Expression Of Cbl-b Research Articles

Investigation of CBL-b, c-CBL expressions in colorectal cancer patients and their relationship with clinicopathological characteristics

Introduction: Colorectal cancer (CRC) is the most common gastrointestinal cancer and a major cause of cancer-related mortality worldwide. Molecular indicators of pathogenic factors that regulate CRC, which are known as oncogenes, are desirable for response to treatment and improvement of CRC patient management. Several risk factors play a role in the development of this disease, which can occur genetically, familial, or sporadically. CRC tumorigenesis is stimulated by the proto-oncogene β-catenin (wnt/β-catenin). Casitas B-lineage lymphoma (c-Cbl) inhibits CRC tumor growth through an unknown mechanism that affects nuclear β-catenin. The current objective of this study is to evaluate the expression levels of Cbl-b and c-Cbl genes to determine if their transcripts can be used as suitable diagnostic indicators. Additionally, we aim to investigate the correlation between clinicopathological information of CRC patients and the levels of Cbl-b and c-Cbl. Materials and Methods: Quantitative Real-Time PCR (qRT-PCR) method was used to evaluate the expression levels of Cbl-b and c-Cbl in 45 colorectal tumor tissues and 45 adjacent control tissues. Furthermore, we analyzed the diagnostic power of Cbl-b and c-Cbl by plotting receiver operating characteristic (ROC) curves. Results: Our results showed that the expression levels of Cbl-b and c-Cbl were significantly increased in CRC patients compared to the adjacent control group (P<0.003, P<0.004). Analysis of clinicopathological features of CRC patients revealed that the expression of Cbl-b and c-Cbl was associated differently with TMN stage, LVI+ (P<0.0003, P<0.0001) (P<0.003, P<0.07). Conclusion: These results indicate that the levels of Cbl-b and c-Cbl may serve as potential diagnostic indicators for CRC.

Involvement of the E3 ubiquitin ligase Cblb in host defense and evaluation of transcriptome during Trueperella pyogenes infection

Trueperella pyogenes (T. pyogenes) is a versatile and ingenious bacterium that causes severe suppurative injuries in lots of economically important ruminants. The underlying pathogenesis of T. pyogenes infection remains poorly understood. In the current study, we performed transcriptome sequencing of mouse blood tissue infected with T. pyogenes. A total of 36.73 G clean data were collected, and 136 differentially expressed genes were obtained in the infection group compared to the control group. In addition, we found that the E3 ubiquitin ligase Cblb exhibited significant upregulation in the infection groups compared to the control group. Mechanistically, T. pyogenes infection markedly enhanced the expression of Cblb and regulated the host defense response. Inhibiting Cblb expression with Cblb siRNA impaired the inflammatory response and reduced the effect of phagocytosis in RAW264.7 murine macrophages. Intriguingly, overexpression of Cblb induced a strong inflammatory response and enhanced phagocytosis against T. pyogenes infection in macrophages. More importantly, the overexpression of Cblb significantly reduced the bacterial load and protected mice from the T. pyogenes infections. Therefore, our findings reveal that Cblb is a novel and potential regulator in response to T. pyogenes infection and shed new light on the development of promising treatments against T. pyogenes-related diseases.

Morin improves dexamethasone-induced muscle atrophy by modulating atrophy-related genes and oxidative stress in female mice.

This study investigated the effect of morin, a flavonoid, on dexamethasone-induced muscle atrophy in C57BL/6J female mice. Dexamethasone (10 mg/kg body weight) for 10 days significantly reduced body weight, gastrocnemius and tibialis anterior muscle mass, and muscle protein in mice. Dexamethasone significantly upregulated muscle atrophy-associated ubiquitin ligases, including atrogin-1 and MuRF-1, and the upstream transcription factors FoxO3a and Klf15. Additionally, dexamethasone significantly induced the expression of oxidative stress-sensitive ubiquitin ligase Cbl-b and the accumulation of the oxidative stress markers malondialdehyde and advanced protein oxidation products in both the plasma and skeletal muscle samples. Intriguingly, morin treatment (20 mg/kg body weight) for 17 days effectively attenuated the loss of muscle mass and muscle protein and suppressed the expression of ubiquitin ligases while reducing the expression of upstream transcriptional factors. Therefore, morin might act as a potential therapeutic agent to attenuate muscle atrophy by modulating atrophy-inducing genes and preventing oxidative stress.

