BET inhibition triggers antitumor immunity by enhancing MHC class I expression in head and neck squamous cell carcinoma.

BET inhibition has been shown to have a promising antitumor effect in multiple tumors. However, the impact of BET inhibition on antitumor immunity was still not well documented in HNSCC. In this study, we aim to assess the functional role of BET inhibition in antitumor immunity and clarify its mechanism. We show that BRD4 is highly expressed in HNSCC and inversely correlated with the infiltration of CD8+ T cells. BET inhibition potentiates CD8+ T cell-based antitumor immunity in vitro and in vivo. Mechanistically, BRD4 acts as a transcriptional suppressor and represses the expression of MHC class I molecules by recruiting G9a. Pharmacological inhibition or genetic depletion of BRD4 potently increases the expression of MHC class I molecules in the absence and presence of IFN-γ. Moreover, compared to PD-1 blocking antibody treatment or JQ1 treatment individually, the combination of BET inhibition with anti-PD-1 antibody treatment significantly enhances the antitumor response in HNSCC. Taken together, our data unveil a novel mechanism by which BET inhibition potentiates antitumor immunity via promoting the expression of MHC class I molecules and provides a rationale for the combination of ICBs with BET inhibitors for HNSCC treatment.

The Accuracy of Urinary TIMP-2 and IGFBP7 for the Diagnosis of Cardiac Surgery-Associated Acute Kidney Injury: A Systematic Review and Meta-Analysis.

BACKGROUND: Tissue inhibitor of metalloproteinase 2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7) are recent promising markers for identification of cardiac surgery-associated acute kidney injury (CSA-AKI). The aim of this study was systematically and quantitatively to evaluate the accuracy of urinary TIMP-2 and IGFBP7 for the diagnosis of CSA-AKI. METHODS: Three databases including PubMed, ISI web of knowledge, and Embase were systematically searched from inception to March 2018. Two investigators conducted the processes of literature search study selection, data extraction, and quality evaluation independently. Meta-DiSc and STATA were used for all statistical analyses. RESULTS: A total of 8 studies comprising 552 patients were included in this meta-analysis. Pooled sensitivity and specificity with corresponding 95% confidence intervals (CIs) were 0.79 (95% CI, 0.71-0.86, I 2 = 74.2%) and 0.76 (95% CI, 0.72-0.80, I 2 = 80.8%), respectively. Pooled positive likelihood ratio (LR), negative LR, and diagnostic odds ratio were 3.49 (95% CI, 2.44-5.00, I 2 = 61.5%), 0.31(95% CI, 0.19-0.51, I 2 = 51.8%), and 14.89 (95% CI, 7.31-30.32, I 2 = 27.9%), respectively. The area under curve estimated by summary receiver operating characteristic was 0.868 (standard error [SE] 0.032) with a Q* value of 0.799 (SE 0.032). Sensitivity analysis demonstrated that one study notably affected the stability of pooled results. One of the subgroups investigated-AKI threshold-could account for partial heterogeneity. CONCLUSION: Urinary TIMP-2 and IGFBP7 is a helpful biomarker for early diagnosis of CSA-AKI. And, the potential of this biomarker with a broader spectrum of clinical settings may be the focus of future studies.

Early extubation after thymectomy is good for the patients with myasthenia gravis.

OBJECTIVES: Patients with myasthenia gravis (MG) often benefit from thymectomy, but the optimal timing of extubation following thymectomy in these patients remains unknown. This study of MG patients compared the effect of early and late extubation following thymectomy on clinical outcome. METHODS: We performed a study of data from 96 patients with MG who received thymectomy procedures, followed by early (< 6 h) or late (> 6 h) extubation, at our institution between October 2011 and November 2017. Patient clinical and demographic characteristics, preoperative data, and postoperative clinical outcomes were analyzed. Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study. RESULTS: The patients in the early extubation group (n = 53) and late extubation group (n = 43) had similar preoperative clinical and demographic characteristics. However, the early extubation group had a significantly longer duration of MG (24 months vs. 12 months, P < 0.013) and a lower incidence of reintubation (11.3% vs. 37.2%, P = 0.003). Postoperative pulmonary infection was significantly more common in the late extubation group (39.5% vs. 11.3%, P = 0.001; adjusted odds ratio = 6.94, 95% CI 1.24-38.97). Also, patients in the late extubation group had a longer duration of ICU stay (6.4 ± 4.0 h vs. 4.3 ± 1.8 h; P = 0.003) and had a longer adjusted duration of ICU stay by 0.93 days (95% CI 0.02-1.85). CONCLUSIONS: Our analysis of patients with MG who received thymectomy procedures indicated that early extubation was associated with improved clinical outcomes, in particular with reduced risk of postoperative pulmonary infection and reduced ICU stay.

