,Zn-SOD induced by H(2)O(2). The results showed that carnosine, homocarnosine and anserine significantly protected the fragmentation of Cu,Zn-SOD. All three compounds also protected the loss of enzyme activity induced by H(2)O(2). Carnosine, homocarnosine and anserine effectively inhibited the formation of *OH by the Cu,Zn-SOD/H(2)O(2) system. These results suggest that carnosine and related compounds can protect the hydrogen peroxide-mediated Cu,Zn-SOD fragmentation through the scavenging of *OH.

Human neutrophil lactoferrin trans-activates the matrix metalloproteinase 1 gene through stress-activated MAPK signaling modules

It has been proposed that human neutrophil lactoferrin (Lf) could be involved in gene expression as a DNA-binding protein after its translocation into the nucleus. However, the molecular basis of Lf action has not been defined, and Lf-regulated target genes have not been identified. We report here that overexpressed Lf functions as a specific trans-activator of matrix metalloproteinase 1 (MMP1) gene, and that induction of this AP-1-responsive gene is mediated via the stress-activated MAPK signaling modules. Transactivation of the MMP1 promoter by overexpressed Lf requires the presence of an AP-1 binding site. In gel shift experiments, Lf did not interact directly with AP-1-containing fragments of the MMP1 promoter. However, nuclear extracts from Lf-expressing cells contained increased levels of proteins that bound to AP-1 elements. This Lf-induced AP-1 DNA binding activity was reduced by a p38 MAPK inhibitor. Inhibitors of the MEK kinases had little effect on Lf-induced AP-1. However, expression of dominant-negative MKK4 or JNK1 inhibited Lf-induced gene expression. The JNK activity stimulated by Lf correlates with the enhanced AP-1 binding ability. These findings demonstrate that the Lf-induced activation of AP-1 is mediated via JNK and p38 MAPK pathways.