Impact of quality of life on mortality risk in patients with esophageal cancer: a systematic review and meta-analysis

This systematic review and meta-analysis investigated the impact of quality of life (QoL) on mortality risk in patients with esophageal cancer. A literature search was conducted using the CINAHL, PubMed/MEDLINE, and Scopus databases for articles published from inception to December 2022. Observational studies that examined the association between QoL and mortality risk in patients with esophageal cancer were included. Subgroup analyses were performed for time points of QoL assessment and for types of treatment. Seven studies were included in the final analysis. Overall, global QoL was significantly associated with mortality risk (hazard ratio 1.02, 95% confidence interval 1.01-1.04; p < 0.00004). Among the QoL subscales of QoL, physical, emotional, role, cognitive, and social QoL were significantly associated with mortality risk. A subgroup analysis by timepoints of QoL assessment demonstrated that pre- and posttreatment global and physical, pretreatment role, and posttreatment cognitive QoL were significantly associated with mortality risk. Moreover, another subgroup analysis by types of treatment demonstrated that the role QoL in patients with surgery, and the global, physical, role, and social QoL in those with other treatments were significantly associated with mortality risk. These findings indicate that the assessment of QoL in patients with esophageal cancer before and after treatment not only provides information on patients' condition at the time of treatment but may also serve as an outcome for predicting life expectancy. Therefore, it is important to conduct regular QoL assessments and take a proactive approach to improve QoL based on the results of these assessments.

Effects of taxane-induced peripheral neuropathy on hand dexterity impairment: evaluation of quantitative and subjective assessments

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) commonly involves hand dexterity impairment. However, the factors affecting hand dexterity impairment are unknown and there is currently no established treatment. The purpose of the current study was to clarify factors influencing hand dexterity impairment in taxane-induced peripheral neuropathy using subjective and objective assessments.

METHODS

We assessed patient characteristics, treatment-related factors, subjective symptoms of CIPN (Patient Neurotoxicity Questionnaire [PNQ]), psychological symptoms, and upper limb dysfunction (Quick Disabilities of the Arm, Shoulder and Hand [Quick DASH]). Quantitative assessments were pinch strength, sensory threshold, hand dexterity impairment, and grip force control. Multiple regression analysis was performed using hand dexterity impairment as the dependent variable and age and PNQ, Quick DASH, and control of grip force as independent variables.

RESULTS

Forty-three breast cancer patients were included in the analysis. Hand dexterity impairment in taxane-induced peripheral neuropathy patients was significantly correlated with age, grip force control, and PNQ sensory scores (p < 0.008). Multiple regression analysis demonstrated that PNQ sensory scores and grip force control were significantly associated with hand dexterity impairment (p < 0.01).

CONCLUSION

Subjective symptoms (numbness and pain) and grip force control contributed to impaired hand dexterity in taxane-induced peripheral neuropathy.

Pretreatment quality of life and survival in patients with lung cancer: a systematic review and meta-analysis

BACKGROUND

Although many studies have explored the correlation between quality of life and survival, none have reported this relationship for specific cancers assessed at distinct time points. This meta-analysis aimed to investigate the impact of pretreatment Global Quality of Life (QOL) and functioning QOL, including physical, social, role, emotional, and cognitive QOLs, on mortality risk in patients with lung cancer.

METHODS

A literature search was conducted across the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and PubMed databases for articles published between their inception and December 2022. Subsequently, 11 studies were selected based on predefined eligibility criteria to investigate the relationship between pretreatment QOLs and mortality risk in patients with lung cancer.

RESULTS

Pretreatment global, physical, social, role, and emotional QOLs were significantly associated with mortality risk as follows: Global QOL (hazard ratio [HR] = 1.08 95% confidence interval [CI] = 1.03-1.13); Physical QOL (HR = 1.04 95% CI = 1.02-1.05); Social QOL (HR = 1.02 95% CI = 1.01-1.03; Role QOL (HR = 1.01 95% CI = 1.01-1.02); Emotional QOL (HR = 1.01 95% CI = 1.00-1.03).

CONCLUSIONS

These findings underscore the importance of early QOL assessment after diagnosis as well as early provision of physical, social, and psychological support accommodating each patient's demands.

TRIAL REGISTRATION

The International Prospective Register of Systematic Reviews registration number CRD42023398206, Registered on February 20, 2023.

Association between quality of life and mortality risk in patients with breast cancer: a systematic review and meta-analysis

BACKGROUND

Patients with breast cancer present with various problems that have an adverse effect on the quality of life (QOL). However, the association between the QOL and mortality among patients with breast cancer remains controversial. Therefore, this systematic review and meta-analysis aimed to determine whether QOL impacts prognosis in patients with breast cancer.

METHODS

The databases of CINAHL, Scopus, and PubMed databases were searched to retrieve observational studies that assessed the QOL and mortality risk in patients with breast cancer published before December 2022.

RESULTS

Among the 119,061 articles retrieved, six observational studies were included in the meta-analysis. Physical QOL (hazard ratio [HR]: 1.04, 95% confidence interval [CI]: 1.01-1.07, p = 0.003), emotional QOL (HR: 1.01, 95% CI: 1.00-1.03, p = 0.05), and role QOL (HR: 1.01, 95% CI: 1.00-1.01, p = 0.007) showed significant associations with mortality risk. In contrast, global QOL, cognitive QOL, and social QOL showed no associations with mortality risk. Subgroup analysis performed according to treatment time points revealed that the post-treatment physical QOL was associated with mortality risk.

CONCLUSIONS

Physical QOL, emotional QOL, and role QOL are associated with mortality risk in patients with breast cancer. Furthermore, post-treatment physical QOL showed a more significant association with prolonged survival than pre-treatment physical QOL.

Factors Influencing Life Space Mobility in Cancer Survivors Following Hematopoietic Stem Cell Transplantation - Physical Function, Depression, Fatigue, Neighborhood Walkability, and Employment Status

BACKGROUND/OBJECTIVE

The level of physical activity in the daily lives of cancer survivors following hematopoietic stem cell transplantation (HSCT) is crucial for maintaining their physical and mental health. Considering that life space mobility (LSM) may limit physical activity, maintaining and expanding LSM is particularly essential for post-HSCT survivors. This study aimed to identify factors influencing LSM in post-HSCT survivors.

METHODS

Thirty cancer survivors after HSCT (14 women, mean age 52.0 ± 12.3 years, 196-3017 days post-HSCT) were included in this cross-sectional study. The assessment encompassed patient characteristics, employment status, life space (Life Space Assessment; LSA), physical function (handgrip strength, isometric knee extension strength, 5 chair standing test, walking speed), depression (Self-rating Depression Scale; SDS), fatigue (Cancer Fatigue Scale), and neighborhood walkability (Walk Score®). The association between LSA and each factor was compared by correlation analysis. Subsequently, multiple regression analysis was conducted, with LSA as the dependent variable and independent variables being outcome measures exhibiting a significant correlation with LSA.

RESULTS

Variables significantly correlated with LSA included SDS (r =-0.65, p < .01), employment status (r=-0.60, p < .01), handgrip strength (r = 0.43, p = .02), and isometric knee extension strength (r = 0.40, p = .03). Results of multiple regression analysis show that SDS (β = -0.53, p < .01), employment status (β = 0.48, p < .01), and isometric knee extension strength (β = 0.27, p = .02) were significantly associated with LSA (R2 = 0.74).

