Viral stimulation modulates endotype-related ACE2 expression in eosinophilic chronic rhinosinusitis

BACKGROUND

Angiotensin-converting enzyme 2 (ACE2), a receptor targeted by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is highly expressed in the nasal mucosa. Chronic rhinosinusitis (CRS) shows diverse endotypes and is aggravated by viral infection. Whether viral stimulation and CRS endotype influence ACE2 expression remains unclear. We investigated the expression of ACE2 and the transmembrane protease, serine 2 (TMPRSS2), which mediate the entry of SARS-CoV-2 into cells, and assessed polyinosinic:polycytidylic acid (poly[I:C])-induced changes based on CRS endotype.

METHODOLOGY

ACE2 and TMPRSS2 expression was evaluated based on CRS phenotype, endotype, and tissue type. Correlations between ACE2/TMPRSS2 expression and inflammatory mediators in nasal polyps (NP) were examined. Air-liquid interface culture experiments were performed to assess the effects of major cytokines or poly(I:C) stimulation on ACE2/TMPRSS2 expression in primary epithelial cells from healthy nasal mucosa, eosinophilic NP (ENP), and non-eosinophilic NP (NENP).

RESULTS

In primary nasal epithelial cells, interleukin (IL)-13 decreased ACE2 expression but increased TMPRSS2. Eosinophilic CRS showed lower ACE2 expression than non-eosinophilic CRS, regardless of CRS phenotype. CRS endotype was an independent factor associated with ACE2/TMPRSS2 expression in NP. Serum and tissue eosinophilic marker levels were inversely correlated with ACE2 expression, whereas tissue neutrophilic marker levels and ACE2 expression were positively correlated in NP. ACE2 expression was suppressed in ENP tissues; however, a combination of poly(I:C) and IL-13 induced ACE2/TMPRSS2 upregulation in ENP.

CONCLUSIONS

ENP tissues have lower ACE2 expression than NENP; however, viral stimulation promotes ACE2/TMPRSS2 upregulation in ENP.

Prenylflavonoids isolated from Macaranga tanarius stimulate odontoblast differentiation of human dental pulp stem cells and tooth root formation via the mitogen-activated protein kinase and protein kinase B pathways

AIM

To identify odontogenesis-promoting compounds and examine the molecular mechanism underlying enhanced odontoblast differentiation and tooth formation.

METHODOLOGY

Five different nymphaeols, nymphaeol B (NB), isonymphaeol B (INB), nymphaeol A (NA), 3'-geranyl-naringenin (GN) and nymphaeol C (NC) were isolated from the fruit of Macaranga tanarius. The cytotoxic effect of nymphaeols on human DPSCs was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effect of nymphaeols on odontoblast differentiation was analysed with Alizarin Red S staining and odontoblast marker expression was assessed using real-time polymerase chain reaction and Western blot analysis. The molecular mechanism was investigated with Western blot analysis. In order to examine the effect of INB on dentine formation in the developing tooth germ, INB-soaked beads were placed under the tooth bud explants in the collagen gel; thereafter, the tooth bud explant-bead complexes were implanted into the sub-renal capsules for 3 weeks. Tooth root formation was analysed using micro-computed tomography and histological analysis. Data are presented as mean ± standard error (SEM) values of three independent experiments, and results are compared using a two-tailed Student's t-test. The data were considered to have statistical significance when the P-value was less than 0.05.

RESULTS

Three of the compounds, NB, INB, and GN, did not exert a cytotoxic effect on human DPSCs. However, INB was most effective in promoting the deposition of calcium minerals in vitro (P < 0.001) and induced the expression of odontogenic marker genes (P < 0.05). Moreover, this compound strongly induced the phosphorylation of mitogen-activated protein (MAP) kinases and protein kinase B (AKT) (P < 0.05). The inhibition of p38 MAP, c-Jun N-terminal kinase (JNK), and AKT substantially suppressed the INB-induced odontoblast differentiation (P < 0.001). In addition, isonymphaeol B significantly induced the formation of dentine and elongation of the tooth root in vivo (P < 0.05).

CONCLUSIONS

Prenylflavonoids, including INB, exerted stimulatory effects on odontoblast differentiation and tooth root and dentine formation via the MAP kinase and AKT signalling pathways. These results suggest that nymphaeols could stimulate the repair processes for dentine defects or injuries.

Clinical Characteristics of Developmentally Delayed Children based on Interdisciplinary Evaluation

The aim of this study is to examine the clinical characteristics of children suspected to have neurodevelopmental disorders and to present features that could be helpful diagnostic clues at the clinical assessment stage. All children who visited the interdisciplinary clinic for developmental problems from May 2001 to December 2014 were eligible for this study. Medical records of the children were reviewed. A total of 1,877 children were enrolled in this study. Most children were classified into four major diagnostic groups: global developmental delay (GDD), autism spectrum disorder (ASD), developmental language disorder (DLD) and motor delay (MD). GDD was the most common (43.9%), and boys were significantly more predominant than girls in all groups. When evaluating the predictive power of numerous risk factors, the probability of GDD was lower than the probability of ASD among boys, while the probability of GDD increased as independent walking age increased. Compared with GDD and DLD, the probability of GDD was increased when there was neonatal history or when the independent walking age was late. Comparison of ASD and DLD showed that the probability of ASD decreased when a maternal history was present, whereas the probability of ASD increased with male gender. To conclude, the present study revealed the clinical features of children with various neurodevelopmental disorders. These results are expected to be helpful for more effectively flagging children with potential neurodevelopmental disorders in the clinical setting.

Abstract PD7-11: Therapeutic strategy for ESR1 mutation driven-endocrine resistance in ER-positive breast cancers

Background: Endocrine therapy is used in estrogen receptor (ER)-positive breast cancers, however, 25% of these patients are at risk of distant relapse and the development of acquired endocrine resistance. Recently mutations in the ER gene (ESR1) have been validated to be acquired during the development of endocrine resistance. The most frequent ESR1 mutation, Y537S, promotes ligand-independent ER activity and emerges subclonally during aromatase inhibitor treatment. In this study, we examined the effects of the Y537S ESR1 mutation on cell cycle signaling and therapeutic response to a novel checkpoint inhibitor.

Material and Methods: MCF-7 cells expressing the Y537S ESR1 mutation were generated by CRISPR-Cas9 knock-in techniques. Cells were incubated in steroid deprived conditions. Cell cycle analysis and apoptosis were examined by flow cytometry annnexin-V assays. Proliferation was analyzed by BrdU incorporation. Cell cycle checkpoint kinases were examined by western blot analysis. Cell growth was analyzed using soft agar and MTT assays. Replication stress was identified by RPA32 and gamma-H2AX foci formation assay. For in vivo studies, MCF-7 ESR1 Y537S mutant cells were injected into female athymic nude mice with 17β-estradiol (E2) supplemented water. When tumors reached 350 mm3, tamoxifen (20 mg/kg; s.c.; three times a week), fulvestrant (200 mg/kg; s.c; once a week) and/or PF477736 Chk1 inhibitor (7.5 mg/kg; i.p.; twice a day and twice a week) was treated without E2.

Results: ESR1 Y537S mutant cells accumulated approximately 5 fold in S phase and 1.7 fold in G2/M phase compared to control cells in estrogen-deprived (ED) conditions. BrdU incorporation also increased about 2.5-fold, however, apoptosis was decreased about 60 % compared with wild-type ER parental cells. ESR1 Y537S mutant cells induced significant replication stress, showing increased RPA32 foci together with increased gamma H2AX foci, a marker of DNA double-stranded breaks. ChIP-seq analysis revealed binding sites on ATR and CHEK1 genomic locations. ATR/Chk1-mediated checkpoint signaling was activated in ESR1 Y537S mutant cells, and was repressed with fulvestrant, tamoxifen, or ESR1 siRNA treatment. The Chk1 inhibitor, PF477736, sensitized MCF-7 expressing the ESR1 Y537S mutation to endocrine treatments such as fulvestrant, tamoxifen, and the ER degrader AZD9496 in cell proliferation assays. In MCF-7 ESR1 Y537S mutant xenograft and patient derived mouse models, tamoxifen treatment combined with the Chk1 inhibitor PF477736 repressed primary xenograft tumor doubling times (P=0.038, Wilcoxon test). Treatment of mutant tumors with PF477736 together with fulvestrant significantly inhibited the frequency of distant lung metastases by 80% (P=0.0031, t-test), suggesting that these combinations may be useful in second line treatment of metastatic breast cancer patients resistant to endocrine therapies.

Conclusion: These preclinical results suggest that ESR1 mutant tumors have a therapeutic vulnerability to combination endocrine therapy with cell cycle checkpoint kinase inhibitors. These data demonstrate that this new therapeutic approach may be useful to restore endocrine sensitivity in metastatic breast cancer patients with ESR1 mutation driven-endocrine resistance.

Citation Format: Kim J-A, Dustin D, Gu G, Corona-Rodriguez A, Edwards D, Coarfa C, Keyomarsi K, Fuqua SA. Therapeutic strategy for ESR1 mutation driven-endocrine resistance in ER-positive breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD7-11.

