Role of Passive Diffusion, Transporters, and Membrane Trafficking-Mediated Processes in Cellular Drug Transport

Intracellular drug accumulation is thought to be dictated by two major processes, passive diffusion through the lipid membrane or membrane transporters. The relative role played by these distinct processes remains actively debated. Moreover, the role of membrane-trafficking in drug transport remains underappreciated and unexplored. Here we discuss the distinct processes involved in cellular drug distribution and propose that better experimental models are required to elucidate the differential contributions of various processes in intracellular drug accumulation.

Pilot study on the correlation between skin auto-fluorescence and serum antioxidant enzyme: skin auto-fluorescence is negatively associated with levels of malondialdehyde

BACKGROUND/PURPOSE

Various methods have been used to objectively record skin changes. However, estimating the intrinsic and extrinsic aging of skin remains a challenge. Our objective was to study intrinsic skin aging with respect to patient age and extrinsic photo-aging of human dorsal (photo-exposed) and volar (photo-protected) forearm in vivo through skin auto-fluorescence (AF). We also examined the correlations between serum antioxidant enzyme, malondialdehyde(MDA), and skin AF.

METHODS

37 healthy volunteers were enrolled. We measured skin AF and its heterogeneity on the dorsal and volar forearms. We also examined serum concentration of catalase, superoxide dismutase, vitamin E, and MDA levels in every participant.

RESULTS

In photo-protected areas, skin AF intensity in the 40 years or older group was significantly higher compared to the group less than 40 years-old. On the other hand, heterogeneity value was significantly higher in the less than 40 years-old group in photo-protected area. With respect to serum antioxidant enzyme and MDA level, only MDA level showed a negative correlation with skin AF intensity in photo-exposed area.

CONCLUSION

We determined that skin AF intensity of the photo-protected area reflects intrinsic skin aging. In addition, degree of photo-aging could be indirectly inferred by skin AF of photo-exposed area and serum MDA level.

Cardiac Arrest due to a Vagal Reflex Potentiated by Thoracic Epidural Analgesia

Reflex bradycardia and cardiac arrest may be the result of a vagal reflex, which can occur during a variety of surgical procedures. We report a patient who developed cardiac arrest as a result of a vagal reflex that was potentiated by thoracic epidural analgesia during general anaesthesia. A 53-year-old man was scheduled for subtotal gastrectomy because of an early gastric adenocarcinoma. After an epidural catheter had been inserted, general anaesthesia was induced. During surgery, an abdominal self-retaining retractor was set up but bradycardia and cardiac arrest developed. The patient returned to a normal sinus rhythm after successful resuscitation. We conclude that bradycardia as a result of a vagal reflex is mediated by potent abdominal wall traction and is potentiated by epidural analgesia. Early diagnosis and proper treatment can allow a full recovery, even in high-risk patients.

Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3}  eV^{2}.

Reliability of classification of ring and little finger carpometacarpal joint fracture subluxations: a comparison between two-dimensional computed tomography and three-dimensional computed tomography classifications

The aims of this study were to develop a classification for ring and little finger carpometacarpal joint fracture subluxations based on three-dimensional computed tomography images and evaluate the inter- and intraobserver reliability of the three-dimensional computed tomography classification. A retrospective review was performed of 30 cases of ring and little finger carpometacarpal joint fracture subluxations from 2005 to 2013. We classified ring and little finger carpometacarpal joint fracture subluxations into three types based on three-dimensional computed tomography images. An orthopaedic surgeon with 2 years of experience, a consultant hand surgeon with 8 years of experience, and a consultant radiologist with 9 years of experience, who were completely blind to the treatment algorithm, evaluated 30 cases twice at a 2-week interval using our new classification based on three-dimensional computed tomography images and the other classification based on two-dimensional computed tomography images. Our three-dimensional computed tomography classification showed almost perfect interobserver and intraobserver reliability and resulted in a better level of agreement than two-dimensional computed tomography classification.

Abstract P1-15-04: Irriversible chemotherapy-induced alopecia in breast cancer patient

Introduction

Patients with breast cancer who received chemotherapy have distressing side effects such as mucositis, alopecia, gastritis, and BM suppression. Chemotherapy-induced alopecia(CIA) is one of considerable psychological events in self-esteem in patients with breast cancer, but the possibility of irreversible alopecia is often overlooked by physician.

