Infiltration and Polarization of Tumor-associated Macrophages Predict Prognosis and Therapeutic Benefit in Muscle-Invasive Bladder Cancer.

BACKGROUND: Muscle-invasive bladder cancer (MIBC) is an aggressive and heterogeneous malignancy. Tumor-associated macrophages (TAMs) are key infiltrating cell populations in the inflammatory microenvironment of malignant tumors including MIBC. It intrigues us to explore the clinical significance and immunoregulatory role of TAMs infiltration and polarization in MIBC. METHODS: A total of 141 patients with MIBC from Zhongshan Hospital and 391 patients with MIBC from The Cancer Genome Atlas (TCGA) database were included in this study. Moreover, 195 patients who received anti-PD-L1 therapy from the IMvigor210 trial were enrolled. Patients were categorized into three subtypes considering the infiltration level and polarization status of TAMs, denoted as TAMlow (Subtype I), TAMhigh&M2/M1low (Subtype II), and TAMhigh&M2/M1high (Subtype III). RESULTS: Subtype III suffered inferior prognosis, and Subtype II could benefit more from adjuvant chemotherapy (ACT). Subtype III was featured with increased pro-tumor cells and immunosuppressive cytokines, while Subtype II possessed more immunogenic cells infiltration with activated and tumoricidal properties. Subtype II and Subtype III presented basal/squamous-like characterization and showed additional prognostic merit beyond molecular classification. Subtype I exhibited elevated level of FGFR3 signature, while Subtype II had EGFR signaling activation and immunotherapeutic indication. Additionally, Subtype II patients were indeed highly sensitive to PD-L1 blockade therapy in IMvigor210 trial. CONCLUSION: The infiltration and polarization status of TAMs shaped distinct immune microenvironment with predictive significance for survival outcome, ACT benefit, and PD-L1 blockade therapy sensitivity in MIBC. Immune classification based on TAMs polarization and infiltration might provide tools to tailor chemotherapy and immunotherapy.

PFOS facilitates liver inflammation and steatosis: An involvement of NLRP3 inflammasome-mediated hepatocyte pyroptosis.

Perfluorooctane sulfonate (PFOS) is a fluorinated organic pollutant with substantial accumulation in mammalian liver tissues. However, the impact of chronic PFOS exposure on liver disease progression and the underlying molecular mechanisms remain elusive. Herein, we for the first time revealed that micromolar range of PFOS exposure initiates the activation of NLR pyrin domain containing 3 (NLRP3) inflammasome to drive hepatocyte pyroptosis. We showed that 5 mg/kg/day PFOS exposure may exacerbated liver inflammation and steatosis in high-fat diet (HFD)-fed mice with concurrently elevated expression of NLRP3 and caspase-1. PFOS exposure resulted in viability impairment and LDH release in BRL-3A rat liver cells. 25-100 µM concentrations of PFOS exposure activated the NLRP3 inflammasome, leading to consequent GSDMD cleavage, IL-1ß release and the initiation of pyroptosis in a dose-dependent manner, whereas treatment with 10 µM NLRP3 inhibitor MCC950 abrogated this effect. Moreover, pretreatment of 5 mM ROS scavenger N-acetyl-L-cysteine (NAC) ameliorated PFOS-induced NLRP3 inflammasome activation and pyroptosis. Collectively, our data highlight a pivotal role of pyroptotic death in PFOS-mediated liver inflammation and metabolic disorder.

Downregulation of Nedd4L predicts poor prognosis, promotes tumor growth and inhibits MAPK/ERK signal pathway in hepatocellular carcinoma.