Endophytic and endolichenic fungal diversity in maritime Antarctica based on cultured material and their evolutionary position among Dikarya

Fungal endophytes comprise one of the most ubiquitous groups of plant symbionts. They live asymptomatically within vascular plants, bryophytes and also in close association with algal photobionts inside lichen thalli. While endophytic diversity in land plants has been well studied, their diversity in lichens and bryophytes are poorly understood. Here, we compare the endolichenic and endophytic fungal communities isolated from lichens and bryophytes in the Barton Peninsula, King George Island, Antarctica. A total of 93 fungal isolates were collected from lichens and bryophytes. In order to determine their identities and evolutionary relationships, DNA sequences of the nuclear internal transcribed spacer (ITS), nuclear ribosomal small subunit (nuSSU), nuclear large subunit (nuLSU), and mitochondrial SSU (mtSSU) rDNA were obtained and protein coding markers of the two largest subunit of RNA polymerase II (RPB1 and RPB2) were generated. Multilocus phylogenetic analyses revealed that most of the fungal isolates were distributed in the following six classes in the phylum Ascomycota: Dothideomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, Pezizomycetes and Sordariomycetes. For the first time we report the presence of subphylum Mortierellomycotina that may belong to an undescribed order in endophytic fungi. Taken together, our results imply that lichens and bryophytes provide similar niches and harbour a selection of these fungi, indicating generalists within the framework of evolutionary adaptation.

Wogonin, a flavonoid isolated from Scutellaria baicalensis, has anti-viral activities against influenza infection via modulation of AMPK pathways

Wogonin, a flavonoid isolated from Scutellaria baicalensis, has attracted increasing scientific attention in recent years because of its potent anti-tumor activity. Its role during viral infection has largely been unexplored. Wogonin treatment effectively suppressed both influenza A and B virus replication in Madin-Darby Canine Kidney (MDCK) cells and human lung epithelial (A549) cells. In contrast, wogonin treatment following influenza A virus infection led to up-regulation of interferon (IFN)-induced antiviral signaling. Additionally, influenza A virus infection in A549 cells induced 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and activation in a time-dependent manner and wogonin treatment led to the suppression of AMPK phosphorylation. Furthermore, the treatment with AMPK-specific inhibitor (compound C; CC) attenuated influenza A virus replication. These data suggest that wogonin possesses a potent anti-influenza activity mediated by regulation of AMPK activation, suggesting that wogonin has the potential to be developed as an anti-influenza drug.

Pretreatment MRI features associated with diagnostic accuracy of post-treatment MRI after neoadjuvant chemotherapy

AIM

To investigate whether pretreatment magnetic resonance imaging (MRI) features are associated with diagnostic accuracy of post-treatment MRI for predicting pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in patients with breast cancer.

MATERIALS AND METHODS

From January 2005 and December 2016, 221 consecutive patients (mean age, 50 years; range, 20-81 years) who had undergone NAC, breast MRI before and after NAC, and surgery for invasive breast cancer were enrolled. Pretreatment and post-treatment MRI images were reviewed. Radiological complete response (rCR) was defined as the absence of both early and late enhancement on MRI after NAC. The association of pretreatment MRI features and post-treatment MRI diagnostic accuracy was assessed by using logistic regression analysis.

RESULTS

Among 221 patients, 60 (27.1%) underwent pCR after NAC. The diagnostic accuracy of post-treatment MRI was 84.2% (186/221). False-positive diagnosis occurred in 21 cases and false-negative diagnosis occurred in 14 cases. Of pretreatment features, the presence of peritumoural oedema (odds ratio, 3; 95% confidence interval [CI]: 1.1, 8.0; p=0.03) and HER2 (human epidermal growth factor receptor 2)-positive status (odds ratio, 3.4; 95% CI: 1.2, 9.9; p=0.02) were significantly associated with false-positive MRI results. Dense fibroglandular tissue (odds ratio, 10.8; 95% CI: 1.1, 105.2; p=0.04), presence of rim enhancement (odds ratio, 7.5; 95% CI: 1.2, 38.3; p=0.02) and oestrogen receptor (ER)-positive status (odds ratio, 6.3; 95% CI: 1.2, 32.5; p=0.03) were significantly associated with false-negative MRI results.

CONCLUSION

Pretreatment MRI features and cancer subtypes may be associated with diagnostic accuracy of post-treatment MRI after NAC in patients with breast cancer.

Abstract P3-06-03: Dual p38/NLK kinase inhibitor as potential novel therapeutic agent for tamoxifen-resistant luminal breast cancer

Background: Tamoxifen is the most commonly used endocrine agent for estrogen receptor (ER) positive breast cancer (also known as luminal breast cancer). However, approximately half of the patients develop resistance after initial response to tamoxifen. To date, no effective targeted therapy exists to overcome it. We previously identified the role of nemo-like kinase (NLK), a serine-threonine kinase that functions in stress response and neurite outgrowth, in breast endocrine resistance. In addition, activation of p38 MAPK has been reported to modulate ER signaling and promote endocrine resistance. We identified a highly selective dual p38 and NLK kinase inhibitor (PNKI) through analysis of public kinase profiling datasets, and evaluated its therapeutic effect in endocrine-resistant breast cancers using in vitro and in preclinical mouse models. Experimental design and methods: To determine the in vitro therapeutic window of PNKI, we treated an acquired tamoxifen-resistant cell line (MCF7-TamR) and a benign breast epithelial cell line (MCF10A) with gradually increasing doses of PNKI. To determine the effect of PNKI on tamoxifen-resistant breast cancer cells, we treated primary tamoxifen-resistant breast cancer cell line BT483, and MDAMB415, together with acquired tamoxifen-resistant line MCF7 TamR, T47D TamR, and ZR-75-B TamR, with 0.5 uM PNKI in the presence of different doses of Tamoxifen. To evaluate the therapeutic effect of PNKI in a T47D-derived xenograft tumor model with acquired tamoxifen resistance, we administered PNKI alone or in combination with Fulvestrant, the second-line endocrine therapy agent, or with Everolimus, the mTOR inhibitor that could improve patient outcomes in several clinical trials. Mice bearing xenografts were randomized into six treatment groups (Vehicle, PNKI, Fulvestrant, Fulvestrant+PNKI, Everolimus, Everolimus+PNKI). Tumor growth was tracked closely. The tumors harvested two weeks after treatments started were profiled with Reverse Phase Protein Array (RPPA) to assess the early signaling changes after treatments. The therapeutic effect of PNKI were also evaluated in a patient-derived xenograft (PDX) model of de novo endocrine resistant breast cancer. Mice bearing the PDX tumors were randomized to four treatment groups (Vehicle, PNKI, Everolimus, Everolimus+PNKI) and tumor growth curve was measured timely. Results: PNKI showed an in vitro therapeutic window at 0.1-1μM for MCF7-TamR cells. Breast cancer cell lines with either de novo or acquired Tamoxifen resistance became more sensitive to tamoxifen when treated with 0.5uM PNKI. The concomitant treatment of PNKI and Everolimus results in significant decreased tumor burden and prolonged progression free survival in the both T47D-TamR xenograft tumors and re-transplanted de novo endocrine-resistant PDX tumors compared to other treatments. RPPA data of T47D-TamR tumors harvested following 2-week treatments revealed that several key survival signaling in breast cancer are repressed only when PNKI are combined with Everolimus. Conclusion: The dual p38 and NLK inhibitor (PNKI) exhibited potential therapeutic value as adjuvant agent to the mTOR inhibitor everolimus for acquired or de novo tamoxifen-resistant luminal breast cancers.

Citation Format: Wang X, Cao X, Veeraraghavan J, Qin L, Kim J-A, Tan Y, Hilsenbeck SG, Schiff R, Wang X. Dual p38/NLK kinase inhibitor as potential novel therapeutic agent for tamoxifen-resistant luminal 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 P3-06-03.

Abstract P4-04-08: Therapeutic strategy for ERα mutation driven-endocrine resistance in ER-positive breast cancers

Background: Although estrogen receptor (ER)-positive breast cancers are treated with endocrine therapy, 25% of these patients are at risk of relapse and the development of acquired endocrine resistance. Recently mutations in the ER gene (ESR1) have been identified which induce resistance to endocrine therapy. The most frequent ESR1 mutation, Y537S, promotes ligand-independent ER activity. It is known that ER regulates the cell cycle in a ligand-dependent manner. In this study, we examined the effects of the Y537S ESR1 mutation on cell cycle signaling and therapeutic response to checkpoint inhibitor.

Material and Methods: MCF-7 cells expressing the Y537S ESR1 mutation were generated by CRISPR-Cas9 knock-in techniques. Cells were incubated in phenol red minus medium containing 5% charcoal-dextran treated serum for 5 days to remove exogenous hormones. Cell cycle and apoptosis were examined by Flow cytometry and Annexin-V assays. Proliferation was analyzed by BrdU incorporation. Cell senescence was determined using beta-galactosidase assays. Cell cycle checkpoint kinases were examined by western blot analysis. Cell growth was analyzed using soft agar or MTT assays.