MiR-27b-3p Attenuates Muscle Atrophy by Targeting Cbl-b in Skeletal Muscles

As it is well known, muscle atrophy is a process in which protein degradation increases and protein synthesis decreases. This process is regulated by a variety of links. Among them, microRNAs play an essential role in this process, which has attracted widespread attention. In this paper, we find that miR-27b-3p and Cbl-b genes are significantly differentially expressed in the induced atrophy model. The dual-luciferase experiment and Western blot analysis confirmed that miR-27b-3p could regulate the expression of Cbl-b. In C2C12-differentiated myotubes, the overexpression of the Cbl-b gene showed that Cbl-b could upregulate the expression of MuRF-1 and Atrogin-1, which are related marker genes of muscle atrophy, at both the mRNA and protein levels, indicating that the Cbl-b gene can specifically affect muscle atrophy. The knockdown of the Cbl-b gene after C2C12-differentiated myotubes induced atrophy treatment can downregulate the expression of muscle-atrophy-related genes, indicating that manual intervention to downregulate the expression of Cbl-b has a certain alleviating effect on muscle atrophy. These data suggest that miR-27b-3p can regulate the expression of the Cbl-b gene and then exert a particular influence on muscle atrophy through the Cbl-b gene.

Mechanism of Yangxinshi Intervention on Cardiac Fibrosis in Diabetic Cardiomyopathy Based on Network Pharmacology

Background Cardiac fibrosis (CF) is major myocardial change in diabetic cardiomyopathy (DCM). Yangxinshi as a Chinese medicine formula is used to treat cardiovascular diseases. However, the exact effective mechanism of Yangxinshi on CF is still uncertain. Hence, based on the pharmacological network, predicting the active components, potential targets and pathways of Yangxinshi on diabetic fibrosis require to be further studied. Materials and Methods By using Cytoscape 3.6.0 Bisogenet plug-in, the active components of Yangxinshi were obtained and screened through TCMSP, and the PPI network of DCM-CF was constructed and then screened by CytoNCA plug-in. GO analysis and KEGG pathway enrichment analysis were carried out by Cluego plug-in. Combined with the results of network pharmacological analysis, cells in vitro were performed to verify the CF stimulated with high glucose or intervence with Yangxinshi, and the expressions of Cbl-b, p-smad2, and α-SMA were detected. Results Yangxinshi might play a key role in reversing cardiac fibrosis in individuals with DCM by regulating the signal pathway of CBL and promoted the expression of Cbl-b and inhibited the expression of p-smad2 and α-SMA, verifying some predictive work via network pharmacology. Conclusion Based on network pharmacology, this study demonstrates that the beneficial effect of Yangxinshi on CF is related to the Cbl-b/smad2 pathway, providing an idea for the therapeutic effect of Yangxinshi on cardiac fibrosis in DCM.

Upregulation of T Cell Receptor Signaling Pathway Components in Gestational Diabetes Mellitus Patients: Joint Analysis of mRNA and circRNA Expression Profiles.

ObjectiveGestational diabetes mellitus (GDM) is one of the most common complications of pregnancy, and its pathogenesis is still unclear. Studies have shown that circular RNAs (circRNAs) can regulate blood glucose levels by targeting mRNAs, but the role of circRNAs in GDM is still unknown. Therefore, a joint microarray analysis of circRNAs and their target mRNAs in GDM patients and healthy pregnant women was carried out.MethodsIn this study, microarray analyses of mRNA and circRNA in 6 GDM patients and 6 healthy controls were conducted to identify the differentially expressed mRNA and circRNA in GDM patients, and some of the discovered mRNAs and circRNAs were further validated in additional 56 samples by quantitative realtime PCR (qRT-PCR) and droplet digital PCR (ddPCR).ResultsGene ontology and pathway analyses showed that the differentially expressed genes were significantly enriched in T cell immune-related pathways. Cross matching of the differentially expressed mRNAs and circRNAs in the top 10 KEGG pathways identified 4 genes (CBLB, ITPR3, NFKBIA, and ICAM1) and 4 corresponding circRNAs (circ-CBLB, circ-ITPR3, circ-NFKBIA, and circ-ICAM1), and these candidates were subsequently verified in larger samples. These differentially expressed circRNAs and their linear transcript mRNAs were all related to the T cell receptor signaling pathway, and PCR results confirmed the initial microarray results. Moreover, circRNA/miRNA/mRNA interactions and circRNA-binding proteins were predicted, and circ-CBLB, circ-ITPR3, and circ-ICAM1 may serve as GDM-related miRNA sponges and regulate the expression of CBLB, ITPR3, NFKBIA, and ICAM1 in cellular immune pathways.ConclusionUpregulation of T cell receptor signaling pathway components may represent the major pathological mechanism underlying GDM, thus providing a potential approach for the prevention and treatment of GDM.

