Identification of microRNAs associated with lymphangiogenesis in human gastric cancer

PURPOSE

Lymphatic metastasis is a primary cause of gastric cancer-related death, yet factors governing tumor cell lymphatic metastasis have not been fully elucidated. MicroRNAs (miRNAs) are a recently discovered class of regulatory, non-coding RNAs, some of which are involved in gastric cancer progression. However, little is known about which miRNA contributes to the lymphatic metastasis in human gastric cancer. This prompted us to find the significant miRNAs associated with lymphangiogenesis in human gastric cancer.

METHODS

We screened vascular endothelial growth factor C (VEGF-C) expression in several gastric cancer cell lines as well as in the immortalized human gastric mucosal cell line GES-1, by real-time reverse transcriptase PCR (qRT-PCR). The gastric cancer cell lines MKN-45 and SGC-7901, which have commonly been cultured with human lymphatic endothelial cells (HLECs) in vitro, promoted tube formation of HLECs following transformation with a VEGF-C expression vector. Using microarrays, we identified a panel of differentially expressed miRNAs in HLECs that had been co-cultured with VEGF-C-transformed gastric cancer cells compared with non-transformed gastric cancer cells. A subset of miRNAs was further validated using qRT-PCR.

RESULTS

We found altered expression of miRNAs in HLECs co-cultured with lymphangiogenesis-inducing VEGF-C-transformed gastric cancer cells, with 47 up-regulated and 42 down-regulated miRNAs. These findings were confirmed by qRT-PCR of selected miRNAs. Furthermore, several miRNAs were differentially expressed in patients with positive lymphatic metastasis of the primary gastric tumor. Up-regulated miRNAs included miR-648, miR-5002-3p, miR-4754, miR-4760-5p, miR-4491, miR-4252, miR-5007-3p, and miR-647; and down-regulated miRNAs included miR-3178, miR-593-5p, miR-4485, miR-135a-3p, miR-17, miR-1469, and miR-124-5p.

CONCLUSIONS

Several lymphangiogenesis-related miRNAs are significantly altered during lymphatic metastasis of gastric cancer.

Residual Stresses and Birefringence in Injection Molding of Semicrystalline Polymer

A composite model for the buildup and the relaxation of residual stresses and birefringence during the injection molding of semicrystalline polymer is proposed. This model takes into account the flow-induced crystallization occurring under nonisothermal conditions. The effects of crystallization on the variations of mechanical and physical properties are considered. The viscoelastic constitutive equation due to Giesekus and Leonov is employed for the calculation of the buildup and relaxation of flow stresses, whereas the Morland-Lee constitutive equation of linear viscoelasticity is utilized for the calculation of the buildup and relaxation of thermal stresses during the molding. The overall residual stresses in the molding are determined based upon the addition of residual flow and thermal stresses. The multilayered micro-structure in the moldings arising due to the flow-induced crystallization is determined. Flow birefringence is related to flow stresses according to the stress-optical rule. An expression is proposed to evaluate the overall residual birefringence based upon the resultant microstructure pattern and residual low birefringence in the moldings. As a result, numerical simulations for idealized injection molding process are formulated to calculate the residual stresses and birefringence in molded semicrystalline polymers. Based upon the above theoretical approach, the numerical simulation schemes are formulated, and a computer program is developed. Based upon the simulations, the effects of molding conditions and molecular weights on the overall residual stresses and birefringence are further evaluated.

Residual Stresses and Birefringence in Injection Molding of Semicrystalline Polymer

The viscoelastic process simulation of the idealized injection molding process for various isotactic polypropylenes having different molecular weights are conducted by using the theoretical formulation developed in the first part of the present study. Molding experiments are performed under a variety of molding conditions, and birefringence measurements are carried out on the molded samples. Based upon the experimental and simulated results of the residual stresses and birefringence, the effects of molding conditions and molecular weights are studied. The influences of flow-induced crystallization kinetics on the buildup and relaxation of residual stresses and birefringence in the moldings are discussed. It has been found that, due to the absence of the flow-induced crystallization in the core region, the flow stresses and birefringence introduced in that region during the filling stage relax shortly after the cavity is filled. Moreover, the low stresses and birefringence get frozen-in due to the occurrence of the low-induced crystallization are relatively large and located within a very narrow region close to the mold wall. The main contribution to the overall residual stresses is found to be due by the residual thermal stresses that are introduced by the progression of crystallization during the postfilling stage. The distribution of the residual birefringence in the moldings is closely related to that of the crystalline microstructure pattern and less dependent upon the level of overall residual stresses.

