ELOVL6 deficiency aggravates allergic airway inflammation through the ceramide-S1P pathway in mice

BACKGROUND

Elongation of very-long-chain fatty acids protein 6 (ELOVL6), an enzyme regulating elongation of saturated and monounsaturated fatty acids with C12 to C16 to those with C18, has been recently indicated to affect various immune and inflammatory responses; however, the precise process by which ELOVL6-related lipid dysregulation affects allergic airway inflammation is unclear.

OBJECTIVES

This study sought to evaluate the biological roles of ELOVL6 in allergic airway responses and investigate whether regulating lipid composition in the airways could be an alternative treatment for asthma.

METHODS

Expressions of ELOVL6 and other isoforms were examined in the airways of patients who are severely asthmatic and in mouse models of asthma. Wild-type and ELOVL6-deficient (Elovl6^-/-) mice were analyzed for ovalbumin-induced, and also for house dust mite-induced, allergic airway inflammation by cell biological and biochemical approaches.

RESULTS

ELOVL6 expression was downregulated in the bronchial epithelium of patients who are severely asthmatic compared with controls. In asthmatic mice, ELOVL6 deficiency led to enhanced airway inflammation in which lymphocyte egress from lymph nodes was increased, and both type 2 and non-type 2 immune responses were upregulated. Lipidomic profiling revealed that the levels of palmitic acid, ceramides, and sphingosine-1-phosphate were higher in the lungs of ovalbumin-immunized Elovl6^-/- mice compared with those of wild-type mice, while the aggravated airway inflammation was ameliorated by treatment with fumonisin B1 or DL-threo-dihydrosphingosine, inhibitors of ceramide synthase and sphingosine kinase, respectively.

CONCLUSIONS

This study illustrates a crucial role for ELOVL6 in controlling allergic airway inflammation via regulation of fatty acid composition and ceramide-sphingosine-1-phosphate biosynthesis and indicates that ELOVL6 may be a novel therapeutic target for asthma.

Has2 Regulates the Development of Ovalbumin-Induced Airway Remodeling and Steroid Insensitivity in Mice

HAS2 is a member of the gene family encoding the hyaluronan synthase 2, which can generate high-molecular-weight hyaluronan (HMW-HA). Our previous study identified HAS2 as a candidate gene for increased susceptibility to adult asthma. However, whether HAS2 dysfunction affects airway remodeling and steroid insensitivity is still limited. Therefore, this study aimed to clarify the Has2 dysfunction, triggering severe airway remodeling and steroid insensitivity in a murine model of asthma. Has2 heterozygous-deficient (Has2^+/−) mice and their wild-type littermates have been evaluated in a model of chronic ovalbumin (OVA) sensitization and challenge. Mice present a higher sensitivity to OVA and higher IL-17 release as well as eosinophilic infiltration. RNA sequencing demonstrated the downregulation of EIF2 signaling pathways, TGF-β signaling pathways, and heat shock proteins with Th17 bias in Has2^+/−-OVA mice. The combined treatment with anti-IL-17A antibody and dexamethasone reduces steroid insensitivity in Has2^+/−-OVA mice. Has2 attenuation worsens eosinophilic airway inflammation, airway remodeling, and steroid insensitivity. These data highlight that HAS2 and HMW-HA are important for controlling intractable eosinophilic airway inflammation and remodeling and could potentially be exploited for their therapeutic benefits in patients with asthma.

ROS-Nrf2 pathway mediates the development of TGF-β1-induced epithelial-mesenchymal transition through the activation of Notch signaling

Epithelial-mesenchymal transition (EMT) is a cellular process by which epithelial cells transform to acquire mesenchymal phenotypes. Accumulating evidence indicate the involvement of EMT in the progression of malignant diseases. Notch signaling mediates TGF-β1-induced EMT through direct transcriptional activation of Snai1. The molecular mechanism how TGF-β1 activates Notch signaling, however, remains unknown. In this study, we show a pivotal role for reactive oxygen species (ROS)-Nrf2 pathway in TGF-β1-induced Notch signaling activation and EMT development. TGF-β1 induces Nrf2 activation through ROS production. Inhibiting Nrf2 activation either by reducing ROS levels by N-acetylcysteine or by knocking down of Nrf2 by small interfering RNA attenuated both Notch signaling activation and EMT development. TGF-β1 induced the transcription of Notch4 via Nrf2-dependent promoter activation. In conclusion, our study indicates the ROS-Nrf2 pathway mediates the development of TGF-β1-induced EMT through the activation of Notch signaling.