We investigated clinical characteristics of CIA and prevalence of irreversible severe hair loss in patient with breast cancer who received chemotherapy.

Methods

We conducted a survey to collect demographic information about CIA with 150 breast cancer patients who had passed at least 6 months since their last day of chemotherapy from February 2015 to May 2015 in Yonsei Cancer Center. We obtained clinical information as age, elapsed time from end of chemotherapy, chemotherapy regimen, and other adjuvant therapy using their electrical medical records. We compared irreversible CIA characters between anthracycline and cyclophosphamide (AC) and taxane based regimen groups. The severe alopecia was defined as the hair density loss over 50% compared to the hair density before chemotherapy.

Results

The mean age at chemotherapy was 48 years old (±17.3) and the mean elapsed time after chemotherapy was 37 months (±9.5) in total patients.

Remnant alopecia was reported in 71 patients (47.3%). Wig or hat were used in 39 patients (26.0%).

The mean satisfaction score with a five-point scale was 4 in patients without alopecia or hair character change and 2.2 in patients with irreversible alopecia (p<0.001). The severe irreversible hair loss was complained by the 12 (8.2%) patients.

AC and taxane based chemotherapy were carried out in 65 and 85 patients, respectively. In AC group, remnant alopecia was shown in 18 patients (27.7%), and more than a half of patients in taxane group, 53 patients (62.4%), showed remnant alopecia (p<0.001). While only five patients (7.8%) in AC group suffered for severe hair loss, 26 patients (31.3%) in taxane group were affected by severe hair loss (p=0.001). The mean satisfaction level of hair status in patients in taxane group was 2.5 as compared to 3.6 in those in AC group (p<0.001).

Conclusion

Contrary to general expectation, About a half of breast cancer patients who received chemotherapy complained of irreversible hair loss even though at least 6 months has elapsed since the end of chemotherpy. In particular, patients with taxane based chemotherapy had more irreversible and severe alopecia than those with AC chemotherapy.

Citation Format: Kim S, Park HS, Kim JY, Nam S, Kim GM, Sohn JH, Kim SI. Irriversible chemotherapy-induced alopecia in breast cancer patient. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-15-04.

Identifying the potential long-term survivors among breast cancer patients with distant metastasis

BACKGROUND

We aimed to develop a prediction model to identify long-term survivors after developing distant metastasis from breast cancer.

PATIENTS AND METHODS

From the institution's database, we collected data of 547 patients who developed distant metastasis during their follow-ups. We developed a model that predicts the post-metastasis overall survival (PMOS) based on the clinicopathologic factors of the primary tumors and the characteristics of the distant metastasis. For validation, the survival data of 254 patients from four independent institutions were used.

RESULTS

The median duration of the PMOS was 31.0 months. The characteristics of the initial primary tumor, such as tumor stage, hormone receptor status, and Ki-67 expression level, and the characteristics of the distant metastasis presentation including the duration of disease-free interval, the site of metastasis, and the presence of metastasis-related symptoms were independent prognostic factors determining the PMOS. The association between tumor stage and the PMOS was only seen in tumors with early relapses. The PMOS score, which was developed based on the above six factors, successfully identified patients with superior survival after metastasis. The median PMOS for patients with a PMOS score of <2 and for patients with a PMOS score of >5 were 71.0 and 12 months, respectively. The clinical significance of the PMOS score was further validated using independent multicenter datasets.

CONCLUSIONS

We have developed a novel prediction model that can classify breast cancer patients with distant metastasis according to their survival after metastasis. Our model can be a valuable tool to identify long-term survivors who can be potential candidates for more intensive multidisciplinary approaches. Furthermore, our model can provide a more reliable survival information for both physicians and patients during their informed decision-making process.