Results: Levels of p53 and apoptosis pathway proteins were significantly elevated in Y537S ESR1 mutant cells using RNA expression and reverse-phase protein microarrays. The ATM/ATR and Chk1/Chk2 mediated checkpoint signaling, the upstream pathway of p53, was activated in ESR1 Y537S mutation, which was repressed with fulvestrant treatment. ESR1 Y537 mutant cells accumulated about 5 fold in S phase and 1.7 fold in G2/M phase compared to control cells in estrogen deprived (ED) condition. BrdU incorporation was also increased about 2.5 fold compared with parental cells in estrogen-free medium. In addition, ESR1 Y537 mutant cells expressed a DNA double-strand break marker, gamma-H2AX protein in ED condition. Apoptosis and senescence were observed in ESR1 Y537S mutant cells in regular medium, however, apoptosis was not shown in ED medium. Chk1 inhibitor, PF477736 sensitized MCF-7 expressing ESR1 Y537S mutation to endocrine treatments such as fulvestrant, tamoxifen and AZD9496.

Conclusion: Combination therapy with cell cycle checkpoint kinase inhibitor may lead better prognosis in ER mutation driven-endocrine resistance in postmenopausal breast cancers.

Citation Format: Kim J-A, Fuqua SAW. Therapeutic strategy for ERα mutation driven-endocrine resistance in ER-positive breast cancers [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 P4-04-08.

Single-stage cell-based cartilage repair in a rabbit model: cell tracking and in vivo chondrogenesis of human umbilical cord blood-derived mesenchymal stem cells and hyaluronic acid hydrogel composite

OBJECTIVE

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have gained popularity as a promising cell source for regenerative medicine, but limited in vivo studies have reported cartilage repair. In addition, the roles of MSCs in cartilage repair are not well-understood. The purpose of this study was to investigate the feasibility of transplanting hUCB-MSCs and hyaluronic acid (HA) hydrogel composite to repair articular cartilage defects in a rabbit model and determine whether the transplanted cells persisted or disappeared from the defect site.

DESIGN

Osteochondral defects were created in the trochlear grooves of the knees. The hUCB-MSCs and HA composite was transplanted into the defect of experimental knees. Control knees were transplanted by HA or left untreated. Animals were sacrificed at 8 and 16 weeks post-transplantation and additionally at 2 and 4 weeks to evaluate the fate of transplanted cells. The repair tissues were evaluated by gross, histological and immunohistochemical analysis.

RESULTS

Transplanting hUCB-MSCs and HA composite resulted in overall superior cartilage repair tissue with better quality than HA alone or no treatment. Cellular architecture and collagen arrangement at 16 weeks were similar to those of surrounding normal articular cartilage tissue. Histological scores also revealed that cartilage repair in experimental knees was better than that in control knees. Immunohistochemical analysis with anti-human nuclear antibody confirmed that the transplanted MSCs disappeared gradually over time.

CONCLUSION

Transplanting hUCB-MSCs and HA composite promote cartilage repair and interactions between hUCB-MSCs and host cells initiated by paracrine action may play an important role in cartilage repair.

Epileptiform abnormalities predict delayed cerebral ischemia in subarachnoid hemorrhage

OBJECTIVE

To identify whether abnormal neural activity, in the form of epileptiform discharges and rhythmic or periodic activity, which we term here ictal-interictal continuum abnormalities (IICAs), are associated with delayed cerebral ischemia (DCI).

METHODS

Retrospective analysis of continuous electroencephalography (cEEG) reports and medical records from 124 patients with moderate to severe grade subarachnoid hemorrhage (SAH). We identified daily occurrence of seizures and IICAs. Using survival analysis methods, we estimated the cumulative probability of IICA onset time for patients with and without delayed cerebral ischemia (DCI).

RESULTS

Our data suggest the presence of IICAs indeed increases the risk of developing DCI, especially when they begin several days after the onset of SAH. We found that all IICA types except generalized rhythmic delta activity occur more commonly in patients who develop DCI. In particular, IICAs that begin later in hospitalization correlate with increased risk of DCI.

CONCLUSIONS

IICAs represent a new marker for identifying early patients at increased risk for DCI. Moreover, IICAs might contribute mechanistically to DCI and therefore represent a new potential target for intervention to prevent secondary cerebral injury following SAH.

SIGNIFICANCE

These findings imply that IICAs may be a novel marker for predicting those at higher risk for DCI development.

Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study

Atrial fibrillation is the most frequent arrhythmia after thoracic surgery and is associated with increased hospital costs, morbidity and mortality. In this study, we aimed to identify potentially modifiable risk factors for postoperative atrial fibrillation following lung resection surgery and to suggest possible measures to reduce risk. We retrospectively reviewed the medical records of 4731 patients who underwent lobectomy or more major lung resection over a 6-year period. Patients who developed atrial fibrillation postoperatively and required treatment were included in the postoperative atrial fibrillation group, while the remaining patients were assigned to the non-postoperative atrial fibrillation group. Risk factors for postoperative atrial fibrillation were analysed by multivariate analysis and propensity score matching. Overall, 12% of patients developed postoperative atrial fibrillation. Potentially modifiable risk factors for postoperative atrial fibrillation were excessive alcohol consumption (odds ratio (OR) = 1.48, 95% CI 1.08-2.02, p = 0.0140), red cell transfusion (2.70(2.13-3.43), p < 0.0001), use of inotropes (1.81(1.42-2.31), p < 0.0001) and open (vs. thoracoscopic) surgery (1.59(1.23-2.05), p < 0.0001). Compared with inotrope use, vasopressor administration was not related to postoperative atrial fibrillation. Use of steroids or thoracic epidural anaesthesia did not reduce the incidence of postoperative atrial fibrillation. We conclude that high alcohol consumption, red cell transfusion, use of inotropes and open surgery are potentially modifiable risk factors for postoperative atrial fibrillation. Pre-operative alcohol consumption needs to be addressed. Avoiding red cell transfusion and performing lung resection via video-assisted thoracoscopic surgery may reduce the incidence of postoperative atrial fibrillation and the administration of vasopressors rather than inotropes is preferred.

Malva verticillata seed extracts upregulate the Wnt pathway in human dermal papilla cells

OBJECTIVE

Mesenchymal-epithelial interactions are important in controlling hair growth and the hair cycle. The β-catenin pathway of dermal papilla cells (DPCs) plays a pivotal role in morphogenesis and normal regeneration of hair follicles. Deletion of β-catenin in the dermal papilla reduces proliferation of the hair follicle progenitor cells that generate the hair shaft and induces an early onset of the catagen phase. In this study, a modulator of the Wnt/β-catenin activity was studied in oriental herb extracts on cultured human DPCs.

METHODS

The effect of Malva verticillata (M. verticillata) seeds on human DPCs was investigated by a Wnt/β-catenin reporter activity assay system (β-catenin-TCF/LEF reporter gene) and cell proliferation analysis. The synthesis of the factors related to hair growth and cycling was measured at both the mRNA and the protein level by semi-quantitative PCR and Western blot analysis, respectively.

RESULTS

An extract from M. verticillata seeds increased Wnt reporter activity in a concentration-dependent manner and also led to increased β-catenin levels in cultured human DPCs. Myristoleic acid, identified as an effective compound of M. verticillata seeds, stimulated the proliferation of DPCs in a dose-dependent manner and increased transcription levels of the downstream targets: IGF-1, KGF, VEGF and HGF. Myristoleic acid also enhanced the phosphorylation of MAPKs (Akt and p38).

CONCLUSION

Overall, the data suggest that this extract of M. verticillata seeds could be a good candidate for treating hair loss by modulating the Wnt/β-catenin pathway in DPCs.

Neural stem cell transplantation at critical period improves learning and memory through restoring synaptic impairment in Alzheimer's disease mouse model

Alzheimer's disease (AD) is characterized by neuronal loss in several regions of the brain. Recent studies have suggested that stem cell transplantation could serve as a potential therapeutic strategy to halt or ameliorate the inexorable disease progression. However, the optimal stage of the disease for stem cell transplantation to have a therapeutic effect has yet to be determined. Here, we demonstrated that transplantation of neural stem cells into 12-month-old Tg2576 brains markedly improved both cognitive impairments and neuropathological features by reducing β-amyloid processing and upregulating clearance of β-amyloid, secretion of anti-inflammatory cytokines, endogenous neurogenesis, as well as synapse formation. In contrast, the stem cell transplantation did not recover cognitive dysfunction and β-amyloid neuropathology in Tg2576 mice aged 15 months when the memory loss is manifest. Overall, this study underscores that stem cell therapy at optimal time frame is crucial to obtain maximal therapeutic effects that can restore functional deficits or stop the progression of AD.

Ecklonia cava promotes hair growth

BACKGROUND

Previous studies have reported the protective effects on skin elasticity of the edible marine seaweed Ecklonia cava, which acts through regulation of both antioxidative and anti-inflammatory responses.

AIM

We evaluated the effect of E. cava and one of its components, dioxinodehydroeckol, on hair-shaft growth in cultured human hair follicles and on hair growth in mice.