Polyethylene glycol-based linkers as hydrophilicity reservoir for antibody-drug conjugates

Antibody-drug conjugates (ADCs) are an established therapeutic entity in which potent cytotoxic drugs are conjugated to a monoclonal antibody. In parallel with the great emphasis put on novel site-specific bioconjugation technologies, future advancements in this field also rely on exploring novel linker-drug architectures that improve the efficacy and stability of ADCs. In this context, the use of hydrophilic linkers represents a valid strategy to mask or reduce the inherent hydrophobicity of the most used cytotoxic drugs and positively impact the physical stability and in vivo performance of ADCs. Here, we describe the use of linkers containing monodisperse poly(ethylene glycol) (PEG) moieties for the construction of highly-loaded lysine-conjugated ADCs. The studied ADCs differ in the positioning of PEG (linear or pendant), the bonding type with the antibody (amide or carbamate), and the drug-to-antibody ratio (DAR). These ADCs were first evaluated for their stability in solution under thermal stress, showing that both the drug-linker-polymer design and the nature of the antibody-linker bonding are of great importance for their physical and chemical stability. Amide-coupled ADCs bearing two pendant 12-unit poly(ethylene glycol) chains within the drug-linker structure were the best performing conjugates, distancing themselves from the ADCs obtained with a conventional linear 24-unit PEG oligomer or the linker of Kadcyla®. The pharmacokinetic profiles of amide-linked ADCs, with a linear or pendant configuration of the PEG, were tested in mice in comparison to Kadcyla®. Total antibody pharmacokinetics paralleled the trends in aggregation tendency, with slower clearance rates for the ADCs based on the pendant drug-linker format. The above-mentioned findings have provided important clues on the drug-linker design and revealed that the positioning and configuration of a PEG unit have to be carefully tuned to achieve ADCs with improved stability and pharmacokinetics.

Sulforaphane ameliorates steroid insensitivity through an Nrf2-dependent pathway in cigarette smoke-exposed asthmatic mice

Oxidative stress induced by cigarette smoke and other environmental pollutants contributes to refractory asthma. To better understand the role of smoking in asthma, we investigated the effects of cigarette smoke on allergic airway responses in mice and examined expression of nuclear factor-E2-related factor-2 (Nrf2) and its downstream factors, because Nrf2 is known to play a pivotal role in antioxidant responses. OVA-sensitized and challenged BALB/c mice were exposed to cigarette smoke and then treated with dexamethasone, sulforaphane (an activator of Nrf2), or their combination. Upon exposure to cigarette smoke, Nrf2 and associated transcripts were upregulated in response to oxidative stress, and asthmatic responses were steroid resistant. In OVA-sensitized and challenged mice exposed to cigarette smoke and treated with sulforaphane, Nrf2-mediated antioxidant responses were upregulated to a greater extent, and steroid sensitivity of asthmatic responses was restored. Moreover, the expression and activity of histone deacetylase 2 (HDAC2), a key regulator of steroid responsiveness, was reduced in mice exposed to cigarette smoke, but restored by sulforaphane treatment. No effects of sulforaphane were observed in Nrf2-deficient mice. These findings indicate that cigarette smoke induces steroid unresponsiveness in asthmatic airways, and that sulforaphane restores steroid sensitivity via upregulation of Nrf2 and enhancement of HDAC2 expression and activity. Thus, Nrf2 may serve as a potential molecular target for cigarette smoke-related refractory asthma resistant to steroid therapy.

Notch signaling regulates cell density-dependent apoptosis of NIH 3T3 through an IL-6/STAT3 dependent mechanism

Apoptosis is a physiological process that plays a critical maintenance role in cellular homeostasis. Previous reports have demonstrated that cells undergo apoptosis in a cell density-dependent manner, which is regulated, in part, by signal transducers and activators of transcription (STAT) 3. The molecular mechanisms regulating cell density-dependent apoptosis, however, has not been thoroughly investigated to date. Since Notch signaling is activated via direct cell-to-cell contact and plays a pivotal role in cell fate decisions, we examined the role of Notch signaling in cell density-dependent apoptosis of mouse embryonic fibroblasts NIH 3T3 cells. With the increase in cell density, IL-6 expression was induced, which was necessary for STAT3 activation as well as apoptosis regulation. Notch signaling was also activated in a cell-density dependent manner. Blocking Notch signaling either through siRNA-mediated targeting of Jagged1 expression or γ-secretase inhibitor treatment demonstrated that Notch signaling activation was necessary for IL-6 induction. Constitutive activation of Notch signaling via the overexpression of Notch1 intracellular domain was sufficient for the induction of IL-6, which was mediated via direct transcriptional activation. Taken together, our study indicates that Notch signaling regulates cell density-dependent apoptosis through IL-6/STAT3-dependent mechanism. Consequently, Notch signaling might represent a novel therapeutic target in diseases characterized by dysregulated apoptosis.

