Induction and Maintenance of Systemic Acquired Resistance by Acibenzolar-S-Methyl in Three Cultivated Tobacco Types

Induction and maintenance of systemic acquired resistance (SAR) in 'N' gene containing burley, flue-cured, and oriental tobacco cultivars were assessed by monitoring decreases in the number of local lesions caused by Tobacco mosaic virus (TMV) following treatment with acibenzolar-S-methyl (ASM). Leaf samples were collected from lower, middle, and top positions on seedlings at 3-day intervals over 21 days following ASM treatment and subsequent inoculation with TMV under laboratory conditions. Local lesion number for each leaf was recorded 7 days postinoculation. Reductions in TMV local lesion numbers on ASM-treated versus nontreated tobacco varied over time, and differed for each tobacco type. Based on reduced local lesion numbers, SAR was induced in burley and flue-cured tobacco by 3 and 6 days postinoculation, respectively, while oriental tobacco responded by 9 days. SAR was maintained in burley tobacco from 3 to 9 days after ASM application, and from 9 to 15 days after application in oriental tobacco. ASM treatment reduced local lesion numbers in flue-cured tobacco significantly at 6, 12, and 21 days postapplication, but not at 15 and 18 days after treatment. The SAR response was similar among lower, middle, and top leaves with no effect of ASM on response by leaf position, although TMV local lesion numbers were greater on lower leaves than on middle and top leaves 6 days after treatment, but significantly less on lower leaves 18 days after treatment compared to middle and top leaves.

Immune tolerance of skin allograft transplantation induced by immature dendritic cells of a third party carrying donor antigens in mice

BACKGROUND

Dendritic cells (DCs) are the most powerful antigen-presenting cells in the body. Immature DCs (imDCs) can induce transplantation tolerance. In this study, using a mouse model of skin transplantation. We explored the antigen uptake by imDCs, changes in phenotype and function after antigen loading, as well as survival of skin grafts.

METHODS

Mononuclear cells from C57BL/6 mice mixed with a tritiated leucine ([(3)H]Leu) antigen supernate were incubated with Kunming mice imDC and mature DCs. We recorded the expressions of surface molecules that were detected using flow cytometry, mixed lymphocyte reactions, mean survival times, and postoperative morphological changes in skin grafts.

RESULTS

After the addition of allogeneic antigen supernate, the counts per minute of imDCs were significantly higher than those of mature DCs. The expression rates of I(A)/I(E) and CD80 significantly increased on the cell surface of imDCs. The counts per minute of imDCs in mixed lymphocyte reactions in the presence of allogeneic antigens was significantly higher than those of controls. Comparing mean survival times with controls, skin grafts were significantly longer in the imDCs groups from donors or from a third party carrying donor antigens.

CONCLUSIONS

ImDCs display a strong antigen uptake, gradually maturing in terms of phenotype and function after loading. Complementary application of cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin blocks the immune response of imDCs. Both imDCs from the third party carrying donor antigens and those from the donor strain can establish antigen-specific immune tolerance to allogeneic skin grafts.

Immunomodulatory and anti-inflammatory properties of artesunate in experimental colitis

BACKGROUND

Inflammatory bowel disease is a chronic and idiopathic gastrointestinal inflammation mediated by disregulated immune responses. Artemisinin (a chemical from a traditional Chinese herbal medicine Artemisia annua L.) and its derivatives have been proven to exhibit anti-inflammatory and immunomodulatory effects in the treatment of systemic lupus erythematosus and rheumatoid arthritis with low side-effects. This study is aimed to evaluate the potential therapeutic value of artesunate for inflammatory bowel disease.

METHODS

Murine colitis was induced by either oral administration of dextran sulfate sodium salt (DSS) or intrarectal delivery of 2,4,6- trinitrobenzene sulfonic acid (TNBS) or oxazolone. Mice were treated with artesunate (150mg/kg/day). Peritoneal macrophages were stimulated with lipopolysaccharide (LPS) in the presence or absence of artesunate. Changes in cytokines or proteins of interests were analyzed by enzyme-linked immunosorbent assay (ELISA) or SDS-PAGE/Western blot.

RESULTS

Artesunate significantly ameliorated DSS colitis and TNBS colitis (but not oxazolone colitis), including reduced weight loss and disease activity, as well as macroscopic and microscopic colonic injury. The expression of NF-κBp65 and p-IκB-α were reduced in artesunate treated TNBS colitis compared with untreated. The levels of IFN-γ, IL-17, and TNF-α were significantly decreased in artesunate treated TNBS colitis or DSS colitis. Furthermore, in vitro artesunate treatment significantly inhibited TNF-α production by LPS-activated macrophages.

CONCLUSIONS

Artesunate suppresses TNF-α expression in vitro and in vivo as well as T-helper (Th)1/Th17 responses in TNBS colitis model. Our data suggest a novel clinical application of artesunate as a potential therapy for Crohn's disease.

