[Impact of bicuspid aortic valve or tricuspid aortic valve on hemodynamics and left ventricular reverse remodeling in patients after transcatheter aortic valve replacement]

Objective: To compare the impact of bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV) on hemodynamics and left ventricular reverse remodeling after transcatheter aortic valve replacement (TAVR). Methods: We retrospectively analyzed the clinical data of patients who underwent TAVR in our hospital from January 2019 to March 2021. Patients were divided into BAV group and TAV group according to aortic contrast-enhanced CT. Each patient was followed up by N-terminal pro B-type natriuretic peptide (NT-proBNP) and echocardiography at four time points, namely before TAVR, 24 hours, 1 month and 6 months after TAVR. Echocardiographic data, including mean pressure gradient (MPG), aortic valve area (AVA), left ventricular ejection fraction (LVEF), left ventricle mass (LVM) and LV mass index (LVMi) were evaluated. Results: A total of 41 patients were included. The age was (75.0±8.6) years, and male patients accounted for 53.7%. There were 19 BAV patients and 22 TAV patients in this cohort. All patients undergoing TAVR using a self-expandable prosthesis Venus-A valve. MPG was (54.16±21.22) mmHg(1 mmHg=0.133 kPa) before TAVR, (21.11±9.04) mmHg at 24 hours after TAVR, (18.84±7.37) mmHg at 1 month after TAVR, (17.68±6.04) mmHg at 6 months after TAVR in BAV group. LVEF was (50.42±13.30)% before TAVR, (53.84±10.59)% at 24 hours after TAVR, (55.68±8.71)% at 1 month after TAVR and (57.42±7.78)% at 6 months after TAVR in BAV group. MPG and LVEF substantially improved at each time point after operation, and the difference was statistically significant (all P<0.05) in BAV group. MPG in TAV group improved at each time point after operation, and the difference was statistically significant (all P<0.05). LVMi was (164.13±49.53), (156.37±39.11), (146.65±38.84) and (134.13±39.83) g/m² at the 4 time points and the value was significantly reduced at 1 and 6 months post TAVR compared to preoperative level(both P<0.05). LVEF in the TAV group remained unchanged at 24 hours after operation, but it was improved at 1 month and 6 months after operation, and the difference was statistically significant (all P<0.05). LVMi in TAV group substantially improved at each time point after operation, and the difference was statistically significant (all P<0.05). NT-proBNP in both two groups improved after operation, at 1 month and 6 months after operation, and the difference was statistically significant (all P<0.05). MPG in TAV group improved better than in BAV group during the postoperative follow-up (24 hours after TAVR: (11.68±5.09) mmHg vs. (21.11±9.04) mmHg, P<0.001, 1 month after TAVR: (10.82±3.71) mmHg vs. (18.84±7.37) mmHg, P<0.001, 6 months after TAVR: (12.36±4.42) mmHg vs. (17.68±6.04) mmHg, P=0.003). There was no significant difference in NT-proBNP between BAV group and TAV group at each time point after operation (all P>0.05). There was no significant difference in paravalvular regurgitation and second prosthesis implantation between the two groups (all P>0.05). Conclusions: AS patients with BAV or TAV experience hemodynamic improvement and obvious left ventricular reverse remodeling after TAVR, and the therapeutic effects of TAVR are similar between BAV and TAV AS patients in the short-term post TAVR.

[Application of indocyanine green-fluorescent imaging technique in planning resection line and real-time surgical navigation in small hepatocellular carcinoma]

Objective: To explore the value of near-infrared technology guided by indolecyanine green(ICG) in planning resection line and real-time surgical navigation in small liver cancer. Methods: From March to September 2015, 11 patients with hepatic tumors received hepatectomy were treated in First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University.There were 5 male and 6 female patients with average age of (55±10)years (range 39-70 years). Among whom, there were 9 cases with hepatocellular carcinoma and 2 cases with colorectal cancer. A near-infrared light camera system was used to detect the liver surfaces before resection, and to plan resection line and surgical specimens. A student's t test was used to compare continuous parametric variables. Results: The ICG-fluorescent imaging and histological examination had been used in the 15 lesions of the 11 patients. Among the 15 lesions, 7 lesions were detected by visual inspections, palpation and ICG-fluorescent imaging, 6 lesions were identified only by ICG-fluorescent imaging, 2 lesions were detected only by ICG-fluorescent imaging after resection.Results of pathologic examination indicated that the total fluorescent type include 5 well differentiated hepatocellular carcinoma and 2 cirrhotic nodule; the partial fluorescent type include 3 moderately differentiated hepatocellular carcinomas and 1 well differentiated hepatocellular carcinomas; the rim fluorescent type included 2 liver metastatic carcinoma and 2 poorly differentiated hepatocellular carcinomas. The average diameter of the tumor size measured by CT was (1.7±0.2)cm, while the average diameter measured by ICG-fluorescent imaging was (1.7±0.3)cm(t=-0.188, P>0.05). Conclusion: Near-infrared technology guided by ICG has important value in planning resection line and real-time surgical navigation in small liver cancer.

Fatigue life enhancement of NiTi rotary endodontic instruments by progressive reciprocating operation

AIM

To evaluate the effect of reciprocating amplitude and progressive angular increment on fatigue life enhancement of NiTi rotary endodontic instruments.

METHODOLOGY

ProTaper F2 instruments were operated in steel artificial canals with both stationary reciprocating (SR) and progressive reciprocating (PR) motions. The SR motions involved symmetric to and fro reciprocation of ± 180(o) , ± 135(o) , ± 90(o) , ± 60(o) and ± 45(o) . The PR motions were ± 45(o) stationary motion superimposed with angular increments of 7(o) , 11(o) , 22.5(o) or 31(o) whenever an instrument completed 1, 10 or 30 reciprocating cycles (rc). The fatigue lives were compared with those under continuous rotation (CR) and a reciprocating operation with a forward 144(o) and backward 72(o) motion proposed by Yared (2008). The statistical significance of these operating modes on fatigue life was examined using one way anova and post hoc Tukey's tests at P = 0.05. Fractographic analysis was also applied to probe the fracture mechanisms of different rotation motions.

RESULTS

Fatigue life increased with decreasing reciprocating amplitude. Operating in the SR increased fatigue life by 355% over that in the CR. Except for the 22.5(o) increment, all PR motions yielded longer fatigue lives than the SR motion. A progressive reciprocating operation with a ± 45(o) reciprocating amplitude and a + 7(o) progressive angular increment every 10 reciprocating cycles (± 45(o) /10rc/+7(o) ) increased fatigue life by 990% over that in the CR motion. In terms of life enhancement over the CR motion, the larger the curvature the less are the differences between different movements. Single crack initiation sites were found in the CR and SR motions, while three crack initiation sites were typical in the ± 45(o) /10rc/+7(o) motion.

CONCLUSIONS

Fatigue life increased with decreasing reciprocating amplitude in stationary reciprocation. A progressive reciprocating operation with ± 45(o) /10rc/+7(o) motion led to significant fatigue life enhancement and multiple fatigue crack initiation in NiTi endodontic instruments.

Catechin stimulates osteogenesis by enhancing PP2A activity in human mesenchymal stem cells

SUMMARY

Using human mesenchymal stem cells, we identified catechin from a panel of herbal ingredients and Chinese traditional compounds with the strongest osteogenic effects. Catechin increased alkaline phosphatase activity, calcium deposition, and mRNA expression of Runx2 and osteocalcin. We further clarified the signaling pathway that catechin mediated to stimulate osteogenesis.

INTRODUCTION

Human mesenchymal stem cells (hMSCs), useful as a species specific cell culture system for studying cell lineage differentiation, were examined as a tool to identify novel herbal ingredients and Chinese traditional compounds for enhancing osteogenesis.

METHODS

Immortalized and primary hMSCs were induced in osteogenic induction medium in the presence of a variety of herbal ingredients and Chinese traditional compounds and osteogenic differentiation was evaluated by histochemical assays and quantitative RT-PCR.

RESULTS

Using immortalized hMSCs, we first identified catechin, 18β-glycyrrhetinic acid, baishao, and danggui with osteogenic properties, which enhanced calcium deposition at the dose without significant cytotoxic effects. Primary hMSCs were then applied for confirming the osteogenic effects of catechin, which increased alkaline phosphatase activity, calcium deposition, and mRNA expression of Runx2 and osteocalcin. We further found the extracellular signal-regulated kinase (ERK) pathway was downregulated upon stimulation with catechin. Catechin increased the level and activity of protein phosphatases 2A (PP2A) that dephosphorylates ERK kinase (MEK) and ERK. Further, PP2A inhibitor, okadaic acid, abolished the effect of catechin-mediated inactivation of ERK and stimulation of osteogenesis. The blocking effect of okadaic acid on osteogenesis was further reversed by PD98059, a specific inhibitor of MEK. Co-immunoprecipitation revealed the association of PP2A to both MEK and ERK.