Admixture mapping reveals the association between Native American ancestry at 3q13.11 and reduced risk of Alzheimer\u2019s disease in Caribbean Hispanics

BackgroundGenetic studies have primarily been conducted in European ancestry populations, identifying dozens of loci associated with late-onset Alzheimer’s disease (AD). However, much of AD’s heritability remains unexplained; as the prevalence of AD varies across populations, the genetic architecture of the disease may also vary by population with the presence of novel variants or loci.MethodsWe conducted genome-wide analyses of AD in a sample of 2565 Caribbean Hispanics to better understand the genetic contribution to AD in this population. Statistical analysis included both admixture mapping and association testing. Evidence for differential gene expression within regions of interest was collected from independent transcriptomic studies comparing AD cases and controls in samples with primarily European ancestry.ResultsOur genome-wide association study of AD identified no loci reaching genome-wide significance. However, a genome-wide admixture mapping analysis that tests for association between a haplotype’s ancestral origin and AD status detected a genome-wide significant association with chromosome 3q13.11 (103.7–107.7Mb, P = 8.76E−07), driven by a protective effect conferred by the Native American ancestry (OR = 0.58, 95%CI = 0.47−0.73). Within this region, two variants were significantly associated with AD after accounting for the number of independent tests (rs12494162, P = 2.33E−06; rs1731642, P = 6.36E−05). The significant admixture mapping signal is composed of 15 haplotype blocks spanning 5 protein-coding genes (ALCAM, BBX, CBLB, CCDC54, CD47) and four brain-derived topologically associated domains, and includes markers significantly associated with the expression of ALCAM, BBX, CBLB, and CD47 in the brain. ALCAM and BBX were also significantly differentially expressed in the brain between AD cases and controls with European ancestry.ConclusionThese results provide multiethnic evidence for a relationship between AD and multiple genes at 3q13.11 and illustrate the utility of leveraging genetic ancestry diversity via admixture mapping for new insights into AD.

Hypoxia-mediated down-regulation of miRNAs' biogenesis promotes tumor immune escape in bladder cancer.

The study examines the function of hypoxia-mediated down-regulation of microRNAs (miRNAs) (mir-30c, mir-135a, and mir-27a) in the process of bladder cancer immune escape. Quantitative Real-time PCR (qRT-PCR) was carried out to determine gene expression levels of Drosha and Dicer under hypoxia treatment, while western blotting and flow cytometry were used to determine protein expression. Seven reported miRNAs were identified via qRT-PCR assay. Flow cytometry detection of CD3/CD4/CD8-positive expression and statistics. Enzyme-linked immunosorbent assay (ELISA) detected cellular immune factors content. Cell apoptosis was checked via flow cytometry assay. Luciferase report assay and western blot assays were both used to verify the relationship between miRNAs and Casitas B-lineage lymphoma proto-oncogene b (Cbl-b). The animal model was established and Hematoxylin-eosin (HE) staining, TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, and immunohistochemistry (IHC) assays were separately used to verify the conclusions. The CD3 + /CD4 + expression was increased in the hypoxia group, while CD3 + /CD8 + expression, the cellular immune factors content Interleukin-2 (IL-2) and Tumor Necrosis Factor-α (TNFα) along with the cell apoptosis were suppressed. The protein expression of Cbl-b was found to be up-regulated in the hypoxia group. After constructing the overexpression/ knockdown of Cbl-b in peripheral blood mononuclear cell (PBMC), Cbl-b has been found to promote tumor immune escape in bladder cancer. Furthermore, Cbl-b had been identified as the co-targets of mir-30c, mir-135a, and mir-27a and down-regulation of miRNA biogenesis promotes Cbl-b expression and deactivating T cells in vitro/in vivo. Hypoxia-mediated down-regulation of miRNAs' biogenesis promotes tumor immune escape in bladder cancer, which could bring much more advance to the medical research on tumors.

