Plastic footprint deteriorates dryland carbon footprint across soil-plant-atmosphere continuum.

Plastic fragments are widely found in the soil profile of terrestrial ecosystems, forming plastic footprint and posing increasing threat to soil functionality and carbon (C) footprint. It is unclear how plastic footprint affects C cycling, and in particularly permanent C sequestration. Integrated field observations (including 13C labelling) were made using polyethylene and polylactic acid plastic fragments (low-, medium- and high-concentrations as intensifying footprint) landfilling in soil, to track C flow along soil-plant-atmosphere continuum (SPAC). The result indicated that increased plastic fragments substantially reduced photosynthetic C assimilation (p < 0.05), regardless of fragment degradability. Besides reducing C sink strength, relative intensity of C emission increased significantly, displaying elevated C source. Moreover, root C fixation declined significantly from 21.95 to 19.2 mg m-2, and simultaneously root length density, root weight density, specific root length and root diameter and surface area were clearly reduced. Similar trends were observed in the two types of plastic fragments (p > 0.05). Particularly, soil aggregate stability was significantly lowered as affected by plastic fragments, which accelerated the decomposition rate of newly sequestered C (p < 0.05). More importantly, net C rhizodeposition declined averagely from 39.77 to 29.41 mg m-2, which directly led to significant decline of permanent C sequestration in soil. Therefore, increasing plastic footprint considerably worsened C footprint regardless of polythene and biodegradable fragments. The findings unveiled the serious effects of plastic residues on permanent C sequestration across SPAC, implying that current C assessment methods clearly overlook plastic footprint and their global impact effects.

[Effect of elongated-needle by Hui-puncture method on piriformis syndrome].

OBJECTIVE: To observe the clinical effect of elongated needle by Hui-puncture method in the treatment of piriformis syndrome. METHODS: A total of 100 piriformis syndrome patients were randomly divided into routine acupuncture group (n＝50) and elongated needle by Hui-puncture method (Hui-puncture) group (n＝50). For patients of the routine acupuncture group, Huantiao (GB30), Juliao (GB29), Zhibian (BL54), Weizhong (BL40), Yanglingquan (GB34), Juegu (GB39) and Ashi-point on the affected side of the body were punctured with filiform needles for 30 min. And for those of the Hui-puncture group, elongated needles were respectively inserted into GB30 and Ashi-point. The treatment was conducted once every other day for 10 times. The visual analog scale (VAS) pain score and the severity scores of symptoms (hip pain, lower limb pain, walking ability, straight leg elevation test, piriformis muscle tension test, piriformis muscle tenderness, 0-15 points) were measured before and after the treatment. The therapeutic effect was assessed by Criteria for Diagnosis and Assessment of Therapeutic Effect of Syndromes or Illnesses of Traditional Chinese Medicine (1994). RESULTS: After the treatment, the scores of symptoms and VAS scores of both routine acupuncture and Hui-puncture groups were significantly decreased in comparison with their own pre-treatment (P<0.05), and the scores of the two indexes of the Hui-puncture group were evidently lower than those of the routine acupuncture group (P<0.05). Of the two 50 cases in the routine acupuncture and Hui-puncture groups, 39 and 47 were effective, with the effective rate being 78.00% and 94.00%, respectively. The comprehensive therapeutic effect of the Hui-puncture group was significantly superior to that of the routine acupuncture group (P<0.05). CONCLUSION: Elongated-needle by Hui-puncture method has significant effect in treating piriformis syndrome patients and is worthy of promotion.

Long noncoding RNA PTPRG-AS1 acts as a microRNA-194-3p sponge to regulate radiosensitivity and metastasis of nasopharyngeal carcinoma cells via PRC1.