Development of a highly immunogenic Newcastle disease virus chicken vaccine strain of duck origin

Newcastle disease virus (NDV) strain NDRL0901 was developed as a live vaccine candidate for control of Newcastle disease. NDV isolate KR/duck/13/07 (DK1307) of duck origin was used as the selected vaccine strain. DK1307 was passaged 6 times in chickens. Then a single clone from the chicken-adapted virus (DK1307C) was finally selected, and the vaccine strain was named NDRL0901. DK1307C and the clone NDRL0901 viruses showed enhanced immunogenicity compared to the DK1307 virus. Principal component analysis based on fusion and hemagglutinin-neuraminidase genes revealed the codon usage pattern in the dataset is distinct separating duck viral sequences and avian sequences, and passage of the duck origin virus into the chicken host causes deviation in the codon usage pattern. The NDRL0901 virus was avirulent and did not acquire viral virulence even after 7 back passages in chickens. When day-old chicks were vaccinated with the NDRL0901 virus via spray, eye drops, and drinking water, the vaccinated birds showed no clinical signs and had significant protection efficacy (>80%) against very virulent NDV (Kr005 strain) infection regardless of the administration route employed. The results indicate that the NDRL0901 strain is safe in chickens and can offer protective immunity.

Inhibition of breast cancer invasion by TIS21/BTG2/Pc3-Akt1-Sp1-Nox4 pathway targeting actin nucleators, mDia genes

The mammalian homolog of Drosophila diaphanous (mDia), actin nucleator, has been known to participate in the process of invasion and metastasis of cancer cells via regulating a number of actin-related biological processes. We have previously reported that tumor suppressor TIS21(/BTG2/Pc3) (TIS21) inhibits invadopodia formation by downregulating reactive oxygen species (ROS) in MDA-MB-231 cells. We herein report that TIS21(/BTG2/Pc3) downregulates diaphanous-related formin (DRF) expression via reducing NADPH oxidase 4 (Nox4)-derived ROS generation by Akt1 activation and subsequently impairs invasion activity of the highly invasive breast cancer cells. Knockdown of Akt1 by RNA interference recovered the TIS21(/BTG2/Pc3)-inhibited F-actin remodeling and ROS generation by recovering Nox4 expression. Furthermore, Sp1-mediated Nox4 transcription was downregulated by TIS21(/BTG2/Pc3)-Akt1 signals, leading to the inhibition of cancer cell invasion via F-actin remodeling by mDia genes. To our best knowledge, this is the first study to show that TIS21(/BTG2/Pc3)-Akt1 inhibited Sp1-Nox4-ROS cascade, subsequently reducing invasion activity via inhibition of mDia family genes.

Birthplace and esophageal cancer incidence patterns among Asian-Americans

The incidence of esophageal adenocarcinoma in the United States has risen rapidly over the last 30 years, whereas the incidence of esophageal squamous cell carcinoma has fallen dramatically. In contrast, parts of Asia have extremely high rates of squamous cell carcinoma, but virtually no adenocarcinoma. Within the United States, Asian-Americans as a whole, have low rates of esophageal adenocarcinoma and higher rates of squamous cell carcinoma. It is unclear what the patterns are for those Asians born in the United States. The relative influence of ethnicity and environment on the incidence of esophageal cancer in this population is unknown. We identified all cases of esophageal adenocarcinoma and squamous cell carcinoma from the California Cancer Registry 1988-2004, including 955 cases among 6 different Asian ethnicities. Time trends were examined using Joinpoint software to calculate the annual percentage changes in regression models. Rates of esophageal squamous cell carcinoma varied substantially among different Asian ethnic groups, but squamous cell carcinoma was much more common than adenocarcinoma in both foreign-born and US-born Asian-Americans. Rates of squamous cell carcinoma were slightly higher among US-born Asian men (4.0 per 100,000) compared with foreign-born Asian men (3.2 per 100,000) and White men (2.2 per 100,000), P = 0.03. Rates of adenocarcinoma were also slighter higher among US-born Asian men (1.2 per 100,000) compared with foreign-born Asian men (0.7 per 100,000), P = 0.01. Rates of squamous cell carcinoma decreased for both US-born and foreign-born Asians during this period, whereas adenocarcinoma remained low and stable. These results provide better insight into the genetic and environmental factors affecting the changing incidence of esophageal cancer histologies in the United States and Asia.

