CRACD suppresses neuroendocrinal plasticity of lung adenocarcinoma

Tumor cell plasticity contributes to intratumoral heterogeneity and therapy resistance. Through cell plasticity, lung adenocarcinoma (LUAD) cells transform into neuroendocrinal (NE) tumor cells. However, the mechanisms of NE cell plasticity remain unclear. CRACD, a capping protein inhibitor, is frequently inactivated in cancers. CRACD knock-out (KO) de-represses NE-related gene expression in the pulmonary epithelium and LUAD cells. In LUAD mouse models, Cracd KO increases intratumoral heterogeneity with NE gene expression. Single-cell transcriptomic analysis showed that Cracd KO-induced NE plasticity is associated with cell de-differentiation and activated stemness-related pathways. The single-cell transcriptomes of LUAD patient tumors recapitulate that the distinct LUAD NE cell cluster expressing NE genes is co-enriched with SOX2, OCT4, and NANOG pathway activation, and impaired actin remodeling. This study reveals an unexpected role of CRACD in restricting NE cell plasticity that induces cell de-differentiation, providing new insights into cell plasticity of LUAD.

Inhibition of KIF20A suppresses the replication of influenza A virus by inhibiting viral entry

The influenza A virus (IAV) has caused several pandemics, and therefore there are many ongoing efforts to identify novel antiviral therapeutic strategies including vaccines and antiviral drugs. However, influenza viruses continuously undergo antigenic drift and shift, resulting in the emergence of mutated viruses. In turn, this decreases the efficiency of existing vaccines and antiviral drugs to control IAV infection. Therefore, this study sought to identify alternative therapeutic strategies targeting host cell factors rather than viruses to avoid infection by mutated viruses. Particularly, we investigated the role of KIF20A that is one of kinesin superfamily proteins in the replication of IAV. The KIF20A increased viral protein levels in IAV-infected cells by regulating the initial entry stage during viral infection. Furthermore, the KIF20A inhibitor significantly suppressed viral replication, which protected mice from morbidity and mortality. Therefore, our findings demonstrated that KIF20A is highly involved in the viral replication process and viral propagation both in vitro and in vivo, and could thus be used as a target for the development of novel antiviral drugs.

The gaps in health-adjusted life Expectancy (HALE) by income and region in Korea

 

This study aims to calculate the health-adjusted life expectancy (HALE) by using years lived with disability (YLD) from the national claims data, as well as to identify the differences and inequalities in sex, income level and region. The study was carried out on total population receiving national health insurance and medical benefits. We calculated incidence-based YLD for 260 disease groups, and used it as the number of healthy years lost to calculate HALE. We adopted the insurance premium to calculate the income as a proxy indicator. For the region classification, we chose 250 Korean municipal-level administrative districts. The primary outcome was HALE in the Korean population. The second outcome was the HALE’s gap in terms of sex, income, and region. Our results revealed that HALE increased from 2008 (68.89 years) to 2019 (70.58 years). HALE in males increased faster than that in females. HALE was higher in higher income levels. In 2019, the gap in HALE between Q1 and Q2, the lower income group, was about 5.70 years. The gap in females by income level was smaller than that in males. Moreover, the gap in HALE by region was found to increase. Results suggest that there is an inequality in YLD in terms of income level in Korea. Therefore, we need intensive management for the low-income group to increase HALE at the national level.

Key messages

• Males’ health level may be more sensitive to the socioeconomic level than females’ health level.

• In the 5th National Health Plan (HP2030), it was decided to set a target value for the overall goals based on this result.

Abstract 836: CRACD/CRAD, a tumor suppressor for gastric cancer development

Gastric cancer (GC) is the third most common cancer and the second most common cause of cancer death in Asia. The highest incidence rates are observed in Eastern Asia. To date, the comprehensive mechanism of GC initiation remains elusive. Here, we discovered CRACD (Capping Protein Inhibiting Regulator of Actin Dynamics/CRAD/KIAA1211) as a tumor suppressor, frequently inactivated in GC. To determine the pathologic roles of CRACD, we employed Cracd knock-out (KO) mice and gastric organoids (GOs). Intriguingly, Cracd KO mice and GOs displayed hyperplastic gastric epithelium. Mechanistically, CRACD is essential for stabilizing the cadherin-catenin-actin (CCA) complex. The loss of CRACD leads to the release and nuclear translocation of β-catenin for Wnt target gene transactivation. Indeed, the genetic ablation of Cracd hyperactivated Wnt/β-catenin signaling with the disruption of the CCA complex. The genes encoding the Receptor Tyrosine Kinase (RTK)-RAS signaling pathway and the TP53 are genetically altered in 60% and 50% of gastric adenocarcinomas, respectively. To define the genetic interaction of Cracd loss with the RTK-RAS and TP53 signaling, we established genetically engineered GOs models carrying Trp53 deletion and KrasG12D activation in combination with Cracd KO (CKP) or Cracd wild type (KP). Compared to KP, CKP GOs exhibited neoplasia, higher mucin deposition, and increased carcinoma embryonic antigen (CEA) expression, pathologically related to the poor prognosis in GC patients. Meanwhile, loss of Cracd significantly accelerated the growth of CKP GOs with increased stemness. Furthermore, the CKP cell line derived from GOs exhibited relatively poor prognosis features of GC than KP cells in the xenograft models, represented by boosted tumor size and weight, poor differentiation, hyperplasia, increased CEA, and mucin secretion. Together, we identified CRACD as a tumor suppressor, of which inactivation contributes to GC initiation and progression, which may be translated into the development of a biomarker-guided regimen for CRACD mutations-associated GC patients.

Citation Format: Gengyi Zou, Yuanjian Huang, Kyung Pil Ko, Shengzhe Zhang, Bong Jun Kim, Jie Zhang, Sohee Jun, Youn-Sang Jung, Biyun Zheng, Jae-Il Park. CRACD/CRAD, a tumor suppressor for gastric cancer development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 836.

Abstract P5-08-15: Overcoming mTOR inhibitor resistance by targeting the lysosomal deregulation

Increasing evidence suggests that the deregulated lysosomes contribute to tumorigenesis and therapeutic resistance. However, its underlying mechanisms remain elusive. Here, we identify transmembrane protein 9 (TMEM9) as a regulator involved in lysosomal metabolism and mammary tumorigenesis. The TMEM9 gene is markedly amplified in breast cancer, correlated with its transcriptional upregulation. We uncovered that Tmem9 knock-out inhibited mammary tumorigenesis in genetically engineered mouse models. Consistently, TMEM9 depletion suppressed the proliferation of breast cancer cells highly expressing TMEM9. Conversely, the ectopic expression of TMEM9 in TMEM9 low breast cancer cells promoted cell proliferation. The lysosome purification and proteomics approach showed that TMEM9 physically and functionally interacts with LAMTOR4, a subunit of the Ragulator complex, to hyperactivate mTOR signaling in breast cancer. Moreover, the combination of TMEM9-v-ATPase inhibitors with mTOR inhibitors exhibited the synergistic growth inhibition of breast cancer cells in vitro and in vivo. Our results reveal that the TMEM9-v-ATPase axis is not only a biomarker for resistance to mTOR inhibition therapy but also a molecular target overcoming mTOR inhibitor resistance.

Citation Format: Shengzhe Zhang, Sung Ho Lee, Litong Nie, Youn-Sang Jung, Sohee Jun, Jie Zhang, Esther M Lien, Junjie Chen, Jae-Il Park. Overcoming mTOR inhibitor resistance by targeting the lysosomal deregulation [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-08-15.

