[Application of three methods in occupational health risk assessment of automobile 4S shop].

Objective: To choose various occupational health risk assessment of the mature methods at home and abroad respectively occupational health risk assessment was carried out on the 4s stores, to explore different risk assessment methods on the 4 s shop the applicability of the occupational health risk assessment. Methods: Chemical was applied on the harmful factors of occupational health risk assessment technology guideline in the composite index method, quantitative cancer risk assessment method using the guidelines for the harmful factors of occupational health risk assessment of chemical technology of composite index method, quantitative cancer risk assessment method, international commission on mining and metals (ICMM) occupational health risk assessment quantitative method and the occupational-disease-inductive operation classification to evaluate chemical factors in 4S store, Combined with on-site occupational health investigation to compare with the result of risk assessment and analysis of international mining and metals (ICMM) committee occupational health risk assessment quantitative method and the occupational-disease-inductive operation classification of 4S store to evaluate chemical factors, combined with on-site occupational health investigation comparison and analysis the result of the risk assessment. Results: Except for 6 times, the results of ICMM matrix method and comprehensive index method were consistent, which were all higher than job classification. The other results were job classification of >of ICMM matrix method >comprehensive index method or job classification of >of ICMM matrix method. Conclusion: When the concentration of occupational-disease-inductive factors is lower than 1/2 limit, the risk assessment results tend to be ICMM quantitative >composite index method >operation classification. When the occupational-disease-inductive factors were involved with triphenyl, the quantitative non-carcinogenic risk assessment method was more likely to reach the conclusion that the occupational health risk was unacceptable.

Immediate effects of coloured overlays on the reading performance of preschool children with an autism spectrum disorder using eye tracking.

BACKGROUND: Coloured overlays have often been used to improve reading performance in preschool children with an autism spectrum disorder (ASD), however, previous evidence shows conflicts in its application. AIMS: To investigate the immediate effects of coloured overlays on reading performance using eye tracking in preschool children with ASD and their typical development (TD) counterparts closely matched by chronological age. METHODS: Forty participants with ASD (n = 20) or TD (n = 20) were recruited by convenience sampling and asked to read aloud numbers randomly arranged on paper. Participants' ocular performance (fixation duration, fixation count, total visit duration), reading speed and number of errors were recorded by eye tracker and digital stopwatch respectively throughout testing with and without coloured overlays. RESULTS: The findings show that coloured overlays had no significant immediate effect in improving ocular performance and reading speed of children with ASD or TD, although individual improvements were identified in some children with ASD. CONCLUSIONS: Use of coloured overlays may not be useful to improve reading and ocular performance in children with ASD in one single occasion. The potential effect on reading ability of using coloured overlays repetitively for a longer period needs further investigation.

[Application of Mohs microsurgery in nasal basal cell carcinoma].

Objective: To discuss the application of Mohs microsurgery in nasal and facial basal cell carcinoma (BCC) and analyze the pathological and clinical features. Methods: The clinical data of 127 patients who were diagnosed by pathology as nasal and facial BCC in Qilu Hospital of Shandong University from January 2010 to January 2015 were retrospectively analysed. The value of Mohs microsurgery was discussed and the nasal & facial sites of BCC lesions, clinical and histopathology features were summarized. Results: The proportion of male and female was 1.27︰1 in 127 patients, the ages ranged from 27 to 91 years. The top three inflicted area in nasal and facial was followed by nasal dorsum, nasal root and upper lip.The most frequent clinical type was nodular ulcerative type.The most common pathological type was nodular and pigmented. Routine surgical resection was performed in 62 cases (48.8%) while Mohs micrographic surgery in 38 cases (29.9%). Follow-up duration was 37 months on average. Local recurrence occurred in 5 cases in routine surgical resection group while there was no recurrence in Mohs micrographic surgery group. There was no distant metastasis in all cases. Conclusions: There are few specific clinical manifestation in nasal & facial BCC. Surgical treatment is prefered, especially by Mohs micrographic surgery, because it can strictly control the scope of surgical resection and obtain malformation repairment as well as beauty in nasal and facial region.