METHODS

The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to check cell viability of human dermal papilla cells (DPCs) and outer root sheath (ORS) cells after treatment with E. cava and its metabolite, dioxinodehydroeckol. Hair-shaft growth was measured using the in vitro hair-follicle organ-culture system, in the presence or absence of E. cava and dioxinodehydroeckol. Anagen induction activity was examined by topical application of E. cava to the dorsal skin of C57BL/6 mice. Insulin-like growth factor (IGF)-1 expression was measured by reverse transcriptase PCR and ELISA.

RESULTS

The proliferation activity was found to be highest for the ethyl acetate-soluble fraction of E. cava (EAFE) in DPCs and in ORS cells. Treatment with EAFE resulted in elongation of the hair shaft in cultured human hair follicles, and promoted transition of the hair cycle from the telogen to the anagen phase in the dorsal skin of C57BL/6 mice. In addition, EAFE induced an increase in IGF-1 expression in DPCs. Dioxinodehydroeckol, a component of E. cava, induced elongation of the hair shaft, an increase in proliferation of DPCs and ORS cells, and an increase in expression of IGF-1 in DPCs.

CONCLUSIONS

These results suggest that E. cava containing dioxinodehydroeckol promotes hair growth through stimulation of DPCs and ORS cells.

Abstract P3-04-04: Amplification and overexpression of TLK2 promote genomic instability in invasive breast cancer

The accumulation of numerous chromosomal aberrations is a hallmark characteristic of invasive breast cancer (IBC). It is thus critical to find specific chromosomal aberrations that may drive breast cancer initiation and progression, particularly those that are drivers of the genomic instability. By integrative analysis of genomic data from The Cancer Genome Atlas (TCGA), we have nominated Tousled-Like Kinase 2 (TLK2) as a candidate oncogene target for IBC. Ultra-high resolution copy-number data from TCGA suggest that TLK2 was amplified in approximately 10% of IBC, which are more frequent in luminal B than luminal A tumors. These data also revealed that TLK2-high breast tumors harbor significantly more global copy-number aberrations than the TLK2 low-tumors. TLK2 is a nuclear serine/threonine kinase that serves as a cell cycle checkpoint regulating chromatin assembly, and in response to DNA damage, TLK2 can be inactivated by phosphorylation through the ATM-dependent pathway. We thus postulated that up-regulation of TLK2 may help cancer cells to surpass the cell cycle checkpoint upon DNA damage, which may promote genomic instability in breast cancer cells. To analyze the effect of TLK2 overexpression, we introduced an inducible expression vector containing the TLK2 open-reading frame into the MCF10A benign epithelial cells and the T47D breast cancer cells. As shown by fluorescence activated cell sorting (FACS), ectopic expression of TLK2 in these cells overcame the cell cycle checkpoint in response to the DNA damage induced by gamma irradiation. gamma-H2AX foci formation revealed increased DNA double strand breaks and prolonged DNA repair window after irradiation in the TLK2 overexpressing cells. Interestingly, immunofluorescence localized TLK2 to the nucleus of breast cancer cells, which was markedly enriched in DNA double-strand break foci (or gamma-H2AX foci). To examine the effect of TLK2 knockdown, the MCF7 and MDAMB361 breast cancer cells overexpressing TLK2 were transfected with different TLK2 siRNAs. TLK2 inhibition led to G1/S cell cycle arrest (FACS analysis), profound decrease in cell growth (MTT assay), and enhanced apoptosis (Annexin V assay) in the MCF7 and MDAMB361 breast cancer cells over-expressing TLK2. Together, this study supports the role of TLK2 deregulation in the increased genomic instability of TLK2-high breast cancers, and suggests its potential as an attractive therapeutic target.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-04-04.

A comparison of the BURP and conventional and modified jaw thrust manoeuvres for orotracheal intubation using the Clarus Video System

We evaluated the effects of three airway manipulation manoeuvres: (a) conventional (single-handed chin lift); (b) backward, upward and right-sided pressure (BURP) manoeuvre; and (c) modified jaw thrust manoeuvre (two-handed aided by an assistant) on laryngeal view and intubation time using the Clarus Video System in 215 patients undergoing general anaesthesia with orotracheal intubation. In the first part of this study, the laryngeal view was recorded as a modified Cormack-Lehane grade with each manoeuvre. In the second part, intubation was performed using the assigned airway manipulation. The primary outcome was the time to intubation, and the secondary outcomes were the modified Cormack-Lehane grade, the number of attempts and the overall success rate. There were significant differences in modified Cormack-Lehane grade between the three airway manipulations (p < 0.0001). Post-hoc analysis indicated that the modified jaw thrust improved the laryngeal view compared with the conventional (p < 0.0001) and the BURP manoeuvres (p < 0.0001). The BURP worsened the laryngeal view compared with the conventional manoeuvre (p = 0.0132). The time to intubation in the modified jaw thrust group was shorter than with the conventional manoeuvre (p = 0.0004) and the BURP group (p < 0.0001). We conclude that the modified jaw thrust is the most effective manoeuvre at improving the laryngeal view and shortening intubation time with the Clarus Video System.

The effects of prolonged inspiratory time during one-lung ventilation: a randomised controlled trial

We evaluated the effects of a prolonged inspiratory time on gas exchange in subjects undergoing one-lung ventilation for thoracic surgery. One hundred patients were randomly assigned to Group I:E = 1:2 or Group I:E = 1:1. Arterial blood gas analysis and respiratory mechanics measurements were performed 10 min after anaesthesia induction, 30 and 60 min after initiation of one-lung ventilation, and 15 min after restoration of conventional two-lung ventilation. The mean (SD) ratio of the partial pressure of arterial oxygen to fraction of inspired oxygen after 60 min of one-lung ventilation was significantly lower in Group I:E = 1:2 compared with Group I:E = 1:1 (27.7 (13.2) kPa vs 35.2 (22.1) kPa, respectively, p = 0.043). Mean (SD) physiological dead space-to-tidal volume ratio after 60 min of one-lung ventilation was significantly higher in Group I:E = 1:2 compared with Group I:E = 1:1 (0.46 (0.04) vs 0.43 (0.04), respectively, p = 0.008). Median (IQR [range]) peak inspiratory pressure was higher in Group I:E = 1:2 compared with Group I:E = 1:1 after 60 min of one-lung ventilation (23 (22-25 [18-29]) cmH2O vs 20 (18-21 [16-27]) cmH2O, respectively, p < 0.001) and median (IQR [range]) mean airway pressure was lower in Group I:E = 1:2 compared with Group I:E = 1:1 (10 (8-11 [5-15]) cmH2O vs 11 (10-13 [5-16]) cmH2O, respectively, p < 0.001). We conclude that, compared with an I:E ratio of 1:2, an I:E ratio of 1:1 resulted in a modest improvement in oxygenation and decreased shunt fraction during one-lung ventilation.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor gemigliptin compared with sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone

AIMS

This study was designed to assess the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, gemigliptin versus sitagliptin added to metformin in patients with type 2 diabetes.

METHODS

We conducted a double-blind, randomized, active-controlled trial in 425 Asian patients with inadequately controlled type 2 diabetes being treated with metformin alone. Eligible patients were randomized into three groups: 50 mg gemigliptin qd, 25 mg gemigliptin bid or sitagliptin 100 mg qd added to ongoing metformin treatment for 24 weeks. Haemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance tests were performed at baseline and 24 weeks after starting the treatment regimen.

RESULTS

Twenty-four weeks later, adding gemigliptin (50 mg/day) to ongoing metformin therapy significantly improved glycaemic control. Reduction in HbA1c caused by 50 mg gemigliptin qd (-0.77% ± 0.8) was non-inferior to that caused by 100 mg sitagliptin qd (-0.8% ± 0.85). Proportion of patients achieving HbA1c <7% while taking 25 mg gemigliptin bid (50%) or 50 mg gemigliptin qd (54.07%) was comparable to the results with 100 mg sitagliptin qd (48.87%). There were significant decreases in FPG, postprandial glucose and AUC0-2 h glucose, as well as increases in GLP-1 and β cell sensitivity to glucose (supported by homeostasis model assessment of β-cell function, postprandial 2-h c-peptide and insulinogenic index) in patients receiving gemigliptin treatment with their metformin therapy. There was no increased risk of adverse effects with this dose of gemigliptin compared with sitagliptin 100 mg qd.

CONCLUSIONS

Addition of gemigliptin 50 mg daily to metformin was shown to be efficacious, well tolerated and non-inferior to sitagliptin in patients with type 2 diabetes mellitus.

A multicentre, multinational, randomized, placebo-controlled, double-blind, phase 3 trial to evaluate the efficacy and safety of gemigliptin (LC15-0444) in patients with type 2 diabetes

AIM

This study was designed to assess the efficacy and safety of the dipeptidyl peptidase IV inhibitor gemigliptin (LC15-0444) 50 mg versus placebo in patients with type 2 diabetes.