Mucin in cancer: a stealth cloak for cancer cells

Mucins are high molecular-weight epithelial glycoproteins and are implicated in many physiological processes, including epithelial cell protection, signaling transduction, and tissue homeostasis. Abnormality of mucus expression and structure contributes to biological properties related to human cancer progression. Tumor growth sites induce inhospitable conditions. Many kinds of research suggest that mucins provide a microenvironment to avoid hypoxia, acidic, and other biological conditions that promote cancer progression. Given that the mucus layer captures growth factors or cytokines, we propose that mucin helps to ameliorate inhospitable conditions in tumor-growing sites. Additionally, the composition and structure of mucins enable them to mimic the surface of normal epithelial cells, allowing tumor cells to escape from immune surveillance. Indeed, human cancers such as mucinous carcinoma, show a higher incidence of invasion to adjacent organs and lymph node metastasis than do non-mucinous carcinoma. In this mini-review, we discuss how mucin provides a tumor-friendly environment and contributes to increased cancer malignancy in mucinous carcinoma.

Enhanced wound healing using a 3D printed VEGF-mimicking peptide incorporated hydrogel patch in a pig model

There is a need for effective wound healing through rapid wound closure, reduction of scar formation, and acceleration of angiogenesis. Hydrogel is widely used in tissue engineering, but it is not an ideal solution because of its low vascularization capability and poor mechanical properties. In this study, gelatin methacrylate (GelMA) was tested as a viable option with tunable physical properties. GelMA hydrogel incorporating a vascular endothelial growth factor (VEGF) mimicking peptide was successfully printed using a three-dimensional (3D) bio-printer owing to the shear-thinning properties of hydrogel inks. The 3D structure of the hydrogel patch had high porosity and water absorption properties. Furthermore, the bioactive characterization was confirmed by cell culture with mouse fibroblasts cell lines (NIH 3T3) and human umbilical vein endothelial cells. VEGF peptide, which is slowly released from hydrogel patches, can promote cell viability, proliferation, and tubular structure formation. In addition, a pig skin wound model was used to evaluate the wound-healing efficacy of GelMA-VEGF hydrogel patches; the results suggest that the GelMA-VEGF hydrogel patch can be used for wound dressing.

PAF remodels the DREAM complex to bypass cell quiescence and promote lung tumorigenesis

The DREAM complex orchestrates cell quiescence and the cell cycle. However, how the DREAM complex is deregulated in cancer remains elusive. Here, we report that PAF (PCLAF/KIAA0101) drives cell quiescence exit to promote lung tumorigenesis by remodeling the DREAM complex. PAF is highly expressed in lung adenocarcinoma (LUAD) and is associated with poor prognosis. Importantly, Paf knockout markedly suppressed LUAD development in mouse models. PAF depletion induced LUAD cell quiescence and growth arrest. PAF is required for the global expression of cell-cycle genes controlled by the repressive DREAM complex. Mechanistically, PAF inhibits DREAM complex formation by binding to RBBP4, a core DREAM subunit, leading to transactivation of DREAM target genes. Furthermore, pharmacological mimicking of PAF-depleted transcriptomes inhibited LUAD tumor growth. Our results unveil how the PAF-remodeled DREAM complex bypasses cell quiescence to promote lung tumorigenesis and suggest that the PAF-DREAM axis may be a therapeutic vulnerability in lung cancer.

TMEM9-v-ATPase Activates Wnt/β-Catenin Signaling Via APC Lysosomal Degradation for Liver Regeneration and Tumorigenesis

BACKGROUND AND AIMS

How Wnt signaling is orchestrated in liver regeneration and tumorigenesis remains elusive. Recently, we identified transmembrane protein 9 (TMEM9) as a Wnt signaling amplifier.

APPROACH AND RESULTS

TMEM9 facilitates v-ATPase assembly for vesicular acidification and lysosomal protein degradation. TMEM9 is highly expressed in regenerating liver and hepatocellular carcinoma (HCC) cells. TMEM9 expression is enriched in the hepatocytes around the central vein and acutely induced by injury. In mice, Tmem9 knockout impairs hepatic regeneration with aberrantly increased adenomatosis polyposis coli (Apc) and reduced Wnt signaling. Mechanistically, TMEM9 down-regulates APC through lysosomal protein degradation through v-ATPase. In HCC, TMEM9 is overexpressed and necessary to maintain β-catenin hyperactivation. TMEM9-up-regulated APC binds to and inhibits nuclear translocation of β-catenin, independent of HCC-associated β-catenin mutations. Pharmacological blockade of TMEM9-v-ATPase or lysosomal degradation suppresses Wnt/β-catenin through APC stabilization and β-catenin cytosolic retention.

CONCLUSIONS

Our results reveal that TMEM9 hyperactivates Wnt signaling for liver regeneration and tumorigenesis through lysosomal degradation of APC.

Blockers of Wnt3a, Wnt10a, or β-Catenin Prevent Chemotherapy-Induced Neuropathic Pain In Vivo

Although chemotherapy is a key cancer treatment, many chemotherapeutic drugs produce chronic neuropathic pain, called chemotherapy-induced neuropathic pain (CINP), which is a dose-limiting adverse effect. To date, there is no medicine that prevents CINP in cancer patients and survivors. We determined whether blockers of the canonical Wnt signaling pathway prevent CINP. Neuropathic pain was induced by intraperitoneal injection of paclitaxel (PAC) on four alternate days in male Sprague-Dawley rats or male Axin2-LacZ knock-in mice. XAV-939, LGK-974, and iCRT14, Wnt/β-catenin blockers, were administered intraperitoneally as a single or multiple doses before or after injury. Mechanical allodynia, phosphoproteome profiling, Wnt ligands, and inflammatory mediators were measured by von Frey filament, phosphoproteomics, reverse transcription-polymerase chain reaction, and Western blot analysis. Localization of β-catenin was determined by immunohistochemical analysis in the dorsal root ganglia (DRGs) in rats and human. Our phosphoproteome profiling of CINP rats revealed significant phosphorylation changes in Wnt signaling components. Importantly, repeated systemic injections of XAV-939 or LGK-974 prevented the development of CINP in rats. In addition, XAV-939, LGK-974, and iCRT14 ameliorated CINP. PAC increased Wnt3a and Wnt10a, activated β-catenin in DRG, and increased monocyte chemoattractant protein-1 and interleukin-1β in DRG. PAC also upregulated rAxin2 in mice. Furthermore, β-catenin was expressed in neurons, including calcitonin gene-related protein-expressing neurons and satellite cells in rat and human DRG. In conclusion, chemotherapy increases Wnt3a, Wnt10a, and β-catenin in DRG and their pharmacological blockers prevent and ameliorate CINP, suggesting a target for the prevention and treatment of CINP.

A new aspect of an old friend: the beneficial effect of metformin on anti-tumor immunity

T-cell-based cancer immunotherapies, such as immune checkpoint blockers (ICBs) and chimeric antigen receptor (CAR)-T-cells, have significant anti-tumor effects against certain types of cancer, providing a new paradigm for cancer treatment. However, the activity of tumor infiltrating T-cells (TILs) can be effectively neutralized in the tumor microenvironment (TME) of most solid tumors, rich in various immunosuppressive factors and cells. Therefore, to improve the clinical outcomes of established T-cell-based immunotherapy, adjuvants that can comprehensively relieve multiple immunosuppressive mechanisms of TME are needed. In this regard, recent studies have revealed that metformin has several beneficial effects on anti-tumor immunity. In this mini-review, we understand the immunosuppressive properties of TME and how metformin comprehensively enhances anti-tumor immunity. Finally, we will discuss this old friend’s potential as an adjuvant for cancer immunotherapy.

Effects of anti-resorptive drugs on implant survival and peri-implantitis in patients with existing osseointegrated dental implants: a retrospective cohort study

The effect of anti-resorptive drug (ARD) usage among patients with successful dental implant osseointegration is controversial. This study showed an increased risk of implant failure in ARD users. Risk factors included pre-existing marginal bone loss, overdenture, diabetes, and a short interval between implant placement and ARD administration.

INTRODUCTION

This retrospective study aimed to determine whether anti-resorptive drug (ARD) usage increased risk of implant failure among patients with successful implant osseointegration. Additionally, the study investigated risk factors that affected implant survival rate in ARD users.