CONCLUSION

Depression, employment status, and isometric knee extension strength were identified as factors related to LSM in post-HSCT survivors.

TIFAB regulates the TIFA-TRAF6 signaling pathway involved in innate immunity by forming a heterodimer complex with TIFA

Nuclear factor κB (NF-κB) is activated by various inflammatory and infectious molecules and is involved in immune responses. It has been elucidated that ADP-β-D-manno-heptose (ADP-Hep), a metabolite in gram-negative bacteria, activates NF-κB through alpha-kinase 1 (ALPK1)-TIFA-TRAF6 signaling. ADP-Hep stimulates the kinase activity of ALPK1 for TIFA phosphorylation. Complex formation between phosphorylation-dependent TIFA oligomer and TRAF6 promotes the polyubiquitination of TRAF6 for NF-κB activation. TIFAB, a TIFA homolog lacking a phosphorylation site and a TRAF6 binding motif, is a negative regulator of TIFA-TRAF6 signaling and is implicated in myeloid diseases. TIFAB is indicated to regulate TIFA-TRAF6 signaling through interactions with TIFA and TRAF6; however, little is known about its biological function. We demonstrated that TIFAB forms a complex not with the TIFA dimer, an intrinsic form of TIFA involved in NF-κB activation, but with monomeric TIFA. The structural analysis of the TIFA/TIFAB complex and the biochemical and cell-based analyses showed that TIFAB forms a stable heterodimer with TIFA, inhibits TIFA dimer formation, and suppresses TIFA-TRAF6 signaling. The resultant TIFA/TIFAB complex is a "pseudo-TIFA dimer" lacking the phosphorylation site and TRAF6 binding motif in TIFAB and cannot form the orderly structure as proposed for the phosphorylated TIFA oligomer involved in NF-κB activation. This study elucidated the molecular and structural basis for the regulation of TIFA-TRAF6 signaling by TIFAB.

Effects of Group Exercise Intervention on Quality of Life and Physical Parameters in Patients with Childhood Cancer: A Systematic Review

BACKGROUND

Although the survival rates of childhood cancer are increasing, children diagnosed as having cancer experience psychological and physical problems and a declining quality of life (QOL).

METHODS

A systematic review of PubMed databases was conducted up to September 2023 to identify studies reporting the effects of group exercise intervention in children with cancer. The inclusion criteria were pre-specified, including children aged ≤19 years old who received group exercise intervention and interventional studies written in English. Studies involving non-exercise intervention or non-group intervention were excluded.

RESULTS

Five studies were included in the present review. In three studies, QOL and physical parameters were improved after group exercise intervention, and in two studies, only physical parameters were improved. Improvements in QOL were achieved through psychosocial variables, improved scores of subscales of pain and hurt, nausea, and procedure-related anxiety, and reduced cancer-related fatigue. All studies had high numbers of participants who completed the intervention. However, all studies showed a high risk of bias regarding the selection of the reported results, and most studies showed a high risk of bias regarding deviations from the intended intervention and outcome measurement.

CONCLUSION

The reviewed studies showed that group exercise intervention for children with cancer could improve their QOL and/or physical parameters.

Structural Characterization of TRAF6 N-Terminal for Therapeutic Uses and Computational Studies on New Derivatives

Tumor necrosis factor receptor-associated factors (TRAFs) are a protein family with a wide variety of roles and binding partners. Among them, TRAF6, a ubiquitin ligase, possesses unique receptor binding specificity and shows diverse functions in immune system regulation, cellular signaling, central nervous system, and tumor formation. TRAF6 consists of an N-terminal Really Interesting New Gene (RING) domain, multiple zinc fingers, and a C-terminal TRAF domain. TRAF6 is an important therapeutic target for various disorders and structural studies of this protein are crucial for the development of next-generation therapeutics. Here, we presented a TRAF6 N-terminal structure determined at the Turkish light source "Turkish DeLight" to be 3.2 Å resolution at cryogenic temperature (PDB ID: 8HZ2). This structure offers insight into the domain organization and zinc-binding, which are critical for protein function. Since the RING domain and the zinc fingers are key targets for TRAF6 therapeutics, structural insights are crucial for future research. Separately, we rationally designed numerous new compounds and performed molecular docking studies using this template (PDB ID:8HZ2). According to the results, 10 new compounds formed key interactions with essential residues and zinc ion in the N-terminal region of TRAF6. Molecular dynamic (MD) simulations were performed for 300 ns to evaluate the stability of three docked complexes (compounds 256, 322, and 489). Compounds 256 and 489 was found to possess favorable bindings with TRAF6. These new compounds also showed moderate to good pharmacokinetic profiles, making them potential future drug candidates as TRAF6 inhibitors.

Recent Findings in Physical Exercise for Cancer Survivors

In recent years, the number of cancer survivors has been increasing each year due to advances in the early diagnosis and treatment of cancer. Cancer survivors present a variety of physical and psychological complications due to cancer and its treatment. Physical exercise is an effective nonpharmacological treatment for complications in cancer survivors. Furthermore, recent evidence has shown that physical exercise improves the prognosis of cancer survivors. The benefits of physical exercise have been widely reported, and guidelines for physical exercise for cancer survivors have been published. These guidelines recommend that cancer survivors engage in moderate- or vigorous-intensity aerobic exercises and/or resistance training. However, many cancer survivors have a poor commitment to physical exercise. In the future, it is necessary to promote physical exercise among cancer survivors through outpatient rehabilitation and community support.

Neurological Outcomes of Chemotherapy-Induced Peripheral Neuropathy in Patients With Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aimed to determine whether chemotherapy-induced peripheral neuropathy (CIPN) affects the risk of falls and physical function in patients with cancer.

METHODS

A literature search was conducted in the CINAHL, Scopus, and PubMed databases for articles published from January 1950 to April 2022. Seven review authors retrieved studies using predetermined eligibility criteria, extracted the data, and evaluated the quality.

RESULTS

Nine studies were included in the analysis. Patients with CIPN had a significantly higher risk of falls than those without CIPN (risk ratio = 1.38, 95% confidence interval [CI] =1.18-1.62). Patients with CIPN had lower grip strength (standardized mean difference [SMD] =-0.42, 95% CIs = -0.70 to -0.14, P = .003), longer chair stand time (SMD = 0.56, 95% CIs = -0.01 to 1.17, P = .05), worse timed up and go test time (SMD = 0.79, 95% CIs = 0.41 to 1.17, P < .0001), and lower mean Fullerton Advanced Balance scale score (SMD = -0.81, 95% CIs = -1.27 to -0.36, P = .005) than patients without CIPN. There were no significant differences in gait speed (P = .38) or Activities-specific Balance Confidence Scale score (P = .09) between patients with and without CIPN.

CONCLUSIONS

This systematic review and meta-analysis demonstrated that patients with CIPN are prone to falls and impaired balance function and muscle strength.

