Sncg, Mybpc1, and Parm1 Classify subpopulations of VIP-expressing interneurons in layers 2/3 of the somatosensory cortex.

Neocortical vasoactive intestinal polypeptide-expressing (VIP+) interneurons display highly diverse morpho-electrophysiological and molecular properties. To begin to understand the function of VIP+ interneurons in cortical circuits, they must be clearly and comprehensively classified into distinct subpopulations based on specific molecular markers. Here, we utilized patch-clamp RT-PCR (Patch-PCR) to simultaneously obtain the morpho-electric properties and mRNA profiles of 155 VIP+ interneurons in layers 2 and 3 (L2/3) of the mouse somatosensory cortex. Using an unsupervised clustering method, we identified 3 electrophysiological types (E-types) and 2 morphological types (M-types) of VIP+ interneurons. Joint clustering based on the combined electrophysiological and morphological features resulted in 3 morpho-electric types (ME-types). More importantly, we found these 3 ME-types expressed distinct marker genes: ~94% of Sncg+ cells were ME-type 1, 100% of Mybpc1+ cells were ME-type 2, and ~78% of Parm1+ were ME-type 3. By clarifying the properties of subpopulations of cortical L2/3 VIP+ interneurons, this study establishes a basis for future investigations aiming to elucidate their physiological roles.

A positive feedback circuit between RN7SK snRNA and m6A readers is essential for tumorigenesis.

N6-Methyladenosine (m6A) RNA modification, methylation at the N6 position of adenosine, plays critical roles in tumorigenesis. m6A readers recognize m6A modifications and thus act as key executors for the biological consequences of RNA methylation. However, knowledge about the regulatory mechanism(s) of m6A readers is extremely limited. In this study, RN7SK was identified as a small nuclear RNA that interacts with m6A readers. m6A readers recognized and facilitated secondary structure formation of m6A-modified RN7SK, which in turn prevented m6A reader mRNA degradation from exonucleases. Thus, a positive feedback circuit between RN7SK and m6A readers is established in tumor cells. From findings on the interaction with RN7SK, new m6A readers, such as EWS RNA binding protein 1 (EWSR1) and KH RNA binding domain containing, signal transduction-associated 1 (KHDRBS1), were identified and shown to boost Wnt/ß-catenin signaling and tumorigenesis by suppressing translation of Cullin1 (CUL1). Moreover, several Food and Drug Administration-approved small molecules were demonstrated to reduce RN7SK expression and inhibit tumorigenesis. Together, these findings reveal a common regulatory mechanism of m6A readers and indicate that targeting RN7SK has strong potential for tumor treatment.

RBM4 inhibits the growth of clear cell renal cell carcinoma by enhancing the stability of p53 mRNA.

RBM4 has been reported as a tumor suppressor gene in cancers, including lung cancer, colon cancer and gastric cancer. However, the role of RBM4 in clear cell renal cell carcinoma (ccRCC) remains unclear. Therefore, the present study investigated the expression and biological function of RBM4 in ccRCC. Analysis of the differential expression of RBM4 and its relationship with clinicopathological features using ccRCC samples data from TCGA database deminstrated that RBM4 expression in tumor samples of ccRCC was lower than that in normal samples, and RBM4 expression was closely related to the survival time of patients. RBM4 overexpression (RBM4-oe) cell lines were constructed to investigate the effect of RBM4 on biological function using CCK-8, EdU, flow cytometry and wound-healing assays. In addition, the regulatory effect of RBM4 on signaling pathways was investigated by GSEA and WB assays. RBM4-oe significantly reduced the proliferation of ccRCC cells by controlling the p53 signaling pathway, inhibited cell cycle progression and promoted apoptosis. In addition, RBM4-oe suppressed the migration and invasion of cells by EMT. Mechanistically, RBM4-oe facilitated the activity of the p53 signaling pathway by enhancing the stability of p53 mRNA. Finally, RBM4-oe markedly inhibited the growth of tumors formed with 786-O cells in vivo. In summary, there findings suggeated that RBM4 inhibits the progression of ccRCC by promoting p53 signaling pathway activity by enhancing the stability of p53 mRNA, suggesting that RBM4 may be a potential target for the treatment of patients.