METHODS

Eighty ARD users with 344 implants who had more than 12 months of follow-up from the initiation of ARD treatment during the period between 2008 and 2017 were included, along with 80 non-ARD users from the same period. The primary outcome was dental implant survival. Kaplan-Meier survival curves and Cox proportional hazard models were used for survival analysis.

RESULTS

Average follow-up was 85.3 months. Implant survival rates were 89.83% in ARD users and 96.03% in non-ARD users. In the univariate Cox proportional hazard model, risk of implant failure was significantly higher in patients with pre-existing marginal bone loss (MBL), diabetes, and concurrent bone augmentation. However, risk of implant failure was significantly lower when the interval between implant placement and ARD administration was < 36 months. Compared with overdenture, single crown and fixed splinted users had lower risk of implant failure. In multivariate analysis, variables including pre-existing MBL, diabetes, < 36-month interval between implant placement and ARD treatment, and usage of fixed splinted prosthesis were significantly associated with increased risk of implant failure.

CONCLUSIONS

ARD administration after implant osseointegration was correlated with a reduced implant survival rate. Pre-existing MBL, diabetes, type of final prosthesis, and the interval between implant placement and initiation of ARD administration influenced risk of implant failure.

Wnt signaling in cancer: therapeutic targeting of Wnt signaling beyond β-catenin and the destruction complex

Wnt/β-catenin signaling is implicated in many physiological processes, including development, tissue homeostasis, and tissue regeneration. In human cancers, Wnt/β-catenin signaling is highly activated, which has led to the development of various Wnt signaling inhibitors for cancer therapies. Nonetheless, the blockade of Wnt signaling causes side effects such as impairment of tissue homeostasis and regeneration. Recently, several studies have identified cancer-specific Wnt signaling regulators. In this review, we discuss the Wnt inhibitors currently being used in clinical trials and suggest how additional cancer-specific regulators could be utilized to treat Wnt signaling-associated cancer.

Abstract P4-14-04: Time course changes in serum FSH, estradiol, and menstruation restoration in premenopausal patients with breast cancer taking adjuvant tamoxifen after completing chemotherapy: A report from the ASTRRA study

BACKGROUND

Assessment of restoration of ovarian function after chemotherapy is critical with respect to the initiation of different types of endocrine treatment in young high risk breast cancer patients

METHODS

In total, 1289 women who remained premenopausal or resumed premenopausal status after chemotherapy were randomized to receive 5 years of tamoxifen or 5 years of tamoxifen plus 2 years of ovarian suppression. The patients who did not resume menstruation were followed up for 2 years with tamoxifen treatment after finishing chemotherapy. Prospectively collected consecutive post-chemotherapy hormone and menstruation data were available for 705 breast cancer patients who enrolled tamoxifen-only treatment group or did not resume menstruation during follow up. This analysis evaluated the proportion of patients with pre-menopausal FSH levels (&lt;30 mIU/ml), E2 levels (340 pg/ml), and menstruation at any time point during treatment with tamoxifen.

RESULTS

During 5 years of tamoxifen treatment after chemotherapy for premenopausal breast cancer patients, 62% of patients resumed menstruation. Menstruation returned in 92% of patients under 35 years old but only in 31% of patients over 45 years old. Ovarian function, defined by serum FSH and E2 levels, resumed in 94% and 65% of patients, respectively, over 5 years. Most patients achieved ovarian function restoration during the first 2 years after chemotherapy, with 47.1% resuming menstruation and 86.2% and 50.3% achieving pre-menopausal FSH and E2 levels, respectively, in the first 2 years. Clinical factors related to menstruation restoration were younger age (HR = 6.38, 95% CI 1.33-3.47), 6 month hormone profile after chemotherapy (FSH&lt;30: HR=1.67, 95% CI 1.28-2.17; E2 &gt;40: HR=2.96, 95% CI 2.25-3.89), and anthracycline without taxane chemotherapy (HR=1.63, 95% CI 1.25-2.13).

CONCLUSIONS

During 5 years of tamoxifen treatment after chemotherapy, half of patients experienced menstruation restoration, including most very young patients under 35 years. The majority of patients experienced menstruation restoration in the first 2 years of tamoxifen treatment.

Citation Format: Kim HJ, Noh WC, Nam SJ, Park B-w, Lee ES, Im SA, Jung YS, Yoon JH, Kang SS, Park KH, Lee S-J, Jung J, Lee MH, Cho SH, Kim SY, Kim H-A, Han S-H, Han W, Hur MH, Ahn SH. Time course changes in serum FSH, estradiol, and menstruation restoration in premenopausal patients with breast cancer taking adjuvant tamoxifen after completing chemotherapy: A report from the ASTRRA study [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 P4-14-04.

Quiescence Exit of Tert+ Stem Cells by Wnt/β-Catenin Is Indispensable for Intestinal Regeneration

Fine control of stem cell maintenance and activation is crucial for tissue homeostasis and regeneration. However, the mechanism of quiescence exit of Tert⁺ intestinal stem cells (ISCs) remains unknown. Employing a Tert knockin (Tert^TCE/+) mouse model, we found that Tert⁺ cells are long-term label-retaining self-renewing cells, which are partially distinguished from the previously identified +4 ISCs. Tert⁺ cells become mitotic upon irradiation (IR) injury. Conditional ablation of Tert⁺ cells impairs IR-induced intestinal regeneration but not intestinal homeostasis. Upon IR injury, Wnt signaling is specifically activated in Tert⁺ cells via the ROS-HIFs-transactivated Wnt2b signaling axis. Importantly, conditional knockout of β-catenin/Ctnnb1 in Tert⁺ cells undermines IR-induced quiescence exit of Tert⁺ cells, which subsequently impedes intestinal regeneration. Our results that Wnt-signaling-induced activation of Tert⁺ ISCs is indispensable for intestinal regeneration unveil the underlying mechanism for how Tert⁺ stem cells undergo quiescence exit upon tissue injury.

Abstract 4473: Tumorigenesis by deregulation of CRAD-controlled cytoskeleton dynamics

Epithelial cell behavior and homeostasis are mainly modulated by the cytoskeleton and cell adhesion. However, much concerning epithelial cell deregulation in cancer remains unknown. We identified Cancer-related Regulator of Actin Dynamics (CRAD) as frequently mutated or transcriptionally downregulated in colorectal cancer. We found that CRAD is a capping protein inhibitor and stabilizes the cadherin-catenin-actin (CCA) complex. CRAD inactivation disrupts the CCA complex via inhibiting actin polymerization, liberating β-catenin and aberrantly activating Wnt pathway. In mice, CRAD knockout induces the loss of epithelial cell integrity and hyperactivates Wnt signaling, resulting in intestinal adenoma development. With APC mutation, CRAD knockout induces and accelerates mucinous and invasive adenoma development in the colorectum. These results define CRAD as a new tumor suppressor, of which inactivation deregulates the cytoskeleton and hyperactivates Wnt signaling, initiating mucinous intestinal tumorigenesis. Our study reveals the unexpected roles of an actin cytoskeletal regulator in maintaining epithelial cell integrity.

Citation Format: Youn-Sang Jung, Wenqi Wang, Sohee Jun, Jie Zhang, Mrianl Srivastava, Moon Jong Kim, Esther M. Lien, Joan Shang, Pierre D. McCrea, Songlin Zhang, Junjie Chen, Jae-Il Park. Tumorigenesis by deregulation of CRAD-controlled cytoskeleton dynamics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4473.