Protein regulator of cytokinesis 1 (PRC1) has been reported in correlation with various malignancies. Functionality of PRC1 in nasopharyngeal carcinoma (NPC) was investigated, in perspective of long noncoding RNA (lncRNA) regulatory circuitry. Aberrant expressed messenger RNA and lncRNA were screened out from the Gene Expression Omnibus microarray database. NPC cell line CNE-2 was adopted for in vitro study and transfected with mimic or short hairpin RNA of miR-194-3p and PTPRG-AS1. The radioactive sensitivity, cell viability, migration, invasion, and apoptosis were detected. PTPRG-AS1 and PRC1 were upregulated in NPC, whereas miR-194-3p was downregulated. PTPRG-AS1 was found to specifically bind to miR-194-3p as a competing endogenous RNA and miR-194-3p targets and negatively regulates PRC1. Overexpressed miR-194-3p or silenced PTPRG-AS1 resulted in enhanced sensitivity to radiotherapy and cell apoptosis along with suppressed cell migration, invasion and proliferation in NPC. Furthermore, impaired tumor formation was also caused by miR-194-3p overexpression or PTPRG-AS1 suppression through xenograft tumor in nude mice. In our study, PTPRG-AS1/miR-194-3p/PRC1 regulatory circuitry was revealed in NPC, the mechanism of which can be of clinical significance for treatment of NPC.

[Influence of Calcium Ion Pre-treatment on Phosphate Adsorption onto Magnetic Zirconium/Iron-modified Bentonite].

Two kinds of magnetic zirconium/iron-modified bentonites (ZrFeBTs), including magnetic zirconium/iron modified raw bentonite (ZrFeRBT) and magnetic zirconium/iron-modified Ca2+-pretreated bentonite, (ZrFeCaBT) were prepared and characterized. Their phosphate adsorption characteristics were compared to determine the effect of the Ca2+ pre-treatment on the adsorption of phosphate onto ZrFeBTs. The results showed that the as-prepared ZrFeBTs contained Fe3O4 and Zr, and the content of exchangeable Ca2+ in ZrFeCaBT was much higher than that in ZrFeRBT. The adsorption isotherm data exhibited good agreement with the Langmuir isotherm model, with maximum monolayer phosphate adsorption capacities of 8.70 mg·g-1 and 11.5 mg·g-1 for ZrFeRBT and ZrFeCaBT, respectively. The isotherm and kinetics studies showed that the adsorption of phosphate on ZrFeBTs was a chemisorption process. The phosphate adsorption capacities for ZrFeBTs decreased with increasing solution pH. The ZrFeBTs exhibited a high selective adsorption for phosphate in the presence of anions and cations, including Cl-, HCO3-, SO42-, NO3-, Na+, K+, Mg2+, and Ca2+. Furthermore, coexisting Ca2+ greatly enhanced the adsorption of phosphate onto ZrFeBTs. The pre-treatment of raw bentonite with Ca2+ significantly improved the adsorption of phosphate onto ZrFeBTs.

Analysis of Differential Expressions of Long Non-coding RNAs in Nasopharyngeal Carcinoma Using Next-generation Deep Sequencing.

Background: Little knowledge about long non-coding RNAs(lncRNAs) in nasopharyngeal carcinoma (NPC) has been acquired. Methods: Next-generation sequencing was applied in 7 cases of NPC tissues and 7 cases of normal tissues in nasopharynx. PLEX, CNCI and CPAT soft-wares were used to predict novel lncRNAs. Real-time Quantitative PCR (qPCR) further validated the data in 20 cases of NPC tissues and 14 cases of normal tissues. Then the cis-regulators and trans-regulators and potential biological functions together with pathways were predicted by Bioinformatics. Results: Totally, 4248 novel lncRNAs were found to be expressed in our samples. And 2192 lncRNAs and 23342 mRNAs were considered to be differentially expressed in NPC. Among the results, 306 lncRNAs and 4599 mRNAs were significantly up-regulated, whereas 204 lncRNAs and 2059 mRNAs were significantly down-regulated, respectively. Moreover, 62 lncRNAs trans-regulated genes were involved in Epstein-Barr virus (EBV) infection pathway in our study. Jun proto-oncogene (JUN), which was related to a cis-regulator lncRNA RP4-794H19.1, was enriched in cancers and involved in Tumor Necrosis Factor (TNF) signaling pathway, might play a key role in NPC. Conclusion: These findings broadened the lncRNAs landscape of NPC tissues and shed light on the roles of these lncRNAs, which might be conducive to the comprehensive management of NPC.