CONCLUSIONS

These studies propose catechin enhanced osteogenesis by increasing the PP2A level that inhibits the MEK and ERK signaling in hMSCs. These results prove the concept of using hMSCs as a convenient tool for rapid and consistent screening of the osteogenic herbal ingredients and traditional Chinese compounds.

Neuroprotective effect of oral S/B remedy (Scutellaria baicalensis Georgi and Bupleurum scorzonerifolfium Willd) on iron-induced neurodegeneration in the nigrostriatal dopaminergic system of rat brain

AIM OF THE STUDY

S/B remedy prepared from Scutellaria baicalensis Georgi and Bupleurum scorzonerifolfium Willd, two herbals of Xiao-Tsai-Hu-Tang or Sho-Saiko-To (TJ-9), contains active flavonoids. In this study, the protective effect of S/B remedy on iron-induced neurodegeneration was investigated in the nigrostriatal dopaminergic system of rat brain.

MATERIALS AND METHODS

The antioxidative activity of S/B remedy was studied using brain homogenates incubated with ferrous citrate (iron, 1M), S/B remedy, Trolox and melatonin. Furthermore, a Parkinsonian animal model by an intranigral infusion of iron in the anesthetized rats was employed to investigate the protective effect of S/B remedy in the nigrostriatal dopaminergic system.

RESULTS

Our in vitro studies showed that S/B remedy was more potent than melatonin and equal to trolox in inhibiting iron-induced lipid peroxidation of brain homogenates. Our in vivo studies found that oral administration of S/B remedy dose-dependently attenuated iron-elevated lipid peroxidation in the infused substantia nigra (SN) and iron-depleted dopamine levels in the ipsilateral striatum. Furthermore, iron-induced reductions in glutathione (GSH) content and increases in GSSG (oxidized GSH)/GSH ratio in the infused SN were inhibited in S/B remedy-treated rats. Systemic S/B remedy attenuated the iron-induced increases in heme-oxygenase-1 levels and α-synuclein aggregation in the infused SN. Moreover, S/B remedy reduced iron-induced apoptosis via attenuating mitochondrial and endoplasmic reticulum stress. In addition, S/B remedy was anti-inflammatory as indicated by the attenuation of iron-induced elevations in inducible nitric oxide synthase and cyclo-oxygenase II levels as well as glial fibrillary acidic protein (a biological marker of astrocytes) and ED-1 (a protein indicative of activated microglia) levels in the infused SN of S/B remedy-treated rats.

CONCLUSIONS

These findings suggest that oral administration of S/B remedy is protective against iron-induced neurodegeneration in the nigrostriatal dopaminergic system of rat brain. Therefore, S/B remedy may be therapeutically useful for the treatment of CNS neurodegenerative diseases.

Prognostic significance of triple negative breast cancer at tumor size 1 cm and smaller

AIMS

The purpose of this study was to clarify the prognostic significance of triple-negative breast cancer (TNBC) with a tumor size ≤ 1 cm.

MATERIALS AND METHODS

Patients with primary operable breast cancer with a tumor size ≤ 1 cm were enrolled at Changhua Christian Hospital and National Cheng-Kung University Hospital. Tumors negative for ER, PR, and HER-2 were classified as TNBCs and compared with tumors with any receptor positivity (non-TNBC) for disease-free survival (DFS) and cancer-specific survival (CSS).

RESULTS

From 1995 to 2006, a total of 377 patients with tumor size ≤ 1 cm were enrolled. Compared with non-TNBC patients, TNBC patients with a tumor size ≤ 1 cm as a whole or in a lymph node-positive subgroup were not associated with a poorer 5-year DFS and CSS. In lymph node-negative patients (pT1a-bN0M0), TNBC was associated with a poorer 5-year CSS but not DFS. Compared with the hormone receptor-positive, HER-2-negative subgroup, TNBC was associated with poorer DFS and CSS. In the multivariate Cox regression hazard analysis, lymph node invasion was the most important cause of disease recurrence and cancer-specific death.

CONCLUSION

TNBC is very likely an independent risk factor in small (≤1 cm) node-negative invasive breast cancer. With tumors 1 cm and smaller, lymph node invasion was the single most important prognostic factor.

Suitability of boron carriers for BNCT: accumulation of boron in malignant and normal liver cells after treatment with BPA, BSH and BA

Hepatocellular carcinoma remains widely prevalent in tropical Africa and south-east Asia. At present, there are no effective treatments for hepatoma and its prognosis is extremely poor unless the tumor was diagnosed in an early stage and resected before metastasis. Therefore, boron neutron capture therapy (BNCT) may provide an alternative therapy for treatment of hepatocellular carcinoma. In this study, the intracellular concentrations of L-boronophenylalanine (BPA), sodium borocaptate (BSH) and boric acid (BA) were examined in human hepatoma HepG2 and liver Clone 9 cell cultures. With the use of 25 microgB/mL media of BPA, BSH and BA, the intracellular uptake of boron in HepG2 and Clone 9 cells was compared. The suitability of BPA, BSH and BA were further evaluated on the basis of organ-specific boron distribution in normal rat tissues. BPA, BSH and BA were administered via intraperitoneal injection into rats with corresponding boron concentrations of 7, 25, and 25mg/kg body weight, respectively. The accumulation rates of BPA, BSH and BA in HepG2 cells were higher than that of Clone 9 cells. Boron concentration in BPA, BSH and BA treated HepG2 cells were 1.8, 1.5, and 1.6-fold of Clone 9 cells at 4h, respectively. In both HepG2 and Clone 9 cells, although the concentration of boron in BPA-treated cells exceeded that in BA-treated ones, however, cells treated with BPA had similar surviving fraction as those treated with BA after neutron irradiation. The accumulation ratios of boron in liver, pancreas and kidney to boron in blood were 0.83, 4.16 and 2.47, respectively, in BPA treated rats, and 0.75, 0.35 and 2.89, respectively, in BSH treated rats at 3h after treatment. However, boron does not appear to accumulate specifically in soft tissues in BA treated rats. For in situ BNCT of hepatoma, normal organs with high boron concentration and adjacent to liver may be damaged in neutron irradiation. BPA showed high retention in pancreas and may not be a good drug for BNCT of hepatoma. BSH had higher retention in liver but low level in pancreas and spleen appears to be a better candidate BNCT drug for hepatoma. These preliminary results provide useful information on future application of BNCT for hepatoma.

Iron-generated hydroxyl radicals kill retinal cells in vivo: effect of ferulic acid

Siderosis bulbi is vision threatening. An investigation into its mechanisms and management is crucial. Experimental siderosis was established by intravitreous administration of an iron particle (chronic) or FeSO4 (acute). After siderosis, there was a significant dose-responsive reduction in eletroretinogram (a/b-wave) amplitude, and an increase in •OH level, greater when caused by 24 mM FeSO4 than that by 8 mM FeSO4. Furthermore, the FeSO4-induced oxidative stress was significantly blunted by 100 μM ferulic acid (FA). Siderosis also resulted in an excessive glutamate release, increased [Ca++]i, and enhanced superoxide dismutase immunoreactivity. The latter finding was consistent with the Western blot result. Obvious disorganization including loss of photoreceptor outer segments and cholinergic amacrines together with a wide-spreading ferric distribution across the retina was present, which were related to the eletro-retinographic and pathologic dysfunctions. Furthermore, b-wave reduction and amacrine damage were respectively, significantly, dose-dependently, and clearly ameliorated by FA. Thus, siderosis stimulates oxidative stress, and possibly, subsequent excitotoxicity, and calcium influx, which explains why the retina is impaired electro-physiologically and pathologically. Importantly, FA protects iron toxicity perhaps by acting as a free radical scavenger. This provides an approach to the study and treatment of the iron-related disorders such as retained intraocular iron and Alzheimer disease.

Endoplasmic reticulum stress is involved in arsenite-induced oxidative injury in rat brain

The mechanism underlying sodium arsenite (arsenite)-induced neurotoxicity was investigated in rat brain. Arsenite was locally infused in the substantia nigra (SN) of anesthetized rat. Seven days after infusion, lipid peroxidation in the infused SN was elevated and dopamine level in the ipsilateral striatum was reduced in a concentration-dependent manner (0.3-5 nmol). Furthermore, local infusion of arsenite (5 nmol) decreased GSH content and increased expression of heat shock protein 70 and heme oxygenase-1 in the infused SN. Aggregation of alpha-synuclein, a putative pathological protein involved in several CNS neurodegenerative diseases, was elevated in the arsenite-infused SN. From the breakdown pattern of alpha-spectrin, both necrosis and apoptosis were involved in the arsenite-induced neurotoxicity. Pyknotic nuclei, cellular shrinkage and cytoplasmic disintegration, indicating necrosis, and TUNEL-positive cells and DNA ladder, indicating apoptosis was observed in the arsenite-infused SN. Arsenite-induced apoptosis was mediated via two different organelle pathways, mitochondria and endoplasmic reticulum (ER). For mitochondrial activation, cytosolic cytochrome c and caspase-3 levels were elevated in the arsenite-infused SN. In ER pathway, arsenite increased activating transcription factor-4, X-box binding protein 1, C/EBP homologues protein (CHOP) and cytosolic immunoglobulin binding protein levels. Moreover, arsenite reduced procaspase 12 levels, an ER-specific enzyme in the infused SN. Taken together, our study suggests that arsenite is capable of inducing oxidative injury in CNS. In addition to mitochondria, ER stress was involved in the arsenite-induced apoptosis. Arsenite-induced neurotoxicity clinically implies a pathophysiological role of arsenite in CNS neurodegeneration.