Dysfunctional Sars-CoV-2-M protein-specific cytotoxic T lymphocytes in patients recovering from severe COVID-19

Although the importance of virus-specific cytotoxic T lymphocytes (CTL) in virus clearance is evident in COVID-19, the characteristics of virus-specific CTLs related to disease severity have not been fully explored. Here we show that the phenotype of virus-specific CTLs against immunoprevalent epitopes in COVID-19 convalescents might differ according to the course of the disease. We establish a cellular screening method that uses artificial antigen presenting cells, expressing HLA-A^*24:02, the costimulatory molecule 4-1BBL, SARS-CoV-2 structural proteins S, M, and N and non-structural proteins ORF3a and nsp6/ORF1a. The screen implicates SARS-CoV-2 M protein as a frequent target of IFNγ secreting CD8⁺ T cells, and identifies M_198-206 as an immunoprevalent epitope in our cohort of HLA-A^*24:02 positive convalescent COVID-19 patients recovering from mild, moderate and severe disease. Further exploration of M_198-206-specific CD8⁺ T cells with single cell RNA sequencing reveals public TCRs in virus-specific CD8⁺ T cells, and shows an exhausted phenotype with less differentiated status in cells from the severe group compared to cells from the moderate group. In summary, this study describes a method to identify T cell epitopes, indicate that dysfunction of virus-specific CTLs might be an important determinant of clinical outcomes.

The effect of home-based preoperative pulmonary rehabilitation before lung resection: A retrospective cohort study

OBJECTIVES

This study aimed to assess the effect of home-based preoperative pulmonary rehabilitation (HBPPR) on the incidence of postoperative complications, length of stay (LOS), and duration of intercostal catheterization in non-small cell lung cancer (NSCLC) patients who underwent lung resection.

MATERIALS AND METHODS

In this retrospective cohort study, 144 patients who underwent lung resection were recruited, 51 of whom received HBPPR, comprising respiratory muscle training and was supervised (for patients undergoing it for the first time). Patients continued these programs for 2-4 weeks during the preoperative waiting period, in their homes. Data on postoperative complications graded according to the Clavien-Dindo classification, LOS, and intercostal catheterization duration were collected from medical records. These outcomes were compared between the HBPPR and non-HBPPR groups using Fisher's exact test and Wilcoxon rank sum test, after 1:1 propensity score matching to avoid selection bias.

RESULTS

Forty-nine matched pairs were extracted using propensity score matching. HBPPR reduced the onset of postoperative complications (p = 0.04), with the relative ratio (RR) for Clavien-Dindo Class I postoperative complications showing a significant difference (RR 0.55, 95% CI 0.30-1.02; p = 0.05), whereas RRs for the other Clavien-Dindo classes were not statistically significant. There was no significant difference in LOS or the duration of intercostal catheterization.

CONCLUSION

HBPPR reduced the incidence of Clavien-Dindo Class I postoperative complications after lung resection. Implementing HBPPR practices in a clinical setting would benefit patients unable to receive supervised preoperative pulmonary rehabilitation due to access barriers, time, and financial constraints.

N-(4-Hydroxyphenyl) Retinamide Suppresses SARS-CoV-2 Spike Protein-Mediated Cell-Cell Fusion by a Dihydroceramide Δ4-Desaturase 1-Independent Mechanism

The membrane fusion between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and host cells is essential for the initial step of infection; therefore, the host cell membrane components, including sphingolipids, influence the viral infection. We assessed several inhibitors of the enzymes pertaining to sphingolipid metabolism, against SARS-CoV-2 spike protein (S)-mediated cell-cell fusion and viral infection. N-(4-Hydroxyphenyl) retinamide (4-HPR), an inhibitor of dihydroceramide Δ4-desaturase 1 (DES1), suppressed cell-cell fusion and viral infection. The analysis of sphingolipid levels revealed that the inhibition efficiencies of cell-cell fusion and viral infection in 4-HPR-treated cells were consistent with an increased ratio of saturated sphinganine-based lipids to total sphingolipids. We investigated the relationship of DES1 with the inhibition efficiencies of cell-cell fusion. The changes in the sphingolipid profile induced by 4-HPR were mitigated by the supplementation with exogenous cell-permeative ceramide; however, the reduced cell-cell fusion could not be reversed. The efficiency of cell-cell fusion in DES1 knockout (KO) cells was at a level comparable to that in wild-type (WT) cells; however, the ratio of saturated sphinganine-based lipids to the total sphingolipids was higher in DES1 KO cells than in WT cells. 4-HPR reduced cell membrane fluidity without any significant effects on the expression or localization of angiotensin-converting enzyme 2, the SARS-CoV-2 receptor. Therefore, 4-HPR suppresses SARS-CoV-2 S-mediated membrane fusion through a DES1-independent mechanism, and this decrease in membrane fluidity induced by 4-HPR could be the major cause for the inhibition of SARS-CoV-2 infection. IMPORTANCE Sphingolipids could play an important role in SARS-CoV-2 S-mediated membrane fusion with host cells. We studied the cell-cell fusion using SARS-CoV-2 S-expressing cells and sphingolipid-manipulated target cells, with an inhibitor of the sphingolipid metabolism. 4-HPR (also known as fenretinide) is an inhibitor of DES1, and it exhibits antitumor activity and suppresses cell-cell fusion and viral infection. 4-HPR suppresses membrane fusion through a decrease in membrane fluidity, which could possibly be the cause for the inhibition of SARS-CoV-2 infection. There is accumulating clinical data on the safety of 4-HPR. Therefore, it could be a potential candidate drug against COVID-19.

Impact of Preoperative Social Frailty on Overall Survival and Cancer-Specific Survival among Older Patients with Gastrointestinal Cancer

OBJECTIVES

Frailty is a multidimensional syndrome. However, typical frailty scales used in oncology clinics assess physical impairment and/or malnutrition but do not consider the social domain. Our study aimed to clarify the relationship between preoperative social frailty and overall survival (OS) and cancer-specific survival (CSS) among older patients with gastrointestinal cancer.

DESIGN

This was a prospective cohort study.

SETTING AND PARTICIPANTS

This single-center study recruited 195 patients with gastrointestinal cancer scheduled for curative surgery and aged >60 years.

METHODS

The outcomes considered were the OS and CSS of surgery. Primary associated factors included frailty defined as a Geriatric 8 score ≤14; social frailty defined as 2 or more of the following-going out less frequently, rarely visiting friends, feeling unhelpful to friends or family, living alone, and not talking with someone daily, and combinations therein [no frailty without social frailty (-/-), frailty without social frailty (+/-), no frailty with social frailty (-/+), and frailty with social frailty (+/+)]. We used the Cox proportional hazards model and the Fine and Gray proportional subdistribution hazard model adjusting for confounding factors.

RESULTS

Of the 195 patients, 181 (mean age, 72.0 years) were included for analysis. The median follow-up time was 994 days. Social frailty (hazard ratio 3.10) and their combinations [6.35; frailty with social frailty (+/+) vs no frailty without social frailty (-/-)] were significant predictors of OS. Social frailty (subdistribution hazard ratio 3.23) and their combinations (7.57) were significant predictors of CSS.

CONCLUSIONS AND IMPLICATIONS

Preoperative social frailty is a predictor of OS and CSS in older patients with gastrointestinal cancer. Screening for social frailty, frailty, and their combinations in older patients with cancer is important.