Anisomycin induces apoptosis of glucocorticoid resistant acute lymphoblastic leukemia CEM-C1 cells via activation of mitogen-activated protein kinases p38 and JNK

Glucocorticoids (GCs) resistance is frequently encountered in children with acute lymphoblastic leukemia (ALL), especially in T-ALL, which usually results in failure of treatment. To find new agent to overcome GC resistance of ALL is an urgent problem. Here we investigated potential effect of anisomycin on GC-resistant T-ALL CEM-C1 cells and explored involved molecular mechanisms. Dramatic growth inhibition and apoptosis in GC resistant CEM-C1 cells and GC-sensitive CEM-C7 cells induced by anisomycin were observed, which presented in a concentration- and time-dependent manner. Correspondingly, anisomycin induced cleaved caspase-3 and up-regulation of pro-apoptotic proteins (BimEL and Bad), meanwhile down-regulation of anti-apoptotic proteins (Mcl-1 and Bcl-2), both in a dose- and time-dependent manner in GC resistant CEM-C1 cells. Anisomycin also induced cell cycle arrest at G0/G1 phase in CEM-C1 cells through increasing expressions of p21 and p27, and attenuating the expression of cyclinA. The rapid up-regulation of phosphorylated mitogen-activated protein kinases (MAPKs) p38 and Jun N-terminal kinase (JNK) were observed after CEM-C1 cells were incubated with anisomycin. The activation of p38 and JNK could be blocked by respective inhibitors (SB203580 for p38 and SP600125 for JNK) accompanied with the inhibition of apoptosis and changes of apoptosis associated proteins in CEM-C1 cells. These results suggested that anisomycin induced apoptosis of CEM-C1 cells via activation of p38 and JNK, and might be an attractive new agent for treatment of GC-resistant ALL.

Comparative Study of Ziegler-Natta and Metallocene Based Polypropylenes in Injection Molding

Injection molding of the isotactic polypropylenes polymerized using metallocene and Ziegler-Natta catalysts and having the same molecular weights was performed. Rheological properties and shear-induced crystallization kinetics were measured and their comparative analysis is made. These data are fitted to the equations necessary for simulation of the injection molding process. Numerous injection molding runs were carried out and pressure measurements during molding were performed. The gapwise distribution of crystallinity, spherulite size and thickness of flow-induced crystallized layer in moldings were measured. The effect of various processing conditions on these values was determined. The measured values were compared with the results obtained from the simulation of injection molding process using unified theory of crystallization proposed earlier. Comparative analysis is made between flow conditions and crystallization behavior of these polymers and their effect on the pressure development and structural characteristics of the moldings.

Systematic evaluation of validated type 2 diabetes and glycaemic trait loci for association with insulin clearance

AIMS/HYPOTHESIS

Insulin clearance is a highly heritable trait, for which few quantitative trait loci have been discovered. We sought to determine whether validated type 2 diabetes and/or glycaemic trait loci are associated with insulin clearance.

METHODS

Hyperinsulinaemic-euglycaemic clamps were performed in two Hispanic-American family cohorts totalling 1329 participants in 329 families. The Metabochip was used to fine-map about 50 previously identified loci for type 2 diabetes, fasting glucose, fasting insulin, 2 h glucose or HbA1c. This resulted in 17,930 variants, which were tested for association with clamp-derived insulin clearance via meta-analysis of the two cohorts.

RESULTS

In the meta-analysis, 38 variants located within seven loci demonstrated association with insulin clearance (p < 0.001). The top signals for each locus were rs10241087 (DGKB/TMEM195 [TMEM195 also known as AGMO]) (p = 4.4 × 10(-5)); chr1:217605433 (LYPLAL1) (p = 3.25 × 10(-4)); rs2380949 (GLIS3) (p = 3.4 × 10(-4)); rs55903902 (FADS1) (p = 5.6 × 10(-4)); rs849334 (JAZF1) (p = 6.4 × 10(-4)); rs35749 (IGF1) (p = 6.7 × 10(-4)); and rs9460557 (CDKAL1) (p = 6.8 × 10(-4)).

