N1-guanyl-1,7-diaminoheptane enhances the chemosensitivity of NSCLC cells to cetuximab through inhibition of eukaryotic translation initiation factor 5A2 activation

OBJECTIVE

N1-guanyl-1, 7-diaminoheptane (GC7), an inhibitor of deoxyhypusine synthase has been shown to exhibit significant anti-cancer activity. However, the biological role of eukaryotic translation initiation factor 5A2 activation (EIF5A2) and GC7 on drug resistance in non-small cell lung cancer (NSCLC) has not been investigated. In this study, we aimed to investigate the therapeutic effect of GC7 combined with cetuximab in NSCLC therapy.

MATERIALS AND METHODS

The current study used cell viability assays, EdU incorporation assays, and western blot to detect that the GC7 exhibited synergistic cytotoxicity with cetuximab in NSCLC.

RESULTS

CCK-8 assays showed that combined treatment with GC7 and cetuximab significantly inhibited the viabilities in three NSCLC cell lines. In addition, EdU incorporation assays also indicated that GC7 co-treatment remarkably enhanced the cetuximab sensitivity in NSCLC cells. Nevertheless, down-regulation of EIF5A2 diminished the regulatory role of GC7 in cetuximab cytotoxicity. Western blot showed that transfection of EIF5A2 siRNA significantly suppressed the protein expression of EIF5A2 in NSCLC cells.

CONCLUSIONS

These findings demonstrate that combined treatment with GC7 could enhance cetuximab sensitivity by inhibiting EIF5A2 in NSCLC cells, implying the potential clinical application of GC7 in cetuximab-based chemotherapy for NSCLC patients.

LINC01225 promotes occurrence and metastasis of hepatocellular carcinoma in an epidermal growth factor receptor-dependent pathway

The long noncoding RNAs (lncRNAs) have long been clarified to participate in hepatocellular carcinoma (HCC) as a biomarker. We carried out the present study in order to identify HCC-related lncRNAs and elucidate the functional roles in the development and progression of HCC. Our previous study has provided that LINC01225 may be an HCC-related gene. Here, we verified that LINC01225 was upregulated in HCC. Knockdown of LINC01225 resulted in inhibited cell proliferation and invasion with activated apoptosis and cell cycle arrest in vitro. Overexpression of LINC01225 in LINC01225 knockdown cells presented that attenuated cell proliferation and invasion were restored and enhanced. Subcutaneous and tail vein/intraperitoneal injection xenotransplantation model in vivo validated reduced tumor progression and metastasis. Investigation of mechanism found that LINC01225 could bind to epidermal growth factor receptor (EGFR) and increase the protein level of EGFR, and subsequently fine tune the EGFR/Ras/Raf-1/MEK/MAPK signaling pathway. Analysis with clinicopathological information suggested a high expression of LINC01225 is positively associated with poor prognosis. We also proved that LINC01225 was stably expressed in serum and can act as a novel biomarker in predicting the diagnosis of HCC. As a conclusion, LINC01225 plays a crucial role in HCC and can act as a biomarker for the diagnosis and prognosis of HCC.

Training of deep microsurgical skill: Establishment of a high-volume intracranial carotid bypass model

OBJECTIVE

To establish a model for a high-volume intracranial carotid bypass operation.

METHODS

High-volume internal carotid-middle cerebral artery bypass was performed on 9 cadaver heads with arteries of porcine forearms as grafts by 6 residents with no previous experience in vascular anastomosis on cadavers. The intima was dissected immediately after the anastomoses were completed to observe the patency of anastomosis.

RESULTS

After different duration periods of training using this model, 36 vascular anastomoses on 18 sides were successfully performed by the 6 residents with a self-made difficulty regulation device. As the difficulty level increased, the time needed for anastomosis lengthened and patency rate showed a decreasing trend. As the amount of training increased, the residents were able to decrease the amount of time to complete the operation with increasing patency rates.

CONCLUSIONS

The model of high-volume internal carotid-middle cerebral artery bypass with arteries of porcine forearms has the advantages of material similarity, easy access of grafts, better simulation of intraoperative conditions, and adjustable difficulties. Our results suggest that this new procedure has a better simulation-training platform which is closer to the real surgical procedure for surgeons willing to master the technique of a high-volume bypass operation.