The autonomous cell fate specification of basal cell lineage: the initial round of cell fate specification occurs at the two-celled proembryo stage.

In angiosperms, the first zygotic division usually gives rise to two daughter cells with distinct morphologies and developmental fates, which is critical for embryo pattern formation; however, it is still unclear when and how these distinct cell fates are specified, and whether the cell specification is related to cytoplasmic localization or polarity. Here, we demonstrated that when isolated from both maternal tissues and the apical cell, a single basal cell could only develop into a typical suspensor, but never into an embryo in vitro. Morphological, cytological and gene expression analyses confirmed that the resulting suspensor in vitro is highly similar to its undisturbed in vivo counterpart. We also demonstrated that the isolated apical cell could develop into a small globular embryo, both in vivo and in vitro, after artificial dysfunction of the basal cell; however, these growing apical cell lineages could never generate a new suspensor. These findings suggest that the initial round of cell fate specification occurs at the two-celled proembryo stage, and that the basal cell lineage is autonomously specified towards the suspensor, implying a polar distribution of cytoplasmic contents in the zygote. The cell fate transition of the basal cell lineage to the embryo in vivo is actually a conditional cell specification process, depending on the developmental signals from both the apical cell lineage and maternal tissues connected to the basal cell lineage.

Clinical significance of integrin-linked kinase in laryngeal squamous cell carcinoma.

OBJECTIVE: To investigate the expression of integrin-linked kinase (ILK) and its relationship with clinicopathological parameters in laryngeal squamous cell carcinoma (LSCC). METHODS: 116 patients who had previously undergone complete resection of tumor for LSCC were studied retrospectively. The level of ILK expression in tumor tissues and adjacent nontumor tissues were determined by immunohistochemistry. RESULTS: Increased expression of ILK was found in 65.5% of cases. The expression of ILK protein was significantly associated with tumor grade (p=0.046), lymph node metastasis (p=0.020), and pTNM stage (p=0.019). Kaplan-Meier survival estimates showed a significant correlation between ILK expression and patient survival rate (log-rank p<0.05). The multivariate survival analysis revealed that N status was statistically significant prognostic factor (p<0.001). Other parameters, such as ILK expression, cannot predict disease prognosis separately. CONCLUSION: Increased expression of integrin-linked kinase is associated with lymph node metastases and patient survival rate in laryngeal squamous cell carcinoma. However, it does not appear to be an independent prognostic predictor in LSCC.

Inhibiting ROS-NF-κB-dependent autophagy enhanced brazilin-induced apoptosis in head and neck squamous cell carcinoma.

Autophagy modulation has been considered a potential therapeutic strategy for head and neck squamous cell carcinoma (HNSCC). A previous study confirmed that brazilin might possess significant anti-carcinogenic activity. However, whether brazilin induces autophagy and its roles in cell death in HNSCC are still unclear. In this study, we have shown that brazilin induced significant apoptosis in the Cal27 HNSCC cell line but not in oral keratinocyte cell line (OKC). In addition to showing apoptosis induction, we demonstrated the brazilin-induced autophagic response in the Cal27 cells, as evidenced by the formation of GFP-LC3 puncta, and also showed the upregulation of LC3-II and Beclin-1. Moreover, pharmacologically or genetically blocking autophagy enhanced the brazilin-induced apoptosis, indicating the cytoprotective role of autophagy in brazilin-treated Cal27 cells. Moreover, brazilin activated nuclear factor kappa B (NF-κB p65) nuclear translocation and increased NF-κB p65 reporter activity, which contributed to the upregulation of autophagy-related genes, including LC3-II and Beclin-1. Importantly, we found that brazilin triggered reactive oxygen species (ROS) generation in Cal27 cells. Furthermore, N-acetyl-cysteine (NAC), a ROS scavenger, abrogated the effects of brazilin on the NF-κB p65-dependent autophagy. Taken together, our results demonstrated that brazilin increased the NF-κB p65-dependent autophagy through the promotion of ROS signalling pathways in HNSCC. These data also suggest that a strategy of blocking ROS-NF-κB p65-dependent autophagy to enhance the activity of brazilin warrants further attention for the treatment of HNSCC.