Changes in cerebrovascular reactivity in healthy adults after acute exposure to high altitude.

OBJECTIVE: To study changes in the cerebrovascular reactivity (CVR) at different altitude area in healthy adults. SUBJECTS AND METHODS: CVR was tested using transcranial Doppler combined with CO2 inhalation, near-infrared spectroscopy (NIRS) was used to detect the regional cerebral oxygen saturation (rScO2). Blood samples were collected, and the vasoactive substances in serum were detected using the enzyme-linked immunosorbent assay. In this study, 59 healthy adults were divided into 3 groups: low altitude group, medium altitude group and high altitude group. All the indicators in low altitude group were tested at 24h before departure and after arrival from Beijing (at an altitude of 44.4 m) to Xining (at a medium altitude of 2200 m). Then, after resting for 48h, all the indicators were tested at 24h and 48h after arrival from Xining (at a medium altitude of 2200 m) to Yushu Jiegu town (at a high altitude of 3700 m) together with those at the medium altitude. Intergroup comparisons were made for the subjects in the three altitudes. RESULTS: There was an increase in the CVR in low altitude group after acute exposure to high altitude, and the difference was significant (CVR: 1.94re was vs. 0.91±0.53, p<0.001); the CVR index was increased, and the difference was significant [cerebrovascular reserve index (CVRI): 3.65he CVR vs. 1.37e CVR, p<0.001]; the rScO2 level was decreased with the increase of altitude, and the difference was significant [(66.78±4.61)% vs. (70.29±4.52)%, p<0.001]. The levels of vasoactive substances in low altitude group were decreased after acute exposure to high altitude compared with those before exposure: NO: [(79.14±9.54) µmol/L vs. (58.01±9.93) µmol/L, p<0.001]; serum eNOS level was increased, and the difference was significant [(77.23±6.20) pg/ml vs. (65.07±9.82) pg/ml, p<0.001]; EPO: [(84.68±13.16) pg/ml vs. (65.01±5.92) pg/ml, p<0.001]; VEGF: [(71.91±11.62) pg/ml vs. (54.92±11.86) pg/ml, p<0.001]; sFlt: [(384.18±42.73) pg/ml vs. (320.62±78.96) pg/ml, p<0.001]. There was also an increase in CVR in medium altitude group after acute exposure to high altitude, and the difference was significant [CVR: 2.00±0.79 vs. 0.91±0.66, p<0.001]; the difference of CVRI was significant [3.83±0.67 vs. 1.67±0.87, p<0.001]; rScO2 was slightly decreased with the increase of altitude, and the difference was not statistically significant [(67.53±4.61) % vs. (69.63±5.59) %, p<0.001]. Before exposure to high altitude area, the levels of NO, NOS, EPO, VEGF, and sFlt in low and medium altitude groups were higher than those in high altitude group. CVR level of subjects at different altitudes was negatively related to the ScO2 (r=-0.91) but positively related to NO and NOS levels (rs=0.89, r=0.75); CVR was moderately related to VEGF and EPO (rs=0.45, r=0.42). rScO2 was positively related to RBC, HB and VEGF levels (r=0.89, r=0.75, rs=0.86), but had a moderately negative correlation with NO and NOS levels (rs=-0.52, r=-0.57). CONCLUSIONS: After subjects at a low altitude are exposed to high altitude rapidly, CVR is increased, RBC and vasoactive substances in serum, such as NO, eNOS, and EPO, are dramatically increased, VEGF is increased first and then decreased, sFlt-1 level is increased gradually, and rScO2 level is gradually decreased with the increase of altitude, indicating the local brain anoxia of subjects at a high altitude.

Effects of methotrexate on the quality of oocyte maturation in vitro.