Activation of nuclear factor κB pathway and downstream targets survivin and livin by SHARPIN contributes to the progression and metastasis of prostate cancer.

BACKGROUND: Nuclear factor κB (NFκB) signaling is strongly associated with tumor progression, and studies have shown that SHANK-associated RH domain interacting protein (SHARPIN) is crucial for NFκB pathway activation. However, the expression and functions of SHARPIN in prostate cancer (PCa) have not yet been defined. METHODS: The expression of SHARPIN in PCa cell lines and tissues was evaluated with western blotting, quantitative real-time polymerase chain reaction, and immunohistochemistry. After SHARPIN was silenced in the PCa cell lines, western blots were used to confirm that SHARPIN physically associated with components of the NFκB pathway and the downstream targets (survivin and livin). The functions of SHARPIN in cell proliferation, migration, and invasion in vitro were measured with 5-(3-carboxymethoxyphenyl)-2-(4,5-dimenthylthiazoly)-3-(4-sulfophenyl)tetrazolium, inner salt (MTS), Transwell, and invasion assays, respectively. Flow cytometry was employed to evaluate cell apoptosis. Furthermore, tumorigenesis in vivo was examined with tumorigenicity assays. RESULTS: SHARPIN expression was upregulated in PCa cell lines and tissues. The knockdown of SHARPIN or incubation with Bay 11-7082 (an NFκB inhibitor) led to dramatically decreased levels of phosphorylated IκBα and phosphorylated p65 in comparison with the control group. Downregulation of survivin and livin due to SHARPIN inhibition was attributable to transcriptional repression (P < .05). Decreases in cell viability, migration, invasion, and survival with a higher sensitivity to docetaxel in vitro and with repressed tumorigenesis in vivo were observed upon SHARPIN silencing, and this was consistent with the results from inhibition of the NFκB pathway and its downstream targets. CONCLUSION: The current study demonstrates that overexpression of SHARPIN promotes activation of the NFκB pathway and downstream targets survivin and livin, which potentially contributes to PCa development.

CD276-dependent efferocytosis by tumor-associated macrophages promotes immune evasion in bladder cancer.

Interplay between innate and adaptive immune cells is important for the antitumor immune response. However, the tumor microenvironment may turn immune suppressive, and tumor associated macrophages are playing a role in this transition. Here, we show that CD276, expressed on tumor-associated macrophages (TAM), play a role in diminishing the immune response against tumors. Using a model of tumors induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in BLCA male mice we show that genetic ablation of CD276 in TAMs blocks efferocytosis and enhances the expression of the major histocompatibility complex class II (MHCII) of TAMs. This in turn increases CD4 + and cytotoxic CD8 + T cell infiltration of the tumor. Combined single cell RNA sequencing and functional experiments reveal that CD276 activates the lysosomal signaling pathway and the transcription factor JUN to regulate the expression of AXL and MerTK, resulting in enhanced efferocytosis in TAMs. Proving the principle, we show that simultaneous blockade of CD276 and PD-1 restrain tumor growth better than any of the components as a single intervention. Taken together, our study supports a role for CD276 in efferocytosis by TAMs, which is potentially targetable for combination immune therapy.

SALL4 correlates with proliferation, metastasis, and poor prognosis in prostate cancer by affecting MAPK pathway.

BACKGROUND: The mechanism involved in prostate cancer (PCa) metastasis is still poorly understood, and several oncogenes are known to regulate this process. However, the role of spalt-like transcription factor 4 (SALL4) in PCa metastasis remains unclear. METHODS: We performed RNA-sequencing to compare the mRNA expression profiles of seven localized PCa tissues and six metastatic PCa tissues. SALL4 was then identified and compared in the localized PCa and metastatic PCa. Immunohistochemical studies, qRT-PCR, and Western blot were performed to analyze the expression of SALL4 in PCa patients and cell lines. SALL4 expression and its relevance to clinical traits and prognosis were further explored in the TCGA database and in our 68 clinical samples. Subsequently, we knocked down SALL4 in DU145 and PC3 cells and performed a series of functional assays to explore the effect of SALL4 on PCa progression. Finally, protein levels of SALL4 and core components of the MAPK pathway were measured by Western blot, and cells were treated with PD0325901 to observe proliferation and metastasis. RESULTS: Significantly higher expression of SALL4 was found in metastatic PCa than in localized PCa. In addition, high SALL4 expression was significantly associated with high pathological T stage, N stage, Gleason score, and poor disease-free survival in TCGA database and in our clinical samples. Functional studies indicated that knockdown of SALL4 in DU145 and PC3 inhibited proliferation, migration, and angiogenesis. Furthermore, the ERK and P38 protein phosphorylation significantly reduced after knockdown of SALL4 in DU145 and PC3, indicating the inactivation of the MAPK signaling pathway. Finally, the proliferation and migration ability of DU145 and PC3 cells were significantly decreased after PD0325901 treatment. CONCLUSIONS: SALL4 predicts unfavorable outcome and is closely associated with PCa progression, suggesting that SALL4 may be a promising prognostic marker and potential therapeutic target for PCa.