Embelin prevents LMP1-induced TRAIL resistance via inhibition of XIAP in nasopharyngeal carcinoma cells.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in the majority of tumor cells, whilst sparing normal cells. However, the potential use of TRAIL in the treatment of cancer is limited by the inevitable emergence of drug resistance. The present study reports the upregulation of latent membrane protein 1 (LMP1)-induced TRAIL resistance via the enhanced expression of X-linked inhibitor of apoptosis protein (XIAP) in nasopharyngeal carcinoma (NPC) cells. LMP1-positive NPC cells were indicated to be more sensitive to TRAIL compared with LMP1-negative NPC cells in three NPC cell lines. CNE-1 is a LMP1-negative NPC cell line that was transfected with pGL6-LMP1; following which, sensitivity to TRAIL decreased. LMP1-induced TRAIL resistance was associated with the decreased cleavage of caspase-8,-3 and -9, BH3 interacting domain death agonist (Bid) and mitochondrial depolarization, without any effects on the expression of the death receptors, B-cell lymphoma (Bcl)-2 and Bcl-extra long. Knockdown of XIAP with small interfering RNA increased caspase-3 and -9 and Bid cleavage, and prevented LMP1-induced TRAIL resistance. Furthermore, embelin, the inhibitor of XIAP, prevented LMP1-induced TRAIL resistance in the Epstein-Barr virus (EBV)-positive CNE-1-LMP1 and C666-1 NPC cell lines. However, embelin did not enhance TRAIL-induced apoptosis in NP-69, which was used as a benign nasopharyngeal epithelial cell line. These data show that LMP1 inhibits TRAIL-mediated apoptosis by upregulation of XIAP. Embelin may be used in an efficacious and safe manner to prevent LMP1-induced TRAIL resistance. The present study may have implications for the development and validation of novel strategies to prevent TRAIL resistance in EBV-positive NPC.

Association of RUNX3 Methylation with Clinical Outcome and Cell Migration/Invasion in Laryngeal Squamous Cell Carcinoma.

This study identifies promoter methylation status of RUNX3 in 77 LSCC patient tissues and their paired adjacent healthy tissues. Hypermethylation percentage RUNX3 occurred in LSCC samples was significantly higher than that in normal tissues, as well as associated with suppression of RUNX3 expression, TNM classification of malignant tumors stage, lymph node metastasis and poor overall survival rate. Reduced methylation and increased expression of RUNX3 genes in vitro was observed and decreased cell migration was further confirmed following 5-azacytidine treatment. RUNX 3 promoter hypermethylation can lead to down-regulation of RUNX3 in LSCC cancerous tissue.

Pharyngoesophageal perforation 3 years after anterior cervical spine surgery: a rare case report and literature review.

Pharyngoesophageal perforation after anterior cervical spine surgery is rare and the delayed cases were more rarely reported but potentially life-threatening. We report a case of pharyngoesophageal perforation 3 years after anterior cervical spine surgery. The patient presented with dysphagia, fever, left cervical mass and developing dyspnea 3 years after cervical spine surgery for trauma. After careful examinations, he underwent an emergency tracheostomy, neck exploration, hardware removal, abscess drainage and infected tissue debridement. 14 days after surgery, CT of the neck with oral contrast demonstrated no contrast extravasation from the esophagus. Upon review of literature, only 14 cases of pharyngoesophageal perforation more than 1 year after anterior cervical spine surgery were found. We discussed possible etiology, diagnosis and management and concluded that in cases of dysphagia, dyspnea, cervical pain, swelling and edema of the cervical area even long time after anterior cervical spine surgery, potential pharyngoesophageal damage should be considered.

