ZD6474, a small molecule tyrosine kinase inhibitor, potentiates the anti-tumor and anti-metastasis effects of radiation for human nasopharyngeal carcinoma

PURPOSE

To investigate the capacity for ZD6474, a small molecule tyrosine kinase inhibitor, to enhance anti-tumor and anti-metastasis effects of radiation on human nasopharyngeal carcinoma (NPC).

EXPERIMENTAL DESIGN

NPC cell lines and xenograft models were evaluated following treatment with ZD6474 and radiation alone and in combination compared with untreated control mice.

RESULTS

Treatment with ZD6474 enhanced the anti-proliferative effect of radiation on NPC cell lines as detected by cell proliferation and apoptosis assays. ZD6474 also induced a significant increase in the radiosensitivity of NPC cells, with radiation enhancement ratios (RERs) ranging from 1.2 to 1.6. Despite the cytotoxicity exhibited by NPC cells following radiotherapy, the invasion and migration of NPC cells was found to be unaffected. In contrast, treatment with ZD6474 strongly inhibited the invasion and migration of NPC cells. When the administration of radiation and ZD6474 was investigated in vitro, the ability of ZD6474 to inhibit activation of the pro-survival signaling pathways induced by radiation was demonstrated. In vivo, ZD6474 significantly enhanced the anti-metastasis effects of radiation, while treatment with radiation and ZD6474 was found to be well tolerated and resulted in a strong inhibition of tumor growth.

CONCLUSIONS

Our results suggest the combination of radiation and ZD6474 represents a promising strategy for the treatment of human NPC.

Alleviating allergic airway diseases by means of short-term administration of IL-2 and dexamethasone

BACKGROUND

IL-2 combined with dexamethasone can upregulate regulatory T (Treg) cells, but the mechanism is still under exploration.

OBJECTIVE

Although previous studies focused on upregulating Treg cells in normal mice, here we investigated whether the IL-2 and dexamethasone combination treatment can upregulate Treg cells in pathological conditions, specifically in alleviating allergic airway disease. We also examined the potential pathway involved in Treg cell upregulation by IL-2 and dexamethasone.

METHODS

We evaluated the dose of IL-2 and dexamethasone required to upregulate Treg cells in vivo and in vitro. We also tested IL-2 and dexamethasone in the intervention of allergic airway disease in a murine model.

RESULTS

We found that administration of 400,000 IU of IL-2 and 0.1 mg of dexamethasone per mouse was effective in upregulating Treg cells, as well as in alleviating allergic airway disease in an established animal model, but this phenomenon disappeared after anti-CD25 antibody administration. We discovered that an in vitro low dose of IL-2 can protect Treg cells did not protect CD4(+)CD25(-) cells from dexamethasone-induced apoptosis by affecting forkhead box O3a phosphorylation through the Akt and serum and glucocorticoid-induced protein kinase pathways.

CONCLUSIONS

IL-2/dexamethasone treatment can alleviate existing allergic airway diseases by upregulating Treg cells in vivo. A low dose of IL-2 (10(-9) to 10(-11) mol/L) can protect Treg cells but not CD4(+)CD25(-) cells from dexamethasone-induced apoptosis in vitro, thereby explaining a possible mechanism of increased proportion of Treg cells.

Single-primer PCR correction: a strategy for false-positive exclusion

Polymerase chain reaction (PCR) technology plays an important role in molecular biology research, but false-positive and nonspecific PCR amplification have plagued many researchers. Currently, research on the optimization of the PCR system focuses on double-primer-based PCR products. This research has shown that PCR amplification based on single-primer binding to the DNA template is an important contributing factor to obtaining false-positive results, fragment impurity, and nonspecific fragment amplification, when the PCR conditions are highly restricted during PCR-based target gene cloning, detection of transgenic plants, simple-sequence repeat marker-assisted selection, and mRNA differential display. Here, we compared single- and double-primer amplification and proposed "single-primer PCR correction"; improvements in PCR that eliminate interference caused by single-primer-based nonspecific PCR amplification were demonstrated and the precision and success rates of experiments were increased. Although for some kinds of experiments, the improvement effect of single-primer PCR correction was variable, the precision and success rate could be elevated at 12-50% in our experiment by this way.

Liraglutide provides similar glycaemic control as glimepiride (both in combination with metformin) and reduces body weight and systolic blood pressure in Asian population with type 2 diabetes from China, South Korea and India: a 16-week, randomized, double-blind, active control trial(*)

AIM

To assess and compare the efficacy and safety of liraglutide with those of glimepiride, both in combination with metformin for the treatment of type 2 diabetes in Asian population from China, South Korea and India.