Prevention effect of rare ginsenosides against stress-hormone induced MTOC amplification

Stress has been suggested as one of important cause of human cancer without molecular biological evidence. Thus, we test the effect of stress-related hormones on cell viability and mitotic fidelity. Similarly to estrogen, stress hormone cortisol and its relative cortisone increase microtubule organizing center (MTOC) number through elevated expression of γ-tubulin and provide the Taxol resistance to human cancer cell lines. However, these effects are achieved by glucocorticoid hormone receptor (GR) but not by estrogen receptor (ER). Since ginsenosides possess steroid-like structure, we hypothesized that it would block the stress or estrogen-induced MTOC amplification and Taxol resistance. Among tested chemicals, rare ginsenoside, CSH1 (Rg6) shows obvious effect on inhibition of MTOC amplification, γ-tubulin induction and Taxol resistance. Comparing to Fulvestant (FST), ER-α specific inhibitor, this chemical can block the cortisol/cortisone-induced MTOC deregulation as well as ER-α signaling. Our results suggest that stress hormone induced tumorigenesis would be achieved by MTOC amplification, and CSH1 would be useful for prevention of stress-hormone or steroid hormone-induced chromosomal instability.

Clinical Characteristics of Patients with Pseudo-Subarachnoid Haemorrhage who were Successfully Resuscitated from Out-of-Hospital Cardiopulmonary Arrest

Introduction

Pseudo-subarachnoid haemorrhage (PSAH) is a rare neuroradiological finding seen in patients with diffuse cerebral edemas. We investigated clinical characteristics and risk factors for the development of PSAH.

Method

The successfully resuscitated patients in emergency department were classified into two groups: those with pseudo-SAH [PSAH (+)] and those without pseudo-SAH [PSAH (-)]. Clinical variables were analysed.

Results

Pseudo-SAH was found in 31.6% of patients. PSAH was more common in males (p=0.042). The mean age was 39.9±10.3 years in the PSAH (+) group and 54.4±22.0 years in the PSAH (-) group (p=0.038). Outcomes measured by Cerebral Performance Category score were also significantly different between the two groups (p=0.037). Logistic regression analysis found that serum lactate concentration and duration of anoxia were associated with the development of PSAH (with odds ratios and p values of 1.92, p=0.01 and 1.13, p=0.02, respectively).

Conclusions

PSAH itself is a phenomenon that could be seen in post-resuscitation encephalopathy as a consequence of severe anoxic insult.

Systematic review with meta-analysis: the efficacy of vonoprazan-based triple therapy on Helicobacter pylori eradication

BACKGROUND

In order to increase eradication rates, vonoprazan, a novel potassium-competitive acid blocker, has been used in Helicobacter pylori eradication therapy.

AIM

To summarise the results of the efficacy of vonoprazan-based triple therapy, helping clinicians to better understand the benefit of vonoprazan in the treatment of H. pylori infection.

METHODS

We conducted a systematic literature search on MEDLINE, EMBASE, and the Cochrane Library using the primary keywords "vonoprazan," "takecab", "TAK-438," "potassium," "competitive," "potassium-competitive," "Helicobacter," and "pylori." Studies were included if they evaluated the eradication rate between the vonoprazan-based and proton pump inhibitor (PPI)-based triple therapies.

RESULTS

Ten studies and 10 644 patients were evaluated. The crude H. pylori eradication rate determined by intention-to-treat analysis was 87.9% and 72.8% in the vonoprazan-based triple therapy and PPI-based triple therapy respectively. The eradication rate of the vonoprazan-based triple therapy was superior to that of the PPI-based triple therapy (pooled risk ratio [RR] [95% confidence interval (CI)]=1.19 [1.15-1.24]) In addition, there was no significant difference in dropout rate due to adverse event between the regimens (pooled RR of the vonoprazan-based triple therapy [95% CI]=0.69 [0.23-2.03]). The incidence of any adverse events also did not differ between the regimens (pooled RR [95% CI]=1.02 [0.78-1.34]).

CONCLUSIONS

The vonoprazan-based triple therapy showed superior efficacy in terms of H. pylori eradication as compared to the PPI-based triple therapy. In addition, the vonoprazan-based triple therapy showed comparable tolerability and incidence of adverse events.

Mandibular step osteotomy using CAD/CAM-derived surgical splint: case report

Mandibular step osteotomy is a useful technique for large mandibular setbacks. We report a case of a patient who had a mandibular step osteotomy using a CAD/CAM-derived wafer for mandibular setback with reduction of the arch.

Periorbital melasma: Hierarchical cluster analysis of clinical features in Asian patients

BACKGROUND

Studies have shown melasma lesions to be distributed across the face in centrofacial, malar, and mandibular patterns. Meanwhile, however, melasma lesions of the periorbital area have yet to be thoroughly described.

METHODS

We analyzed normal and ultraviolet light-exposed photographs of patients with melasma. The periorbital melasma lesions were measured according to anatomical reference points and a hierarchical cluster analysis was performed.

RESULTS

The periorbital melasma lesions showed clinical features of fine and homogenous melasma pigmentation, involving both the upper and lower eyelids that extended to other anatomical sites with a darker and coarser appearance. The hierarchical cluster analysis indicated that patients with periorbital melasma can be categorized into two clusters according to the surface anatomy of the face. Significant differences between cluster 1 and cluster 2 were found in lateral distance and inferolateral distance, but not in medial distance and superior distance. Comparing the two clusters, patients in cluster 2 were found to be significantly older and more commonly accompanied by melasma lesions of the temple and medial cheek.

CONCLUSION

Our hierarchical cluster analysis of periorbital melasma lesions demonstrated that Asian patients with periorbital melasma can be categorized into two clusters according to the surface anatomy of the face.

Interruption of progerin-lamin A/C binding ameliorates Hutchinson-Gilford progeria syndrome phenotype

Hutchinson-Gilford progeria syndrome (HGPS) is a rare autosomal dominant genetic disease that is caused by a silent mutation of the LMNA gene encoding lamins A and C (lamin A/C). The G608G mutation generates a more accessible splicing donor site than does WT and produces an alternatively spliced product of LMNA called progerin, which is also expressed in normal aged cells. In this study, we determined that progerin binds directly to lamin A/C and induces profound nuclear aberrations. Given this observation, we performed a random screening of a chemical library and identified 3 compounds (JH1, JH4, and JH13) that efficiently block progerin-lamin A/C binding. These 3 chemicals, particularly JH4, alleviated nuclear deformation and reversed senescence markers characteristic of HGPS cells, including growth arrest and senescence-associated β-gal (SA-β-gal) activity. We then used microarray-based analysis to demonstrate that JH4 is able to rescue defects of cell-cycle progression in both HGPS and aged cells. Furthermore, administration of JH4 to LmnaG609G/G609G-mutant mice, which phenocopy human HGPS, resulted in a marked improvement of several progeria phenotypes and an extended lifespan. Together, these findings indicate that specific inhibitors with the ability to block pathological progerin-lamin A/C binding may represent a promising strategy for improving lifespan and health in both HGPS and normal aging.

LIG4 mediates Wnt signalling-induced radioresistance

Despite the implication of Wnt signalling in radioresistance, the underlying mechanisms are unknown. Here we find that high Wnt signalling is associated with radioresistance in colorectal cancer (CRC) cells and intestinal stem cells (ISCs). We find that LIG4, a DNA ligase in DNA double-strand break repair, is a direct target of β-catenin. Wnt signalling enhances non-homologous end-joining repair in CRC, which is mediated by LIG4 transactivated by β-catenin. During radiation-induced intestinal regeneration, LIG4 mainly expressed in the crypts is conditionally upregulated in ISCs, accompanied by Wnt/β-catenin signalling activation. Importantly, among the DNA repair genes, LIG4 is highly upregulated in human CRC cells, in correlation with β-catenin hyperactivation. Furthermore, blocking LIG4 sensitizes CRC cells to radiation. Our results reveal the molecular mechanism of Wnt signalling-induced radioresistance in CRC and ISCs, and further unveils the unexpected convergence between Wnt signalling and DNA repair pathways in tumorigenesis and tissue regeneration.

The Wnt/β-catenin signalling pathway contributes to radio resistance in intestinal stem cells but the underlying mechanism is currently unknown. In this study, the authors demonstrate that LIG4, a DNA ligase involved in the DNA repair process, is a direct target of β-catenin and it specifically mediates non-homologous end joining repair in colorectal cancer cells.