Ratiometric electrochemical OR gate assay for NSCLC-derived exosomes.

Non-small cell lung cancer (NSCLC) is the most common pathological type of LC and ranks as the leading cause of cancer deaths. Circulating exosomes have emerged as a valuable biomarker for the diagnosis of NSCLC, while the performance of current electrochemical assays for exosome detection is constrained by unsatisfactory sensitivity and specificity. Here we integrated a ratiometric biosensor with an OR logic gate to form an assay for surface protein profiling of exosomes from clinical serum samples. By using the specific aptamers for recognition of clinically validated biomarkers (EpCAM and CEA), the assay enabled ultrasensitive detection of trace levels of NSCLC-derived exosomes in complex serum samples (15.1 particles µL-1 within a linear range of 102-108 particles µL-1). The assay outperformed the analysis of six serum biomarkers for the accurate diagnosis, staging, and prognosis of NSCLC, displaying a diagnostic sensitivity of 93.3% even at an early stage (Stage I). The assay provides an advanced tool for exosome quantification and facilitates exosome-based liquid biopsies for cancer management in clinics.

A Versatile Electrochemical Biosensor for the Detection of Circulating MicroRNA toward Non-Small Cell Lung Cancer Diagnosis.

Circulating microRNAs (miRNAs) can be used as noninvasive biomarkers and are also found circulating in body fluids such as blood. Dysregulated miRNA expression is associated with many diseases, including non-small cell lung cancer (NSCLC), and the miRNA assay is helpful in cancer diagnosis, prognosis, and monitoring. In this work, a versatile electrochemical biosensing system is developed for miRNA detection by DNAzyme-cleavage cycling amplification and hybridization chain reaction (HCR) amplification. With cleavage by Mn2+ targeted DNAzyme, DNA-walker can move along the predesigned DNA tracks and contribute to the transduction and enhancement of signals. For the electrochemical process, the formation of multiple G-quadruplex-incorporated long double-stranded DNA (dsDNA/G-quadruplex) structures is triggered through HCR amplification. The introduction of G-quadruplex allows sensitive measurement of miRNA down to 5.68 fM with good specificity. Furthermore, by profiling miRNA in the NSCLC cohort, this designed strategy shows high efficiency (area under the curve (AUC) of 0.879 using receiver operating characteristic (ROC) analysis) with the sensitivity of 80.0% for NSCLC early diagnosis (stage I). For the discrimination of NSCLC and benign disease, the assay displays an AUC of 0.907, superior to six clinically-acceptable protein tumor markers. Therefore, this platform holds promise in clinical application toward NSCLC diagnosis and prognosis.

Exosomes-transmitted miR-7 reverses gefitinib resistance by targeting YAP in non-small-cell lung cancer.

Epidermal growth factor receptor (EGFR) T790M mutation act as the dominant resistance mechanism to first and second generations tyrosine kinase inhibitors (TKIs), the roles of miR-7 in the development of T790M mutation are largely unknown. Here, we confirmed that the level of miR-7 was significantly higher in the gefitinib sensitivity PC9 cells compared to gefitinib resistance H1975 cells, and miR-7 overexpression promoted the apoptosis of H1975 cells by gefitinib treatment. Furthermore, we found that exosomes could transfer miR-7 mimics from PC9 cells to H1975 cells, which reversed gefitinib resistance through binding to YAP, and altered H1975 cells resistance phenotype in vitro. In addition, we suppressed exosomal miR-7 by GW4869, increasing PC9 cells chemoresistance to gefitinib treatment in vivo. Of note, we detected that miR-7 was significantly higher in serum exosomes from healthy controls than from patients with lung carcinoma, and high miR-7 expression was associated with strong response to lung carcinoma patients receiving gefitinib treatment, as well as a longer survival. Therefore, exosomal miR-7 can act as a potential biomarker and therapeutic target for EGFR T79M resistance mutations.