METHODS

We conducted a 24-week, randomized, double-blind, placebo-controlled phase III trial in 182 patients (74 from Korea and 108 from India) with type 2 diabetes. After an initial 2 weeks of a diet and exercise programme followed by 2 weeks of a single-blind placebo run-in period, eligible patients were randomized to gemigliptin 50 mg or placebo, receiving the assigned treatment for 24 weeks. HbA1c and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance test was performed at baseline and weeks 12 and 24.

RESULTS

At week 24, gemigliptin treatment led to significant reductions in HbA1c measurements compared to placebo (adjust mean after subtracting the placebo effect size: -0.71%, 95% confidence interval: -1.04 to -0.37%). A significantly greater proportion of patients achieved an HbA1c <7% with gemigliptin than with placebo. The placebo-subtracted FPG change from baseline at week 24 was -19.80 mg/dl. The overall incidence rates for adverse events were similar in the gemigliptin and placebo groups.

CONCLUSIONS

This study showed the efficacy and safety of gemigliptin 50 mg administered once daily as a monotherapy for type 2 diabetes patients.

The chromene sargachromanol E inhibits ultraviolet A-induced ageing of skin in human dermal fibroblasts

BACKGROUND

Skin ageing is influenced by environmental factors such as ultraviolet (UV) radiation. The effects of UV radiation on skin functions should be investigated using human in vitro models to understand the mechanisms of skin ageing. Additionally, marine algae provide a valuable source for identifying and extracting biologically active substances.

OBJECTIVES

In this study, sargachromanol E was isolated from a marine brown alga, Sargassum horneri, and its inhibitory effect on skin ageing was investigated using UVA-irradiated dermal fibroblasts.

METHODS

Formation of intracellular reactive oxygen species (ROS), lipid peroxidation and protein oxidation induced by UVA irradiation were investigated in UVA-irradiated human dermal fibroblasts. The levels of matrix metalloproteinases (MMPs) were determined by reverse-transcriptase polymerase chain reaction and Western blot analysis.

RESULTS

Sargachromanol E did not exhibit any significant cytotoxicity or phototoxicity in UVA-exposed dermal fibroblasts. Additionally, sargachromanol E suppressed intracellular formation of ROS, membrane protein oxidation, lipid peroxidation and expression of collagenases such as MMP-1, MMP-2 and MMP-9, all of which are caused by UVA exposure. It was further found that these inhibitions were related to an increase in the expression of the tissue inhibitor of metalloproteinase (TIMP) genes, TIMP1 and TIMP2. Moreover, we have shown that the transcriptional activation of activator protein 1 (AP-1) signalling caused by UVA irradiation was inhibited by treatment with sargachromanol E.

CONCLUSIONS

This study suggests that UVA irradiation modulates MMP expression via the transcriptional activation of AP-1 signalling, whereas treatment with sargachromanol E protected cell damage caused by UVA irradiation.

Abstract PD09-08: The potential role of TLK2 as a therapeutic target in breast cancer

Invasive breast cancer (IBC) is a heterogeneous disease with distinct molecular and histological features as well as diverse biological behaviors. It is thus critical to find specific gene aberrations that can drive breast cancer initiation and progression as potential therapeutic targets. Our lab has established bioinformatics workflows to identify therapeutic oncogene targets. We have nominated Tousled-Like Kinase 2 (TLK2) as a candidate therapeutic target from 44,932 human genes based on integrative copy number data from The Cancer Genome Atlas (TCGA). TLK2 is a nuclear serine/threonine kinase that serves as a cell cycle checkpoint regulating chromosome assembly, and is inactivated by phosphorylation through the ATM dependent manner in the response to the double strand breaks during the S-phase. Interestingly, we observed 12–14% of focal TLK2 gene amplifications and translocations in invasive breast cancers, which are more frequent in luminal B tumors. Chromosomal aberrations may leads the deregulation of TLK2 kinase activity and results in overcoming the cell cycle checkpoint upon DNA damage such as IR or chemotherapeutic drugs treatments in breast cancer, thus destabilizing the cancer genome. Indeed, our preliminary data show that TLK2 knockdown substantially inhibits cell proliferation in breast cancer cells overexpressing TLK2. Further, this response is sustained in their derivative strains resistant to hormone or anti-Her2 therapies, suggesting the potential of TLK2 inhibition to sensitize these therapies as well. Overall, I expect that this study will provide compelling evidence regarding the role of TLK2 in breast cancer tumorigenesis and genomic instability, and establish its potential as a therapeutic target. The possibility of developing specific TLK2 inhibitors can be well demonstrated by the previous success of drugs against other cell cycle checkpoint kinases that are currently under clinical trials. In addition, molecular assays detecting TLK2 derangements may be applied in the clinics to identify patients who might benefit from future TLK2 inhibitor. If TLK2 endows resistance or sensitivity to other therapies, assays detecting TLK2 aberrations may also have important predictive value for personalization of these treatments.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD09-08.

Activation of de novo GSH synthesis pathway in mouse spleen after long term low-dose γ-ray irradiation

Glutathione (GSH) is an important cellular antioxidant and has a critical role in maintaining the balance of cellular redox. In this study, we investigated the GSH biosynthesis genes involved in the elevation of endogenous GSH levels using an irradiation system with an irradiation dose rate of 1.78 mGy/h, which was about 40,000 times less than the dose rates used in other studies. The results showed that GSH levels were significantly increased in the low-dose (0.02 and 0.2 Gy) irradiated group compared to those in the non-irradiated group, but enzymatic antioxidants such as superoxide dismutase and catalase were not induced at any doses tested. The elevation in GSH was accompanied by elevated expression of glutamate-cysteine ligase modifier subunit, but no changes were observed in the expression of glutamate-cysteine ligase catalytic subunit and thioredoxin in de novo GSH synthesis. In the case of genes involved in the GSH regeneration cycle, the expression of glutathione reductase was not changed after irradiation, whereas glutathione peroxidase was only increased in the 0.2 Gy irradiated group. Collectively, our results suggest that the de novo pathway, rather than the regeneration cycle, may be mainly switched on in response to stimulation with long-term low-dose radiation in the spleen.

Effect of radiation therapy on survival in surgically resected retroperitoneal sarcoma: a propensity score-adjusted SEER analysis

BACKGROUND

Currently no prospective randomized trial has measured the efficacy of radiation therapy for resected retroperitoneal sarcomas (RPS). Our objective was to determine the effect of radiation therapy on disease-specific and overall survival between propensity score-matched surgically resected RPS patients using the Surveillance, Epidemiology, and End Results (SEER) database.

PATIENTS AND METHODS

The study population consisted of patients with histologically confirmed RPS who underwent surgical resection between 1988 and 2006. Exclusion criteria included multiple malignancies, distant metastasis, and unknown grade or stage. Cox modeling was used to determine covariate associations with disease-specific survival. Propensity score methods were used to perform survival analysis in patients who received radiation matched with patients who underwent surgery alone.

RESULTS

Prior to matching, there were 762 patients (558 surgery only, 204 surgery with radiation). Factors independently associated with radiation therapy were age (P = 0.037), geographic region (P = 0.041), grade (P = 0.047), stage (P = 0.003), and surgery type (P = 0.01). Cox modeling demonstrated that age, sex, grade, and stage were independently associated with survival. Propensity scoring (309 matched pairs) and survival analysis using Kaplan-Meier methods demonstrated no difference between propensity score-matched patients receiving radiation therapy and those who did not (P = 0.35).

CONCLUSION

At present, SEER patients with surgically resected RPS who received radiation therapy did not demonstrate survival benefit.

Identification and characterization of seed-specific transcription factors regulating anthocyanin biosynthesis in black rice

Black rice is rich in anthocyanin and is expected to have more healthful dietary potential than white rice. We assessed expression of anthocyanin in black rice cultivars using a newly designed 135 K Oryza sativa microarray. A total of 12,673 genes exhibited greater than 2.0-fold up- or down-regulation in comparisons between three rice cultivars and three seed developmental stages. The 137 transcription factor genes found to be associated with production of anthocyanin pigment were classified into 10 groups. In addition, 17 unknown and hypothetical genes were identified from comparisons between the rice cultivars. Finally, 15 out of the 17 candidate genes were verified by RT-PCR analysis. Among the genes, nine were up-regulated and six exhibited down-regulation. These genes likely play either a regulatory role in anthocyanin biosynthesis or are related to anthocyanin metabolism during flavonoid biosynthesis. While these genes require further validation, the results here underline the potential use of the new microarray and provide valuable insight into anthocyanin pigment production in rice.

A case of bilateral ovarian synchronous tumors (left ovarian serous papillary adenocarcinoma and right ovarian malignant mixed Müllerian tumor)

Synchronous bilateral ovarian cancer is extremely rare and there is no established guideline for management. A case of a 58-year-old multiparous woman with bilateral ovarian synchronous malignant tumors is presented. The clinical consideration and treatment of related cases are discussed.

A multicenter, randomized, placebo-controlled, double-blind phase II trial evaluating the optimal dose, efficacy and safety of LC 15-0444 in patients with type 2 diabetes

AIM

The objective of this study was to evaluate the optimal dose, efficacy and safety of a novel dipeptidyl peptidase-4 (DPP-IV) inhibitor, LC15-0444, in Korean subjects with type 2 diabetes mellitus treated by diet and exercise.