Methotrexate (MTX), an antifolate drug, is widely used for clinical treatment of malignancies and ectopic pregnancy. Many studies have documented that MTX has strong side-effects on rapidly dividing somatic cells. However, its side-effects on female reproductive cells have not been widely reported. Combined with in vitro culture, two-photon fluorescence imaging and three-dimensional reconstruction, this study analyzed the effects of MTX on oocyte maturation time, chromosome arrangement, karyotype, spindle morphology, and the localization of microtubule organizing centers (MTOCs). Compared with a control group (84%), the rate of germinal vesical breakdown in the MTX group dropped to 73% (P < 0.05). The rate of the first polar body extrusion in the MTX group (53%) was also below the control group (63%; P < 0.05). The rate of abnormal chromosomal arrangement in the MTX group was 60%, but 24% in the control group (P < 0.05). The matured oocyte karyotypes showed 20 univalents in both control and MTX groups, while point-shaped DAPI signals were detected in the MTX group. The rate of abnormal spindle in the MTX group was 49%, but 17% in the control group (P < 0.05). MTOCs in oocytes with normal spindles concentrated at the poles, while MTOCs in oocytes with abnormal spindles were scattered around the poles or in the ooplasm. MTX changes the structures of chromosomes and spindles, potentially by interfering with DNA methylation. The above results indicate a basis for understanding negative effects of MTX on oocyte maturation quality, and provide information for the clinical application of MTX in female patients.

The comparison of the rejuvenation effects on the skin of Wistar rats between 10600 nm CO2 fractional laser and retinoic acid.

OBJECTIVE: The fractional laser and topical retinoic acid treatment have been applied for skin rejuvenation; however, the possible molecular mechanism of promoting remodeling of dermis is not clearly. Here we aimed to compare the effects of 10600 nm CO2 fractional laser and topical retinoic acid formulation on the skin collagen proliferation of Wistar rats, and to further explore the possible molecular mechanism of promoting remodeling of dermis. MATERIALS AND METHODS: The hair on the back of Wistar rats was removed, and the back was divided equally into four regions with the cross-streaking method: A (the control group), B (the retinoic acid group), C (retinoic acid and fractional laser combination treatment group), and D (the fractional laser group). Specimens were collected at 3rd day and in 1-8 weeks after CO2 fractional laser irradiation; then they were used for detection of the changes of dermis thickness and content of hydroxyproline in the four regions of the rats' back. Real-time PCR method was used to detect the dynamic changes of the expression level of type III procollagen mRNA and the expression levels of miR-29a, Akt and transforming growth factor-ß (TGF-ß) mRNA at 3rd week in the skin tissue of Wistar rats. RESULTS: The thickness of dermis, content of hydroxyproline and expression level of type III procollagen mRNA in the treatment groups (B, C, and D) were found all significantly increased compared with those in the control group (A) (p<0.05); at 3rd week, up-regulation of Akt and TGF-ß mRNA expression and down-regulation of miR-29a mRNA expression were observed in the treatment groups (B, C, and D). The difference in the combination treatment group (C) was the most significant (p<0.05). CONCLUSIONS: These results demonstrate that retinoic acid formulation and CO2 fractional laser both can promote collagen proliferation and reconstruction, with the skin rejuvenation efficacy in group C > group D > group B. miR-29a/Akt/TGF-ß signal pathways may play a certain role in the promotion of collagen synthesis and proliferation.

A new method for estimating the number of non-differentially expressed genes.

Control of the false discovery rate is a statistical method that is widely used when identifying differentially expressed genes in high-throughput sequencing assays. It is often calculated using an adaptive linear step-up procedure in which the number of non-differentially expressed genes should be estimated accurately. In this paper, we discuss the estimation of this parameter and point out defects in the original estimation method. We also propose a new estimation method and provide the error estimation. We compared the estimation results from the two methods in a simulation study that produced a mean, standard deviation, range, and root mean square error. The results revealed that there was little difference in the mean between the two methods, but the standard deviation, range, and root mean square error obtained using the new method were much smaller than those produced by the original method, which indicates that the new method is more accurate and robust. Furthermore, we used real microarray data to verify the conclusion. Finally we provide a suggestion when analyzing differentially expressed genes using statistical methods.

Nerve growth factor regulates the expression of vascular endothelial growth factor in human HaCaT keratinocytes via PI3K/mTOR pathway.