Accumulating evidence indicates that the neural precursor cell-expressed, developmentally downregulated 4-like (Nedd4L) related with some tumor progression pathways and was found abnormally expressed in several kinds of solid cancers. However, the role and mechanism of Nedd4L in HCC remain unknown. This study was to assess the role of Nedd4L in HCC tumorigenesis and prognosis. The real-time quantitative RT-PCR and immunohistochemistry results revealed that Nedd4L was downregulated in HCC tissues compared to corresponding peri-noncancerous tissue, and HCC patients with low expression of Nedd4L exhibited poor prognosis assessed by Kaplan-Meier and Cox regression analysis in 78 HCC patients. Furthermore, knockdown of Nedd4L could significantly promote proliferation of HCC cells by CCK-8 and colony formation assays in vitro; whereas ectopic expression of Nedd4L resulted in attenuating proliferation in vitro and tumor growth in vivc determined by nude mice xenografts model. Mechanically, Nedd4L could phosphorylate ERK1/2 and regulate genes related with apoptosis. Collectively, Nedd4L plays a tumor suppressive role in HCC, possibly through triggering MAPK/ERK-mediated apoptosis, and Nedd4L downregulation may be a potential prognostic biomarker as well as a therapeutic target for HCC.

Expression pattern of BCCIP in hepatocellular carcinoma is correlated with poor prognosis and enhanced cell proliferation.

BCCIP was originally identified as a BRCA2- and CDKN1A- (Cip1/waf1/p21) interacting protein, also known as BCCIP. It has been reported to express in various types of cancers, including colorectal cancer (CRC), astrocytic brain tumors, and glioblastomas. However, the relationship between BCCIP expression and clinicopathological features of hepatocellular carcinoma (HCC) remains to be determined. Herein, we demonstrated that BCCIP was downregulated in clinical HCC tissues; its level was inversely correlated with multiple clinicopathological factors, such as tumor grade, tumor size, and Ki67 expression. Cox regression analysis of tumor samples revealed that BCCIP expression status was an independent prognostic factor for HCC patients' poor survival. Our study also indicated that BCCIP shutdown reduces p21 expression and accelerates G1 to S progression of LO2 hepatocytes significantly. Moreover, there is an interaction between BCCIP and p53 in hepatic L02 cells, and the downregulation of p21 expression by BCCIP is in a p53-dependent way. These findings revealed that BCCIP may play a significant role for the determination of HCC progression through its role in regulating cell growth. Thus, our results suggest that BCCIP is of potential interest for prognostic marker and therapeutic target of HCC.

Upregulated TRIM32 correlates with enhanced cell proliferation and poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and the sixth most prevalent human malignancies worldwide. However, the molecular mechanisms underlying hepatocarcinogenesis remain unclear. For HCC patients, there is not only a lack of effective therapeutic targets but also a lack of predictive or prognostic biomarkers. In this article, we reported that TRIM32 was obviously upregulated in HCC tumor tissues and HCC cell lines. Its expression patterns were positively correlated with histological grade, tumor sizes, and HBsAg of HCC patients. TRIM32 expression was a significant predictor for the overall survival time of HCC patients. Moreover, the overexpression of TRIM32 in cells accelerated the G1-S phase transition, promoted cell proliferation rates, and induced the resistance of HCC patients to oxaliplatin. All these findings suggest that TRIM32 might play important roles in the hepatocarcinogenesis. TRIM32 could be a novel direction to explore the mechanism underlying HCC pathogenesis.

Upregulated expression of polycomb protein Ring1 contributes to poor prognosis and accelerated proliferation in human hepatocellular carcinoma.

Ring finger protein 1 (Ring1) have recently been reported to be closely related to aggressive tumor features in multiple cancer types, including prostate cancer, non-small-cell lung cancer, and bladder cancer. However, the role of Ring1 in human hepatocarcinogenesis remains unclear. In this study, we aimed at investigating the latent role of Ring1 in hepatocellular carcinoma (HCC) development. The expression of Ring1 was evaluated using Western blot analysis in 8 paired fresh HCC tissues and immunohistochemistry on 98 paraffin-embedded sections from 2005 to 2008. Moreover, RNA interference, CCK-8, colony formation, and flow-cytometry analyses were performed to investigate the role of Ring1 in the regulation of HCC cell proliferation. Compared with adjacent normal tissues, the level of Ring1 was significantly increased in HCC specimens. High expression of Ring1 was associated with histological grade (P = 0.011) and tumor size (P = 0.004), and Ring1 expression was positively related with the proliferation marker Ki-67 (P < 0.001). Moreover, knocking down Ring1 induced growth impairment and G1/S cell cycle arrest in HCC cells. Kaplan-Meier survival curves showed that high expression of Ring1 indicated poor prognosis of HCC (P = 0.03). On the basis of these results, we proposed that the expression of Ring1 protein may be a novel indicator of HCC prognosis.