Gene organization and characterization of the complete mitogenome of Hypsugo alaschanicus (Chiroptera: Vespertilionidae)

We sequenced and characterized the complete mitogenome of Hypsugo alaschanicus (Vespertilionidae) to provide more data for comparative mitogenomics of the genus Hypsugo. The mitogenome of H. alaschanicus is a circular molecule of 17,300 bp, consisting of a control region and a typically conserved set of 37 vertebrate genes containing 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes (12S rRNA and 16S rRNA). The mitogenome of H. alaschanicus is AT-biased, with a nucleotide composition of 34.1 A, 30.9 T, 22.4 C, and 12.6% G. In the 13 mitochondrial PCGs of H. alaschanicus, the start codon ATG is used in all PCGs, except Nd2 and Nd3 (which use ATT), and Nd5 (which uses ATA). Eight PCGs (Nd1, Cox1, Cox2, Atp8, Atp6, Nd4L, Nd5, and Nd6) use TAA as the stop codon, while the stop codon AGA occurs only in Cytb. Incomplete stop codons (T--) are used in the other four PCGs (Cox3, Nd2, Nd3, and Nd4). These findings contribute to our understanding of the nucleotide composition and molecular evolution of the mitogenomes of the genus Hypsugo, and provide more data for comparative mitogenomics and higher phylogeny in the family Vespertilionidae.

Detection and sequence analysis of the DNA repair gene RAD51 in the Korean spider Callobius koreanus (Amaurobiidae)

We identified a partial sequence (483 bp) of the RAD51 gene from the Korean spider Callobius koreanus. Sequence variation was found at one position during alignment with the human RAD51 gene sequence. This partial sequence included the region corresponding to exon 4 in the human RAD51 gene, which encodes 39 amino acids. These results show that the RAD51 gene is highly conserved between human and spiders.

Dipeptidyl peptidase 4 promotes epithelial cell transformation and breast tumourigenesis via induction of PIN1 gene expression

BACKGROUND AND PURPOSE

Dipeptidyl peptidase 4 (DPP4) is an aminopeptidase that is widely expressed in different cell types. Recent studies suggested that DPP4 plays an important role in tumour progression in several human malignancies. Here we have examined the mechanisms by which up-regulation of DPP4 expression causes epithelial transformation and mammary tumourigenesis.

EXPERIMENTAL APPROACH

Expression of DPP4 and the peptidylprolyl cis/trans isomerase, NIMA-interacting 1 (PIN1), and the cytotoxic effects of combined treatment with sitagliptin and juglone were investigated by immunohistochemistry, immunoblotting, real-time PCR, TUNEL and soft agar assays, using MCF7 cells. The effects of sitagliptin on tumour development in vivo were studied in the syngeneic 4T1 metastatic breast cancer model.

KEY RESULTS

Activity of the transcription factor E2F1 induced by EGF was enhanced by DPP4, thus increasing PIN1 expression. Furthermore, DPP4 enhanced MEK/ERK and JNK/c-Jun signalling induced by EGF, inducing AP-1 activity and epithelial cell transformation. In contrast, DPP4 silencing or DPP4 inhibition in MCF7 cells inhibited PIN1 expression via E2F1 activity induced by EGF, decreasing colony formation and inducing DNA fragmentation. In the syngeneic 4T1 metastatic breast cancer model, DPP4 overexpression increased tumour development, whereas treatment with sitagliptin and/or juglone suppressed it. Consistent with these observations, DPP4 levels were positively correlated with PIN1 expression in human breast cancer.

CONCLUSIONS AND IMPLICATIONS

DPP4 promoted EGF-induced epithelial cell transformation and mammary tumourigenesis via induction of PIN1 expression, suggesting that sitagliptin targeting of DPP4 could be a treatment strategy in patients with breast cancer.

Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment

Search results for nucleon decays p→e^{+}X, p→μ^{+}X, n→νγ (where X is an invisible, massless particle) as well as dinucleon decays np→e^{+}ν, np→μ^{+}ν, and np→τ^{+}ν in the Super-Kamiokande experiment are presented. Using single-ring data from an exposure of  273.4  kton·yr, a search for these decays yields a result consistent with no signal. Accordingly, lower limits on the partial lifetimes of τ_{p→e^{+}X}>7.9×10^{32} yr, τ_{p→μ^{+}X}>4.1×10^{32} yr, τ_{n→νγ}>5.5×10^{32} yr, τ_{np→e^{+}ν}>2.6×10^{32}  yr, τ_{np→μ^{+}ν}>2.2×10^{32} yr, and τ_{np→τ^{+}ν}>2.9×10^{31} yr at a 90% confidence level are obtained. Some of these searches are novel.