The biological functions and clinical applications of exosomes in lung cancer.

Lung cancer remains the leading cause of cancer-related death worldwide, and the high incidence rates are worrisome. Exosomes are a class of extracellular vesicles secreted by most cells, including RNAs, proteins and lipids. Exosomes can mediate cell-to-cell communication in both physiologic and pathologic processes. Accumulated evidences show that cancer-derived exosomes aid in the recruitment and reprogramming of constituents correlated with tumor microenvironment. Furthermore, exosome-based clinical trials have been completed in advanced lung cancer patients. In this review, we discuss the roles of exosomes in a lung cancer microenvironment, such as its participation in lung cancer initiation, progression and metastasis as well as being involved in angiogenesis, epithelial-mesenchymal transition (EMT), immune escape, and drug resistance. In addition, we focus on the potential of exosomes as diagnostic and prognostic biomarkers in lung cancer, as well as the challenges faced by and advantages of exosomes as drug delivery vehicles and in exosome-based immunotherapy.

Neonatal CX26 removal impairs neocortical development and leads to elevated anxiety.

Electrical coupling between excitatory neurons in the neocortex is developmentally regulated. It is initially prominent but eliminated at later developmental stages when chemical synapses emerge. However, it remains largely unclear whether early electrical coupling networks broadly contribute to neocortical circuit formation and animal behavior. Here, we report that neonatal electrical coupling between neocortical excitatory neurons is critical for proper neuronal development, synapse formation, and animal behavior. Conditional deletion of Connexin 26 (CX26) in the superficial layer excitatory neurons of the mouse neocortex around birth significantly reduces spontaneous firing activity and the frequency and size of spontaneous network oscillations at postnatal day 5-6. Moreover, CX26-conditional knockout (CX26-cKO) neurons tend to have simpler dendritic trees and lower spine density compared with wild-type neurons. Importantly, early, but not late, postnatal deletion of CX26, decreases the frequency of miniature excitatory postsynaptic currents (mEPSCs) in both young and adult mice, whereas miniature inhibitory postsynaptic currents (mIPSCs) were unaffected. Furthermore, CX26-cKO mice exhibit increased anxiety-related behavior. These results suggest that electrical coupling between excitatory neurons at early postnatal stages is a critical step for neocortical development and function.

Hyperselective neurectomy in the treatment of elbow and wrist spasticity: an anatomical study and incision design.

OBJECTIVE: Hyperselective neurectomy is used to treat spastic arm paralysis. The aim of the study was to analyze the nerve branching patterns of elbow and wrist flexors/pronator to inform hyperselective neurectomy approached. METHODS: Eighteen upper extremities of fresh cadaver specimen were dissected. The number of motor branches from the musculocutaneous nerve to biceps brachii and brachialis, median nerve to pronator teres, flexor carpi radialis and ulnar nerve to flexor carpi ulnaris were counted. The origin site of each primary motor branch was documented. RESULTS: Either biceps or brachialis was innervated by one or two primary motor branches. Pronator teres was innervated by one to three motor trunks and the pattern for flexor carpi radialis was a common trunk with other branches. The origin of the biceps and brachialis nerve trunk was located approximately 30% to 60% of the length of the arm. The median nerve branched to pronator teres and flexor carpi radialis at the region about 34mm (SD 18.8mm) above and 50mm (SD 14.9mm) below the medial epicondyle. Flexor carpi ulnaris was innervated by one to three motor trunks and the mean distance from the medial epicondyle to the origin of flexor carpi ulnaris nerve on ulnar nerve was 18.7 mm (SD 6.5mm). CONCLUSION: Primary motor branches to elbow flexors, wrist flexors and pronators were various, while the regions of their origins were relatively settled. It was recommended the incisions be designed according to the location of the primary motor trunks.