Cholinesterase inhibitor affects the amyloid precursor protein isoforms in patients with Alzheimer's disease

An altered platelet ratio of amyloid precursor protein (APP) isoforms might be a diagnostic, predictive, or therapeutic marker for Alzheimer's disease (AD). Our purpose was to test the hypothesis that this ratio might serve as a therapeutic marker for AD patients treated with the cholinesterase inhibitor, galantamine. Thirty-nine patients (mean age 76.6 +/- 9.4 years) with AD were treated with galantamine for 12 weeks. Patients were evaluated at baseline, 4 and 12 weeks by cognitive testing along with a determination of their platelet APP isoform ratio. Western blotting was performed to calculate the APP isoform ratio. At the end of the treatment, cognitive scores significantly improved, and the ratio of the high-molecular-weight (130 kDa) isoform to the low-molecular-weight (110-106 kDa) isoforms increased. These results suggest that cholinesterase inhibition might be involved in APP processing.

Estrogen-metabolizing gene COMT polymorphism synergistic APOE epsilon4 allele increases the risk of Alzheimer disease

Alzheimer disease (AD) is a polygenic multifactorial disorder. Several studies suggested that the neuroprotective effect of estrogen was based on an APOE-dependent mechanism. The goals of the current study were to determine if the genes involved in estrogen metabolism were linked to the risk of AD and find out if there was an interaction between estrogen-metabolizing gene polymorphisms and the APOE epsilon4 allele in the risk of prevalent AD. We investigated 66 patients with AD and 86 age- and gender-matched normal subjects. The polymorphisms of APOE and estrogen-metabolizing genes CYP17, CYP1A1 and COMT were examined. No association was found between each estrogen-metabolizing gene polymorphism and AD. However, the COMT HH genotype and APOE epsilon4 allele had a synergistic effect on the risk of AD. Taking subjects with epsilon4-epsilon4-/HH- as reference, the risk of developing AD in subjects with one epsilon4 allele (epsilon4+epsilon4-/HH-) was 2.6 (95% confidence interval, CI, 0.7- 9.1); however, the risk in subjects with both HH and one epsilon4 (epsilon4+epsilon4-/HH+) increased to 3.6 (95% CI 1.2-10.6). The subjects with homozygous epsilon4 still had the highest risk in developing AD (odds ratio 6.6, 95% CI 0.6-69.6). The p value of the linear trend test for this regression model was 0.004. It is possible that a high metabolism of estrogen by COMT may have reduced the protective effect of estrogen in AD. Further studies to clarify this interaction may improve our understanding of the generic risks for AD.

Effects of 1, 6-Bis[4-(4-amino-3-hydroxyphenoxy)phenyl]diamantane (DPD), a reactive oxygen species and apoptosis inducing agent, on human leukemia cells in vitro and in vivo

1, 6-Bis[4-(4-amino-3-hydroxyphenoxy)phenyl]diamantine (DPD), a new cytostatic and differentiation inducing agent, was found to inhibit the growth of several cancer cell lines in the National Cancer Institute (NCI) Anticancer Drug Screen system. Previously, we demonstrated that DPD inhibited the growth of human colon cancer cell lines both in vitro and in vivo. In this study, we examined the anticancer effects of DPD on two human leukemia cells lines. DPD exerted growth inhibitory activities in vitro against two human leukemia cell lines, the promyeloid line HL-60 and the lymphoblastic line Molt-3. The in vivo effect of tumor growth suppression by DPD was also observed in mouse xenografts. No acute toxicity was observed after an intra-peritoneal challenge of DPD in "severe combined immune-deficiency" (SCID) mice twice a week. The in vitro study showed HL-60 was more sensitive to DPD than Molt-3 through induction of G(0)/G(1) cell-cycle arrest with the appearance of a hypodiploid DNA fraction. The increased superoxide (O(2)(-)), dissipation of the mitochondrial membrane potential, activation of caspase 3, and increase in annexin V binding were evident before apoptosis in DPD-treated cells. The superoxide dismutase 1 (SOD1) mRNA expression was also decreased in DPD-treated HL-60 and Molt-3 cells. Thus, it appeared that inhibition of SOD might be the major cause for the production of cellular superoxide with concomitant decrease of H(2)O(2) in DPD-treated cells. Addition of antioxidant can reduce DPD-induced mitochondrial damage, caspase activation, and annexin V binding in HL-60 cells. The results suggest that the cellular generation of O(2)(-) plays a role in initiating and coordinating DPD-mediated growth arrest and apoptosis of HL-60 cells. Importantly, addition of arsenic trioxide, a compound capable of reactive oxygen species (ROS) generation, significantly enhanced the in vitro activity of DPD. These results suggest that DPD appears to be a potential new modality in human leukemia therapy.

ApoEε4 allele is associated with incidental hallucinations and delusions in patients with AD

Of 135 patients with Alzheimer disease (AD), 56 without psychiatric symptoms at the first visit were followed for a mean period of 51.9 +/- 10.3 months to identify incident psychiatric symptoms. The hazard ratios of ApoE epsilon4 allele in developing psychiatric symptoms were calculated by Cox regression hazard analyses. The presence of the ApoE epsilon4 allele carried a 19.0-fold risk for developing hallucinations and a 3.4-fold risk for delusions.

Alteration of the copy number and deletion of mitochondrial DNA in human hepatocellular carcinoma

Somatic mutations in mitochondrial DNA (mtDNA) have been detected in hepatocellular carcinoma (HCC). However, it remains unclear whether mtDNA copy number and mitochondrial biogenesis are altered in HCC. In this study, we found that mtDNA copy number and the content of mitochondrial respiratory proteins were reduced in HCCs as compared with the corresponding non-tumorous livers. MtDNA copy number was significantly reduced in female HCC but not in male HCC. Expression of the peroxisome proliferator-activated receptor γ coactivator-1 was significantly repressed in HCCs (P<0.005), while the expression of the mitochondrial single-strand DNA-binding protein was upregulated, indicating that the regulation of mitochondria biogenesis is disturbed in HCC. Moreover, 22% of HCCs carried a somatic mutation in the mtDNA D-loop region. The non-tumorous liver of the HCC patients with a long-term alcohol-drinking history contained reduced mtDNA copy number (P<0.05) and higher level of the 4977 bp-deleted mtDNA (P<0.05) as compared with non-alcohol patients. Our results suggest that reduced mtDNA copy number, impaired mitochondrial biogenesis and somatic mutations in mtDNA are important events during carcinogenesis of HCC, and the differential alterations in mtDNA of male and female HCC may contribute to the differences in the clinical manifestation between female and male HCC patients.

Study of in vitro and in vivo effects of 1,6-Bis[4-(4-amino-3-hydroxyphenoxy)phenyl]diamantane (DPD), a novel cytostatic and differentiation inducing agent, on human colon cancer cells

A diamantane derivative 1,6-Bis [4-(4-amino-3-hydroxyphenoxy) phenyl] diamantane (DPD) was found to inhibit the growth of several cancer cell lines in the National Cancer Institute (NCI) Anticancer Drug Screen system. In this study, we examined the in vitro and in vivo effects of DPD on human colon cancer cells. DPD exerted growth inhibitory activities in vitro against three human colon cancer cell lines (Colo 205, HT-29, and HCT-15). DPD-treated cells were arrested at G₀/G₁ as analysed by flow cytometric analysis. The expression of cyclin D was decreased in DPD-treated cells. The differentiation markers of carcinoembryonic antigen and fibronectin were significantly increased in colon cancer cells after treatment with DPD. The epithelium-like brush borders on HT-29 cell surface were also demonstrated at 1 week after withdrawal from DPD treatment. The DPD-induced cell growth inhibition and differentiation were irreversible after removal of DPD. The in vivo effect of tumour growth suppression by DPD was also observed in mouse xenografts. No acute toxicity was observed after an intraperitoneal challenge of DPD in BALB/c-nude mice weekly. These results suggest that DPD appears to be a new potentially less toxic modality of cancer therapy.