High CHMP4B expression is associated with accelerated cell proliferation and resistance to doxorubicin in hepatocellular carcinoma.

Charged multivesicular body protein 4B (CHMP4B), a subunit of the endosomal sorting complex required for transport (ESCRT)-III complex, plays an important part in cytokinetic membrane abscission and the late stage of mitotic cell division. In this study, we explored the prognostic significance of CHMP4B in human hepatocellular carcinoma (HCC) and its impact on the physiology of HCC cells. Western blot and immunohistochemistrical analyses showed that CHMP4B was significantly upregulated in HCC tissues, compared with adjacent non-tumorous tissues. Meanwhile, clinicopathological analysis revealed that high CHMP4B expression was correlated with multiple clinicopathological variables, including AFP, cirrhosis, AJCC stage, Ki-67 expression, and poor prognosis. More importantly, univariate and multivariate survival analyses demonstrated that CHMP4B served as an independent prognostic factor for survival of HCC patients. Using HCC cell cultures, we found that the expression of CHMP4B was progressively upregulated after the release from serum starvation. To verify whether CHMP4B could regulate the proliferation of HCC cells, CHMP4B was knocked down through the transfection of CHMP4B-siRNA oligos. Flow cytometry and CCK-8 assays indicated that interference of CHMP4B led to cell cycle arrest and proliferative impairment of HCC cells. Additionally, depletion of CHMP4B expression could increase the sensitivity to doxorubicin in HepG2 and Huh7 cells. Taken together, our results implied that CHMP4B could be a promising prognostic biomarker as well as a potential therapeutic target of HCC.

Downregulation of UBE2Q1 is associated with neuronal apoptosis in rat brain cortex following traumatic brain injury.

Aberrant functionality of the ubiquitin proteasome system (UPS) has been implicated in the pathology of various neurological disorders. Although it has been reported that the expressions of various UPS components were altered significantly following traumatic brain injury (TBI), detailed information on the subject remains largely unclear. In the study, using microarray assay, we identified a gene encoding ubiquitin-conjugating enzyme E2Q1 (UBE2Q1) that was significantly downregulated during TBI. Western blot and immunohistochemical analyses verified the reduced expression of UBE2Q1 in ipsilateral brain cortex adjacent to the lesion site compared with the contralateral and sham-operated ones. Double-immunofluorescence staining indicated that UBE2Q1 was expressed mainly in the nucleus of neurons, with a minority in astrocytes in normal cortex. In addition, we observed a remarkable reduction in the number of UBE2Q1-positive neurons following brain trauma. Furthermore, we showed that TBI resulted in a significant increase in the levels of p53, bax, p21 and active caspase 3 in brain cortex, which was correlated with decreased expression of UBE2Q1. We also found that knockdown of UBE2Q1 apparently increased the level of p53, whereas overexpressing UBE2Q1 attenuated cellular p53 level in PC12 neuronal cells. Accordingly, interference with UBE2Q1 augmented H2O2-induced apoptosis of PC12 cells. Taken together, our findings indicate that UBE2Q1 might play an important role in the neuropathological process of TBI through modulating p53 signaling.

The downregulation of ErbB3 binding protein 1 (EBP1) is associated with poor prognosis and enhanced cell proliferation in hepatocellular carcinoma.