METHODS

This study was a double-blind, randomized, multicenter and parallel-group, dose-range finding study. We enrolled 145 patients (91 men and 54 women) with a median age of 53 years and a median body mass index of 25.1 kg/m(2) . The median baseline fasting plasma glucose (FPG) was 8.1 mmol/l, the median HbA1c was 7.9% and the median time since the diagnosis of diabetes was 3 years. After 2 weeks of an exercise/diet programme followed by 2 weeks of a placebo period, the subjects were randomized to one of the four following groups for a 12-week active treatment period: placebo and 50, 100 or 200 mg of LC15-0444.

RESULTS

All three doses of LC15-0444 significantly reduced the HbA1c from baseline compared to the placebo group (-0.06 vs. -0.98, -0.74 and -0.78% in the placebo and 50, 100 and 200 mg groups, respectively), without a significant difference between the doses. Subjects with a higher baseline HbA1c (≥8.5%) had a greater reduction in HbA1c. Insulin secretory function, as assessed using homeostasis model assessment-beta cell, C-peptide and the insulinogenic index, improved significantly with LC15-0444 treatment. Insulin sensitivity, as assessed using homeostasis model assessment-insulin resistance, also improved significantly after 12 weeks of treatment. The 50 and 200 mg groups had significantly reduced total cholesterol and low-density lipoprotein cholesterol levels at 12 weeks compared to the placebo group. No dosage of LC15-0444 affected weight or waist circumference. The incidences of adverse events were similar in all study subjects.

CONCLUSIONS

LC15-0444 monotherapy (50 mg for 12 weeks) improved the HbA1c, FPG level, oral glucose tolerance test results, β-cell function and insulin sensitivity measures, and was well tolerated in Korean subjects with type 2 diabetes.

Superoxide is a potential culprit of caspase-3 dependent endothelial cell death induced by lysophosphatidylcholine

Oxidative stress in the vascular wall has intimately been implicated in the apoptosis of human umbilical vein endothelial cells (HUVECs) by lysophosphatidylcholine (LPC). However, the major type of reactive oxygen species (ROS) in this apoptotic signaling pathway remains to be clarified. In this study, we report that superoxide mediate LPC-induced caspase-3 dependent apoptosis in cultured HUVECs. The stimulation of HUVECs with LPC evoked apoptosis and ROS generation, and inhibited nitric oxide (NO) production in a dose-dependent manner. The classical caspase-3 dependent apoptosis was determined after 16 hours treatment by Western blotting using an antibody against cleaved caspase-3. The caspase-3 activation induced by LPC was prominently inhibited by antioxidants or NO donors and enhanced by NO inhibitors. Especially, LPC-induced caspase-3 activation was inhibited by superoxide dismutase (SOD) and enhanced by ammonium tetrathiomolybdate, SOD inhibitor. Additionally, xanthine/xanthine oxidase mixture increased the caspase-3 activation but catalase failed to reduce this superoxide-induced caspase-3 activation. These findings indicate that the superoxide generation caused by LPC activates the caspase-3 which results in HUVECs death. This study reveals some evidences linking superoxide with caspase-3 activation and provides a new dimension to superoxide-mediated caspase-3 activation in developing the endothelial dysfunction and atherosclerosis.

SP600125 suppresses Cdk1 and induces endoreplication directly from G2 phase, independent of JNK inhibition

Cell cycle controls ensure that DNA replication (S phase) follows mitosis resulting in two precise copies of the genome. A failure of the control mechanisms can result in multiple rounds of DNA replication without cell division. In endoreplication, cells with replicated genomes bypass mitosis, then replicate their DNA again, resulting in polyploidy. Endoreplication from G2 phase lacks all hallmarks of mitosis. Using synchronized cells, we show that the c-Jun N-terminal kinase (JNK) inhibitor, SP600125, prevents the entry of cells into mitosis and leads to endoreplication of DNA from G2 phase. We show that cells proceed from G2 phase to replicate their DNA in the absence of mitosis. This effect of SP600125 is independent of its suppression of JNK activity. Instead, the inhibitory effect of SP600125 on mitotic entry predominantly occurs upstream of Aurora A kinase and Polo-like kinase 1, resulting in a failure to remove the inhibitory phosphorylation of Cdk1. Importantly, our results directly show that the inhibition of Cdk1 activity and the persistence of Cdk2 activity in G2 cells induces endoreplication without mitosis. Furthermore, endoreplication from G2 phase is independent of p53 control.

Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters

BACKGROUND

In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time.

METHODS

Thirty-three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre-oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time.

RESULTS

The desaturation response time of SpO(2) to 95% after apnea was 82.0 s (interquartile range: 67.0-98.5 s) vs. 94.0 s (interquartile range: 84.0-106.5 s) (P<0.001) and SpO(2) to 90% was 94.0 s (interquartile range: 75.5-109.5 s) vs. 100.0 s (interquartile range: 84.5-114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO(2) was 23.2+/-5.6 vs. 28.9+/-7.6 s (P<0.001) in the reflectance and transmission oximeters, respectively.

CONCLUSION

In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter.

Does propofol and alfentanil-induced sedation cause periodic apnoea in chronic renal failure patients?

AIMS

There is evidence suggesting that the respiratory response to sedation is different in patients with sleep apnoea, which is common in patients with chronic renal failure (CRF). This study examined the respiratory response of sedation with propofol and alfentanil, whose pharmacokinetics are not affected by the renal function, in CRF patients.

METHODS

Chronic renal failure patients who underwent arteriovenous-fistular surgery (CRF group) and patients who underwent chemoport insertion (control group) were enrolled in this study. Sedation was induced by infusing propofol 1.5 micro/ml and alfentanil 0.2 micro/kg/min continuously in both groups. In the desaturation study, the respiratory rate and peripheral oxygen saturation in room air were checked. In the apnoea-hypopnoea study, the patient's sedation (Observer's Assessment of Alertness/Sedation) score, apnoea-hypopnoea index (AHI) was recorded using a portable ventilation effort recorder (microMesam) while applying 5 l/min of oxygen through a facial mask.

RESULTS

The desaturation event was more common (21.5/h vs. 2/h, p = 0.001) in the CRF patients. Apnoea and hypopnoea (AHI: 13.0 vs. 1.6, p = 0.012, per cent of patients with an AHI > 5: 53.3% vs. 7.1%, p = 0.014) occurred more frequently in the CRF patients but the sedation score was not different.

CONCLUSION

Chronic renal failure patients have a higher risk of developing apnoea and hypopnoea during sedation, which highlights the need for careful monitoring and management in these patients.

Diagnosis of breast cancer at dynamic MRI in patients with breast augmentation by paraffin or silicone injection

AIM

To determine the diagnostic performance of dynamic magnetic resonance imaging (MRI) for breast cancer in breasts augmented with liquid paraffin or silicone injection.

MATERIALS AND METHODS

Among 62 patients with breast augmentation by liquid paraffin or silicone injection who had undergone dynamic breast MRI at our institution, 27 women, who had pathological diagnosis or at least 1-year MRI follow-up, were included in this retrospective study and their MRI images were reviewed. For enhancing lesions on MRI, the morphological features, enhancement kinetics, and BI-RADS assessment category were analysed. The lesion characteristics at MRI were correlated with the final diagnosis based on the histopathological result or at least 1-year MRI follow-up.

RESULTS

Of the 27 patients, 17 enhancing lesions in 13 patients were found on MRI. All six lesions that were confirmed as malignancy showed suspicious morphological findings and type 2 or 3 enhancement kinetics, assigned to BI-RADS category 4 or 5. Of the remaining 11 benign lesions, 10 showed benign-favouring morphological findings, and all showed type 1 enhancement kinetics, assigned to BI-RADS category 2 or 4.

CONCLUSION

In patients with breasts injected with foreign material, MRI was used to successfully diagnose malignant breast lesions and could be the diagnostic method of choice. Analysis of the morphological and kinetic features at MRI in conjunction with clinical findings is essential.

Stimulation of large-conductance Ca2+-activated K+ channels by the Na+/Ca2+ exchanger inhibitor dichlorobenzamil in cultured human umbilical vein endothelial cells and mouse aortic smooth muscle cells

We investigated the effects of the selective inhibitor of Na(+)/Ca(2+) exchanger (NCX), 2',4'- and 3',4'-dichlorobenzamil (DCB), on large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in cultured human umbilical vein endothelial cells (HUVECs) and fresh isolated mouse aortic smooth muscle cells (MASMCs) using the patch clamp techniques. Both kinds of DCB reversibly activated BK(Ca) currents in whole-cell clamped HUVECs or MASMCs. The EC(50) of 2',4'-DCB for BK(Ca) current activation in HUVECs was 2.64 +/- 0.10 muM. In inside-out and outside-out patches, 2',4'-DCB remarkably increased BK(Ca) channels activity. 2',4'-DCB increased open frequency, but had no significant effect on mean open time. In inside-out patches, 2',4'-DCB shifted the relationship curve between [Ca(2+)](i) and open probability (NP(o)) to the left; the [Ca(2+)](i) required to evoke half-maximal activation changed from 1087.45 +/- 142.91 nM to 500.24 +/- 66.83 nM by 10 muM 2',4'-DCB. In addition, 2',4'-DCB shifted the relationship curve between membrane potential and NP(o) to the left; the membrane potential to evoke half-maximal activation changed from 81.1 +/- 2.4 to 64.7 +/- 3.1 mV by 10 muM 2',4'-DCB. 3',4'-DCB also increased BK(Ca) channels activity. There was no significant difference in the effect of DCB on BK(Ca) channels between both excised patches. These results suggested that 2',4'- and 3',4'-DCB activate BK(Ca) channels activity in HUVECs and MASMCs by increasing the sensitivity of BK(Ca) channels to cytosolic free Ca(2+) and membrane potential. Our report would provide a consideration if they are used as NCX blocker in vascular endothelial cells or smooth muscle cells.