Clinical significance of TrkB expression in nasopharyngeal carcinoma.

Recent research has demonstrated that tropomyosin­related kinase B (TrkB) plays an important role in neuronal survival, differentiation and migration; yet, its specific role in human nasopharyngeal carcinoma (NPC) is unclear. To elucidate its role in NPC, we examined TrkB expression in NPC tissues and cell lines, and investigated the correlation between TrkB expression and prognosis in patients with NPC. Immunohistochemical analysis was performed on NPC specimens from 108 patients with follow-up information. Additionally, reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analyses were used to determine TrkB expression levels in NPC and noncancerous nasopharyngeal tissues. RT-PCR and western blot analyses were also used to determine TrkB expression levels in 7 NPC cell lines and a nasopharyngeal epithelium cell line. High TrkB expression was significantly correlated with T classification, lymph node metastasis and clinical stage, respectively. Patients with NPC who had high TrkB expression had reduced disease-free survival and overall survival when compared with patients who had low TrkB expression. Multivariate Cox regression analysis revealed that TrkB overexpression was an independent prognostic factor for patients with NPC. Furthermore, TrkB was overexpressed in NPC specimens and cell lines. TrkB expression levels were significantly increased in NPC specimens, and enhanced levels were correlated with a poor prognosis in patients with NPC. These findings suggest that TrkB may contribute to NPC progression and represent a novel prognostic indicator for patients with NPC.

Prognostic significance of Beclin-1 expression in laryngeal squamous cell carcinoma.

Beclin-1 plays a critical role in the regulation of autophagy, apoptosis, differentiation and the development and progression of cancer. The aim of the present investigation was to analyze the Beclin-1 protein expression and to assess its prognostic significance in tissue of laryngeal squamous cell carcinoma (LSCC). Beclin-1 protein expression in 82 primary laryngeal squamous cell carcinoma and 40 paracarcinoma non-tumor tissue samples was analyzed by immunohistochemistry and correlated with clinicopathological parameters and patients' outcome. The expression of Beclin-1 in tumor tissues was significantly lower than that in non-tumor tissues (P = 0.035). Reduced Beclin-1 expression was significantly correlated with lymph node metastases (P = 0.021). Kaplan-Meier survival estimates showed a significant correlation between Beclin-1 expression and patient's survival rate (log-rank P < 0.05). Multivariate Cox proportional hazards model analysis confirmed that lymph node metastases (P = 0.048) and Beclin-1 expression (P = 0.029) were statistically significant, independent prognostic factors for LSCC. Our findings suggested that decreased Beclin-1 expression and lymph node metastases, as examined by immunohistochemistry, are both independent biomarker for poor prognosis of patients with LSCC.

Value of fused positron emission tomography CT in detecting primaries in patients with primary unknown cervical lymph node metastasis.

OBJECTIVE: Identification of the primary tumour can prolong the life expectancy of patients with primary unknown cervical lymph node metastasis (PUCLNM) through targeted therapy. This study investigated the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET-CT) at identifying primaries in patients with PUCLNM. METHODS: Twenty-seven patients (21 males and 6 females, median age 48.2 ± 16.3, age range 30-73) with PUCLNM underwent FDG PET-CT to search for the primary tumour, which could not be detected by conventional diagnostic modalities. The results were analysed and correlated with either pathological findings or clinical follow up. RESULTS: Pathological FDG uptake suspicious for the primary was detected in 13 cases, while the primary tumour remained occult in 14 cases. Eleven of 13 patients with suspected primaries were confirmed by histological findings. One with a coexisting second tumour and three with unexpected distant metastases were found in patients with confirmed primaries. The most common primary location in patients with PUCLNM found in our study was nasopharynx. In those 14 patients with negative FDG PET-CT results, only one patient had a primary malignancy that was proven histologically after endoscopy with biopsy during a period of clinical follow up. The sensitivity, specificity, accuracy and positive predictive values of FDG PET-CT were 91.7, 86.7, 88.9 and 84.6%, respectively. CONCLUSION: FDG PET-CT is a useful tool to help search for unknown primaries in patients with cervical lymph node metastasis and has an acceptable diagnostic yield for the detection of distant malignancies.