Abstract P4-08-07: PIK3CA mutation, reduced AKT serine 473 phosphorylation, and increased ERα serine 167 phosphorylation are positive prognostic indicators in postmenopausal estrogen receptor-positive, HER2-negative early breast cancer

Background: Endocrine therapy is the most important treatment option for women with estrogen receptor (ER)-positive breast cancer. We recently reported that approximately two-thirds of patients who relapsed within 5 years had received anthracyclins and/or taxanes as adjuvant or neoadjuvant chemotherapy in addition to adjuvant endocrine therapy. New strategies, such as signal transduction inhibitors together with endocrine therapy are required to improve survival. PIK3CA mutations are detected in almost 40% of early ER-positive breast cancers, and are therefore the most frequent genetic alterations in this subtype. PIK3CA mutation status is reported to affect activation of AKT and ERα. Moreover, recent studies demonstrate that patients had a better prognosis when tumors expressed ER, androgen receptor (AR), and vitamin D receptor (VDR).

Methods: Expression of AR and VDR, phosphorylation of AKT serine (Ser) 473 (AKT phospho-Ser473) and ERα Ser167 (ERα phospho-Ser167) were examined by immunohistochemistry in ER-positive, HER2-negative early breast cancer tissues. Seventeen mutations in exons 1, 4, 7, 9, and 20 of the PIK3CA gene were detected in genomic DNA extracted from formalin-fixed paraffin-embedded tumor blocks. Correlations between these biological markers and clinicopathological factors and prognosis were analyzed separately in pre- and postmenopausal women.

Results: Levels of AKT phospho-Ser473 were significantly higher in premenopausal women (n = 62) than in postmenopausal women (n = 152) (P < 0.0001 and P = 0.014, respectively). In contrast, expression levels of AR were significantly higher in postmenopausal women than in premenopausal women (P < 0.0001). In premenopausal women, 26 tumors (43%) had a single mutation of PIK3CA gene, and 3 tumors (5%) had mutations at two sites. In postmenopausal women, 64 tumors (44%) had a single PIK3CA mutation, 6 tumors (4%) had mutations at two sites, and one tumor (1%) had mutations at three sites. In premenopausal women, wild type PIK3CA was associated with smaller tumor size, higher ER expression levels, and lower AR expression levels when compared with women in the same cohort with PIK3CA mutant tumors. In postmenopausal women, patients with PIK3CA wild-type tumors had higher Ki67 labeling index, higher AKT phospho-Ser473, and lower ERα phospho-Ser167 when compared to patients with PIK3CA mutant tumors. Postmenopausal women with PIK3CA wild-type tumors had significantly worse disease-free survival than patients with PIK3CA mutant tumors (P = 0.007). In contrast, PIK3CA mutation status was not correlated with survival in premenopausal women. Low levels of AKT phospho-Ser473 and high levels of ERα phospho-Ser167 were strongly associated with increased disease-free survival in postmenopausal women (P = 0.016 and P = 0.0016, respectively).

Conclusion: ERα activation, in addition to PIK3CA mutation, may be biomarkers for highly endocrine-responsive tumors. This would facilitate the selection of postmenopausal ER-positive breast cancer patients who are likely to benefit from endocrine therapy alone from those who are not.

Citation Format: Ishida N, Hatanaka Y, Baba M, Hagio K, Okada H, Hatanaka KC, Matsuno Y, Yamashita H. PIK3CA mutation, reduced AKT serine 473 phosphorylation, and increased ERα serine 167 phosphorylation are positive prognostic indicators in postmenopausal estrogen receptor-positive, HER2-negative early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-08-07.

Defecation-related asthma

We herein report the case of a 39-year-old man with recurrent asthma exacerbations preceded by abdominal cramps with the urge to defecate. The patient had a history of near-fatal asthma associated with these gastrointestinal symptoms starting five years before his admission. He stated that, even when his daily asthma symptoms were under control, he suffered from attacks, especially when he had a strong urge to defecate. Although the contribution of increased parasympathetic tone to the onset of bronchospasms was likely, anticholinergics were not effective. Instead, the patient's symptoms successfully improved following the prophylactic use of laxatives, which might therefore be an appropriate therapeutic option for this type of asthma.

Selective blockade of apoptosis by in vivo electroporation-mediated gene transfer combined with portal infusion of plasmid DNA attenuates liver cirrhosis

AIM

The purpose of the present study was to determine whether in vivo electroporation could achieve selective blockade of apoptosis in a rat liver cirrhosis model.

METHODS

A dimethylnitrosamine (DMN)-induced rat liver cirrhosis model was used. In vivo electroporation was performed after portal vein infusion of plasmid DNA. pFas-Fc plasmid DNA was used to block the apoptotic pathway. pUC/HGF and pCAGGS/EGFP were used as positive and negative controls, respectively. Liver collagen content was evaluated by hydroxyproline assay two weeks after gene transfer. Terminal deoxynucleotidyltransferase dUTP nick end-labeling was simultaneously performed in the liver to evaluate suppression of apoptosis. Survival analysis was performed using 10 rats that received the sFas gene, 10 that received the HGF gene, and 13 that received the GFP gene.