CONCLUSIONS/INTERPRETATION

While the majority of validated loci for type 2 diabetes and related traits do not appear to influence insulin clearance in Hispanics, several of these loci do show evidence of association with this trait. It is therefore possible that these loci could have pleiotropic effects on insulin secretion, insulin sensitivity and insulin clearance.

Effects of dietary factors on selenium levels of children to prevent Kashin-Beck disease during a high-prevalence period in an endemic area: a cohort study

Selenium (Se) supplements have been used to control Kashin-Beck disease (KBD) for decades, but the effect of diet without Se supplements is unclear because the prevalence of KBD has decreased. This matched cohort study was undertaken to determine dietary factors affecting selenium nutrition status of children living in KBD areas and the effects of Se supplements in preventing KBD. A total of 593 children aged 5-12 years were randomly selected during the high prevalence period of KBD from 1992 to 1995. Children in one village received Se supplemented (Se+) salt and were matched with three children in 16 other villages who did not receive Se supplemented (Se-) salt. A questionnaire and determinations of occipital hair Se to reflect body Se status were obtained at baseline (April 1992), at 6 months (October 1992), and yearly each April through 1995. Hair Se content in the Se+ group was significantly higher than in the Se- group (P < 0.001) at all time-points and was significantly related to the incidence of suspected KBD symptoms (P = 0.018). Four dietary factors significantly affected hair Se contents. Se levels were increased by consumption of Se+ salt (P < 0.001) and eating meat/egg often (P = 0.019) or occasionally (P = 0.001). Se levels were decreased by consumption of grain mildewed at harvest or in storage (P < 0.001 for each) and drinking ditch, river, or cellar water (P < 0.001; P = 0.002; P < 0.001, respectively). These results show that Se+ salt had a significant effect in maintaining the Se nutrition status of children in this cohort study but that dietary factors in those without Se supplements contributed as well.

Prevalence of cardiovascular disease and risk factors in the Chinese population with impaired glucose regulation: the 2007-2008 China national diabetes and metabolic disorders study

Cardiovascular disease (CVD) is one of the most common chronic diseases in China. This aim of this study is to determine the prevalence of CVDs and risk factors in Chinese impaired glucose regulation subjects.We used a multistage, stratified sampling method to select subjects from the general Chinese population aged 20 years and older. Subjects underwent an oral glucose tolerance test to identify normal glucose tolerance (NGT) and impaired glucose regulation including isolated impaired fasting glucose (i-IFG), impaired glucose tolerance (i-IGT), and combined IFG/IGT and diabetic mellitus (DM). A logistic regression analysis was performed to examine the association between glucose abnormalities and CVD events.We identified that 34 293 subjects had NGT, 1 469 i-IFG, 4 571 i-IGT, 957 IFG/IGT and 4 949 DM. The age-sex standardized prevalence rate of cardiovascular disease was 1.06% (95% CI 0.87-1.28), 1.79% (95% CI 1.37-2.33) and 3.83% (95% CI 2.79-5.24) in NGT, impaired glucose regulation and DM, respectively. Among impaired glucose subjects, prevalence of defined CVD risk factors (smoking, overweight, obesity, hypertension and dyslipidemia) was 29.52% (95% CI: 27.8-31.21), 36.25% (95% CI: 34.29-38.26), 10.05% (95% CI: 8.86-11.37), 36.43% (95% CI: 34.53-38.36) and 69.96% (95% CI: 67.87-71.98), respectively. Compared to 1 risk factor, the odds ratios (ORs) of CVDs with 2, 3 or 4 risk factors were 1.94 (95% CI: 0.74-5.09), 2.76 (95% CI: 1.06-7.21) and 5.84 (95% CI: 1.68-20.26), respectively. Additionally, compared to i-IFGs, ORs of CVDs with i-IGT and IFG/IGT were 2.88 (95%CI 1.36-6.01) and 2.12 (95% CI 0.83-5.44), respectively.The prevalence of cardiovascular risk factors was high in the Chinese impaired glucose regulation population. The postprandial hyperglycemia is more associated with CVD than isolated fasting hyperglycemia.