Cbl-b Is Upregulated and Plays a Negative Role in Activated Human NK Cells.

The E3 ubiquitin ligase Cbl-b has been characterized as an intracellular checkpoint in T cells; however, the function of Cbl-b in primary human NK cells, an innate immune anti-tumor effector cell, is not well defined. In this study, we show that the expression of Cbl-b is significantly upregulated in primary human NK cells activated by IL-15, IL-2, and the human NK cell-sensitive tumor cell line K562 that lacks MHC class I expression. Pretreatment with JAK or AKT inhibitors prior to IL-15 stimulation reversed Cbl-b upregulation. Downregulation of Cbl-b resulted in significant increases in granzyme B and perforin expression, IFN-γ production, and cytotoxic activity against tumor cells. Collectively, we demonstrate upregulation of Cbl-b and its inhibitory effects in IL-15/IL-2/K562-activated human NK cells, suggesting that Cbl-b plays a negative feedback role in human NK cells.

The effect of Casitas b-lineage lymphoma b on regulating T follicular helper in lupus nephritis.

The purpose of this study was to investigate the effect of Casitas b-lineage lymphoma b (Cblb) on the regulation of T follicular helper (Tfh) in the development of lupus nephritis. The Tfh (CD4+CXCR5+PD-1+) cells in peripheral blood were analyzed by flow cytometry. Forty mice were divided into 4 groups (10/group), WT, lpr, Cblb-/- and lpr.Cblb-/-. Urine protein, serum creatinine, blood urea nitrogen (BUN), dsDNA, and antinuclear antibody (ANA) titer of mice were monitored once every four weeks. Peripheral blood mononuclear cells (PBMCs) from mice were collected to assess circulating Tfh. The expressions of Cblb in Tfh cells were regulated by transfecting siRNA and overexpression plasmid approach in vitro. The patients with lupus nephritis (LN) had abnormal renal clinical manifestations compared with healthy volunteers. The peripheral Tfh cells were increased and the expression of Cblb were downregulated in patients with LN (p<0.05). Both lpr mice and lpr.Cblb-/- mice had LN symptoms. LN symptoms were more serious in lpr.Cblb-/- mice compared with that in lpr mice (p<0.05). The number of Tfh cells in peripheral blood from lpr.Cblb-/- mice was significantly higher than that from lpr mice (p<0.05). Overexpression of Cblb in Tfh cells led to reduction of IgG expression, while the knockdown of Cblb in Tfh cells was accompanied by increased expression of immunoglobulin (IgG) (p<0.05). Cblb showed a negative regulatory effect on Tfh. The deletion of Cblb may be a key factor in progression of renal injury.