Comparison between quantitative and subjective assessments of chemotherapy-induced peripheral neuropathy in cancer patients: A prospective cohort study

OBJECTIVE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event experienced by cancer patients. In general, CIPN is evaluated subjectively based on patient self-assessment or clinician-reported scales; evidence supporting the utility and validity of quantitative sensory tests (QST) is lacking in this patient population. The aim of this study was to objectively assess CIPN of lower extremities by QSTs, and to evaluate the concordance between QSTs and subjective assessments.

METHODS

In this prospective cohort study, outpatients with cancer receiving chemotherapy were recruited at a single university hospital. We assessed CIPN at the lower extremities at baseline and three months after baseline. The QSTs were performed by applying a monofilament and a tuning fork to determine touch and vibration thresholds, respectively, at the affected site. Subjective assessments were performed based on the visual analog scale (VAS) and the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) toxicity grade. Kappa coefficients were calculated to evaluate the concordance between QSTs and subjective assessments.

RESULTS

After exclusion and drop-outs during follow-up, nineteen patients were included in the analysis. The prevalence of patients with abnormal sensation was 37% based on QSTs, 32% based on the VAS, and 14% based on CTCAE grading, respectively. Kappa coefficients were 0.32 between QSTs and VAS, and 0.28 between QSTs and CTCAE.

CONCLUSIONS

The concordance rates between quantitative and subjective assessments were low. CIPN should be assessed using both quantitative and subjective assessments.

The Antimalarial Compound Atovaquone Inhibits Zika and Dengue Virus Infection by Blocking E Protein-Mediated Membrane Fusion

Flaviviruses bear class II fusion proteins as their envelope (E) proteins. Here, we describe the development of an in vitro quantitative mosquito-cell-based membrane-fusion assay for the E protein using dual split proteins (DSPs). The assay does not involve the use of live viruses and allows the analysis of a membrane-fusion step independent of other events in the viral lifecycle, such as endocytosis. The progress of membrane fusion can be monitored continuously by measuring the activities of Renilla luciferase derived from the reassociation of DSPs during cell fusion. We optimized the assay to screen an FDA-approved drug library for a potential membrane fusion inhibitor using the E protein of Zika virus. Screening results identified atovaquone, which was previously described as an antimalarial agent. Atovaquone potently blocked the in vitro Zika virus infection of mammalian cells with an IC₉₀ of 2.1 µM. Furthermore, four distinct serotypes of dengue virus were also inhibited by atovaquone with IC₉₀ values of 1.6–2.5 µM, which is a range below the average blood concentration of atovaquone after its oral administration in humans. These findings make atovaquone a likely candidate drug to treat illnesses caused by Zika as well as dengue viruses. Additionally, the DSP assay is useful to study the mechanism of membrane fusion in Flaviviruses.

The Anticoagulant Nafamostat Potently Inhibits SARS-CoV-2 S Protein-Mediated Fusion in a Cell Fusion Assay System and Viral Infection In Vitro in a Cell-Type-Dependent Manner

Although infection by SARS-CoV-2, the causative agent of coronavirus pneumonia disease (COVID-19), is spreading rapidly worldwide, no drug has been shown to be sufficiently effective for treating COVID-19. We previously found that nafamostat mesylate, an existing drug used for disseminated intravascular coagulation (DIC), effectively blocked Middle East respiratory syndrome coronavirus (MERS-CoV) S protein-mediated cell fusion by targeting transmembrane serine protease 2 (TMPRSS2), and inhibited MERS-CoV infection of human lung epithelium-derived Calu-3 cells. Here we established a quantitative fusion assay dependent on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S protein, angiotensin I converting enzyme 2 (ACE2) and TMPRSS2, and found that nafamostat mesylate potently inhibited the fusion while camostat mesylate was about 10-fold less active. Furthermore, nafamostat mesylate blocked SARS-CoV-2 infection of Calu-3 cells with an effective concentration (EC)50 around 10 nM, which is below its average blood concentration after intravenous administration through continuous infusion. On the other hand, a significantly higher dose (EC50 around 30 mM) was required for VeroE6/TMPRSS2 cells, where the TMPRSS2-independent but cathepsin-dependent endosomal infection pathway likely predominates. Together, our study shows that nafamostat mesylate potently inhibits SARS-CoV-2 S protein-mediated fusion in a cell fusion assay system and also inhibits SARS-CoV-2 infection in vitro in a cell-type-dependent manner. These findings, together with accumulated clinical data regarding nafamostat's safety, make it a likely candidate drug to treat COVID-19.

Association between preoperative sleep disturbance and low muscle mass in patients with gastrointestinal cancer

[Purpose] Low muscle mass and sleep disturbance are common among geriatric patients with cancer. In patients with gastrointestinal cancer, low muscle mass is considered an indicator of poor prognosis. In the recent years, sleep disturbance has attracted much attention as a factor for low muscle mass among community-dwelling elderly individuals; however, such associations are unclear in patients with cancer. The present study investigated the relationship between preoperative sleep disturbance and low muscle mass in patients with gastrointestinal cancer. [Participants and Methods] This cross-sectional survey enrolled 86 elderly patients (aged more than 60 years) with gastrointestinal cancer who were scheduled for curative surgery. Low preoperative muscle mass was defined according to Asian Working Group for Sarcopenia criteria. Sleep disturbance was assessed using the Japanese version of the Pittsburgh Sleep Quality Index, including the subscales. [Results] Twenty-seven patients (31%) were classified as having low muscle mass. After adjusting for confounding factors, bad sleep quality, determined by the subscales, was significantly associated with low muscle mass. [Conclusion] Our results suggest that the evaluation of sleep quality is imperative for addressing low preoperative muscle mass in patients with gastrointestinal cancer.

TRAF6 maintains mammary stem cells and promotes pregnancy-induced mammary epithelial cell expansion

Receptor activator of nuclear factor (NF)-κB (RANK) signaling promotes pregnancy-dependent epithelial cell differentiation and expansion for mammary gland development, which requires NF-κB pathway-dependent Cyclin D1 induction and inhibitor of DNA binding 2 (Id2) pathway-dependent anti-apoptotic gene induction. However, the roles of tumor necrosis factor receptor-associated factor 6 (TRAF6) remain unclear despite its requirement in RANK signaling. Here we show that TRAF6 is crucial for both mammary stem cell maintenance and pregnancy-induced epithelial cell expansion. TRAF6 deficiency impairs phosphoinositide 3-kinase (PI3K)/AKT and canonical NF-κB pathways, whereas noncanonical NF-κB signaling remains functional. Therefore, we propose that TRAF6 promotes cell proliferation by activating PI3K/AKT signaling to induce retinoblastoma phosphorylation in concert with noncanonical NF-κB pathway-dependent Cyclin D1 induction. Furthermore, TRAF6 inhibits apoptosis by activating canonical NF-κB signaling to induce anti-apoptotic genes with the Id2 pathway. Therefore, proper orchestration of TRAF6-dependent and -independent RANK signals likely establishes mammary gland formation.