Decades of research have provided the data to confirm the hypothesis that there is bidirectional communication between the central nervous system and the immune system in psoriasis pathogenesis, but the contribution of the cutaneous neural system remains underexplored. In this study, we evaluated the molecular mechanisms by which nerve growth factor (NGF) regulates hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) production. The mRNA and protein levels of VEGF secretion from HaCaT cells by NGF were increased in a concentration-dependent manner. In addition, the NGF- induced increase in VEGF is accompanied by an increase in HIF-1α, but not HIF-2α or HIF-1ß. However, this increase is abrogated by pretreatment with a mammalian target of rapamycin (mTOR) inhibitor rapamycin. Pharmacologic inhibitors of the Trk tyrosine kinase, PI-3 kinase, and mTOR pathways prevent NGF-stimulated increases in HIF-1α and VEGF. Mutation of the siRNA-mediated silencing of HIF-1α expression blocks NGF-induced increases in VEGF transcription. Our study indicates that NGF regulates the expression of VEGF through the PI3K/mTOR signaling pathway in human HaCaT keratinocytes.

A method for simultaneously delineating multiple targets in 3D-FISH using limited channels, lasers, and fluorochromes.

Many studies have suggested a link between the spatial organization of genomes and fundamental biological processes such as genome reprogramming, gene expression, and differentiation. Multicolor fluorescence in situ hybridization on three-dimensionally preserved nuclei (3D-FISH), in combination with confocal microscopy, has become an effective technique for analyzing 3D genome structure and spatial patterns of defined nucleus targets including entire chromosome territories and single gene loci. This technique usually requires the simultaneous visualization of numerous targets labeled with different colored fluorochromes. Thus, the number of channels and lasers must be sufficient for the commonly used labeling scheme of 3D-FISH, "one probe-one target". However, these channels and lasers are usually restricted by a given microscope system. This paper presents a method for simultaneously delineating multiple targets in 3D-FISH using limited channels, lasers, and fluorochromes. In contrast to other labeling schemes, this method is convenient and simple for multicolor 3D-FISH studies, which may result in widespread adoption of the technique. Lastly, as an application of the method, the nucleus locations of chromosome territory 18/21 and centromere 18/21/13 in normal human lymphocytes were analyzed, which might present evidence of a radial higher order chromatin arrangement.

5-Azacytidine induces early stage apoptosis and promotes in vitro maturation by changing chromosomal construction in murine oocytes.

As an anticancer drug, 5-azacytidine (5-AzaC) has been widely used to treat various cancers. To investigate the effect of 5-AzaC on mouse oocytes cultured in vitro, we have performed morphological and molecular biology studies to examine the behavior of chromosomes and oocyte development. In 5-AzaC-treated oocytes, chromosomes were decondensed and unstable. The mRNA levels of Caspase3, Caspase8, and Caspase9 increased with the occurrence of early stage apoptosis in oocytes following 5-AzaC treatment. Furthermore, the mRNA levels of Gdf9 and Bmp15 also increased with the corresponding morphological changes in 5-AzaC-treated oocytes. In conclusion, 5-AzaC not only induced early apoptosis through both extrinsic and intrinsic pathways, but also had a positive effect on the developmental competence of mouse oocytes during in vitro maturation. These effects may be due to changes in chromosomal construction induced by DNA hypomethylation.

Three-dimensional quantitative analysis of chromosomes in the oocytes of aging mice during meiosis I in vitro.

The mechanism of senescence is very complicated and can involve formation of chromosome abnormalities and a decline in female fertility. In this study, 3-D visualization of fluorescently labeled chromosomes in oocytes from aging and pubertal mice during in vitro maturation was done with a two-photon laser scanning microscope. Differences between aging and pubertal groups at various maturation stages were analyzed quantitatively in terms of chromosomal morphology, shape, and spatial arrangement. Compared with the pubertal group, the chromosomal morphology of oocytes from aging mice changed: both the mean volume and the mean surface area of chromosomes increased by approximately 20% (P < 0.05) at prometaphase and metaphase of meiosis I (considered to be the weakly condensed folded form of the chromosomes). Furthermore, at these stages, the shape of the chromosomal array became rounder (roundness factor increased by approximately 10%; P < 0.001) and the adhesion among chromosomes became more severe (P < 0.001) at approximately the same stages. Additionally, trends over time for both chromosomal morphology and shape were quite distinct between oocytes from aging and pubertal mice. Interestingly, trends for mean distance were similar; therefore, aging did not seem to influence chromosome movement toward the metaphase plate. These morphologic results should be useful to study age-related degradation of oocyte quality and to interpret results derived from molecular biology.