Simultaneously targeting bcl-2 and Akt pathways sensitizes nasopharyngeal carcinoma to tumor necrosis factor-related apoptosis-inducing ligand.

The 5-year survival rate of nasopharyngeal carcinoma (NPC) is disappointing despite the much improved technologies in its treatment. Thus, finding more effective treatment for NPC has become an urgent priority. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in most tumor cells while sparing normal cells. However, its potential in the treatment of NPC has been limited by the eventual emergence of drug resistance. Bcl-2 and Akt contribute to TRAIL resistance in some cancer cells. In this study, CNE-2 was found to be the most resistant NPC cell line to TRAIL, and whether Bcl-2 small-interfering RNA (siRNA) and phosphatidylinositol 3-kinase (PI3-K) inhibitors (LY294002 and Wortmannin) could prevent TRAIL resistance in CNE-2 was also investigated. Results showed that both Bcl-2 siRNA and PI3-K inhibitors could prevent TRAIL resistance in CNE-2. Bcl-2 siRNA sensitized CNE-2 by activating the intrinsic apoptotic pathway and PI3-K inhibitors sensitized CNE-2 by activating both intrinsic and extrinsic pathways. Further, simultaneously targeting Bcl-2 and Akt was found to be a more efficient approach to prevent TRAIL resistance in CNE-2 and this synergistic effect happened at the level of Bid downstream. At last, the combinative treatments did not enhance toxicity of TRAIL in MRC5, a human benign fibroblast cell line. This study suggests that simultaneously targeting Bcl-2 and Akt pathway might be effective in preventing TRAIL resistance of NPC cells.

Reduced E-cadherin expression is associated with lymph node metastases in laryngeal squamous cell carcinoma.

OBJECTIVE: To investigate the expression of E-cadherin and its relationship with clinicopathological parameters in laryngeal squamous cell carcinoma (LSCC). METHODS: Sixty-four patients who had previously undergone complete resection of tumor for LSCC were studied retrospectively. The level of E-cadherin expression in tumor tissues and paired nontumor tissues were determined by immunohistochemistry. RESULTS: The expression of E-cadherin in tumor tissues was significantly lower than nontumor tissues (P<0.001). Reduced E-cadherin expression was significantly correlated with lymph node metastases (P<0.001). Kaplan-Meier survival estimates showed a significant correlation between E-cadherin expression and patient survival rate (log-rank P<0.05). Multivariate Cox proportional hazards model analysis confirmed that lymph node metastases (P=0.001) and tumor stage (P=0.013) were statistically significant, independent predictor of prognosis. CONCLUSION: Expression of E-cadherin is an independent predictor of lymph node metastases in LSCC. However, it does not appear to be a better prognostic predictor than other established markers in LSCC.

[Correlation study on effects of electroacupuncture on the muscle condition and MNCV in rabbits with lumbar nerve root compression].