Abstract B02: Intratumoral bidirectional transitions between epithelial and mesenchymal cells in triple-negative breast cancer

Epithelial-mesenchymal transition (EMT) and its reverse process, MET, are crucial in cancer metastasis. EMT allows cancer cells to move to proximal blood vessels for intravasation. However, because EMT and MET processes are dynamic, mesenchymal cancer cells are likely to undergo MET to form metastatic foci and subsequently re-undergo EMT to restart the metastatic process. To elucidate such regulation, we chose HCC38, a human triple-negative breast cancer (TNBC) cell line, because HCC38 is composed of epithelial and mesenchymal populations. We purified epithelial and mesenchymal cells from Venus-labeled and unlabeled HCC38 and mixed them at various ratios to follow EMT and MET. Using this system, we demonstrate that the two populations significantly enhance the transition of cells from the other population to their own. In addition, knockdown of ZEB1 or SLUG significantly suppressed EMT but promoted partial MET. We also demonstrate that primary breast cancer cells underwent EMT. These changes were very similar to those observed in EMT in HCC38. Consequently, we propose HCC38 as a suitable model to analyze EMT-MET dynamics that could affect development of TNBC.

Citation Format: Mizuki Yamamoto, Jun-ichiro Inoue. Intratumoral bidirectional transitions between epithelial and mesenchymal cells in triple-negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr B02.

Anemia Is a Novel Predictive Factor for the Onset of Severe Chemotherapy-Induced Peripheral Neuropathy in Lymphoma Patients Receiving Rituximab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone Therapy

Chemotherapy-induced peripheral neuropathy (CIPN) frequently occurs in lymphoma patients receiving R-CHOP, a drug combination therapy. Although severe CIPN may lead to reduction and/or discontinuation of the medication, predictive factors of CIPN have not been investigated sufficiently to date. We performed a retrospective exploratory research to determine associations between prevalence of severe CIPN and sociodemographic data, health characteristics, and medical conditions such as anemia at initial diagnosis. Forty patients (indolent lymphoma, n = 9; diffuse large B-cell lymphoma; n = 31) received R-CHOP therapy from September 2009 to July 2014. The median age of patients was 58 years (range = 27–76 years). Statistical analyses were applied to the patients, who were divided into two groups: mild CIPN (no symptoms or grade 1 according to the CTCAE version 3.0 program) and severe CIPN patients (grade 2 or higher). Forward stepwise logistic regression analyses were performed using the following variables: sex, BMI, BSA, hyperglycemia, malnutrition, and anemia. Severe CIPN occurred in seven patients (17.5%). Gender and anemia remained following the stepwise procedure, and anemia predicted severe CIPN significantly (OR = 19.45, 95% confidence interval = 1.52–171.12). Our study suggests that anemia at initial diagnosis could be a predictive factor of R-CHOP-induced CIPN.

Impact of Sarcopenia on Unplanned Readmission and Survival After Esophagectomy in Patients with Esophageal Cancer

BACKGROUND

Although sarcopenia increases postoperative complications following esophagectomy, its effects on prognosis remain unclear. This study was performed to identify the effect of sarcopenia on 90-day unplanned readmission and overall survival (OS) after esophagectomy.

METHODS

Ninety-eight patients with esophageal cancer who underwent esophagectomy were enrolled in this study. Unplanned readmission was defined as any emergent hospitalization within 90 days after discharge. Sarcopenia, defined as low muscle mass plus low muscle strength and/or low physical performance according to the Asian consensus definition, was assessed prior to esophagectomy. Multivariate logistic regression analysis was performed to identify factors that contributed to 90-day unplanned readmission. OS was estimated using the Kaplan-Meier method, and a Cox proportional hazards model was used to assess the relationship between sarcopenia and OS.

RESULTS

Thirty-one patients (31.6%) were diagnosed with sarcopenia. The 90-day unplanned readmission rate was significantly higher in patients with sarcopenia than those without (42.9% vs. 16.4%, respectively; p = 0.01). Multivariable logistic regression analysis showed that sarcopenia was an independent predictor of 90-day unplanned readmission [odds ratio 3.71, 95% confidence interval (CI) 1.29-11.05; p = 0.02], and the log-rank test showed that sarcopenia was associated with OS (p = 0.01). Moreover, sarcopenia was a significant predictor of OS after adjustment for age, sex, and pathological stage (hazard ratio 2.35, 95% CI 1.21-4.54; p = 0.01).

CONCLUSIONS

Sarcopenia is a risk factor for 90-day unplanned readmission and OS following esophagectomy. Assessment of sarcopenia could help to identify patients at higher risk of a poor prognosis after esophagectomy.

HTLV-1 Tax Induces Formation of the Active Macromolecular IKK Complex by Generating Lys63- and Met1-Linked Hybrid Polyubiquitin Chains

The Tax protein of human T-cell leukemia virus type 1 (HTLV-1) is crucial for the development of adult T-cell leukemia (ATL), a highly malignant CD4+ T cell neoplasm. Among the multiple aberrant Tax-induced effects on cellular processes, persistent activation of transcription factor NF-κB, which is activated only transiently upon physiological stimulation, is essential for leukemogenesis. We and others have shown that Tax induces activation of the IκB kinase (IKK) complex, which is a critical step in NF-κB activation, by generating Lys63-linked polyubiquitin chains. However, the molecular mechanism underlying Tax-induced IKK activation is controversial and not fully understood. Here, we demonstrate that Tax recruits linear (Met1-linked) ubiquitin chain assembly complex (LUBAC) to the IKK complex and that Tax fails to induce IKK activation in cells that lack LUBAC activity. Mass spectrometric analyses revealed that both Lys63-linked and Met1-linked polyubiquitin chains are associated with the IKK complex. Furthermore, treatment of the IKK-associated polyubiquitin chains with Met1-linked-chain-specific deubiquitinase (OTULIN) resulted in the reduction of high molecular weight polyubiquitin chains and the generation of short Lys63-linked ubiquitin chains, indicating that Tax can induce the generation of Lys63- and Met1-linked hybrid polyubiquitin chains. We also demonstrate that Tax induces formation of the active macromolecular IKK complex and that the blocking of Tax-induced polyubiquitin chain synthesis inhibited formation of the macromolecular complex. Taken together, these results lead us to propose a novel model in which the hybrid-chain-dependent oligomerization of the IKK complex triggered by Tax leads to trans-autophosphorylation-mediated IKK activation.

Integrative Network Analysis Combined with Quantitative Phosphoproteomics Reveals Transforming Growth Factor-beta Receptor type-2 (TGFBR2) as a Novel Regulator of Glioblastoma Stem Cell Properties

Glioblastoma is one of the most malignant brain tumors with poor prognosis and their development and progression are known to be driven by glioblastoma stem cells. Although glioblastoma stem cells lose their cancer stem cell properties during cultivation in serum-containing medium, little is known about the molecular mechanisms regulating signaling alteration in relation to reduction of stem cell-like characteristics. To elucidate the global phosphorylation-related signaling events, we performed a SILAC-based quantitative phosphoproteome analysis of serum-induced dynamics in glioblastoma stem cells established from the tumor tissues of the patient. Among a total of 2876 phosphorylation sites on 1584 proteins identified in our analysis, 732 phosphorylation sites on 419 proteins were regulated through the alteration of stem cell-like characteristics. The integrative computational analyses based on the quantified phosphoproteome data revealed the relevant changes of phosphorylation levels regarding the proteins associated with cytoskeleton reorganization such as Rho family GTPase and Intermediate filament signaling, in addition to transforming growth factor-β receptor type-2 (TGFBR2) as a prominent upstream regulator involved in the serum-induced phosphoproteome regulation. The functional association of transforming growth factor-β receptor type-2 with stem cell-like properties was experimentally validated through signaling perturbation using the corresponding inhibitors, which indicated that transforming growth factor-β receptor type-2 could play an important role as a novel cell fate determinant in glioblastoma stem cell regulation.