The Inhibitory Activities of Recombinant Eglin C Mutants on Kexin and Furin, Using Site-directed Mutagenesis and Molecular Modeling

Mammalian furin and yeast kexin are members of the proprotein convertase family involved in the proteolytic processing of many important precursor proteins. Here the gene coding for the subtilisin inhibitor eglin C was totally synthesized and expressed in E.coli. Substitution of residues at each position P(1), P(2) and P(4) of eglin C with a basic residue using protein engineering could make eglin C a very strong inhibitor for furin (K(i) around 10(-9) mol/L),and even more strong for kexin (K( i ) around 10(-11) mol/ L). Results indicated that (1) A basic residue Lys or Arg at P(1) site is prerequisite for the inhibitor. (2) The second mutation with basic residue at P(4) site drastically increase the inhibitory activity by two orders of magnitude. (3) A basic residue at P(2) site is favorable for the binding to the enzyme, but unfavorable for the stability of the inhibitor, resulting in a temporary inhibition. (4) A hydrophobic residue is preferential at P(3) site. Based on the known crystal structures of subtilisin and eglin C, the interaction between the enzyme and inhibitor was modeled, and their involved residues were predicted which gave a good explanation to the experimental results.

Nonsteroidal anti-inflammatory drugs for treatment of advanced gastric cancer: cyclooxygenase-2 is involved in hepatocyte growth factor mediated tumor development and progression

Surgical treatment of gastric cancer patients is dismal because advanced tumor is often noted at diagnosis. In order to obtain better adjuvant therapy for gastric cancer patients after operation, it is important to understand the mechanism of invasion and metastasis. It is well known that binding of hepatocyte growth factor (HGF) to its receptor (c-Met) regulates gastric cancer progression and metastasis. Recently, HGF was found to up-regulate the expression of cyclooxygenase-2 (COX-2) gene and increase prostaglandin (PG)synthesis in gastric mucosa cells. Over-expression of COX-2 and increased PG secretion have also been found to be involved in the growth and metastasis of gastric cancer. These results together suggest that the signaling pathway of HGF and c-Met may be mediated through ERK2 activation, up-regulation of COX-2 and increased production of PGE(2)in gastric cancer cells. In view of the fact that c-Met is over-expressed in the majority of gastric cancer patients with poor prognosis, COX-2 specific inhibitors may provide beneficial effects in these patients.

2-Methoxyestradiol-induced caspase-3 activation and apoptosis occurs through G(2)/M arrest dependent and independent pathways in gastric carcinoma cells

BACKGROUND

2-Methoxyestradiol (2-Me), one of the estrogen metabolites, has recently been found to possess anti-angiogenesis activity in vivo. Many chemotherapeutic agents, such as taxol, docetaxel, and vinblastine, interact with microtubules and then induce apoptosis. It has been suggested that 2-Me acts on microtubules and results in G(2)/M-cycle arrest of tumor cells. Whether 2-Me induces apoptosis in gastric carcinoma cell lines is not known. Moreover, reactive oxygen species (ROS) produced by 2-Me may be involved in cytotoxicity of tumor cells. Thus, another objective of this study was to evaluate the relation between cell cycle arrest, ROS formation, and caspase activity levels after 2-Me treatment in gastric carcinoma cells.

METHODS

It was determined whether 2-Me directly induced apoptosis in two gastric carcinoma cell lines (SC-M1 and NUGC-3) through caspase-3 and caspase-8 activation and, eventually, induced DNA fragmentation. To clarify the effect of 2-Me-induced G(2)/M arrest in apoptosis, calcium ionophore, A23187, and thapsigargin were used to modulate 2-Me-induced cell cycle responses. Moreover, the role of 2-Me-induced ROS formation in the cell cycle responses also was evaluated.

RESULTS

It was found that 2-Me treatment resulted in G(2)/M-cycle arrest, caspase-8 and caspase-3 activation, and DNA fragmentation. In addition, the 2-Me induced, concomitant increases of peroxide and superoxide anions were correlated with G(2)/M-cycle arrest. Treatment with calcium ionophore A23187 and thapsigargin partially reversed the 2-Me-induced G(2)/M-cycle arrest, with a concomitant decrease in both peroxide and superoxide levels. Moreover, A23187 blocked the 2-Me-induced caspase-3 activation, whereas thapsigargin had no effect. Treatment with calcium channel blockers did not affect 2-Me-induced cell cycle arrest or caspase-3 activation.

CONCLUSIONS

These results suggest that the 2-Me-induced apoptosis of gastric carcinoma cells by DNA fragmentation accompanied caspase activation. Elevation of free radicals was associated with G(2)/M-cycle arrest. The induction of G(2)/M-cycle arrest is not a prerequisite for caspase activation.

Human Ca2+/calmodulin-dependent protein kinase kinase beta gene encodes multiple isoforms that display distinct kinase activity

Ca(+2)/calmodulin-dependent protein kinases (CaMKs) are activated upon binding of Ca(+2)/calmodulin. To gain maximal activity, CaMK I and CaMK IV can be further phosphorylated by an upstream kinase, CaMK kinase (CaMKK). We previously isolated cDNA clones encoding human CaMKK beta isoforms that are heterogeneous in their 3'-sequences (Hsu, L.-S., Tsou, A.-P., Chi, C.-W., Lee, C.-H., and Chen, J.-Y. (1998) J. Biomed. Sci. 5, 141-149). In the present study, we examined the genomic organization and transcription of the human CaMKK beta gene. The human CaMKK beta locus spans more than 40 kilobase pairs and maps to chromosome 12q24.2. It is organized into 18 exons and 17 introns that are flanked by typical splice donor and acceptor sequences. Two major species of transcripts, namely the beta1 (5.6 kilobase pairs) and beta2 (2.9 kilobase pairs), are generated through differential usage of polyadenylation sites located in the last and penultimate exons. Additional forms of CaMKK beta transcripts were also identified that resulted from alternative splicing of the internal exons 14 and/or 16. These isoforms display differential expression patterns in human tissues and tumor-derived cell lines. They also exhibit a distinct ability to undergo autophosphorylation and to phosphorylate the downstream kinases CaMK I and CaMK IV. The differential expression of CaMKK beta isoforms with distinct activity further suggests the complexity of the regulation of the CaMKK/CaMK cascade and an important role for CaMKK in the action of Ca(+2)-mediated cellular responses.

Association analysis of the 5-HT6 receptor polymorphism C267T with depression in patients with Alzheimer's disease

A significant increase of 267C allele of the 5-HT(6) receptor gene has been reported in patients with Alzheimer's disease (AD). Because a deficit in serotonergic neurotransmission is involved in major depression, we tried to find out whether 267C allele is associated with depressive disorders in AD. A psychiatrist interviewed all AD patients and their caregivers for evidence of depression using a Chinese version of the Standard Clinical Interview for DSM-III-R. The difference in the 5-HT(6) genotype or allele distributions between the AD patients with depressive disorders (n = 25) and those without (n = 120) was not significant.

2-Methoxyestradiol-induced caspase-3 activation and apoptosis occurs through G(2)/M arrest dependent and independent pathways in gastric carcinoma cells

BACKGROUND

2-Methoxyestradiol (2-Me), one of the estrogen metabolites, has recently been found to possess anti-angiogenesis activity in vivo. Many chemotherapeutic agents, such as taxol, docetaxel, and vinblastine, interact with microtubules and then induce apoptosis. It has been suggested that 2-Me acts on microtubules and results in G(2)/M-cycle arrest of tumor cells. Whether 2-Me induces apoptosis in gastric carcinoma cell lines is not known. Moreover, reactive oxygen species (ROS) produced by 2-Me may be involved in cytotoxicity of tumor cells. Thus, another objective of this study was to evaluate the relation between cell cycle arrest, ROS formation, and caspase activity levels after 2-Me treatment in gastric carcinoma cells.

METHODS

It was determined whether 2-Me directly induced apoptosis in two gastric carcinoma cell lines (SC-M1 and NUGC-3) through caspase-3 and caspase-8 activation and, eventually, induced DNA fragmentation. To clarify the effect of 2-Me-induced G(2)/M arrest in apoptosis, calcium ionophore, A23187, and thapsigargin were used to modulate 2-Me-induced cell cycle responses. Moreover, the role of 2-Me-induced ROS formation in the cell cycle responses also was evaluated.

RESULTS

It was found that 2-Me treatment resulted in G(2)/M-cycle arrest, caspase-8 and caspase-3 activation, and DNA fragmentation. In addition, the 2-Me induced, concomitant increases of peroxide and superoxide anions were correlated with G(2)/M-cycle arrest. Treatment with calcium ionophore A23187 and thapsigargin partially reversed the 2-Me-induced G(2)/M-cycle arrest, with a concomitant decrease in both peroxide and superoxide levels. Moreover, A23187 blocked the 2-Me-induced caspase-3 activation, whereas thapsigargin had no effect. Treatment with calcium channel blockers did not affect 2-Me-induced cell cycle arrest or caspase-3 activation.