Gene cloning of porcine adiponectin gene from adipose tissue and construction of its eukaryotic expression vector

To clone adiponectin (ADPN) gene from Shaziling porcine adipocyte and construct its eukaryotic expression vector, total RNA was extracted from subcutaneous fatty tissue. One pair of specific primers was designed by Primer 5.0 software according to the sequence of ADPN gene of porcine available in GenBank. The ADPN gene was amplified by PCR from cDNA and cloned into pMD18-T vector to construct recombinant clonal vector pMD-ADPN, sequenced and analysed. A recombinant expression plasmid pPICZaA-ADPN was constructed by subcloning the cloned ADPN gene into the linearized pPICZaA vector. Then, the plasmid pPICZaA-ADPN was expressed in Pichia pastoris (GS115) by electrotransformation. Western blot and Bradford analysis were used to determine the target protein induced by methanol. Results showed that the genome size of ADPN was 732 bp and encoded 244 amino acid, the nucleotide sequence of ADPN shared 100% identity with that of porcine available in GenBank. Western blot and Bradford analysis showed that the recombinant ADPN was expressed in GS115 correctly and has certain immune activity. The expression level of ADPN was 28.5 μg/ml. In conclusion, the recombinant ADPN could express in eukaryotic expression vector pPICZaA-ADPN constructed in this study effectively.

A salicylic acid-induced rice (Oryza sativa L.) transcription factor OsWRKY77 is involved in disease resistance of Arabidopsis thaliana

Plant WRKY transcription factors act as either positive or negative regulators of plant basal disease resistance. To comprehensively characterise the complicated functional network, we isolated OsWRKY77 from rice seedlings treated with salicylic acid. OsWRKY77 is a typical WRKY transcription factor, based on in its protein structure analysis, nuclear localisation of the fused OsWRKY77-GFP protein and gel electrophoretic mobility shift assay binding, which demonstrated that OsWRKY77 was able to bind a W-box. Transgenic Arabidopsis lines overexpressing OsWRKY77 repressed growth of Pseudomonas syringae pv. tomato DC3000 (PstDC300), and the reduced susceptibility was associated with enhanced expression of defence-related PR1, PR2 and PR5 genes. These results show that OsWRKY77 is a positive regulator of PR gene expression and basal resistance to the bacterial pathogen PstDC3000.

Ezrin dephosphorylation/downregulation contributes to ursolic acid-mediated cell death in human leukemia cells

Ezrin links the actin filaments with the cell membrane and has a functional role in the apoptotic process. It appears clear that ezrin is directly associated with Fas, leading to activation of caspase cascade and cell death. However, the exact role of ezrin in ursolic acid (UA)-induced apoptosis remains unclear. In this study, we show for the first time that UA induces apoptosis in both transformed and primary leukemia cells through dephosphorylation/downregulation of ezrin, association and polarized colocalization of Fas and ezrin, as well as formation of death-inducing signaling complex. These events are dependent on Rho-ROCK1 signaling pathway. Knockdown of ezrin enhanced cell death mediated by UA, whereas overexpression of ezrin attenuated UA-induced apoptosis. Our in vivo study also showed that UA-mediated inhibition of tumor growth of mouse leukemia xenograft model is in association with the dephosphorylation/downregulation of ezrin. Such findings suggest that the cytoskeletal protein ezrin may represent an attractive target for UA-mediated lethality in human leukemia cells.

Factors associated with referral to medical oncology and subsequent use of adjuvant chemotherapy for non-small-cell lung cancer: a population-based study

BACKGROUND

Adjuvant chemotherapy (act) for non-small-cell lung cancer (nsclc) is associated with improved survival in the general population, but may be underutilized. We explored the factors associated with referral to medical oncology and subsequent use of act among all patients with resected nsclc in Ontario, Canada.

METHODS

The Ontario Cancer Registry was used to identify all incident cases of nsclc diagnosed in Ontario during 2004-2006. We linked electronic records of treatment and of physician billing to identify surgery, act, and medical oncology consultation. A multivariate logistic regression model was used to evaluate factors associated with referral to medical oncology and subsequent use of act.

RESULTS

Among 3354 cases of nsclc resected in Ontario during 2004-2006, 1830 (55%) were seen postoperatively by medical oncology, and 1032 (31%) were treated with act. Patients more than 70 years of age were less likely than younger patients to have a consultation [odds ratio (or): 0.4; p < 0.001]. A higher proportion of cases with stage ii or iii nsclc than with stage i disease were referred (ors: 2.7, 2.0 respectively; p < 0.005). We observed substantial geographic variation in the proportion of surgical cases referred (range: 32%-88%) that was not explained by differences in case mix. Among cases referred to medical oncology, older patients (age 60-69 years, or: 0.4; age 70+ years, or: 0.1; p < 0.001) with greater comorbidity (Charlson comorbidity index: 3+; or: 0.5; p < 0.05) and a longer postoperative stay (median length of stay: 7+ days; or: 0.7; p = 0.001) were less likely to receive act. Use of act was greater in patients with stage ii or iii than with stage i disease (ors: 3.0, 2.7 respectively; p < 0.001); use also varied with geographic location (range: 46%-63%).