Hypergravity Provokes a Temporary Reduction in CD4+CD8+ Thymocyte Number and a Persistent Decrease in Medullary Thymic Epithelial Cell Frequency in Mice

Gravity change affects many immunological systems. We investigated the effects of hypergravity (2G) on murine thymic cells. Exposure of mice to 2G for three days reduced the frequency of CD4⁺CD8⁺ thymocytes (DP) and mature medullary thymic epithelial cells (mTECs), accompanied by an increment of keratin-5 and keratin-8 double-positive (K5⁺K8⁺) TECs that reportedly contain TEC progenitors. Whereas the reduction of DP was recovered by a 14-day exposure to 2G, the reduction of mature mTECs and the increment of K5⁺K8⁺ TEC persisted. Interestingly, a surgical lesion of the inner ear’s vestibular apparatus inhibited these hypergravity effects. Quantitative PCR analysis revealed that the gene expression of Aire and RANK that are critical for mTEC function and development were up-regulated by the 3-day exposure and subsequently down-regulated by the 14-day exposure to 2G. Unexpectedly, this dynamic change in mTEC gene expression was independent of the vestibular apparatus. Overall, data suggest that 2G causes a temporary reduction of DP and a persistent reduction of mature mTECs in a vestibular system-dependent manner, and also dysregulates mTEC gene expression without involving the vestibular system. These data might provide insight on the impact of gravity change on thymic functions during spaceflight and living.

Loss of Tifab, a del(5q) MDS gene, alters hematopoiesis through derepression of Toll-like receptor-TRAF6 signaling

Varney et al. report that that deletion of the TRAF-interacting protein TIFAB contributes to an MDS-like phenotype in mice by up-regulating TRAF6 and contributing to hematopoietic dysfunction.

TRAF-interacting protein with forkhead-associated domain B (TIFAB) is a haploinsufficient gene in del(5q) myelodysplastic syndrome (MDS). Deletion of Tifab results in progressive bone marrow (BM) and blood defects, including skewed hematopoietic stem/progenitor cell (HSPC) proportions and altered myeloid differentiation. A subset of mice transplanted with Tifab knockout (KO) HSPCs develop a BM failure with neutrophil dysplasia and cytopenia. In competitive transplants, Tifab KO HSPCs are out-competed by wild-type (WT) cells, suggesting a cell-intrinsic defect. Gene expression analysis of Tifab KO HSPCs identified dysregulation of immune-related signatures, and hypersensitivity to TLR4 stimulation. TIFAB forms a complex with TRAF6, a mediator of immune signaling, and reduces TRAF6 protein stability by a lysosome-dependent mechanism. In contrast, TIFAB loss increases TRAF6 protein and the dynamic range of TLR4 signaling, contributing to ineffective hematopoiesis. Moreover, combined deletion of TIFAB and miR-146a, two genes associated with del(5q) MDS/AML, results in a cooperative increase in TRAF6 expression and hematopoietic dysfunction. Re-expression of TIFAB in del(5q) MDS/AML cells results in attenuated TLR4 signaling and reduced viability. These findings underscore the importance of efficient regulation of innate immune/TRAF6 signaling within HSPCs by TIFAB, and its cooperation with miR-146a as it relates to the pathogenesis of hematopoietic malignancies, such as del(5q) MDS/AML.

Visualization of RelB expression and activation at the single-cell level during dendritic cell maturation in Relb-Venus knock-in mice

RelB is activated by the non-canonical NF-κB pathway, which is crucial for immunity by establishing lymphoid organogenesis and B-cell and dendritic cell (DC) maturation. To elucidate the mechanism of the RelB-mediated immune cell maturation, a precise understanding of the relationship between cell maturation and RelB expression and activation at the single-cell level is required. Therefore, we generated knock-in mice expressing a fusion protein between RelB and fluorescent protein (RelB-Venus) from the Relb locus. The Relb(Venus/Venus) mice developed without any abnormalities observed in the Relb(-/-) mice, allowing us to monitor RelB-Venus expression and nuclear localization as RelB expression and activation. Relb(Venus/Venus) DC analyses revealed that DCs consist of RelB(-), RelB(low) and RelB(high) populations. The RelB(high) population, which included mature DCs with projections, displayed RelB nuclear localization, whereas RelB in the RelB(low) population was in the cytoplasm. Although both the RelB(low) and RelB(-) populations barely showed projections, MHC II and co-stimulatory molecule expression were higher in the RelB(low) than in the RelB(-) splenic conventional DCs. Taken together, our results identify the RelB(low) population as a possible novel intermediate maturation stage of cDCs and the Relb(Venus/Venus) mice as a useful tool to analyse the dynamic regulation of the non-canonical NF-κB pathway.

Catalytic subunits of the phosphatase calcineurin interact with NF-κB-inducing kinase (NIK) and attenuate NIK-dependent gene expression

Nuclear factor (NF)-κB-inducing kinase (NIK) is a serine/threonine kinase that activates NF-κB pathways, thereby regulating a wide variety of immune systems. Aberrant NIK activation causes tumor malignancy, suggesting a requirement for precise regulation of NIK activity. To explore novel interacting proteins of NIK, we performed in vitro virus screening and identified the catalytic subunit Aα isoform of serine/threonine phosphatase calcineurin (CnAα) as a novel NIK-interacting protein. The interaction of NIK with CnAα in living cells was confirmed by co-immunoprecipitation. Calcineurin catalytic subunit Aβ isoform (CnAβ) also bound to NIK. Experiments using domain deletion mutants suggested that CnAα and CnAβ interact with both the kinase domain and C-terminal region of NIK. Moreover, the phosphatase domain of CnAα is responsible for the interaction with NIK. Intriguingly, we found that TRAF3, a critical regulator of NIK activity, also binds to CnAα and CnAβ. Depletion of CnAα and CnAβ significantly enhanced lymphotoxin-β receptor (LtβR)-mediated expression of the NIK-dependent gene Spi-B and activation of RelA and RelB, suggesting that CnAα and CnAβ attenuate NF-κB activation mediated by LtβR-NIK signaling. Overall, these findings suggest a possible role of CnAα and CnAβ in modifying NIK functions.

Limitation of immune tolerance-inducing thymic epithelial cell development by Spi-B-mediated negative feedback regulation

Medullary thymic epithelial cells (mTECs) expressing the autoimmune regulator AIRE and various tissue-specific antigens (TSAs) are critical for preventing the onset of autoimmunity and may attenuate tumor immunity. However, molecular mechanisms controlling mTEC development remain elusive. Here, we describe the roles of the transcription factor Spi-B in mTEC development. Spi-B is rapidly up-regulated by receptor activator of NF-κB ligand (RANKL) cytokine signaling, which triggers mTEC differentiation, and in turn up-regulates CD80, CD86, some TSAs, and the natural inhibitor of RANKL signaling, osteoprotegerin (OPG). Spi-B-mediated OPG expression limits mTEC development in neonates but not in embryos, suggesting developmental stage-specific negative feedback regulation. OPG-mediated negative regulation attenuates cellularity of thymic regulatory T cells and tumor development in vivo. Hence, these data suggest that this negative RANKL-Spi-B-OPG feedback mechanism finely tunes mTEC development and function and may optimize the trade-off between prevention of autoimmunity and induction of antitumor immunity.