Abstract P5-12-08: Time course of changes in serum FSH, serum estradiol, and menstruation in premenopausal patients with breast cancer taking tamoxifen after completing chemotherapy: A report from the ASTRRA study

BACKGROUND

Ovarian suppression with tamoxifen after chemotherapy is a promising therapeutic approach, particularly in young, high-risk breast cancer patients. Assessment of restoration of ovarian function is important with respect to the initiation of ovarian suppression.

METHODS

In total, 1289 women who remained or resumed premenopausal status after chemotherapy were randomized to receive 5 years of tamoxifen or 5 years of tamoxifen plus 2 years of ovarian suppression. Prospectively collected hormone data were available for 24 months after completing chemotherapy for 267 breast cancer patients without ovarian suppression.

RESULTS

At 6 months, a premenopausal status was identified in 56.6%, 36%, and 16.2% of patients using serum FSH, E2, and with menstruation bleeding, respectively, and about 30% more women achieved ovarian restoration using all three parameters during the 24-month follow-up. Ovarian function restoration differed significantly according to age group (log-rank, P&lt;0.001 for all definitions). At 6 months, the distribution of patients according to hormone levels was as follows: group 1 (FSH &lt;30 mIU/ml, E2 &gt;20 pg/ml), 28.0%; group 2 (FSH &lt;30 mIU/ml, E2 ≤20 pg/ml), 28.4%; group 3 (FSH ≥30 mIU/ml, E2 &gt;20 pg/ml), 8.0%; and group 4 (FSH ≥30 mIU/ml, E2 ≤20 pg/ml), 35.6%. During the 24-month follow-up, the prevalence of menstruation restoration was higher in group 1 (71.6%) than in the other three groups. Restoration of serum E2 and menstrual bleeding occurred in 44% and 33% of patients in group 2, respectively; the corresponding percentages in group 4 were 40.6% and 28.7% (P&lt;0.001).

CONCLUSIONS

Ovarian function should be monitored using serum FSH, serum E2, and menstruation history for at least 24 months after completing chemotherapy during tamoxifen treatment to establish eligibility for ovarian suppression.

Citation Format: Kim HJ, Ahn SH, Nam SJ, Park SH, Ro JS, Im SA, Jung YS, Noh WC. Time course of changes in serum FSH, serum estradiol, and menstruation in premenopausal patients with breast cancer taking tamoxifen after completing chemotherapy: A report from the ASTRRA study. [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 P5-12-08.

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.

Evaluation of lymph node status after neoadjuvant chemotherapy in breast cancer patients: comparison of diagnostic performance of ultrasound, MRI and ¹⁸F-FDG PET/CT

Objective:

To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities.

Methods:

From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis.

Results:

After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p < 0.001 and p = 0.009, respectively) and MRI (p = 0.045 and p = 0.036, respectively). The percentage diameter decrease, size of tumour deposit in LN, progesterone receptor, HER2 and histological grade were significantly associated with the diagnostic performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95–57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407–29.737).

Conclusion:

Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with diagnostic performance of ultrasound and PET/CT.

Advances in knowledge:

This study is about the diagnostic performance of ultrasound, MRI, PET/CT and combination of each imaging modality for the evaluation of metastatic ALN after NAC. Of many histopathological factors, only the size of tumour deposit within ALN was an independent factor associated with the diagnostic performance of ultrasound and PET/CT.

Elevated estrogen receptor-α in VHL-deficient condition induces microtubule organizing center amplification via disruption of BRCA1/Rad51 interaction

Since loss of VHL is frequently detected early phase genetic event in human renal cell carcinoma, pVHL is assumed to be indispensable for suppression of tumor initiation step. However, induction of HIF-1α, target of pVHL E3 ligase, is more adequate to angiogenesis step after tumor mass formation. Concerning this, it has been reported that pVHL is involved in centrosome location during metaphase and regulates ER-α signaling. Here, we provide the evidences that pVHL-mediated ER-α suppression is critical for microtubule organizing center (MTOC) maintaining and elevated ER-α promotes MTOC amplification through disruption of BRCA1-Rad51 interaction. In fact, numerous MTOC in VHL- or BRCA1-deficient cells are reduced by Fulvestrant, inhibitor of ER-α expression as well as antagonist. In addition, we reveal that activation of ER signaling can increase γ-tubulin, core factor of TuRC and render the resistance to Taxol. Thus, Fulvestrant but not Tamoxifen, antagonist against ER-α, can restore the Taxol sensitivity in VHL- or BRCA1-deficient cells. Our results suggest that pVHL-mediated ER-α suppression is important for regulation of MTOC as well as drug resistance.

Abstract 5090: Estrogen receptor-alpha promotes multi-centrosomes by inhibition of BRCA1-Rad51 binding

Von Hippel Lindau gene (VHL) is frequently deleted in renal cell carcinoma and known to be negative regulator of Hypoxia inducible factor-1 (HIF-1). However, its tumor suppressive functions has not been fully explained by HIF-1 suppression, because loss of pVHL is appeared in initial stage of RCC tumorigenesis and induces the defect in cytokinesis or centrosome instability. Concerning this, we previously revealed that estrogen receptor-alpha is primary target of E3 ligase function of pVHL. In this study, we demonstrate that ER-α is responsible for mitotic defect and drug resistance in VHL-deficient cells. Activated ER-α can interact with BRCA1 or Rad51 and disrupt the BRCA1-Rad51-mediated centrosome maintaining. Thus, VHL-deficient cells, like as BRCA1-deficient cells, possessed multi-centrosome and multi-nucleated phenotypes. In addition, multi-centrosomal features rendered the resistance to Taxol. Since it is mediated by ER-α in nucleus, blocking of ER-α translocation by specific inhibitor, Faslodex, can ameliorate multi-centrosomes and induce Taxol sensitivity in RCC and BRCA1-deficient breast cancers. These results suggest that pVHL is critical for proper cell division and suppression of ER-α in RCC and BRCA1-deficient breast cancer is one of useful strategy for improving the drug sensitivity.

Citation Format: Youn-Sang Jung, Ho-Young Chun, Tae-Gyun Woo, Bum-Joon Park. Estrogen receptor-alpha promotes multi-centrosomes by inhibition of BRCA1-Rad51 binding. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5090. doi:10.1158/1538-7445.AM2014-5090

Development of inorganic and organic hybrid nanocoating based on carbon nanotubes for corrosion resistance

In this study, we report the synthesis and characterization of novel hybrid nanocoating based on carbon nanotubes (CNTs) on anodized aluminum surfaces (AAO). The hybrid nanocoating was deposited by number of methods which include spray coating, spin coating and dip coating. The bonding of nanocoating with metal surface is an important parameter for successful modification of the metal surfaces. The improved adhesion of nanocoating on metal surfaces could be attributed to chemical bonding of sol-gel nanocoating with anodized surfaces. The nanocoated anodized aluminum surfaces showed superior adhesion and excellent anticorrosive properties. The nanocoated panels showed enhanced galvanic protection comparable to 80% of titanium metal as determined by galvanic corrosion measurements. It also showed higher thermal conductivities than stainless steel and bare anodized surfaces.