OBJECTIVE: To observe the effects of electroacupuncture on the muscle condition and electrophysiology of the muscle in rabbits with lumbar nerve root compression and to explore potential mechanisms. METHODS: Twenty-four New Zealand white rabbits were randomly divided into a normal group, a model group, a medication group and an electroacupuncture group. The rabbit model with lumbar nerve root compression was established in the model group, the medication group and the electroacupuncture group. The model and the treatment were not produced in the normal group. The medication group was treated with oral administration of Loxoprofen tablets at a dose of 30 mg each day for 14 days. The electroacupuncture group was treated with electroacupuncture at "Jiaji" (EX-B 2) of L5 and L6 for 14 days. The hibateral muscle condition before and after making model and after treatment was detected and the electromyogram and the nerve conduction velocity (NCV) were observed. RESULTS: The spontaneous potential and the insertion potential were increased in the model group, the medication group and the electroacupuncture group after making model. The value of the activation and the relaxed condition of the strength-creep (ARCSC) in the right muscle was significantly decreased. The motor nerve conduction velocity (MNCV) and the wave amplitude of evoked potential (WAEP) were significantly decreased in the model group, the medication group and the electroacupuncture group after treatment, but the value of MNCV and WAEP in the electroacupuncture group, and ARCSC in the right muscle in the electroacupuncture group and the medicine group were closed to those level in the normal group, among them, the relaxed condition in the electroacupuncture group was more close to the level in the normal group. CONCLUSION: Electroacupuncture can improve the strength-creep condition of the muscle that damage nerve place controls and the electrophysiology of the muscle can recover the MNCV and the wave amplitude of evoked potential in the compression nerve root.

Latent membrane protein 1 mediates the resistance of nasopharyngeal carcinoma cells to TRAIL-induced apoptosis by activation of the PI3K/Akt signaling pathway.

The 5-year survival rate of nasopharyngeal carcinoma (NPC) is still disappointing despite the much improved technologies in its treatment. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) can selectively induce apoptosis in most tumor cells while sparing normal cells. However, its potential in the treatment of NPC has been limited by the eventual emergence of drug resistance. Latent membrane protein 1 (LMP1) is a major oncogene of the human DNA tumor virus Epstein-Barr virus (EBV) and is associated with the development of NPC and the emergence of chemo-resistance in NPC. In this study, we investigated the potential role of LMP1 in TRAIL resistance in CNE-1 NPC cells. Results show that overexpression of LMP1 could induce TRAIL resistance in NPC cells without influencing death receptors. The LMP1-induced TRAIL resistance is associated with increased expression of FLIP and elevated cleavage of caspase-8 without altering the TRAIL-mediated mitochondrial events and Bid cleavage. Knockdown of the FLIP gene with siRNA prevented the LMP1-induced TRAIL resistance. Furthermore, we found that overexpression of LMP1 activated Akt. Inhibition of Akt with LY294002 completely prevented the LMP1-induced FLIP expression and TRAIL resistance. Together, these results show that LMP1 can inhibit the TRAIL-mediated apoptosis through activation of PI3K/Akt and expression of FLIP in CNE-1 NPC cells, and may provide new methods to prevent and reverse drug resistance in NPC.

Genes of both parental origins are differentially involved in early embryogenesis of a tobacco interspecies hybrid.

BACKGROUND: In animals, early embryonic development is largely dependent on maternal transcripts synthesized during gametogenesis. However, in higher plants, the extent of maternal control over zygote development and early embryogenesis is not fully understood yet. Nothing is known about the activity of the parental genomes during seed formation of interspecies hybrids. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that an interspecies hybridization system between SR1 (Nicotiana tabacum) and Hamayan (N. rustica) has been successfully established. Based on the system we selected 58 genes that have polymorphic sites between SR1 and Hamayan, and analyzed the allele-specific expression of 28 genes in their hybrid zygotes (Hamayan x SR1). Finally the allele-specific expressions of 8 genes in hybrid zygotes were repeatedly confirmed. Among them, 4 genes were of paternal origin, 1 gene was of maternal origin and 3 genes were of biparental origin. These results revealed obvious biparental involvement and differentially contribution of parental-origin genes to zygote development in the interspecies hybrid. We further detected the expression pattern of the genes at 8-celled embryo stage found that the involvement of the parental-origin genes may change at different stages of embryogenesis. CONCLUSIONS/SIGNIFICANCE: We reveal that genes of both parental origins are differentially involved in early embryogenesis of a tobacco interspecies hybrid and functions in a developmental stage-dependent manner. This finding may open a window to seek for the possible molecular mechanism of hybrid vigor.