RESULTS

The apoptotic cell index in the DMN-injected liver was significantly lower in rats that received the sFas gene compared with the negative control. The collagen content of the DMN-injected liver was also lower in rats that received the sFas gene compared with the negative control. There was no significant difference in the apoptotic cell index and collagen content of rats that received the sFas and HGF genes. Ten weeks after the initiation of DMN treatment, the survival rates with the sFas, HGF, and GFP genes were 56%, 100%, and 0, respectively.

CONCLUSION

Selective blockade of apoptosis by in vivo electroporation-mediated gene transfer improved the apoptotic cell index, hydroxyproline content, and survival rate. Soluble Fas gene therapy using in vivo electroporation can be a safe and efficient therapy for liver cirrhosis in rats.

Luminal membrane expression of mesothelin is a prominent poor prognostic factor for gastric cancer

Background:

Mesothelin is expressed in various types of malignant tumour, and we recently reported that expression of mesothelin was related to an unfavourable patient outcome in pancreatic ductal adenocarcinoma. In this study, we examined the clinicopathological significance of the mesothelin expression in gastric cancer, especially in terms of its association with the staining pattern.

Methods:

Tissue specimens from 110 gastric cancer patients were immunohistochemically examined. The staining proportion and intensity of mesothelin expression in tumour cells were analysed, and the localisation of mesothelin was classified into luminal membrane and/or cytoplasmic expression.

Results:

Mesothelin was positive in 49 cases, and the incidence of mesothelin expression was correlated with lymph-node metastasis. Furthermore, luminal membrane staining of mesothelin was identified in 16 cases, and the incidence of luminal membrane expression was also correlated with pT factor, pStage, lymphatic permeation, blood vessel permeation, recurrence, and poor patient outcome. Multivariate analysis showed that luminal membrane expression of mesothelin was an independent predictor of overall patient survival.

Conclusion:

We described that the luminal membrane expression of mesothelin was a reliable prognostic factor in gastric cancer, suggesting the functional significance of membrane-localised mesothelin in the aggressive behaviour of gastric cancer cells.

Role of lymph node dissection in the treatment of urothelial carcinoma of the upper urinary tract: multi-institutional relapse analysis and immunohistochemical re-evaluation of negative lymph nodes

AIM

To determine the role of lymph node dissection (LND) in the treatment of urothelial carcinoma (UC) of the upper urinary tract (UUT).

PATIENTS AND METHODS

[Study-1] A retrospective multi-institutional study evaluated 293 patients undergoing predominantly nephroureterectomy for UC of the UUT. Of 293 patients, 267 patients had pure UC and 26 demonstrated other histological components. Regarding the pathological node status, 130 patients had pN0 disease, 141 patients had pNx disease and 22 patients had pN+ disease. The sites of initial recurrence and time to first recurrence were reviewed. The sites of recurrence were classified as locoregional or distant recurrence. The relationship between node status and future recurrence was analyzed. [Study-2] Fifty-one patients treated by nephroureterectomy at Hokkaido University Hospital were included. All had LND and all LNs were negative on hematoxylin and eosin staining. We re-evaluated the presence of micrometastasis in LND specimens by anti-cytokeratin immunohistochemistory.

RESULTS

[Study-1] Of 293 patients, 76 developed disease relapse. Regional lymph node recurrence was the most common site (34 patients). On multivariate analyses that adjusted for the effect of tumor stage and tumor grade, pNx (skipping LND) was an adverse factor not only for locoregional recurrence, but also for distant relapse. [Study-2] Immunohistochemistry identified micrometastases in 7 (14%) of 51 patients. Regarding survival, 5 of these 7 patients with micrometastases were alive at last follow-up.

CONCLUSIONS

On relapse analysis, skipping LND was an adverse factor not only for locoregional recurrence, but also for distant relapse. Immunohistochemistry detected micrometastases in about 14% of patients previously diagnosed as pN0. These findings further support a potential therapeutic benefit of LND by eliminating micrometastases.