Abstract 4602: Blocking of p14/ARF and DX2 binding by novel small chemical can improve the chemo-sensitivity of small cell lung cancer and non-small cell lung carcinoma

In recent, it has been reported that alternative splicing variant of AIMP2, AIMP2/DX2 (DX2), is frequently expressed in human lung cancer and is related with p53-mediated tumor suppression pathway. Here we show that DX2 can promote tumor progression and increase incidence, cooperatively with oncogenic K-Ras in transgenic mouse model. Moreover, it can induce small cell lung carcinoma (SCLC) as well as contribute to progression of non-small cell lung carcinoma (NSCLC). In fact, DX2 expression is elevated in human small cell lung cancer cell lines. Based on the cellular localization and responsibility of si-DX2, we revealed that DX2 is an inhibitor of p14/ARF. Elimination of DX2 can induce p14/ARF expression and DX2 Transgenic (Tg) mouse cells show the low expression of p19/ARF. Since DX2, but not its original product AIMP2, is selectively interacted with p14/ARF, we screened the specific binding inhibitor and obtained the single compound (SLC36) from about 9000 chemicals. This chemical can block the interaction of p14/ARF-DX2 and also AIMP2-DX2, but not the binding of p14/ARF-p53 or AIMP2-p53. In addition, it can induce p14/ARF expression and cell death in human lung cancer cell lines including SCLC cell lines. In our in vivo study, treatment of SLC36, combined with low dosage of adriamycin (1 mg/kg) can suppress the cancer incidence as well as progression in K-RasLA2 and K-Ras/DX2 double Tg model. These results indicate that DX2 can contribute to lung cancer progression and development, including SCLC, through inhibition of p14/ARF, and blocking of DX2-p14/ARF binding would be useful therapeutic strategy of human lung cancers including SCLC as well as NSCLC.

Citation Format: Ah Young Oh, Youn-Sang Jung, Su-Jin Lee, Jung Hyun Jo, Ho Young Chun, Bum-Joon Park. Blocking of p14/ARF and DX2 binding by novel small chemical can improve the chemo-sensitivity of small cell lung cancer and non-small cell lung carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4602. doi:10.1158/1538-7445.AM2014-4602

Loss of VHL promotes progerin expression, leading to impaired p14/ARF function and suppression of p53 activity

Renal cell carcinomas (RCCs) are frequently occurring genitourinary malignancies in the aged population. A morphological characteristic of RCCs is an irregular nuclear shape, which is used to index cancer grades. Other features of RCCs include the genetic inactivation of the von Hippel-Lindau gene, VHL, and p53 genetic-independent inactivation. An aberrant nuclear shape or p53 suppression has not yet been demonstrated. We examined the effect of progerin (an altered splicing product of the LMNA gene linked to Hutchinson Gilford progeria syndrome; HGPS) on the nuclear deformation of RCCs in comparison to that of HGPS cells. In this study, we showed that progerin was suppressed by pVHL and was responsible for nuclear irregularities as well as p53 inactivation. Thus, progerin suppression can ameliorate nuclear abnormalities and reactivate p53 in response to genotoxic addition. Furthermore, we found that progerin was a target of pVHL E3 ligase and suppressed p53 activity by p14/ARF inhibition. Our findings indicate that the elevated expression of progerin in RCCs results from the loss of pVHL and leads to p53 inactivation through p14/ARF suppression. Interestingly, we showed that progerin was expressed in human leukemia and primary cell lines, raising the possibility that the expression of this LMNA variant may be a common event in age-related cancer progression.

Diagnostic performance of 18F-FDG PET/CT, ultrasonography and MRI. Detection of axillary lymph node metastasis in breast cancer patients

The aim of this study was to evaluate the diagnostic abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography(PET/CT) compared with those of ultrasonography and magnetic resonance imaging (MRI) for axillary lymph node staging in breast cancer patients.

PATIENTS, METHODS

Preoperative 18F-FDG PET/non-contrast CT, ultrasonography and MRI were performed in 215 women with breast cancer. Axillary lymph node dissection was performed in all patients and the diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. ROC curves were compared to evaluate the diagnostic ability of several imaging modalities (i. e., ultrasonography, MRI and 18F-FDG PET/CT).

RESULTS

In total, 132 patients (61.4%) had axillary lymph node metastasis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the detection of axillary lymph node metastasis were 72.3%, 77.3%, 66.7%, 81.6%, 75.3% for ultrasonography, 67.5%, 78.0%, 65.9%, 79.2%, 74.0% for MRI, and 62.7%, 88.6%, 77.6%, 79.1%, 78.6% for 18F-FDG PET/CT, respectively. There was no significant difference in diagnostic ability among the imaging modalities (i.e., ultrasonography, MRI and 18F-FDG PET/CT). The diagnostic ability of 18F-FDG PET/CT was significantly improved by combination with MRI (p = 0.0002) or ultrasonography (p < 0.0001). The combination of 18F-FDG PET/CT with ultrasonography had a similar diagnostic ability to that of all three modalities combined (18F-FDG PET/CT+ultrasonography+MRI, p = 0.05).

CONCLUSION

The diagnostic performance of 18F-FDG PET/CT for detection of axillary node metastasis was not significantly different from that of ultrasonography or MRI in breast cancer patients. Combining 18F-FDG PET/CT with ultrasonography or MRI could improve the diagnostic performance compared to 18F-FDG PET/CT alone.

Elevated TRAF2/6 expression in Parkinson's disease is caused by the loss of Parkin E3 ligase activity

Parkinson's disease (PD) is the second leading neurodegenerative disease, and is known to be induced by environmental factors or genetic mutations. Among the verified genetic mutations of PD, Parkin, isolated from the PARK2 locus, shows an autosomal recessive inheritance pattern and is known to be an E3 ligase. However, the physiological target of Parkin and the molecular mechanism of Parkin-deficiency-induced PD have not been clearly demonstrated until now. It has recently been proposed that inflammation, suggesting as a causal factor for PD, is enhanced by Parkin deficiency. Thus, we examined the relationship between inflammation-related factors and Parkin. Here, we provide the evidence that Parkin suppresses inflammation and cytokine-induced cell death by promoting the proteasomal degradation of TRAF2/6 (TNF-α receptor-associated factor 2/6). Overexpression of Parkin can reduce the half-lives of TRAF2 and TRAF6, whereas si-Parkin can extend them. However, mutant Parkins did not alter the expression of TRAF2/6. Thus, loss of Parkin enhances sensitivity to TNF-α- or IL-1β-induced JNK activation and NF-κB activation. Indeed, si-Parkin-induced apoptosis is suppressed by the knockdown of TRAF6 or TRAF2. We also observed elevated expression levels of TRAF6 and a reduction of IκB in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced PD mouse model. Moreover, elevated expression levels or aggregation of TRAF6 were detected in approximately half of the human PD tissues (7/15 cases) and 2 cases, respectively. In addition, TRAF6 and Parkin expression levels show a reverse relationship in human PD tissues. Our results strongly suggest that the reduction of Parkin or overexpression of TRAF2/6 by chronic inflammation would be the reason for occurrence of PD.

Estrogen receptor α is a novel target of the Von Hippel-Lindau protein and is responsible for the proliferation of VHL-deficient cells under hypoxic conditions

The Von Hippel-Lindau gene (VHL) is frequently deleted or mutated in human renal cell carcinoma (RCC) at the early stage. According to the well-established theory, pVHL acts as a tumor suppressor through its E3 ligase activity, which targets hypoxia-inducing factor-1α (HIF-1α). However, the elevated expression of HIF-1α did not promote cell proliferation, indicating that there would be another target, which could promote cell proliferation at the early cancer stage of RCC. In this study, we show that estrogen receptor-α (ER-α) is a novel proteasomal degradation target of the pVHL E3 ligase. Indeed, the overexpression of VHL suppresses exo- and endogenous ER-α expression, whereas si-pVHL can increase ER-α expression. The negative regulation of pVHL on ER-α expression is achieved by its E3 ligase activity. Thus, pVHL can promote the ER-α ubiquitinylation. In addition, we revealed that ER-α and HIF-1α are competitive substrates of pVHL. Thus, under normal conditions, ER-α overexpression can increase the transcription factor activity of HIF-1α. Under the hypoxic condition, where HIF-1α is not a suitable target of pVHL, ER-α is more rapidly degraded by pVHL. However, in VHL-deficient cells, the expression of ER-α and HIF-1α is retained, so that the hypoxic condition did not suppress cell proliferation obviously compared with cells that are expressing pVHL. Thus, blocking of ER-α using its inhibitor could suppress the proliferation of VHL-deficient cells as effectively as hypoxia-induced growth suppression. Considering our results, blocking of ER-α signaling in VHL-deficient cancer cells would be beneficial for cancer suppression. Indeed, we showed the anti-proliferative effect of Faslodex in VHL-deficient cells.