METHODS

A 16-week, randomized, double-blind, double-dummy, four-arm, active control trial was carried out. In total, 929 subjects with type 2 diabetes with a mean (±s.d.) age of 53.3 ± 9.5 years, HbA₁(c) of 8.6 ± 1.0% and body weight of 68.1 ± 11.7 kg were randomized (liraglutide 0.6, 1.2 or 1.8 mg once daily or glimepiride 4 mg once daily all in combination with metformin: 1 : 1 : 1 : 1). One subject withdrew immediately after randomization and before exposure.

RESULTS

HbA₁(c) was significantly reduced in all groups compared with baseline. Treatment with liraglutide 1.2 and 1.8 mg was non-inferior to glimepiride (mean HbA₁(c) reduction: 1.36% points, 1.45% points and 1.39% points, respectively). No significant difference was shown in the percentage of subjects reaching American Diabetes Association HbA₁(c) target <7% or American Association of Clinical Endocrinologists target ≤6.5% between liraglutide 1.2 and 1.8 mg and glimepiride. Liraglutide was associated with a 1.8-2.4 kg mean weight reduction, compared with a 0.1 kg mean weight gain with glimepiride. Liraglutide led to a significantly greater reduction in systolic blood pressure (SBP) compared with glimepiride. Two subjects in the glimepiride group reported major hypoglycaemia while none in the liraglutide groups. Liraglutide was associated with about 10-fold lower incidence of minor hypoglycaemia than glimepiride. Gastrointestinal disorders were the most common adverse events (AEs) for liraglutide, but were transient and resulted in few withdrawals.

CONCLUSIONS

In Asian subjects with type 2 diabetes, once-daily liraglutide led to improvement in glycaemic control similar to that with glimepiride but with less frequent major and minor hypoglycaemia. Liraglutide also induced a significant weight loss and reduced SBP and was generally well tolerated. The most frequently reported AE was transient nausea. The effect of liraglutide in this Asian population is comparable to the effects seen in Caucasian, African American and Hispanic populations in global liraglutide phase 3 trials.

Problems with and a system to eliminate single-primer PCR product contamination in simple sequence repeat molecular marker-assisted selection in soybean

Polymerase chain reaction (PCR) provides a foundation for simple sequence repeat molecular marker-assisted selection (SSR MAS) in soybean. This PCR system and its various conditions have been optimized by many researchers. However, current research on the optimization of the PCR system focuses on double-primer PCR products. We compared single- and double-SSR primer PCR products from 50 soybean samples and found that the use of single-PCR primers in the reaction system can lead to amplified fragments of portions of the SSR primers in the PCR process, resulting in both false-positives and fragment impurity of double-primer PCR amplification, inconvenient for subsequent analysis. We used "single-primer PCR correction" to eliminate interference caused by single-primer nonspecific PCR amplification and improve PCR quality. Using this method, the precision and success rates of SSR MAS in soybean can be increased.

Plant height affects Fusarium crown rot severity in wheat

Effects of plant height on Fusarium crown rot (FCR) disease severity were investigated using 12 pairs of near-isogenic lines (NILs) for six different reduced height (Rht) genes in wheat. The dwarf isolines all gave better FCR resistance when compared with their respective tall counterparts, although the Rht genes involved in these NILs are located on several different chromosomes. Treating plants with exogenous gibberellin increased FCR severity as well as seedling lengths in all of the isolines tested. Analysis of the expression of several defense genes with known correlation with resistance to FCR pathogens between the Rht isolines following FCR inoculation indicated that the better resistance of the dwarf isolines was not due to enhanced defense gene induction. These results suggested that the difference in FCR severity between the tall and dwarf isolines is likely due to their height difference per se or to some physiological and structural consequences of reduced height. Thus, caution should be taken when considering to exploit any FCR locus located near a height gene.

Obesity, insulin resistance and the prevalence of atopy and asthma in US adults

BACKGROUND

The roles of obesity and insulin resistance in asthma and atopy are not well understood. We investigated whether there is an association of obesity and insulin resistance with asthma and atopy prevalence in US adults.

METHODS

Data from the 2005-2006 National Health and Nutrition Examination Survey were analyzed by multivariate logistic regression, controlling for sex, age, ethnicity, income, and smoking status. Obesity was measured by body mass index (BMI) and waist circumference, and insulin resistance by the homeostasis model assessment. Asthma was defined by self-report of ever receiving a diagnosis and still having asthma currently, and atopy by any positive specific serum IgE responses to a panel of aeroallergens.