Exosomes in hepatocellular carcinoma: a new horizon.

Exosomes are a class of extracellular vesicles released by multiple cells types including tumor cells, with a size range of 30-100 nm and a lipid bilayer membrane. Recently, the role of exosomes in cell-to-cell communication has been extensively studied, showed that exosomes can deliver their functional RNAs and proteins to recipient cells, impacting transcription and translation of recipient cells. Emerging evidence suggests that hepatocellular carcinoma (HCC) cell-derived exosomes can construct a fertile environment to support HCC cells proliferation, grow, invasion and metastasis, development of drug resistance. Circulating exosomes can be used as noninvasive biomarkers for early diagnosis, moreover as drug delivery vehicles, provide new insights into the treatment of HCC.

No Need to Routinely Remove Titanium Implants for Maxillofacial Fractures.

PURPOSE: Titanium implants are typically used to fix maxillofacial fractures and their routine removal is a controversial topic in maxillofacial surgery. This study aimed to estimate the removal rate and risk factors associated with removal. MATERIALS AND METHODS: The authors designed and implemented a retrospective study. Adult patients who underwent open reduction and internal fixation with titanium implants for maxillofacial fractures were included and those who returned for implant removal were identified from January 2007 to December 2016. The predictor variables were gender, age, preoperative infection, injury time, trauma cause, and fracture site. The primary outcome variable was removal of titanium implants. Descriptive and bivariate statistics were computed. Kaplan-Meier survival methods were used to estimate rate of removal. Univariate and multivariate Cox proportional hazards models were used to identify risk factors associated with removal. RESULTS: Of 2,325 patients (1,890 men and 435 women; average age, ∼35.49 yr) registered in this study, 163 (7.01%) had their titanium implants removed and 1-, 2-, and 10-year removal rates were 3, 7, and 8%, respectively. The risk factors most closely associated with removal were preoperative infection, injury by a blow from an object, obsolete fracture, and female gender. CONCLUSIONS: Routinely removing titanium implants in patients with maxillofacial fracture is not necessary. When the risk factors listed earlier are present in these patients, follow-up should be scheduled more frequently.

Bufalin inhibits cell proliferation and migration of hepatocellular carcinoma cells via APOBEC3F induced intestinal immune network for IgA production signaling pathway.

OBJECTIVE: This study aimed to evaluate functions of APOBEC3F gene in biological process of hepatocellular carcinoma (HCC) and anti-tumor mechanisms of bufalin. METHODS: Effect of APOBEC3F and bufalin on cell proliferation and migration abilities were evaluated by CCK-8, wounding healing tests and transwell assays in SK-Hep1 and Bel-7404 cells. Bioinformatic analysis were also used to compare APOBEC3F expression levels, detect coexpressed genes and enrichment of pathways. RESULTS: APOBEC3F was overexpressed in tumor tissues compared to adjacent tissues in HCC patients. And, APOBEC3F promotes cell proliferation and migration in SK-Hep1 and Bel-7404 cells. Bufalin inhibits cell proliferation and migration and reduces APOBEC3F expression. GO and KEGG enrichment of APOBEC3F-coexpressed genes revealed that APOBEC3F might active intestinal immune network for IgA production signaling pathway, leading to malignant biological behaviors of HCC cells. Additionally, siAPOBEC3F could decrease pIgR, CCR9, CCR10 and CXCR4 protein levels. And, bufalin inhibits the pIgR, CCR9, CCR10 and CXCR4 protein expressions. CONCLUSIONS: Bufalin inhibits cell proliferation and migration of HCC cells via APOBEC3F induced intestinal immune network for IgA production signaling pathway.

Preferential electrical coupling regulates neocortical lineage-dependent microcircuit assembly.