Association of abdominal fat distribution and cardiometabolic risk factors among obese Korean adolescents

The association between abdominal fat distribution and cardiometabolic risk factors using direct measures of abdominal fat in adolescents has not been extensively researched. This study was designed to investigate the association between visceral and subcutaneous fat and cardiometabolic risk factors, in obese Korean adolescents. The study enrolled 175 adolescents (72 boys, 103 girls), from ages nine to 19 years, who were referred to the Obesity Clinic of Asan Medical Center. Body mass index (BMI) and waist circumference (WC) were measured for each study participant. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were calculated by computed tomography. Blood pressure, fasting plasma glucose, total cholesterol, triglycerides, HDL cholesterol, insulin and homeostasis model assessment (HOMA) score were measured. Systolic blood pressure, HDL cholesterol, fasting insulin and the HOMA score were significantly correlated with BMI, WC, VAT and SAT. In addition, VAT was significantly correlated with diastolic blood pressure and triglyceride levels. On multiple regression analysis, VAT was independently correlated with blood pressure, triglycerides, HDL cholesterol, fasting insulin and the HOMA score, while SAT was independently correlated with systolic blood pressure, fasting insulin and the HOMA score. This study determined that cardiovascular risk factors are closely associated with VAT, while insulin resistance is closely associated with both VAT and SAT among obese Korean adolescents.

The effect of beta-cyclodextrin complexation on the bioavailability and hepatotoxicity of clotrimazole

Clotrimazole, a poorly water-soluble antimycotic agent, is a promising therapeutic agent for various diseases including cancer and sickle cell anemia. The oral bioavailability and hepatic toxicity of clotrimazole were compared with its beta-cyclodextrin inclusion form which was prepared by the spray-drying method. The inclusion complex gave significantly higher initial plasma concentrations, Cmax and AUC than did clotrimazole alone, indicating that the drug from the inclusion compound could be more easily absorbed in rats. Furthermore, mice treated with the inclusion compound showed significantly higher GOT/GPT values compared to clotrimazole alone. The inclusion compound also induced hypertrophy of hepatic cells by fat accumulation and disappearance of hepatic sinusoids, indications of pathological changes of liver, suggesting that the inclusion compound could induce more severe tissue damage in the liver than clotrimazole alone. Thus, hepatotoxicity of clotrimazole seems to be correlated with the enhanced oral bioavailability by inclusion complexation. Our results suggest that, in the development of a novel oral product, appearance or enhancement of hepatic toxicity must be considered along with oral bioavailability.

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats

The effects of chronic neuromuscular inactivity on the phenotype and size of muscle fibres in a fast ankle extensor (medial gastrocnemius, MG) and a fast ankle flexor (tibialis anterior, TA) muscle of the rat hindlimb were determined. Inactivity was produced by spinal cord isolation (SI), i.e. complete spinal cord transections at a mid-thoracic and high sacral level and bilateral deafferentation between the transection sites. After 90 days of SI, the MG and TA muscle weights were 53 and 45% lower than in age-matched controls. Overall mean fibre sizes in the deep (close to the bone) and superficial (away from the bone) regions were approximately 60 and 65% smaller in the MG and approximately 40 and 50% smaller in the TA of SI than control rats, respectively. The myosin heavy chain (MHC) composition shifted towards the faster isoforms after SI: the MG showed an increase in both types IIx (20%) and IIb (23%), whereas the TA showed a marked increase in type IIx (94%) and a decrease in type IIb (18%) MHC. Both muscles in SI rats showed no type IIa and only one MG muscle had approximately 5% type I MHC. These results show that prolonged inactivity has a stronger effect on a fast extensor compared with a fast flexor in the rat hindlimb. The larger decrease in mass and fibre size in the MG than the TA most probably reflects the larger impact of chronic inactivity on the normally more highly recruited extensor than flexor muscle. The primary shift to type IIb MHC in the MG and type IIx MHC in the TA indicate a different default mode for an inactive extensor vs. flexor muscle, and may reflect differing activity-independent neural influences, i.e. neurotrophic factors, on muscle fibre phenotype in extensors vs. flexors.

Evaluation of the Cobra perilaryngeal airway (CPLA) as an airway conduit

BACKGROUND AND OBJECTIVE

The effectiveness of the Cobra perilaryngeal airway as a routine airway device and as a conduit for tracheal intubation has not been prospectively studied to date. This study aimed to evaluate the Cobra perilaryngeal airway for its potential role in an emergency airway rescue, by analysing its use as a bridge to blind or fibre-optic-guided intubation.

METHODS

In 49 patients, the procedure was carried out as follows: fibre-optic view through the Cobra perilaryngeal airway was assessed after the insertion of the Cobra perilaryngeal airway, then blind intubation through the Cobra perilaryngeal airway was attempted. After evaluating the success of blind intubation, fibre-optic-guided intubation was performed through the Cobra perilaryngeal airway. The endotracheal tube was removed after evaluating the success of fibre-optic-guided intubation, and then conventional laryngoscopy was carried out to evaluate the Cormack & Lehane grade and airway trauma.

RESULTS

In all, 95.9% (47/49) of patients had adequate ventilation using the Cobra perilaryngeal airway; the success rates for the blind and fibre-optic-guided intubation were 36.2% and 83.0%, respectively. The patients were divided into two groups according to the fibre-optic view. Group 1 included patients with an obstructed view by an anterior grill of the Cobra perilaryngeal airway head, and a view of the anterior epiglottis (downfolded epiglottis) with or without a visible larynx (16/47, 34.0%). Group 2 included the remaining patients (31/47, 66.0%). The success rates of the blind and fibre-optic intubations were different between the two groups (blind intubation: 12.5% vs. 48.4%, fibre-optic intubation: 62.5% vs. 93.6%, P 0.05). 42.6% of patients had blood staining after removing the device and complications such as trauma and oedema were confirmed under direct laryngoscopy.

CONCLUSION

This study suggests that the Cobra perilaryngeal airway could be a useful airway device as a vehicle for fibre-optic-guided intubation; however, it needs caution against airway trauma.

Effects of sevoflurane on the cAMP-induced short-circuit current in mouse tracheal epithelium and recombinant Cl- (CFTR) and K+ (KCNQ1) channels

BACKGROUND

An optimal level of airway surface liquid is essential for mucociliary clearance in lungs. The cAMP-activated cystic fibrosis transmembrane conductance regulator (CFTR) and KCNQ1 channels in tracheal epithelium play key roles in luminal and basolateral membranes, respectively. The aim of this study was to examine the effects of sevoflurane on cAMP-induced chloride secretion by the mouse tracheal epithelium and the modulation of recombinant CFTR and KCNQ1 channels.

METHODS

The equivalent short-circuit current (Isc) of the mouse tracheal epithelium was measured using a flow-type Ussing chamber technique. Inhibition of Na+ absorption was achieved through the luminal application of amiloride. cAMP-dependent Cl- secretion was evoked by forskolin and isobutylmethylxanthine (Fsk/IBMX) applied to the basolateral side. The effect of sevoflurane on CFTR and KCNQ1 channels was assessed using a whole-cell patch clamp in human embryonic kidney 293T cells expressing CFTR and KCNQ1 channels.

RESULTS

Fsk/IBMX induced a sustained Isc that was suppressed by the application of sevoflurane [decreased by 49 (4.5)% at 190 microM]. The Fsk/IBMX-induced Isc was also blocked by basolateral application of chromanol 293B, a blocker of the KCNQ1 K+ channel. In KCNQ1-expressing cells, sevoflurane 190 microM reduced the outward currents to 59 (4.9)% at 80 mV. The CFTR current was not affected by sevoflurane (approximately 360 microM).

CONCLUSIONS

These results suggest that the inhibition of KCNQ1 underlies sevoflurane-induced decrease in airway secretion.

Influence of the baricity of a local anaesthetic agent on sedation with propofol during spinal anaesthesia

BACKGROUND

This study examined the effect of different levels of spinal anaesthesia, induced by solutions of different baricity but containing the same amount of local anaesthetic agent, on the requirement for sedation with propofol.