Interleukin-33/ST2 axis promotes epithelial cell transformation and breast tumorigenesis via upregulation of COT activity

Cytokines of the interleukin-1 (IL-1) family, such as IL-1α/β and IL-18, have pleiotropic activities in innate and adaptive immune responses in host defense and diseases. Insight into their biological functions helped develop novel therapeutic approaches to treat human inflammatory diseases. IL-33 is an important member of the IL-1 family of cytokines and is a ligand of the ST2 receptor, a member of the IL-1 receptor family. However, the role of the IL-33/ST2 axis in tumor growth and metastasis of breast cancer remains unclear. Here, we demonstrate that IL-33 is a critical tumor promoter during epithelial cell proliferation and tumorigenesis in the breast. IL-33 dose- and time-dependently increased Cancer Osaka Thyroid (COT) phosphorylation via ST2-COT interaction in normal epithelial and breast cancer cells. The IL-33/ST2/COT cascade induced the activation of the MEK-ERK (MEK-extracellular signal-regulated kinase), JNK-cJun (cJun N-terminal kinase-cJun) and STAT3 (signal transducer and activator of transcription 3) signaling pathways, followed by increased AP-1 and stat3 transcriptional activity. When small interfering RNAs of ST2 and COT were introduced into cells, IL-33-induced AP-1 and stat3 activity were significantly decreased, unlike that in the control cells. The inhibition of COT activity resulted in decreased IL-33-induced epithelial cell transformation, and knockdown of IL-33, ST2 and COT in breast cancer cells attenuated tumorigenicity of breast cancer cells. Consistent with these observations, ST2 levels were positively correlated with COT expression in human breast cancer. These findings provide a novel perspective on the role of the IL-33/ST2/COT signaling pathway in supporting cancer-associated inflammation in the tumor microenvironment. Therapeutic approaches that target this pathway may, therefore, effectively inhibit carcinogenesis in the breast.

Interleukin-33/ST2 axis promotes epithelial cell transformation and breast tumorigenesis via upregulation of COT activity

Cytokines of the interleukin-1 (IL-1) family, such as IL-1α/β and IL-18, have pleiotropic activities in innate and adaptive immune responses in host defense and diseases. Insight into their biological functions helped develop novel therapeutic approaches to treat human inflammatory diseases. IL-33 is an important member of the IL-1 family of cytokines and is a ligand of the ST2 receptor, a member of the IL-1 receptor family. However, the role of the IL-33/ST2 axis in tumor growth and metastasis of breast cancer remains unclear. Here, we demonstrate that IL-33 is a critical tumor promoter during epithelial cell proliferation and tumorigenesis in the breast. IL-33 dose- and time-dependently increased Cancer Osaka Thyroid (COT) phosphorylation via ST2-COT interaction in normal epithelial and breast cancer cells. The IL-33/ST2/COT cascade induced the activation of the MEK-ERK (MEK-extracellular signal-regulated kinase), JNK-cJun (cJun N-terminal kinase-cJun) and STAT3 (signal transducer and activator of transcription 3) signaling pathways, followed by increased AP-1 and stat3 transcriptional activity. When small interfering RNAs of ST2 and COT were introduced into cells, IL-33-induced AP-1 and stat3 activity were significantly decreased, unlike that in the control cells. The inhibition of COT activity resulted in decreased IL-33-induced epithelial cell transformation, and knockdown of IL-33, ST2 and COT in breast cancer cells attenuated tumorigenicity of breast cancer cells. Consistent with these observations, ST2 levels were positively correlated with COT expression in human breast cancer. These findings provide a novel perspective on the role of the IL-33/ST2/COT signaling pathway in supporting cancer-associated inflammation in the tumor microenvironment. Therapeutic approaches that target this pathway may, therefore, effectively inhibit carcinogenesis in the breast.

Classification by causes of dark circles and appropriate evaluation method of dark circles

BACKGROUND

Dark circles refer to a symptom that present darkness under the eyes. Because of improvement in the quality of life, the dark circles have been recognized as one of major cosmetic concerns. However, it is not easy to classify the dark circles because they have various causes.