NAT10-mediated mRNA N4-acetylcytidine modification promotes bladder cancer progression.

BACKGROUND: Dysregulation of the epitranscriptome causes abnormal expression of oncogenes in the tumorigenic process. Previous studies have shown that NAT10 can regulate mRNA translation efficiency through RNA acetylation. However, the role of NAT10-mediated acetylation modification in bladder cancer remains elusive. METHODS: The clinical value of NAT10 was estimated according to NAT10 expression pattern based on TCGA data set and the tumor tissue array. Acetylated RNA immunoprecipitation sequencing was utilized to explore the role of NAT10 in mRNA ac4C modification. Translation efficiency and mRNA stability assay were applied to study the effect of NAT10-deletion on target genes. The nude mouse model and genetically engineered mice were conducted to further verify the characteristics of NAT10 in promoting BLCA progression and regulating downstream targets. RESULTS: NAT10 was essential for the proliferation, migration, invasion, survival and the stem-cell-like properties of bladder cancer cell lines. NAT10 was responsible for mRNA ac4C modification in BLCA cells, including BCL9L, SOX4 and AKT1. Deficient NAT10 in both xenograft and transgenic mouse models of bladder cancer reduced the tumor burden. Furthermore, acetylated RNA immunoprecipitation sequencing data and RNA immunoprecipitation qPCR results revealed that NAT10 is responsible for a set of ac4C mRNA modifications in bladder cancer cells. Inhibition of NAT10 led to a loss of ac4C peaks in these transcripts and represses the mRNA's stability and protein expression. Mechanistically, the ac4C reduction modification in specific regions of mRNAs resulting from NAT10 downregulation impaired the translation efficiency of BCL9L, SOX4 and AKT1 as well as the stability of BCL9L, SOX4. CONCLUSIONS: In summary, these findings provide new insights into the dynamic characteristics of mRNA's post-transcriptional modification via NAT10-dependent acetylation and predict a role for NAT10 as a therapeutic target in bladder cancer. HIGHLIGHTS: NAT10 is highly expressed in BLCA patients and its abnormal level predicts bladder cancer progression and low overall survival rate. NAT10 is necessary and sufficient for BLCA tumourigenic properties. NAT10 is responsible for ac4C modification of target transcripts, including BCL9L, SOX4 and AKT1. NAT10 may serve as an effective and novel therapeutic target for BLCA.

Mettl5 mediated 18S rRNA N6-methyladenosine (m6A) modification controls stem cell fate determination and neural function.

Ribosome RNA (rRNA) accounts for more than 80% of the cell's total RNA, while the physiological functions of rRNA modifications are poorly understood. Mutations of 18S rRNA m6A methyltransferase METTL5 cause intellectual disability, microcephaly, and facial dysmorphisms in patients, however, little is known about the underlying mechanisms. In this study, we identified METTL5 protein complex and revealed that METTL5 mainly interacts with RNA binding proteins and ribosome proteins. Functionally, we found that Mettl5 knockout in mESCs leads to the abnormal craniofacial and nervous development. Moreover, using Mettl5 knockout mouse model, we further demonstrated that Mettl5 knockout mice exhibit intellectual disability, recapitulating the human phenotype. Mechanistically, we found that Mettl5 maintains brain function and intelligence by regulating the myelination process. Our study uncovered the causal correlation between mis-regulated 18S rRNA m6A modification and neural function defects, supporting the important physiological functions of rRNA modifications in human diseases.

Corrigendum: Deficiency of Mettl3 in Bladder Cancer Stem Cells Inhibits Bladder Cancer Progression and Angiogenesis.

[This corrects the article DOI: 10.3389/fcell.2021.627706.].