ErbB3 binding protein 1 (EBP1) has been recently reported to function as a tumor suppressor in the progression of multiple cancers, including breast cancer, prostate cancer, salivary adenoid cystic carcinoma (ACC), and oral squamous cell carcinoma (OSCC). However, the expression and physiological significance of EBP1 in hepatocellular carcinoma (HCC) remain unclear. In the study, we showed that EBP1 was significantly downregulated in clinical HCC specimens, and that decreased expression of EBP1 was associated with enhanced proliferation in HCC cells. Western blot and immunohistochemical analyses revealed that EBP1 was remarkably downregulated in HCC tissues compared with the adjacent normal ones. The levels of EBP1 were significantly associated with histological grade (P = 0.034), tumor size (P = 0.001), and Ki67 expression (P < 0.001) in HCC specimens. Univariate and multivariate analyses showed that EBP1 could serve as an independent prognostic indicator of patients' survival. Serum starvation and refeeding assay indicated that EBP1 was accumulated in growth-arrested HCC cells, and was progressively decreased when cells entered into S phase. Moreover, the depletion of EBP1 induced growth acceleration and cell cycle progression in L02 hepatocytes. On the basis of these findings, we conclude that EBP1 may be a valuable prognostic marker and promising therapeutic target of HCC.

The upregulation of Annexin A2 by TLR4 pathway facilitates lipid accumulation and liver injury via blocking AMPK/mTOR-mediated autophagy flux during the development of non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. In this study, we aimed to investigate the role and regulatory mechanism of Annexin A2 (ANXA2) in the pathogenesis of NAFLD. METHODS: Histological analyses and ELISA were used to illuminate the expression of ANXA2 in NAFLD and healthy subjects. The role of ANXA2 was evaluated using high-fat diet (HFD)-fed mice via vein injection of adeno-associated viruses (AAV) knocking down ANXA2 or non-targeting control (NC) shRNAs. Moreover, HepG2 and LO2 cells were employed as in vitro hepatocyte models to investigate the expression and function of ANXA2. RESULTS: ANXA2 was confirmed to be one of three hub genes in liver injury, and its expression was positively correlated with NAFLD activity score (NAS) and macrophage infiltration in NAFLD. Moreover, ANXA2 was significantly upregulated in NAFLD patients and HFD-fed mice. LPS/TLR4 pathway strongly upregulated ANXA2 expression, which is mediated by direct ANXA2 promoter binding by TLR4 downstream NF-κB p65 and c-Jun transcription factors. Increased ANXA2 expression was correlated with decreased autophagy flux and autophagy was activated by the depletion of ANXA2 in the models of NAFLD. Furthermore, ANXA2 interference led to the activation of AMPK/mTOR signaling axis, which may play a causal role in autophagy flux and the amelioration of steatosis. CONCLUSIONS: ANXA2 is a pathological predictor and promising therapeutic target for NAFLD. ANXA2 plays a crucial role in linking inflammation to hepatic metabolic disorder and injury, mainly through the blockage of AMPK/mTOR-mediated lipophagy.

High Expression of CSF-1R Predicts Poor Prognosis and CSF-1Rhigh Tumor-Associated Macrophages Inhibit Anti-Tumor Immunity in Colon Adenocarcinoma.

Background: Colony stimulating factor 1 receptor (CSF-1R) is a single channel III transmembrane receptor tyrosine kinase (RTK) and plays an important role in immune regulation and the development of various cancer types. The expression of CSF-1R in colon adenocarcinoma (COAD) and its prognostic value remain incompletely understood. Therefore, we aim to explore the prognostic value of CSF-1R in COAD and its relationship with tumor immunity. Methods: CSF-1R expression in a COAD cohort containing 103 patients was examined using immunohistochemistry (IHC). The relationship between CSF-1R expression and clinicopathological parameters and prognosis was evaluated. Dual immunofluorescence staining was conducted to determine the localization of CSF-1R in COAD tissues. Univariate and multivariate Cox regression analysis were performed to evaluate independent prognostic factors. Transcriptomic profiles of CSF-1Rhigh and CSF-1Rlow tumor-associated macrophages (TAMs) were investigated. Gene enrichment analysis was used to explore the signal pathways related to CSF-1R. In addition, the relationship between CSF-1R in tumor microenvironment (TME) and tumor immunity was also studied. Results: IHC analysis showed that CSF-1R was overexpressed in COAD, and higher expression was associated with shorter overall survival (OS). Immunofluorescence staining showed that CSF-1R was co-localized with macrophage marker CD68. Univariate and multivariate Cox regression analysis showed that CSF-1R was an independent prognostic factor for COAD. The results of gene enrichment analysis showed that CSF-1R was involved in tumor immune response and regulation of TME. In addition, CSF-1R was significantly correlated with TME, immune cell infiltration, TMB, MSI, Neoantigen, and immune checkpoint molecules. Conclusion: CSF-1R can serve as an independent prognostic factor of COAD and promising immunotherapeutic target of COAD.