METHODS

To select suitable instruments and detailed evaluation items, the dark circles were classified according to the causes through visual assessment, Wood's lamp test, and medical history survey for 100 subjects with dark circles. After the classification, were newly recruited for instrument conformity assessment. Through this, suitable instruments for dark circle evaluation were selected. We performed a randomized clinical trial for dark circles, a placebo-controlled double-blind study, using effective parameters of the instruments selected from the preliminary test.

RESULTS

Dark circles of vascular type (35%) and mixed type (54%), a combination of pigmented and vascular types, were the most common. Twenty four subjects with the mixed type dark circles applied the test product (Vitamin C 3%, Vitamin A 0.1%, Vitamin E 0.5%) and placebo on randomized split-face for 8 weeks. The effective parameters (L*, a, M.I., E.I., quasi L*, quasi a* and dermal thickness) were measured during the study period. Result showed that the L* value of Chromameter(®) , Melanin index (M.I.) of Mexameter(®) and quasi L* value obtained by image analysis improved with statistical significance after applying the test product compared with the placebo product.

CONCLUSION

We classified the dark circles according to the causes of the dark circles and verified the reliability of the parameter obtained by the instrument conformity assessment used in this study through the efficacy evaluation. Also based on this study, we were to suggest newly established methods which can be applied to the evaluation of efficacy of functional cosmetics for dark circles.

Endoplasmic reticulum (ER) stress protein responses in relation to spatio-temporal dynamics of astroglial responses to status epilepticus in rats

In the present study, we investigated whether endoplasmic reticulum (ER) stress is associated with neuronal- and astroglial-death in the hippocampus using LiCl-pilocarpine-induced status epilepticus (SE) rat model. Glucose-related protein (GRP) 78 and protein disulfide isomerase (PDI) expressions were transiently increased in CA1 neurons and dentate granule cells, and subsequently decreased in these cells following SE. GRP94 and calnexin (CNX) expression was gradually reduced in CA1 neurons, not in dentate granule cells. Phospho-protein kinase RNA (PKR)-like ER kinase (pPERK), phospho-eukaryotic initiation factor 2α (peIF2A) and CCAAT/enhancer-binding protein homologous protein (CHOP) immunoreactivities were observed in 17%, 12% and 7% of degenerating CA1 neurons, respectively. GRP 78 and PDI expressions were also up-regulated in reactive astrocytes within the CA1-3 regions. In the molecular layer of the dentate gyrus, PDI-positive astrocytes showed TUNEL signal, nuclear apoptosis inducing factor translocation and pPERK/peIF2A/CHOP immunoreactivities. Four weeks after SE, clasmatodendritic astrocytes showed pPERK peIF2A and CNX immunoreactivities without CHOP expression. These findings indicate that SE-induced ER stress may be associated with astroglial apoptosis and autophagic astroglial death in the regional-specific pattern.

Dipeptidyl peptidase 4 promotes epithelial cell transformation and breast tumourigenesis via induction of PIN1 gene expression

BACKGROUND AND PURPOSE

Dipeptidyl peptidase 4 (DPP4) is an aminopeptidase that is widely expressed in different cell types. Recent studies suggested that DPP4 plays an important role in tumour progression in several human malignancies. Here we have examined the mechanisms by which up-regulation of DPP4 expression causes epithelial transformation and mammary tumourigenesis.

EXPERIMENTAL APPROACH

Expression of DPP4 and the peptidylprolyl cis/trans isomerase, NIMA-interacting 1 (PIN1), and the cytotoxic effects of combined treatment with sitagliptin and juglone were investigated by immunohistochemistry, immunoblotting, real-time PCR, TUNEL and soft agar assays, using MCF7 cells. The effects of sitagliptin on tumour development in vivo were studied in the syngeneic 4T1 metastatic breast cancer model.

KEY RESULTS

Activity of the transcription factor E2F1 induced by EGF was enhanced by DPP4, thus increasing PIN1 expression. Furthermore, DPP4 enhanced MEK/ERK and JNK/c-Jun signalling induced by EGF, inducing AP-1 activity and epithelial cell transformation. In contrast, DPP4 silencing or DPP4 inhibition in MCF7 cells inhibited PIN1 expression via E2F1 activity induced by EGF, decreasing colony formation and inducing DNA fragmentation. In the syngeneic 4T1 metastatic breast cancer model, DPP4 overexpression increased tumour development, whereas treatment with sitagliptin and/or juglone suppressed it. Consistent with these observations, DPP4 levels were positively correlated with PIN1 expression in human breast cancer.