DEK oncoprotein regulates transcriptional modifiers and sustains tumor initiation activity in high-grade neuroendocrine carcinoma of the lung

Lung cancer shows diverse histological subtypes. Large-cell neuroendocrine cell carcinoma and small-cell lung carcinoma show similar histological features and clinical behaviors, and can be classified as high-grade neuroendocrine carcinoma (HGNEC) of the lung. Here we elucidated the molecular classification of pulmonary endocrine tumors by copy-number profiling. We compared alterations of copy number with the clinical outcome of HGNEC and identified a chromosomal gain of the DEK oncogene locus (6p22.3) that was significantly associated with poor prognosis. We further confirmed that DEK overexpression was associated with poor prognosis in a larger set of HGNEC. Downregulation of DEK by small hairpin RNA led to a marked reduction of in vitro colony formation, in vivo tumorigenicity and chemo-resistance, and was associated with loss of lung cancer stem cell markers. Gene expression profiling revealed that DEK downregulation was associated with altered expression of transcriptional regulators, which specifically include known targets of interchromosomal translocations in hematopoietic tumors, and knockdown of these epigenetic modifiers affected colony formation activity. Our study showed that DEK overexpression, partly through an increase in its gene dose, mediates the activity of global transcriptional regulators and is associated with tumor initiation activity and poor prognosis in HGNEC.

Toll-like receptor 6 drives interleukin-17A expression during experimental hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a T-cell-driven disease that is histologically characterized by diffuse mononuclear cell infiltrates and loosely formed granulomas in the lungs. We have previously reported that interleukin-17A (IL-17A) contributes to the development of experimental HP, and that the pattern recognition receptor Toll-like receptor 6 (TLR6) might be a factor in the initiation of this response. Using a well-established murine model of Saccharopolyspora rectivirgula-induced HP, we investigated the role of TLR6 in the immunopathogenesis of this disease. In the absence of TLR6 signalling, mice that received multiple challenges with S. rectivirgula-antigen (SR-Ag) had significantly less lung inflammation compared with C57BL/6 mice (wild-type; WT) similarly challenged with SR-Ag. Flow cytometric analysis of whole lung samples from SR-Ag-challenged mice showed that TLR6(-/-) mice had a decreased CD4(+) : CD8(+) T-cell ratio compared with WT mice. Cytokine analysis at various days after the final SR-Ag challenge revealed that whole lungs from TLR6(-/-) mice contained significantly less IL-17A than lungs from WT mice with HP. The IL-17A-driving cytokines IL-21 and IL-23 were also expressed at lower levels in SR-Ag-challenged TLR6(-/-) mice, when compared with SR-Ag-challenged WT mice. Other pro-inflammatory cytokines, namely interferon-gamma and RANTES, were also found to be regulated by TLR6 signalling. Anti-TLR6 neutralizing antibody treatment of dispersed lung cells significantly impaired SR-Ag-induced IL-17A and IL-6 generation. Together, these results indicate that TLR6 plays a pivotal role in the development and severity of HP via its role in IL-17A production.

The indolent course and high incidence of t(14;18) in primary duodenal follicular lymphoma

BACKGROUND

Information on the clinical behavior of the recently proposed primary duodenal follicular lymphoma (DFL) is limited.

PATIENTS AND METHODS

Demographic data, signs, symptoms, disease stage, and treatment of the patients diagnosed in National Cancer Center Hospital from 1999 to 2007 were collected and analyzed.

RESULTS

Twenty-seven patients were studied. Nineteen patients were asymptomatic at the time of diagnosis. Twenty patients had stage I disease. The histological grade was 1 or 2 in 26 patients. IgH/BCL2 fusion was shown in 20 of the examined 24 cases (83%). Fourteen patients received therapy upon diagnosis (local radiotherapy in 2 patients and chemotherapy in 12 including rituximab therapy), their response rate was 85%, and the estimated progression-free survival (PFS) rate at 3 years was 70%. One patient developed histological transformation. The other 13 patients were followed up; their estimated PFS rate at 3 years was 74%. Five among six cases responded to treatment even after progressive disease. All 27 patients have survived with a median follow-up time of 47.9 months.

CONCLUSIONS

The majority of primary DFL patients have a localized tumor of low-grade histology and are positive for t(14;18). Watchful waiting might be an alternative approach for its indolent course; however, further studies are warranted.

RFA for Small Breast Cancer — What Tumor Can Be Treated Safely?