Nucleolus and Nucleolar Stress: From Cell Fate Decision to Disease Development.

Besides the canonical function in ribosome biogenesis, there have been significant recent advances towards the fascinating roles of the nucleolus in stress response, cell destiny decision and disease progression. Nucleolar stress, an emerging concept describing aberrant nucleolar structure and function as a result of impaired rRNA synthesis and ribosome biogenesis under stress conditions, has been linked to a variety of signaling transductions, including but not limited to Mdm2-p53, NF-κB and HIF-1α pathways. Studies have uncovered that nucleolus is a stress sensor and signaling hub when cells encounter various stress conditions, such as nutrient deprivation, DNA damage and oxidative and thermal stress. Consequently, nucleolar stress plays a pivotal role in the determination of cell fate, such as apoptosis, senescence, autophagy and differentiation, in response to stress-induced damage. Nucleolar homeostasis has been involved in the pathogenesis of various chronic diseases, particularly tumorigenesis, neurodegenerative diseases and metabolic disorders. Mechanistic insights have revealed the indispensable role of nucleolus-initiated signaling in the progression of these diseases. Accordingly, the intervention of nucleolar stress may pave the path for developing novel therapies against these diseases. In this review, we systemically summarize recent findings linking the nucleolus to stress responses, signaling transduction and cell-fate decision, set the spotlight on the mechanisms by which nucleolar stress drives disease progression, and highlight the merit of the intervening nucleolus in disease treatment.

Emerging Roles of the Nervous System in Gastrointestinal Cancer Development.

Our understanding of the fascinating connection between nervous system and gastrointestinal (GI) tumorigenesis has expanded greatly in recent years. Recent studies revealed that neurogenesis plays an active part in GI tumor initiation and progression. Tumor-driven neurogenesis, as well as neurite outgrowth of the pre-existing peripheral nervous system (PNS), may fuel GI tumor progression via facilitating cancer cell proliferation, chemoresistance, invasion and immune escape. Neurotransmitters and neuropeptides drive the activation of various oncogenic pathways downstream of neural receptors within cancer cells, underscoring the importance of neural signaling pathways in GI tumor malignancy. In addition, neural infiltration also plays an integral role in tumor microenvironments, and contributes to an environment in favor of tumor angiogenesis, immune evasion and invasion. Blockade of tumor innervation via denervation or pharmacological agents may serve as a promising therapeutic strategy against GI tumors. In this review, we summarize recent findings linking the nervous system to GI tumor progression, set the spotlight on the molecular mechanisms by which neural signaling fuels cancer aggressiveness, and highlight the importance of targeting neural mechanisms in GI tumor therapy.

ß2-adrenergic receptor drives the metastasis and invasion of pancreatic ductal adenocarcinoma through activating Cdc42 signaling pathway.