CONCLUSIONS

These results suggest that the 2-Me-induced apoptosis of gastric carcinoma cells by DNA fragmentation accompanied caspase activation. Elevation of free radicals was associated with G(2)/M-cycle arrest. The induction of G(2)/M-cycle arrest is not a prerequisite for caspase activation.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

Isolation and partial characterization of a 46-kd allergen of Bermuda grass pollen

Cyn d Bd46K, a 46-kD component of Bermuda grass (Cynodon dactylon) pollen, had been identified as an allergenic constituent. In the present study two-dimensional (2D) gel electrophoresis illustrated the presence of five acidic isoforms in Cyn d Bd46K, and this molecule was purified by monoclonal antibody (MAb) affinity chromatography for further characterization. Using a digoxigenin-labeled lectin-binding assay, the elucidating protein was disclosed to be a glycoprotein with terminal mannose. The involvement of a carbohydrate moiety in the allergenicity and antigenicity of the elucidated molecule was demonstrated with sodium-periodate-treated Cyn d Bd46K, which reduced binding to its specific MAb and human IgE. We were unable to identify the N-terminal amino acid sequences of Cyn d Bd46K, but some internal amino acid sequences were disclosed by microsequencing some fragments cleaved by Achromobacter protease I and fractionated by reversed-phase column chromatography. The amino acid sequences of 4 identified Cyn d Bd46K internal peptide fragments were found to be 25-71% identical with that of cytochrome c oxidase III from corn grass pollen. The present study provided important information for future experiments on the molecular cloning of the elucidated allergen.

Accumulation of mitochondrial DNA deletions in human oral tissues -- effects of betel quid chewing and oral cancer

Accumulation of mitochondrial DNA (mtDNA) mutations in human tissues has been associated with intrinsic aging and environmental insult. Recently, mtDNA mutations have been detected in various tumors, including head and neck tumors. However, the factors affecting the occurrence and accumulation of mtDNA deletions in tumor tissues are poorly understood. In Taiwan, betel quid chewing is a major risk factor for oral cancer. Using polymerase chain reaction (PCR) techniques, we examined large-scale deletions of mtDNA in 53 pairs of tumor and non-tumor oral tissues from the patients with or without betel quid chewing history. The results revealed that irrespective of the history of betel quid chewing, the incidences of the 4977bp deletion and other deletions of mtDNA were lower in the tumor portion as compared with the non-tumor portion. The average proportions of the 4977bp deleted mtDNA in the tumor tissues of the betel quid chewers and non-betel quid chewers were 13- and 5-fold, respectively, lower than those in the corresponding non-tumor tissues. Moreover, the average proportion of 4977bp deleted mtDNA was significantly higher (P<0.05) in the non-tumor oral tissues of the patients with betel quid chewing history than that of the patients without the history of betel quid chewing. These results suggest that betel quid chewing may increase mtDNA mutation in human oral tissues and that accumulation of mtDNA deletions and subsequent cytoplasmic segregation of these mutations during cell division could be an important contributor to the early phase of oral carcinogenesis.

Tie-1 tyrosine kinase is an independent prognostic indicator for invasive breast cancer

Receptor tyrosine kinases are known to be involved in the growth, progression and metastasis of solid tumors. We investigated the relationship between tie-1 expression and progression of invasive ductal breast carcinoma with immunohistochemical analysis. Tie-1 protein was detected in the microvessel endothelial cells and cytoplasm of tumor cells. The tumor size and stage were significantly associated with the expression of tie-1, which portends a worse 5-year disease-free status (39.3% v 59.2%, p = 0.07) and overall survival rate (67.3% v 93%, p = 0.02) than those without tie-1 expression. Multivariate analysis demonstrated that larger tumor size, presence of lymph node metastasis and tie-1 expression were independent prognostic parameters, both in 5-year disease-free survival and overall survival. Patients with lymph node metastases and tie-1 expression had the worst 5-year disease-free survival (0%) and overall survival (42.4%) compared to those without tie-1 expression (50.2%, 85%). In lymph node negative patients, those without tie-1 expression had better 5-year disease-free survival and overall survival (72.9%, 100%) compared to those with tie-1 expression (65.5%, 87.7%). We conclude that tie-1 expression is an independent prognostic factor for invasive ductal breast carcinoma, adversely affecting survival of breast cancer patients with positive nodes to a significant extent.

Molecular characterization of an anti-epilepsy peptide from the scorpion Buthus martensi Karsch

For a long time Asian scorpion Buthus martensi Karsch (BmK) has been used in Chinese traditional medicine to cure many diseases of nervous system. Here we report the purification and characterization of a pharmacologically active neurotoxin from the scorpion BmK. This toxin had little toxicity in mice and insects but was found to have an anti-epilepsy effect in rats, and is thus named as BmK anti-epilepsy peptide (BmK AEP). Its amino-acid sequence was determined by lysylendopeptidase digestion, Edman degradation and mass spectrographic analysis. Based on the determined sequence, the gene coding for this peptide was also cloned and sequenced by the 3' and 5' RACE methods. It encodes a precursor of 85 amino-acid residues including a signal peptide of 21 residues, a mature peptide of 61 residues and three additional residues Gly-Lys-Lys at the C-terminus. The additional Gly sometimes followed by one or two basic residues is prerequisite for the amidation of its C-terminus. C-terminal amidation was also verified by the molecular-mass determination of BmK AEP. This anti-epilepsy peptide toxin shares homology with other depressant insect toxins. The remarkable difference between them was mainly focused at residues 6, 7 and 39; these residues might relate to the unique action of BmK AEP.

Immunohistochemical studies of Na+/I- symporter in human thyroid tissues--a correlation with clinical thyroid scintigraphy

BACKGROUND

Thyroid Na+/I- symporter (NIS) is thought to play an important role in iodide uptake in thyrocytes. We hypothesize that there is correlation between the expression of NIS protein in the normal and diseased thyroid tissues and their clinical thyroid scintigraphy.

METHODS

Twenty-seven patients, aged from 21 to 81, were studied from the surgical department of a tertiary referral center. Ten patients were with papillary carcinoma, 5 with follicular carcinoma, 5 with follicular adenoma, 5 with nodular goiter and 2 with Graves' disease. All the carcinoma patients underwent total thyroidectomy while others had lobectomy or subtotal thyroidectomy. The thyroid tissue sections prepared for study were stained with polyclonal hNIS antibody (SS Chiang, Ohio).

RESULTS

Most of the nodular goiters were negatively stained except 2 samples that showed weak signal focally. All cases with follicular adenoma or follicular carcinoma were negative for NIS expression, while some with papillary carcinoma were stained positive at sporadic follicles with weak signal. The thyroid tissue of Graves' disease was stained positive for NIS expression.

CONCLUSIONS

Thyroid tissues with hypofunctioning nodules displayed significantly reduced or undetectable level of NIS expression. It correlated well with pre-operative thyroid scans.

Expression of cyclooxygenase-2 in prostate adenocarcinoma and benign prostatic hyperplasia

Elevated expression of cyclo-oxygenase (COX)-2 has been found in several human cancers, including prostate adenocarcinoma. To evaluate the potential prognostic role of COX-2 in prostate cancer, we assessed the expression of COX-2 in benign prostatic hyperplasia (BPH) and prostate cancer samples employing immunohistochemistry. COX-2 was over-expressed in 15 out of 18 (83%) prostate cancer samples whereas it was detected in only 22% (4 of 18) paired benign tissues. The intensity of immunostaining correlated with the tumor grading. In addition, COX-2 was expressed in 7 of the 22 (32%) BPH samples examined. The significance a COX-2 expression in the BPH samples is not known at present. This data suggest that COX-2 is over-expressed in prostate cancer and COX-2 inhibitors may be useful in combination chemotherapy or chemoprevention for prostate cancer.

The neuroprotective effects of phytoestrogens on amyloid beta protein-induced toxicity are mediated by abrogating the activation of caspase cascade in rat cortical neurons

Amyloid beta protein (Abeta) elicits a toxic effect on neurons in vitro and in vivo. In present study we attempt to elucidate the mechanism by which Abeta confers its neurotoxicity. The neuroprotective effects of phytoestrogens on Abeta-mediated toxicity were also investigated. Cortical neurons treated with 5 microm Abeta-(25-35) for 40 h decreased the cell viability by 45.5 +/- 4.6% concomitant with the appearance of apoptotic morphology. 50 microm kaempferol and apigenin decreased the Abeta-induced cell death by 81.5 +/- 9.4% and 49.2 +/- 9.9%, respectively. Abeta increased the activity of caspase 3 by 10.6-fold and to a lesser extent for caspase 2, 8, and 9. The Abeta-induced activation of caspase 3 and release of cytochrome c showed a biphasic pattern. Apigenin abrogated Abeta-induced cytochrome c release, and the activation of caspase cascade. Kaempferol showed a similar effect but to a less extent. Kaempferol was also capable of eliminating Abeta-induced accumulation of reactive oxygen species. These two events accounted for the remarkable effect of kaempferol on neuroprotection. Quercetin and probucol did not affect the Abeta-mediated neurotoxicity. However, they potentiated the protective effect of apigenin. Therefore, these results demonstrate that Abeta elicited activation of caspase cascades and reactive oxygen species accumulation, thereby causing neuronal death. The blockade of caspase activation conferred the major neuroprotective effect of phytoestrogens. The antioxidative activity of phytoestrogens also modulated their neuroprotective effects on Abeta-mediated toxicity.