METHODS

Thirty-six patients undergoing varicose vein surgery under spinal anaesthesia were randomly allocated to receive tetracaine 15 mg in 3 ml of either glucose 5% (hyperbaric) or CSF (isobaric). I.V. propofol was started 5 min after the intrathecal injection and was titrated to maintain a bispectral index (BIS) score of 65-75. The propofol requirements to maintain this range in the two groups were compared every 5 min.

RESULTS

The propofol requirement was always lower in the hyperbaric group, with the differences becoming statistically significant 20 min after the intrathecal injection. Total consumption of propofol over the 55 min of the study was also less in the hyperbaric group.

CONCLUSION

The known difference in level of spinal anaesthetic block induced by solutions of different baricity, but the same dose of local anaesthetic, was associated with different requirements for propofol sedation as determined by BIS assessment.

Expression and role of interleukin-6 in distraction osteogenesis

Distraction osteogenesis is a special form of bone healing in which well-controlled distraction stresses and consequent tensile strains within callus tissue induce very efficient new bone formation. Proinflammatory cytokines are involved during the early phase of fracture healing and callus remodeling. Temporal expression patterns of proinflammatory cytokines were assessed in Sprague-Dawley rat tibial models of distraction osteogenesis and acute lengthening, and only interleukin-6 (IL-6) was found to be specifically induced during the distraction phase. IL-6 immunoreactivity was detected not only in hemopoietic cells and osteoblasts but also in the spindle-shaped cells of the fibrous interzone, where most of the tensile strains are concentrated. In vitro study revealed that IL-6 did not affect the proliferation of C3H10T1/2 cells, mouse bone marrow stromal cells (MSCs), or MC3T3-E1 cells; but its blocking antibody reduced the proliferation of C3H10T1/2 cells and MSCs. The mRNA expression of COL1A1 and osteopontin were not changed by IL-6 or its blocking antibody, but the alkaline phosphatase activities of MC3T3-E1 cells were increased by IL-6 and decreased by its blocking antibody. These findings indicate that IL-6 is a proinflammatory cytokine that responds to tensile strain during distraction osteogenesis. IL-6 negatively affects the proliferation of primitive mesenchymal cells, whereas the differentiation of more mature osteoblastic lineage cells is enhanced by IL-6 in vitro. IL-6 appears to be one of the cytokines involved in the complex network of signal cascades evoked during distraction osteogenesis and may differentially affect immature and mature osteoblastic lineage cells.

The prevalence and risk factors associated with isolated untreated systolic hypertension in Korea: the Korean National Health and Nutrition Survey 2001

Although isolated systolic hypertension (ISH) increases the risk of coronary heart disease and stroke, more than any other hypertension subtype, the prevalence and risk factors associated with ISH in the Korean population are not known. The 2001 Korean National Health and Nutrition Survey was a cross-sectional and nationally representative survey conducted in 2001. The prevalence of ISH by age and body mass index (BMI) was examined in 6601 Korean adults over 20 years of age. After adjusting for age, 4.32+/-0.32% of Korean adults had ISH, 5.28+/-0.37% had isolated diastolic hypertension and 5.82+/-0.36% had systolic/diastolic hypertension. The overall prevalence of ISH was found to increase directly with advancing age and increasing BMI. Although the ISH was found to be more common in men overall (4.81+/-0.50% in men, 4.12+/-0.37% in women), it was more common in women over 70 years of age. Independent variables associated with risk for ISH included advanced age, BMI, triglyceride (TG) levels, monthly income and alcohol intake. However, gender, fasting blood glucose, total cholesterol and high-density lipoprotein cholesterol levels, residential area, education level and smoking were found not to be significantly associated with ISH risk. The findings of the present study demonstrate that the prevalence of untreated ISH in Korea was lower than in Western countries. Age, BMI, TG levels, monthly income and alcohol intake were associated with ISH.

Characteristics of cutaneous cytomegalovirus infection in non-acquired immune deficiency syndrome, immunocompromised patients

BACKGROUND

Although cytomegalovirus (CMV) disease is a severe complication among immunocompromised patients, its cutaneous features have not been frequently reported. As herpes simple virus (HSV) infection commonly develops in CMV skin lesions, a study is needed on the pathogenetic role of CMV in cutaneous lesion formation.

OBJECTIVES

The purpose of this study is to characterize the clinical and histopathological features of cutaneous CMV infection and to determine whether CMV plays a true pathogenetic role in cutaneous lesions, or if it is just an innocent bystander during HSV infection among non-AIDS (acquired immune deficiency syndrome), immunocompromised patients.

PATIENTS AND METHODS

A total of nine human immunodeficiency virus-negative patients diagnosed with cutaneous CMV infection from July 1999 to February 2005 at Samsung Medical Center were analysed in terms of their clinical and histopathological characteristics. In addition, we examined for the co-presence of HSV by performing immunohistochemical analysis and polymerase chain reaction.

RESULTS

All the patients were immunocompromised; five had haematological diseases and four were organ transplant recipients. The clinical and histopathological features were similar to those of previous studies of patients with AIDS. Multiple anogenital ulcerations were the most frequent cutaneous presentation (66.7%). Most cytopathic changes were found in the dermis, particularly within the vascular endothelial cells (77.8%) and macrophages (66.7%). However, the association of CMV with concurrent HSV infection was even lower than that seen in patients with AIDS. Only one patient revealed a co-existing cutaneous HSV infection.

CONCLUSIONS

In non-AIDS individuals, the cutaneous lesions from CMV infection showed similar clinical and histopathological features to those of patients with AIDS. However, skin lesions may not be highly associated with HSV, and CMV does seem to contribute to lesion development as a cutaneous manifestation among the CMV infected, non-AIDS, immunocompromised patients.

How tonicity regulates genes: story of TonEBP transcriptional activator

TonEBP stimulates genes whose products drive cellular accumulation of organic osmolytes and HSP70, which protect cells from the deleterious effects of hypertonicity and urea, respectively. Mice deficient in the TonEBP gene display severe atrophy of the renal medulla because cells failed to adapt to the hyperosmolality. Emerging data suggest that TonEBP plays a key role in the urinary concentrating mechanism by stimulating the UT-A urea transporters and possibly AQP2 water channel. Thus, TonEBP is an essential regulator in the urinary concentrating mechanism. Studies on structural basis of TonEBP function have revealed the structure of the DNA binding domain, and defined the transactivation domains. Molecular mechanisms underlying the nucleocytoplasmic trafficking, transactivation, and phosphorylation in response to changes in tonicity need to be understood in molecular detail. Such knowledge is needed for the identification of the sensor that detects changes in ambient tonicity and signals to TonEBP.

Activation of NF-κB by HDAC inhibitor apicidin through Sp1-dependent de novo protein synthesis: its implication for resistance to apoptosis

Histone deacetylase (HDAC) inhibitors are promising anti-cancer drugs, but these exert differential responses depending on the cell types. Here, we demonstrate a new mechanism for activation of nuclear factor-kappaB (NF-kappaB) by HDAC inhibitor apicidin and the role of NF-kappaB signaling pathway for mediating differential cellular responses, especially, apoptosis. Treatment of HeLa cells with apicidin increases transcriptional activity of NF-kappaB and its target gene IL-8 and cIAP-1 induction, which involves the activation of IKK-IkappaBalpha signaling pathway through Sp1-dependent de novo protein synthesis. In parallel, apicidin treatment leads to histone hyperacetylation in the IL-8 promoter region independent of NF-kappaB signaling pathway, which is not sufficient for full transcription of IL-8 gene. This NF-kappaB activation contributes to resistance of HeLa cells to apoptotic potential of apicidin. Collectively, our results suggest that activation of NF-kappaB signaling cascade functions as a critical modulator to determine cell fate on apoptosis in response to HDAC inhibitors.

Combined low-dose spinal-epidural anesthesia versus single-shot spinal anesthesia for elective cesarean delivery

Combined spinal-epidural anesthesia balancing low-dose intrathecal bupivacaine/fentanyl and low-dose epidural bupivacaine may be more useful than single-shot spinal anesthesia for cesarean delivery in reducing incidences of adverse effects such as hypotension and nausea and in shortening motor recovery. Combined spinal-epidural anesthesia (n=50) or spinal anesthesia (n=50) was randomly performed in 100 parturients. Intrathecal bupivacaine 6 mg added by fentanyl 20 mug followed after 5 min by 10 mL of 0.25% epidural bupivacaine were used for combined spinal-epidural and intrathecal bupivacaine 9 mg with fentanyl 20 mug for spinal anesthesia. The initial sensory block level was higher in the spinal group (P<0.001), although the maximum levels were the same (T3). Complete surgical anesthesia was achieved and no patient complained of intraoperative pain in either group. Patients in the spinal group had denser motor block in the extremities and a higher incidence of hypotension (P<0.05) and nausea and vomiting (P<0.05). Motor recovery was faster in the combined spinal-epidural group (P<0.001). We concluded that combined spinal-epidural anesthesia using low-dose local anesthetic-opioid spinal anesthesia and routine epidural supplementation before surgery had some potential advantages over single-shot spinal anesthesia in the lower incidences of adverse effects and quicker recovery.