Recent investigations indicate that ß2-adrenergic receptor (ß2-AR) signaling may facilitate the progression of various tumors, whose underlying mechanisms remain largely elusive. In the present study, we showed that ß2-AR recruited Cdc42 in response to isoproterenol (ISO, a ß-AR selective agonist) exposure in pancreatic ductal adenocarcinoma (PDAC) cells. The association of ß2-AR and Cdc42 promoted the activation of Cdc42, as revealed by increased levels of Cdc42-GTP, and co-incubation with ß2-AR antagonist abrogated ISO-induced activation of Cdc42. ß2-AR-mediated Cdc42 activation further led to the phosphorylation of downstream PAK1, LIMK1 and Merlin. Furthermore, we showed that the activation of ß2-AR/Cdc42 signaling facilitated the migration and invasion of PDAC cells. In addition, ß2-AR and Cdc42 were overexpressed in PDAC specimens, compared with adjacent non-tumor tissues. High expression of ß2-AR and Cdc42 were correlated with lymph node metastasis and TNM stage in PDAC patients. Finally, we showed that overexpression of ß2-AR and Cdc42 were indicative of unfavorable prognosis in PDAC patients. Taken together, our findings suggested that ß2-AR might facilitate Cdc42 signaling to drive the migration and invasion of PDAC cells, consequently resulting in the metastasis and dismal prognosis of PDAC. These studies highlight targeting ß2-AR/Cdc42 signaling as a therapeutic strategy against PDAC.

Immune inactivation by CD47 expression predicts clinical outcomes and therapeutic responses in clear cell renal cell carcinoma patients.

BACKGROUND: CD47 has been identified as a phagocytosis checkpoint conferring poor clinical outcomes in various cancer types. A flurry of clinical trials designed to evaluate agents that block CD47 have been initiated. We aimed to explore the clinical significance of CD47 and its correlation with immune infiltration and molecular features in clear cell renal cell carcinoma (ccRCC). METHODS: 235 tumor tissue microarray specimens of ccRCC patients from Zhongshan Hospital, 530 ccRCC patients from The Cancer Genome Atlas and 726 ccRCC patients from JAVELIN Renal 101 study were analyzed. CD47 expression and immune contexture were examined by immunohistochemistry and CIBERSORT algorithm. Survival analyses were conducted through Kaplan-Meier curves and Cox regression model. RESULTS: We demonstrated that ccRCC patients with high CD47 expression exhibited inferior overall survival and recurrence-free survival. CD47 expression associated with heavily immune infiltrated but immunosuppressed microenvironment. CD8+ T cells infiltration had discordant prognostic value based on CD47 expression, where high CD8+ T cell infiltration was associated with worse clinical outcome in CD47hi patients and with favorable prognosis in CD47lo patients. Patients with mutated PBRM1 and SETD2 correlated with decreased CD47 mRNA expression. Patients with higher CD47 expression possessed improved PFS in ICI + VEGFR TKI combination therapy. CONCLUSIONS: CD47 expression was an independent prognosticator of clinical outcome for ccRCC patients. CD47 expression correlated with ccRCC molecular classification and response to combination therapy. The phagocytosis checkpoint CD47 could be applied as an attractive candidate for immunotherapeutic approach in ccRCC.

Corrigendum: Increased CDC6 Expression Associates With Poor Prognosis in Patients With Clear Cell Renal Cell Carcinoma.

[This corrects the article DOI: 10.3389/fonc.2021.666418.].

Impact of intratumoural CD73 expression on prognosis and therapeutic response in patients with gastric cancer.

AIM: CD73 overexpression has been reported in several malignancies and is considered to be a novel immune checkpoint. However, the role and significance of CD73 in gastric cancer (GC) still remain obscure. We aim to investigate the role of CD73 expression in predicting prognosis, shaping immune contexture and guiding therapeutic strategy in GC. METHODS: The study enrolled four independent cohorts with a total of 902 patients with GC. CD73 expression and immune contexture were examined by immunohistochemistry, single-sample gene set enrichment analysis and flow cytometry. Clinical outcomes of patient subgroups were evaluated using the Kaplan-Meier curves and Cox proportional hazard analysis. All statistical tests were two-sided. RESULTS: CD73 was identified as an independent adverse prognostic factor for survival in GC. CD73high tumours showed a specific microenvironment with more CD8+ T cell infiltration, but these CD8+ T cells displayed a dysfunctional phenotype. Furthermore, the CD73 (NT5E) mRNA level was associated with the Cancer Genome Atlas molecular subtypes, and NT5E high tumours showed significant fibroblast growth factor receptor 2 activation and vascular endothelial growth factor and receptor enrichment. In addition, CD73high tumours indicated better chemotherapeutic responsiveness to fluorouracil yet a worse objective response rate to pembrolizumab in GC. CONCLUSIONS: High CD73 expression indicated an immunoevasive contexture with CD8+ T cell dysfunction and represented an independent predictor for adverse clinical outcomes. As a potential immunotherapeutic target, CD73 could potentially be a novel biomarker for adjuvant chemotherapy, targeted therapies and immunotherapy. The crucial role of CD73 in the therapeutic landscape of GC needs further validation retrospectively and prospectively.