Cell growth control by stable Rbg2/Gir2 complex formation under amino acid starvation

The molecular fine-tuning mechanisms underlying adaptive responses to environmental stresses in eukaryotes remain largely unknown. Here, we report on a novel stress-induced cell growth control mechanism involving a highly conserved complex containing Rbg2 and Gir2 subunits, which are the budding yeast orthologs of human Drg2 and Dfrp2, respectively. We found that the complex is responsible for efficient cell growth under amino acid starvation. Using native PAGE analyses, we observed that, individually, Rbg2 and Gir2 were labile proteins. However, they formed a complex that stabilized each other, and this stability became significantly enhanced after amino acid starvation. We observed that the stabilization of the complex was strictly dependent on GDP or GTP binding to Rbg2. A point mutation (S77N) that inactivated nucleotide binding impaired formation of the complex and disrupted the stress-induced cell growth. Interestingly, the complex bound the translational activator Gcn1 in a dose-dependent manner according to the stress level, suggesting a dynamic association with the cellular translational machinery. We propose that the Rbg2/Gir2 complex is a modulator that maintains cellular homoeostasis, thus promoting the survival of eukaryotic organisms in stressful environments.

NF-κB non-cell-autonomously regulates cancer stem cell populations in the basal-like breast cancer subtype

Patients with triple-negative breast cancer display the highest rates of early relapse of all patients with breast cancer. The basal-like subtype, a subgroup of triple-negative breast cancer, exhibits high levels of constitutively active NF-κB signalling. Here we show that NF-κB activation, induced by inflammatory cytokines or by epigenetically dysregulated NIK expression, cell-autonomously upregulates JAG1 expression in non-cancer stem cells. This upregulation stimulates NOTCH signalling in cancer stem cells in trans, leading to an expansion of cancer stem cell populations. Among breast cancers, the NF-κB-dependent induction of JAG1 and the NOTCH-dependent expansion of the cancer stem cell population occur only in the basal-like subtype. Collectively, our results indicate that NF-κB has a non-cell-autonomous role in regulating cancer stem cell populations by forming intratumoural microenvironments composed of JAG1-expressing non-cancer stem cells with a basal-like subtype.

Roles of spatial parameters on the oscillation of nuclear NF-κB: computer simulations of a 3D spherical cell

Transcription factor NF-κB resides in the cytoplasm and translocates to the nucleus by application of extracellular stimuli. It is known that the nuclear NF-κB oscillates and different oscillation patterns lead to different gene expression. Nearly forty reports on modeling and simulation of nuclear NF-κB have been published to date. The computational models reported so far are temporal or two-dimensional, and the discussions on spatial parameters have not been involved or limited. Since spatial parameters in cancer cells such as nuclear to cytoplasmic volume (N/C) ratio are different from normal cells, it is important to understand the relationship between oscillation patterns and spatial parameters. Here we report simulations of a 3D computational model for the oscillation of nuclear NF-κB using A-Cell software. First, we found that the default biochemical kinetic constants used in the temporal model cannot replicate the experimentally observed oscillation in the 3D model. Thus, the default parameters should be changed in the 3D model. Second, spatial parameters such as N/C ratio, nuclear transport, diffusion coefficients, and the location of IκB synthesis were found to alter the oscillation pattern. Third, among them, larger N/C ratios resulted in persistent oscillation of nuclear NF-κB, and larger nuclear transport resulted in faster oscillation frequency. Our simulation results suggest that the changes in spatial parameters seen in cancer cells is one possible mechanism for alteration in the oscillation pattern of nuclear NF-κB and lead to the altered gene expression in these cells.

Daily performance status-based target physical activity of early rehabilitation for hematologic malignancy patients after allogeneic hematopoietic stem cell transplantation

e17020

Background: For hematologic malignancy patients receiving allogeneic hematopoietic stem cell transplantation (allo-SCT), the maintenance and/or increase of physical activity (PA) after allo-SCT possibly lead to favorable outcomes. However, it remains to be clarified how much intensity of daily rehabilitation should be prescribed. The aim of this study was to evaluate target PA according to daily performance status (PS) in these patients. Methods: Twenty-seven allo-SCT patients were enrolled in this study (13 males, 14 females, the median age; 47 years). Written informed consent was obtained from all patients. Donor types were bone marrow (n = 12), peripheral blood stem cell (n = 6), and single-unit cord blood (n = 9). All patients received our established exercise program supervised by physical therapists just after neutrophil engraftment in a bioclean room. As an alternative value of PA, daily steps (DS) were measured by using a uniaxial pedometer (Lifecorder EX, Suzuken Co. Ltd., Nagoya, Japan), and Eastern Cooperative Oncology Group PS after allo-SCT were also assessed daily for each individual. The data were statistically analyzed by using ANOVA and Scheff 's tests. Results: A correlation between DS and PS was observed. After the early physical intervention, the mean DS of patients with PS 1, 2, or 3 in a bioclean room were 2,411 ± 1,068, 1,205 ± 572, and 597 ± 216 steps/day, respectively. DS significantly declined by about 50% according to one grade deterioration of PS. Conclusions: As the target PA correlated with PS seems to be existence, we should plan daily activity in a bioclean room to keep more than above-mentioned mean DS according to daily PS for allo-SCT patients.

An artificial copper complex incorporating a cell-penetrating peptide inhibits nuclear factor-κB (NF-κB) activation

Nuclear factor-κB (NF-κB) is an inducible transcription factor activated by a variety of cytokines, and promotes the transcription of genes involved in cancer, inflammation, autoimmune disease, and viral infection, among others. Because of its involvement in numerous disease processes, considerable research has focused on NF-κB as a potential drug target. We previously reported that cupric ion (Cu(2+)) blocks NF-κB activation. However, Cu(2+) is unsuitable for drug applications. The copper complex of an artificial peptide HPH-Pep (HPH-Pep-Cu(2+)) was a promising alternative, but it did not easily cross the cell membrane. We report the development of a NF-κB inhibiting Cu(2+) complex with improved cell-penetrating activity arising from the coupling of a Tat peptide to HPH-Pep-Cu(2+).

Identification of interleukin-1 receptor-associated kinase 1 as a critical component that induces post-transcriptional activation of IκB-ζ

IκB-ζ, an essential inflammatory regulator, is specifically induced by Toll-like receptor ligands or interleukin (IL)-1β by post-transcriptional activation mediated via a 165-nucleotide element in IκB-ζ mRNA. Here, we analyzed the Toll-like receptor-IL-1 receptor signaling components involved in the post-transcriptional regulation of IκB-ζ with mutated estrogen receptor [ER(T2)] fusion proteins. Upon 4-hydroxytamoxifen treatment, the ER(T2) fusion proteins with IL-1 receptor-associated kinase (IRAK)1 and IRAK4 elicited specific activation of a reporter gene for the post-transcriptional regulation of IκB-ζ. The tumor necrosis factor receptor-associated factor (TRAF)6-ER(T2) protein activated nuclear factor-κB, but not post-transcriptional regulation, indicating that activation of IRAK1/4, but not of TRAF6, is sufficient to activate the 165-nucleotide element-mediated post-transcriptional mechanism. Interestingly, the post-transcriptional mechanism was not activated in TRAF6-deficient cells, indicating an essential role for TRAF6. Thus, the signaling pathway leading to nuclear factor-κB activation and the post-transcriptional activation bifurcates at IRAK1, suggesting a new pathway activated by IRAK1.