Radial glial cells are the primary neural progenitor cells in the developing neocortex. Consecutive asymmetric divisions of individual radial glial progenitor cells produce a number of sister excitatory neurons that migrate along the elongated radial glial fibre, resulting in the formation of ontogenetic columns. Moreover, sister excitatory neurons in ontogenetic columns preferentially develop specific chemical synapses with each other rather than with nearby non-siblings. Although these findings provide crucial insight into the emergence of functional columns in the neocortex, little is known about the basis of this lineage-dependent assembly of excitatory neuron microcircuits at single-cell resolution. Here we show that transient electrical coupling between radially aligned sister excitatory neurons regulates the subsequent formation of specific chemical synapses in the neocortex. Multiple-electrode whole-cell recordings showed that sister excitatory neurons preferentially form strong electrical coupling with each other rather than with adjacent non-sister excitatory neurons during early postnatal stages. This preferential coupling allows selective electrical communication between sister excitatory neurons, promoting their action potential generation and synchronous firing. Interestingly, although this electrical communication largely disappears before the appearance of chemical synapses, blockade of the electrical communication impairs the subsequent formation of specific chemical synapses between sister excitatory neurons in ontogenetic columns. These results suggest a strong link between lineage-dependent transient electrical coupling and the assembly of precise excitatory neuron microcircuits in the neocortex.

Long non-coding RNA urothelial carcinoma-associated 1 as a tumor biomarker for the diagnosis of urinary bladder cancer.

To investigate the diagnostic value of urothelial carcinoma-associated 1 as a urine biomarker in urinary bladder cancer patients by performing a comprehensive meta-analysis. A comprehensive literature search was conducted by the databases PubMed, Embase, Cochrane Library, China Knowledge Resource Integrated, and Web of Science. The quality of eligible studies was scored with the Quality Assessment of Diagnostic Accuracy Studies. The bivariate meta-analysis model was used to pool the sensitivity, specificity, likelihood ratio, and diagnostic odds ratio. Receiver operating characteristic curves and hierarchical summary receiver operating characteristic models were employed to check the overall test performance in this meta-analysis. Seven publications involving 678 patients and 563 controls were included in this meta-analysis. The pooled sensitivity was 0.84 (95% confidence interval: 0.80-0.88), specificity was 0.87 (95% confidence interval: 0.75-0.94), positive likelihood ratio was 6.5 (95% confidence interval: 3.10-13.62), negative likelihood ratio was 0.18 (95% confidence interval: 0.13-0.25), and diagnostic odds ratio was 36 (95% confidence interval: 13-99). The area under the summary receiver operating characteristic curve was 0.89 (95% confidence interval: 0.86-0.91). Our results indicated that urothelial carcinoma-associated 1 was a potential diagnostic biomarker with good specificity and sensitivity in urinary bladder cancer. Further prospective studies with larger cohorts are necessary to evaluate the diagnostic accuracy of urothelial carcinoma-associated 1 for urinary bladder cancer.

Sirtuin 6 plays an oncogenic role and induces cell autophagy in esophageal cancer cells.

Sirtuin 6, a member of sirtuin family, is generally regarded as a tumor suppressor as it participates in suppressing hypoxia-inducible factor 1α and MYC transcription activity by deacetylating H3K9 (histone H3 lysine 9) and H3K56 (histone H3 lysine) at promoters of target genes, leading to the aerobic glycolysis inhibition and cell growth suppression. However, its expression has recently been reported to be highly elevated in a series of tumors, including prostate cancer, breast cancer, and non-small cell lung cancer, indicating that sirtuin 6 plays dual roles in tumorigenicity in a cell/tumor type-specific manner. To our knowledge, the biological roles of sirtuin 6 in esophageal cancer cells have still been underestimated. In the study, data from quantitative reverse transcriptase polymerase chain reaction-based assays and immunohistochemical assays revealed that sirtuin 6 was remarkably overexpressed in esophageal squamous tumor tissues. Moreover, its upregulation was closely related with clinical features, such as gender, pathology, tumor-node-metastasis, and cell differentiation. Subsequently, the biological tests showed that it promoted cell proliferation and induced the expression of Bcl2, a key anti-apoptotic factor, in esophageal carcinoma cells. Moreover, using the ratio of LC3II/I, a widely recognized autophagy biomarker, we showed that it apparently induced cell autophagy, which was further confirmed by the autophagy flux assays. In addition, results from western blotting assays and immunoprecipitation assays displayed that sirtuin 6 specifically interacted with ULK1 and positively regulated its activity by inhibiting its upstream factor mammalian target of rapamycin activity. In summary, our studies shed insights into the crucial functions of sirtuin 6 in esophageal carcinoma cells and provide evidence supporting sirtuin 6-based personalized therapies in esophageal carcinoma cell patients.