Sox9-expressing cells promote regeneration after radiation-induced lung injury via the PI3K/AKT pathway.

BACKGROUND: Radiation-induced lung injury (RILI) is considered one of the most common complications of thoracic radiation. Recent studies have focused on stem cell properties to obtain ideal therapeutic effects, and Sox9 has been reported to be involved in stem cell induction and differentiation. However, whether Sox9-expressing cells play a role in radiation repair and regeneration remains unknown. METHODS: We successfully obtained Sox9CreER, RosatdTomato and RosaDTA mice and identified Sox9-expressing cells through lineage tracing. Then, we evaluated the effects of the ablation of Sox9-expressing cells in vivo. Furthermore, we investigated the underlying mechanism of Sox9-expressing cells during lung regeneration via an online single-cell RNA-seq dataset. RESULTS: In our study, we demonstrated that Sox9-expressing cells promote the regeneration of lung tissues and that ablation of Sox9-expressing cells leads to severe phenotypes after radiation damage. In addition, analysis of an online scRNA-Seq dataset revealed that the PI3K/AKT pathway is enriched in Sox9-expressing cells during lung epithelium regeneration. Finally, the AKT inhibitor perifosine suppressed the regenerative effects of Sox9-expressing cells and the AKT pathway agonist promotes proliferation and differentiation. CONCLUSIONS: Taken together, the findings of our study suggest that Sox9-expressing cells may serve as a therapeutic target in lung tissue after RILI.

Methyltransferase like 13 mediates the translation of Snail in head and neck squamous cell carcinoma.

Methyltransferase like 13 (METTL13), a kind of methyltransferase, is implicated in protein binding and synthesis. The upregulation of METTL13 has been reported in a variety of tumors. However, little was known about its potential function in head and neck squamous cell carcinoma (HNSCC) so far. In this study, we found that METTL13 was significantly upregulated in HNSCC at both mRNA and protein level. Increased METTL13 was negatively associated with clinical prognosis. And METTL13 markedly affected HNSCC cellular phenotypes in vivo and vitro. Further mechanism study revealed that METTL13 could regulate EMT signaling pathway by mediating enhancing translation efficiency of Snail, the key transcription factor in EMT, hence regulating the progression of EMT. Furthermore, Snail was verified to mediate METTL13-induced HNSCC cell malignant phenotypes. Altogether, our study had revealed the oncogenic role of METTL13 in HNSCC, and provided a potential therapeutic strategy.

Deficiency of Mettl3 in Bladder Cancer Stem Cells Inhibits Bladder Cancer Progression and Angiogenesis.

RNA N6-methyladenosine is a key step of posttranscriptional modulation that is involved in governing gene expression. The m6A modification catalyzed by Mettl3 has been widely recognized as a critical epigenetic regulation process for tumorigenic properties in various cancer cell lines, including bladder cancer. However, the in vivo function of Mettl3 in bladder cancer remains largely unknown. In our study, we found that ablation of Mettl3 in bladder urothelial attenuates the oncogenesis and tumor angiogenesis of bladder cancer using transgenic mouse model. In addition, conditional knockout of Mettl3 in K14+ bladder cancer stem cell population leads to inhibition of bladder cancer progression. Coupled with the global transcriptome sequencing and methylated RNA immunoprecipitation sequencing results, we showed that deletion of Mettl3 leads to the suppression of tyrosine kinase endothelial (TEK) and vascular endothelial growth factor A (VEGF-A) through reduced abundance of m6A peaks on a specific region. In addition, the depletion of Mettl3 results in the decrease in both messenger RNA (mRNA) and protein levels of TEK and VEGF-A in vitro. Taken together, Mettl3-mediated m6A modification is required for the activation of TEK-VEGF-A-mediated tumor progression and angiogenesis. Our findings may provide theoretical basis for bladder cancer treatment targeting Mettl3.

Tumor microenvironment in head and neck squamous cell carcinoma: Functions and regulatory mechanisms.

The tumor microenvironment has been recently reported to play a pivotal role in sustaining tumor cells survival and protecting them from immunotherapy and chemotherapy-induced death. It remains largely unknown how the specific signaling pathway exerts the tumor microenvironment in head and neck squamous cell carcinoma though previous studies have elucidated the regulatory mechanisms involve in tumor immune microenvironment, stromal cells, tumor angiogenesis and cancer stem cell. These components are responsible for tumor progression as well as anti-cancer therapy resistance, leading to rapid tumor growth and treatment failure. In this review, we focus on discussing the interaction between tumor cells and the surrounding components for better understanding of anti-cancer treatment ineffectiveness and its underlying molecular mechanisms.