REGULATION OF T FOLLICULAR CELL DEVELOPMENT BY E3 UBIQUITIN LIGASE CBL-B IN SYSTEMIC LUPUS ERYTHEMATOSUS

Abstract T follicular helper cells (Tfh) are critical in providing help to B cells, and have been shown to be involved in the overproduction of pathogenic auto-Abs and tissue damage in lupus. Cbl-b, a RING finger E3 ubiquitin ligase, negatively regulates lymphocyte activation. In this study, we found that the expression of Cbl-b in CD4+ T cells from lpr mice on a C57BL/6 background (B6-lpr) was down-regulated. Introducing Cbl-b deficiency or Cbl-b C373A mutation into B6-lpr mice significantly exacerbated the onset of the disease in B6-lpr mice, which correlated with heightened serum auto-antibody titers, exaggerated Tfh, GC B cells, and plasma cells. These data indicate that Cbl-b negatively regulates lupus disease progression and Tfh development via its E3 ubiquitin ligase activity. In support of a critical role of Cbl-b in Tfh development, mice specifically deficient for Cbl-b in T cells also exhibited an increase in Tfh when they were immunized with OVA in CFA. Mechanistically, Cbl-b appeared to specifically bind to Bcl6, and target Bcl-6 for ubiquitination and degradation. In strong support of Cbl-b in exaggerated Tfh in lupus, we found that Tfh cells were increased in the peripheral blood of SLE patients. Furthermore, Cbl-b expression was significantly reduced in Tfh from patient with SLE. Therefore, our data indicate that Cbl-b suppresses Tfh development by targeting Bcl6, and that deregulated expression of Cbl-b may play a crucial in aberrant Tfh development, thus eliciting pathogenic auto-Ab production by B cells.

Glabridin inhibits dexamethasone-induced muscle atrophy

Prevention of muscle wasting is known to contribute to improving the quality of life and extending a healthy life. Recently, we have reported that licorice flavonoid oil containing glabridin, which is a prenylated isoflavone, enhances muscle mass in mice. In this study, we investigated the prevention effect of glabridin on dexamethasone-induced muscle atrophy and clarified its mechanism in cultured myotubes and in muscle of mice. Treatment with glabridin to C2C12 myotubes inhibited dexamethasone-induced protein degradation through dexamethasone-induced expression of ubiquitin ligases, MuRF1 and Cbl-b, but not atrogin-1. Mechanistically, glabridin inhibited nuclear translocation of the glucocorticoid receptor. Glabridin directly bound to the glucocorticoid receptor, resulting in the inhibition of binding between dexamethasone and the receptor protein. Glabridin also inhibited dexamethasone-induced phosphorylation of p38 and FoxO3a, as the upstream for the induction of ubiquitin ligases in C2C12 myotubes. Moreover, the glabridin-induced inhibition of protein degradation was eliminated by knockdown of the glucocorticoid receptor, but not by p38 knockdown. These data indicated that the inhibitory mechanism of glabridin against dexamethasone-induced muscle atrophy was mainly mediated by the inhibition of binding between dexamethasone and the glucocorticoid receptor in myotubes. Oral administration of glabridin prevented dexamethasone-induced protein degradation in the tibialis anterior muscle of mice. It was confirmed that glabridin inhibited dexamethasone-induced nuclear translocation of the glucocorticoid receptor and phosphorylation of FoxO3a in the muscle of mice. These findings suggest that glabridin is an effective food ingredient for the prevention of glucocorticoid-induced skeletal muscle atrophy.

Suppressed expression of Cbl-b by NF-κB mediates icotinib resistance in EGFR-mutant non-small-cell lung cancer.

Although epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) could greatly improve the prognosis of NSCLC patients harboring activating EGFR mutations, drug resistance still remains a major obstacle to successful treatment. Our previous study found that the EGFR-TKI icotinib could upregulate the expression of Casitas-B-lineage lymphoma protein-B (Cbl-b), an E3 ubiquitin ligase. In the present study, we aimed to clarify the potential role of Cbl-b in the resistance to icotinib, and the underlying mechanisms using EGFR-mutant cell lines. We found that icotinib inhibited the proliferation of mutant-EGFR NSCLC cells (PC9 and HCC827), and upregulated the expression of Cbl-b at both the protein and mRNA levels. Cbl-b knockdown decreased the sensitivity of PC9 and HCC827 cells to icotinib, and partially restored icotinib-inhibited AKT activation in PC9 cells. On the contrary, Cbl-b overexpression could partly reverse the drug resistance in PC9 icotinib-resistant cells (PC9/IcoR). Moreover, overexpressing p65, the main member of transcription factor NF-κB family, reversed the icotinib-mediated upregulation of Cbl-b. Collectively, these data suggest that icotinib could upregulate Cbl-b mediated by NF-κB inhibition, and Cbl-b contribute to the icotinib sensitivity in EGFR-mutant NSCLC cells. This study highlights that low expression of Cbl-b might be the key obstacles in the efficacy of icotinib therapy.

Reactive oxygen species upregulate expression of muscle atrophy-associated ubiquitin ligase Cbl-b in rat L6 skeletal muscle cells.