Deletion of Osr2 Partially Rescues Tooth Development in Runx2 Mutant Mice

Tooth organogenesis depends on genetically programmed sequential and reciprocal inductive interactions between the dental epithelium and neural crest-derived mesenchyme. Previous studies showed that the Msx1 and Runx2 transcription factors are required for activation of odontogenic signals, including Bmp4 and Fgf3, in the early tooth mesenchyme to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 acts downstream of Msx1 to activate Fgf3 expression. Recent studies identified Osr2 as a repressor of tooth development and showed that inactivation of Osr2 rescued molar tooth morphogenesis in the Msx1(-/-) mutant mice as well as in mice with neural crest-specific inactivation of Bmp4. Here we show that Runx2 expression is expanded in the tooth bud mesenchyme in Osr2(-/-) mutant mouse embryos and is partially restored in the tooth mesenchyme in Msx1(-/-)Osr2(-/-) mutants in comparison with Msx1(-/-) and wild-type embryos. Whereas mandibular molar development arrested at the bud stage and maxillary molar development arrested at the bud-to-cap transition in Runx2(-/-) mutant mice, both mandibular and maxillary molar tooth germs progressed to the early bell stage, with rescued expression of Msx1 and Bmp4 in the dental papilla as well as expression of Bmp4, p21, and Shh in the primary enamel knot in the Osr2(-/-)Runx2(-/-) compound mutants. In contrast to the Msx1(-/-)Osr2(-/-) compound mutants, which exhibit nearly normal first molar morphogenesis, the Osr2(-/-)Runx2(-/-) compound mutant embryos failed to activate the expression of Fgf3 and Fgf10 in the dental papilla and exhibited significant deficit in cell proliferation in both the dental epithelium and mesenchyme in comparison with the control embryos. These data indicate that Runx2 synergizes with Msx1 to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 controls continued tooth growth and morphogenesis beyond the cap stage through activation of Fgf3 and Fgf10 expression in the dental papilla.

Involvement of AP-1 in p38MAPK signaling pathway in osteoblast apoptosis induced by high glucose

We investigated the effect of p38MAPK/AP-1 (activator protein-1) signaling on the apoptosis of osteoblasts induced by high glucose. A lentivirus vector of small hairpin RNA (shRNA) targeting p38MAPK was constructed in vitro. Osteoblasts MC3T3-E1 cultured in vitro were treated with vehicle, high glucose, p38MAPK-shRNA transfection, p38MAPK inhibitor, and unrelated shRNA transfection. Apoptosis, protein levels of p38MAPK, and activities of AP-1 in MC3T3-E1 osteoblasts were measured using TUNEL and flow cytometry, Western blot analysis, and an electrophoretic mobility shift assay. Compared with the vehicle group, high glucose induced apoptosis of MC3T3-E1 osteoblasts and activated p38MAPK and AP-1. p38MAPK-shRNA transfection blocked the effect of high glucose stimulation, and the p38MAPK inhibitor showed similar effects as those observed in p38MAPK transfection. Unrelated shRNA had no effect on these changes in MC3T3-E1 osteoblasts induced by high glucose. Therefore, our results suggest that p38MAPK-shRNA reduce apoptosis of MC3T3-E1 osteoblasts induced by high glucose by inhibiting the p38MAPK-AP-1 signaling pathway.

An association analysis between psychophysical characteristics and genome-wide gene expression changes in human adaptation to the extreme climate at the Antarctic Dome Argus

Genome-wide gene expression measurements have enabled comprehensive studies that integrate the changes of gene expression and phenotypic information to uncover their novel associations. Here we reported the association analysis between psychophysical phenotypes and genome-wide gene expression changes in human adaptation to one of the most extreme climates on Earth, the Antarctic Dome Argus. Dome A is the highest ice feature in Antarctica, and may be the coldest, driest and windiest location on earth. It is considered unapproachable due to its hostile environment. In 2007, a Chinese team of 17 male explorers made the expedition to Dome A for scientific investigation. Overall, 133 psychophysical phenotypes were recorded, and genome-wide gene expression profiles from the blood samples of the explorers were measured before their departure and upon their arrival at Dome A. We found that mood disturbances, including tension (anxiety), depression, anger and fatigue, had a strong, positive, linear relationship with the level of a male sex hormone, testosterone, using the Pearson correlation coefficient (PCC) analysis. We also demonstrated that significantly lowest-level Gene Ontology groups in changes of gene expression in blood cells with erythrocyte removal were consistent with the adaptation of the psychophysical characteristics. Interestingly, we discovered a list of genes that were strongly related to significant phenotypes using phenotype and gene expression PCC analysis. Importantly, among the 70 genes that were identified, most were significantly related to mood disturbances, where 42 genes have been reported in the literature mining, suggesting that the other 28 genes were likely novel genes involved in the mood disturbance mechanism. Taken together, our association analysis provides a reliable method to uncover novel genes and mechanisms related to phenotypes, although further studies are needed.