Cluster of differentiation 166 (CD166) regulated by phosphatidylinositide 3-Kinase (PI3K)/AKT signaling to exert its anti-apoptotic role via yes-associated protein (YAP) in liver cancer.

Cluster of differentiation 166 (CD166 or Alcam) is a cell surface molecule that can be greatly induced in liver cancer cells after serum deprivation, suggesting its role in influencing cell survival. However, whether and how CD166 acts as an anti-apoptotic regulator needs to be further investigated. Here, we report that gene silencing of CD166 promoted apoptosis via down-regulation of Bcl-2 in liver cancer cells. PI3K/AKT signaling was found to up-regulate CD166 expression independently of transcription. We also revealed that CD166 promoted both AKT expression and activity, thus providing a novel positive regulatory feedback between PI3K/AKT signaling and CD166. Moreover, Yes-associated protein (YAP) was identified as a CD166 downstream effecter, which can partly rescue CD166 knockdown-induced apoptosis and reduced in vivo cancer cell growth. Mechanically, CD166 modulated YAP expression and activity through at least two different ways, transcriptional regulation of YAP through cAMP-response element-binding protein and post-transcriptional control of YAP stability through inhibition to AMOT130. We also showed that CD9 enhanced CD166-mediated regulation of YAP via a mechanism involving facilitating CD166-CD166 homophilic interaction. Tissue microarray analysis revealed that CD166 and YAP were up-regulated and closely correlated in liver cancer samples, demonstrating the importance of their relationship. Taken together, this work summarizes a novel link between CD166 and YAP, explores the interplay among related important signaling pathways, and may lead to more effective therapeutic strategies for liver cancer.

Specific synapses develop preferentially among sister excitatory neurons in the neocortex.

Neurons in the mammalian neocortex are organized into functional columns. Within a column, highly specific synaptic connections are formed to ensure that similar physiological properties are shared by neuron ensembles spanning from the pia to the white matter. Recent studies indicate that synaptic connectivity in the neocortex is sparse and highly specific to allow even adjacent neurons to convey information independently. How this fine-scale microcircuit is constructed to create a functional columnar architecture at the level of individual neurons largely remains a mystery. Here we investigate whether radial clones of excitatory neurons arising from the same mother cell in the developing neocortex serve as a substrate for the formation of this highly specific microcircuit. We labelled ontogenetic radial clones of excitatory neurons in the mouse neocortex by in utero intraventricular injection of enhanced green fluorescent protein (EGFP)-expressing retroviruses around the onset of the peak phase of neocortical neurogenesis. Multiple-electrode whole-cell recordings were performed to probe synapse formation among these EGFP-labelled sister excitatory neurons in radial clones and the adjacent non-siblings during postnatal stages. We found that radially aligned sister excitatory neurons have a propensity for developing unidirectional chemical synapses with each other rather than with neighbouring non-siblings. Moreover, these synaptic connections display the same interlaminar directional preference as those observed in the mature neocortex. These results indicate that specific microcircuits develop preferentially within ontogenetic radial clones of excitatory neurons in the developing neocortex and contribute to the emergence of functional columnar microarchitectures in the mature neocortex.

Development of layer 1 neurons in the mouse neocortex.