Performance of homeostasis model assessment and serum high-sensitivity C-reactive protein for prediction of isolated post-load hyperglycaemia.

AIMS: To evaluate whether homeostasis model assessment and high-sensitivity C-reactive protein improve the prediction of isolated post-load hyperglycaemia. METHODS: The subjects were 1458 adults without self-reported diabetes recruited between 2006 and 2010. Isolated post-load hyperglycaemia was defined as fasting plasma glucose < 7 mmol/l and 2-h post-load plasma glucose ≥ 11.1 mmol/l. Risk scores of isolated post-load hyperglycaemia were constructed by multivariate logistic regression. An independent group (n = 154) was enrolled from 2010 to 2011 to validate the models' performance. RESULTS: One hundred and twenty-three subjects (8.28%) were newly diagnosed as having diabetes mellitus. Among those with undiagnosed diabetes, 64 subjects (52%) had isolated post-load hyperglycaemia. Subjects with isolated post-load hyperglycaemia were older, more centrally obese and had higher blood pressure, HbA(1c), fasting plasma glucose, triglycerides, LDL cholesterol, high-sensitivity C-reactive protein and homeostasis model assessment of insulin resistance and lower homeostasis model assessment of ß-cell function than those without diabetes. The risk scores included age, gender, BMI, homeostasis model assessment, high-sensitivity C-reactive protein and HbA(1c). The full model had high sensitivity (84%) and specificity (87%) and area under the receiver operating characteristic curve (0.91), with a cut-off point of 23.81; validation in an independent data set showed 88% sensitivity, 77% specificity and an area under curve of 0.89. CONCLUSIONS: Over half of those with undiagnosed diabetes had isolated post-load hyperglycaemia. Homeostasis model assessment and high-sensitivity C-reactive protein are useful to identify subjects with isolated post-load hyperglycaemia, with improved performance over fasting plasma glucose or HbA(1c) alone.

Inverse correlation between caveolin-1 expression and clinical severity in psoriasis vulgaris.

OBJECTIVE: This study investigated the clinical significance of expression of caveolin-1--a plasma membrane protein involved in caveola formation, endocytosis, signal transduction and angiogenesis--in the pathogenesis of psoriasis vulgaris. METHODS: A total of 20 patients with psoriasis vulgaris and 20 healthy volunteers were recruited. The expressions of caveolin-1, Ki-67 (marker of cell proliferation) and CD34 (marker of angiogenesis) in skin biopsies were detected by immunohistochemistry, and the level of caveolin-1 protein was quantified by Western blotting. Clinical severity was assessed using the Psoriasis Area and Severity Index (PASI) score. Correlations between caveolin-1 expression and psoriasis severity, cell proliferation and angiogenesis were analysed using the Spearman rank correlation test. RESULTS: Expression of caveolin-1 was significantly lower in psoriasis samples than in healthy skin samples. In psoriasis lesions, the level of caveolin-1 expression was inversely correlated with the severity of psoriasis, cell proliferation and angiogenesis. CONCLUSIONS: The level of caveolin-1 expression seems to be related to the clinical severity of psoriasis, and may play a role in the abnormal keratinocyte hyperplasia and angiogenesis seen in this condition.

A numerical investigation of the effect of vertex geometry on localized surface plasmon resonance of nanostructures.