Activation of the IκB kinase complex by HTLV-1 Tax requires cytosolic factors involved in Tax-induced polyubiquitination

Activation of NF-κB by human T cell leukaemia virus type 1 Tax is thought to be crucial in T-cell transformation and the onset of adult T cell leukaemia. Tax activates NF-κB through activation of the IκB kinase (IKK) complex, similar to cytokine-induced NF-κB activation, which involves active signalling complex formation using polyubiquitin chains as a platform. Although polyubiquitination of Tax was reported to be required for IKK activation, most studies have been performed using intact cells, in which secondary NF-κB activation can be induced by various cytokines that are secreted due to Tax-mediated primary NF-κB activation. Therefore, a cell-free assay system, in which IKK can be activated by adding highly purified recombinant Tax to cytosolic extract, was used to analyse Tax-induced IKK activation. In contrast to the cytosolic extract, the purified IKK complex was not activated by Tax, whereas, it was efficiently activated by MEKK1, that does not require polyubiquitination to activate IKK. Moreover, Tax-induced IKK activation was blocked when the cytosolic extract was mixed with either lysine-free, methylated or K63R ubiquitin. These results obtained through our cell-free assay suggest that K63-linked polyubiquitination is critical, but linear polyubiquitination is dispensable or insufficient for Tax-induced IKK activation.

RANK signaling induces interferon-stimulated genes in the fetal thymic stroma

Medullary thymic epithelial cells (mTECs) are essential for thymic negative selection to prevent autoimmunity. Previous studies show that mTEC development is dependent on the signal transducers TRAF6 and NIK. However, the downstream target genes of signals controlled by these molecules remain unknown. We performed a microarray analysis on mRNAs down-regulated by deficiencies in TRAF6 or functional NIK in an in vitro organ culture of fetal thymic stromata (2DG-FTOC). An in silico analysis of transcription factor binding sites in plausible promoter regions of differentially expressed genes suggests that STAT1 is involved in TRAF6- and NIK-dependent gene expression. Indeed, the signal of RANK, a TNF receptor family member that activates TRAF6 and NIK, induces the activation of STAT1 in 2DG-FTOC. Moreover, RANK signaling induces the up-regulation of interferon (IFN)-stimulated gene (ISG) expression, suggesting that the RANKL-dependent activation of STAT1 up-regulates ISG expression. The RANKL-dependent expression levels of ISGs were reduced but not completely abolished in interferon α receptor 1-deficient (Ifnar1(-/-)) 2DG-FTOC. Our data suggest that RANK signaling induces ISG expression in both type I interferon-independent and interferon-dependent mechanisms.

Paracrine IL-33 stimulation enhances lipopolysaccharide-mediated macrophage activation

Background

IL-33, a member of the IL-1 family of cytokines, provokes Th2-type inflammation accompanied by accumulation of eosinophils through IL-33R, which consists of ST2 and IL-1RAcP. We previously demonstrated that macrophages produce IL-33 in response to LPS. Some immune responses were shown to differ between ST2-deficient mice and soluble ST2-Fc fusion protein-treated mice. Even in anti-ST2 antibody (Ab)-treated mice, the phenotypes differed between distinct Ab clones, because the characterization of such Abs (i.e., depletion, agonistic or blocking Abs) was unclear in some cases.

Methodology/Principal Findings

To elucidate the precise role of IL-33, we newly generated neutralizing monoclonal Abs for IL-33. Exogenous IL-33 potentiated LPS-mediated cytokine production by macrophages. That LPS-mediated cytokine production by macrophages was suppressed by inhibition of endogenous IL-33 by the anti-IL-33 neutralizing mAbs.

Conclusions/Significance

Our findings suggest that LPS-mediated macrophage activation is accelerated by macrophage-derived paracrine IL-33 stimulation.

Lymphotoxin signal promotes thymic organogenesis by eliciting RANK expression in the embryonic thymic stroma

It has recently become clear that signals mediated by members of the TNFR superfamily, including lymphotoxin-β receptor (LTβR), receptor activator for NF-κB (RANK), and CD40, play essential roles in organizing the integrity of medullary thymic epithelial cells (mTECs) required for the establishment of self-tolerance. However, details of the mechanism responsible for the unique and cooperative action of individual and multiple TNFR superfamily members during mTEC differentiation still remain enigmatic. In this study, we show that the LTβR signal upregulates expression of RANK in the thymic stroma, thereby promoting accessibility to the RANK ligand necessary for mTEC differentiation. Cooperation between the LTβR and RANK signals for optimal mTEC differentiation was underscored by the exaggerated defect of thymic organogenesis observed in mice doubly deficient for these signals. In contrast, we observed little cooperation between the LTβR and CD40 signals. Thus, the LTβR signal exhibits a novel and unique function in promoting RANK activity for mTEC organization, indicating a link between thymic organogenesis mediated by multiple cytokine signals and the control of autoimmunity.

Therapeutic potential of anti-interleukin-17A aptamer: suppression of interleukin-17A signaling and attenuation of autoimmunity in two mouse models

OBJECTIVE

The proinflammatory cytokine interleukin-17A (IL-17A) is produced primarily by the CD4+ T cell subset called Th17 cells, which is involved in host defense, inflammation, and autoimmune disorders. This study was undertaken to investigate the effect of a high-affinity RNA molecule, called an aptamer, against human IL-17A on IL-17A-induced signal transduction in vitro and its anti-autoimmune efficacy in vivo in 2 mouse models of inflammation.

METHODS

By screening a large library of nuclease-resistant RNA oligonucleotides, we selected an RNA aptamer, Apt21-2, that binds human and mouse IL-17 and blocks the interaction between IL-17A and its receptor. The inhibition of IL-17A-mediated phosphorylation and marker protein production was analyzed in human and mouse cells. Mice with glucose-6-phosphate isomerase (GPI)-induced rheumatoid arthritis and myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis were used to assess efficacy.

RESULTS

Apt21-2 prevented efficient phosphorylation of the IL-17A signaling factors IκB and JNK and inhibited the production of IL-6 in human and mouse cells. A PEGylated form of Apt21-2 (PEG21-2idT) exhibited a 50% inhibition concentration (IC(50) ) in the range of 1-2 nM and 70-80 nM in human and mouse cells, respectively. When administered immediately after immunization with GPI or MOG, PEG21-2idT inhibited in a dose-dependent manner the development of arthritic or neurologic symptoms. Significantly, PEG21-2idT slowed the progression of arthritis when administered after the onset of GPI-induced arthritis.

CONCLUSION

Our findings indicate that the chemically processed anti-IL-17A aptamer PEG21-2idT inhibits the actions of IL-17A as well as the development of autoimmunity in 2 mouse models of inflammation. These results offer for the first time an aptamer-based therapeutic approach to the treatment of Th17 cell-mediated autoimmune disorders.