Unloading-mediated muscle atrophy is associated with increased reactive oxygen species (ROS) production. We previously demonstrated that elevated ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b) resulted in the loss of muscle volume (Nakao R, Hirasaka K, Goto J, Ishidoh K, Yamada C, Ohno A, Okumura Y, Nonaka I, Yasutomo K, Baldwin KM, Kominami E, Higashibata A, Nagano K, Tanaka K, Yasui N, Mills EM, Takeda S, Nikawa T. Mol Cell Biol 29: 4798-4811, 2009). However, the pathological role of ROS production associated with unloading-mediated muscle atrophy still remains unknown. Here, we showed that the ROS-mediated signal transduction caused by microgravity or its simulation contributes to Cbl-b expression. In L6 myotubes, the assessment of redox status revealed that oxidized glutathione was increased under microgravity conditions, and simulated microgravity caused a burst of ROS, implicating ROS as a critical upstream mediator linking to downstream atrophic signaling. ROS generation activated the ERK1/2 early-growth response protein (Egr)1/2-Cbl-b signaling pathway, an established contributing pathway to muscle volume loss. Interestingly, antioxidant treatments such as N-acetylcysteine and TEMPOL, but not catalase, blocked the clinorotation-mediated activation of ERK1/2. The increased ROS induced transcriptional activity of Egr1 and/or Egr2 to stimulate Cbl-b expression through the ERK1/2 pathway in L6 myoblasts, since treatment with Egr1/2 siRNA and an ERK1/2 inhibitor significantly suppressed clinorotation-induced Cbl-b and Egr expression, respectively. Promoter and gel mobility shift assays revealed that Cbl-b was upregulated via an Egr consensus oxidative responsive element at -110 to -60 bp of the Cbl-b promoter. Together, this indicates that under microgravity conditions, elevated ROS may be a crucial mechanotransducer in skeletal muscle cells, regulating muscle mass through Cbl-b expression activated by the ERK-Egr signaling pathway.

C-Cbl and Cbl-b expression in skull base chordomas is associated with tumor progression and poor prognosis

Chordomas are rare, locally aggressive malignancies that are often difficult to eradicate. Surgery and radiotherapy are the first-line treatments, but the probability of local recurrence is high. According to our previous research, c-Cbl and Cbl-b have been linked to tumor progression and poor prognosis of glioma. However, their role in skull base chordomas is unclear. To clarify this issue, in the present study, we analyzed the expression of c-Cbl and Cbl-b in relation to the clinicopathological features and clinical outcome of skull base chordoma patients (n = 70). C-Cbl and Cbl-b expression was evaluated by immunohistochemistry, and a survival analysis was performed based on clinical data. We found that c-Cbl and Cbl-b were upregulated in 30 of 70 (42.9%) and 32 of 70 (45.7%) patients with skull base chordomas, respectively. A Kaplan-Meier analysis and log-rank test indicated that high c-Cbl and Cbl-b levels were significantly associated with overall survival (P = .003 and P = .008, respectively) and progression-free survival (P < .001 and P = .022, respectively). These data indicated that c-Cbl and Cbl-b expression in skull base chordomas can predict tumor invasion and poor prognosis and is therefore a potential therapeutic target for chordoma treatment.

Down-regulation of TYK2, CBLB and LMP7 genes expression in relapsing-remitting multiple sclerosis patients treated with interferon-beta

This study aimed to examine the expression of TYK2, CBLB and LMP7 genes at both mRNA and protein levels in relapsing-remitting MS (RRMS) patients in compare with healthy controls. Seventy-eight RRMS patients treated with IFNβ-1a and 79 age- and ethnic-matched healthy subjects were studied. The mRNA expression levels of TYK2, CBLB and LMP7 in PBMCs were quantified by real-time PCR and plasma concentrations of three molecules were measured by ELISA. Results were compared between patients and controls, IFNβ-responders and non-responders. Forty-nine of 78 patients were classified as IFNβ-responders and 29 cases were non-responders. Significantly down-regulated expression of TYK2, CBLB and LMP7 genes was found in the patients group versus controls (P<0.001). Decreased plasma levels of three molecules were observed in patients compared to controls (P<0.001). IFNβ-responders had significantly higher expressions for CBLB (P=0.001) and LMP7 (P=0.02) than non-responders. Also, we observed increased expressions of LMP7 (P=0.39) and CBLB (P=0.02) genes in patients under 30y and increased expression of TYK2 in patients >40years (P=0.002). Our results suggest that expression analysis of TYK2, CBLB and LMP7 genes could be useful for evaluation of T cells immunity and clinical response to IFNβ-therapy in RRMS patients.