Layer 1 of the neocortex harbors a unique group of neurons that play crucial roles in synaptic integration and information processing. Although extensive studies have characterized the properties of layer 1 neurons in the mature neocortex, it remains unclear how these neurons progressively acquire their distinct morphological, neurochemical, and physiological traits. In this study, we systematically examined the dynamic development of Cajal-Retzius cells and γ-aminobutyric acid (GABA)-ergic interneurons in layer 1 during the first 2 postnatal weeks. Cajal-Retzius cells underwent morphological degeneration after birth and gradually disappeared from layer 1. The majority of GABAergic interneurons showed clear expression of at least 1 of the 6 distinct neurochemical markers, including Reelin, GABA-A receptor subunit delta (GABAARδ), neuropeptide Y, vasoactive intestinal peptide (VIP), calretinin, and somatostatin from postnatal day 8. Furthermore, according to firing pattern, layer 1 interneurons can be divided into 2 groups: late-spiking (LS) and burst-spiking (BS) neurons. LS neurons preferentially expressed GABAARδ, whereas BS neurons preferentially expressed VIP. Interestingly, both LS and BS neurons exhibited a rapid electrophysiological and morphological development during the first postnatal week. Our results provide new insights into the molecular, morphological, and functional developments of the neurons in layer 1 of the neocortex.

Impaired phosphorylation and ubiquitination by p70 S6 kinase (p70S6K) and Smad ubiquitination regulatory factor 1 (Smurf1) promote tribbles homolog 2 (TRIB2) stability and carcinogenic property in liver cancer.

Tribbles homolog 2 (TRIB2) is critical for both solid and non-solid malignancies. Recently, TRIB2 was identified as a liver cancer-specific Wnt/ß-catenin signaling downstream target and is functionally important for liver cancer cell survival and transformation. TRIB2 functions as a protein that interacts with E3 ubiquitin ligases and thereby modulates protein stability of downstream effectors. However, the regulation underlying TRIB2 protein stability per se has not yet been reported. In this study, we found that TRIB2 was up-regulated and exhibited high stability in liver cancer cells compared with other cells. We performed a structure-function analysis of TRIB2 and identified a domain (amino acids 1-5) at the N terminus that interacted with the E3 ubiquitin ligase Smurf1 and was critical for protein stability. Deletion of this domain extended TRIB2 half-life time accompanied with a more significant malignant property compared with wild type TRIB2. Furthermore, Smurf1-mediated ubiquitination required phosphorylation of TRIB2 by p70 S6 kinase (p70S6K) via another domain (amino acids 69-85) that is also essential for correct TRIB2 subcellular localization. Mutation of Ser-83 diminished p70S6K-induced phosphorylation of TRIB2. Moreover, the high stability of TRIB2 may be due to the fact that both p70S6K and Smurf1 were down-regulated and negatively correlated with TRIB2 expression in both liver cancer tissues and established liver cancer cell lines. Taken together, impaired phosphorylation and ubiquitination by p70S6K and Smurf1 increase the protein stability of TRIB2 in liver cancer and thus may be helpful in the development of diagnosis and treatment strategies against this malignant disease.

Cluster of differentiation 166 (CD166) regulates cluster of differentiation (CD44) via NF-κB in liver cancer cell line Bel-7402.

Cluster of differentiation 166 (CD166) is critical for liver cancer cell survival. Our previously study demonstrated that CD166 exerts its anti-apoptotic role through interaction with YAP in liver cancer. However, the interaction between CD166 and other cell surface molecules remains unclear in liver cancer cells. In the current study, we found that both mRNA and protein of CD44 expression was significantly inhibited by knocking-down CD166. Moreover, CD166 affected-CD44 expression is dependent of transcription via blocking NF-κB pathway. On the contrary, CD44 promoted up-regulation of CD166 mRNA and protein. And it may be through E3 ubiquitin ligases COP1 and UBC3 to regulate CD166 protein degradation. Collectively, these results suggest that CD166 and CD44 play important roles in liver cancer development. Therefore, CD166 may develop as a potential therapeutic molecule target for the treatment of liver cancer.