Breast conserving surgery for small breast cancer has been acceptable as one of standard treatments. However, there are some patients who do not be satisfied with the cosmesis. The aim of this study is to verify the clinical safety and usefulness of the RadioFrequency Ablation (RFA) for small breast cancer without resection. Between January 2006 and Octobar 2007, 20 breast cancer patients were performed RFA with cool-tip RF system after sentinel LN biopsy under general anesthesia. All patients has consented as a clinical research, beforehand. MR mammography was performed after 3 and 6 months of follow-up. All patients were performed postoperative histological examination by 8G-needle mammotome biopsy after 6 months MRI evaluation.Tumor viability after RFA was assessed by hematoxylin -eosin and ssDNA staining. QOL after RFA was assessed both subjectively(QOL-ACD score) and objectively(JBCS cosmesis criterion). Preoperative mammotome revealed 4 patients had DCIS and 16 patients had IDC. The patients median age was 53 years old. The mean greatest dimension of tumors was 1.0 cm (range, 0.5-1.5 cm). MRI showed the dimention of coagulation necrotic area by RFA treatment was 3.5cm (range, 2.5-5.4 cm).All patients have been performed postoperative histlogical examination by 8G mammtome biopsy 6 month after RFA treatment. Coagulation necrosis of the tumor was complete in 20of 20 patients (100%).No patient was troubled skin burn. Neither local and distant recurrence has occurred in all patients (median follow up was 30 month). To treat RFA for breast cancer more safely, we analyzed factors which influenced the size of necrosis. Patient age, body mass index (BMI), background concentration measured by MMG, Fat involvement measured by CT did not influence with the size of nectosis (P=0.21,0.17,0.64,0.40). The state of posterior echo detected by ultrasonography was associated with the size of necrosis (p=0.045). Hence, RFA for the tumor with rich fiber such as scirrhous type tend to make necrosis wider than one with poor fiber such as solid tubular type.Most of patients were satisfied with the cosmesis of the RFA treated breast. Objective QOL score (JBCS cosmesis criterion) showed splendid cosmetic outcome. RFA is one of the effective local treatment for small breast cancer (< 1.5 cm in diameter), and bring breast cancer patients cosmetic satisfaction.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4119.

Sucutiniranes C-F, cassane-type diterpenes from Bowdichia nitida

Four new cassane-type diterpenes, sucutiniranes C-F (3-6), have been isolated from seeds of Bowdichia nitida, and their structures were elucidated by using 2D NMR data, chemical correlations, and X-ray analysis. Sucutiniranes E (5) and F (6) were moderately cytotoxic against human blood premyelocytic leukemia (HL-60), breast adenocarcinoma (MCF-7), and colon cancer (HCT-116) cells.

Nrf2 enhances cell proliferation and resistance to anticancer drugs in human lung cancer

PURPOSE

NF-E2-related factor 2 (Nrf2), a key transcription regulator for antioxidant and detoxification enzymes, is abundantly expressed in cancer cells. In this study, therefore, the role of Nrf2 in cancer cell proliferation and resistance to anticancer drugs was investigated.

EXPERIMENTAL DESIGN

We used three human lung cancer cell lines with different degrees of Nrf2 activation: Nrf2 was highly activated in A549 cells, slightly activated in NCI-H292 cells, and not activated in LC-AI cells under unstimulated conditions.

RESULT

A549 cells showed higher resistance to cisplatin compared with NCI-H292 and LC-AI cells. The resistance to cisplatin was significantly inhibited in A549 but not in NCI-H292 or LC-AI cells by knockdown of Nrf2 with its specific small interfering RNA (Nrf2-siRNA). The cell proliferation was also most prominently inhibited in A549 cells by treatment with Nrf2-siRNA. In A549 cells, the expression of self-defense genes, such as antioxidant enzymes, phase II detoxifying enzymes, and drug efflux pumps, was significantly reduced by Nrf2-siRNA concomitant with a reduction of the cellular glutathione level. The degree of DNA crosslink and apoptosis after treatment with cisplatin was significantly elevated in A549 cells by Nrf2-siRNA. Knockdown of Nrf2 arrested the cell cycle at G(1) phase with a reduction of the phosphorylated form of retinoblastoma protein in A549 and NCI-H292 cells but not in LC-AI cells.

CONCLUSION

These results indicate that the Nrf2 system is essential for both cancer cell proliferation and resistance to anticancer drugs. Thus, Nrf2 might be a potential target to enhance the effect of anticancer drugs.

Prognostic impact of para-aortic lymph node micrometastasis in patients with regional node-positive biliary cancer

BACKGROUND

The presence of para-aortic lymph node metastasis in biliary cancer has a negative impact on prognosis. The relevance of para-aortic lymph node micrometastasis is unknown.

METHODS

A total of 546 para-aortic lymph nodes from 49 patients with biliary cancer with positive regional nodes and negative para-aortic nodes were immunostained with epithelial marker CAM5.2 (specific for cytokeratins 7 and 8). Immunostained tumour foci were classified as micrometastases or isolated tumour cells (ITCs) according to their size (larger or smaller than 0.2 mm).

RESULTS

CAM5.2-positive occult carcinoma cells in para-aortic lymph nodes were detected in nine (18 per cent) of 49 patients and in 18 (3.3 per cent) of 546 para-aortic nodes. There was no difference in postoperative survival between patients with and without CAM5.2-positive para-aortic nodes (P = 0.978), but survival for five patients with micrometastases was significantly worse than that for four patients with only ITCs (P = 0.047).