Abstract B3: Induction of Smad4 in response to serum starvation promotes cell death through PUMA stabilization

Smad4 is an essential factor in TGF-β signaling and is also known as frequently mutated tumor suppressor gene in human pancreatic and colon cancer. However, considering the fact that TGF-β can contribute to cancer progression through transcriptional target genes such as Snail, MMPs, and EMT-related genes, loss of Smad4 in human cancer would be required for obtaining the TGF-β signaling independent advantage, which should be essential for cancer cell survival. Here we provide the evidence about novel role of Smad4, serum-deprivation-induced apoptosis. Elimination of serum can obviously increase the Smad4 expression and induces the cell death by p53-independent PUMA induction. Instead, Smad4 deficient cells show the resistance to serum starvation. Induced Smad4 suppresses the PAK1, which promotes the PUMA destabilization. We also found that siah-1 and pVHL are involved in PAK1 destabilization and PUMA stabilization. In fact, Smad4-expressed cancer tissues show the elevated expression of PAK1, also supprots our hypothesis that Smad4 induces PUMA-mediated cell death through PAK1 suppression. Our results strongly suggest that loss of Smad4 render the resistance to serum-deprivation-induced cell death, which is the TGF-β independent tumor suppressive role of Smad4.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr B3.

Abstract A50: Loss of pVHL inactivates p53 by permission of interaction between p14/ARF and progerin

Renal cell carcinoma (RCC) is a common primary renal malignancy in adults. The typical feature is the nuclear irregularity which is a basis for grading. Moreover, resistance to chemotherapy and irradiation (IR) is also one of the characters of RCC. p53 inactivation without genetic mutation and pVHL mutation in early stage are shown in RCC. However, it is still remained the question about the mechanism of the nuclear deformation and chemotherapy resistance. Here we proposed that the effect of progerin on RCC. Progerin elevated in RCC and the elimination of progerin could ameliorate the nuclear morphology. Moreover, knockdown of progerin could recover DNA damage sensitivity and p53 activation in RCC. Loss of pVHL induces elevated progerin expression, which inhibit p14/ARF by direct interaction to suppress p53 activity. Moreover, forced enhancement of progerin is found in human leukemia sample. In this study, we provide that the novel mechanism for p53 suppression in RCC and the importance of progerin in cancer progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A50.

Abstract A56: Tumor alarm gene FHIT activates tumor suppressive system by self-scarifying

Human fragile histidine triad (FHIT) is known to be a putative tumor suppressor gene because of frequent deletion and mutation in various kinds of human cancers, in particular, human lung cancer. However, its biological function as tumor suppressor gene, has not been demonstrated. In fact, there are conflict results on the role of FHIT. Oncogenic property of FHIT has been proposed such as overeactivation of ATR/CHK1 pathway in FHIT deficient cells, and low tumor incidence in FHIT-deficient mice. In contrast, tumor suppressive functions such as cell cycle inhibition and induction of apoptosis also proposed. Here we provide the evidences about unexpected working mechanism of FHIT as a tumor alarm gene. FHIT can awake the intracellular tumor suppressive system through reduction or deletion itself. FHIT reduction or deleted cells significantly increase the p21/WAF1 expression as well as p14/ARF-p53. It is achieved at posttranslation level and p53-dependent manner. So loss of FHIT can sequester the cell cycle in G1 phase. FHIT reduction can be achieved by oncogene activation and DNA damage. Thus, FHIT-deficient cells did not response to additional tumor risk and accumulation of additional genetic mutation is easily fixed in genome, which may contribute to tumor progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A56.

Antitumor effect of novel small chemical inhibitors of Snail-p53 binding in K-Ras-mutated cancer cells

p53 is frequently mutated by genetic alternation or suppressed by various kinds of cellular signaling pathways in human cancers. Recently, we have revealed that p53 is suppressed and eliminated from cells by direct binding with oncogenic K-Ras-induced Snail. On the basis of the fact, we generated specific inhibitors against p53-Snail binding (GN25 and GN29). These chemicals can induce p53 expression and functions in K-Ras-mutated cells. However, it does not show cytotoxic effect on normal cells or K-Ras-wild-type cells. Moreover, GN25 can selectively activate wild-type p53 in p53(WT/MT) cancer cells. But single allelic mt p53 containing cell line, Panc-1, does not respond to our chemical. In vivo xenograft test also supports the antitumor effect of GN25 in K-Ras-mutated cell lines. These results suggest that our compounds are strong candidate for anticancer drug against K-Ras-initiated human cancers including pancreatic and lung cancers.

Role of CK1 in GSK3beta-mediated phosphorylation and degradation of snail

The epithelial to mesenchymal transition (EMT) that occurs during embryonic development has begun to attract attention as a potential mechanism for tumor cell metastasis. Snail is a well-known Zn-finger transcription factor that promotes EMT by repressing E-cadherin expression. It is known that Snail is phosphorylated by GSK3beta and degraded by beta-TrCP-mediated ubiquitination. Here we described another protein kinase, CK1, whose phosphorylation of Snail is required for the subsequent GSK3beta phosphorylation. Specific inhibition or depletion of CK1varepsilon inhibits the phosphorylation and degradation of Snail and promotes cell migration, suggesting a central role of CK1varepsilon in the EMT process. Furthermore, our study uncovered distinct roles and steps of Snail phosphorylation by CK1varepsilon and GSK3beta. Taken together, we identified CK1varepsilon as a new component of the Snail-mediated EMT process, providing insight into the mechanism of human cancer metastasis.

Isolation of a chemical inhibitor against K-Ras-induced p53 suppression through natural compound screening

The strong tumor suppressor p53 shows loss of function in large portion of human cancer. In addition to genetic mutation, biological function of p53 is suppressed by signaling distortion or elevated expression of p53 inhibitors (such as overexpression of MDM2 or deletion of p14/ARF). In this study, we demonstrate that K-Ras, a frequently altered oncogene in human cancers including pancreatic cancer (about 80%), colon cancer (45%) and lung cancer (45%), suppresses p53. Based on this fact, we perform Western blot analysis-based chemical screening to isolate a K-Ras-specific activator of p53. From 117 kinds of chemicals (34 kinds of natural compounds that are obtained from herbal plants, 53 kinds of flavonoid, and 31 kinds of phenolic compounds), we find that quercetin works as an activator of p53 in K-Ras mutated cells but not in wild-type cells. Treatment with quercetin can induce p53 target genes such as PUMA and p21. These results suggest that although quercetin has limitations for use as a therapeutic drug due to its broad effects, specific function of it on K-Ras-p53 may be useful for K-Ras-induced cancer prevention and therapy through further development.

Pharmacokinetics of oltipraz in diabetic rats with liver cirrhosis

BACKGROUND AND PURPOSE

The incidence of diabetes mellitus is increased in patients with liver cirrhosis. Oltipraz is currently in trials to treat patients with liver fibrosis and cirrhosis induced by chronic hepatitis types B and C and is primarily metabolized via hepatic cytochrome P450 isozymes CYP1A1/2, 2B1/2, 2C11, 2D1 and 3A1/2 in rats. We have studied the influence of diabetes mellitus on pharmacokinetics of oltipraz and on expression of hepatic, CYP1A, 2B1/2, 2C11, 2D and 3A in rats with experimental liver cirrhosis.

EXPERIMENTAL APPROACH

Oltipraz was given intravenously (10 mg x kg(-1)) or orally (30 mg x kg(-1)) to rats with liver cirrhosis induced by N-dimethylnitrosamine (LC rats) or with diabetes, induced by streptozotocin (DM rats) or to rats with both liver cirrhosis and diabetes (LCD rats) and to control rats, and pharmacokinetic variables measured. Protein expression of hepatic CYP1A, 2B1/2, 2C11, 2D and 3A was measured using Western blot analysis.