CONCLUSIONS

The initial decision to refer to medical oncology is associated with age and stage of disease, and those factors have an even greater effect on the decision to offer act. Comorbidity and postoperative length of stay were not associated with initial referral, but were associated with use of act in patients seen by medical oncology.

Antitumor effects of interferon-alpha on cell growth and metastasis in human nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a highly malignant and frequently metastasized tumor, and the prognosis is very poor when distant metastases occur. Recently, immunotherapy is becoming a promising therapeutic approach. Interferon-α (IFN-α) represents the cytokines exhibiting the longest record of use in clinical oncology. In this study, we examined the antitumor effects of IFN-α1b on NPC. The results showed that recombinant human IFN-α1b (hIFN-α1b) suppressed cell growth, induced a G1-phase cell cycle arrest in vitro, increased the expression of p16 and pRb, and decreased the expression of CCND1 and CDK6. In vivo analyses showed that either recombinant adeno-associated virus (rAAV)-IFN-α1b or hIFN-α1b treatment inhibited tumor growth and metastasis, reduced intratumoral microvessel density, increased cell apoptosis and necrosis, and induced prolonged survival. Notably, rAAV-IFN-α1b or hIFN-α1b treatment led to significantly higher serum levels of IL-12 and GM-CSF in mice compared to respective controls. Our findings suggest that IFN-α1b acts as a multifunctional antitumor agent in NPC, which may have important therapeutic implications.

Human positive coactivator 4 is a potential novel therapeutic target in non-small cell lung cancer

Transcriptional positive coactivator 4 (PC4) is a multifunctional nuclear protein that has important roles in DNA transcription, replication, repair and heterochromatinization. However, the role of PC4 in cancer remains to be clarified. Several studies propose that PC4 may act as a putative tumor suppressor. Here, we demonstrate for the first time that PC4 may represent a potential therapeutic target in non-small cell lung cancer (NSCLC). PC4 protein expression is significantly upregulated in NSCLC carcinoma tissues compared with their adjacent noncancerous counterparts as shown by immunohistochemical staining and western blotting in 104 pairs of formalin-fixed human NSCLC specimens and 6 fresh NSCLC samples. Knockdown of PC4 expression by sequence-specific small interfering RNA (siRNA) in human NSCLC cells (A549, H460 and H358) significantly inhibits the growth of cancer cells by the induction of cell cycle arrest and the increase of cell apoptosis in vitro. Interrupting the PC4 signaling pathway by injection of the PC4 siRNA liposome complex produced an effective regression of pre-established A549 cell xenografts in mice through growth inhibition and increased apoptosis. These results indicated that PC4 could be an attractive new therapeutic target for the treatment of NSCLC.

Ageing-associated changes in cellular immunity based on the SENIEUR protocol

To investigate ageing-associated changes in cellular immunity, we recruited three groups of healthy subjects based on SENIEUR protocol criteria. In addition, 10 subjects were randomly selected from each group to isolate their T cells from peripheral blood mononuclear cells; T cell proliferation after phytohemagglutinin (PHA) stimulation was determined by methyl thiazolyl tetrazolium assays. There were no marked differences in the absolute numbers of peripheral blood T cells, NK cells or B cells among the three groups (P > 0.05). Also, no significant differences were noted in the numbers of CD4+ cells, CD8+ cells, or the CD4+/CD8+ ratios (P > 0.05). After PHA stimulation, T cell proliferation was markedly increased, with the highest level in group C and the lowest level in group A (P < 0.05). Cytokine-induced killer tumouricidal activities were also dramatically increased, with the highest activity in group C and the lowest activity in group A (P < 0.05). Our findings suggest that the number of immune cells remains unchanged with advanced age. However, there is a trend for decreased cellular immunity with an increase in age.

Tumour biomarker expression relative to age and molecular subtypes of invasive breast cancer

Background:

Quantitative differences in biomarker expression relative to age and molecular subtypes have not been well documented in invasive breast cancer (IBCA).

Methods:

Oestrogen receptor (ER), progesterone receptor (PR), HER2, ki67, p53 and DNA ploidy was performed by image analysis in 162 consecutive IBCAs in women (⩽40 years) and compared with women ⩾50 years (100 cases). Molecular subtypes were defined by immunohistochemistry (IHC).

Results:

Among young women, tumours were frequently ER negative (P=0.01) with lower ER (P<0.00), PR (P=0.03), higher ki67 index (KI) (P=0.01) and p53 (P=0.00) compared with older women. Triple negative was more frequent among young women with frequent lymph node involvement compared with older women. Luminal B among young vs old women showed lower ER (67% vs 88%), PR (32% vs 52%), higher KI (48% vs 34%) and p53 (19% vs 7%). Linear regression model showed increasing KI (P<0.0001) and p53 (P=0.0003) according to the molecular subtypes. Survival difference among subtypes was demonstrated by multivariate analysis (P=0.0092) after adjusting for age, race, tumour size, grade and stage.

Conclusion:

We demonstrated significant differences in biomarker expression relative to age and molecular subtypes. Molecular subtype defined by IHC was an independent prognostic factor.