Advances in nanofabrication and nano-scale measurement methods now allow for fabrication of highly detailed nanometer-scale topographic features. As geometric features greatly impact the formation of an electromagnetic field in response to incident light, this in turn calls for the study of the effects of new features of nanostructures on their performance in applications such as localized surface plasmon resonance (LSPR) sensing. This paper studies the effects of vertex features of a single nanostructure on its LSPR properties. A general relationship between the LSPR spectra and the vertex features of a nanoparticle is established. The results of electrodynamics calculations show that a delta-star with a relatively small vertex angle exhibits a bigger resonant wavelength than one with a large vertex angle. Moreover, the sensing performance initially increases, and then decreases as angular size of the vertices increases, with a turning point of 30 degrees. It is also shown that for nanostars with different numbers of vertices, the resonant wavelength undergoes a blue shift and the sensing performance grows poorer as the number of vertices increases. A regular vertex angle of 30 degrees displays the greatest figure of merit (FOM) value for LSPR applications, approximately 9.5 RIU(-1).

Effects of vertex truncation of polyhedral nanostructures on localized surface plasmon resonance.

Polyhedral nanostructures are widely used to enable localized surface plasmon resonance (LSPR). In practice, vertices of such structures are almost always truncated due to limitations of nanofabrication processes. This paper studies the effects of vertex truncation of polyhedral nanostructures on the characteristics of LSPR sensing. The optical properties and sensing performance of triangular nanoplates with truncated vertices are investigated using electrodynamics analysis and verified by experiment. The experimental results correlated with simulation analysis demonstrate that the fabricated triangular nanoplate array has a truncation ratio, defined as the length of truncation along an edge of the triangle over the edge length, of approximately 12.8%. This significantly influences optical properties of the nanostructures, resulting in poorer sensing performance. These insights can be used to guide the design and fabrication of nanostructures for high performance LSPR sensors.

Adhesiveness of dental resin-based restorative materials investigated with atomic force microscopy.

This study aimed to show that the polymerization contraction of dental methacrylate-based materials, when used as adhesives on hard substrate, produces voids at the material-substrate interface. This phenomenology is closely related with the nanoleakage and the sealing ability of these materials. One prime/bond system, three restorative composite resins, and one orthodontic bonding system were cured by using mirror-like glass slides as a compliance-free reference substrate. The adhesive surface was analyzed by atomic force microscopy, and the polymerization contraction of bulk material was tested by laser beam-scanning method. Nanoperiodic structure of three-dimensional (3D) images, section analysis, and roughness characteristics (R(a) and R(z)) indicated that polymerization contraction produced voids at the interface. When the adhesive surface was exposed to oral simulating fluids (water, ethanol, and lactic acid solutions), hydrolytic degradation involved some hundreds of nanometers in depth. In visible light-cured (VLC) materials, the interface porosity decreased when an irradiation pause ( approximately 2 min) was carried out during gelation.

Polymerization of dental composite resins using plasma light.

Five visible light-cured composite resins used as restoration or adhesive materials in dentistry, were irradiated with high energy plasma light (1300 mW/cm2), and contraction, rate of contraction, irradiation-induced temperature were analysed. A comparison was carried out with the same materials irradiated with a conventional halogen light (400 mW/cm2). The exposure to the photoactivating lights was either continuously or sequentially in three or more intervals with 10 min between intervals. Comparing the lengths of exposure of both lights, which induced the same contraction in a given material, it was found that the exposure length to the plasma light was greatly reduced, when compared with the exposure length of the halogen light (1:10). Frequently, the final contraction of plasma-irradiated materials was lower, whereas the rate of contraction, as indicated by the linear dimensional variation curves obtained by laser beam scanning method, did not show significant differences between the two lights. The temperature increase induced by plasma light on the material did not exceed the temperature induced by conventional light.

Inhibitory mechanisms of tea polyphenols on the ultraviolet B-activated phosphatidylinositol 3-kinase-dependent pathway.

