ARRB1 Drives Gallbladder Cancer Progression by Facilitating TAK1/MAPK Signaling Activation.

Gallbladder carcinoma (GBC) is the most common malignancy of the biliary tract, with a dismal 5-year survival of 5%. Recently, ARRB1, as a molecular scaffold, has been proposed to participate in the progression of multiple malignancies. However, the effect and regulatory mechanisms of ARRB1 in GBC have not been investigated. Our study aimed to explore the biological functional status and the possible molecular mechanisms of ARRB1 with respect to GBC progression. The survey showed that human GBC tissues exhibited increased levels of ARRB1 compared with normal tissues, and the high expression of ARRB1 was associated with poor prognosis of GBC patients. A series of in vitro and in vivo functional experiments based on knockdown of ARRB1 uncovered that ARRB1 enhanced GBC cell proliferation, migration, and invasion. Furthermore, we reported that TAK1, a component of the TNF /MAPK pathway, is a vital downstream effector of ARRB1. In addition, siTAK1 could abolish the functional changes between ARRB1 overexpression GBC cells and control ones. Our data revealed that ARRB1 facilitated the carcinogenesis and development of GBC through TNF/TAK1/MAPK axis, suggesting that ARRB1 may be a promising biomarker and treatment target for GBC patients.

Ectopic expression of LAG-3 in non-small-cell lung cancer cells and its clinical significance.

BACKGROUND: Lymphocyte activation gene 3 (LAG-3, also known as CD223) is an immune checkpoint molecule expressed on various types of lymphocytes, and it is mainly involved in maintaining immune homeostasis. However, there are currently no data on LAG-3 expression in non-small-cell lung cancer cells. METHODS: Human lung cancer cells were cultured using conventional methods. The expression of LAG-3 was measured by Western blot and flow cytometry. Between April 2018 and May 2019, we collected 52 surgical specimens of stage I-III non-small-cell lung cancer (NSCLC). Fourteen samples of benign lung tissue lesions were collected as the control group, and the expression levels of LAG-3 in the lung cancer cells and tissue samples were measured via immunohistochemistry. RESULTS: Western blots showed that LAG-3 was expressed in lung cancer cell lines. There was significant difference in the LAG-3 expression levels in the NSCLC cells and benign lung tissue (χ2  = 13.055, P = .0003). The LAG-3 expression level was significantly associated with the NSCLC clinical stage, and LAG-3 expression was significantly higher in stage III patients (P < .05). CONCLUSION: LAG-3 is expressed in NSCLC tumor cells. Furthermore, LAG-3 not only is expressed in tumor-infiltrating lymphocytes in NSCLC patients but also is ectopically expressed in tumor cells and associated with TNM stage.

MyD88-silenced dendritic cells induce T-cell hyporesponsiveness and promote Th2 polarization in vivo.

BACKGROUND AIMS: Previous studies have determined that the absence of MyD88 enhances the tolerogenicity of dendritic cells (DCs), suggesting that inhibiting innate immunity may be a potential strategy to facilitate the induction of transplant tolerance by DCs. However, the underlying mechanism remains unclear. METHODS: Recipient rats were preconditioned with MyD88 gene-silenced DCs. In vivo distribution of infused MyD88 gene-silenced DCs in lymphatic organs was also analyzed. The response ability of recipient spleen T cells was determined by cell proliferation assay. The concentrations of interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-5 and IL-10 in cell culture supernates were measured with sandwich enzyme-linked immunosorbent assay. Flow cytometry was used to detect the transfection efficiency and CD4(+)CD25(+)FoxP3(+) T cell assay. RESULTS: After being infused into allogenic recipient rats, both MyD88-or control-silenced DCs were efficiently trafficked to the lymphatic organs and liver. The ex vivo analysis of proliferative responses revealed the donor-specific inhibition of alloimmune reactivity by MyD88-silenced DCs. This effect was associated with the marked inhibition of Th1-type cytokine production (IFN-γ and IL-2) but with significant promotion of Th2 type cytokine secretion (IL-4 and IL-5). CONCLUSIONS: It was demonstrated that T cells from recipients pretreated with MyD88-silenced DCs exhibited significantly reduced secretion of IFN-γ and IL-2 but markedly enhanced production of IL-4 and IL-5.

Assessment of CAR- or CD46-dependent adenoviral vector-mediated TRAIL gene therapy in clinical adenocarcinoma lung cancer cells.

Adenoviral vector-mediated transfer of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can be a powerful approach to lung cancer therapy. However, the efficiency of adenoviral vector gene transfer and the sensitivity to TRAIL-induced apoptosis in the context of adenoviral vector gene transfer have yet to be characterized in primary lung cancers. In this study, we investigated the expression of adenoviral receptor CD46 expression in primary lung cancer cells. In contrast to previous reports on enhanced CD46 expression in various types of cancer cells, we show a significantly higher CD46 expression in lung adenocarcinomas compared to lung squamous cell carcinomas. Using Ad5-GFP and Ad5F35-GFP vectors, we demonstrated an improved gene transfer efficiency in primary lung cancer cells by the Ad5F35 vector. The apoptosis induction effect mediated by Ad5-TRAIL and Ad5F35-TRAIL vector gene transfer was compared in cells from 10 lung adenocarcinomas. Of 5 lung cancers in which apoptosis was induced, 2 had an enhanced effect by Ad5F35-TRAIL vector gene transfer compared to Ad5-GFP. Thus, these results indicate a method to identify TRAIL-sensitive primary lung cancers, which will also facilitate the analysis of resistance mechanisms in lung cancers.

Coxsackievirus and adenovirus receptor expression in non-malignant lung tissues and clinical lung cancers.

Adenoviral vector mediated gene delivery has been applied in clinical trials and mechanistic studies to explore new treatment approaches for lung cancers. The expression of coxsackievirus adenovirus receptor (CAR), the primary receptor for the most commonly used adenovirus serotype 5 (Ad5)-based vectors, predominantly determines the permissiveness of lung cancer cells. CAR expression is also suggested to modulate tumor cell proliferation capacity. Here, we studied CAR expression in archival lung cancer specimens by using well-characterized CAR 72 antibodies. High levels of CAR expression were observed in most of the 32 cases of squamous cell carcinoma lung cancers and in all the five cases of small cell lung cancers investigated. In contrast, high levels of CAR expression were detected only in 6 of 22 adenocarcinoma lung cancers. The relative levels of CAR expression did not correlate with the pathologic grade in lung cancers, and was thus inconsistent with a role of modulating cancer cell proliferation. Of note, CAR expression was not detected in non-malignant alveolar cells. Our data suggest a preferred utility of Ad5 vector mediated gene delivery to squamous cell carcinoma lung cancers, small cell lung cancers, but not to the majority of adenocarcinoma lung cancers.