Neuregulin-1 protects against doxorubicin-induced apoptosis in cardiomyocytes through an Akt-dependent pathway

In previous studies, it has been shown that recombinant human neuregulin-1(rhNRG-1) is capable of improving the survival rate in animal models of doxorubicin (DOX)-induced cardiomyopathy; however, the underlying mechanism of this phenomenon remains unknown. In this study, the role of rhNRG-1 in attenuating doxorubicin-induce apoptosis is confirmed. Neonatal rat ventricular myocytes (NRVMs) were subjected to various treatments, in order to both induce apoptosis and determine the effects of rhNRG-1 on the process. Activation of apoptosis was determined by observing increases in the protein levels of classic apoptosis markers (including cleaved caspase-3, cytochrome c, Bcl-2, BAX and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining). The activation of Akt was detected by means of western blot analysis. The study results showed that doxorubicin increased the number of TUNEL positive cells, as well as the protein levels of cleaved caspase-3 and cytochrome c, and reduced the ratio of Bcl-2/Bax. However, all of these effects were markedly antagonized by pretreament with rhNRG-1. It was then further demonstrated that the effects of rhNRG-1 could be blocked by the phosphoinositole-3-kinase inhibitor LY294002, indicating the involvement of the Akt process in mediating the process. RhNRG-1 is a potent inhibitor of doxorubicin-induced apoptosis, which acts through the PI3K-Akt pathway. RhNRG-1 is a novel therapeutic drug which may be effective in preventing further damage from occurring in DOX-induced damaged myocardium.

Serotonin modulates outward potassium currents in mouse olfactory receptor neurons

Monoaminergic neurotransmitter 5-hydroxytryptamine (5-HT), also known as serotonin, plays important roles in modulating the function of the olfactory system. However, thus far, the knowledge about 5-HT and its receptors in olfactory receptor neurons (ORNs) and their physiological role have not been fully characterized. In the present study, reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the presence of 5-HT(1A) and 5-HT(1B) receptor subtypes in mouse olfactory epithelium at the mRNA level. With subtype selective antibodies and standard immunohistochemical techniques, both receptor subtypes were found to be positively labeled. To further elucidate the molecular mechanisms of 5-HT act on the peripheral olfactory transduction, the whole-cell patch clamp techniques were used on freshly isolated ORNs. We found that 5-HT decreased the magnitude of outward K(+) current in a dose-dependent manner and these inhibitory effects were markedly attenuated by the 5-HT(1A) receptor blocker WAY-100635 and the 5-HT(1B) receptor antagonist GR55562. These data suggested that 5-HT may play a role in the modulation of peripheral olfactory signals by regulating outward potassium currents, both 5-HT(1A) and 5-HT(1B) receptors were involved in this regulation.

Epitope recognition patterns of thyroglobulin antibody in sera from patients with Hashimoto's thyroiditis on different thyroid functional status

Thyroglobulin antibody (TgAb) is a diagnostic serological marker of Hashimoto's thyroiditis (HT). The pathogenesis of HT progression from euthyroidism to hypothyroidism is still not clear. Epitope recognition patterns of TgAb have been shown to be different in individuals who are euthyroid or who have clinical disease. The aim of our study was to investigate the role of thyroglobulin (Tg) epitope specificities in HT progression. Sera from 107 patients with newly diagnosed HT were collected and divided into three groups: patients with hypothyroidism (H, n = 39), subclinical hypothyroidism (sH, n = 31) and euthyroidism (Eu, n = 37). A panel of Tg murine monoclonal antibodies (mAb: PB2, 5E6, 1D4, 5F9, Tg6) and a hircine pAb (N15) were employed as the probe antibodies to define the antigenic determinants recognized by HT sera on competitive enzyme-linked immunosorbent assays (ELISAs). Eight of 39 sera samples in H and seven of 31 in sH inhibited PB2 binding, respectively, whereas none did in Eu. The ratio of sera samples, inhibiting PB2 binding in Eu, was significantly lower than that in H (P = 0.011) and in sH (P = 0.008). For N15, five of 39 sera samples in H, six of 31 in sH and 15 of 37 in Eu inhibited its binding, respectively. The ratio of sera samples, inhibiting N15 binding in Eu, was significantly higher than that in H (P = 0.013). Our study demonstrated that HT patients in different thyroid functional status exhibited different Tg epitope recognition patterns. Epitope patterns of TgAb might be used as a prediction marker of HT progression.