Protein-tyrosine kinase and protein-serine/threonine kinase expression in human gastric cancer cell lines

Protein kinases play key roles in cellular functions. They are involved in many cellular functions including; signal transduction, cell cycle regulation, cell division, and cell differentiation. Alterations of protein kinase by gene amplification, mutation or viral factors often induce tumor formation and tumor progression toward malignancy. The identification and cloning of kinase genes can provide a better understanding of the mechanisms of tumorigenesis as well as diagnostic tools for tumor staging. In this study, we have used degenerated polymerase-chain-reaction primers according to the consensus catalytic domain motifs to amplify protein kinase genes (protein-tyrosine kinase, PTK, and protein-serine/threonine kinase, PSK) from human stomach cancer cells. Following amplification, the protein kinase molecules expressed in the gastric cancer cells were cloned into plasmid vectors for cloning and sequencing. Sequence analysis of polymerase-chain-reaction products resulted in the identification of 25 protein kinases, including two novel ones. Expression of several relevant PTK/PSK genes in gastric cancer cells and tissues was further substantiated by RT-PCR using gene-specific primers. The identification of protein kinases expressed or activated in the gastric cancer cells provide the framework to understand the oncogenic process of stomach cancer.

Cloning, expression and chromosomal localization of human Ca2+/calmodulin-dependent protein kinase kinase

A human cDNA clone encoding the calcium/calmodulin-dependent protein kinase kinase (CaMKK) was isolated by RT-PCR amplification of the fragment corresponding to the conserved kinase catalytic domain followed by rapid amplification of cDNA ends and cDNA library screening. Compilation of nucleotide sequencing data yielded a consensus cDNA sequence of 1.9 kb with an open reading frame of 1,251 nucleotides in length which translates to a polypeptide of 417 amino acids (47 kd). It showed significant homology to the rat brain CaMKK isozymes. The human CaMKK, which was expressed as a Flag-tagged protein in human non-small cell lung cancer H- 1299 cells followed by immunoprecipitation with anti-Flag antibody, was shown to phosphorylate recombinant human CaMK I in a calcium/CaM-dependent fashion. Northern blot analysis revealed that human CaMKK is ubiquitously expressed, with brain showing the highest level of expression. The CaMKK gene is localized to human chromosome 12. The presence of cDNA clones with divergent 3' terminal sequences suggests a family of CaMKK variants which may arise from alternative splicing.

Male predominance in hepatocellular carcinoma: new insight and a possible therapeutic alternative

Hepatocellular carcinoma is one of the most common cancers in the world. The male to female ratio is 3-6 to 1 in patients with hepatocellular carcinoma. Although steroid hormones and receptors have been examined extensively for their role in the growth regulation of hepatocellular carcinoma, the direct stimulation of hepatocellular carcinoma by steroid hormones still awaits elucidation. On the other hand, clinical trials using antagonists for steroid hormones to treat hepatocellular carcinoma were found to be mostly ineffective. Recently it has been found that 2-methoxyestradiol - an estrogen metabolite - is effective in growth inhibition of various tumor cells as well as in angiogenesis inhibition. Since estrogen is metabolized in the liver, it is conceivable that females with menstruation cycles have more estrogen metabolized in their liver, consequently more 2-methoxyestradiol produced which could inhibit tumor growth in situ. We propose that the low incidence and mortality of hepatocellular carcinoma found in females may have resulted from the high levels of 2-methoxyestradiol produced in the liver during their reproductive years. Consequently, the growth of hepatocellular carcinoma in females is delayed significantly as compared to males. The potential of using 2-methoxyestradiol for treatment of patients with hepatocellular carcinoma after resection of tumor should be explored.

In vitro and in vivo suppression of growth of rat liver epithelial tumor cells by antisense oligonucleotide against protein kinase C-alpha

BACKGROUND/AIMS

It has been hypothesized that liver stem cells may be activated and proliferate upon liver injury and may participate in the development of liver cancer. GP7TB, a rat liver epithelial tumor cell line, possesses characteristics of liver stem-like cells and can develop into a tumor in syngeneic Fischer 344 rat. We found that protein kinase C-alpha (PKC-alpha) is overexpressed in GP7TB cells. The importance of PKC-alpha for this liver tumor cell was elucidated.

METHODS

Antisense oligonucleotide (ODN) was applied to suppress the production of PKC-alpha in GP7TB cells in vitro and in vivo. Cell viability was measured by acid phosphatase assay. The cellular levels of PKC-alpha and Bcl-2 were monitored by Western-blot analysis. Activation of nuclear factor NF-kappaB was analyzed by electrophoretic mobility shift assay. Cell cycle phase distribution was monitored by FACScan. Cell apoptosis was detected by TUNEL assay and histochemical staining of tumor tissue sections. The in vivo experiment was conducted by implanting tumor mass of GP7TB in the liver of F-344 rat and continuous delivery of the ODN by a mini-osmotic pump.

RESULTS

Antisense ODN effectively suppressed the level of PKC-alpha that resulted in the decrease of Bcl-2 and nuclear NF-kappaB. The cumulative viable cells also decreased dramatically for the antisense-treated group. FACScan showed that the cells were arrested at early S-phase. These cells in turn went into apoptosis without completing a cell cycle. It was found that growth of the tumor was suppressed efficiently by antisense ODN. Cell apoptosis was found in the orthotopic tumor. The normal liver cells were not affected.

CONCLUSIONS

A lethal effect of depressing the level of PKC-alpha in GP7TB cells and success in suppressing orthotopic tumor growth in vivo suggests that PKC-alpha antisense ODN would be a promising therapeutic agent for some liver cancers.

Comparison of 2-methoxyestradiol-induced, docetaxel-induced, and paclitaxel-induced apoptosis in hepatoma cells and its correlation with reactive oxygen species

BACKGROUND

Previously, the authors observed that paclitaxel treatment of hepatoma cells resulted in differential cytotoxicity. Whether other antimicrotubule agents (docetaxel and 2-methoxyestradiol) are more effective than paclitaxel is not clear. Moreover, whether the modulation of reactive oxygen species (ROS) is involved in the drug-induced growth inhibition of hepatoma cells is not known.

METHODS

The authors examined the effects of 2-methoxyestradiol, paclitaxel, and docetaxel on HepG2, Hep3B, HA22T/VGH, and Hepa1-6 hepatoma cell lines. The parameters examined included cell viability, cell membrane permeability, cell cycle distribution, DNA fragmentation, and ROS generation.

RESULTS

Docetaxel and paclitaxel inhibited the growth of hepatoma cells at submicromolar concentrations, whereas that of 2-methoxyestradiol was within a micromolar range. This drug-induced growth inhibition was cell cycle dependent. 2-Methoxyestradiol-treated (10-50 microM) cells resulted in G2/M block prior to apoptosis. High dose (0.1 microM) docetaxel- and paclitaxel-treated cells resulted in a G2/M arrest followed by generation of polyploidy or apoptosis; however, low dose (0.01 microM) treatment induced apoptosis without G2/M arrest. The low dose effect was more significant in docetaxel-treated cells than in paclitaxel-treated cells. Although these antimicrotubule agents increased the formation of ROS, antioxidant treatment did not block drug-induced cell cycle and growth inhibition effects.

CONCLUSIONS

The current results suggest that the growth inhibition of hepatoma cells induced by 2-methoxyestradiol, paclitaxel, and docetaxel was mediated through G2/M-phase arrest, caspase activation, and DNA fragmentation. The drug-induced apoptosis was independent of ROS formation. Docetaxel was more effective than paclitaxel in killing hepatoma cells. The potential of using 2-methoxyestradiol and docetaxel for the treatment of patients with hepatoma is worthy of further study.

Prognostic significance of heat shock protein-27 expression in hepatocellular carcinoma and its relation to histologic grading and survival

BACKGROUND

The expression of heat shock protein-27 (HSP-27) has been detected in some human tumors. In this study the authors investigated HSP-27 expression in patients with hepatocellular carcinoma (HCC) and examined its prognostic significance.

METHODS

Expression of HSP-27 was studied in 58 HCC and adjacent noncancerous liver tissues by immunohistochemical stain. The relation between its expression and eight known prognostic factors was evaluated.