CONCLUSIONS AND IMPLICATIONS

DPP4 promoted EGF-induced epithelial cell transformation and mammary tumourigenesis via induction of PIN1 expression, suggesting that sitagliptin targeting of DPP4 could be a treatment strategy in patients with breast cancer.

ETB receptor-mediated MMP-9 activation induces vasogenic edema via ZO-1 protein degradation following status epilepticus

The blood-brain barrier (BBB) is formed by the endothelial cells with specialized tight junctions (TJs) lining the blood vessels and astroglial endfeet surrounding the blood vessels. Although BBB disruption during brain insults leads to vasogenic edema as one of the primary steps in the epileptogenic process, little is known about the molecular and physiological events concerning vasogenic edema formation. In the present study, status epilepticus (SE) changed the expressions and subcellular localizations of TJ proteins (claudin-5, occludin and zonula occludens-1 (ZO-1)) in endothelial cells of the rat piriform cortex. Among TJ proteins, the alteration in ZO-1 expression was relevant to endothelin B (ETB) receptor-mediated endothelial nitric oxide synthase (eNOS) activation, which increased matrix metalloproteinase-9 (MMP-9) activity. Indeed, BQ788 (an ETB receptor antagonist) effectively attenuated SE-induced vasogenic edema by inhibiting eNOS-mediated MMP-9 activation and ZO-1 protein degradation in endothelial cells, although astroglial endfeet were detached from endothelial cells. Therefore, we suggest that SE-induced ETB receptor/eNOS-mediated MMP-9 activation may lead to impairments of endothelial cell function via TJ protein degradation, which are involved in vasogenic edema formation independent of perivascular astroglial functions.

Evidence for Collective Multiparticle Correlations in p-Pb Collisions

The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in p-Pb and PbPb collisions over a wide pseudorapidity (η) range based on correlations among six or more charged particles. The p-Pb data, corresponding to an integrated luminosity of 35  nb-1, were collected during the 2013 LHC p-Pb run at a nucleon-nucleon center-of-mass energy of 5.02  TeV by the CMS experiment. A sample of semiperipheral PbPb collision data at √sNN=2.76  TeV, corresponding to an integrated luminosity of 2.5  μb-1 and covering a similar range of particle multiplicities as the p-Pb data, is also analyzed for comparison. The six- and eight-particle cumulant and the Lee-Yang zeros methods are used to extract the v2 coefficients, extending previous studies of two- and four-particle correlations. For both the p-Pb and PbPb systems, the v2 values obtained with correlations among more than four particles are consistent with previously published four-particle results. These data support the interpretation of a collective origin for the previously observed long-range (large Δη) correlations in both systems. The ratios of v2 values corresponding to correlations including different numbers of particles are compared to theoretical predictions that assume a hydrodynamic behavior of a p-Pb system dominated by fluctuations in the positions of participant nucleons. These results provide new insights into the multiparticle dynamics of collision systems with a very small overlapping region.

Design of in-flight fragment separator using high-power primary beams in the energy of a few hundred MeV/u

An in-flight fragment separator usually requires large acceptance and high momentum resolution to minimize the loss of a rare isotope beam of interest produced at a thin target, which is especially important when (238)U fission reactions in the energy of 200 MeV/u are used. The production target and beam dump are located in the pre-separator, where a beam power of up to 400 kW is dissipated. The area is surrounded by thick radiation shielding walls, which result in long drift spaces between adjacent magnetic components at various locations and an asymmetrical layout. Efforts have been made to minimize non-linear effects in the pre-separator beam optics with trials of different separator configurations and correction schemes using COSY Infinity and GICOSY. The main separator is configured to be mirror symmetric such that correction with hexapole and octupole coils can be more readily applied. The separator configuration was finalized to allow the facility design to proceed and the key components including superconducting magnets have been designed and prototyped. In addition, the separator design has been evaluated using LISE++ including a set of wedge degraders at dispersive focal planes to improve the yield and purity of selected isotope beam.