CONCLUSION

In patients with regional node-positive and para-aortic node-negative biliary cancer, and occult cancer cells in para-aortic lymph nodes, prognosis was significantly worse in those with micrometastases than in patients with only ITCs. An efficient method of intraoperative detection of para-aortic lymph node micrometastases larger than 0.2 mm is needed.

[Three-dimensional demonstration of the spinal cord artery with 64-row computed tomography]

This is a report of 2 cases, in which preoperative 3-dimentional demonstration of the spinal cord artery with 64-row computed tomography was feasible, less invasive, less time-consuming, and helpful in making an interventional strategy for complex aortic disease, resulting in no postoperative paraplegia One was a 63-year-old man, who underwent total arch replacement and a long elephant trunk method for arch and descending aortic aneurysms. The length of the long elephant trunk was so determined that it ended between the descending aortic aneurysm and the origin of the spinal cord artery. The second case was a 59-year-old man, who underwent descending thoracic aorta replacement for type B aortic dissection. During the distal anastomosis, the dissection septa were trimmed in order to perfuse the blood into the true and 2 false channels, one of which was connected to the spinal cord artery. In this report, we are not suggesting that preservation of the demonstrated spinal cord artery is enough for spinal cord protection, because it is still controversial. Further study is needed to confirm the reliability and reproducibility of our methods.

Overexpression of GATA-3 Protects against the Development of Hypersensitivity Pneumonitis

RATIONALE

Hypersensitivity pneumonitis (HP) is mediated by a Th1 immune response. Transcription factor GATA binding protein-3 (GATA-3) is believed to be a key regulator of Th2 differentiation and thus might play regulatory roles in the pathogenesis of hypersensitivity pneumonitis (HP).

OBJECTIVES

We examined the effect of GATA-3 overexpression on the development of HP in mice.

METHODS

Wild-type C57BL/6 mice and GATA-3-overexpressing mice of the same background were used in this study. HP was induced by repeated exposure to Saccharopolyspora rectivirgula, the causative antigen of farmer's lung.

MEASUREMENTS AND MAIN RESULTS

Antigen exposure resulted in a marked inflammatory response with enhanced pulmonary expression of T-bet and the Th1 cytokine interferon (IFN)-gamma in wild-type mice. The degree of pulmonary inflammation was much less severe in GATA-3-overexpressing mice. The induction of T-bet and IFN-gamma genes was suppressed, but a significant induction of Th2 cytokines, including IL-5 and IL-13, was observed in the lungs of GATA-3-overexpressing mice after antigen exposure. Supplementation with recombinant IFN-gamma enhanced lung inflammatory responses in GATA-3-overexpressing mice to the level of wild-type mice. Because antigen-induced IFN-gamma production predominantly occurred in CD4+ T cells, nude mice were transferred with CD4+ T cells from either wild-type or GATA-3-overexpressing mice and subsequently exposed to antigen. Lung inflammatory responses were significantly lower in nude mice transferred with CD4+ T cells from GATA-3-overexpressing mice than in those with wild-type CD4+ T cells, with a reduction of lung IFN-gamma level.

CONCLUSIONS

These results indicate that overexpression of GATA-3 attenuates the development of HP by correcting the Th1-polarizing condition.

Taxodistines A and B, abietane-type diterpenes from Taxodium distichum

Two new abietane-type diterpenes, taxodistines A (1) and B (2), have been isolated by the guidance of inhibitory effect of tubulin polymerization from the fruits of Taxodium distichum and the structures were elucidated by using 2D NMR data. Taxodistine B (2) showed inhibition of tubulin polymerization.

Pordamacrines A and B, alkaloids from Daphniphyllum macropodum

The new Daphniphyllum alkaloids, pordamacrines A (1) and B (2), have been isolated from the leaves of Daphniphyllum macropodum, and their structures were elucidated on the basis of interpretation of spectroscopic data and by the single-crystal X-ray diffraction analysis of 2. Pordamacrines A (1) and B (2) exhibited moderate vasorelaxant effects on the rat aorta.

Niflumic acid and AG-1478 reduce cigarette smoke-induced mucin synthesis: the role of hCLCA1

BACKGROUND

Cigarette smoke induces bronchial mucus secretion. However, the mechanism of this induction is still unidentified. In this study, we investigated the role of the putative calcium-activated chloride channel 1 (CLCA1) and its blocker, niflumic acid, in cigarette smoke-induced mucin synthesis both in vivo and in vitro.

METHODS AND RESULTS

Sprague-Dawley rats were exposed to cigarette smoke for 4 weeks. The CLCA1, epidermal growth factor receptor (EGFR), and MUC5AC expressions were increased in the trachea and lung tissues. Goblet-cell hyperplasia with marked mucin staining was detected in the tracheal and bronchial epithelium. In the human bronchial epithelial cell line NCI-H292, cigarette smoke solution also induced mucin production as well as the RNA and protein expressions of CLCA1, EGFR, and MUC5AC. Both in vivo and in vitro, the induction of MUC5AC and mucin synthesis were inhibited by niflumic acid, and/or a selective EGFR tyrosine kinase inhibitor, AG-1478. Niflumic acid also blocked the epidermal growth factor-induced MUC5AC and mucin staining in the NCI-H292 cell line.