RESULTS

Of the 58 HCC tissues studied, the presence of HSP-27 was demonstrated in 45 tissues (77.6%); low expression (</= 25%) was demonstrated in 17 tissues and high expression (> 25%) was demonstrated in 28 tissues. A significantly higher distribution of HSP-27 expression in HCC tissues compared with adjacent noncancerous liver tissues was obtained (P < 0.0001). Patients with high HSP-27 expression had a significantly higher histologic tumor grade than those with low HSP-27 expression (P = 0.001). The 5-year disease free survival rate of patients with high HSP-27 expression was 21.4% versus 59.3% for patients with low HSP-27 expression (P < 0.001). A similar relation was observed with overall survival (33.3% vs. 64. 8%; P = 0.009). HSP-27 expression was also identified to be a significant and powerful prognostic indicator for disease free survival (odds ratio = 2.25; P = 0.034) and for overall survival (odds ratio = 2.72; P = 0.015).

CONCLUSIONS

The current study data suggest that HSP-27 expression is a powerful prognostic indicator and is related to histologic grade and survival of patients with HCC.

Prognostic significance of heat shock protein-27 expression in hepatocellular carcinoma and its relation to histologic grading and survival

BACKGROUND

The expression of heat shock protein-27 (HSP-27) has been detected in some human tumors. In this study the authors investigated HSP-27 expression in patients with hepatocellular carcinoma (HCC) and examined its prognostic significance.

METHODS

Expression of HSP-27 was studied in 58 HCC and adjacent noncancerous liver tissues by immunohistochemical stain. The relation between its expression and eight known prognostic factors was evaluated.

RESULTS

Of the 58 HCC tissues studied, the presence of HSP-27 was demonstrated in 45 tissues (77.6%); low expression (</= 25%) was demonstrated in 17 tissues and high expression (> 25%) was demonstrated in 28 tissues. A significantly higher distribution of HSP-27 expression in HCC tissues compared with adjacent noncancerous liver tissues was obtained (P < 0.0001). Patients with high HSP-27 expression had a significantly higher histologic tumor grade than those with low HSP-27 expression (P = 0.001). The 5-year disease free survival rate of patients with high HSP-27 expression was 21.4% versus 59.3% for patients with low HSP-27 expression (P < 0.001). A similar relation was observed with overall survival (33.3% vs. 64. 8%; P = 0.009). HSP-27 expression was also identified to be a significant and powerful prognostic indicator for disease free survival (odds ratio = 2.25; P = 0.034) and for overall survival (odds ratio = 2.72; P = 0.015).

CONCLUSIONS

The current study data suggest that HSP-27 expression is a powerful prognostic indicator and is related to histologic grade and survival of patients with HCC.

Adamantyl maleimide induced changes in adhesion molecules and ROS are involved in apoptosis of human gastric cancer cells

BACKGROUND

We have previously found that N-1-adamantyl maleimide (AMI) inhibited the growth of SC-M1 tumors in vitro and in vivo. The cytotoxicity of AMI on SC-M1 was accompanied by a decrease of adherent cells and the suppressive effect was associated with conformational changes in cell membrane protein. In order to determine the cellular targets of AMI in human gastric cancer SC-M1 cells, we examined AMI-induced changes in the levels of adhesion molecules CD29 (beta 1 integrin) and CD54 (ICAM-1) and GSH. In addition, we also analyzed changes of apoptosis markers such as annexin V binding to membrane and caspase 3 activity in SC-M1 cells after treatment with AMI.

MATERIALS AND METHODS

Changes in CD29, CD54, annexin V binding and GSH levels were examined using FITC-conjugated antibodies or fluorescence probes and flowcytometry. Caspase 3 activity was assayed with spectrofluorometry.

RESULTS

We found that the expression of CD29 and CD54 on SC-M1 was decreased and the caspase 3 activity was increased during the early apoptosis induced by AMI. Moreover, it was found that the GSH content of the cell was depleted within 30 minutes and then recovered.

CONCLUSION

These results suggest that the cell membrane proteins, such as adhesion molecules (CD29, CD54) and intracellular GSH, were the targets of AMI on SC-M1 cells. Since these membrane alterations were prior to apoptosis they may have transduced a death signal to SC-M1 cells.

Tumor necrosis factor gene polymorphism and septic shock in surgical infection

OBJECTIVES

To evaluate the relationship of the genotype distribution of the tumor necrosis factor (TNF)-alpha polymorphism with regard to the plasma TNF-alpha concentration and the development of septic shock as well as mortality of infected patients in a surgical intensive care unit (SICU).

DESIGN

A total of 112 postoperative critically ill infected patients were prospectively enrolled.

SETTING

SICU of a tertiary university-affiliated medical center.

PATIENTS

Patients who were consecutively admitted to the SICU because of surgical infection with sepsis.

INTERVENTION

Blood sampling.

MEASUREMENTS AND MAIN RESULTS

Blood sample was obtained 24 hrs after intensive care unit (ICU) admission or within 2 hrs after the onset of septic shock to determine the plasma TNF-alpha level and to analyze the genotype of the biallelic polymorphism of the TNF-alpha.

RESULTS

The allele frequency of the TNF2 in our infected ICU patients was 12%. Forty-two (37.5%) patients admitted fulfilled the criteria of septic shock during their ICU stay. Patients carrying the TNF2 allele were not more likely to develop septic shock, nor did they have a higher mortality rate. In the patients with septic shock, those carrying the TNF2 allele had a significantly higher mortality rate than those with the homozygous TNF1 genotype (92% vs. 62%, p < .05). In those who developed septic shock, the TNF2 allele was significantly associated with higher TNF levels.

CONCLUSION

In patients admitted to SICU with surgical infection, the frequency of TNF2 allele was higher than in the general population. SICU patients with TNF2 allele did not show a higher incidence of developing septic shock, nor was there a higher baseline TNF-alpha level after infection. However, once septic shock had developed, the mortality rate was higher in those patients carrying the TNF2 allele.

Enhanced hydroxychavicol-induced cytotoxic effects in glutathione-depleted HepG2 cells

Hydroxychavicol (HC) is the major safrole urinary metabolite in rats and humans. The cytotoxic potential of HC in metabolically competent cells has yet to be studied. HC alone was slightly toxic to HepG2 cells. However, the cytotoxicity increased significantly (P<0.05) when HepG2 cells were pretreated with buthionine sulfoximine (BSO), suggesting that endogenous glutathione participates in HC-induced cytotoxicity. Addition of catalase or N-acetylcysteine prevented the BSO plus HC-mediated cytotoxicity. HC also increased 8-hydroxy-2'-deoxyguanosine formation and apoptosis in BSO-pretreated HepG2 cells and this increase could also be suppressed by catalase. These data suggest that BSO pretreatment enhanced HC-induced cytotoxic effects in HepG2 cells, which are related to oxidative DNA damage.

Human gastric cancer kinase profile and prognostic significance of MKK4 kinase

Alterations of protein tyrosine kinase are often associated with uncontrolled cell growth and tumor progression. Knowledge of the overall expression pattern of tyrosine kinases should prove beneficial in understanding the signaling pathways involved in gastric cancer oncogenesis and in providing possible biomarkers for gastric cancer progression. To establish a general tyrosine-kinase expression profile, degenerated polymerase chain reaction primers designed from the consensus catalytic kinase motifs were used to amplify protein tyrosine kinase molecules from gastric cancer tissues. We observed more than 50 tyrosine and serine/threonine kinases from matching pairs of gastric cancer tissue and normal mucosa. Based on this new kinase profile information, we selected the MKK4 gene for further immunohistochemical studies. Statistical analysis of MKK4 protein expression and clinicopathological features indicated that MKK4 kinase expression could serve as a significant prognostic factor for relapse-free survival and for overall survival. We demonstrated a simple and sensitive method for establishing protein tyrosine-kinase expression profiles of human gastric cancer tissues as well as for discovering novel and useful clinical biomarkers from such kinase expression profiles.

Increase of mitochondria and mitochondrial DNA in response to oxidative stress in human cells

Mitochondrial respiratory function is impaired in the target tissues of patients with mitochondrial diseases and declines with age in various human tissues. It is generally accepted that respiratory-chain defects result in enhanced production of reactive oxygen species and free radicals in mitochondria. Recently, we have demonstrated that the copy number of mitochondrial DNA (mtDNA) is increased in the lung tissues of elderly human subjects. The mtDNA copy number was suggested to be increased by a feedback mechanism that compensates for defects in mitochondria harbouring mutated mtDNA and a defective respiratory system. However, the detailed mechanism remains unclear. In this study, we treated a human lung fibroblast cell line, MRC-5, with H(2)O(2) at concentrations of 90-360 microM. After the treatment for 24-72 h, we found that cells were arrested at G(0) and G(1) phases but that mitochondrial mass and mtDNA content were significantly increased in a concentration- and time-dependent manner. Moreover, the oxidative stress induced by buthionine sulphoximine was also found to cause an increase in mitochondrial mass of the treated cells. Increased uptake of a vital mitochondrial dye Rhodamine 123 and enhanced tetrazolium [MTT, 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] reduction revealed that the mitochondria increased by H(2)O(2) treatment were functional. In addition, the increase in the mitochondrial mass was also observed in cell-cycle-arrested cells induced by mimosine, lovastatin and genistein. Taken together, these findings suggest that the increase in mitochondrial mass and mtDNA content are the early molecular events of human cells in response to endogenous or exogenous oxidative stress through cell-cycle arrest.