KEY RESULTS

After i.v. or p.o. administration of oltipraz to LC and DM rats, the AUC was significantly greater and smaller, respectively, than that in control rats. In LCD rats, the AUC was that of LC and DM rats (partially restored towards control rats). Compared with control rats, the protein expression of hepatic CYP1A increased, that of CYP2C11 and 3A decreased, but that of CYP2B1/2 and 2D was not altered in LCD rats.

CONCLUSIONS AND IMPLICATIONS

In rats with diabetes and liver cirrhosis, the AUC of oltipraz was partially restored towards that of control rats.

Antimicrobial effect of water-soluble muscadine seed extracts on Escherichia coli O157:H7

Water-soluble extracts were prepared from purple (cultivar Ison) and bronze (cultivar Carlos) muscadine seeds with or without heating. The Ison extracts had strong antimicrobial activity against a cocktail of three strains of Escherichia coli O157: H7. This extract had higher acidity (pH 3.39 to 3.43), total phenolics (2.21 to 3.49 mg/ml), tartaric acid (5.6 to 10.7 mg/ml), tannic acid (5.7 to 8.1 mg/ml), and gallic acid (0.33 to 0.59 mg/ml) than did the Carlos extracts. Heat treatment on both extracts increased antimicrobial activity, possibly because of increased acidity, tartaric acid, total phenolics, and individual phenolics. Heating of Ison extracts increased ellagic acid up to 83%. Up to 10.7 mg/ml tartaric acid alone was not as effective against E. coli O157:H7 as were water-soluble seed extracts. This finding suggests the involvement of other factors, such as tannic and gallic acids, in inactivation of this pathogen. Water-soluble muscadine seed extracts may be useful for incorporation into juice and other beverage products as natural preservatives.

Cyclooxygenase-2 expression in human thyroid disease

OBJECTIVES

Cyclooxygenase (COX)-2, which is the inducible form of the COX enzyme for prostaglandin synthesis and a key mediator of epithelial cell growth, has been shown to be up-regulated in gastrointestinal cancers. Additionally, regular intake of other non-steroidal anti-inflammatory drugs (NSAID) is known to decrease the incidence of these cancers. Therefore, the goals of the present study were to determine the possible involvement of COX-2 in human thyroid diseases.

METHODS

We used immunohistochemical staining and Western blot analysis to characterize the expression of COX-2 proteins in thyroid tissues from 64 patients with thyroiditis, benign tumors, and malignant tumors with or without metastasis. Immunoreactivity scores were calculated by multiplication of the determined grades.

RESULTS

COX-2 proteins were not expressed in normal thyroid tissues. However, each type of tumor tissue showed intense bands of COX-2 protein expression in Western blot analyses, and the immunoreactivity scores were 7.67+/-1.17 (SD) for thyroiditis, 7.87+/-0.9 for benign tumors, 7.53+/-1.53 for follicular cancer, 7.63+/-1.11 for papillary cancer without metastasis, and 7.17+/-1.55 for papillary cancer with metastasis. No significant differences were found in the levels of COX-2 expression between different tumor tissue types.

CONCLUSION

No significant correlations were observed between clinical and/or pathological characteristics of thyroid tumors and the intensity of COX-2 protein expression. In addition, we found no difference in COX-2 protein expression between thyroiditis and thyroid tumors. Thus, up-regulation of COX-2 protein synthesis in human thyroid diseases does not appear to be of clinical significance.

[Synthesis of reactivators of phosphorylated acetylcholinesterase of bis-pyridiniumdialdoxime type with a 3-oxapentane connecting chain and their testing in vitro on a model of the enzyme inhibited by chlorpyrifos and methylchlorpyrifos]

Insecticides (e.g., parathion, chlorpyrifos, methylchlorpyrifos) and nerve agents (e.g.. soman, sarin, tabun, VX) belong to the group of organophosphates. They are able to irreversibly inhibit the enzyme acetylcholinesterase (AChE). Three new reactivators with a 3-oxapentane connecting chain were prepared. The ability of the new compounds to reactivate AChE inhibited by pesticides was tested in vitro and compared to known oxime 10(-3) M which is unfortunately not applicable to in vivo experiments. All tested compounds are practically ineffective for methylchlorpyrifos-inhibited AChE at the physiological concentration (10(-5) M). On the other hand, the known reactivators surpass new substances in the case of chlorpyrifos-inhibited AChE at both concentrations.

Inhibitory effect of select nitrocompounds on growth and survivability of Listeria monocytogenes in vitro

We report the effects of 2-nitro-1-propanol (2NPOH), 2-nitroethanol (2NEOH), and nitroethane (NE) on growth and survivability of Listeria monocytogenes. In all cases, inhibition was greatest with 2NPOH and least with NE. For example, specific growth rates of L. monocytogenes strain 18 declined (P < 0.05) 76, 60, and 29% from controls during aerobic culture at 37 degrees C in brain heart infusion broth containing 10 mM 2NPOH, 2NEOH, or NE, respectively. Mean specific growth rate for the controls incubated likewise without added nitrocompound was 0.62 +/- 0.02 h(-1). Specific growth rates of L. monocytogenes Scott A decreased (P < 0.05) 67, 45, and 11%, respectively, from controls (0.67 +/- 0.02 h(-1)) when cultured similarly. Specific growth rates for L. monocytogenes strain 18 incubated similarly except at 30 degrees C were reduced (P < 0.05) 76, 60, and 30%, respectively, and were reduced (P < 0.05) 78, 23, and 23% during anaerobic culture at 30 degrees C in brain heart infusion broth containing 15 mM 2NPOH, 2NEOH, or NE (control rates ranged from 0.37 +/- 0.07 to 0.74 +/- 0.05 h(-1)). Survivability of L. monocytogenes strain 18 was reduced (P < 0.05) during aerobic storage (4 months at 4 degrees C) in brain heart infusion broth containing 2NPOH or 2NEOH (by 7.8 and 1.9 log units, respectively) but not NE. The inhibitory effect of 2NPOH was approximately 20% greater during growth at pH 7.0 than at pH 5.6 or 8.0. These results demonstrate the differential inhibitory activity of 2NPOH, 2NEOH, and NE against L. monocytogenes in vitro.

Novel preharvest strategies involving the use of experimental chlorate preparations and nitro-based compounds to prevent colonization of food-producing animals by foodborne pathogens

Foodborne diseases caused by enterohemorrhagic Escherichia coli, Salmonella, and Campylobacter species are of public health and economic significance. Shedding of these pathogens during production and slaughter are risks for contamination of products for human consumption. Consequently, strategies are sought to prevent or reduce the carriage of these pathogens in food animals before slaughter. Experimental products containing chlorate salts have been proven efficacious in reducing concentrations of E. coli and Salmonella Typhimurium in the gut of cattle, sheep, swine, and poultry when administered as feed or water additives. Mechanistically, chlorate selectively targets bacteria expressing respiratory nitrate reductase activity, such as most members of the family Enterobacteriaceae, as this enzyme catalyzes the reduction of chlorate to lethal chlorite. Most beneficial gut bacteria lack respiratory nitrate reductase activity, and thus the technology appears compatible with many bacteria exhibiting competitive exclusion capabilities. More recently, select nitrocompounds have been investigated as potential feed additives, and although these nitrocompounds significantly reduce pathogens on their own, evidence indicates that they may most effectively be used to complement the bactericidal activity of chlorate. A particularly attractive aspect of the nitrocompound technology is that, as potent inhibitors of ruminal methanogenesis, they may allow producers the opportunity to recoup costs associated with their use. At present, neither chlorate nor the nitrocompounds have been approved as feed additives by the US Food and Drug Administration, and consequently they are not yet available for commercial use.