CONCLUSION

Both EGFR and niflumic acid-sensitive chloride channels (probably CLCA1) are dependently affecting the mucin production as a part of a single complex signaling pathway. CLCA1 may be a key signaling member that can be targeted with pharmacologic interventions to treat mucus hypersecretion.

Prevalence and specificity of LKB1 genetic alterations in lung cancers

Germline LKB1 mutations cause Peutz-Jeghers syndrome, a hereditary disorder that predisposes to gastrointestinal hamartomatous polyposis and several types of malignant tumors. Somatic LKB1 alterations are rare in sporadic cancers, however, a few reports showed the presence of somatic alterations in a considerable fraction of lung cancers. To determine the prevalence and the specificity of LKB1 alterations in lung cancers, we examined a large number of lung cancer cell lines and lung adenocarcinoma (AdC) specimens for the alterations. LKB1 genetic alterations were frequently detected in the cell lines (21/70, 30%), especially in non-small cell lung cancers (NSCLCs) (20/51, 39%), and were significantly more frequent in cell lines with KRAS mutations. Point mutations were detected only in AdCs and large cell carcinomas, whereas homozygous deletions were detected in all histological types of lung cancer. Among lung AdC specimens, LKB1 mutations were found in seven (8%) of 91 male smokers but in none of 64 females and/or nonsmokers, and were significantly more frequent in poorly differentiated tumors. The difference in the frequency of LKB1 alterations between cell lines and tumor specimens was likely to be owing to masking of deletions by the contamination of noncancerous cells in the tumor specimens. These results indicate that somatic LKB1 genetic alterations preferentially occur in a subset of poorly differentiated lung AdCs that appear to correlate with smoking males.

Whitham method for the Benjamin-Ono-Burgers equation and dispersive shocks

The Whitham modulation equations for the parameters of a periodic solution are derived using the generalized Lagrangian approach for the case of the damped Benjamin-Ono equation. The structure of the dispersive shock is considered in this method.

[A case of pulmonary arteriovenous fistula]

A 31-year-old man presenting with abrupt onset of convulsions was transported by ambulance to a nearby neurosurgery hospital. Imaging examination of the brain revealed a brain abscess in the left parietal lobe. Surgical excision of the abscess was performed. After the operation, the patient was referred to our hospital because of abnormal radio-opacities on the chest X-ray film, which were subsequently diagnosed to represent pulmonary arteriovenous fistulae in the lower lobes of both lungs. The fistulae were successfully embolized with detachable coils. Orthodeoxia (worsening of hypoxemia on assuming the upright from the supine position) was confirmed by measuring the partial pressure of oxygen in the arterial blood. We examined the shunt ratio by both the 100% O2 inhalation and 99mTc-MAA methods, and a higher ratio was obtained with the radioisotope method than with the 100% O2 inhalation method. Although it is known that the 99mTc-MAA method is more precise than the 100% O2 inhalation method, the latter is easier to perform and therefore more useful in practical clinical situations.

Postoperative Incision Hernia in Patients with Abdominal Aortic Aneurysm and Aortoiliac Occlusive Disease: A Systematic Review

OBJECTIVES

We conducted a systematic review to determine the incidence of postoperative incision hernia in patients with abdominal aortic aneurysm compared to those with aortoiliac occlusive disease.

METHODS

Studies which compared the incidence of postoperative incision hernia in patients with abdominal aortic aneurysm and aortoiliac occlusive disease undergoing midline incision for arterial reconstruction were identified. MEDLINE was searched for articles published between January 1966 and September 2005.

RESULTS

Our search identified seven studies including data on 1132 patients, 719 with abdominal aortic aneurysm and 413 with aortoiliac occlusive disease. Pooled analysis demonstrated that patients with abdominal aortic aneurysm had a 2.9-fold increased risk of inguinal hernia (odds ratio 2.85, 95% confidence interval 1.71-4.77, p<0.0001), and a 2.8-fold risk of incisional hernia (2.79, 1.88-4.13, p<0.0001). Adjusting for other known risk factors patients with aortic aneurysm had a 5-fold increased risk of incisional hernia (5.45, 2.48-11.94, p<0.0001).

CONCLUSIONS

Patients with abdominal aortic aneurysm appear to have an approximately 3-fold increased risk for both inguinal and postoperative incision hernia compared to patients with aortoiliac occlusive disease. A large multi-centre prospective study is needed to confirm the results of this review.