Increase of mitochondria and mitochondrial DNA in response to oxidative stress in human cells

Mitochondrial respiratory function is impaired in the target tissues of patients with mitochondrial diseases and declines with age in various human tissues. It is generally accepted that respiratory-chain defects result in enhanced production of reactive oxygen species and free radicals in mitochondria. Recently, we have demonstrated that the copy number of mitochondrial DNA (mtDNA) is increased in the lung tissues of elderly human subjects. The mtDNA copy number was suggested to be increased by a feedback mechanism that compensates for defects in mitochondria harbouring mutated mtDNA and a defective respiratory system. However, the detailed mechanism remains unclear. In this study, we treated a human lung fibroblast cell line, MRC-5, with H(2)O(2) at concentrations of 90-360 microM. After the treatment for 24-72 h, we found that cells were arrested at G(0) and G(1) phases but that mitochondrial mass and mtDNA content were significantly increased in a concentration- and time-dependent manner. Moreover, the oxidative stress induced by buthionine sulphoximine was also found to cause an increase in mitochondrial mass of the treated cells. Increased uptake of a vital mitochondrial dye Rhodamine 123 and enhanced tetrazolium [MTT, 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] reduction revealed that the mitochondria increased by H(2)O(2) treatment were functional. In addition, the increase in the mitochondrial mass was also observed in cell-cycle-arrested cells induced by mimosine, lovastatin and genistein. Taken together, these findings suggest that the increase in mitochondrial mass and mtDNA content are the early molecular events of human cells in response to endogenous or exogenous oxidative stress through cell-cycle arrest.

Prognostic significance of heat shock protein-27 expression in hepatocellular carcinoma and its relation to histologic grading and survival

BACKGROUND

The expression of heat shock protein-27 (HSP-27) has been detected in some human tumors. In this study the authors investigated HSP-27 expression in patients with hepatocellular carcinoma (HCC) and examined its prognostic significance.

METHODS

Expression of HSP-27 was studied in 58 HCC and adjacent noncancerous liver tissues by immunohistochemical stain. The relation between its expression and eight known prognostic factors was evaluated.

RESULTS

Of the 58 HCC tissues studied, the presence of HSP-27 was demonstrated in 45 tissues (77.6%); low expression (</= 25%) was demonstrated in 17 tissues and high expression (> 25%) was demonstrated in 28 tissues. A significantly higher distribution of HSP-27 expression in HCC tissues compared with adjacent noncancerous liver tissues was obtained (P < 0.0001). Patients with high HSP-27 expression had a significantly higher histologic tumor grade than those with low HSP-27 expression (P = 0.001). The 5-year disease free survival rate of patients with high HSP-27 expression was 21.4% versus 59.3% for patients with low HSP-27 expression (P < 0.001). A similar relation was observed with overall survival (33.3% vs. 64. 8%; P = 0.009). HSP-27 expression was also identified to be a significant and powerful prognostic indicator for disease free survival (odds ratio = 2.25; P = 0.034) and for overall survival (odds ratio = 2.72; P = 0.015).

CONCLUSIONS

The current study data suggest that HSP-27 expression is a powerful prognostic indicator and is related to histologic grade and survival of patients with HCC.

The gene cloning and sequencing of Bm-12, a chlorotoxin-like peptide from the scorpion Buthus martensi Karsch

According to the known amino acid sequence of Bm-12, a short chain insect neurotoxin from the venom of the scorpion Buthus martensi Karsch (BmK) with considerable primary sequence homology to chlorotoxin, the gene specific primers were designed and synthesized for 3' and 5'RACE (Rapid Amplification of cDNA Ends). The two partial cDNA fragments obtained by 3' and 5'RACE were cloned and sequenced, and the full length cDNA sequence of Bm-12 was then completed by overlapping these two partial cDNA sequences. The predicted amino acid sequence consists of 59 amino acid residues including a putative signal peptide of 24 residues and a mature toxin of 35 residues. The predicted amino acid sequence of Bm-12 was almost consistent with the determined, different only in one residue at position 27, Lys was replaced by Gly. Based on the determined cDNA sequence, and using the total DNA isolated from the scorpion venom glands as a template, the genomic DNA of Bm-12 was also amplified by PCR and sequenced. The genomic DNA sequence revealed an intron of 93 bp present within the signal peptide region.

No association between butyrylcholinesterase K-variant and Alzheimer disease in Chinese

Increased butyrylcholinesterase (BChE) activity has been reported to be associated with the formation of amyloid plaques and neurofibrillary tangles and may consequently be involved in the pathogenesis of Alzheimer disease (AD). Because the catalytic activity of BChE-K variant is reduced by one-third compared with non-variant, we speculated that BChE-K variant has a protective effect on AD. However, Lehmann et al. [1997] reported a synergistic effect between the genes for BChE-K variant and apolipoprotein E (ApoE) epsilon 4, which increases the risk for late onset AD. In the present study, we tested 89 Chinese AD patients and 101 Chinese controls and found no evidence of association between BCHE-K and AD of either early or late onset (age > 65 years). No evidence of a synergistic effect was found between the BCHE-K variant and APOE epsilon 4 in this study. Our data suggest that BChE-K variant has no modifying effect on the pathogenesis of AD. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:167-169, 2000.

Serum interleukin-10 but not interleukin-6 is related to clinical outcome in patients with resectable hepatocellular carcinoma

OBJECTIVE

To evaluate the clinical significance of preoperative serum levels of interleukin-10 (IL-10) and interleukin-6 (IL-6) in patients with resectable hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

IL-10 is an immunosuppressive factor and IL-6 is a multifunctional cytokine that plays a role in host defense mechanisms. Both have been reported to be related to the disease prognosis in some human solid tumors. Their role in human HCC has not been investigated.

METHODS

Preoperative serum samples of 67 patients with HCC who underwent potentially curative resection and 27 normal healthy donors were assayed. Levels of IL-10 and IL-6 were determined by enzyme-linked immunosorbent assay. The clinical significance of serum IL-10 and IL-6 was evaluated and compared with conventional clinicopathologic factors.

RESULTS

Levels of IL-10 and IL-6 were significantly higher in patients with HCC than in healthy subjects. There was no correlation between IL-10 and IL-6 levels. Tumor resection resulted in a decrease in IL-10 and IL-6 levels. On univariate analysis, patients with high IL-10 levels had a worse disease-free survival, but IL-6 levels had no correlation with the disease-free survival. Multivariate analysis identified IL-10 levels as a predictor of postresectional outcome, in addition to the well-established clinical risk factors.

CONCLUSIONS

In patients with HCC, the preoperative serum IL-10 level is related to the clinical outcome. IL-10 may play an important role in the progression of HCC.

Genomic organization of three novel toxins from the scorpion Buthus martensi Karsch that are active on potassium channels

The cDNA and genomic DNA of three novel toxins from the scorpion Buthus martensi Karsch that are active on K(+) channels, designated BmKTX (where KTX is kaliotoxin), BmTX1 and BmTX2, were cloned and sequenced. On the basis of their known amino acid sequences, gene-specific primers for 3' and 5' rapid amplification of cDNA ends (RACE) were designed and synthesized. By overlapping the two partial cDNA sequences obtained by 3' and 5' RACE, their full-length cDNA sequences were completed. BmKTX encodes a signal peptide of 22 amino acid residues and a mature toxin of 38 residues, whereas BmTX1 and BmTX2 encode signal peptides of 20 and 21 residues respectively and a mature toxin of 38 residues for each. Their cDNA-deduced amino acid sequences were totally consistent with those determined except that the C-terminus of BmKTX had an additional Gly residue, which was removed during post-translational processing and was indispensable for the amidation of its C-terminal Lys residue. In addition, the first deduced amino acid for both BmTX1 and BmTX2 is Gln instead of pyro-Glu in the reported toxins, which obviously also undergoes post-translational processing. The genomic DNA species of these three toxins were also amplified by PCR, then cloned and sequenced. They all consisted of two exons disrupted by a small single intron. All of these introns were inserted within the signal peptides at position -6 for BmKTX and at position -5 for both BmTX1 and BmTX2 upstream of the mature toxins, and consisted of 87, 87 and 80 bp respectively.