Delphinidin prevents disuse muscle atrophy and reduces stress-related gene expression.

Delphinidin is a member of the anthocyanidin class of plant pigments. We examined the effects of delphinidin on muscle atrophy. Oral administration of delphinidin suppressed the muscle weight loss induced by mechanical unloading. Microarray analysis showed that delphinidin suppresses the upregulation of oxidative stress-related gene expression, including the expression of Cbl-b. Thus, delphinidin may prevent unloading-mediated muscle atrophy.

Clinical significance of tumor-infiltrating immune cells focusing on BTLA and Cbl-b in patients with gallbladder cancer.

The host immune system plays a significant role in tumor control, although most cancers escape immune surveillance through a variety of mechanisms. The aim of the present study was to evaluate the clinicopathological significance of a novel co-inhibitory receptor, B and T lymphocyte attenuator (BTLA), the anergy cell marker Casitas-B-lineage lymphoma protein-b (Cbl-b), and clinical implications of tumor-infiltrating immune cells in gallbladder cancer (GBC) tissues. We investigated 211 cases of GBC, 21 cases of chronic cholecystitis (CC), and 11 cases of xanthogranulomatous cholecystitis (XGC) using immunohistochemistry to detect tissue-infiltrating immune cells and their expression of BTLA and Cbl-b, and carried out correlation and survival analyses. The density of infiltrating T cells was significantly higher in CC and XGC than in GBC. The density ratio of BTLA(+) cells to CD8(+) T cells (BTLA/CD8) and that of Cbl-b(+) cells to CD8(+) T cells (Cbl-b/CD8) were significantly higher in GBC than in CC and XGC. The FOXP3/CD4, BTLA/CD8, and Cbl-b/CD8 ratios were significantly correlated with each other, and also with malignant phenotypes. Survival analyses revealed that a lower density of tumor-infiltrating CD8(+) cells, and higher Foxp3/CD4, BTLA/CD8, and Cbl-b/CD8 ratios were significantly associated with shorter overall survival and disease-free survival in GBC patients. Multivariate analyses showed that M factor, perineural invasion, BTLA/CD8, and Cbl-b/CD8 were closely associated with shorter overall survival. These findings suggest that higher ratios of BTLA/CD8 and Cbl-b/CD8 are independent indicators of unfavorable outcome in GBC patients, and that upregulation of BTLA in cancer tissues is involved in inhibition of antitumor immunity.

Cbl-b-regulated extracellular signal-regulated kinase signaling is involved in the shikonin-induced apoptosis of lung cancer cells in vitro.

Shikonin (SK), a naturally occurring naphthoquinone, exhibits antitumor activity. However, its precise mechanisms of action are unknown. In the present study, the effects of SK on NCI-H460 human lung cancer cells were investigated. It was found that SK reduced cell viability and induced apoptosis in the NCI-H460 cells. Additionally, SK inhibited extracellular signal-regulated kinase (ERK) activity, which indicates that inhibition of the ERK pathway is probably one of the mechanisms by which SK induced NCI-H460 cell apoptosis. The expression of Cbl-b was significantly increased by treatment with SK for 4 h, and gradually increased to a maximal level at 24 h; the time taken for the upregulation of Cbl-b protein was in accordance to that required for the downregulation of phospho (p)-ERK protein. The Cbl inhibitor Ps341 reversed the SK-induced downregulation of p-ERK and apoptosis of NCI-H460 cells. These results indicate that Cbl-b potentiates the apoptotic action of SK by inhibiting the ERK pathway in lung cancer cells.

Clinical significance of expression of c-Cbl and Cbl-b in gastric cancer

Clinical significance of expression of c-Cbl and Cbl-b in gastric cancer