Nicotine triggers islet ß cell senescence to facilitate the progression of type 2 diabetes.

Cigarette smoking is a well-recognized risk factor for type 2 diabetes (T2DM), and may result in islet ß cell damage and impaired insulin secretion. However, the underlying mechanisms remain largely elusive. In the present study, we demonstrated that nicotine induced premature senescence of pancreatic ß cells in vitro and in vivo. The senescence-associated ß-galactosidase (SA-ß-Gal) assay showed that nicotine exposure induced apparent senescence phenotype of ß-TC-6 cells at an initiating dose of 100 µM and starting from 12 h. In addition, 100 and 500 µM of nicotine exposure altered the expression of senescence marker proteins, such as p16, p19 and p21. Furthermore, we uncovered that the levels of intracellular Ca2+ and reactive oxygen species (ROS) were significantly elevated in ß-TC-6 cells following exposure to 100 and 500 µM nicotine, while calcium channel blocker can reverse this effect. Furthermore, the senescence-inducing phenotype was confirmed in rat insulinoma INS-1 cells at a similar dose range, whereas blockade of nAChRs, calcium and ROS led to apparent impairment of senescence. Finally, we found that administration with 100 and 200 µg/mL nicotine in drinking water for 28 days significantly exacerbated aberrant glucose homeostasis in a mouse model of fat-induced T2DM. Of great intrigue, pancreatic ß cells exhibited significantly enhanced senescence following nicotine administration. Taken together, this study suggests that premature senescence plays a pivotal role in nicotine-triggered ß cell destruction and glucose intolerance, providing a theoretical basis for targeted prevention and treatment of smoking-induced T2DM.

Blockade of DC-SIGN+ Tumor-Associated Macrophages Reactivates Antitumor Immunity and Improves Immunotherapy in Muscle-Invasive Bladder Cancer.

Tumor-associated macrophages (TAM) play an indispensable role in the modulation of the cancer immune microenvironment. Despite the fact that TAMs may exert both antitumor and protumor activities, the molecular mechanisms involved remain poorly understood. Here, we characterized a subpopulation of TAMs expressing dendritic cell-specific C-type lectin (DC-SIGN) and investigated its relevance to the prognosis and immune microenvironment of muscle-invasive bladder cancer (MIBC). DC-SIGN+ TAMs were abundant in a significant proportion of human MIBC specimens. High levels of DC-SIGN+ TAMs were associated with dismal prognosis and unresponsiveness to adjuvant chemotherapy in MIBC. Notably, multiple anti-inflammatory cytokines were enriched in DC-SIGN+ TAMs. RNA-seq analysis revealed that multiple M2-like signaling pathways were significantly upregulated in DC-SIGN+ TAMs. High infiltration of DC-SIGN+ TAMs was associated with CD8+ T-cell tolerance in MIBC. Moreover, abrogating DC-SIGN function using a neutralizing antibody led to impaired expression of anti-inflammatory cytokines and augmented PD-1 inhibitor pembrolizumab-mediated cytotoxic effects of CD8+T cells toward MIBC cells. In summary, these results suggest that DC-SIGN+ TAM infiltration is closely linked to a protumor immune microenvironment and may serve as a promising therapeutic target in the immunotherapy of MIBC. SIGNIFICANCE: DC-SIGN+ TAMs have an immunosuppressive and tumor-promoting function and may serve as a prognostic indicator and therapeutic target in MIBC.