RESULTS

Neither obesity measure nor insulin resistance was associated with atopy. Obesity was positively associated with asthma overall (odds ratio [OR] for obese vs normal BMI = 2.28, 95% CI: 1.76, 2.96; OR for obese vs normal waist circumference = 1.75; 95% CI: 1.22, 2.51) but insulin resistance was not (OR = 1.26; 95% CI: 0.80, 1.98). Obesity was also associated with nonatopic asthma (OR for obese vs normal BMI = 2.5; 95% CI: 1.2, 5.2; OR for obese vs normal waist circumference = 2.07, 95% CI: 1.21, 3.54), while obese BMI was also associated with atopic asthma (OR = 2.04, 95% CI: 1.37, 3.03). Obesity remained independently associated with all asthma outcomes after controlling for insulin resistance.

CONCLUSION

Obesity was independently associated with asthma, and atopic and nonatopic asthma, after controlling for insulin resistance and socio-demographic factors. There was no evidence that insulin resistance was associated with atopy or asthma.

Identification of targets of specific miRNAs by selective amplification of Ago2-associated mRNA

To study the function of a miRNA, it is necessary to identify its target genes. The most common methods to reveal miRNA target genes rely on ectopically expressed tagged Ago2 and nonphysiological overexpression or inhibition of the miRNA of interest. To uncover the natural association between miRNAs and their target genes, we isolated endogenous Ago2 protein followed by a selective strategy, which only amplified target genes of the selected miRNA from the purified RNA-induced silencing complex by miRNA specific primers. This enabled us to identify the mRNAs regulated by miRNAs of interest. Our data demonstrated that this strategy is effective and highly credible. Moreover, our results showed the evidence of efficient miRNA target sites in 5' untranslated regions and open reading frames of target mRNAs.

Seasonal changes in antifreeze protein gene transcription and water content of beetle Microdera punctipennis (Coleoptera, Tenebrionidae) from Gurbantonggut desert in Central Asia

Desert beetle Microdera punctipennis (Coleoptera: Tenebriondae) is a special species in Gurbantonggut Desert in Central Asia. To investigate the possible strategy it employs for cold survival, seasonal changes in supercooling point (SCP), body water content, haemolymph osmolality and antifreeze protein gene (Mpafp) expression were measured over 13 months. Our results show SCPs in M. punctipennis adults changed from -8.0°C in summer to -18.7°C in winter. During winter, adults endured modest water loss; total water decreased from 65.4 percent in summer to 55.9% in winter. Mpafp mRNAs level increased by 13.1 fold from summer to early winter, and haemolymph osmolality increased accordingly from 550 mOsm to 1486 mOsm. Correlation coefficient of Mpafp mRNAs level and SCP indicates that Mpafp mRNA explained 65.3 percent of the variation in SCPs. The correlation between Mpafp mRNA level and total water reflected an indirect influence of antifreeze protein on water content via reducing SCP.

Production of Macrophomina phaseolina Conidia by Multiple Soybean Isolates in Culture

Macrophomina phaseolina is the cause of charcoal rot of soybean (Glycine max). Resistance to M. phaseolina in commercial soybean cultivars is not common but is needed in locations where the disease is chronic and severe. The objective of this study was to develop a reliable method to produce sufficient M. phaseolina conidia that can be used to inoculate soybean plants in a high-throughput resistance-screening program. Production of pycnidia is not common on most culture media, such as potato dextrose agar, but can be produced on media containing plant parts or oilseed extracts. Seven semi-defined media were tested to induce pycnidia production. Results indicated that the number of pycnidia that were produced by eight M. phaseolina isolates was dependent on induction medium; however, peanut butter extract-saturated filter paper placed over soynut butter extract agar (PESEA) allowed for greater pycnidia and conidia production than the other media tested. Production of pycnidia on PESEA ranged from 269 to 1,082 per plate. There were no differences among isolates in germination of conidia produced on PESEA, which averaged 83 ± 2% germination. A conidial suspension from one M. phaseolina isolate produced on PESEA and inoculated onto soybean radicles significantly distinguished (P < 0.01) 'DT97-4290', a soybean genotype with partial resistance to charcoal rot, from a susceptible genotype, 'LS98-0358'. Results of this study indicated that multiple isolates of M. phaseolina from soybean produced sufficient amounts of conidia on PESEA to use as inoculum. This conidia inoculum production method will facilitate soybean charcoal rot resistance screening evaluation with different soybean isolates.