A repetitive electron beam driver based on 6-stage linear transformer driver cavities.

A repetitive electron beam driver based on 6-stage Linear Transformer Driver (LTD) cavities is presented. Each cavity consists of two Blumlein pulse forming networks (BPFNs) sharing a laser trigger switch. Voltage adding is obtained by means of Linear Transformer (LT) technology. The LTD cavity consists of two BPFNs connected in parallel, an LT with a ratio of 1:1, and a laser-triggered spark switch. The energy efficiency of a single LTD was investigated. The results show that the energy efficiency of an L-type BPFN and an LT was 94.3% and 92.8%, respectively. An electron beam driver consisting of 6 such cavities was developed with an output voltage of 740 kV, a current of 12.3 kA, and a power of 9.1 GW. The repetition frequency operation results show that the electron beam driver can operate stably for 20 s at 25 Hz with a jitter of approximately 1.7 ns.

Bmi1 Severs as a Potential Tumor-Initiating Cell Marker and Therapeutic Target in Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a frequent malignant tumor with low 5-year overall survival. Targeting ESCC tumor-initiating cells (TICs) may provide a new research avenue to achieve better therapeutic effects of ESCC. However, the identity and characteristics of ESCC TICs remain poorly understood. Through genetic lineage tracing approach, we found that a group of Moloney murine leukemia virus insertion site 1- (Bmi1-) expressing cell populations present in the invasive front of the esophageal epithelium, providing a continuous flow of tumor cells for ESCC. Subsequently, we found that ablation of Bmi1+ cells from mice with ESCC led to inhibition of tumor growth. In addition, our results demonstrated that PTC-209, an inhibitor of Bmi1, was able to inhibit ESCC progression when combined with cisplatin. In summary, our data suggest that Bmi1+ cells serve as TICs in ESCC.

Higher vs. Lower DP for Ventilated Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis.

OBJECTIVES: Driving pressure (DP) has recently become a promising mediator for the identification of the effects of mechanical ventilation on outcomes in acute respiratory distress syndrome (ARDS). The aim of this study was to systematically and quantitatively update and assess the association between DP and mortality among ventilated patients with ARDS. METHODS: PubMed, the Cochrane Library, ISI Web of Knowledge, and Embase were systematically searched from inception to June 2018. Two investigators conducted the literature search study selection, data extraction, and quality evaluation independently. RevMan 5.3 software was used for all statistical analyses. RESULTS: A total of seven studies comprising 8010 patients were included in this meta-analysis. Higher DP showed a significant association with higher mortality (pooled risk ratio, 1.10; 95% [CI], 1.05-1.16; I 2 =58%). Sensitivity analysis indicated that one study significantly affected the stability of pooled results. One of the subgroups investigated, ARDS severity, could account for the heterogeneity. An exploratory post hoc subgroup analysis and higher DP significantly increased mortality in the mild to severe ARDS subgroup (RR 1.28; 95% [CI], 1.14-1.43; I 2 =0), but not in the moderate to severe ARDS subgroup (RR 1.18; 95% [CI], 0.95-1.46; I 2 =52%). CONCLUSION: Higher DP was significantly associated with an increased risk of death among ventilated patients with ARDS. But it did not seem to predict prognosis to moderate to severe ARDS. Future prospective randomized clinical trials are needed to verify the results of this meta-analysis and address the unresolved questions about optimum cutoff values for DP. TRIAL REGISTRATION: This trial is registered with PROSPERO (CRD42018102146), on 11 August 2018.

SHARPIN overexpression induces tumorigenesis in human prostate cancer LNCaP, DU145 and PC-3 cells via NF-κB/ERK/Akt signaling pathway.

SHARPIN emerges higher expression in prostate cancerous tissues than in benign prostate hyperplasia by means of immunohistochemistry in our previous study. In this work, we performed the gain of function assay and find that overexpression of SHARPIN in LNCaP, DU145 and PC-3 cells promoted cell proliferation, invasiveness and reduced apoptosis. Furthermore, SHARPIN overexpression displayed elevated Bcl-2 and Survivin expression and reduced levels of Bax, cleaved caspase-3. Meanwhile, entropic expression of SHARPIN increased the levels of phosphorylated p65, IkBα, ERK and Akt, were selectively increased in these cells. Collectively, our study unraveled the ability of SHARPIN overexpression to induce tumorigenesis of prostate cancer cells through the NF-kB/ERK/Akt pathway and transformation of apoptosis-associated proteins.