In this study, we investigated the effect of tea polyphenols, (-)-epigallocatechin-3-gallate or theaflavins, on UVB-induced phosphatidylinositol 3-kinase (PI3K) activation in mouse epidermal JB6 Cl 41 cells. Pretreatment of cells with these polyphenols inhibited UVB-induced PI3K activation. Furthermore, UVB-induced activation of Akt and ribosomal p70 S6 kinase (p70 S6-K), PI3K downstream effectors, were also attenuated by the polyphenols. In addition to LY294002, a PI3K inhibitor, pretreatment with a specific mitogen-activated protein/extracellular signal-regulated protein kinases (Erks) kinase 1 inhibitor, U0126, or a specific p38 kinase inhibitor, SB202190, blocked UVB-induced activation of both Akt and p70 S6-K. Pretreatment with LY294002 restrained UVB-induced phosphorylation of Erks, suggesting that in UVB signaling, the Erk pathway is mediated by PI3K. Moreover, pretreatment with rapamycin, an inhibitor of p70 S6-K, inhibited UVB-induced activation of p70 S6-K, but UVB-induced activation of Akt did not change. Interestingly, UVB-induced p70 S6-K activation was directly blocked by the addition of (-)-epigallocatechin-3-gallate or theaflavins, whereas these polyphenols showed only a weak inhibition on UVB-induced Akt activation. Because PI3K is an important factor in carcinogenesis, the inhibitory effect of these polyphenols on activation of PI3K and its downstream effects may further explain the anti-tumor promotion action of these tea constituents.

Transactivation of the epidermal growth factor receptor is involved in 12-O-tetradecanoylphorbol-13-acetate-induced signal transduction.

The mechanism of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion is still not well understood even though it is thought to be related to the protein kinase C/mitogen-activated protein kinase/AP-1 pathway. Recently, TPA was also found to induce epidermal growth factor receptor (EGFR) activity. Here, we investigated whether the EGFR is a necessary component for TPA-induced signal transduction associated with tumor promotion. We demonstrated that potent inhibitors of the EGFR, PD153035 and AG1478, blocked TPA-induced phosphorylation of extracellular signal-regulated kinases (ERKs), AP-1 activity, and cell transformation. Egfr gene deficiency blocked TPA-induced ERK activity and AP-1 binding activity. The blocking of the ectodomain of the EGFR by a monoclonal antibody depressed TPA-induced ERK activity and AP-1 DNA binding activity. The use of a neutralizing antibody for heparin-binding EGF, one of the ligands of EGFR, blocked TPA-induced phosphorylation of ERKs. BB-94, a potent inhibitor of matrix metalloproteinases, which are activators of ectodomain shedding of EGFR ligands, also blocked TPA-induced ERK activity, AP-1 DNA binding, and cell transformation but had no effect on EGF-induced signal transduction. Anti-EGFR, anti-heparin-binding EGF, and BB-94 each blocked TPA-induced EGFR phosphorylation, but only anti-EGFR could block EGF-induced EGFR phosphorylation. Based on these results, we conclude that the EGFR is required for mediating TPA-induced signal transduction. EGFR transactivation induced by TPA is a mechanism by which the EGFR mediates TPA-induced tumor promotion-related signal transduction.

Inositol hexaphosphate inhibits ultraviolet B-induced signal transduction.

Inositol hexaphosphate (InsP6) has an effective anticancer action in many experimental models in vivo and in vitro. Ultraviolet B (UVB) radiation is believed to be responsible for many of the carcinogenic effects related to sun exposure, and alteration in UVB-induced signal transduction is associated with UVB-induced carcinogenesis. Here we report the effects of InsP6 on UVB-induced signal transduction. InsP6 strongly blocked UVB-induced activator protein-1 (AP-1) and NF-kappaB transcriptional activities in a dose-dependent manner. InsP6 also suppressed UVB-induced AP-1 and nuclear factor kappaB (NF-kappaB) DNA binding activities and inhibited UVB-induced phosphorylation of extracellular signal-regulated protein kinases (Erks) and c-Jun NH2-terminal kinases (JNKs). Phosphorylation of p38 kinases was not affected. InsP6 also blocked UVB-induced phosphorylation of IkappaB-alpha, which is known to result in the inhibition of NF-kappaB transcriptional activity. InsP6 does not block UVB-induced phosphotidylinositol-3' (PI-3) kinase activity, suggesting that the inhibition of UVB-induced AP-1 and NF-kappaB activities by InsP6 is not mediated through PI-3 kinase. Because AP-1 and NF-kappaB are important nuclear transcription factors that are related to tumor promotion, our work suggests that InsP6 prevents UVB-induced carcinogenesis by inhibiting AP-1 and NF-kappaB transcription activities.