A novel biomarker Linc00974 interacting with KRT19 promotes proliferation and metastasis in hepatocellular carcinoma

Location-associated long noncoding RNA (lncRNA) was reported to interact with target protein via a cis-regulatory process especially for the Flank10kb class lncRNA. Based on this theory, we aimed to explore the regulatory mechanisms of Linc00974 and KRT19 (an lncRNA beyond the Flank10kb class with protein) when we first confirmed the aberrant expression in hepatocellular carcinoma in a previous study. Knockdown of Linc00974 resulted in an inhibition of cell proliferation and invasion with an activation of apoptosis and cell cycle arrest in vitro, which was also validated by a subcutaneous and tail vein/intraperitoneal injection xenotransplantation model in vivo. We further investigated the interaction pattern of Linc00974 and KRT19. MiR-642 was identified, by acting as the competing endogenous RNA in regulating Linc00974 and KRT19. Linc00974 was increased owing to an abnormal hypomethylation promoter, which induced the upregulation of KRT19 via ceRNA interaction, resulting in the activation of the Notch and TGF-β pathways as detected by cDNA microarray. We also discovered Linc00974F-1 stably expressed in the plasma. By the combined analysis of Linc00974F-1 with CYFRA21-1, we found that these joint indicators predicted growth and metastasis of tumor in HCC patients. In conclusion, the combination of Linc00974 and KRT19 may be novel indices for clinical diagnosis of tumor growth and metastasis in HCC, while Linc00974 may become a potential therapeutic target for the prevention of HCC progression.

Correlation of serum adiponectin and adiponectin gene polymorphism with metabolic syndrome in Chinese adolescents

BACKGROUND/OBJECTIVES

To investigate the association of adiponectin and its gene polymorphisms with metabolic syndrome (MetS) and cardiovascular disease (CVD) risk factors in Chinese adolescents.

SUBJECTS/METHODS

This cross-sectional study enrolled 919 healthy middle school students (aged 11-16 years; 46.7% females). All participants underwent anthropometric and biochemical examinations, and MetS was diagnosed using 2007 International Diabetes Federation criteria. The presence of adiponectin and its genotypes of single nucleotide polymorphisms (SNPs) rs266729 (-11377C/G), rs2241766 (+45T/G) and rs1501299 (+276G/T) was detected.

RESULTS

(1) Serum adiponectin levels were negatively correlated with numerous CVD risk factors (all P<0.05), and following adjustments for confounding factors, a lower adiponectin level was an independent risk factor for MetS (odds ratio=5.59; 95% confidence interval: 1.90, 16.41). Central obesity and low levels of high-density lipoprotein cholesterol were positively associated with MetS and reduced serum adiponectin levels. (2) The genotype and frequencies of SNP-11377 and SNP+276 in a MetS group and non-MetS group were not significantly different. Subjects with genotype SNP+45 GG were at higher risk for MetS compared with subjects with genotypes SNP+45 TT (P=0.033) or TT+TG (P=0.021). Subjects with genotype SNP+276 TT or TT+TG had higher levels of serum adiponectin compared with subjects with SNP+276 GG (P=0.012 and 0.014, respectively).

CONCLUSIONS

Adiponectin may be used as a predictive biomarker of MetS, and shows a significant association with CVD risk factors in Chinese adolescents. Adiponectin gene polymorphisms are associated with serum adiponectin concentrations and the presence of MetS.

The Changes of Muscle FGF-6 Expression at Different Time Points after Exercise-induced Muscle Damage

OBJECTIVE

To investigate the changes of fibroblast growth factor (FGF)-6 expression in the regeneration and repair process after exercise-induced muscle damage (EIMD) and the relationship with skeletal muscle regeneration and repair.

METHODS

The expression of FGF-6 at different time points was examined by reverse transcription-polymerase chain reaction (PCR) and immunohistochemistry staining after a downhill treadmill exercise. Skeletal muscle injury and regeneration at different times after EIMD was assessed by haematoxylin and eosin (H and E) staining.

RESULTS

The FGF-6 protein expression was initially elevated and followed by a gradual reduction, while the changes of FGF-6 mRNA were almost all raised after the treadmill exercise.

CONCLUSION

The results point out that FGF-6 is closely related to skeletal muscle regeneration and repair, probably implying a dual function in muscle regeneration.

Anti-Inflammatory Effect of Ebosin on Rat Collagen-Induced Arthritis through Suppressing Production of Interleukin-1β, Interleukin-6 and Tumor Necrosis Factor-α

Reumatoid arthritis (RA) is an autoimmune disease which has been studied experimentally using a wide variety of animal models including collagen-induced arthritis (CIA). Using this CIA model we studied the therapeutic effects and mechanism of action of Ebosin, a novel exopolysaccharide produced by Streptomyces sp. 139, on arthritis. Ebosin at 200, 400 and 600 mg/kg/day was orally administered to rats respectively between day 10 and 30 after immunization with chicken type II collagen. With the treatment arthritic progression was remarkably suppressed. Levels of anti-type II collagen-specific antibody, IL-1β and TNF-α were significantly lower in the Ebosin-treated CIA rats compared with the untreated controls. In cultured fibroblast-like synoviocytes (FLS), remarkable suppression of IL-1β, TNF-α and IL-6 production was detected at both protein and mRNA levels after Ebosin administration. Ebosin also resulted in lower activities of IL-1β-converting enzyme and TNF-α-converting enzyme in FLS. Based on these results, it is concluded that development and progression of rat CIA can be significantly suppressed by orally-administrated Ebosin. The therapeutic effect may be attributed to its inhibition in the production of IL-1β, TNF-α and IL-6 in the CIA rats.